BILLING CODE 3510-22-P
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 240524-0146]
RIN 0648-BL96
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine
Mammals Incidental to the New England Wind Project, Offshore Massachusetts
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Final rule; notification of issuance of letter of authorization.
SUMMARY: In accordance with the regulations implementing the Marine Mammal
Protection Act (MMPA), as amended, NMFS hereby promulgates regulations to govern
the incidental taking of marine mammals by Avangrid Renewables, LLC, (Avangrid), the
parent company of the original applicant, Park City Wind, LLC (Park City Wind), during
the construction of the New England Wind Project (the Project), an offshore wind energy
project, developed in two phases, known as Park City Wind (phase 1) and
Commonwealth Wind (phase 2), in Federal and State waters off of Massachusetts,
specifically within the Bureau of Ocean Energy Management (BOEM) Commercial
Lease of Submerged Lands for Renewable Energy Development on the Outer Continental
Shelf (OCS) Lease Areas (OCS-A 0534 and OCS-A 0561) and the southwest (SW)
portion of Lease Area OCS-A 0501 (collectively referred to as the Lease Area), and
along an export cable routes to sea-to-shore transition points (collectively, the Project
Area), over the course of 5 years (March 27, 2025, through March 26, 2030). The
proposed rule for this action concerned only Lease Areas OCS-A 0534 and the SW
portion of Lease Area OCS-A 0501. However, after publication of the proposed rule,
Lease Area OCS-A 0534 was segregated into two portions: OCS-A 0534 and OCS-A

0561. Phase 1 remained with Park City Wind (OCS-A 0534) while phase 2 (OCS-A
0561) was assigned to a sister company named Commonwealth Wind, LLC (subsidiary
of Avangrid). As a result of this, Park City Wind requested that the Letter of
Authorization (LOA), if issued, be issued to Avangrid, who would oversee the
construction of the both phases of the Project by its two subsidiaries. These regulations,
which allow for the issuance of a LOA for the incidental take of marine mammals during
construction-related activities within the Project Area during the effective dates of the
regulations, prescribe the permissible methods of taking and other means of effecting the
least practicable adverse impact on marine mammal species or stocks and their habitat as
well as requirements pertaining to the monitoring and reporting of such taking.
DATES: This rule is effective from March 27, 2025, through March 26, 2030.
FOR FURTHER INFORMATION CONTACT: Karolyn Lock, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
A copy of the application and supporting documents, as well as a list of the
references cited in this document, may be obtained online at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-takeauthorizations-other-energy-activities-renewable. In case of problems accessing these
documents, please call the contact listed above (see FOR FURTHER INFORMATION
CONTACT).
Purpose and Need for Regulatory Action
This final rule, as promulgated, provides a framework under the authority of the
MMPA (16 U.S.C. 1361 et seq.) for NMFS to authorize the take of marine mammals
incidental to construction of the Project within the Project Area. NMFS received a
request from the applicant to incidentally take a small number of marine mammals from

39 species of marine mammals. After reviewing the request and making the erquired
findings, NMFS could authorize the take, by harassment only, of 38 species, representing
38 stocks (19 species by Level A harassment and all 38 species by Level B harassment)
incidental to the applicant’s 5 years of construction activities. The applicant did not
request and NMFS neither anticipates nor allows take by serious injury or mortality
incidental to the specified activities in this final rulemaking.
Legal Authority for the Final Action
The MMPA prohibits the “take” of marine mammals, with certain exceptions.
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) direct the Secretary
of Commerce (as delegated to NMFS) to allow, upon request, the incidental, but not
intentional, taking of small numbers of marine mammals by U.S. citizens who engage in
a specified activity (other than commercial fishing) within a specified geographical
region if certain findings are made, regulations are promulgated (when applicable), and
public notice and an opportunity for public comment are provided.
Authorization for incidental takings shall be granted if NMFS finds that the taking
will have a negligible impact on the species or stock(s) and will not have an unmitigable
adverse impact on the availability of the species or stock(s) for taking for subsistence
uses (where relevant). If such findings are made, NMFS must prescribe the permissible
methods of taking, “other means of effecting the least practicable adverse impact” on the
affected species or stocks and their habitat, paying particular attention to rookeries,
mating grounds, and areas of similar significance, and on the availability of the species or
stocks for taking for certain subsistence uses (referred to as “mitigation”); and
requirements pertaining to the monitoring and reporting of such takings.
As noted above, the applicant did not request and NMFS neither anticipates nor
would allow take by serious injury or mortality incidental to the specified activities in this

final rulemaking. Relevant definitions of MMPA statutory and regulatory terms are
included below:
●

Citizen – individual U.S. citizens or any corporation or similar entity if it

is organized under the laws of the United States or any governmental unit defined in 16
U.S.C. 1362(13) (50 CFR 216.103);
●

Take – to harass, hunt, capture, or kill, or attempt to harass, hunt, capture,

or kill any marine mammal (16 U.S.C. 1362);
●

Incidental Harassment, Incidental Taking and Incidental, but not

Intentional, Taking – an accidental taking. This does not mean that the taking is
unexpected, but rather it includes those takings that are infrequent, unavoidable or
accidental (50 CFR 216.103);
●

Serious Injury – any injury that will likely result in mortality (50 CFR

●

Level A harassment – any act of pursuit, torment, or annoyance which has

216.3);

the potential to injure a marine mammal or marine mammal stock in the wild (16 U.S.C.
1362; 50 CFR 216.3); and
●

Level B harassment – any act of pursuit, torment, or annoyance which has

the potential to disturb a marine mammal or marine mammal stock in the wild by causing
disruption of behavioral patterns, including, but not limited to, migration, breathing,
nursing, breeding, feeding, or sheltering (16 U.S.C. 1362).
Section 101(a)(5)(A) of the MMPA and the implementing regulations at 50 CFR
part 216, subpart I, provide the legal basis for proposing and, if appropriate, issuing this
rule containing 5-year regulations and associated LOA. This final rule also establishes
required mitigation, monitoring, and reporting requirements for the in-water specified
activities.

Summary of Major Provisions within the Final Rule
The major provisions within this final rule include:
●

Allowing NMFS to authorize, under a LOA, the take of small numbers of

marine mammals by Level A harassment and/or Level B harassment (50 CFR 217.322)
incidental to the Project and prohibiting take of such species or stocks in any manner not
permitted (50 CFR 217.323) (e.g., mortality or serious injury);
●

Establishing a seasonal moratorium on impact pile driving and drilling

during January 1 through April 30, annually, as well as avoiding impact pile driving and
drilling in December in order to minimize impacts to North Atlantic right whales
(Eubalaena glacialis). Impact pile driving and drilling must not be planned in December;
however, it may then only occur if necessary to complete the Project within a given year
and with prior approval by NMFS (e.g., as a result of unforeseen circumstances such as
unanticipated weather delays, unexpected technical difficulties). LOA Holder must notify
NMFS in writing by September 1 of that year that pile driving or drilling cannot be
avoided and circumstances are expected to necessitate pile driving or drilling in
December;
●

Establishing a seasonal moratorium on vibratory pile driving (i.e.,

vibratory setting of piles) during December 1 through May 31, annually, to minimize
impacts to North Atlantic right whales (Eubalaena glacialis);
●

Establishing a seasonal moratorium on the detonation of unexploded

ordnance or munitions and explosives of concern (UXO/MEC) from December 1 through
May 31, annually. UXO/MEC detonation must not be planned for December or May in
order to minimize impacts to North Atlantic right whales (Eubalaena glacialis); however,
UXO/MEC detonation may occur in December or May with NMFS' approval on a caseby-case basis only.

●

Requirements for UXO/MEC detonations to only occur if all other means

of removal are impracticable (i.e., As Low As Reasonably Practicable (ALARP) risk
mitigation procedure)), conducting UXO/MEC detonations during daylight hours only,
and limiting detonations to one per 24 hour period;
●

Conducting both visual and passive acoustic monitoring (PAM) by

trained, NMFS-approved Protected Species Observers (PSOs) and PAM operators before,
during, and after select in-water construction activities;
●

Establishing clearance and shutdown zones for all in-water construction

activities to prevent or reduce the risk of Level A harassment and to minimize the risk of
Level B harassment, including a delay or shutdown of foundation impact pile driving and
delay to UXO/MEC detonation if a North Atlantic right whale is observed at any distance
by PSOs or acoustically detected within certain distances;
●

Establishing minimum visibility and PAM monitoring zones during

foundation installation activities (i.e., impact pile driving, vibratory pile driving, and
drilling);
●

Requiring use of at least two noise attenuation devices during all

foundation installation activities and UXO/MEC detonations to reduce noise levels to
those modeled assuming a broadband 10 decibel (dB) attenuation;
●

Requiring sound field verification (SFV) requirements during foundation

installation and UXO/MEC detonations to measure in situ noise levels for comparison
against the modeled results.
●

Requiring SFV during the operational phase of the Project;

●

Requiring soft-start during impact pile driving and ramp-up during the use

of high-resolution geophysical (HRG) marine site characterization survey equipment;
●

Requiring various vessel strike avoidance measures;

●

Requiring various measures during fisheries monitoring surveys, such as

removing gear from the water if marine mammals are considered at-risk or are interacting
with gear;
●

Requiring regular and situational reporting including, but not limited to,

information regarding activities occurring, marine mammal observations and acoustic
detections, and sound field verification monitoring results; and
●

Requiring monitoring of the North Atlantic right whale sighting networks,

Channel 16, and PAM data, as well as reporting any sightings to the NMFS or sighting
network.
Through adaptive management, as described in the provisions established in these
regulations, NMFS Office of Protected Resources may modify (e.g., delete, revise, or add
to) the existing mitigation, monitoring, or reporting measures summarized above and
required by the LOA.
NMFS must withdraw or suspend an LOA issued under these regulations, after
notice and opportunity for public comment, if it finds the methods of taking or the
mitigation, monitoring, or reporting measures are not being substantially complied with
or the authorized take is having, or may have, more than a negligible impact on the
concerned species or stock (16 U.S.C. 1371(a)(5)(B); 50 CFR 216.106(e)). Additionally,
failure to comply with the requirements of the LOA may result in civil monetary
penalties and knowing violations may result in criminal penalties (16 U.S.C. 1375; 50
CFR 216.106(g)).
Fixing America’s Surface Transportation Act (FAST-41)
This project is covered under title 41 of the Fixing America’s Surface
Transportation Act, or “FAST-41.” FAST-41 includes a suite of provisions designed to
expedite the environmental review for covered infrastructure projects, including
enhanced interagency coordination as well as milestone tracking on the public-facing

Permitting Dashboard. FAST-41 also places a 2-year limitations period on any judicial
claim that challenges the validity of a Federal agency decision to issue or deny an
authorization for a FAST-41 covered project (42 U.S.C. 4370m-6(a)(1)(A)).
The Project is listed on the Permitting Dashboard, where milestones and
schedules related to the environmental review and permitting for the Project can be found
at https://www.permits.performance.gov/permitting-project/new-england-wind.
Summary of Request
On December 1, 2021, the original applicant, Park City Wind, a limited liability
company registered in the State of Delaware and wholly owned subsidiary of Avangrid
submitted a request for the promulgation of regulations and issuance of an associated 5year LOA to take, by harassment only, marine mammals incidental to construction
activities associated with implementation of the New England Wind Project (hereafter
“Project”) offshore of Massachusetts in the BOEM Lease Area OCS-A 0534 and the
possible use of the SW portion of Lease Area OCS-A 0501. The request was for the
incidental, but not intentional, taking of a small number of 39 marine mammal species by
Level B harassment (for all species or stocks) and by Level A harassment (for 19 species
or stocks). Park City Wind did not request, and NMFS neither expects nor would allow
under this rule, take by serious injury or mortality to occur for any marine mammal
species or stock incidental to the specified activities.
In response to our questions and comments, and following extensive information
exchange between Park City Wind and NMFS, the applicant submitted a final revised
application on July 13, 2022. NMFS deemed it adequate and complete on July 20, 2022.
This final application is available on NMFS’ website at
https://www.fisheries.noaa.gov/protected-resource-regulations.
On August 22, 2022, NMFS published a notice of receipt (NOR) of the adequate
and complete application in the Federal Register (87 FR 51345), requesting public

comments and information during a 30-day public comment period. During the NOR
public comment period, NMFS received comment letters from one private citizen and
one non-governmental organization (ALLCO Renewable Energy Limited). NMFS
reviewed all submitted material and took the material into consideration during the
drafting of the proposed rule.
In January 2023 and again in March 2023, Park City Wind submitted memos to
NMFS detailing updates and changes to their ITA application (“Update Application”).
These memos updated the density models using the 2022 Roberts et al. density models,
project foundation installation and potential UXO/MEC detonation schedules, vibratory
pile driving (i.e., vibratory setting of piles) assessment, and mitigation of drilling activity.
In addition, the applicant detailed development of their fisheries monitoring program and
associated mitigation measures. In a May 2023 memo, Park City Wind submitted
corrected take estimate amounts for foundation installation activities and total take
requested across all activities. These updates were reflected in the proposed rule. These
memos are available on the NMFS website at
https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llcconstruction-new-england-wind-offshore-wind.
On June 8, 2023, NMFS published a proposed rule for the Project in the Federal
Register (88 FR 37606). In the proposed rule, NMFS synthesized all of the information
provided by the applicant, all best available scientific information and literature relevant
to the proposed project, made preliminary small numbers and negligible impact
determinations, and outlined, in detail, proposed mitigation designed to effect the least
practicable adverse impacts on marine mammal species and stocks, as well as proposed
monitoring and reporting measures. The public comment period on the proposed rule was
open for 30 days from June 8, 2023 through July 10, 2023. A summary of public
comments received during this 30-day period are described in the Comments and

Responses section. The public comments are available to be viewed on the Federal eRulemaking Portal at https://www.regulations.gov.
In January 2024, Park City Wind submitted a final draft of the new modeling and
associated acoustic ranges, exposure estimates, and take estimates. Within these memos,
the applicant revised the model(s) used and model assumptions for foundation installation
activities and updated the acoustic ranges, exposure ranges, exposure estimates, take
estimates, and amount of requested take as a result. The model changes are detailed in the
Modeling and Take Estimates section in this final rule. NMFS accepted the updated
modeling and has reflected the changes to the distance to thresholds, exposure estimates,
and take estimates within the final rule. A description of these changes can be found
below in the Modeling and Take Estimates section. This January 2024 Application
Update is on NMFS website at https://www.fisheries.noaa.gov/action/incidental-takeauthorization-park-city-wind-llc-construction-new-england-wind-offshore-wind.
On May 6, 2024, Park City Wind notified NMFS that it had requested that BOEM
segregate a portion of lease area OCS-A-0534, which would then be assigned to another
subsidiary of Avangrid, Commonwealth Wind, LLC, as lease area OCS-A 0561. Park
City Wind requested to NMFS that the incidental take regulation (ITR) governing take of
marine mammals incidental to activities associated with both phases of the Project and
the associated LOA (if issued by NMFS) be issued to Park City Wind’s parent company,
Avangrid, a limited liability company registered in the State of Oregon, who would
oversee phase 1 (constructed and operated by Park City Wind) and phase 2 (constructed
and operated by Commonwealth Wind) of the New England Wind Project. The lease
segregation, completed by BOEM on May 15, 2024, did not alter the geographic location
or size of the area in which the project would be built, nor did the applicant request any
changes to the construction schedule, planned activities, or take. In short, no substantive
changes to the Project were requested. As a result, where appropriate, Avangrid, owner of

Park City Wind, has henceforth been incorporated as the applicant or LOA Holder
throughout this final rule.
NMFS previously issued one Incidental Harassment Authorization (IHA) to Park
City Wind for the taking of small numbers of marine mammals incidental to marine site
characterization surveys, using HRG of the Project’s phase 1 (Park City Wind) in the
BOEM Lease Area OCS-A 0534 (87 FR 44087, July 7, 2022); phase 2 was not part of
this authorization (Commonwealth Wind). However, no work occurred under this initial
IHA and Park City Wind requested a reissuance of the IHA with new effective dates.
NMFS reissued the IHA (88 FR 88892, December 26, 2023) with the new effective dates
of March 1, 2024, through February 28, 2025. NMFS has also previously issued an IHA
to Avangrid, owner of Park City Wind, LLC, to take small numbers of marine mammals
incidental to HRG surveys in BOEM Lease Area (OCS-A 0508) off the coasts of North
Carolina and Virginia (84 FR 31032, June 28, 2019). To date, Park City Wind and
Avangrid have complied with all IHA requirements (e.g., mitigation, monitoring, and
reporting). Applicable monitoring results may be found in the Estimated Take of
Marine Mammals section. If available, the full monitoring reports can be found on
NMFS’ website at https://www.fisheries.noaa.gov/national/marine-mammalprotection/incidental-take-authorizations-other-energy-activities-renewable.
On August 1, 2022, NMFS announced proposed changes to the existing North
Atlantic right whale vessel speed regulations (87 FR 46921, August 1, 2022) to further
reduce the likelihood of mortalities and serious injuries to endangered right whales from
vessel collisions, which are a leading cause of the species' decline and a primary factor in
an ongoing Unusual Mortality Event (UME). Should a final vessel speed rule be issued
and become effective during the effective period of this ITR—or any other MMPA
incidental take authorization (ITA)—the authorization holder will be required to comply
with any and all applicable requirements contained within the final rule. Specifically,

where measures in any final vessel speed rule are more protective or restrictive than those
in this or any other MMPA authorization, authorization holders will be required to
comply with the requirements of the rule. Alternatively, where measures in this or any
other MMPA authorization are more restrictive or protective than those in any final
vessel speed rule, the measures in the MMPA authorization will remain in place. The
responsibility to comply with the applicable requirements of any vessel speed rule will
become effective immediately upon the effective date of any final vessel speed rule and,
when notice is published on the effective date, NMFS will also notify Avangrid if the
measures in the speed rule were to supersede any of the measures in the MMPA
authorization such that they were no longer required.
Description of the Specified Activity
Overview
Avangrid plans to construct and operate two offshore wind projects within OCSA 0534 and OCS-A 0561: Park City Wind (phase 1, 0534) and Commonwealth Wind
(phase 2, 0561) (collectively called New England Wind; hereinafter referred to as
“Project”). The Project will occupy all of Lease Area OCS-A 0534, OCS-A 0561, and
potentially a portion of Lease Area OCS-A 0501 in the event that Vineyard Wind 1 does
not develop spare or extra positions included in Lease Area OCS-A 0501. If Vineyard
Wind 1 does not develop spare or extra positions in Lease Area OCS-A 0501, those
positions would be assigned to Lease Area OCS-A 0534.
The Project will consist of several different types of permanent offshore
infrastructure, including wind turbine generators (WTGs) and associated foundations,
electrical service platforms (ESPs) and their foundations, inter-array cables, offshore
export cables, and scour protection. Specifically, activities to construct the Project
include the installation of 41-62 WTGs and 1-2 ESPs in phase 1 by impact and vibratory
pile driving and, in the event of an obstruction, drilling. Phase 2 depends upon the final

footprint of phase 1. Phase 2 is expected to include the installation of 64-88 WTGs and 13 ESP positions by impact and vibratory pile driving and, in the event of an obstruction,
drilling. In total, up to 129 WTGs and 2-5 ESPs may be constructed at a maximum of 130
positions (2 positions may potentially have co-located ESPs (i.e., two foundations
installed at one grid position), resulting in 132 foundations). Additional activities will
include cable installation, site preparation activities (e.g., dredging), HRG surveys, the
potential detonations of up to 10 UXO/MEC, and conducting several types of fishery and
ecological monitoring surveys. Multiple vessels will transit within the Project Area and
between ports and the wind farm to perform the work and transport crew, supplies, and
materials. All offshore cables will connect to onshore export cables, substations, and grid
connections in Barnstable County, Massachusetts. Marine mammals exposed to elevated
noise levels during pile driving, drilling, UXO/MEC detonations, or site characterization
surveys may be taken by Level A harassment and/or Level B harassment, depending on
the specified activity. A detailed description of the construction project is provided in the
proposed rule as published in the Federal Register (88 FR 37606, June 8, 2023).
Dates and Duration
Avangrid anticipates activities resulting in harassment to marine mammals
occurring throughout all 5 years of the final rule (table 1). Offshore Project activities
are expected to begin in March 2025, after issuance of the 5-year LOA, and continue
through March 2030. Avangrid anticipates the following construction schedule over the
5-year period. Avangrid has noted that these are the best and conservative estimates for
activity durations, but that the schedule may shift due to weather, mechanical, or other
related delays. Additional information on dates and activity-specific durations can be
found in the proposed rule and are not repeated here.
Table 1 – Activity Schedule to Construct and Operate the Project
Project Activity

Expected Timing

Expected Duration

HRG Surveys

Q1 2025 - Q4 2029

Any time of the year, up to 25
days per year

Scour Protection Pre- or PostInstallation

Q1 2025 - Q4 2029

Any time of the year

WTG and ESP Foundation
Installation, Schedule A

Q2 - Q4 2026 and 20271

Up to 8 months per year

WTG and ESP Foundation
Installation, Schedule B

Q2 - Q4 2026, 2027, and
Up to 8 months per year

Horizontal Directional
Drilling at Cable Landfall
Sites

Q4 2025 - Q2 2026

Up to 150 days

UXO/MEC Detonations

Q2 - Q4 2025 and 2026

Up to 6 days in 2025 and 4
days in 2026. No more than
10 days total

Inter-array Cable Installation

Q3 - Q4 2026 and Q2 2027 Q2 2028

Phase 1: 5 months
Phase 2: 10 months

Export Cable Installation and
Termination

Q2 2026 - Q2 2028

Phase 1: 8-9 months
Phase 2: 13-17 months

Fishery Monitoring Surveys

Q1 2025 - Q4 2029

Any time of year

Turbine Operation

Initial turbines operational 2027, all turbines operational by
Note: Project activities are anticipated to start no earlier than Q1 2025. Q1= January
through March; Q2= April through June; Q3= July through September; Q4= October
through December. The Project is divided into two phases: Park City Wind (phase 1) and
Commonwealth Wind (phase 2).
1 – Foundation installation pile driving and drilling would be limited to May 1December 31, annually; however, impact pile driving and drilling in December will not
be planned but may occur due to unforeseen circumstances (e.g., unanticipated
extended weather delays, unexpected technical difficulties) and with NMFS approval.
Vibratory pile driving (e.g., vibratory setting of piles) must not occur December 1-May
31, annually.
Specified Geographical Region
A detailed description of the Specified Geographical Region, identified as the
Mid-Atlantic Bight, is provided in the proposed rule (88 FR 37606, June 8, 2023). Since
the proposed rule was published, no changes have been made to the Specified
Geographical Region. This final rule provides clarity on the boundaries of the MidAtlantic Bight, which spans from Cape Hatteras, North Carolina to Cape Cod,

Massachusetts and extends into the western Atlantic to the 100-m isobath. All of
Avangrid’s specified activities (i.e., pile driving and drilling of WTG and ESP
foundations; number of possible UXO/MEC detonations (n=10); placement of scour
protection; trenching, laying, and burial activities associated with the installation of the
export cable route and inter-array cables; HRG site characterization surveys; and WTG
operation) are concentrated in the Lease Area and cable corridor offshore Massachusetts.
Avangrid would also concentrate vessel use within this area; however, some limited
vessel movement may occur outside this area.

Figure 1 – Lease Area and Cable Corridor

Comments and Responses
NMFS published a proposed rule in the Federal Register on June 8, 2023 (88 FR
37606) for a 30-day public comment period. The proposed rule described, in detail, the
specified activities, the specified geographical region of the specified activities, the

marine mammal species that may be affected by these activities, and the anticipated
effects on marine mammals. In the proposed rule, we requested that interested persons
submit relevant information, suggestions, and comments on Park City Wind’s (now
Avangrid’s) request for the promulgation of regulations and issuance of an associated
LOA described therein, our estimated take analyses, the preliminary determinations, and
the proposed regulations.
NMFS received 41 comment submissions, including comments from the Marine
Mammal Commission (Commission), several non-governmental organizations, and
private citizens, all of which are available for review on https://www.regulations.gov.
Some of these comments were out-of-scope or not applicable to the Project (e.g., general
opposition to or support of offshore wind projects, concerns for other species outside
NMFS’ jurisdiction) and are not described herein or discussed further. Non-governmental
organizations included: Long Island Commercial Fishing Association, Responsible
Offshore Development Alliance, and Green Oceans. These letters, and the Commission’s,
contained substantive information that NMFS considered in this final rule, including
comments related to the estimated take analysis, final determinations, and final
mitigation, monitoring, and reporting requirements. A summary of comments are
described below, along with NMFS’ responses.
Modeling and Take Estimates
Comment 1: The Commission has stated that, due to uncertainty in how NMFS
will be addressing their previously submitted comments for other final offshore wind
rulemakings, they are not providing “an exhaustive letter regarding similar issues” for the
proposed action. They have stated that, in lieu of this, they incorporate by reference all
previously submitted comment letters for past proposed rules (i.e., Empire Wind,
Dominion Energy Virginia, Sunrise Wind, Revolution Wind, Ocean Wind 1, South Fork
Wind) and that NMFS should specifically review these previously submitted letters (e.g.,

Sunrise Wind (88 FR 8996, February 10, 2023), Revolution Wind (87 FR 79072,
December 23, 2022), and Ocean Wind 1 (87 FR 64868, October 26, 2022) and
incorporate, where applicable, relevant information in the context of the Project. They
specifically noted that these general concerns could include “underestimated numbers of
Level A and B harassment takes (including failing to round up to group size), incomplete
SFV measurement requirements, insufficient mitigation and monitoring measures, errors
and omissions in the preamble to and the proposed rule, and the general issue of quality
control and quality assurance in NMFS's preparation of proposed incidental take
authorizations.”
Response: NMFS acknowledges the receipt of a comment letter on the proposed
Project by the Commission, as well as receipt of comment letters from the Commission
for the other referenced proposed projects. We appreciate that, in the past, the
Commission has provided very specific and detailed comments and suggestions on
NMFS' actions, as a collaborative effort to improve both the ITAs themselves as well as
the conservation benefits for NMFS' trust species. Because the Commission did not
provide specific comments on the proposed rule for the Project, we cannot address any
specific concerns. However, we can address general themes of concern raised in previous
letters, and, inasmuch as another specific comment is applicable here, we refer the
Commission back to our previous responses.
Overall, the Commission's letters raised concerns over concern underestimated
Level A and B harassment zones and numbers of takes, incomplete SFV measurement
requirements, insufficient mitigation and monitoring measures, errors and omissions in
the proposed rule and its preamble, and the general issue of quality control and quality
assurance in NMFS’s preparation of proposed ITAs. With respect to mitigation,
monitoring and reporting requirements, we have thoroughly addressed the Commission's
previous concerns and have updated final rules, including this one, accordingly. Lastly,

any “omissions” and “general issues of quality control and quality assurance” from one
action are less likely to be present in another action as updates are carried through across
actions (although NMFS does not agree that every example previously raised by the
Commission was, in fact, an error).
Comment 2: Commenters recommend NMFS re-estimate and authorize Level A
harassment takes based on modeling results for the worst-case scenario rather than
presuming an arbitrary 80- or 100-percent reduction for mitigation efficacy and/or a 10dB sound attenuation for impact pile driving, re-estimate and authorize Level B
harassment takes based on more conservative assumptions for the pile-driving scenarios
that could occur (including only one monopile or fewer than four pin piles installed per
day), re-estimate the various mortality, Level A harassment, and Level B harassment
zones and numbers of takes based on 0 dB of sound attenuation for UXO/MEC
detonations and authorize Level A and B harassment takes, including behavior takes, that
could result from UXO/MEC detonations, and increase any Level A or B harassment
takes to mean group size (including updates that reflect the results of more recent marine
mammal surveys in the Rhode Island-Massachusetts WEA). Other commenters had
similar comments. Commenter(s) also suggested that the numbers of takes, particularly
with respect to the North Atlantic right whale, rely on mitigation methods that remain
unproven.
Response: NMFS disagrees that our analysis should carry forward take estimates
based on the worst-case scenario that assumes no reduction of impacts results from the
mitigation and notes that the commenter did not present any data supporting their
recommendation. As described in the proposed rule, this final rule reasonably assumes
that the mitigation efforts will be effective at reducing the potential for Level A
harassment calculated in the density-based models. The models do not account for
mitigation (except with respect to assuming attenuation and seasonal restrictions) and,

therefore, it is reasonable to assume the model overestimates Level A harassment.
Further, while the scientific literature documents marine mammals are likely to avoid
loud noises such as pile driving (e.g., Brandt et al., 2016, Nowack et al., 2004),
avoidance was not quantitatively considered in the take estimates (although NMFS
reasonably predicts this natural behavior will further reduce the potential for Level A
harassment).
In the proposed rule, NMFS described the best available science, which supports
the assumption that at least 10 dB of attenuation can be reliably achieved using noise
attenuation systems such as a double bubble curtain. The commenter did not provide
reason for why they believe this was an overestimate nor did they suggest an alternative
amount of attenuation NMFS should consider other than zero attenuation. Other
commenters expressed similar support stating that bubble curtains are not effective for
low-frequency cetaceans. NMFS agrees that attenuation levels vary by frequency band
and that bubble curtains attenuate higher frequency sounds more effectively; however,
NMFS disagrees that lower frequency bands, which are important to consider when
evaluating impacts, are not attenuated at all. The data from Bellmann (2021), shows that
for both single and double bubble curtains, more than 10 dB of attenuation was achieved
for bands as low as 32 Hz. And while it is true that performance diminishes significantly
at lower frequencies (< 32 Hz), those bands also contain significantly less pile driving
sound and is 16+ dB outside the most susceptible frequency range for low-frequency
cetaceans.
NMFS recognizes that the key to effective mitigation is the ability to detect
marine mammals to trigger such mitigation. Avangrid is required to undertake extensive
monitoring to maximize marine mammal detection effectiveness. The reduction to the
density-based take estimate appropriately reflects and acknowledges the monitoring

efforts, including the placement of three PSOs on the pile driving platform and dedicated
PSOs vessel(s) and PAM.
NMFS agrees that there is potential for behavioral disturbance from a single
detonation per day and disagrees that “behavior takes” were omitted and have not been
accounted for. However, the behavioral threshold for underwater detonations identified
by the Commission (5 dB less than the temporary threshold shift (TTS) is only applicable
to multiple detonations per day. NMFS is not aware of evidence to support the assertion
that animals will have behavioral responses that would qualify as take to temporally and
spatially isolated explosions at received levels below the TTS threshold. Accordingly, the
current take estimate framework allows for the consideration of behavioral disturbance
resulting from single explosions specifically if they are exposed above the TTS threshold,
as opposed to the 5-dB lower threshold for behavioral disturbance from multiple
detonations. We acknowledge in our analysis that individuals exposed above the TTS
threshold may also be harassed by direct behavioral, disruption and those potential
impacts are considered in the negligible impact determination. The distances to
harassment thresholds have not changed from the application and proposed rule and are
presented in this final rule. Take estimates did not change as a result of including this
additional information.
Comment 3: Commenter(s) claimed that NMFS thresholds are outdated, primarily
because scientific literature demonstrates examples where behavioral disturbances have
been documented where received levels are lower than 160 dB. Moreover, the commenter
suggested that estimating the extent of Level B take from impact driving using the 160dB
(impulsive) threshold is flawed because an animal may be exposed to several hours of
pile driving per day which should be considered continuous and that, although impulsive
at the source, the sound from impact driving may be received as a continuous source at a
distance. Commenter(s) stated that vessel noise is not included in the effects and that it

should be included in calculations for harassment zones (as a continuous noise source)
and as a source of take. For these reasons, commenter(s) suggested the proposed rule
underestimates the takes by Level B harassment and “zones of impact”; thus NMFS’
small numbers and negligible impact determination is flawed.
Response: For the reasons described below, NMFS disagrees that the 160-dB
threshold for behavioral harassment is not supported by the best available science and
that the small numbers and negligible impact determinations are flawed based on the use
of this threshold in the take estimate analysis. The potential for behavioral response to an
anthropogenic source can be highly variable and context-specific (Ellison et al., 2012).
While NMFS acknowledges the potential for Level B harassment at exposures to
received levels below 160 dB rms, it should also be acknowledged that not every animal
exposed to received levels above 160 dB rms will respond in ways constituting
behavioral harassment. There are a variety of studies indicating that contextual variables
play a very important role in response to anthropogenic noise, and the severity of effects
are not necessarily linear when compared to a received level (RL). Several studies (e.g.,
Nowacek et al., 2004 and Kastelein et al., 2012 and 2015) showed there were behavioral
responses to sources below the 160 dB threshold but also acknowledged the importance
of context in these responses. For example, Nowacek et al. (2004) reported the behavior
of five out of six North Atlantic right whales was disrupted at RLs of only 133–148 dB re
1 μPa (returning to normal behavior within minutes) when exposed to an alert signal.
However, the authors also reported that none of the whales responded to noise from
transiting vessels or playbacks of ship noise even though the RLs were at least as loud
and contained similar frequencies to those of the alert signal. The authors state that a
possible explanation for whales responding to the alert signal and not responding to
vessel noise is due to the whales having been habituated to vessel noise while the alert
signal was a novel sound. In addition, the authors noted differences between the

characteristics of the vessel noise and alert signal, which may also have played a part in
the differences in responses to the two noise types. Therefore, it was concluded that the
signal itself, as opposed to the RL, was responsible for the response. DeRuiter et al.
(2012) also indicate that variability of responses to acoustic stimuli depends not only on
the species receiving the sound and the sound source, but also on the social, behavioral,
or environmental contexts of exposure. Finally, behavioral responses depend on many
contextual factors, including range to source, RL above background noise, novelty of the
signal, and differences in behavioral state (Ellison et al., 2012, Gong et al., 2014).
Similarly, Kastelein et al. (2015) examined behavioral responses of a harbor porpoise to
sonar signals in a quiet pool but stated behavioral responses of harbor porpoises at sea
would vary with context such as social situation, sound propagation, and background
noise levels.
NMFS uses 160 dB (rms) as the received sound pressure level for estimating the
onset of Level B behavioral harassment takes for impulsive/intermittent sound sources,
and this is currently considered the best available science while acknowledging that the
160 dBrms step-function approach is a simplistic approach. While it may be true because
of reverberation that impulsive pile driving strikes may "stretch" as their sound travels
through the environment, we do not classify these sounds as continuous, like drilling and
vibratory pile driving. NMFS' behavioral harassment thresholds consider instantaneous
exposure to noise and are based on a received level. These thresholds do not account for
duration of exposure, as our PTS onset thresholds do. Thus, whether an individual was
exposed to a few pile driving strikes or exposed for several hours of pile driving, the 160dB threshold would still apply. While it is correct that in practice it works as a stepfunction (i.e., animals exposed to received levels above the threshold are considered to be
“taken” and those exposed to levels below the threshold are not), it is in fact intended as a
sort of mid-point of likely behavioral responses, which are extremely complex depending

on many factors including species, noise source, individual experience, and behavioral
context. What this means is that, conceptually, the function recognizes that some animals
exposed to levels below the threshold will in fact react in ways that appropriately
considered take while others that are exposed to levels above the threshold will not. Use
of the 160-dB threshold allows for a simplistic quantitative estimate of take while we can
qualitatively address the variation in responses across different received levels in our
discussion and analysis.
Overall, we reiterate the lack of scientific consensus regarding what criteria might
be more appropriate. Defining sound levels that disrupt behavioral patterns is difficult
because responses depend on the context in which the animal receives the sound,
including an animal's behavioral mode when it hears sounds (e.g., feeding, resting, or
migrating), prior experience, and biological factors (e.g., age and sex). Other contextual
factors, such as signal characteristics, distance from the source, and signal to noise ratio,
may also help determine response to a given received level of sound. Therefore, levels at
which responses occur are not necessarily consistent and can be difficult to predict
(Southall et al., 2007; Ellison et al., 2012; Southall et al., 2021). For example, Gomez et
al. (2016) reported that RL was not an appropriate indicator of behavioral response.
Further, the seminal reviews presented by Southall et al. (2007), Gomez et al. (2016), and
Southall et al. (2021) did not suggest any specific new criteria due to lack of convergence
in the data. Undertaking a process to derive defensible exposure-response relationships,
as suggested by Tyack and Thomas (2019), is complex. The recent systematic review by
Gomez et al. (2016) was unable to derive criteria expressing these types of exposureresponse relationships based on currently available data.
NMFS acknowledges that there may be methods of assessing likely behavioral
responses to acoustic stimuli that better capture the variation and context-dependency of
those responses than the simple 160 dB step-function used here; there is no agreement on

what that method should be or how more complicated methods may be implemented by
applicants. NMFS is committed to continuing its work in developing updated guidance
with regard to acoustic thresholds but pending additional consideration and process, is
reliant upon an established threshold that is reasonably reflective of best available
science.
NMFS disagrees that vessel noise would result in take and, therefore, be
necessary to include in the take calculations in this final rule. Vessels produce lowfrequency noise, primarily through propeller cavitation, with main energy in the 5–300
hertz (Hz) frequency range. Source levels range from about 140 to 195 decibels (dB)
referenced to 1 (re 1) μPa (micropascal) at 1 m (National Research Council (NRC), 2003;
Hildebrand, 2009), depending on factors such as vessel type, load, and speed, and vessel
hull and propeller design. Studies of vessel noise show that it appears to increase
background noise levels in the 71–224 Hz range by 10–13 dB (Hatch et al., 2012;
McKenna et al., 2012; Rolland et al., 2012). As discussed in the Negligible Impact
Analysis and Determination section (specifically the Auditory Masking or
Communication Impairment section) of both the proposed and final rule, the level of
masking that could occur from the specified activities will have a negligible impact on
marine mammals, including North Atlantic right whales. Inherent in the concept of
masking is the fact that the potential for the effect is only present during the times that the
animal and the sound source are in close enough proximity for the effect to occur. In
addition, this time period would need to coincide with a time that the animal was utilizing
sounds at the masked frequency). As our analysis (both quantitative and qualitative
components) indicates, because of the relative movement of whales and vessels, as well
as the stationary nature of a majority of the activities, we do not expect these exposures
with the potential for masking to be of a long duration within a given day. Further,
because of the relatively low density of North Atlantic right whales during months when

most of project activities would be occurring (i.e., May through November in most
cases), and the relatively large area over which the vessels will travel and where the
activities will occur, we do not expect any individual North Atlantic right whales to be
exposed to potentially masking levels from these surveys for more than a few days in a
year. Furthermore, as many of the activities are occurring in clusters and specific areas
rather than sporadically dispersed in the Project Area (i.e., foundation installation all
occurs in the same general area, nearshore cable installation activities occur in relatively
similar and nearby areas), animals are likely to temporarily avoid these locations during
periods where activities are occurring but are expected to return once activities have
ceased.
As noted above, any masking effects of the project’s activities are expected to be
limited in duration, if present. For HRG surveys, given the likelihood of significantly
reduced received levels beyond short distances from the transiting survey vessel, the
short duration of potential exposure, the lower likelihood of extensive additional
contributors to background noise offshore and within these short exposure periods, and
the fact that the frequency of HRG signals are primarily above those used in social
communication or for detection of other important clues, we believe that the incremental
addition of the survey vessel is unlikely to result in more than minor and short-term
masking effects. For pile driving and drilling, and especially foundation installation,
masking effects are more likely given the larger zones and longer durations, and animals
that approach the source could experience temporary masking of some lower frequency
cues. However, any such effects would be localized to the areas around these stationary
activities, which means that whales transiting through the area could adjust their transit
away from the construction location and return once the activity has completed. As
described in the “Potential Effects of the Activities on Marine Mammals” section of the
proposed rule, NMFS acknowledges the noise contributions of vessels to the soundscape

and the potential for larger vessels such as commercial shipping vessels, especially, to
mask mysticete communication. For the activity as a whole, including the operation of
supporting vessels for Avangrid's activities, any masking that might potentially occur
would likely be incurred by the same animals predicted to be exposed above the
behavioral harassment threshold, and thereby accounted for in the analysis. NMFS notes
that the commenter did not provide additional scientific information for NMFS to
consider to support its concern.
Comment 4: Commenter(s) recommended that NMFS should consider the best
available data regarding North Atlantic right whale abundance in the project area, as well
as the most comprehensive models for estimating marine mammal take and developing
robust mitigation measures.
Response: The MMPA and its implementing regulations require that ITRs be
established based on the best scientific evidence available. NMFS generally considers the
information in the most recent U.S. Atlantic and Gulf of Mexico Marine Mammal Stock
Assessments Report (SAR; Hayes et al., 2023) to be the best scientific evidence available
for a particular marine mammal stock because of the MMPA's rigorous SAR procedural
requirements, which includes peer review by a statutorily established Scientific Review
Group. Since publication of the proposed rule, NMFS has released the draft 2023 Stock
Assessment Report indicating the North Atlantic right whale population abundance is
estimated as 340 individuals based on sighting data through December 31, 2021 (89 FR
5495, January 29, 2024). NMFS has used the best scientific evidence available in the
analysis of this final rule. This new stock abundance estimate, which is based on the
analysis from Pace et al. (2017) and subsequent refinements found in Pace (2021),
provides the best scientific evidence available, and in this case, the most recent estimate,
including improvements to NMFS's right whale abundance model. NMFS notes this
estimate aligns with the 2022 North Atlantic Right Whale Report Card (Pettis et al.,

2022) estimate (also 340) based on sighting data through August 2022 but, as described
above, the SARs are peer reviewed by other scientific review groups prior to being
finalized and published and the Report Card is published independently by Consortium
members without undertaking this peer review process. Based on this, NMFS has
considered all relevant information regarding North Atlantic right whale, including the
information cited by the commenters. However, NMFS has relied on the draft 2023 SAR
in this final rule as it reflects the best scientific evidence available.
We further note that this change in abundance estimate does not change the
estimated take of North Atlantic right whales or authorized take numbers, nor affect our
ability to make the required findings under the MMPA for Avangrid's construction
activities.
NMFS evaluates the models used by applicants to support take estimates to ensure
that they are methodologically sound and incorporate the best science available. NMFS
also requires use of the Roberts et al. (2016, 2023) density data and SARs abundance
estimates for all species, both of which represent the best scientific evidence available
regarding marine mammal occurrence.
Comment 5: Commenter(s) stated that Level A harassment in the form of a
Permanent Threshold Shift (PTS) would result in deafness and lead to mortality. It was
also asserted that Level B harassment in the form of a TTS is temporary deafness which
could result in an increased risk of vessel strike. Lastly, that NMFS has refused to
acknowledge the lack of available data on low frequency cetacean hearing or potential
behavioral impacts from noise on low frequency cetacean species.
Response: Neither the proposed rule or this final rule allow mortality or serious
injury of marine mammals to be authorized. The best scientific evidence available
indicates that the anticipated impacts from the specified activities potentially include
avoidance, cessation of foraging or communication, TTS and PTS, stress, masking, etc.

(as described in the Effects of the Specified Activities on Marine Mammals and their
Habitat section in the proposed rule). NMFS defines a threshold shift as a change, usually
an increase, in the threshold of audibility at a specified frequency or portion of an
individual's hearing range above a previously established reference level expressed in
decibels (NMFS, 2018). Threshold shifts can be permanent (PTS), in which case there is
an irreversible increase in the threshold of audibility at a specified frequency or portion of
an individual's hearing range or temporary, in which there is reversible increase in the
threshold of audibility at a specified frequency or portion of an individual's hearing range
and the animal's hearing threshold would fully recover over time (Southall et al., 2019a).
When PTS occurs, there can be physical damage to the sound receptors in the ear ( i.e.,
tissue damage) whereas TTS represents primarily tissue fatigue and is reversible
(Henderson et al., 2008). In addition, other investigators have suggested that TTS is
within the normal bounds of physiological variability and tolerance and does not
represent physical injury (e.g., Ward, 1997; Southall et al., 2019a). Therefore, NMFS
does not consider TTS to constitute auditory injury or deafness as it is a temporary form
of hearing impairment. Repeated sound exposure that leads to TTS could cause PTS. For
this project, as stated in the proposed rule, no more than a small degree of PTS is
expected to be associated with any of the incurred Level A harassment, given it is
unlikely that animals would stay in the close vicinity of a source for a duration long
enough to produce more than a small degree of PTS. PTS would consist of minor
degradation of hearing capabilities occurring predominantly at frequencies one-half to
one octave above the frequency of the energy produced by pile driving or instantaneous
UXO/MEC detonation (i.e., the low-frequency region below 2 kHz) (Cody and
Johnstone, 1981; McFadden, 1986; Finneran, 2015), not severe hearing impairment. If
hearing impairment occurs from either impact pile driving or UXO/MEC detonation, it is
most likely that the affected animal would lose a few decibels in its hearing sensitivity,

which in most cases is not likely to meaningfully affect its ability to forage and
communicate with conspecifics.
As stated in the proposed rule, NMFS acknowledges that there is limited data on
threshold shifts in marine mammals. Relationships between TTS and PTS thresholds
have not been studied in marine mammals, and there is no PTS data for cetaceans.
However, such relationships are assumed to be similar to those in humans and other
terrestrial mammals. Noise exposure can result in either a permanent shift in hearing
thresholds from baseline (PTS; a 40 dB threshold shift approximates a PTS onset; e.g.,
Kryter et al., 1966; Miller, 1974; Henderson et al., 2008) or a temporary, recoverable
shift in hearing that returns to baseline (a 6 dB threshold shift approximates a TTS onset;
e.g., Southall et al., 2019). Based on data from terrestrial mammals, a precautionary
assumption is that the PTS thresholds, expressed in the unweighted peak sound pressure
level metric (PK), for impulsive sounds (such as impact pile driving pulses) are at least 6
dB higher than the TTS thresholds and the weighted PTS cumulative sound exposure
level thresholds are 15 (impulsive sound) to 20 (non-impulsive sounds) dB higher than
TTS cumulative sound exposure level thresholds (Southall et al., 2019a). Given the
higher level of sound or longer exposure duration necessary to cause PTS as compared
with TTS, PTS is less likely to occur as a result of these activities, but it is possible and a
small amount has been proposed for authorization for several species. For more detailed
information on PTS and TTS, please see the Hearing Threshold Shift and Negligible
Impact Determination sections of the proposed rule.
NMFS disagrees that the potential effects to species as a result of the project’s
specified activities would result in increased risk of vessel strikes. Please see our
response to Comment 8 for more details on the vessel strike avoidance requirements
required by this final rule.

Comment 6: A commenter suggested that NMFS’ low-frequency cetacean
weighting function is inaccurate because it applies a 2-pole High-pass filter set at 200 Hz,
while Southall et al. (2007) suggested moving the high-pass filter down to 7Hz. The
commenter was also concerned that applying any weighting function underestimates the
potential impacts on marine mammals because they claim applying a weighting function
assumes that when hearing is less sensitive at the outer limits of the hearing range, the
effects to the animal (potential for adverse impact) will be insignificant or non-existent
unless inordinately loud. They also claimed that there is no empirical evidence that
NMFS’ weighting curve aligns with mysticetes infrasonic hearing. Further, they assert
signal kurtosis was not accounted for in NMFS analysis and should be included in any
predictive impact models. Commenter(s) also state that the spreading model is inadequate
for modeling noise levels as it does not account for reflection off the water’s surface or
from other sources.
Response: The marine mammal weighting functions in NMFS’ 2018 Revised
Technical Guidance do not contain any filters. Furthermore, the Revised Technical
Guidance provides generalized hearing ranges for marine mammal species, where the
low-frequency cetacean lower bounds of the hearing range start at 7 kHz. These
weighting functions are meant to reflect the hearing groups’ susceptibility to noiseinduced hearing loss and are based on audiogram data, as well as TTS data. Furthermore,
for impulsive sources, there are peak sound pressure level criteria that are unweighted.
Thus, impacts of noise on hearing will not be underestimated. For low-frequency
cetaceans, since direct measurements of hearing ability are lacking, weighting functions
are based on a multitude of information, including anatomical studies and modeling
(Houser et al., 2001; Parks et al., 2007; Tubelli et al., 2012; Cranford and Krysl 2015);
vocalizations (see reviews in Richardson et al., 1995; Wartzok and Ketten, 1999; Au and
Hastings, 2008); taxonomy; and behavioral responses to sound (Dahlheim and Ljungblad,

1990; see review in Reichmuth, 2007). Finally, kurtosis is an additional metric to
determine if a sound is impulsive versus non-impulsive (i.e., kurtosis is a measure of
the “peakedness” of a noise waveform, with the impulsive components (Qiu et al., 2020).
As described in the proposed rule and NMFS’ Technical Guidance (NMFS, 2018),
NMFS applies different thresholds in an impact analysis for impulsive and non-impulsive
sources. Impact pile driving is categorized as an impulsive sound. Thus, while kurtosis
was not assessed directly, whether a sound is impulsive or non-impulsive is inherently
considered in our analyses when assessing the potential for PTS (i.e., deciding which
acoustic thresholds are appropriate based on sound source characteristics that include a
source's impulsiveness). Therefore, kurtosis (the impulsivity of a sound source) is
accounted for in NMFS analysis.
Potential impacts to marine mammal nervous systems through exposure to sound
were discussed in the proposed rule in the Potential Effects of Underwater Sound on
Marine Mammals section. NMFS assumes that the reference to “injury-causing” SPL by
the commenter is the potential for a permanent threshold shift (PTS).
NMFS disagrees that the spreading model is inadequate. The degree to which
underwater sound propagates away from a sound source is dependent on a variety of
factors, which notably includes the frequency and directivity of the source, water depth
(or bathymetry), the reflective or absorptive nature of the seabed, and other factors.
Spherical spreading occurs in a perfectly unobstructed (free-field) environment not
limited by depth or water surface, resulting in a 6-dB reduction in sound level for each
doubling of distance from the source (20 x log[range]). Spherical spreading can be
thought of as a ‘direct path’ model, as all sound in the water column is assumed to have
arrived via a direct path from the source. Cylindrical spreading occurs in an environment
in which sound propagation is bounded by the water surface and sea bottom, resulting in
a reduction of 3 dB in sound level for each doubling of distance from the source (10 x

log[range]). Both cylindrical spreading and the often used ‘practical spreading’ model are
multi-path models, in that they account for sound which may consist of both direct paths
and paths consisting of reflections from the seabed and the sea surface.
As described in the proposed rule, the area of water ensonified at or above the
RMS 160-dB threshold was calculated using a simple model of sound propagation loss,
which accounts for the loss of sound energy over increasing range. Our use of the
spherical spreading model, is a reasonable approximation over the relatively short ranges
involved. Even in conditions where cylindrical spreading (where propagation loss = 10 x
log [range]; such that there would be a 3-dB reduction in sound level for each doubling of
distance from the source) may be appropriate (e.g., non-homogenous conditions where
sound may be trapped between the surface and bottom), this effect does not begin at the
source. Rather, spreading is typically more or less spherical from the source out to some
distance, and then may transition to cylindrical (Richardson et al., 1995). Further, for
these types of surveys, NMFS has determined that spherical spreading is a reasonable
assumption even in relatively shallow waters, as the reflected energy from the seafloor
will be much weaker than the more dominant, direct path energy. This is a result of the
typically high-frequency and often downward directed nature of most HRG sources.
Similar arguments, related to the validity of spherical spreading in shallow water for
some HRG sources, have been made in literature (Ruppel et al., 2022), and NMFS has
relied on this approach for past ITAs with similar equipment, locations, and depths.
NMFS' User Spreadsheet tool assumes a “safe distance” methodology for mobile sources
where propagation loss is spherical spreading (20LogR)
(https://media.fisheries.noaa.gov/2020-12/User_Manual%20_DEC_2020_508.pdf?null),
and NMFS calculator tool for estimating isopleths to Level B harassment thresholds also
incorporates the use of spherical spreading. NMFS has determined that spherical

spreading is the most appropriate form of propagation loss for these surveys and
represents the best scientific information available.
Comment 7: Commenter(s) stated that auditory injury can occur below the PTS
threshold and could occur below the TTS threshold. Further, that noise levels that did not
manifest in PTS soon after an exposure event could cause irreversible neural damage in
mammals after repeated or cumulative exposure. They also stated that the threshold for
tissue injury has been found to occur at lower threshold than the threshold for TTS onset
(Houser, 2021). NMFS’ nearly singular focus on PTS distance (distance from activity at
which partial or full permanent deafness will be induced in the whale) as the only
indicator of “take” (premature death or reproductive failure affecting the population) is
not reasonable. NMFS has no empirically derived direct measure of thresholds for PTS
harm, but rather PTS is modeled from (limited) TTS data. NMFS is inappropriately
defining “harm” to low-Frequency baleen whales as NMFS does not have any
empirically-determined benchmark for what is the injury-causing sound pressure level
(SPL) against which to measure the proposed activities.
Response: NMFS’s TTS thresholds represent an onset of noise-induced hearing
loss (i.e., 6 dB threshold shift) and are considered the minimum threshold shift clearly
larger than any day-to-day or session-to-session variation in a subject’s normal hearing
ability (Schlundt et al., 2000; Finneran et al., 2000; Finneran et al., 2002). There have
been no indications that in marine mammals TTS occurs below our current thresholds.
Furthermore, as Houser 2021 indicates “There are relatively few studies demonstrating
that TTS can be associated with the destruction of tissue. To date, relevant studies have
only been performed in terrestrial laboratory animals.” Studies on terrestrial mammals
indicating neuropathy from noise exposure are associated with threshold shifts of 40 to
50 dB. Finally, PTS is defined as a threshold shift that does not fully recover back to
baseline levels. It should not be assumed that an animal with PTS is deaf.

As stated in the proposed rule and reiterated here, there are no PTS data available
for cetaceans and only one instance of PTS being induced in older harbor seals
(Reichmuth et al., 2019). However, available TTS data (of mid-frequency hearing
specialists exposed to mid- or high-frequency sounds (Southall et al., 2007; NMFS, 2018;
Southall et al., 2019)) suggest that most threshold shifts occur in the frequency range of
the source up to one octave higher than the source. We would anticipate a similar
frequency range affected for PTS. Further, no more than a small degree of PTS is
expected to be associated with any of the incurred Level A harassment, given it is
unlikely that animals would stay in the close vicinity of a source for a duration long
enough to produce more than a small degree of PTS. More information on PTS and TTSPTS shift can be found in the “Negligible Impact Analysis and Determination” and the
“Potential Effects of Underwater Sound on Marine Mammals” sections in the proposed
rule. Furthermore, NMFS also relies on our behavioral harassment thresholds to assess
potential effects occurring below levels associated with PTS and TTS. For information on
the 160 dB threshold (onset of Level B behavioral harassment), please see our response
to Comment 3. For more information related to PTS, please see our response to Comment
5.
Mitigation
Comment 8: Commenter(s) requested NMFS add to or modify the vessel strike
avoidance mitigation measures contained within the proposed rule. Recommendations
included “strengthening vessel speed restrictions”, and if weather or other conditions
limit the range of observation, shutdown zones (including for transiting vessels) will be
initiated keeping 500 meters (m) away from North Atlantic right whale. A commenter
also incorrectly claimed that vessel speed restrictions are not fully mandated or enforced
for offshore wind vessels.

Response: NMFS acknowledges that vessel strikes pose a risk to all large whales,
including North Atlantic right whales and the proposed rule and this final rule require
multiple mitigation measures to effect the least practicable adverse impact from vessels
on marine mammals. These measures are more restrictive than other industrial,
commercial, military, and recreational vessels. All transiting vessels (regardless of speed
or size) are required to have a dedicated visual observer watching for marine mammals.
In the event a marine mammal is observed under certain circumstances, the vessel must
slow to 10 kn or less or, if within separation zones (which are encoded in regulation (62
FR 6729, March 17, 1997) or follow marine mammal viewing guidelines), turn away
from and slow engines to neutral. In any SMA, DMA, Slow Zone (the latter two of which
are currently voluntary for other vessels), Avangrid must operate vessels at 10 kn or less.
Further, between November 1 and April 30, all vessels, regardless of size, in the specified
geographical region must operate at 10 kn or less (11.5 mph). NMFS has determined it is
impracticable for all vessels to travel 10 kn or less at all times and is not necessary to
achieve the least practicable adverse impact given the mitigation discussed above. As
described above, in many cases, there are no alternatives to the 10 kn or less speed
restriction. However, NMFS has determined that when whales are less likely to be in the
area and visual and acoustic monitoring is conducted, Avangrid vessels could travel at
over 10 kn. NMFS has determined that the monitoring required, including both direct
marine mammal monitoring and situational awareness monitoring and reporting, are
sufficient to allow Avangrid vessels to travel at speeds greater than 10 kn when vessel
strike risk is lowest when not subjected to the previously described restrictions.
In this final rule, NMFS is requiring that all vessels associated with Avangrid's
activities must be equipped with a properly installed, operational Automatic
Identification System (AIS) device and Avangrid must report all Maritime Mobile
Service Identify (MMSI) numbers to NMFS Office of Protected Resources, thus

facilitating monitoring of vessel speeds. In addition, NMFS maintains an Enforcement
Hotline for members of the public to report violations of vessel speed restrictions. NMFS
is not requiring PSOs to be onboard every transiting vessel as it is impracticable due to
potential limited space on the vessels. However, as described in the proposed rule and
carried forward in this final rule, Avangrid must have dedicated visual observers onboard
all vessels with no other concurrent duties. The dedicated visual observer may be a PSO
or a trained crew member.
Avangrid provided information pertaining to the types and number of vessels
necessary to construct the project. They are also required to submit a Marine Mammal
Vessel Strike Avoidance Plan, which must include, but is not limited to, more detail on
ports used and means by which they would abide by the extensive measures outlined
here. While NMFS acknowledges that vessel strikes can result in injury or mortality, we
have analyzed the potential for vessel strike resulting from Avangrid's activity and, in
consideration of the required mitigation measures specific to vessel strike avoidance
included in the final rule NMFS has determined that the potential for vessel strike is so
low as to be discountable and thus, no vessel strikes are expected or authorized to occur.
These measures also ensure the least practicable adverse impact on species or stocks and
their habitat.
Comment 9: Commenter(s) asserted an independent review of mitigation
measures should be required due to limitations associated with visual monitoring and
PAM.
Response: The MMPA does not require an independent review of mitigation
measures. In contrast, it does require notice and opportunity for public comment (16
U.S.C. 1371(a)(5)(A)(i)). The public comment period is a means by which the public
(i.e., independent reviewers) are able to provide NMFS with mitigation measure

recommendations supported by scientific evidence that NMFS takes into consideration
when finalizing the rulemaking.
Comment 10: Commenter(s) recommended clarification should be included in the
LOA that explicitly states if a shutdown would be initiated as a result of weather or other
conditions that limit the range of observation.
Response: The comment refers to a 500-m shutdown zone for North Atlantic right
whales; therefore, NMFS assumes the recommendation is referring to HRG surveys, a
low impact activity. As described in the proposed rule and this final rule, PSOs are
required to monitor the shutdown zone during operations. During periods of low
visibility, alternative monitoring technology (i.e., infrared or thermal cameras) must be
used to monitor these zones. This final rule clarifies that when the shutdown zones
become obscured for brief periods (no more than 30 minutes) due to inclement weather,
survey operations may continue (i.e., no shutdown is required) so long as no marine
mammals have been detected. Further, the shutdown requirement is waived for certain
genera of small delphids. As noted above, take of marine mammals from HRG surveys is
limited overall, take by Level B harassment only is expected to occur only within a small
area in close proximity to the vessel, and no Level A harassment is expected to result
from exposure to the surveys even in the absence of mitigation. There is a low likelihood
that short periods of obscured visibility might potentially coincide with a marine mammal
entering the shutdown zone, and a shutdown not occurring. While such an event may
result in a higher level exposure than would occur if the shutdown happened, such an
exposure would still not be expected to result in a Level A take and would be brief and
not change the number of takes or our evaluation of their likely effects, which again, are
expected to be comparatively minor. Additionally, the frequent delay and/or cessation of
HRG surveys creates operational challenges and impracticalities for applicants.

Altogether, the required measures affect the least practicable adverse impact on the
affected species.
Comment 11: Commenter(s) recommended that NMFS require mitigation
measures that meet the least practicable adverse impact standard (e.g., impacts of
underwater noise be minimized to the fullest extent feasible) coupled with a robust
monitoring and reporting program to ensure compliance.
Response: As described in both the proposed rule and this final rule, NMFS has
included requirements for mitigation measures that effect the least practicable adverse
impact on marine mammal species or stocks and their habitat, as required under the
MMPA (16 U.S.C. 1371(a)(5)(A)(i)(II). As they relate to underwater noise, the
mitigation measures include sound attenuation methods that successfully (evidenced by
required sound field verification measurements) reduce real-world noise levels produced
by impact pile driving, vibratory pile driving, and drilling of foundation installation to, at
a minimum, the levels modeled assuming 10 dB of attenuation. NMFS clarifies that,
because no unattenuated piles may be driven, there is no way to confirm a 10-dB
reduction; rather, in situ SFV measurements will be conducted to ensure that sound levels
are at or below those modeled assuming a 10-dB reduction. In addition to the SFV
requirements in the proposed rule, consistent with the Biological Opinion (BiOp), we
added to this final rule the requirement that Avangrid must conduct “Abbreviated SFV”
monitoring (consisting of a single acoustic recorder placed at an appropriate distance
from the pile) on all foundation installations for which the complete SFV monitoring (i.e.,
“Thorough SFV”), as required in the proposed rule, is not carried out. NMFS is requiring
that these SFV results must be included in the weekly reports. Any indications that
distances to the Level A harassment and Level B harassment thresholds for whales are
exceeded must be addressed by Avangrid, including an explanation of factors that

contributed to the exceedance and corrective actions that were taken to avoid exceedance
on subsequent piles.
NMFS has required numerous monitoring and reporting requirements which
result in a robust compliance program.
Effects Assessment
Comment 12: Several commenters disagreed with NMFS’ negligible impact
determination, particularly for North Atlantic right whale. These comments included
assertions that NMFS did not consider the imperiled population status of North Atlantic
right whale; NMFS did not evaluate the cumulative effects of all projects (such as
offshore wind construction and operational noise, underwater noise, and site
characterization surveys and baseline background levels of ambient noise which result in
stress); NMFS did not meaningfully examine the effects of the loss of communication
space on marine mammals and, further, seems to misapprehend the spatial and temporal
scope of the effects (e.g., masking, disruption to courtship and mating behaviors,
foraging/feeding, and TTS, etc.); that NMFS did not adequately assess the impact of
behavioral disruption on feeding and similar behaviors resulting in decreased body
condition nor the asserted increased risk of mortality from TTS; that any effect to the
small number of breeding females can adversely affect fecundity and imperil the species;
that NMFS has not used the best available science when reaching its NID by using the
160-dB threshold; and that NMFS did not consider whether abandonment of habitat that
was designated with the express purpose of preventing vessel strikes would push the
species further into a vessel traffic corridor, thereby elevating the risk to the species nor
evaluated all the risks to North Atlantic right whale by habitat displacements as sublethal
take has can a measurable effect due to the small population.
Response: NMFS is required to authorize the requested incidental take if it finds
the total incidental take of small numbers of marine mammals by U.S. citizens “while

engaging in that (specified) activity” within a specified geographical region during the 5year period (or less) will have a negligible impact on such species or stock and, where
applicable, will not have an unmitigable adverse impact on the availability of such
species or stock for subsistence uses (16 U.S.C. 1371(a)(5)(A)). Negligible impact is
defined as “an impact resulting from the specified activity that cannot be reasonably
expected to, and is not reasonably likely to, adversely affect the species or stock through
effect on annual rates of recruitment or survival” (50 CFR 216.103). Consistent with the
preamble of NMFS' implementing regulations (54 FR 40338, September 29, 1989), the
impacts from other past and ongoing anthropogenic activities are factored into the
baseline, which is used in the negligible impact analysis. Here, NMFS has factored into
its negligible impact analysis the impacts of other past and ongoing anthropogenic
activities via their impacts on the baseline (e.g., as reflected in the density/distribution
and status of the species, population size and growth rate, and other relevant stressors).
The preamble of NMFS' implementing regulations also addresses cumulative
effects from future, unrelated activities. Such effects are not considered in making the
negligible impact determination under MMPA section 101(a)(5). NMFS considers: (1)
cumulative effects that are reasonably foreseeable when preparing a National
Environmental Policy Act (NEPA) analysis; and (2) reasonably foreseeable cumulative
effects under section 7 of the ESA for ESA-listed species, as appropriate. Accordingly,
NMFS has adopted and reviewed BOEM's EIS and as part of its inter-agency
coordination. This EIS addresses cumulative impacts related to the Project and
substantially similar activities in similar locations. Cumulative impacts regarding the
promulgation of the regulations and issuance of a LOA for construction activities planned
by Avangrid, have been adequately addressed in the adopted EIS that supports NMFS'
determination that this action has been appropriately analyzed under NEPA. Separately,
the cumulative effects of the Project on ESA-listed species, including the North Atlantic

right whale, were analyzed under section 7 of the ESA when NMFS engaged in formal
inter-agency consultation with the NOAA Greater Atlantic Regional Field Office
(GARFO). The BiOp for the Project determined that NMFS' promulgation of the
rulemaking and issuance of an LOA for construction activities, individually and
cumulatively, are likely to adversely affect, but not jeopardize, listed marine mammals.
NMFS disagrees that our negligible impact determination is flawed or not
supported. NMFS fully disclosed the imperiled status of North Atlantic right whales in
the Description of Marine Mammals in the Area of Specified Activity section of the
proposed rule. The proposed rule, as well as this final rule by reference, fully explains the
impacts to North Atlantic right whales is expected to be limited to low-level behavioral
harassment (e.g., temporary avoidance or cessation of foraging). The proposed rule also
described the Potential effects of behavioral disturbance on marine mammal fitness and
that, based on the best available science, behavioral disturbance resulting from the
specified activities is not expected to impact individual animals' health or have effects on
individual animals' survival or reproduction, thus no detrimental impacts at the
population level are anticipated. The commenters do not provide scientific evidence that
suggests otherwise. Specifically, the commenters did not provide evidence that any effect
to a breeding female would result in reduced fecundity.
Commenters suggested NMFS did not meaningfully evaluate loss of
communication space; however, the Effects on Marine Mammals and Their Habitat in the
proposed rule contained an analysis on the impacts of masking both in general and from
the specified activities. NMFS also disagrees that TTS would result in increased risk of
mortality. TTS was fully described in the Potential Effects of Underwater Sound on
Marine Mammals and Potential Effects of Disturbance on Marine Mammal Fitness in the
proposed rule. NMFS does not anticipate nor authorize serious injury or mortality of any
marine mammal species for the specified activities.

NMFS acknowledges that whales may temporarily avoid the area where the
specified activities occur. However, NMFS does not anticipate, based on the best
available science, that whales will abandon their habitat, as suggested by a commenter, or
be displaced in a manner that would result in a higher risk of vessel strike, and the
commenter does not provide evidence that either of these effects should be a reasonably
anticipated outcome of the specified activity. The primary activity that is anticipated to
result in temporary avoidance of the otherwise used habitat is foundation installation pile
driving and drilling. Not only would this activity be limited to times of year when North
Atlantic right whale presence is low, pile driving and drilling would be intermittent, and
only occur for a limited time over the course of 2 or 3 years (depending on schedule
type). Together, these factors further reduce the likelihood that this species would be in
close enough proximity to the activity to engage in avoidance behavior to the degree it
would move into an area of risk (which would be closer to shore) that it could be struck
by another vessel.
For NMFS’ response on the use of the 160-dB threshold, please see our response
to Comment 3.
Comment 13: Commenter(s) questioned the validity of NMFS small numbers
analysis on the basis that the numbers do not account for the cumulative take numbers
from previous, ongoing, or potential projects.
Response: NMFS has provided a reasoned approach to small numbers, as
described in the “Taking Marine Mammals Incidental to Geophysical Surveys Related to
Oil and Gas Activities in the Gulf of Mexico” final rule (86 FR 5322 at 5438, April 19,
2021). Utilizing that approach, NMFS has made the necessary small numbers finding for
all affected species and stocks in this case (see Small Numbers section for more detail).
Neither the MMPA nor our implementing regulations require the small numbers analysis
to consider take from previous, ongoing, or potential projects.

Comment 14: Commenters suggested NMFS failed to account for the cumulative
(or additive) impacts on marine mammal species in the analysis and that NMFS should
evaluate the cumulative impacts of ongoing and future OSW projects rather than
evaluating projects individually, including that NMFS must consider the total number of
takes proposed to be authorized across all wind projects. They suggested that NMFS must
fully consider the discrete effects of each activity and the cumulative effects of the suite
of approved, proposed, and potential activities on marine mammals, including North
Atlantic right whales, and ensure that the cumulative effects are not excessive before
issuing a LOA.
Response: Neither the MMPA nor NMFS' implementing regulations call for
consideration of the take resulting from other specified activities in the negligible impact
analysis. The preamble to NMFS' implementing regulations (54 FR 40338, September
29, 1989) states, in response to comments, that the impacts from other past and ongoing
anthropogenic activities are to be incorporated into the negligible impact analysis via
their impacts on the baseline. Consistent with that direction, NMFS has factored into its
negligible impact analysis the impacts of other past and ongoing anthropogenic activities
via their impacts on the baseline (e.g., as reflected in the density/distribution and status of
the species, population size and growth rate, and other relevant stressors). The 1989 final
rule for the MMPA implementing regulations also addressed public comments regarding
cumulative effects from future, unrelated activities. There, NMFS stated that such effects
are not considered in making findings under section 101(a)(5) concerning negligible
impact. In this case, this ITR, as well as other ITRs currently in effect or proposed within
the specified geographical region are appropriately considered an unrelated activity
relative to the others. The ITRs are unrelated in the sense that they are discrete actions
under section 101(a)(5)(A) issued to discrete applicants. Section 101(a)(5)(A) of the
MMPA requires NMFS to make a determination that the take incidental to a “specified

activity” will have a negligible impact on the affected species or stocks of marine
mammals.
NMFS' implementing regulations require applicants to include in their request a
detailed description of the specified activity or class of activities that can be expected to
result in incidental taking of marine mammals, 50 CFR 216.104(a)(1). Thus, the
“specified activity” for which incidental take coverage is being sought under section
101(a)(5)(A) is generally defined and described by the applicant. Here, Avangrid was the
applicant for the ITR, and we are responding to the specified activity as described in that
application and making the necessary findings on that basis.
Through the response to public comments in the 1989 implementing regulations
(54 FR 40338, September 29, 1989), NMFS also indicated (1) that we would consider
cumulative effects that are reasonably foreseeable when preparing a NEPA analysis and
(2) that reasonably foreseeable cumulative effects would also be considered under section
7 of the ESA for listed species, as appropriate. Accordingly, NMFS has adopted an EIS
written by BOEM and reviewed by NMFS as part of inter-agency coordination. This EIS
addresses cumulative impacts related to the Project and substantially similar activities in
similar locations. Cumulative impacts regarding the promulgation of the regulations and
issuance of a LOA for construction activities, such as those planned by Avangrid, have
been adequately addressed under NEPA in the adopted EIS that supports NMFS'
determination that this action has been appropriately analyzed under NEPA. Separately,
the cumulative effects of the Project on ESA-listed species, including North Atlantic right
whales, was analyzed under section 7 of the ESA when NMFS engaged in formal interagency consultation with GARFO. The BiOp for the Project determined that NMFS'
promulgation of the rulemaking and issuance of a LOA for construction activities
associated with leasing, individually and cumulatively, are likely to adversely affect, but
not jeopardize, listed marine mammals.

Comment 15: Commenter(s) claimed the request for an ITA should be denied
alleging the specified activities kill marine mammals and some commenters suggested
that the ongoing whale UMEs, including the whale deaths occurring in the winter of
2022-2023, are linked with ongoing offshore wind survey work (i.e., HRG surveys). One
commenter claimed the burden of proof is on NMFS to prove, with evidence, that there is
no association between HRG surveys and whale injuries, including “rectified diffusion”,
deaths or otherwise assume that offshore wind activity has contributed to these deaths. A
commenter also asserted that the activities covered by the ITR and associated LOA are
reasonably likely to result in Level A take of North Atlantic right whales that are not
covered by the authorization’s terms.
Response: Neither the proposed rule or this final rule allow mortality or serious
injury of marine mammals to be authorized. The best available science indicates that the
anticipated impacts from the specified activities potentially include avoidance, cessation
of foraging or communication, TTS and PTS, stress, masking, etc. (as described in the
Effects of the Specified Activities on Marine Mammals and their Habitat section in the
proposed rule). NMFS emphasizes that there is no evidence that noise resulting from
offshore wind development-related specified activities would cause marine mammal
strandings, and there is no evidence linking recent large whale mortalities and currently
ongoing offshore wind activities. The commenters offer no such evidence or other
scientific information to substantiate their claim. This point has been well supported by
other agencies, including BOEM and the Marine Mammal Commission (Marine Mammal
Commission Newsletter, Spring 2023).
There is an ongoing UME for humpback whales along the Atlantic coast from
Maine to Florida, which includes animals stranded since 2016, and we provide further
information on the humpback UME in the humpback whale subsection in the Description
of Marine Mammals in the Specified Geographical Region section of this final rule.

Partial or full necropsy examinations were conducted on approximately half of the whales
that recently stranded along the U.S. east coast. Necropsies were not conducted on other
carcasses because they were too decomposed, not brought to land, or stranded on
protected lands (e.g., national and state parks) with limited or no access. Of the whales
examined (roughly 90), about 40 percent had evidence of human interaction, either ship
strike or entanglement. Vessel strikes and entanglement in fishing gear are the greatest
human threats to large whales. The remaining 50 necropsied whales either had an
undetermined cause of death (due to a limited examination or decomposition of the
carcass) or had other causes of death including parasite-caused organ damage and
starvation. The best available science indicates that only Level B harassment, or
disruption of behavioral patterns (e.g., avoidance), may occur as a result of the Project’s
HRG surveys. NMFS emphasizes that there is no credible scientific evidence available
suggesting that mortality and/or serious injury is a potential outcome of the planned
survey activity.
The proposed rule and this final rule state that no take of North Atlantic right
whales by Level A harassment, mortality, or serious injury was requested or proposed for
authorization (see the Estimated Take and Negligible Impact Analysis and Determination
sections), and they are not expected based on the best available science
One commenter cited literature as evidence that seismic surveys in the mid to low
frequency range can injure whales, can cause decompression sickness (the bends) and can
cause rectified diffusion. The Fernandez (2005) paper cited refers to pathology results
from necropsies conducted on beaked whales involved in a mass stranding event in the
Canary Islands following high intensity military training exercises involving numerous
surface warships and several submarines and mid-frequency tactical sonar activities.
NMFS acknowledges the effects of these activities described by the commenter are
known; however, the activities in that paper are not analogous to HRG surveys that

would be conducted by Avangrid to construct the Project, and the information presented
by the commenter is not applicable due to many factors (e.g., pile driving is stationary,
versus the sound sources cited, and HRG surveys utilize a much lower source level).
Comment 16: Commenter(s) recommended NMFS consider the impacts of
structure presence and operations, including those from operational turbine noise on
marine mammals as well as ocean mixing and vibrations on phytoplankton, zooplankton,
and the food chain. Commenter(s) suggested that NMFS did not evaluate the long-term
operational and maintenance impacts of the project on marine mammals and ignored the
best available science demonstrating behavioral impacts to marine mammals from
operational turbines; therefore, NMFS’ small numbers and negligible impact findings are
arbitrary and capricious.
Response: In the proposed rule, NMFS considered the impacts to marine
mammals from operational noise and to their habitat, including prey, from the presence
of structures and operations based on the best available science. In this final rule, NMFS
has supplemented that analysis with new scientific information that has become available
regarding these issues since publishing the proposed rule. This new information does not
change our findings. The commenter did not provide scientific evidence that suggests the
analysis within the proposed rule was unsupported. NMFS has fully evaluated the
potential impacts of both issuing this final rule on marine mammals over the five year
effective period of this rulemaking and the potential impacts from long-term operations
via the BiOp. We refer the reader to the Effects of the Specified Activities on Marine
Mammals and Their Habitat section and the Negligible Impact Determination section
in the proposed and this final rule for further details.
Other
Comment 17: Commenter(s) requested that NMFS consideration of LOAs for
offshore wind developers be applied equitably across industries (e.g., fishing industry)

and that there be a clear threshold for OSW-related takes regionally and across project
phases. In addition, the OSW-industry must be held accountable for incidental takes from
construction and operations separately from the take authorizations for managed
commercial fish stocks. Commenters) also asserted the OSW industry must be held
accountable for their impacts on marine mammals as other industries are (e.g., seasonal
closures on fisheries, marine mammal entanglements).
Response: NMFS considers all ITA requests equally, all takes and regulatory
measures are project-specific. NMFS carefully reviews models and take estimate
methodology to authorize a number of takes, by species and manner of take that is a
likely outcome of the Project. There are several conservative assumptions built into the
models to ensure the number of takes authorized is sufficient based on the description of
the Project. Therefore, takes authorized, being specific to a project, are managed
separately than takes associated with any other project or industry. Avangrid would be
accountable to the measures described in their ITA that were set to achieve “the least
practicable impact on such species or stock and its habitat”. These include mitigation,
monitoring, and reporting measures (e.g., seasonal closures, gear-specific mitigation
measures to avoid entanglements, etc.).
Avangrid would be required to submit frequent reports which would identify the
number of takes applied to the Project. In the unexpected event that Avangrid exceeds the
number of takes authorized for a given species, the MMPA and its implementing
regulations state that NMFS shall withdraw or suspend the LOA issued under these
regulations, after notice and opportunity for public comment, if it finds the methods of
taking or the mitigation, monitoring, or reporting measures are not being substantially
complied with, or the taking allowed is having, or may have, more than a negligible
impact on the species or stock concerned (16 U.S.C. 1371(a)(5)(B); 50 CFR 216.206(e)).
Additionally, failure to comply with the requirements of the LOA may result in civil

monetary penalties and knowing violations may result in criminal penalties (16 U.S.C.
1375; 50 CFR 216.206(g)).
Moreover, as noted previously, fishing impacts, and NMFS assessment of them,
generally center on entanglement in fishing gear, which is a very acute, visible, and
severe impact (i.e., mortality or serious injury). In contrast, the impacts incidental to the
specified activities are primarily acoustic in nature and limited to Level A harassment and
Level B harassment, there is no anticipated or authorized serious injury or mortality that
the fishing industry could theoretically be held accountable for. Any take resulting from
the specified activities would not be associated with take authorizations related to
commercial fisheries. Neither the MMPA nor our implementing regulations require
NMFS to analyze impacts to other industries (e.g., fisheries) from issuance of an ITA
pursuant to section 101(a)(5)(A). We note that the New England Wind Final EIS assesses
the impacts of both BOEM and NMFS’ actions (approving Avangrid’s activities and
authorizing the associated take of marine mammals, respectively) on the human
environment, including to fisheries, and NMFS considered the analysis, as appropriate, in
the final decisions under the MMPA. The impacts of commercial fisheries on marine
mammals and incidental take for said fishing activities are managed separately from
those of non-commercial fishing activities such as offshore wind site characterization
surveys, under MMPA section 118.
Comment 18: Commenter(s) questioned what will happen if incidental take is
exceeded, and the implications of it.
Response: In the unlikely scenario that Avangrid exceeds their authorized take
levels, any further take would be unauthorized and therefore, prohibited under the
MMPA. Avangrid could request additional incidental take of marine mammals from their
specified activities. This would require NMFS to reanalyze its small numbers and

negligible impact determinations and may require reinitiation of the BiOp and
supplemental NEPA analysis depending on the specific facts.
Comment 19: Commenter(s) expressed concern about NMFS' ability to conduct
marine mammal assessment aerial surveys would be detrimentally impacted as a result of
offshore wind structures, thus impacting NMFS’ ability to continue using current
methods to fulfill its mission of precisely and accurately assessing and managing
protected species.
Response: NMFS and BOEM have collaborated to establish the “Federal Survey
Mitigation Strategy for the Northeast U.S. Region” (Hare et al., 2022). This interagency
effort is intended to guide the development and implementation of a program to mitigate
impacts of wind energy development on fisheries surveys. For more information on this
effort, please see https://repository.library.noaa.gov/view/noaa/47925.
Changes from the Proposed to Final Rule
Since the publication of the proposed rule in the Federal Register (88 FR 37606,
June 8, 2023), NMFS has made changes, where appropriate, in response to public
comments and new information provided by Avangrid that are reflected in the regulatory
text and preamble text of this final rule. Specifically, as described above, Avangrid
refined and updated their acoustic modeling for foundation installation activities since the
proposed rule which resulted in changes to the exposure estimates and requested take.
These changes are briefly identified below, with more information included in the
indicated sections of this final rule:
Changes in Information Provided in the Preamble
The information found in the preamble of the proposed rule was based on the best
available information at the time of publication. Since publication of the Proposed Rule,
new information has become available, which has been incorporated into this final rule as
discussed below.

The following change was made throughout the final rule:
At the request of Park City Wind and consent of Avangrid, references to Park
City Wind were replaced with Avangrid and lease number OCS-A 0561 was added,
where appropriate, since lease area OCS-A-0534 was segregated.
The following changes were made to the Purpose and Need for Regulatory
Action section of the preamble to this final rule:
We have added regulatory definitions under Legal Authority for the Final Action
for ease of reference.
The following changes were made to the Summary, Summary of Request and
Description of the Specified Activity sections of the preamble to this final rule:
We have included OCS-A 0561 as Avangrid segregated the OCS-A 0534 lease
area in to two parts: OCS-A 0534 encompasses phase 1 and 0561 encompasses phase 2.
The following changes are reflected in the Description of Marine Mammals in
the Specified Geographical Region section of the preamble to this final rule:
NMFS clarified the boundaries of the specified geographical region such that the
Mid-Atlantic Bight is defined as from Cape Hatteras, North Carolina to Cape Cod,
Massachusetts and extending into the western Atlantic to the 100-m isobath.
Given the release of NMFS’ draft 2023 stock assessment reports (SARs; 89 FR
5495, January 29, 2024), we have updated the population estimate used in the proposed
rule (Hayes et al., 2023) for the North Atlantic right whale (Eubalaena glacialis) from
338 to 340 and the total mortality/serious injury (M/SI) amount from 8.1 to 27.2. This
increase is due to the inclusion of undetected M/SI (whereas 8.1 accounted only for
detected M/SI). As stated in the 2023 draft SARs, the use of the refined methods of Pace
et al. (2021), the estimated annual rate of total mortality of adults and juveniles for the
period 2016–2020 was 27.2, which is over 3 times larger than the 8.1 total derived from
reported mortality and serious injury for the same period.

We have also made updates to the UME summaries for North Atlantic right
whales, humpback whales, minke whales, and phocid seals (pinnipeds).
The following changes are reflected in the Estimated Take, Mitigation, and
Monitoring and Reporting sections the preamble to this final rule:
NMFS received a number of modeling and density updates from the applicant
since the proposed rule, which resulted in associated changes in the size of harassment
zones, take numbers, and mitigation zones. As a result of the updated and refined
modeling, we have updated the methods by which distances to NMFS harassment
thresholds were estimated, the distances to NMFS harassment thresholds, the exposure
estimates based on the updated acoustic modeling, and requested and allowable take
amounts (which, generally speaking, went down as a result of these modeling
refinements). NMFS notes that there were no changes to the number of foundations,
construction schedule, or the assumption of 10 dB of noise attenuation as described in the
proposed rule. The modeling and density changes are briefly listed here and described in
more detail below:
●

Upgraded, more refined take estimation modeling of vibratory pile

driving, to reflect that which was presented in the proposed rule for impact pile driving
(with animats). The revised modeling for vibratory setting of piles (followed by impact
pile driving) replaced the practical spreading loss approach with acoustic modeling; and
exposures for impact pile driving and vibratory setting were updated using animal
movement modeling. This resulted in a notable reduction in exposure ranges and takes by
Level B harassment.
●

Upgraded sound source propagation modeling of the impact pile driving

source, which resulted in little change in take or mitigation zones. The acoustic modeling
was upgraded for impact piling as the previous energy-based parabolic equation model
used to compute the near-field equivalent source before long range propagation was

revised after the proposed rule using JASCO’s Full-Wave PE RAM model (FWRAM) to
compute the near-field equivalent source before the long-range propagation was
computed (also using FWRAM).
●

Upgraded sound source propagation modeling of the drilling activity (in

lieu of 15 logR spreading), which resulted in some minor reductions in take. The acoustic
updated modeling completed for drilling replaced the previous practical spreading loss
approach; exposures were calculated by multiplying the zone of influence (ensonified
area) by density.
●

Improvements to the apportionment of species takes within species guilds

(pilot whales, seals). Updates were made by the applicant to guilded species densities for
vibratory setting followed by impact pile driving, impact pile driving alone, and drilling.
●

An update to the model assumptions for high frequency species (harbor

porpoise). This change reduced the exposure ranges and, subsequently, amount of takes
by harassment.
Following the proposed rule, new modeling was performed for vibratory pile
driving which replaced the previous practical spreading loss approach that defined the
distance to Level B harassment as 50 kilometer (km). For the final rule, acoustic
modeling was completed for vibratory setting of piles followed by impact driving, and
exposures were modeled using animal movement modeling (animat), mirroring the
method described in the proposed rule for impact pile driving. In general, the animat
modeling resulted in the exposure distance to Level B harassment per species decreasing
(most species’ distance to the Level B harassment threshold were around 25 km) and, as
marine mammals densities were applied depending on the exposure range using the 95th
percentile exposure range (ER95%), exposure estimates and takes decreased. Instead of
using a broad 50-km distance for estimating exposure and marine mammal density, such
as was done in the proposed rule, the exposure estimates and take applied the marine

mammal densities at 10 km, 25 km, or 50 km, using the using the next highest density
match to the exposure range. For example, if the ER95% was 8.5 km, the 10 km perimeter
would be used. These revisions to the more refined modeling methods of estimating take
for vibratory pile driving resulted in notable reductions in the Level B take estimates. The
primary model refinement that resulted in the majority of the reduction in exposures and
take in this final rule was from this change in vibratory pile driving modeling.
Following the proposed rule, the modeling methodology for impact pile driving
was refined. In the prior modeling for impact pile driving, an energy-based parabolic
equation (PE) model (JASCO’s MONM) was used to compute the near-field equivalent
source before long range propagation. For the final rule, JASCO’s Full-Wave PE RAM
model (FWRAM) was used to compute the near-field equivalent source before the longrange propagation was computed (also using FWRAM). FWRAM is an improvement
because it calculates full synthetic pressure waveforms (in the time domain), as opposed
to summed energy independent of time. Like MONM, FWRAM is range dependent for
range-varying marine acoustic environments and takes environmental inputs (bathymetry,
water sound speed profile, and seabed geoacoustic profile) into account. FWRAM
computes pressure waveforms via Fourier synthesis of the modeled acoustic transfer
function in closely spaced frequency bands, and employs the array starter method to
accurately model sound propagation from a spatially distributed source (MacGillivray
and Chapman 2012). Ultimately, little difference was observed between the prior sound
fields with near-field equivalents computed using MONM versus the current modeling
with FWRAM, though FWRAM is expected to be a more accurate model.
As part of the above modeling updates to impact pile driving and vibratory pile
driving followed by impact pile driving (MONM to FWRAM modeling), changes
resulted in the exposure ranges for high-frequency cetaceans (harbor porpoise). PE based
models such as MONM and FWRAM are particularly well suited for modeling the

propagation of low frequency sounds, such as impact pile driving, but are limited in terms
of the total and upper frequency range they can accurately and efficiently model (Etter,
2012). For this reason, propagation must be modeled to some upper cut-off frequency.
Beyond this frequency, a linear extrapolation (or roll-off) can be assumed in order to
extend the results to higher frequencies. The slope of this roll-off is based on measured
pile driving data and chosen to be conservative. Selection of a proper upper cut-off
frequency depends on available computational resources, as well as the specific
implementation of the PE method of a particular model (Laws, 2013). Because of this,
and inherent differences of the two modeling methodologies, the cut-off used in the
original modeling for the proposed rule was 300 Hz, while the cut-off in the revised
model is 1,000 Hz. Therefore, the new modeling represents a more accurate
methodology for frequencies between 300 and 1,000 Hz, as full propagation modeling is
performed in this frequency range, rather than an approximate extrapolation (or roll-off).
Both modeling approaches produce the same results at low frequencies where pile driving
sound is dominant, but since the conservatively chosen roll-off started at 300 Hz, there is
more higher frequency energy in the original model than in the revised model. For this
reason, the two approaches produce similar results for low-frequency cetaceans, but the
revised modeling results in substantially different exposure ranges for high-frequency
cetaceans. Following the proposed rule, new modeling was performed for drilling which
replaced the previous practical spreading loss approach that defined the distance to Level
B harassment as 16.6 km. For the final rule, acoustic modeling was completed for drilling
and exposures were calculated by multiplying the zone of influence (ensonified area) by
density. Rather than using practical spreading, sound propagation is modeled using a
combination of an energy-based parabolic equation (PE) model (JASCO’s MONM) at
frequencies up to 1 kHz, and the BELLHOP ray tracing model (Porter and Liu 1994)
from 1 to 25 kHz. BELLHOP is a widely used Gaussian beam ray-trace propagation

model, which incorporates bathymetry, sound speed profiles, and a simplified
representation of the sea bottom; as sub-bottom layers have a negligible influence on the
propagation of acoustic waves with frequencies above 1 kHz. Sound attenuation due to
seawater absorption was included, which can be important for frequencies greater than 5
kHz. The drill was approximated as a point source located at mid-water depth. Further
details regarding MONM are provided below, in the context of pile driving. The density
perimeter was determined using the longest 10-dB attenuated 95th percentile acoustic
range to the behavioral threshold (R95%) for all locations, rounded up to the nearest 5 km,
and then applied around the entire lease area (i.e., 7.1 km rounded up to 10 km). This new
approach is expected to more accurately capture the spatial extent of the sound fields, as
it includes an updated source level (191.6 dB) as well as more sophisticated propagation
modeling which accounts for bathymetry, sound speed profiles, interaction with the
seabed, and seawater absorption. This refinement in the drilling model also resulted in
some minor reductions in exposure and take. Further details can be found in the Modeling
and Take Estimates section.
In order to better reflect available species data specific to the area, we have also
updated the methodology for estimating take for species combined into one guild in the
Roberts et al. density models (harbor seals, grays seals, long-finned pilot whales, and
short-finned pilot whales), by using local abundance data to define how the takes within a
guild should be apportioned by species or stock as opposed to using SAR abundance data
to define how takes should be apportioned with a guild, and subsequently, updated take
by Level B harassment authorized for these species.
As a result of the updated modeling, NMFS has changed (some increases, some
decreases) the minimum visibility zone, clearance zones, and shutdown zones for all
species during foundation installation activities. The clearance and shutdown zones sizes
for each foundation type (i.e., monopile, jacket) are now based on the largest distance to

Level A harassment threshold of all the foundation installation methods (i.e., impact pile
driving, vibratory pile driving, drilling), with a 20 percent increase to the clearance zone.
Avangrid requested, and NMFS has carried forward, zone sizes by the largest foundation
type (i.e., monopile, jacket) and hammer size. Lastly, Avangrid did not request different
zone sizes based on the 12-m monopile versus the 13-m monopile in their January 2024
Application Update as they did prior to the proposed rule. Instead, Avangrid proposed
zone sizes based on the 13-m monopile at 6,000 kJ, though this foundation installation
scenario remains unlikely though possible. NMFS has therefore set the zone sizes as the
largest across all foundation and hammer sizes for each foundation type (monopile,
jacket), regardless if Avangrid choses to install a smaller pile or use a smaller hammer
during real-world foundation installation. However, Avangrid may request modifications
through adaptive management should sound field verification (SFV) demonstrate noise
levels are lower than expected.
As a result of the new modeling, the monopile visual (PSO) and acoustic (PAM)
clearance zone sizes for other baleen whales and sperm whale has decreased from 4,700
m for all pile driving and drilling to 3,300 m (all installation methods); the pile driving
and drilling shutdown zones has similarly decreased from 4,700 m (12-m) and 5,500 m
(13-m) to 2,700 m (all installation methods). The refined modeling for harbor porpoise
decreased the zone sizes from 2,300 m (monopile pile driving and drilling) to 250 m, as
the maximum injury (ER95%) for harbor porpoise is 240 m. The zone sizes for seals
decreased from 1,100 m (monopile impact pile driving) and 1,400 m (monopile vibratory
pile driving or drilling) to 200 m (all monopiles and installation methods) as the
maximum injury (ER95%) for seals was 0 m. The clearance and shutdown zones for small
whales and dolphins remain unchanged (200 m) as the maximum injury (ER95%) is 0 m.
For those species that modeling resulted in less than 200 m Level A harassment distance
to threshold, NMFS has set the minimum clearance and shutdown zone size as 200 m to

ensure the zones are outside the monopile’s noise attenuation system (NAS). This was
also the approach in the proposed rule.
Based on the model changes above, the updated jacket (all pin piles) visual (PSO)
and acoustic (PAM) clearance zone sizes for other baleen whales and sperm whale has
increased from 4,500 m for impact pile driving and 4,700 m for vibratory pile driving and
drilling to 4,900 m (all installation methods); the pile driving and drilling shutdown zones
has decreased from 4,500 m for impact pile driving and 4,700 m for vibratory pile driving
and drilling to 4,100 m (all installation methods). The refined modeling for harbor
porpoise decreased the zone sizes from 1,800 m (impact pile driving) and 2,300 m
(vibratory pile driving and drilling) to 250 m as the maximum injury (ER95%) for harbor
porpoise is 230 m. The zone sizes for seals decreased from 1,400 m (all pile driving and
drilling) to 1,000 m (clearance) and 800 m (shutdown) for all installation methods as the
maximum injury (ER95%) for seals was 790 m. The clearance and shutdown zones for
small whales and dolphins remain unchanged (50 m) as the maximum injury (ER95%) was
0 m. For those species that modeling resulted in less than 50 m Level A harassment
distance to threshold, NMFS has set the minimum clearance and shutdown zone size as
50 m to ensure the zones are outside the jacket’s noise attenuation system (NAS). This
was also the approach in the proposed rule.
NMFS has not changed the North Atlantic right whale shutdown and clearance
zones for visual observations (i.e., any distance), NMFS has set the acoustic clearance
and shutdown zones during foundation activities for North Atlantic right whale to any
acoustic detection within a 12-km acoustic monitoring zone which were previously set to
5,600 m (monopile impact pile driving), 4,500 m (monopile vibratory pile driving and
drilling), and 4,500 m (jacket pile driving and drilling). This final rule also clarifies that
PAM must be conducted before, during, and after foundation installation and UXO/MEC

detonation for North Atlantic right whales but the PAM system should be designed to
detect all other marine mammals to the maximum extent practicable.
We updated the minimum visibility zone based on the new modeling from
Avangrid (largest ER95% distance to Level A harassment for low-frequency cetacean, not
including fin whale), for all species during each foundation installation type then rounded
for PSO clarity. As a result of the new modeling, the final rule sets the minimum
visibility zone for monopiles at 2,100 m (humpback whale, 2,070 m), 3,400 m for jacket
installation (humpback whale, 3,320 m), and 500 m for HRG (unchanged from the
proposed rule). As described in the preamble of the proposed rule (page 405), NMFS
originally set the minimum visibility zone size based on the North Atlantic right whale
ER95% distance to the Level A harassment threshold, assuming 10 dB. NMFS recognizes
that a footnote in table 35 of the proposed rule used incorrect terminology stating that the
minimum visibility zone for North Atlantic right whale would be “any distance” which
contradicted the earlier stated methodology for setting the minimum visibility zone and
would not be practicable. As a result of the updated modeling, the minimum visibility
zone in this final rule decreased, however, it is still larger than the updated North Atlantic
right whale ER95% distance to the Level A harassment threshold, assuming 10 dB. To
align with the BiOp, NMFS has used the largest ER95% distance to Level A harassment
for low-frequency cetacean, not including fin whale, which uses the distance to Level A
harassment for humpback whale which is greater than the ER95% distance to Level A
harassment for North Atlantic right whale (monopile 2,070 m vs 1,620 m; jacket 3,320 m
vs 2,350 m).
We have reduced takes by Level B harassment for Northern bottlenose whale
from 12 to 8 as a result of a typo correction submitted by the applicant in the January
2024 Application Update. The applicant had previously not adjusted the total take request
for this rare species by assuming encounters every other year but instead had

unintentionally summed all annual takes at the time of the proposed rule. The takes by
Level B harassment for Northern bottlenose whale in this final rule have been corrected
based on encounters every other year.
NMFS has re-organized and simplified the monitoring and reporting section to
avoid repeating entirely the requirements provided in the regulatory text. NMFS has
renamed the North Atlantic Right Whale Vessel Strike Avoidance Plan to the Marine
Mammal Vessel Strike Avoidance Plan to more accurately reflect that the plan does not
solely apply to North Atlantic right whales.
In response to commenters’ concerns regarding noise attenuation, we have added
a general requirement that Avangrid must lower noise levels should they exceed those
modeled assuming 10 dB of attenuation. Based on multiple commenters’ concerns
regarding noise attenuation, and as informed by preliminary sound measurements from
South Fork Wind, NMFS has added a requirement that two functional noise attenuation
devices that reduce noise levels to the modeled harassment isopleths, assuming a 10-dB
attenuation, must be used during foundation pile driving. A single bubble curtain alone
will not be allowed for use in mitigation.
In response to commenters’ concerns on vessel activity relating to the Project, all
project vessels must utilize AIS device and must report all MMSI numbers to NMFS
Office of Protected Resources;
This final rule clarifies that the mitigation measure restricting Project vessels from
traveling over 10 kn (5.14 m/s) in the transit corridor, unless Avangrid conducts real-time
acoustic monitoring to detect large whales (including North Atlantic right whales),
applies only when other speed restrictions are not in place.
For foundation installation, NMFS notes that it is difficult to specify a reduction
in energy for any given hammer because of variation across drivers and installation
conditions. Because other industry operators have identified that specific soft-start

procedures, such as those included in the proposed rule, may raise concerns regarding
engineering feasibility and practicability, we have removed the specifics related to the
soft-start procedure identified in the proposed rule (but not the requirement to conduct a
soft-start), allowing for flexibility should the need for adjustments to the specific
procedures arise. However, any alternative protocol would be as protective as the generic
coastal construction soft-start specifications provided in the proposed rule. The final
soft-start methodology will be developed by Avangrid, in consultation with NMFS,
considering final design details including site-specific soil properties and other
considerations.
To align with the BiOp, NMFS has updated the UXO/MEC detonation zones to
be specific to charge weight. The clearance zones, which are visually and acoustically
monitored, were derived based on an approximate proportion of the size of the Level B
harassment (TTS) isopleth then rounded for PSO clarity. The modeled distances to
NMFS harassment thresholds have not changed from the UXO/MEC Acoustic Analysis
Report in the application. The clearance zone sizes are contingent on Avangrid being able
to demonstrate that they can identify charge weights in the field; if they cannot identify
the charge weight sizes in the field then would need to assume the E12 charge weight size
for all detonations and must implement the E12 clearance zone. No minimum visibility
zone is required for UXO/MEC detonation as the entire visual clearance zone must be
clear given the potential for lung and gastrointestinal tract injury.
We updated the process for obtaining NMFS approval for PSO and PAM
Operators and have clarified education, training, and experience necessary to obtain
NMFS’ approval.
To align with the BiOp, we have added a requirement to have at least three active
PSOs on the foundation installation platform (e.g., pile driving/drilling vessel) and any
dedicated PSO vessel (or equivalent coverage) rather than two PSOs, as was originally

described in the proposed rule. Addition of this requirement is based on NMFS'
evaluation of PSO coverage abilities for similar projects in the area (e.g., Sunrise Wind)
and has found that three PSOs (each covering 120 degrees) will improve the reliability of
detection from the PSO platforms (e.g., pile driving/drilling vessel, PSO-dedicated
vessel, etc.). Previously at least four on-duty PSOs were required to actively observe for
marine mammals before, during, and after installation of foundation piles (i.e., monopiles
and pin piles), at least two of those PSOs must be stationed and observing on the pile
driving vessel and at least two PSOs must be stationed on a secondary, PSO-dedicated
vessel. NMFS is now requiring Avangrid to deploy three on-duty PSOs per platform and
vessel instead of two. Alternatively, Avangrid may propose an alternative method other
than three PSOs per platform that provides equal or greater visual monitoring
effectiveness. Similarly, NMFS is now requiring that Avangrid must deploy at least three
on-duty PSOs, instead of two on-duty PSOs, on each observation platform for all
detonations. To align with the BiOp, NMFS is also requiring the use of two PSOdedicated vessels in addition to the PSOs on the foundation installation platform.
NMFS added a requirement that a double big bubble curtain must be placed at a
distance that would avoid damage to the nozzle holes during all UXO/MEC detonations.
NMFS also added a requirement that a pressure transducer must be used during all
UXO/MEC detonations.
Consistent with the BiOp, NMFS added additional details regarding thorough
SFV requirements and added a requirement for Abbreviated SFV (consisting of a single
recorder with a bottom and mid-water column hydrophone). We have also added
requirements that Thorough SFV must be conducted on every pile until measured noise
levels are at or below the modeled noise levels, assuming 10 dB; the minimum number of
foundations previously required to have SFV has increased and now includes
requirements for each construction year; and we have added a requirement that Avangrid

must deploy at least eight hydrophones at four locations (one bottom and one mid-water
column at each location) along an azimuth that is likely to see lowest propagation loss
and two hydrophones (one bottom and one mid-water) at 750 m, 90 degrees from the
primary azimuth during installation of all piles where Thorough SFV monitoring is
required. Lastly, we have clarified that during Thorough SFV, installation of the next
foundation (of the same type/foundation method) may not proceed until Avangrid has
reviewed the initial results from the Thorough SFV and determined that there were no
exceedances of any distances to the identified thresholds based on modeling assuming 10
dB of attenuation.
We have removed the requirements for reviewing data on an annual and biennial
basis for adaptive management and instead will make adaptive management decisions as
frequently as new information warrants it.
Changes in the Regulatory Text
As described above regarding changes made to the preamble, we have made the
following corresponding and additional changes to the regulatory text in response to new
information provided by Avangrid and public comments.
For clarity and consistency, we revised three paragraphs in § 217.320, “Specified
activity and specified geographical region,” of the regulatory text to fully describe the
specified activity, specified geographical region, and requirements imposed on the LOA
Holder (Avangrid) and to clarify that the regulations apply to Avangrid Renewables LLC,
as well as its successors or assigns, and those persons it authorizes or funds to conduct
activities on its behalf. NMFS has also included the addition of OCS-A 0561 as a result
of the OCS-A 0534 lease segregation.
For clarity, we have specified that any measures in §§ 217.324 and 217.325
required during jacket foundation installation are also required for bottom-frame
foundations that utilize pile foundations.

In §§ 217.320, 217.322, 217.323, 217.324, 217.325, 217.326, and 217.327, NMFS
has made minor changes to formatting and wording to more clearly state the
requirements.
In § 217.324(a), NMFS has clarified that any visual observation of marine
mammals, as opposed to only ESA-listed marine mammals, must be communicated to
PSOs and vessel captains.
NMFS has clarified language in § 217.324(a) on what public sources Avangrid
and its personnel must check and how often to stay informed on North Atlantic right
whales detections in the area.
NMFS has added additional clarification on the authority of PSOs and PAM
operators in § 217.324(a) to ensure compliance and proper implementation of the
regulations.
NMFS has specified that any visual or acoustic detection of a North Atlantic right
whale within clearance zones must trigger a delay in commencement of pile driving,
drilling, UXO/MEC detonation, and HRG surveys. NMFS has also updated the
requirement § 217.324(c)(8)(i) by expanding the terminology of “piles installed” to
foundation installation activities, correcting the November 1–December 30 date range to
November 1–December 31, and increasing the monitoring zone from 10 to 12 km.
NMFS has added a requirement that all project vessels must utilize AIS and must
report all MMSI numbers to NMFS Office of Protected Resources.
NMFS has included a requirement for Avangrid to consent to on-site observations
and inspections by Federal personnel during project activities.
NMFS has added a prohibition to interfering with PSO or PAM operator
responsibilities.

NMFS has added a requirement for any large whale sighting to be communicated
to all project-associated vessels, and for a large whale sighting log sheet to be retained for
the vessel captain’s review each day.
In § 217.324(b), NMFS has clarified the minimum separation zone for vessels
when encountering a North Atlantic right whale.
In § 217.324(d), NMFS has added a requirement that Avangrid must notify
NMFS 48 hours before any planned UXO/MEC detonation event unless this 48-hour
notification would create delays to the detonation that would result in imminent risk to
human life or safety. NMFS has also added a requirement that Avangrid may detonate a
maximum of 10 UXO/MECs, of varying sizes but no larger than 1,000 pounds (lbs; 454
kilograms (kg)) charge weight (i.e., E12), over the effective period of this rulemaking and
LOA(s). NMFS has added a requirement that a pressure transducer must be used to
monitor pressure levels during all UXO/MEC detonations.
NMFS has clarified the requirement in § 217.324(b) to specify that this measure
applies to vessels traveling in the specified geographical region. NMFS has also renamed
the North Atlantic Right Whale Vessel Strike Avoidance Plan requirement to the Marine
Mammal Vessel Strike Avoidance Plan to more accurately reflect that the plan does not
solely apply to North Atlantic right whales.
In consideration of commenters’ concerns regarding strengthening mitigation
measures to avoid vessel strike, NMFS has removed the requirement in § 217.324(b)(14)
from the proposed rule for any underway vessel to avoid speed over 10 kn (18.5 km/hour)
or abrupt changes in course direction until an animal is on a path away from the
separation distance. The current requirement in § 217.324(b) requires vessels to steer a
course away from, reduce speed and shift engine to neutral if an animal is within the
separation distance.

NMFS has clarified the requirement in § 217.324(b)(7) from the proposed rule
that a North Atlantic right whale detection triggers a speed restriction for all transiting
vessels within 10 km for a 24-hour period (previously 12-hour period). This was
previously specific to Slow Zones (i.e., Dynamic Management Areas (DMAs) or
acoustically-triggered slow zone), and Seasonal Management Areas (SMAs). NMFS has
also added a requirement that vessels must not travel over 10 kn from November 1
through April 30, annually, within the specified geographical region. This measures also
now includes a sub-measure that states: if vessel(s) are traveling at speeds greater than 10
kn (11.5 mph) (i.e., no speed restrictions are enacted) in the transit corridor (defined as
from a port to the Lease Area or return), in addition to the required dedicated visual
observer, LOA Holder must monitor the transit corridor in real-time with PAM prior to
and during transits. If a North Atlantic right whale is detected via visual observation or
PAM detection within or approaching the transit corridor, all vessels in the transit
corridor must travel at 10 kn (11.5 mph) or less for 24 hours following the detection.
Each subsequent detection must trigger a 24-hour reset. A slowdown in the transit
corridor expires when there has been no further visual or acoustic detection in the transit
corridor in the past 24 hours. The transit corridor must be defined in the Marine Mammal
Vessel Strike Avoidance Plan.
NMFS has clarified PAM boundaries for detections of North Atlantic right whales
that trigger a delay in the commencement of foundation installation and UXO/MEC
detonation.
In response to comments and to align with the BiOp, NMFS has added a
requirement that two functional noise attenuation devices that reduce noise levels to the
modeled harassment isopleths assuming a 10-dB attenuation, must be used during
foundation installation (impact and vibratory pile driving, drilling) and UXO/MEC
detonation.

NMFS has clarified requirements for PAM systems, including a requirement for
the PAM system to be able to detect a vocalization of North Atlantic right whales up to
12 km away in § 217.324(c). In §§ 217.324 and 217.325, NMFS has removed NMFSapproved PAM systems(s) terminology as NMFS approves PAM plans and not PAM
systems.
To align with the BiOp, NMFS has increased the number of on-duty PSOs on the
foundation installation platform and the number of PSO-dedicated vessels to improve the
reliability of marine mammal detection from the platform in § 217.324(c). The minimum
number of PSOs per platform during UXO/MEC detonation has been increased to three
in § 217.324(d).
NMFS added requirements related to conducting and reporting on Thorough and
Abbreviated SFV to align with the BiOp in § 217.324(c)-(d).
NMFS has clarified requirements for clearance zones, shutdown zones,
deactivating acoustic sources when not in use, PSO activity and communication
requirements, and vessel operator communication requirements, applying to HRG
surveys operating sub-bottom profilers (SBPs) in § 217.324(e) to ensure compliance and
proper implementation of the regulations.
NMFS has added a requirement for acoustic source ramp-ups to be scheduled in
order to minimize the time spent with the source activated.
For fishery monitoring surveys in § 217.324(f), NMFS has clarified language on
emptying survey gear, gear deployment timing, trawl tow times and speed, and visual
monitoring efforts.
The following changes are reflected in § 217.325, “Requirements for monitoring
and reporting,” and the associated Monitoring and Reporting section of the preamble to
this final rule:

NMFS has added a requirement for confirmation of all required training to be
documented on a training course log sheet and reported to NMFS before initiating project
activities. A description of the training program must be provided to NMFS at least 60
days prior to the initial training before in-water activities begin. NMFS has added a
requirement that the marine mammal monitoring team must monitor available sources of
information on North Atlantic right whale presence in or near the Project no less than
every 4 hours.
NMFS has clarified PAM operator qualifications as well as PSO and PAM
training requirements in § 217.235 to ensure compliance and proper implementation of
regulations. This additional clarification includes detailed requirements for prior
experience, being independent observers, ability for PAM operators to review and
classify acoustic detections in real-time, PSO marine mammal identification and behavior
training to focus on species specific to the North Western Atlantic Ocean, and PSO and
PAM training to have been completed within the past 5 years and have included a
certificate of course completion. NMFS has specified that Avangrid must submit the
names of PSOs and PAM operators previously approved by NMFS at least 30 days prior
to commencement of the specified activities and 15 days prior to when new PSO/PAM
operators are required after activities have commenced.
NMFS has specified the following additional details in § 217.325(b) to clarify
PSO and PAM operator requirements in order to ensure compliance and proper
implementation of regulations: PSOs must monitor for marine mammals prior to, during,
and following impact pile driving, vibratory pile driving, drilling, UXO/MEC detonation
and HRG surveys that use sub-bottom profilers and monitoring must be done while free
from distractions; all on-duty PSOs and on-duty PAM operator(s) are to remain in realtime contact with the on-duty construction personnel responsible for implementing
mitigations; and the PAM operator must inform the Lead PSO(s) on duty of animal

detections approaching or within applicable ranges of interest to the activity occurring via
the data collection software system.
NMFS added requirements related to conducting and reporting on SFV (Thorough
and Abbreviated) to align with the BiOp in § 217.325(c), (d), and (f).
NMFS added a requirement to § 217.325(c) for a Nighttime Monitoring Plan if
Avangrid intends to request nighttime foundation installation. No nighttime foundation
installation can occur until NMFS reviews and approves the plan.
NMFS clarified requirements for the PAM Plan and Marine Mammal Monitoring
Plan to align with the BiOp in § 217.325(d).
NMFS has clarified the reporting requirements, such as, the format of dates must
be in the MM/DD/YYYY format, location information must be provided in Decimal
Degrees and with the coordinate system information, and which email addresses a report
must be submitted to.
In consideration of public comments with concerns for underestimating takes by
Level A harassment and Level B harassment, NMFS has added a requirement that if at
any time during the Project Avangrid becomes aware of any issue or issues which may
(to any reasonable subject-matter expert, including the persons performing the
measurements and analysis) call into question the validity of any measured Level A
harassment or Level B harassment isopleths to a significant degree, Avangrid must
inform NMFS Office of Protected Resources within one business day of becoming aware
of this issue or before the next pile is driven, whichever comes first.
NMFS has added specific regional contact information for reporting North
Atlantic right whale sightings and stranded, entangled, injured, or dead marine mammals.
NMFS had added a requirement to report observations of any large whale (other
than North Atlantic right whales) to the WhaleAlert app.

Recognizing the extensive, frequent, and situational monitoring data and report
requirements, NMFS clarified the language describing the annual or biennial review of
data to inform adaptive management decisions to indicate that adaptive management
decisions may be made at any time, as new information warrants it.
Description of Marine Mammals in the Geographic Area
As noted in the Changes from the Proposed to Final Rule section, updates have
been made to the abundance estimate for North Atlantic right whales and to the UME
summaries of multiple species. These changes are described in detail in the sections
below and, otherwise, the marine mammal information has not changed since the
proposed rule.
Thirty-eight marine mammal species under NMFS’ jurisdiction have geographic
ranges within the western North Atlantic OCS (Hayes et al., 2023). Sections 3 and 4 of
Park City Wind’s (now Avangrid’s) ITA application summarize available information
regarding status and trends, distribution and habitat preferences, and behavior and life
history of the potentially affected species (Park City Wind, 2022). Additional information
regarding population trends and threats may be found in NMFS’s SARs
(https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammalstock-assessments) and more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS’s website
(https://www.fisheries.noaa.gov/find-species).
Table 2 lists all species and stocks for which take is expected and may be
authorized for this action, and summarizes information related to the population or stock,
including regulatory status under the MMPA and ESA, and provides the potential
biological removal (PBR), where known. PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be removed from a marine
mammal stock while allowing that stock to reach or maintain its optimum sustainable

population (16 U.S.C. 1362(20)). While no mortality is anticipated or may be authorized,
PBR and annual serious injury and mortality from anthropogenic sources are included
here as gross indicators of the status of the species and other threats.
Marine mammal abundance estimates presented in this document represent the
total number of individuals that make up a given stock or the total number estimated
within a particular study or survey area. NMFS’s stock abundance estimates for most
species represent the total estimate of individuals within the geographic area, if known,
that comprises that stock. For some species, this geographic area may extend beyond U.S.
waters. All managed stocks in this region are assessed in NMFS’s U.S. Atlantic and Gulf
of Mexico SARs. All values presented in table 2 are the most recent available at the time
of publication and are available in NMFS’ 2023 draft SARs available online at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marinemammal-stock-assessment-reports.
Table 2 – Marine Mammal Species that May Occur in the Project Area and be
Taken by Harassment

Common
Name

Scientific
Name1

Stock

ESA/MMP
A status;
Strategic
(Y/N)2

Stock
abundance
(CV, Nmin,
most recent
abundance
survey)3

PBR

Total
Annual
M/SI4

Order Artiodactyla – Cetacea – Superfamily Mysticeti (baleen whales)
Family Balaenidae
North
Atlantic
right
whale5

Eubalaena
glacialis

Western
Atlantic

E, D, Y

340 (0,
337, 2021);
356 (346363, 2022)

0.7

27.2

0.8

Family Balaenopteridae (rorquals)

Blue whale

Balaenopte
ra
musculus

Western
North
Atlantic

E, D, Y

UNK
(UNK;
402; 19802008)

Fin whale

Balaenopte
ra physalus

Western
North
Atlantic

Humpback
whale

Megaptera
novaeangli
ae

Gulf of
Maine

Minke
whale

Balaenopte
ra
acutorostra
ta

Canadian
Eastern
Coastal

Sei whale

Balaenopte
ra borealis

Nova
Scotia

E, D, Y

6,802
(0.24;
5,573;
2021)

2.05

-, -, Y

1,396 (0;
1,380;
2016)

12.15

-, -, N

21,968
(0.31;
17,002;
2021)

9.4

E, D, Y

6,292
(1.02;
3,098;
2021)

6.2

0.6

Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
Family Physeteridae
Sperm
whale

Physeter
macroceph
alus

North
Atlantic

5,895
(0.29;
4,639;
2021)

9.28

0.2

-, -, N

9,474
(0.36,
7,080,
2021)

UNK

-, -, N

9,474
(0.36,
7,080,
2021)

UNK

-, -, N

4,670
(0.24,
3,817,
2021)

0.2

-, -, N

2,936
(0.26,
2,374,
2021)

0.2

E, D, Y

Family Kogiidae
Dwarf
sperm
whale

Kogia sima

Western
North
Atlantic

Pygmy
sperm
whale

Kogia
breviceps

Western
North
Atlantic

Family Ziphiidae
Cuvier's
beaked
whale

Ziphius
cavirostris

Western
North
Atlantic

Blainville's Mesoplodo
beaked
n
whale
densirostris

Western
North
Atlantic

Gervais'
beaked
whale

Mesoplodo
n
europaeus

Western
North
Atlantic

Sowerby's
beaked
whale

Mesoplodo
n bidens

Western
North
Atlantic

True's
beaked
whale

Mesoplodo
n mirus

Western
North
Atlantic

Northern
bottlenose
whale6

Hyperoodo
n
ampullatus

Western
North
Atlantic

-, -, N

8,595
(0.24,
7,022,
2021)

0

-, -, N

492 (0.50,
340, 2021)

3.4

-,-,N

4,480
(0.34,
3,391,
2021)

0.2

-, -, N

UNK
(UNK,
UNK,
2016)

UNK

-, -, N

31,506
(0.28,
25,042,
2021)

0

-, -, N

93,233
(0.71,
54,443,
2021)

28

-, -, N

64,587
(0.24,
52,801,
2021)

28

-, -, N

21,778
(0.72,
12,622,
2021)

0

-, -, N

93,100
(0.56;
59,897;
2021)8

1,452

306

5.7

218

Family Delphinidae
Atlantic
spotted
dolphin

Stenella
frontalis

Western
North
Atlantic

Atlantic
white-sided
dolphin

Lagenorhy
nchus
acutus

Western
North
Atlantic

Common
bottlenose
dolphin7

Tursiops
truncatus

Western
North
Atlantic
Offshore

Clymene
dolphin

Stenella
clymene

Western
North
Atlantic

Common
dolphin

Delphinus
delphis

Western
North
Atlantic

LongGlobicepha
finned pilot
la melas
whales

Western
North
Atlantic

-, -, N

39,215
(0.30;
30,627;
2021)

ShortGlobicepha
finned pilot
la
whale8

Western
North
Atlantic

-, -, Y

18,726
(0.33,

macrorhyn
chus

14,292,
2021)

Risso’s
dolphin

Grampus
griseus

Western
North
Atlantic

False killer
whale

Pseudorca
crassidens

Western
North
Atlantic

Fraser's
dolphin9

Lagenodelp
his hosei

Western
North
Atlantic

Killer
whale10

Orcinus
orca

Western
North
Atlantic

Melonheaded
whale11

Peponocep
hala
electra

Western
North
Atlantic

Pantropical
spotted
dolphin

Stenella
attenuata

Western
North
Atlantic

Pygmy
killer
whale12

Feresa
attenuata

Western
North
Atlantic

Roughtoothed
dolphin13

Steno
bredanensi
s

Western
North
Atlantic

Spinner
dolphin

Stenella
longirostris

Western
North
Atlantic

Striped
dolphin

Stenella
coeruleoal
ba

Western
North
Atlantic

-, -, N

44,067
(0.19,
30,662,
2021)

18

-, -, N

1,298
(0.72, 775,
2021)

7.6

-, -, N

UNK
(UNK,
UNK,
2021)

UNK

-, -, N

UNK
(UNK,
UNK,
2016)

UNK

-, -, N

UNK
(UNK,
UNK,
2021)

UNK

-, D, N

2,757
(0.50,
1,856,
2021)

0

-, -, N

UNK
(UNK,
UNK,
2021)

UNK

-, -, N

UNK
(UNK,
UNK,
2021)

undet

-, D, N

3,181
(0.65,
1,930,
2021)

0

-, -, N

48,274
(0.29,
38,040,
2021)

0

Whitebeaked
dolphin

Lagenorhy
nchus
albirostris

Western
North
Atlantic

-, -, N

536,016
(0.31,
415,344,
2016)

4,153

649

-, -, N

27,911
(0.20,
23,624,
2021)

1,512

4,570

-, -, N

61,336
(0.08,
57,637,
2018)

1,729

426,000

178,573

UNK

Family Phocoenidae (porpoises)
Harbor
porpoise

Phocoena
phocoena

Gulf of
Maine/Bay
of Fundy

-, -, N

85,765
(0.53,
56,420,
2021)

Order Carnivora – Superfamily Pinnipedia
Family Phocidae (earless seals)
Halichoeru
s grypus

Western
North
Atlantic

Harbor seal

Phoca
vitulina

Western
North
Atlantic

Harp seal

Pagophilus
grownlandi
cus

Western
North
Atlantic

-, -, N

7.6M
(UNK,
7.1M,
2019)

Hooded
seal15

Cystophora
cristata

Western
North
Atlantic

-, -, N

UNK
(UNK,
UNK, n/a)

Gray seal14

1 – Information on the classification of marine mammal species can be found on the web
page for The Society for Marine Mammalogy's Committee on Taxonomy
(https://marinemammalscience.org/science-and-publications/list-marine-mammalspecies-subspecies; Committee on Taxonomy, 2023)).
2 – ESA status: Endangered (E), Threatened (T) / MMPA status: Depleted (D). A dash (-)
indicates that the species is not listed under the ESA or designated as depleted under the
MMPA. Under the MMPA, a strategic stock is one for which the level of direct humancaused mortality exceeds PBR or which is determined to be declining and likely to be
listed under the ESA within the foreseeable future. Any species or stock listed under the
ESA is automatically designated under the MMPA as depleted and as a strategic stock.
3 – NMFS’ marine mammal stock assessment reports can be found online
at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammalstock-assessments. CV is the coefficient of variation; Nmin is the minimum estimate of
stock abundance.
4 – These values, found in NMFS' SARs, represent annual levels of human-caused
mortality plus serious injury from all sources combined (e.g., commercial fisheries,
vessel strike).
5 – In the proposed rule (87 FR 79072, December 23, 2022), a population estimate of 368
was used which represented the best available science at the time of publication.

However, since the publication of the proposed rule, a new estimate (n=340) was released
in NMFS’ draft 2023 SARs and has been incorporated into this final rule. The current
draft SAR includes an estimated population (Nbest 340) based on sighting history through
December 2021 (89 FR 5495, January 29, 2024). In October 2023, NMFS released a
technical report identifying that the North Atlantic right whale population size based on
sighting history through 2022 was 356 whales, with a 95 percent credible interval ranging
from 346 to 363 (Linden, 2023); Total annual average observed North Atlantic right
whale mortality during the period 2017–2021 was 7.1 animals and annual average
observed fishery mortality was 4.6 animals. Numbers presented in this table (27.2 total
mortality and 17.6 fishery mortality) are 2016–2020 estimated annual means, accounting
for undetected mortality and serious injury.
6 – The total number of northern bottlenose whales off the eastern U.S. coast is unknown.
Present data are insufficient to calculate a minimum population estimate for this species
(89 FR 5495, January 29, 2024).
7 – As noted in the draft 2023 SAR (89 FR 5495, January 29, 2024), abundance estimates
may include sightings of the coastal form.
8 – A key uncertainty exists in the population size estimate for this species based upon
the assumption that the logistic regression model accurately represents the relative
distribution of short-finned vs. long-finned pilot whales (89 FR 5495, January 29, 2024).
9 – The total number of Fraser's dolphins off the eastern U.S coast is unknown. Present
data are insufficient to calculate a minimum population estimate for this stock (89 FR
5495, January 29, 2024).
10 – The total number of killer whales off the eastern U.S coast is unknown. Present data
are insufficient to calculate a minimum population estimate for this species (89 FR 5495,
January 29, 2024).
11 – The population size of this species is unknown as this species was rarely sighted
during surveys. Present data are insufficient to calculate a minimum population estimate
for this stock (89 FR 5495, January 29, 2024).
12 – The total number of pygmy killer whales off the eastern U.S coast is unknown.
Present data are insufficient to calculate a minimum population estimate for this stock (89
FR 5495, January 29, 2024).
13 – The abundance estimate for this species is based upon the average of the 2011 and
2016 abundance estimates. However, uncertainties in the abundance estimate exist due to
the low number of sightings (n=1 in 2011; n=0 in 2016), variance in encounter rates, and
uncertainty in estimation of detection probability (89 FR 5495, January 29, 2024).
14 – NMFS' stock abundance estimate (and associated PBR value) applies to the U.S.
population only. Total stock abundance (including animals in Canada) is approximately
394,311. The annual M/SI value given is for the total stock (89 FR 5495, January 29,
2024).
15 – There is uncertainty in available population estimates due to limited surveys, limited
reproductive data, and uncertainty in stock relationships and harvest statistics (89 FR
5495, January 29, 2024).
In addition to the species listed in table 2, the Florida manatees (Trichechus
manatus; a sub-species of the West Indian manatee) has been previously documented as
an occasional visitor to the Northeast region during summer months (U.S. Fish and
Wildlife Service (USFWS), 2019). However, manatees are managed by the USFWS and
are not considered further in this document.

As described in the proposed rule, the applicant also requested take for beluga
whales (Delphinapterus leucas), however, there is no beluga whale stock designated
under the MMPA along the U.S. Eastern Seaboard as it is a more northerly species;
therefore, they are not considered further in this document. A detailed description of the
species likely to be affected by the Project, including brief introductions to the species
and relevant stocks, information regarding population trends and threats, and information
regarding local occurrence, were provided in the application and the proposed rule (88
FR 37606, June 8, 2023). Other than adjustments to population statistics (e.g., North
Atlantic right whale population abundance) and UME updates, we are not aware of any
changes in the status of the species and stocks listed in table 2; therefore, detailed
descriptions are not provided here. Please refer to the proposed rule for these descriptions
(88 FR 37606, June 8, 2023). Please also refer to NMFS’ website
(https://www.fisheries.noaa.gov/find-species) for generalized species accounts.
Since the publication of the proposed rule, the following updates have occurred to
the below species in regards to general information or their active UMEs.
North Atlantic Right Whale
In January 2024, NMFS released its draft 2023 SARs which updated the
population estimate (Nbest) of North Atlantic right whales to 340 individuals (a decrease
from the population estimate in the proposed rule (n=368) but an increase from the final
2022 SARs (n=338); the annual M/SI value dropped from the final 2022 SAR of 31.2 to
27.2 in the draft 2023 SAR. Beginning in the 2022 SARs, the M/SI for North Atlantic
right whale included the addition of estimated undetected mortality and serious injury,
which had not been previously included in the SAR. The current population estimate is
equal to the North Atlantic Right Whale Consortium’s 2022 Annual Report Card, which
identifies the population estimate as 340 individuals (Pettis et al., 2023).

As described in the proposed rule, elevated North Atlantic right whale mortalities
have occurred since June 7, 2017, along the U.S. and Canadian coast, with the leading
category for the cause of death for this UME determined to be “human interaction,”
specifically from entanglements or vessel strikes. Since publication of the proposed rule,
the number of animals considered part of the UME has increased. As of April 12, 2024,
there have been 39 confirmed mortalities (dead, stranded, or floaters), 1 pending
mortalities, and 34 seriously injured free-swimming whales for a total of 74 whales. The
UME also considers animals with sublethal injury or illness (called “morbidity”; n=52)
bringing the total number of whales in the UME from 74 to 126. More information about
the North Atlantic right whale UME is available online
at: https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closedunusual-mortality-events.
Humpback Whale
Since January 2016, elevated humpback whale mortalities have occurred along
the Atlantic coast from Maine to Florida. This event was declared a UME in April 2017.
Partial or full necropsy examinations have been conducted on approximately half of the
221 known cases (as of May 3, 2024). There has been no update to this UME since the
proposed rule. More information is available at:
https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusualmortality-events.
Since December 1, 2022, the number of humpback strandings along the midAtlantic coast, from North Carolina to New York, has been elevated. In some cases, the
cause of death is not yet known; in others, vessel strike has been deemed the cause of
death. As the humpback whale population has grown, they are seen more often in the
Mid-Atlantic. These whales may be following their prey (small fish) which were
reportedly close to shore in the 2022-2023 winter. Changing distributions of prey impact

larger marine species that depend on them, and result in changing distribution of whales
and other marine life. These prey also attract fish that are targeted by recreational and
commercial fishermen, which increases the number of boats and amount of fishing gear
in these areas. This nearshore movement increases the potential for anthropogenic
interactions, particularly as the increased presence of whales in areas traveled by boats of
all sizes increases the risk of vessel strikes.
Minke Whale
Since January 2017, a UME has been declared based on elevated minke whale
mortalities detected along the Atlantic coast from Maine through South Carolina. As of
May 3, 2024, a total of 168 minke whales have stranded during this UME. Full or partial
necropsy examinations were conducted on more than 60 percent of the whales.
Preliminary findings have shown evidence of human interactions or infectious disease in
several of the whales, but these findings are not consistent across all of the whales
examined, so more research is needed. More information is available at:
https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusualmortality-events.
Phocid Seals
Since June 2022, elevated numbers of harbor seal and gray seal mortalities have
occurred across the southern and central coast of Maine. This event was declared a UME
in July 2022 but closed after the proposed rule. The UME Investigative Team reviewed
necropsy, histopathology, and diagnostic findings. They determined the UME was
attributed to spillover events of the highly pathogenic avian influenza H5N1 virus from
infected wild birds to harbor and gray seals. An ongoing HPAI H5N1 global outbreak in
domestic and wild birds and wild mammals began in 2021. Live seals showed signs of
respiratory and neurological disease including nasal and ocular discharge, coughing,
unresponsiveness, and seizures. Eighteen percent of the stranded seals (33 out of 180)

were tested for avian influenza via polymerase-chain-reaction. A subset of seals were
positive for HPAI H5N1 with preliminary findings confirmed by the United States
Department of Agriculture’s National Veterinary Services Laboratories. Of the 33 seals
tested during the UME period 19 (58 percent) were positive for H5N1 (17 harbor seals; 2
gray seals) and 14 (42 percent) tested negative. Twelve H5N1 positive seals had
histopathology conducted; 11 of those seals had lesions (primarily respiratory and/or
neurologic) suspected or consistent with avian influenza infection. Sequencing of the
H5N1 virus detected in seals suggests the seals were infected from spillover events from
infected wild birds to these seals. While the UME was not occurring in the area of the
Project, the populations affected by the UME were the same as those potentially affected
by the Project. Information on this UME is available online at:
https://www.fisheries.noaa.gov/national/marine-life-distress/active-and-closed-unusualmortality-events.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals underwater,
and exposure to anthropogenic sound can have deleterious effects. To appropriately
assess the potential effects of exposure to sound, it is necessary to understand the
frequency ranges marine mammals are able to hear. Current data indicate that not all
marine mammal species have equal hearing capabilities (e.g., Richardson et al., 1995;
Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. (2007)
recommended that marine mammals be divided into functional hearing groups based on
directly measured or estimated hearing ranges on the basis of available behavioral
response data, audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements of hearing ability
have been successfully completed for mysticetes (i.e., low-frequency cetaceans).
Subsequently, NMFS (2018) described generalized hearing ranges for these marine

mammal hearing groups. Generalized hearing ranges were chosen based on the
approximately 65-dB threshold from the normalized composite audiograms, with the
exception for lower limits for low-frequency cetaceans where the lower bound was
deemed to be biologically implausible and the lower bound from Southall et al. (2007)
retained. Marine mammal hearing groups and their associated hearing ranges are
provided in table 3.
Table 3 -- Marine Mammal Hearing Groups (NMFS, 2018)
Hearing Group
Low-frequency (LF) cetaceans
(baleen whales)

Generalized Hearing Range*
7 Hz to 35 kilohertz (kHz)

Mid-frequency (MF) cetaceans
(dolphins, toothed whales, beaked whales, bottlenose
whales)

150 Hz to 160 kHz

High-frequency (HF) cetaceans
(true porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus cruciger & L.
australis)

275 Hz to 160 kHz

Phocid pinnipeds (PW) (underwater)
(true seals)

50 Hz to 86 kHz

* Represents the generalized hearing range for the entire group as a composite (i.e., all species within the group),
where individual species’ hearing ranges are typically not as broad. Generalized hearing range chosen based on
~65-dB threshold from normalized composite audiogram, with the exception for lower limits for LF cetaceans
(Southall et al., 2007) and PW pinniped (approximation).

The pinniped functional hearing group was modified from Southall et al. (2007)
on the basis of data indicating that phocid species have consistently demonstrated an
extended frequency range of hearing compared to otariids, especially in the higher
frequency range (Hemilä et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 2013).
NMFS notes that in 2019a, Southall et al. recommended new names for hearing
groups that are widely recognized. However, this new hearing group classification does
not change the weighting functions or acoustic thresholds (i.e., the weighting functions
and thresholds in Southall et al. (2019a) are identical to NMFS 2018 Revised Technical

Guidance). When NMFS updates our Technical Guidance, we will be adopting the
updated Southall et al. (2019a) hearing group classification.
Potential Effects of Specified Activities on Marine Mammals and Their Habitat
Exposure to underwater noise and explosive detonations from the Project’s
specified activities have the potential to result in Level A harassment or Level B
harassment of marine mammals in the specified geographical region, but no serious
injury or mortality. The proposed rule (88 FR 37606, June 8, 2023) included a discussion
of the effects of anthropogenic noise on marine mammals and the potential effects of
underwater noise and explosive detonations from the Project’s specified activities on
marine mammals and their habitat. While some new literature regarding marine mammal
distribution and habitat use has been published since publication of the proposed rule
(e.g., Holdman et al., 2023; Meyer-Gutbrod et al., 2023; Van Parijs et al., 2023;
Westwell et al., 2024), there is no new information that NMFS is aware of that changes
the analysis in the proposed rule. We provide a summary of these papers below.
Holdamn et al. (2023) studied harbor porpoise habitats in the Gulf of Maine
(GOM) and Southern New England waters providing baseline data on the occurrence and
foraging activity of porpoises from 2020 to 2022. Harbor porpoises were present yearround in the GOM with peak detections in the summer and fall. The observed seasonal
pattern of harbor porpoise occurrence in this study is consistent with prior information on
the general distribution of the GOM/Bay of Fundy stock (Wingfield et al., 2017; NMFS,
2021). In line with previously reported distribution patterns, harbor porpoise occurrence
in Southern New England was high in fall, winter and spring, but porpoises were largely
absent in the summer. Results from generalized additive models suggest that time of year,
hour of day, lunar illumination, and temperature are significant contributors to harbor
porpoise presence (detection mainly through echolocation clicks) and/or foraging effort.

Meyer-Gutbrod et al. (2023) studied North Atlantic right whale sightings from
1990-2018 to examine patterns in monthly habitat use in 12 high-use areas to broadly
characterize new seasonal habitat-use patterns across the core North Atlantic right whale
range. As North Atlantic right whale foraging habitat selection is driven by complex
spatial and temporal patterns (e.g., prey abundance), abundances of Calanus finmarchicus
(a species of copepod and a component of the zooplankton found in the northern Atlantic
Ocean) and Calanus hyperboreus (species of copepod found in the Arctic Ocean and
northern Atlantic Ocean) were also analyzed for decadal variations in the North Atlantic
right whale foraging habitats. The research found that in comparison to the 2000s, the
1990s and the 2010s were similar in that North Atlantic right whale sightings (i.e.,
Sightings Per Unit Effort (SPUE)) declined in the foraging habitats of the Gulf of Maine
and Scotian Shelf during the seasons when abundance of C. finmarchicus was relatively
low (spring, summer, fall). The drop in sightings is associated with extended duration of
habitat use by North Atlantic right whales in Cape Cod Bay into the late spring and
increased use of Southern New England waters and the Gulf of St. Lawrence in the spring
and summer in the 2010s. Summertime declines in the 2010s for copepod abundances in
the traditional foraging habitat (e.g., Gulf of Maine) indicate that the increased use of the
Gulf of St. Lawrence in more recent years is driven by a decline in prey in traditional
foraging habitats rather than by an increase in prey in the new foraging habitat. Overall,
while some patterns in seasonal habitat use remained consistent across all three decades,
including the winter migration to the Southeast US calving ground and early spring
foraging in Cape Cod Bay, there were notable differences in the seasonality and
persistence of North Atlantic right whales in some foraging habitats across the study
period which indicate that the North Atlantic right whale distribution patterns are
shifting.

Van Parijs et al. (2023), provides 2 years of baseline data on cetacean species’
presence, vessel activity, and ambient sound levels in the southern New England wind
energy area. With eight species/families present in the area for at least 9 months of the
year, this area represents an important habitat for cetaceans. Most species showed
seasonality, with peak daily presence in winter (harbour porpoise, North Atlantic right,
fin, and humpback whales), summer (sperm whales), spring (sei whales), or spring and
fall/autumn (minke whales). Delphinids were continuously present and blue whales
present only in January. The North Atlantic right whale was present year round with high
presence in October through April.
Westell et al. (2024) collected baseline data from 2020 to 2022, with six passive
acoustic recorders deployed in the vicinity of Nantucket Shoals and Cox’s Ledge. Data
were analyzed for sperm whale presence, and demographic composition was assessed
using interclick intervals. Presence varied by site, season, and year. Sperm whales were
detected year-round but the majority (78 percent) of days with acoustic occurrences were
between May and August. Sound propagation tests were conducted at two sites and
predicted detection ranges within 20–40 km indicate that sperm whales were likely in
proximity to the WEA. These results provide a baseline for ongoing sperm whale
presence, especially that of social groups which may be more sensitive to disturbance.
Moreover, new data also supports our inclusion of certain mitigation measures in
the proposed and this final rule. For example, Crowe et al. (2023) discussed the use and
importance of real-time data for detecting North Atlantic right whale. The shift in North
Atlantic right whale habitat use motivated the integration of additional ways to detect the
presence of North Atlantic right whales and passive acoustic detections of right whale
vocalizations reported in near real-time became an increasingly important tool to
supplement visual sightings. The proposed rule did include real-time and daily awareness
measures and sighting communication protocols, NMFS evaluated these measures and

added details for clarity or updated the reporting mechanisms, such as in the case of
sighting an injured North Atlantic right whale. Davis et al. (2023) analyzed North
Atlantic right whale individual upcalls from 2 years of acoustic recordings in southern
New England which showed that North Atlantic right whale were detected at least 1 day
every week throughout both years, with highest North Atlantic right whale presence from
October to April. Within SNE, on average, 95 percent of the time North Atlantic right
whales persisted for 10 days, and recurred again within 11 days. An evaluation of the
time period over which it is most effective to monitor prior to commencing pile driving
activities showed that with 1 h of pre-construction monitoring there was only 4 percent
likelihood of hearing a North Atlantic right whale, compared to 74 percent at 18 h.
Therefore, monitoring for at least 24 h prior to activity will increase the likelihood of
detecting an up-calling North Atlantic right whale.
Since issuance of the proposed rule, a non-peer reviewed report on HRG survey
noise has also been released (Rand et al., 2023). The measured data presented in Rand et
al. (2023) are consistent with our evaluation of sound levels produced by HRG surveys
(i.e., received sound levels at the ranges measured) and vessels and do not change our
assessments of potential impacts. The analysis of those data in the Rand et al. (2023)
report, however, includes methodological issues and therefore does not support all of
their conclusions.
Since the publication of the proposed rule, new scientific information has become
available that provides additional insight into the sound fields produced by turbine
operation (HDR, Inc., 2023; Holme et al., 2023). Recently, Holme et al. (2023) stated
that Tougaard et al. (2020) and Stöber and Thomsen (2021) extrapolated levels for larger
turbines and should be interpreted with caution since both studies relied on data from
smaller turbines (0.45 to 6.15 MW) collected over a variety of environmental conditions.
They demonstrated that the model presented in Tougaard et al. (2020) tends to

overestimate levels (up to approximately 8 dB) measured to those in the field, especially
with measurements closer to the turbine for larger turbines. Holme et al. (2023) measured
operational noise from larger turbines (6.3 and 8.3 MW) associated with three wind farms
in Europe and found no relationship between turbine activity (i.e., power production,
which is proportional to the blade’s revolutions per minute) and noise level. However, it
was noted that this missing relationship may have been masked by the area’s relatively
high ambient noise sound levels. Sound levels (i.e., root-mean-square (RMS)) of a 6.3
MW direct-drive turbine were measured to be 117.3 dB at a distance of 70 m. However,
measurements from 8.3 MW turbines were inconclusive as turbine noise was deemed to
have been largely masked by ambient noise.
In addition, operational turbine measurements from the Coastal Virginia Offshore
Wind pilot pile project indicated that noise levels from two, 7.8 m monopiles WTGs were
higher when compared to Block Island wind farm, likely due to vibrations associated
with the monopiles structure (HDR, Inc., 2023). We note that this updated information
does not change our assessment for impacts of turbine operational sound on marine
mammals. As described in the proposed rule, NMFS will require Avangrid to measure
operational noise levels, however, is not authorizing take incidental to operational noise
from WTGs.
In addition, recently, a National Academy of Sciences, Engineering, and Medicine
(NASEM) panel of independent experts concluded that the impacts of offshore wind
operations on North Atlantic right whales and their habitat in the Nantucket Shoals region
(a key winter foraging habitat tens of kilometers to the east of the Project area) are
uncertain due to the limited data available at this time and recognized what data is
available is largely based on models from the North Sea that have not been validated by
observations (National Academy of Sciences, 2023). The report also identifies that major
oceanographic changes have occurred to the Nantucket Shoals region over the past 25

years and it will be difficult to isolate from the much larger variability introduced by
natural and other anthropogenic sources (including climate change). This report is
specific to the Nantucket Shoals region which is unlikely to be influenced by any longterm operational effects of the Project; however, the findings in the report align with
those presented in the proposed rule. More recently, NMFS concluded ESA consultation
on Federal actions associated with the Project, including NMFS’s proposal to issue a 5year rule to Avangrid and BOEM’s approval of the Construction and Operation Plan
(COP) which covers the 30 years of the Project’s operation and subsequent
decommissioning.
Similar to the discussion presented in the proposed rule, the BiOp stated the
Project will produce a wind wake from operation of the turbines and that the foundations
themselves will lead to disruptions in local conditions; the scale of these effects is
expected to range from hundreds of meters and up to 1 km from each foundation and the
changes in conditions may alter the distribution of nutrients, primary production, and
plankton. The BiOp concluded it is not expected that the impacts to oceanic conditions
resulting from the Project will affect the oceanographic forces transporting plankton into
the area from the south and east; however, there may be effects on the distribution of
plankton more locally. The construction and operation of the Project is not expected to
alter this broad current pattern, and thus NMFS expects any alteration of the biomass of
plankton in the region, and therefore, the total food supply, to be so small that adverse
effects on ESA-listed species are not reasonably certain to occur.
Overall, there is no new scientific information regarding the general anticipated
effects of OSW construction on marine mammals and their habitat that was not discussed
in the proposed rule. The information and analysis regarding the potential effects on
marine mammals and their habitat is incorporated by reference and included in the

proposed rule is referenced and used for this final rule and is not repeated here; please
refer to the proposed rule (88 FR 37606, June 8, 2023).
Estimated Take
As noted in the Changes from the Proposed to Final Rule section, changes to
the estimated and allowable take (i.e., take that may be authorized) for several species
have been made since publication of the proposed rule based on new information from
Avangrid, recommendations received during the public comment period, and the best
available science. This section provides an estimate of the number of incidental takes that
may be authorized through this rule, which will inform both NMFS’ consideration of
“small numbers” and the negligible impact determination. The analysis related to take
incidental to HRG surveys, UXO/MEC detonation, and rare species is unchanged since
the proposed rule. However, as described above in the Changes from the Proposed
section, Avangrid re-evaluated the sound fields generated during foundation installation
and corresponding exposure estimates which is further described in the foundation
installation take section below. Takes allowed under this rule would primarily be by
Level B harassment, as use of the acoustic sources (i.e., impact and vibratory pile driving,
drilling, UXO/MEC detonation, site characterization surveys) are expected to result in
disruption of marine mammal behavioral patterns due to exposure to elevated noise
levels. Impacts such as masking and TTS can contribute to behavioral disturbances.
There is also some potential for auditory injury constituting Level A harassment to occur
in select marine mammal species incidental to the specified activities (i.e., impact pile
driving and UXO/MEC detonation). For this action, this potential is largely limited to,
though not exclusive to, mysticetes due to their hearing sensitivities and the nature of the
activities. As described below, the larger distances to the PTS thresholds, when
considering marine mammal weighting functions, demonstrate this potential. For midfrequency hearing sensitivities, when thresholds and weighting and the associated PTS

zone sizes are considered, the likelihood for PTS from the noise produced by the Project
is less than that for mysticetes. The required mitigation and monitoring measures are
expected to minimize the severity of the taking to the extent practicable. As described
previously, no serious injury or mortality is anticipated or may be authorized incidental to
the Project. Below, we describe how the take was estimated.
Generally speaking, we estimate take by considering: (1) acoustic thresholds
above which NMFS believes the best available science indicates marine mammals will be
behaviorally harassed or incur some degree of permanent hearing impairment (as well as
impulse metric (Pascal-second) and peak sound pressure level thresholds above which
marine mammals may incur non-auditory injury from underwater explosive detonations);
(2) the area or volume of water that will be ensonified above these levels in a day; (3) the
density or occurrence of marine mammals within these ensonified areas; and, (4) the
number of days of activities. We note that while these basic factors can contribute to a
basic calculation to provide an initial prediction of takes, additional information that can
qualitatively inform take estimates is also sometimes available. Below, we describe the
factors considered here in more detail and present the take estimates.
Marine Mammal Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the received level
of underwater sound above which exposed marine mammals are likely to be behaviorally
harassed (equated to Level B harassment) or to incur PTS of some degree (equated to
Level A harassment). Thresholds have also been developed identifying the received level
of in-air sound above which exposed pinnipeds would likely be behaviorally harassed. A
summary of all NMFS’ thresholds can be found at
(https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammalacoustic-technical-guidance).

Level B harassment – Though significantly driven by received level, the onset of
behavioral disturbance from anthropogenic noise exposure is also informed to varying
degrees by other factors related to the source or exposure context (e.g., frequency,
predictability, duty cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., other noises in the area) and the state of the receiving
animals (e.g., hearing, motivation, experience, demography, life stage, depth), and can be
difficult to predict (e.g., Southall et al., 2007, 2021; Ellison et al., 2012). Based on what
the available science indicates and the practical need to use a threshold based on a metric
that is both predictable and measurable for most activities, NMFS typically uses a
generalized acoustic threshold based on received level to estimate the onset of behavioral
harassment. NMFS generally predicts that marine mammals are likely to be behaviorally
harassed in a manner considered to be Level B harassment when exposed to underwater
anthropogenic noise above RMS pressure received levels (SPL) of 120 dB (re 1 μPa) for
continuous (e.g., vibratory pile driving, drilling) and above RMS SPL 160 dB re 1 μPa
for non-explosive impulsive (e.g., seismic airguns) or intermittent (e.g., scientific sonar)
sources (table 4). Generally speaking, Level B harassment take estimates based on these
behavioral harassment thresholds are expected to include any likely takes by TTS as, in
most cases, the likelihood of TTS occurs at distances from the source less than those at
which behavioral harassment is likely. TTS of a sufficient degree can manifest as
behavioral harassment, as reduced hearing sensitivity and the potential reduced
opportunities to detect important signals (e.g., conspecific communication, predators,
prey) may result in changes in behavior patterns that would not otherwise occur.
Avangrid’s construction activities include the use of continuous (e.g., vibratory
pile driving, drilling) and intermittent (e.g., impact pile driving and HRG acoustic
sources) sources; therefore, the 120 and 160 dB re 1 μPa (RMS) thresholds are
applicable.

Level A harassment – NMFS’ Technical Guidance for Assessing the Effects of
Anthropogenic Sound on Marine Mammal Hearing (Version 2.0; Technical Guidance,
2018) identifies dual criteria to assess auditory injury constituting Level A harassment to
five different marine mammal groups based on hearing sensitivity as a result of exposure
to noise from two different types of sources (i.e., impulsive or non-impulsive sources).
As dual metrics, NMFS considers onset of PTS constituting Level A harassment to have
occurred when either one of the two metrics is exceeded (i.e., metric resulting in the
largest isopleth). The Project includes the use of impulsive and non-impulsive sources.
These thresholds are provided in table 4 below. The references, analysis, and
methodology used in the development of the thresholds are described in NMFS’ 2018
Technical Guidance, which may be accessed at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammalacoustic-technical-guidance.
Table 4 – Onset of PTS (NMFS, 2018)
PTS Onset Thresholds*
(Received Level)
Hearing Group
Impulsive
Non-impulsive
Cell 1
Low-Frequency (LF)
Cell 2
Lp,0-pk,flat: 219 dB
Cetaceans
LE,p, LF,24h: 199 dB
LE,p, LF,24h: 183 dB
Cell 3
Mid-Frequency (MF)
Cell 4
Lp,0-pk,flat: 230 dB
Cetaceans
LE,p, MF,24h: 198 dB
LE,p, MF,24h: 185 dB
Cell 5
High-Frequency (HF)
Cell 6
Lp,0-pk,flat: 202 dB
Cetaceans
LE,p, HF,24h: 173 dB
LE,p,HF,24h: 155 dB
Cell 7
Phocid Pinnipeds (PW)
Cell 8
Lp,0-pk.flat: 218 dB
(Underwater)
LE,p,PW,24h: 201 dB
LE,p,PW,24h: 185 dB
Cell 9
Otariid Pinnipeds (OW)
Cell 10
Lp,0-pk,flat: 232 dB
(Underwater)
LE,p,OW,24h: 219 dB
LE,p,OW,24h: 203 dB
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound
pressure level thresholds associated with impulsive sounds, these thresholds are recommended
for consideration.

Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 µPa, and weighted
cumulative sound exposure level (LE,p) has a reference value of 1µPa2s. In this table,
thresholds are abbreviated to be more reflective of International Organization for
Standardization standards (ISO, 2017). The subscript “flat” is being included to indicate peak
sound pressure are flat weighted or unweighted within the generalized hearing range of marine
mammals (i.e., 7 Hz to 160 kHz). The subscript associated with cumulative sound exposure
level thresholds indicates the designated marine mammal auditory weighting function (LF,
MF, and HF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation
period is 24 hours. The weighted cumulative sound exposure level thresholds could be
exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle).
When possible, it is valuable for action proponents to indicate the conditions under which
these thresholds will be exceeded.
Explosives Source Thresholds
Based on the best scientific information available, NMFS uses the acoustic and
pressure thresholds indicated in table 5 to predict the onset of PTS and TTS during
UXO/MEC detonation. For a single detonation (within a 24-hour period), NMFS relies
on the TTS onset threshold to assess the likelihood for Level B harassment. The final rule
is conditioned such that Avangrid would limit detonations to one per day and would be
limited to daylight hours only.
Table 5 – PTS Onset, TTS Onset, for Underwater Explosives (NMFS, 2018)
Hearing Group

PTS Impulsive Thresholds

TTS Impulsive Thresholds

Low-Frequency (LF)
Cetaceans

Cell 1
Lpk,flat: 219 dB
LE,LF,24h: 183 dB

Cell 2
Lpk,flat: 213 dB
LE,LF,24h: 168 dB

Mid-Frequency (MF)
Cetaceans

Cell 4
Lpk,flat: 230 dB
LE,MF,24h: 185 dB

Cell 5
Lpk,flat: 224 dB
LE,MF,24h: 170 dB

High-Frequency (HF)
Cetaceans

Cell 7
Lpk,flat: 202 dB
LE,HF,24h: 155 dB

Cell 8
Lpk,flat: 196 dB
LE,HF,24h: 140 dB

Phocid Pinnipeds (PW)
(Underwater)

Cell 10
Lpk,flat: 218 dB
LE,PW,24h: 185 dB

Cell 11
Lpk,flat: 212 dB
LE,PW,24h: 170 dB

* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest
isopleth for calculating PTS/TTS onset.
Note: Peak sound pressure (Lpk) has a reference value of 1 µPa, and cumulative sound
exposure level (LE) has a reference value of 1µPa2s. In this table, thresholds are abbreviated to
reflect American National Standards Institute standards (ANSI, 2013). However, ANSI defines
peak sound pressure as incorporating frequency weighting, which is not the intent for this

Technical Guidance. Hence, the subscript “flat” is being included to indicate peak sound
pressure should be flat weighted or unweighted within the overall marine mammal generalized
hearing range. The subscript associated with cumulative sound exposure level thresholds
indicates the designated marine mammal auditory weighting function (LF, MF, and HF
cetaceans, and PW pinnipeds) and that the recommended accumulation period is 24 hours. The
cumulative sound exposure level thresholds could be exceeded in a multitude of ways (i.e.,
varying exposure levels and durations, duty cycle). When possible, it is valuable for action
proponents to indicate the conditions under which these acoustic thresholds will be exceeded.

Additional thresholds for non-auditory injury to lung and gastrointestinal (GI)
tracts from the blast shock wave and/or onset of high peak pressures are also relevant (at
relatively close ranges) as UXO/MEC detonations, in general, have potential to result in
mortality and non-auditory injury (table 6). Marine mammal lung injury criteria have
been developed by the U.S. Navy (DoN (U.S. Department of the Navy), 2017), and
adopted by NMFS, and are based on the mass of the animal and the depth at which it is
present in the water column due to blast pressure. This means that specific decibel levels
for each hearing group are not provided and instead, the criteria are presented as
equations that allow for incorporation of specific mass and depth values. The GI tract
injury threshold is based on peak pressure. The modified Goertner equations below
represent the potential onset of lung injury and GI tract injury (table 6).
Table 6 – Lung and G.I. Tract Injury Thresholds (DoN, 2017)
Hearing Group

Mortality
(Severe lung injury)*

Slight Lung Injury*

G.I. Tract Injury

All Marine Mammals

Cell 1
Modified Goertner
model; Equation 1

Cell 2
Modified Goertner
model; Equation 2

Cell 3
Lpk,flat: 237 dB

* Lung injury (severe and slight) thresholds are dependent on animal mass (Recommendation:
table C.9 from DoN (2017) based on adult and/or calf/pup mass by species).
Note: Peak sound pressure (Lpk) has a reference value of 1 µPa. In this table, thresholds are
abbreviated to reflect American National Standards Institute standards (ANSI, 2013).
However, ANSI defines peak sound pressure as incorporating frequency weighting, which is
not the intent for this Technical Guidance. Hence, the subscript “flat” is being included to
indicate peak sound pressure should be flat weighted or unweighted within the overall marine
mammal generalized hearing range.

Modified Goertner Equations for severe and slight lung injury (Pascal-second)
Equation 1: 103M1/3(1 + D/10.1)1/6 Pa-s
Equation 2: 47.5M1/3(1 + D/10.1)1/6 Pa-s
M = animal (adult and/or calf/pup) mass (kg) (table C.9 in DoN, 2017)
D = animal depth (m)

Below, we discuss the marine mammal density information, acoustic modeling,
and take estimation for each of Avangrid’s specified activities. NMFS has carefully
considered all information and analysis presented by the applicant as well as all other
applicable information and, based on the best available science, concurs that the
applicant’s estimates of the types and amounts of take for each species and stock are
complete and accurate.
Marine Mammal Density and Occurrence
In this section we provide the information about the presence, density, or group
dynamics of marine mammals that will inform the take calculations. Depending on the
species and as described in the take estimation section for each activity, take estimates
may be based on the Roberts et al. (2023) density estimates, marine mammal monitoring
results from HRG surveys, or average group sizes.
Habitat-based density models produced by the Duke University Marine
Geospatial Ecology Laboratory and the Marine-life Data and Analysis Team, based on
the best available marine mammal data from 1992 to 2022 obtained in a collaboration
between Duke University, the Northeast Regional Planning Body, the University of
North Carolina Wilmington, the Virginia Aquarium and Marine Science Center, and
NOAA (Roberts et al., 2016a, 2016b, 2017, 2018, 2020, 2021a, 2021b, 2023), represent
the best available science regarding marine mammal densities in the Project Area. More
recently, these data have been updated with new modeling results and include density
estimates for pinnipeds (Roberts et al., 2016b, 2017, 2018, 2023). Density data are

subdivided into five separate raster data layers for each species, including: Abundance
(density); 95 percent Confidence Interval of Abundance; 5 percent Confidence Interval of
Abundance; Standard Error of Abundance; and Coefficient of Variation of Abundance.
The methods for calculating monthly, seasonal and annual densities have not
changed since the proposed rule. For foundation installation, the width of the perimeter
around the activity area used to select density data from the Roberts et al., 2022 models
was based on the largest 10-dB attenuated exposure range (ER95%; the Level B
harassment range) applicable to that activity. The applicant calculated monthly densities
for each species using grid cells within the lease area and a perimeter around the lease
area that represented the ER95% ensonified area for each sound-producing activity. The
mean density for each month was determined by calculating the unweighted mean of all 5
× 5 km grid cells partially or fully within the analysis polygon. Densities were computed
monthly for the May–December period to coincide with proposed foundation pile driving
activities. In cases where monthly densities were unavailable, annual mean densities were
used instead. For cases with vibratory setting of piles followed by impact pile driving,
and impact pile driving alone (i.e., all pile driving scenarios), densities were calculated
within buffered polygons of various ranges around the Lease Area perimeter. The
following ranges were pre-selected: 10, 25, and 50 km. For each species, foundation type,
and attenuation level, the most appropriate density perimeter was selected from this list.
The range was selected using the 95th percentile exposure range (ER95%) for each case,
using the next highest range. For example, if the ER95% was 8.5 km, the 10 km perimeter
would be used. In cases where the ER95% was larger than 50 km, the 50-km perimeter was
used. The 50 km limit is derived from studies of mysticetes that demonstrate received
levels, distance from the source, and behavioral context are known to influence the
probability of behavioral response (Dunlop et al., 2017).

For drilling, it was assumed that the activity would occur in three areas of interest:
J1, M1, and M2 (i.e., three modeled locations). The density perimeter was determined
using the longest 10-dB attenuated 95th percentile acoustic range to the behavioral
threshold (R95%) for all locations, rounded up to the nearest 5 km, and then applied
around the entire lease area (i.e., 7.1 km rounded up to 10 km). Monthly densities were
calculated for each species as the average of the densities from all Roberts et al., 2022
model grid cells that overlap partially or completely with the area of interest. Cells
entirely on land were not included, but cells that overlap only partially with land were
included.
As described in the proposed rule, for UXO/MEC detonations, the applicant
commissioned a UXO/MEC desktop study in which a comprehensive historic analysis of
all activities which may have contributed to potential UXO/MEC presence in the project
area. The applicant evaluated the risk of encountering the potential UXO/MECs and
identified areas of moderate risk of UXO/MEC presence then commissioned an acoustic
modeling study, as described in the proposed rule. As a result of this process, the largest
SEL-based TTS-onset acoustic ranges across all hearing groups was applied it to the
moderate UXO/MEC risk areas, resulting in a 14.1-km perimeter for the shallow water
segment of the OECC and a 13.8-km density perimeter for the deep water segment of the
OECC as well as the SWDA.
For HRG surveys, the applicant applied all grid cells within the survey corridor.
No buffer was applied given the small distance to Level B harassment (<200 m) during
surveys compared to the grid cell size in the Roberts et al., 2022 density models (5 x 5
km). To estimate densities for the HRG surveys occurring both within the Lease Area and
within the export cable routes, the applicant mapped density data from Roberts et al.
(2023) within the boundary of the Project Area using geographic information systems.
The applicant then averaged maximum monthly densities (as reported by Roberts et al.,

2023) by season over the survey duration (for winter (December through February),
spring (March through May), summer (June through August), and fall (September
through November)) within the HRG survey area. The maximum average seasonal
density, for each species, was then carried forward in the take calculations (table 6).
For several marine mammal species, Roberts et al. (2023) does not differentiate
by species and instead combines them into guilds. This is true for long-finned and shortfinned pilot whales (pilot whale spp.), beaked whales, and harbor, harp, hooded, and gray
seals (seals), where a pooled density by guild is the only value available from the data
that is not partitioned by stock.
Below, we describe observational data from monitoring reports and average group
size information, both of which are appropriate to inform take estimates for certain
activities or species in lieu of density estimates.
For previous modeling efforts’ marine mammal densities, for long- and shortfinned pilot whales, the guild density from Roberts et al. (2016a, 2022b) was scaled by
the relative stock sizes based on the best available abundance estimate from the 2023
SARs (Hayes et al., 2022). Similarly, densities were provided for seals as a guild
consisting primarily of harbor and gray seals (Roberts et al., 2016a, 2022b), gray and
harbor seal densities were scaled by relative 2023 SARs (Hayes et al., 2022) abundance.
For the recently updated modeling efforts- vibratory setting followed by impact pile
driving, impact pile driving alone, drilling, UXO/MEC detonations, and HRG when
calculating exposures for individual pilot whale and seal species, the guild densities
provided by Roberts et al. (2016a, 2022b) were scaled by the relative abundances of the
species in each guild, using the best available estimates of local abundance, to get
species-specific density estimates surrounding the Lease Area. In estimating local
abundances, all distribution data from the two pilot whale species and three seal species
were downloaded from the Ocean Biodiversity Information System (OBIS) data

repository (available at https://obis.org/). After reviewing the available datasets, it was
deemed that data available in OBIS in Rhode Island and Massachusetts waters are the
best available for the three seal species because of their overlap with the Lease Area.
For seals, OBIS reported 86 observations of gray seals, 129 observations of
harbor seals, and 93 observations of harp seals. Therefore, the proportions of 0.28
(86/308), 0.42 (129/308), and 0.30 (93/308) were used to scale the seals’ guild densities
for the three seal species, respectively. The best data available for pilot whales came from
AMAPPS data in Rhode Island and Massachusetts waters. The proportions of 0.80 for
long-finned and 0.20 for short-finned pilot whales were used (Palka et al., 2021).
For uncommon species, the predicted densities from the Roberts et al., 2022
models are very low and the resulting density-based exposure estimate is less than a
single animal or a typical group size for the species. In such cases, densities were not
used but the take request is based on the species' average group size (tables 10 and 11).
When this occurred, the mean group sizes used to correct Level B harassment take
estimates, as shown in tables 10 and 11, for modeled cetacean species were derived from
AMAPPS data from 2010–2019 NE shipboard distance sampling surveys (Palka et al.,
2021) or informed by data from 2018–2021 HRG surveys conducted near the project area
(Vineyard Wind, 2018, 2020a, 2020c, 2021a). Mean group size was calculated as the
number of individuals divided by the number of groups from table 6–5 of Palka et al.
(2021), which summarizes the 2010–2019 AMAPPS NE shipboard distance surveys.
Summer sightings (June 1 to August 31) were chosen for these calculations because
many species were not observed during fall surveys, and surveys were not conducted
during spring or winter. When site assessment survey data showed a larger mean group
size than was shown by the AMAPPS data, the site assessment survey group size was
applied to take calculations.

In cases where the exposure estimate was less than the mean group size, we
predict that if one group member were to be exposed within the Level B harassment
threshold, then it is reasonable to expect that all animals in the same group could be.
Therefore, for species for which the annual number of predicted exposures above
threshold was less than the mean group size, the annual number of expected takes was
increased to one mean group size rounded up to the nearest integer. Correcting for group
size for these species is used as a conservative measure to ensure that in the event of a
close encounter with the species, a reasonably expected number of individuals (i.e.,
average group size) is accounted for in the take request.
As described previously, density-based exposure calculations were not conducted
for species considered rare in the project area. There are few to zero sightings of these
species in the sources used above to calculate group size for the modeled species, so an
alternative method had to be developed. Group size calculations for rare species used
sighting data from the Ocean Biodiversity Information System database (OBIS, 2021).
All records for each of the rare species were extracted from the OBIS database and then
filtered to include only the area from approximately Cape Hatteras to the Gulf of Maine
(35° N to 43° N) and from the coast (76° W) out to the continental shelf edge (66° W) to
provide a more precise estimate of potential group size in the SWDA than would be
expected using all OBIS records. The OBIS data were further filtered to remove stranding
data, because the group size of stranded animals does not necessarily reflect the group
size of free-ranging animals. The one exception to this was the hooded seal—all records
of this species in this area from the OBIS database were of single, stranded individuals,
and thus a group size of one was used. This number is likely reflective of any freeswimming hooded seal that would occur in the area because this is an Arctic species and
only single vagrant animals would be expected. Finally, data from digital aerial surveys
were filtered out of this larger dataset because, although useful in determining

presence/absence, these data provide no information on group size. The
“individualCount” variable in the OBIS data was used to calculate minimum, maximum,
and average group sizes for these rare species (table 16 in the ITA application).
For many of these rare species, in particular the delphinids, maximum group sizes
in OBIS can be in the hundreds or even up to thousands of animals. However, because
these animals are rare in the project area, as it is not their preferred habitat, we think that
they would be unlikely to form such large aggregations in this area and, further, it is
unlikely that any such large aggregations would all swim with the small HRG Level B
harassment zone. Thus, like with uncommon species, the average group size (rounded up
to a whole number) based on the previously described observer data was used in the take
calculations for these species instead of the OBIS data to refine the group sizes to what
had been previously observed in similar surveys. Group sizes relevant to the project area
can be informed by PSO sightings during site characterization surveys (tables 10 and 11).
For example, white-beaked dolphins were recorded in both 2019 and 2020 during HRG
surveys in this area (Vineyard Wind, 2019, 2020) with the sighting of white-beaked
dolphins in 2019 consisting of 30 animals. Other rare species encountered in the survey
area during previous HRG surveys include false killer whales in 2019 (5 individuals) and
2021 (1 individual) (Vineyard Wind, 2020c, 2020b) and killer whales in 2022 (2
individuals; data not yet submitted). For these species the take estimates use the average
observed group size from PSO sightings.
Additional detail regarding the density and occurrence as well as the assumptions
and methodology used to estimate take for specific activities is included in the activityspecific subsections below and in Section 6.1 of the ITA application. Average group sizes
used in take estimates, where applicable, for all activities are provided in tables 10 and
11.

Tables 7, 8, and 9, below demonstrate all of the densities used in the exposure and
take analyses. Densities differed depending on the types of piles installed and manner of
take being assessed given the large spatial extent differences between ER95% for Level A
harassment and Level B harassment. Tables 10 and 11 show the average marine mammal
group sizes calculated based on the methods described above.

Table 7 – Mean Monthly Marine Mammal Density Estimates (Animals/100 km2) for Foundation Installation Impact
Pile Driving, Vibratory Pile Setting Followed by Impact Pile Driving, and Drilling (Level B) Considering a 10-km
Buffer Around the Lease Areaa
Annual May-Dec
Mean
Mean

Species

Jan

Feb

Mar

Apr

May

Jun

July

Aug

Sep

Oct

Nov

Dec

North
Atlanti
c right
whaleb

0.387

0.461

0.456

0.478

0.295

0.050

0.022

0.018

0.028

0.052

0.068

0.197

0.209

0.091

Fin
whaleb

0.215

0.166

0.107

0.164

0.272

0.256

0.438

0.366

0.227

0.057

0.051

0.141

0.205

0.226

Humpb
ack
whale

0.031

0.023

0.043

0.149

0.294

0.307

0.172

0.120

0.167

0.236

0.190

0.030

0.147

0.189

Minke
whale

0.113

0.137

0.136

0.806

1.728

1.637

0.700

0.471

0.516

0.465

0.052

0.077

0.570

0.706

Sei
whaleb

0.039

0.021

0.044

0.112

0.192

0.052

0.013

0.011

0.019

0.036

0.079

0.065

0.057

0.058

Sperm
whaleb

0.031

0.011

0.013

0.003

0.014

0.028

0.038

0.107

0.070

0.057

0.031

0.020

0.035

0.046

Atlanti
c
spotted
dolphin

0.001

0.000

0.001

0.003

0.018

0.025

0.031

0.054

0.273

0.431

0.179

0.018

0.086

0.128

Atlanti
c
whitesided
dolphin

2.049

1.230

0.850

1.313

3.322

3.003

1.392

0.730

1.654

2.431

1.791

2.440

1.850

2.095

Bottlen
ose

0.495

0.111

0.059

0.156

0.814

1.358

1.479

1.659

1.483

1.337

1.255

1.101

0.942

1.311

dolphin
,
offshor
e
Comm
on
dolphin

7.130

2.455

1.884

3.258

6.254

13.905

10.533

14.446

25.703

22.676

11.103

10.774

10.844

14.424

Longfinned
pilot
whalec

0.189

0.189

0.189

0.189

0.189

0.189

0.189

0.189

0.189

0.189

0.189

0.189

0.189

0.189

Shortfinned
pilot
whalec

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

Risso’s
dolphin

0.043

0.004

0.002

0.018

0.096

0.048

0.068

0.128

0.158

0.087

0.120

0.179

0.079

0.111

Harbor
porpois
e

10.007

10.784

10.277

8.914

6.741

0.960

0.880

0.848

0.988

1.271

1.418

5.812

4.908

2.365

Gray
seald

5.395

5.603

4.176

3.203

4.716

0.806

0.088

0.094

0.226

0.500

1.768

4.534

2.592

1.591

Harbor
seald

8.093

8.404

6.265

4.804

7.074

1.209

0.132

0.140

0.339

0.750

2.652

6.802

3.889

2.387

Harp
seald

5.781

6.003

4.475

3.432

5.053

0.864

0.094

0.100

0.242

0.535

1.894

4.858

2.778

1.705

Note: All densities used for impact pile driving and drilling used the 10-km density table. For vibratory pile driving, for each
species, foundation type, and attenuation level, the most appropriate density perimeter was used (10 km, 25 km, 50 km) based
on the 95th percentile exposure range (ER95%). Therefore, vibratory pile driving exposure estimates used 10-km for Level A
harassment and a mixture of the 25 and 50-km tables for Level B harassment.
a – Density estimates are calculated from the 2022 Duke Habitat-Based Marine Mammal Density Models (Roberts et al.,
2016; Roberts et al., 2022).

b – Listed as Endangered under the ESA.
c – Density adjusted by relative local abundance.
d – Gray and harbor seal densities are the seals guild density scaled by their relative local abundances; gray seals are used as a
surrogate for harp seals.
Table 8 – Mean Monthly Marine Mammal Density Estimates (Animals/100 km2) for Vibratory Pile Setting Followed by
Impact Pile Driving (Level B harassmenta) Considering a 25-km Perimeter Around the Lease Area
Annual May-Dec
Mean
Mean

Species

Jan

Feb

Mar

Apr

May

Jun

July

Aug

Sep

Oct

Nov

Dec

North
Atlanti
c right
whaleb

0.443

0.523

0.493

0.471

0.279

0.052

0.026

0.019

0.029

0.050

0.084

0.257

0.227

0.100

Fin
whaleb

0.213

0.161

0.118

0.165

0.272

0.247

0.391

0.316

0.221

0.068

0.056

0.146

0.198

0.214

Humpb
ack
whale

0.034

0.026

0.044

0.146

0.271

0.284

0.156

0.107

0.147

0.202

0.174

0.035

0.135

0.172

Minke
whale

0.119

0.138

0.143

0.790

1.617

1.468

0.622

0.397

0.436

0.436

0.054

0.084

0.525

0.639

Sei
whaleb

0.036

0.022

0.045

0.115

0.186

0.053

0.013

0.010

0.017

0.035

0.080

0.066

0.056

0.058

Sperm
whaleb

0.030

0.012

0.012

0.003

0.013

0.028

0.038

0.115

0.059

0.042

0.029

0.021

0.034

0.043

Atlanti
c
spotted
dolphin

0.001

<0.001

<0.001

0.003

0.027

0.042

0.034

0.055

0.282

0.577

0.181

0.020

0.102

0.152

Atlanti
c
whitesided
dolphin

2.062

1.314

0.913

1.383

3.179

2.994

1.368

0.644

1.532

2.246

1.741

2.357

1.811

2.008

Bottlen
ose
dolphin
,
offshor
e

0.476

0.118

0.066

0.174

0.835

1.390

1.491

1.624

1.528

1.414

1.324

1.077

0.960

1.335

Comm
on
dolphin

7.388

2.799

2.212

3.612

6.556

13.827

10.602

13.820

23.538

24.395

12.882

11.716

11.112

14.667

Longfinned
pilot
whalec

0.188

0.188

0.188

0.188

0.188

0.188

0.188

0.188

0.188

0.188

0.188

0.188

0.188

0.188

Shortfinned
pilot
whalec

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

0.047

Risso’s
dolphin

0.051

0.006

0.003

0.021

0.112

0.070

0.092

0.170

0.223

0.122

0.128

0.174

0.098

0.136

Harbor
porpois
e

9.007

9.787

9.321

8.194

5.913

1.172

1.147

1.030

1.003

1.222

1.421

5.478

4.558

2.298

Gray
seald

5.553

5.401

3.946

3.485

5.109

1.750

0.315

0.296

0.497

0.881

2.108

4.485

2.819

1.930

Harbor
seald

8.329

8.101

5.919

5.227

7.664

2.625

0.473

0.443

0.745

1.322

3.161

6.728

4.228

2.895

Harp
seald

5.949

5.786

4.228

3.733

5.474

1.875

0.338

0.317

0.532

0.944

2.258

4.806

3.020

2.068

a – The Level B harassment exposure ranges (ER95%) for vibratory pile driving informed which density estimates were used.
For species whose exposure range was more than 10 km and up to 25 km, this table’s densities were used. For those more
than 25 km, the 50 km densities were used.
Density estimates are calculated from the 2022 Duke Habitat-Based Marine Mammal Density Models (Roberts et al., 2016;
Roberts et al., 2022).
b – Listed as Endangered under the ESA.
c – Density adjusted by relative local abundance.
d – Gray and harbor seal densities are the seals guild density scaled by their relative local abundances; gray seals are used as a
surrogate for harp seals.
Table 9 – Mean Monthly Marine Mammal Density Estimates (Animals/100 km2) for Vibratory Pile Setting Followed by
Impact Pile Driving Considering a 50-km Perimeter Around the Lease Areaa
Annual May-Dec
Mean
Mean

Species

Jan

Feb

Mar

Apr

May

Jun

July

Aug

Sep

Oct

Nov

Dec

North
Atlanti
c right
whaleb

0.565

0.674

0.580

0.511

0.321

0.084

0.055

0.033

0.045

0.055

0.119

0.361

0.284

0.134

Fin
whaleb

0.194

0.158

0.142

0.169

0.256

0.246

0.383

0.316

0.244

0.093

0.060

0.128

0.199

0.216

Humpb
ack
whale

0.037

0.030

0.044

0.167

0.270

0.300

0.158

0.096

0.124

0.177

0.164

0.041

0.134

0.166

Minke
whale

0.106

0.121

0.138

0.652

1.298

1.163

0.504

0.302

0.338

0.387

0.051

0.080

0.428

0.515

Sei
whaleb

0.030

0.024

0.045

0.123

0.181

0.059

0.016

0.009

0.014

0.034

0.076

0.058

0.056

0.056

Sperm
whaleb

0.031

0.018

0.018

0.005

0.014

0.029

0.039

0.111

0.053

0.035

0.028

0.028

0.034

0.042

Atlanti
c
spotted
dolphin

0.002

<0.001

<0.001

0.006

0.073

0.182

0.052

0.084

0.449

1.025

0.238

0.027

0.178

0.266

Atlanti
c
whitesided
dolphin

2.430

1.744

1.187

1.652

3.170

3.373

1.468

0.508

1.265

2.153

1.732

2.428

1.926

2.012

Bottlen
ose
dolphin
,
offshor
e

0.691

0.222

0.130

0.293

1.119

1.863

1.924

1.935

2.001

1.972

1.905

1.455

1.293

1.772

Comm
on
dolphin

10.202

5.127

4.047

5.422

8.950

18.237

13.103

14.754

22.465

30.637

18.664

15.127

13.895

17.742

Longfinned
pilot
whalec

0.231

0.231

0.231

0.231

0.231

0.231

0.231

0.231

0.231

0.231

0.231

0.231

0.231

0.231

Shortfinned
pilot
whalec

0.058

0.058

0.058

0.058

0.058

0.058

0.058

0.058

0.058

0.058

0.058

0.058

0.058

0.058

Risso’s
dolphin

0.110

0.023

0.009

0.040

0.230

0.227

0.299

0.488

0.642

0.322

0.190

0.218

0.233

0.327

Harbor
porpois
e

6.731

7.481

7.192

6.632

4.590

1.481

1.388

1.038

0.852

1.130

1.383

4.273

3.681

2.017

Gray
seald

5.346

4.893

4.081

4.674

6.820

5.412

1.595

1.318

1.519

2.863

3.322

4.748

3.882

3.450

Harbor
seald

8.019

7.339

6.121

7.011

10.229

8.118

2.392

1.977

2.279

4.295

4.982

7.122

5.824

5.174

Harp
seald

5.728

5.242

4.372

5.008

7.307

5.798

1.709

1.412

1.628

3.068

3.559

5.087

4.160

3.696

a – Density estimates are calculated from the 2022 Duke Habitat-Based Marine Mammal Density Models (Roberts et al.,
2016; Roberts et al., 2022). Species with exposure ranges greater than 25 km used the densities in this table.
b – Listed as Endangered under the ESA.
c – Density adjusted by relative local abundance
d – Gray and harbor seal densities are the seals guild density scaled by their relative local abundances; gray seals are used as a
surrogate for harp seals.
Table 10 – Average Marine Mammal Species Group Sizes
Species

Number Of Groups
(AMAPPS Data)a

Number Of Animals
(AMAPPS Data)a

Mean Group Size
(AMAPPS Data)a

Mean Group Size
(PSO Data)b

Group Size Applied to
Take Requestc

North Atlantic right
whaled

4

2.0

1.5

Fin whaled

533

1.5

1.6

Humpback whale

370

2.4

1.5

Minke whale

32

1.0

1.1

Sei whaled

28

1.4

1.0

Sperm whaled

491

1.6

1.3

Atlantic spotted
dolphin

1,760

29.3

Not observed

Atlantic white-sided
dolphin

61

20.3

27.5

Bottlenose dolphin,
offshore

3,865

11.2

17.9

Common dolphin

19,802

44.6

14.0

Long-finned pilot
whale

666

16.2

5.6

Short-finned pilot
whale

2,050

8.9

Not observed

Risso’s dolphin

3,131

6.4

Not observed

Harbor porpoise

6

1.5

1.3

Gray seal

202

1.4

1.2

Harbor seal

202

1.4

2.0

Harp seal

202

1.4

Not observed

a – Mean group size for cetaceans from 2010–2019 AMAPPS NE shipboard distance sampling surveys (table 6-5 of Palka et
al. (2021)), and for seals from 2010–2013 AMAPPS NE aerial surveys for all seals because most were not identified to species
(table 19.1 of Palka et al. (2017)).
b – Mean group size from 2018–2021 PSO sightings data from 2018–2021 HRG surveys conducted by the Proponent
(Vineyard Wind, 2018, 2020a, 2020c, 2021a).
c – Group size used for takes by Level B harassment correction is higher of AMAPPS data and PSO data rounded up to an
integer.
d – Listed as Endangered under the ESA.
Table 11 – Average Marine Mammal Group Sizes Used for Rare Species in Take Estimate Calculations
Species

Minimum Group Size
(OBIS)

Maximum Group Size
(OBIS)

Mean Group Size
(OBIS)

Mean Group Size
(PSO Reports)

Group Size Used In
Take Estimates

Blue whalea

2

1.0

NA

Dwarf sperm whale

5

1.7

NA

Pygmy sperm whale

3

1.3

NA

Cuvier's beaked whale

10

2.8

NA

Blainville's beaked
whale

4

3.3

NA

Gervais' beaked whale

12

3.5

NA

Sowerby's beaked
whale

10

3.5

NA

True's beaked whale

5

2.9

NA

Northern bottlenose
whale

7

3.7

NA

Clymene dolphin

1,000

166.8

NA

False killer whaleb

30

6.3

5

Fraser's dolphin

250

191.7

NA

Killer whaleb

40

7.3

2

Melon-headed whale

210

108.8

NA

Pan-tropical spotted
dolphin

300

59.3

NA

Pygmy killer whale

10

4.5

NA

Rough-toothed
dolphin

45

13.1

NA

Spinner dolphin

170

50.4

NA

Striped dolphin

500

63.8

NA

White-beaked
dolphinb

200

13.5

30

Hooded sealc

1

1.0

NA

a – Listed as Endangered under the ESA.
b – Mean group size for these species from 2018–2021 PSO sightings data from 2018–2021 HRG surveys conducted by Park
City Wind (Vineyard Wind, 2018, 2020a, 2020c, 2021a).

c – All records of hooded seals in the OBIS database for this region were strandings of single animals.

Modeling and Take Estimation
Avangrid estimated take using both sophisticated sound and animal movement modeling
to account for the movement and behavior of marine mammals and their exposure to the
underwater sound fields produced during foundation impact and vibratory pile driving, as
described below. Avangrid estimated the potential for harassment from drilling, HRG, and
UXO/MEC detonations using a simplified “static” method wherein the take estimates are the
product of density, ensonified area above the NMFS defined threshold (e.g., unweighted 160 dB
SPLrms) levels, and number of days of installation. Animal movement modeling was not
conducted for drilling, HRG, and UXO/MEC detonations.
In some cases, the exposure estimates based on either the animal movement modeling or
static methods described above directly informed the amount of take requested; in other cases,
adjustments were made based on previously collected monitoring data or average group size as
described above. In all cases, Avangrid requested, and NMFS may authorize, take based on the
highest amount of exposures estimated from any given method.
Below we present the take estimate methodologies associated with each activity.
WTG and ESP Foundation Installation
WTG and ESP installation activities have the likelihood to result in harassment of marine
mammals from pile driving and drilling.
Since the proposed rule, the applicant refined the modeling methodology for impact pile
driving and vibratory pile setting (section 1.7 in the January 2024 Application Update). In the
original modeling (impact pile driving for the July 2022 LOA application), JASCO modeled
impact pile driving source characteristics using an energy-based parabolic equation (PE) model
(JASCO’s Marine Operations Noise Model (MONM)) to compute the near-field equivalent
source before long range propagation. In this update, JASCO’s Full-Wave PE RAM model
(FWRAM) was used to compute the near-field equivalent source before the long-range
propagation was computed (also using FWRAM). Using FWRAM over MONM is an

improvement because it calculates full synthetic pressure waveforms (in the time domain), as
opposed to summed energy independent of time. Like MONM, FWRAM is range dependent for
range-varying marine acoustic environments and takes environmental inputs (bathymetry, water
sound speed profile, and seabed geoacoustic profile) into account. FWRAM computes pressure
waveforms via Fourier synthesis of the modeled acoustic transfer function in closely spaced
frequency bands, and employs the array starter method to accurately model sound propagation
from a spatially distributed source (MacGillivray and Chapman, 2012). Ultimately, little
difference was observed between the prior sound fields with near-field equivalents computed
using MONM versus the current modeling with FWRAM but FWRAM is a more accurate model
as it allows direct calculation of peak and RMS sound pressure levels. Both models use a wideangle parabolic equation solution to the acoustic wave equation (Collins, 1993), based on a
version of the US Naval Research Laboratory’s Range-dependent Acoustic Model (RAM),
which has been modified to account for a solid seabed (Collins, 1993; Zhang and Tindle 1995).
The practical spreading loss approach described for vibratory pile driving in the proposed
rule has been replaced with acoustic modeling, similar to the refined impact pile driving
methodology. A quantitative acoustic assessment was conducted by Avangrid of the potential
impacts to marine mammals from vibratory pile setting followed by impact pile driving activity
during installation. As vibratory pile driving will be used on the same foundations subject to
impact pile driving (sequentially not concurrently), acoustic modeling was completed for
vibratory setting of piles followed by impact pile driving, and exposures were modeled using
animal movement modeling as described in the impact pile driving model. One second long
vibratory forcing functions were computed for the 12 and 13 m monopile and the 4-m jacket
foundations, using GRL’s Wave Equation Analysis (GRLWEAP, 2010; GRLWEAP Pile
Dynamics, 2010). Non-linearities were introduced to the vibratory forcing functions based on the
decay rate observed in data measured during vibratory pile driving of smaller diameter piles
(Quijano et al., 2017). The resulting forcing functions serve as inputs to JASCO’s pile driving

source model (PDSM) used to estimate an equivalent acoustic source represented by a linear
array of monopoles evenly distributed along the pile. Acoustic propagation modeling used
FWRAM that combine the outputs of the source model with the spatial and temporal
environmental context (e.g., location, oceanographic conditions, and seabed type) to estimate
sound fields. Unchanged from the proposed rule, NMFS notes that no hammer parameters were
available for either a 5000 or 6000 kJ hammer for use in GRLWEAP 2010; Avangrid modeled
energies of the 5500 kJ hammer were scaled using their stroke length to represent the effect of
the forcing functions for the two different hammers approximated.
Table 12 – Key Piling Assumptions Used in the Source Modeling
Foundation
Type

Modeled
maximum
impact
hammer
energy (kJ)

Pile length (m)

Pile wall
thickness
(mm)

Expected
penetration
(m)

Max number
of piles per
day

12-m
Monopile

5,000

200

2

12-m
Monopile

6,000

200

2

13-m
Monopile

5,000

200

2

4-m Pin Pile
(Jacket)

3,500

100

4

Avangrid also updated source and propagation modeling approaches associated with
estimating impacts from drilling. The proposed rule assumed an unattenuated source level of
193.3 dB re 1 μPa (as estimated by Austin et al. (2018) and therefore, assuming 10 dB of
attenuation as sound attenuation measures were proposed to be required, applied a 183.3 dB SPL
source level to the analysis. Avangrid had applied a practical spreading loss model (15logR) to
that source level, resulting in a 16.6-km distance to NMFS 120 dB SPL Level B harassment
threshold. For this final rule, Avangrid modeled drilling noise at the source and conducted more
sophisticated propagation modeling. To model drilling, the three representative source levels
estimated by Austin et al. (2018) for the 10–32,000 Hz band were averaged with an average

broadband level of 191.6 dB re 1 µPa2·s m2. These modeling locations were selected as they
represent the range of water depths in the Lease Area. MONM was used to predict SEL and SPL
sound fields up to 1 kHz at a representative location near the proposed drilling sites considering
the influence of bathymetry, seabed, water sound speed, and water attenuation. From 1 to 25
kHz, the BELLHOP ray tracing model (Porter and Liu, 1994) was used to predict sound fields at
the same representative location using from 2512 to 5012 geometric beams, increasing the beam
coverage with frequency. The total sound energy transmission loss was computed at the center
frequencies of decidecade bands as a function of range and depth from the source. MONMBELLHOP accounts for sound attenuation due to energy absorption through ion relaxation and
viscosity of water in addition to acoustic attenuation due to reflection at the medium boundaries
and internal layers (Fisher and Simmons 1977). The former type of sound attenuation is
important for frequencies higher than 5 kHz and cannot be neglected without noticeably
affecting the model results. The drill was represented as a point source in the mid-water column
at each site. The mid-water depth is a conservative representation of the noise source across the
drill bit. The acoustic field in three dimensions was generated by modeling two-dimensional (2D) vertical planes radially spaced at 2.5° in a 360° swath around the source (N x 2-D).
Composite broadband received SEL were computed by summing the received decidecade band
levels across frequency and taking the maximum-over-depth. Overall, the average source levels
per decidecade band center frequency were used in MONM to predict SEL and SPL sound fields
up to 1 kHz, and a BELLHOP ray tracing model (Porter and Liu 1994) was used from 1–32 kHz,
at a representative location near the proposed drilling sites considering the influence of
bathymetry, seabed, water sound speed, and water attenuation. The modeled unweighted SPL
levels at 750 m were 135.25–136.33 dB re 1 µPa during the summer. The corresponding
unweighted cumulative SEL levels at 750 m are 185.07–185.24 dB re 1 µPa2·s during the
summer.

Similar to the proposed rule, modeling assumed that drilling activity could occur for a
full 24 hours during any given day although it is not expected that drilling would be required up
to 24 hours, More details on the drilling modeling methods and assumptions can be found in
more detail in the January 2024 Drilling Technical Memo on our website
(https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llcconstruction-new-england-wind-offshore-wind).
JASCO conducted exposure modeling for impact driving in the same manner as
described in the proposed rule for impact driving. For this final rule, exposure modeling was also
conducted for vibratory pile driving (versus the static method applied in the proposed rule).
JASCO’s Animal Simulation Model Including Noise Exposure (JASMINE) was used to estimate
the closest approach ranges within which 95 percent of simulated animals (animats) were
exposed above the relevant regulatory-defined thresholds for injury and behavioral response for
marine species that may be near, or in the vicinity of, the proposed foundation piling operations
(impact and vibratory). Therefore, JASMINE was used to estimate the probability of exposure of
animals to sound arising from impact and vibratory pile driving operations during construction of
the Project. Sound exposure models such as JASMINE use simulated animals (animats) to
sample the predicted 3-D sound fields with movement rules derived from animal observations.
The parameters used for forecasting realistic behaviors (e.g., diving, foraging, aversion, and
surface times) are determined and interpreted from marine species studies (e.g., tagging studies)
where available, or reasonably extrapolated from related species (appendix G.2, Hydroacoustic
Report January 2024).
The predicted sound fields were sampled by the model receiver in a way that real animals
are expected to by programming animats to behave like marine species that may be present near
the Project. The output of the simulation is the exposure history for each animat within the
simulation. An individual animat’s sound exposure level is summed over a specified duration,
(i.e., 24 hours (appendix H Hydroacoustic Report January 2024)), to determine its total received

acoustic energy (SEL) and maximum received PK and SPL. Received levels are then compared
to the threshold criteria described in Section 2.4 (Hydroacoustic Report January 2024) within
each analysis period. Appendix H of the Hydroacoustic Report January 2024 provides a fuller
description of animal movement modeling and the parameters used in the JASMINE simulations.
Due to shifts in animal density and seasonal sound propagation effects, the number of animals
predicted to be impacted by the pile driving operations is sensitive to the number of foundations
installed during each month.
The animal movement modeling assumed 60 minutes of vibratory setting of piles for all
pile types and installation schedules. For piling of monopile foundations, the model assumed 15
minutes between vibratory and impact pile driving to switch equipment. A strike rate of 30
strikes per minute for the 5,000 kJ hammer scenarios, 27.6 strikes per minute for the 6,000 kJ
hammer 13 m monopile scenarios, and 25 strikes per minute for the 6,000 kJ hammer 12 m
monopile scenarios was used. The model assumed 30 minutes between foundation installation
when more than one foundation was installed per day.
For jacket foundations, the number of strikes required to drive each pile as provided by
Avangrid is a conservative estimate, in that it is likely to be an overestimate of the actual number
of strikes required. The animal movement modeling is based on exposure levels in a 24 hour
period to capture 24-hour cumulative metrics (i.e., SEL), so pile installation is constrained to fit
within 24 hours. To accommodate the high number of strikes for jacket foundations within a 24hour period, a strike rate of 30 per minute was used to model cases where 4 pin piles were
installed in one day. Additionally, the time between pile installation each day was 15 minutes
between vibratory and impact pile driving to switch equipment and 15 minutes between
foundation installations.
When evaluating the potential for injury, the total received acoustic energy (SEL) over a
given time period (24 hour) is needed. Vibratory setting of piles followed by impact pile driving
may occur for the installation of both monopile and jacket foundations. Although the potential to

induce hearing loss is low during vibratory driving, it does introduce sound into the water and
must be considered as part of the total received acoustic energy. For this reason, the combined
sound energy from vibratory and impact pile driving was computed in the 2024 January
Application Update from Avangrid. The PTS onset SEL thresholds are lower for impact piling
than for vibratory piling (section 2.4 Hydroacoustic Report January 2024), so when estimating
animats exposed to potentially injurious sound levels, the lower thresholds were applied to the
total received sound energy level from both sources. Full details on the acoustic model can be
found on our website in the Hydroacoustic Report January 2024 at
https://www.fisheries.noaa.gov/action/incidental-take-authorization-park-city-wind-llcconstruction-new-england-wind-offshore-wind.
As previously described, JASCO integrated the results from acoustic source and
propagation modeling into an animal movement model to calculate exposure ranges for 17
marine mammal species considered common in the project area. The resulting ranges represent
the distances at which marine mammals may incur Level A harassment (i.e., PTS). The exposure
ranges also influence the development of mitigation and harassment zone sizes. The first year of
Schedule A includes the potential installation of 13-m monopiles using a 6,000 kJ hammer. In
the proposed rule and unchanged in this final rule, this specific configuration was not modeled
beyond acoustic source modeling because initial source modeling showed minimal difference
between the 12-m and 13-m monopiles (see table 12 in the proposed rule (88 FR 37606, June 8,
2023)). Therefore, Avangrid modeled the 12-m monopile with 6,000 kJ hammer energy which
was assumed to be a reasonable replacement for the 13-m. Avangrid assumed that all phase 2
foundations are jackets as their modeling results found that jacket foundations are the most
impactful in terms of the Level A cumulative sound exposure metric. Thus, the assumption of all
jacket foundations provide an envelope for an up to 13-m monopile installed with a 5,000 or
6,000 kJ hammer. Tables 13 and 14 provide exposure ranges for impact pile driving 12-m and
13-m monopiles and 4-m pin piles (jacket foundations), assuming 10 dB of attenuation. Table 15

provides Level A harassment exposure ranges for vibratory pile driving followed by impact pile
driving of 12-m and 13-m monopiles, assuming 10 dB of attenuation. Table 16 provides Level B
harassment exposure ranges for vibratory pile driving followed by impact pile driving of 12-m
and 13-m monopiles, assuming 10 dB of attenuation. Table 17 provides exposure ranges for
vibratory pile driving followed by impact pile driving of 4-m pin piles (jacket foundations),
assuming 10 dB of attenuation.
Animat exposure modeling was not conducted for drilling. Instead, exposures were
calculated for one day of drilling, modeled at three site locations. Exposures were calculated for
each of these locations individually and for the maximum potential exposures using the
maximum ensonified area for each threshold. Exposures were estimated using the monthly
animal densities from May to December.

Table 13 – Exposure Ranges (ER95%, km) to Marine Mammal Level A Harassment (SEL) and Level B Harassment Thresholds During
Impact Pile Driving 12-m and 13-m Monopiles, Assuming 10 dB Attenuation1
Level A Harassment
Marin
e
Mam
mal
Specie
s

12-m Monopile

Level B Harassment

13-m Monopile

12-m Monopile

13-m Monopile

5,000 kJ
hammer (km)

6,000 kJ
hammer (km)

5,000 kJ
hammer (km)

6,000 kJ
hammer (km)

5,000 kJ
hammer (km)

6,000 kJ
hammer (km)

5,000 kJ
hammer (km)

6,000 kJ
hammer (km)

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

North
Atlant
ic
right
whale

1.19

1.41

1.19

1.34

1.19

1.37

1.56

1.62

4.50

4.39

4.91

4.83

4.73

4.51

5.28

5.18

Fin
whale

2.00

2.13

2.05

2.16

2.04

2.30

2.14

2.58

4.88

4.92

5.28

5.29

5.08

4.99

5.56

5.40

Hump
back
whale

1.71

1.78

1.72

1.97

1.87

1.99

1.96

1.99

4.86

4.65

5.26

5.12

5.02

4.93

5.27

5.40

Minke
whale

0.82

0.96

0.91

1.12

0.96

1.02

1.22

1.19

4.61

4.32

4.95

4.87

4.44

4.67

5.05

5.05

Sei
whale

0.94

1.14

1.36

1.27

1.17

1.30

1.32

1.31

4.72

4.60

5.19

5.17

4.96

4.90

5.44

5.34

Sperm
whale

0

0

0

0

4.68

4.51

5.22

5.16

4.80

4.84

5.33

5.27

Atlant
ic
spotte
d

0

0

0

0

4.48

4.18

5.02

4.51

4.74

4.58

4.88

4.84

dolphi
n
Atlant
ic
whitesided
dolphi
n

0

0

0

0

4.26

4.31

4.87

4.83

4.50

4.47

5.01

4.98

Bottle
nose
dolphi
n,
offsho
re

0

0

0

0

3.98

3.79

4.45

4.18

4.09

4.12

4.70

4.65

Com
mon
dolphi
n

0

0

0

0

4.47

4.34

4.99

4.88

4.63

4.55

5.28

5.10

Longfinned
pilot
whale

0

0

0

0

4.20

4.09

4.75

4.72

4.39

4.38

4.95

4.76

Shortfinned
pilot
whale

0

0

0

0

0

0

0

0

Risso’
s
dolphi
n

0

0

0

0

4.30

4.20

4.72

4.74

4.55

4.50

4.93

5.05

Harbo
r

0

0

0

0

4.23

3.94

4.46

4.44

4.49

4.41

4.74

4.75

porpoi
se
Gray
seal

0

0

0

0

5.10

5.13

5.58

5.53

5.42

5.34

5.85

5.77

Harbo
r seal

0

0

0

0

3.80

4.06

4.45

4.41

4.33

4.18

4.43

4.56

Harp
seal

0

0

0

0

4.86

4.84

5.26

5.31

5.02

4.96

5.50

5.45

1 – The exposure ranges presented here represent the assumption that the pile would be fully installed with an impact hammer.
Table 14 – Exposure Ranges (ER95%, km) to Marine Mammal Level A Harassment (SEL) and Level B Harassment Thresholds During
Impact Pile Driving Four 4-m Pin Piles per Day using a 3,500 kJ Hammer, Assuming 10 dB Attenuation1
Marine Mammal Species

Level A Harassment

Level B Harassment

North Atlantic right whale

2.35

4.54

Fin whale

3.73

4.66

Humpback whale

2.94

4.65

Minke whale

1.76

4.24

Sei whale

2.10

4.52

Sperm whale

4.52

Atlantic spotted dolphin

4.47

Atlantic white-sided dolphin

4.40

Bottlenose dolphin, offshore

4.02

Common dolphin

4.48

Long-finned pilot whale

4.11

Short-finned pilot whale

0

Risso’s dolphin

4.31

Harbor porpoise

4.20

Gray seal

0.79

4.97

Harbor seal

0.02

4.09

Harp seal

0.11

4.65

1 – The exposure ranges presented here represent the assumption that the pile would be fully installed with an impact hammer.
Table 15 – Exposure Ranges (ER95%, km) to Marine Mammal Level A Harassment (SEL) Thresholds During Vibratory Pile Setting
Followed by Impact Pile Driving for 12-m and 13-m Monopiles, Assuming 10 dB Attenuation1
Vibratory + Impact Pile Driving
Vibratory Only2
12-m Monopile
13-m Monopile
12-m Monopile
13-m Monopile
Marine
5,000 kJ hammer 6,000 kJ hammer 5,000 kJ hammer 6,000 kJ hammer 5,000 kJ hammer 6,000 kJ hammer 5,000 kJ hammer 6,000 kJ hammer
Mamma
(km)
(km)
(km)
(km)
(km)
(km)
(km)
(km)
l
two
two
two
two
two
two
two
two
Species one
one
one
one
one
one
one
one
piles/da
piles/da
piles/da
piles/da
piles/da
piles/da
piles/da
piles/da
pile/day
pile/day
pile/day
pile/day
pile/day
pile/day
pile/day
pile/day
y
y
y
y
y
y
y
y
North
Atlantic
1.15
0
1.39
1.44
1.29
1.40
1.54
1.59
0
0
0
0
0
0
0
0
right
whale
Fin
2.02
0.02
2.14
2.24
2.10
2.61
2.16
2.69
0.02
0
0.02
0
0
0
0
0
whale
Humpba
ck
1.72
0
1.88
1.98
1.90
2.05
1.94
2.07
0
0
0
0
0
0
0
0
whale
Minke
0.81
0
1.02
1.21
0.95
0.99
1.20
1.18
0
0
0
0
0
0
0
0
whale
Sei
1.15
0
1.64
1.26
1.23
1.30
1.27
1.33
0
0
0
0
0
0
0
0
whale
Sperm
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
whale
Atlantic
spotted
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
dolphin

Atlantic
white0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
sided
dolphin
Bottleno
se
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
dolphin,
offshore
Commo
n
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
dolphin
Risso’s
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
dolphin
Longfinned
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
pilot
whale
Shortfinned
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
pilot
whale
Harbor
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
porpoise
Gray
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
seal
Harbor
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
seal
Harp
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
seal
1 – The exposure ranges presented here represent the assumption that the pile would be partially installed using vibratory pile driving before the
remainder is installed with an impact hammer.
2 – Vibratory only is included to show that the distance to injury is small, however, no pile will be installed using only vibratory pile driving. Due to
Avangrid’s updated model approach, the combination of vibratory and impact pile driving within the model obscures the true distance to Level A
harassment during vibratory pile driving when combined with impact. Therefore, the Level A harassment column of vibratory + impact pile driving
is primarily a result of impact pile driving in the new model approach.

Table 16 – Exposure Ranges (ER95%, km) to Marine Mammal Level B Harassment Thresholds During Vibratory Pile Setting Followed by
Impact Pile Driving for 12 and 13-m Monopiles, Assuming 10-dB Attenuation1
Vibratory Only2

Impact Pile Driving
Marin
e
Mam
mal
Specie
s

12-m Monopile

13-m Monopile

12-m Monopile

13-m Monopile

5,000 kJ
hammer (km)

6,000 kJ
hammer (km)

5,000 kJ
hammer (km)

6,000 kJ
hammer (km)

5,000 kJ
hammer (km)

6,000 kJ
hammer (km)

5,000 kJ
hammer (km)

6,000 kJ
hammer (km)

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

one
pile/d
ay

two
piles/d
ay

North
Atlant
ic
right
whale

4.49

4.38

4.91

4.83

4.58

4.52

5.08

5.11

20.96

21.10

20.96

21.10

28.07

27.45

28.07

27.45

Fin
whale

4.97

4.89

5.30

5.31

5.12

4.97

5.59

5.49

22.22

22.14

22.22

22.14

29.40

29.41

29.40

29.41

Hump
back
whale

4.83

4.73

5.35

5.18

5.09

4.95

5.42

5.43

22.26

22.28

22.26

22.28

29.27

29.03

29.27

29.03

Minke
whale

4.49

4.43

5.01

4.92

4.62

4.75

5.19

5.21

22.06

21.93

22.06

21.93

28.66

28.38

28.66

28.38

Sei
whale

4.60

4.63

5.21

5.24

4.85

5.02

5.38

5.43

22.30

22.08

22.30

22.08

29.29

29.02

29.29

29.02

Sperm
whale

4.68

4.59

5.17

5.11

4.87

4.86

5.40

5.28

21.97

21.95

21.97

21.95

29.15

28.87

29.15

28.87

Atlant
ic
spotte
d

4.80

4.22

5.17

4.71

4.66

4.68

5.05

4.90

23.35

23.10

23.35

23.10

29.75

30.12

29.75

30.12

dolphi
n
Atlant
ic
whitesided
dolphi
n

4.32

4.40

5.08

4.97

4.50

4.57

5.04

5.03

22.07

21.72

22.07

21.72

28.30

28.64

28.30

28.64

Bottle
nose
dolphi
n,
offsho
re

4.03

3.71

4.29

4.41

4.15

4.12

4.61

4.76

21.21

20.81

21.21

20.81

27.88

27.42

27.88

27.42

Com
mon
dolphi
n

4.44

4.34

5.02

4.90

4.61

4.64

5.28

5.19

21.97

21.89

21.97

21.89

29.10

28.53

29.10

28.53

Longfinned
pilot
whale

4.21

4.20

4.86

4.76

4.50

4.48

4.84

4.83

21.72

21.59

21.72

21.59

27.77

27.45

27.77

27.45

Shortfinned
pilot
whale

0

0

0

0

0

0

0

0

Risso’
s
dolphi
n

4.42

4.27

4.78

4.71

4.60

4.59

4.99

5.08

21.05

20.79

21.05

20.79

27.16

27.41

27.16

27.41

Harbo
r

4.29

3.99

4.56

4.38

4.41

4.37

4.82

4.84

19.32

19.03

19.32

19.03

23.33

23.20

23.33

23.20

porpoi
se
Gray
seal

5.16

5.13

5.67

5.53

5.42

5.34

5.83

5.78

22.32

22.29

22.32

22.29

29.51

29.53

29.51

29.53

Harbo
r seal

3.81

4.03

4.35

4.42

4.33

4.15

4.56

4.69

19.80

19.89

19.80

19.89

24.96

24.58

24.96

24.58

Harp
seal

5.03

4.90

5.25

5.24

5.11

4.98

5.49

5.48

22.45

22.43

22.45

22.43

29.45

29.44

29.45

29.44

1 – The exposure ranges presented here represent the assumption that the pile would be partially installed using vibratory pile driving before the
remainder is installed with an impact hammer.
2 – No pile will be installed using only vibratory pile driving. Due to Avangrid’s updated model approach, the combination of vibratory and impact
pile driving within the model results in similar values for impact pile driving during vibratory as compared to impact only piles.
Table 17 – Exposure Ranges (ER95%, km) to Marine Mammal Level A Harassment (SEL) and Level B Harassment Thresholds During
Vibratory Pile Setting Followed by Impact Pile Driving for Four 4-m Pin Piles per Day using a 3,500 kJ Hammer, Assuming 10 dB
Attenuation1
Marine Mammal Species

Level A Harassment

Level B Harassment

Vibratory + Impact

Vibratory Only

Impact

Vibratory Only

North Atlantic right whale

2.44

4.47

25.66

Fin whale

4.02

0.04

4.63

27.74

Humpback whale

3.32

4.70

27.43

Minke whale

1.94

4.22

26.94

Sei whale

2.16

4.56

28.05

Sperm whale

0

4.54

27.11

Atlantic spotted dolphin

0

4.50

29.06

Atlantic white-sided
dolphin

0

4.41

27.16

Bottlenose dolphin,
offshore

0

Common dolphin

Long-finned pilot whale

4.09

25.85

4.46

27.04

0

4.18

26.89

Short-finned pilot whale

0

0

Risso’s dolphin

0

4.30

26.51

Harbor porpoise

0

4.21

23.26

Gray seal

0.79

4.98

27.41

Harbor seal

0.07

4.11

23.55

Harp seal

0.12

4.64

27.65

1 – The exposure ranges presented here represent the assumption that the pile would be partially installed using vibratory pile driving before the
remainder is installed with an impact hammer.

JASCO also calculated acoustic ranges which represent distances to NMFS’s harassment
isopleths independent of movement of a receiver. Acoustic ranges are a better representation of
distances to NMFS’s instantaneous harassment thresholds (i.e., PTS dB peak, and Level B
harassment) and can also be used for PTS dB SEL when animal movement modeling is not
conducted. As described previously, the distances to the PTS dB SEL threshold are likely an
overestimate as it assumes an animal remains at the distance for the entire duration of pile
driving. Presented below are the distances to the PTS (dB peak) threshold and Level B
harassment (SPL) thresholds for drilling.
Acoustic modeling assumed that drilling activity could occur for a full 24 hours during
any given day. Although drilling is not expected to be required for 24 hours, all modeling
assumed 24 hours of drilling to provide the most conservative estimate. Exposures were
calculated for one day of drilling. Drilling was modeled at each of the three model site locations
(J1, M1, M2). Exposures were calculated for each of these locations individually and also for the
maximum potential exposures using the maximum ensonified area for each threshold. Exposures
were estimated using the monthly animal densities from May to December. Maximum predicted
injury exposures were <0.01 for modeled marine mammals (see appendix K of the
Hydroacoustic Report January 2024), where ranges to injurious thresholds are <200 m for all
species.
Acoustic ranges to the Level A harassment threshold and Level B harassment thresholds
are in tables 18 and 19, respectively. Mean monthly density estimates for pile driving and
drilling, in consideration of the applicable perimeter for each type, are provided in tables 7, 8,
and 9.

Table 18 – Acoustic Ranges (R95%), in Km, to Level A Harassment Thresholds During Pile Driving and Drilling, Assuming 10 dB
Attenuation
Pile
Installed

Install
Method

Hammer
Energy (kJ)

Drilling

Drilling

N/A

12-m

Impact

12-m

Activity
Duration
(minutes)

Low-frequency cetacean

Mid-frequency cetacean

High-frequency cetaceans

Phocids

Lpk

SEL

Lpk

SEL

Lpk

SEL

Lpk

SEL

1,440 (24
hours)

-

0.065

-

0.0154

-

.057

-

0.1059

5,000

N/A

-

3.5

-

-

0.20

-

-

0.40

Impact

6,000

N/A

-

3.546

-

-

0.24

0.02

-

0.40

13-m

Impact

5,000

N/A

-

4.0

-

-

0.25

0.09

-

0.44

13-m

Impact

6,000

N/A

-

4.041

-

-

0.28

0.108

-

0.451

4-m

Impact

3,500

N/A

-

6.822

-

-

0.17

0.428

-

1.605

12-m

Impact +
Vibratory

5,000

N/A

-

3.67

-

-

-

-

-

0.42

12-m

Impact +
Vibratory

6,000

N/A

-

4.08

-

-

-

0.4

-

0.49

13-m

Impact +
Vibratory

5,000

N/A

-

4.12

-

-

-

0.09

-

0.45

13-m

Impact +
Vibratory

6,000

N/A

-

4.58

-

-

-

0.11

-

0.53

4-m

Impact +
Vibratory

3,500

N/A

-

7.41

-

-

-

0.44

-

1.74

N/A

0.20

-

-

-

-

-

-

12-m

Vibratory

13-m

Vibratory

N/A

0.15

-

-

-

-

-

-

4-m

Vibratory

N/A

1.13

-

-

-

-

-

-

Note: Values are from the Hydroacoustic Report January 2024.

Table 19 – Acoustic Ranges (R95%), in Meters, to Level B Harassment Thresholds During
Pile Driving and Drilling, Assuming 10 dB Attenuation
Pile Installed

Install Method

Distance to Level B harassment
(km)

Drilling

Drilling

7.054

12-m (5,000 kJ)

Impact

5.07

12-m (6,000 kJ)

Impact

5.456

13-m (5,000 kJ)

Impact

5.39

13-m (6,000 kJ)

Impact

5.716

4-m (3,500 kJ)

Impact

5.016

12-m

Vibratory

22.521

13-m

Vibratory

28.900

4-m

Vibratory

27.896

Unchanged from the proposed rule, to estimate take from foundation installation
activities, Avangrid used two pile installation construction schedules (tables 20 and 21). Overall,
Construction Schedule A (Schedule A) assumes 52 days of foundation installation activities
would occur between May and December in 2026 (year 2) to install 89 monopiles and 2 jacket
foundations and 35 days of foundation installation activities would occur in 2027 (year 3) to
install 18 monopiles and 24 jacket foundations. As previously described, Park City accounted for
133 piles to be installed in its modeling despite a maximum of 132 foundations actually being
installed. In total, based on Schedule A, 87 days of foundation installation activities would occur
over 2 years to complete the Project. Construction Schedule B (Schedule B) assumes 38 days of
foundation installation activities would occur between May and December in 2026 (year 2) to
install 55 monopiles and 3 jacket foundations, 53 days of foundation installation activities would
occur in 2027 (year 3) to install 53 jackets, and 22 days of foundation installation activities
would occur in 2028 (year 4) to install 22 jackets. In total, based on Schedule B, 113 days of
foundation installation activities would occur over 3 years to complete the Project.
Due to the extended duration of Schedule B, the total amount of Level B harassment from
foundation installation activities is greater than Schedule A over the 5-year effective period of

the final rule. The total 5-year take by Level B harassment in this final rule is therefore generated
based on Schedule B. However, annual take estimates assume the yearly worst case scenario
exposures for each species for each year from either Construction Schedule A or B. That is,
annual take by Level B harassment due to foundation installation activities may use either
Schedule A or B, whichever was more. As previously described, Park City accounted for 133
piles to be installed in its modeling despite a maximum of 132 foundations actually being
installed to complete the Project.
Avangrid considered three foundation installation techniques when estimating take:
impact pile driving, vibratory pile driving followed by impact pile driving, and drilling (to break
up any obstacles should the pile encounter obstructions). Of these, Level A harassment (PTS) has
the potential to occur from impact pile driving only. As shown in table 18, vibratory pile driving
and drilling produce very small Level A harassment zone sizes that consider static receivers over
the duration of the time period considered in the model. For vibratory pile driving, the duration
considered was relatively short (60 minutes); however, this represents vibratory pile driving over
two piles in which there are several hours in between events and the resulting distances are
comparatively small (table 18). Moreover, the implementation of clearance and shut down zones
would further reduce the potential for PTS from these activities. Therefore, Avangrid has
concluded, and NMFS agrees, the potential for PTS to occur from vibratory pile driving or
drilling is discountable. For this reason, Avangrid carried forward the PTS exposure estimates
from impact pile driving and no take by Level A harassment was considered for vibratory pile
driving or drilling. The maximum take by Level A harassment that may be authorized under this
final rule from the foundation activities (i.e., impact pile driving) is in table 24.
To estimate the amount of Level B (behavioral) harassment that may occur incidental to
foundation installation, Avangrid considered all three installation methods. As described above,
Avangrid conducted exposure modeling to estimate the number of exposures that may occur
from pile driving. The results of the exposure modeling and amount of take Avangrid requested

from this activity is provided in the January 2024 Application Update. Avangrid calculated take
considering drilling for 48 foundations over 48 days for both Schedule A and Schedule B. In the
proposed rule and unchanged in the final rule, Avangrid applied a more traditional approach to
estimate take from drilling wherein:
Take = density x area ensonified x number of days of activity
The resulting monthly and annual take can be found in the January 2024 Application
Update.
To avoid overestimating take, the amount of take derived when considering impact
driving, vibratory driving, and drilling independently were not summed to produce the amount of
annual take Avangrid requested. Instead, Avangrid appropriately deducted the take from drilling
when vibratory pile driving and drilling would occur on the same day. This is because the area
for vibratory pile driving is much larger than drilling (table 19) and the amount of take by Level
B harassment estimated for vibratory pile driving adequately covers potential take from drilling
activities. However, because take from pile driving was modeled based on the number of piles
while drilling takes were based on the number of days of activity, Avangrid added the take
estimates from pile driving all piles to the take estimates from vibratory drilling (with the
appropriate discounting) to produce their annual and total take requests.
The amount of Level B harassment take that may be authorized by this final rule
represents the amount of take from impact pile driving on days when only impact pile driving
could occur plus the amount of take from vibratory pile driving or drilling on the days that either
of those activities could occur to avoid double counting.
Table 24 provides the annual take by Level B harassment calculated from pile driving for
both Schedule A and, separately, Schedule B. For ease of reference, the construction schedules
have been included below in tables 20-21. Table 25 identifies the amount of take for drilling
foundation installation activities after removing drilling takes when drilling would occur on the
same day as vibratory pile driving (to avoid double counting). The annual take amounts represent

the highest value between both Schedule A and Schedule B while the maximum 5-year take
estimates represent the sum of take calculated for each year in Schedule B (as Schedule B has the
highest amount of take associated). NMFS retained Avangrid’s request for Level A harassment
from all impact pile driving activities as no Level A harassment from vibratory pile driving or
drilling is anticipated (table 24). Table 26 identifies the amount of take for all foundation
installation activities combined that was carried forward in the take tables for this final rule.

Table 20 – Pile Installation Construction Schedule A Year 2 and 3.
Year 2 (2026) a
4m
Total
Pin pile Total
days
Days
3,500 kJ days of
Month
with
impact
with
vibratory
only
drilling c
+ impact
1 per day 2 per day 1 per day 2 per day 4 per day piling
piling b
12 m Monopile
5,000 kJ

13 m Monopile
5,000 kJ

Year 3 (2027)
Year 2
4 m Pin
Total
12 m Monopile
Total
Total
Pile
days
6,000 kJ
days of
3,500 kJ days of
with Days with
foundatio
impact
vibratory drilling c
n
only
+ impact
Installati 1 per day 2 per day 1 per day piling
piling b
c
on

Year 3
Total
days of
foundatio
n
Installati
on c

May
4
0
0
0
0
4
0
2
4
4
0
0
4
0
1
4
June
2
5
0
0
0
5
2
4
7
0
3
0
1
2
2
3
July
0
9
0
0
0
5
4
7
9
0
4
0
0
4
2
4
August
0
9
0
0
0
3
6
7
9
0
0
8
0
8
4
8
Septemb
0
1
1
6
2
6
4
8
10
0
0
7
1
6
2
7
er
October
0
0
0
6
0
3
3
3
6
0
0
6
2
4
2
6
Novemb
0
0
0
3
0
2
1
2
3
0
0
2
1
1
2
2
er
Decembe
0
0
4
0
0
4
0
0
4
0
0
1
1
0
0
1
r
Total
6
24
5
15
2
32
20
33
52
4
7
24
10
25
15
35
Total
Annual
52 days
35 days
Days
Total
Annual
89 monopiles and 2 jackets
18 monopiles and 24 jackets
Foundati
ons
Total
Annual
89 monopiles and 8 pin piles
18 monopiles and 96 pin piles
Piles
Total
Schedule
87
Days
Total
Schedule
113
Foundati
ons
Total
Schedule
211
Piles
a – The request is for the 5-year period 2025–2029, during which pile installation is scheduled to begin in 2026. These dates reflect the currently projected construction start
year and are subject to change because exact project start dates and construction schedules are not currently available. No concurrent/simultaneous pile driving of
foundations is planned.

b – The number of days with vibratory hammering or drilling is based on a percentage of the number of days of pile installation and includes installation of a mix of
monopiles at a rate of both one per day and two per day as well as installation of jacket foundations at a rate of four pin piles per day. The number of takes by Level B
harassment per day is unaffected by the number of piles or foundations installed on that day because the SPL 120 dB metric is not cumulative. Level B take was estimated
using density-based calculations that assume all animals within the area ensonified to 120 dB are taken as soon as the activity begins and cannot be taken additional times
within one day. Only Level B takes are being requested for drilling and vibratory hammering.
c – Avangrid assumed that vibratory hammering and drilling would not occur on the same day, when possible. However, for months when the number of days with vibratory
hammering plus the number of days with drilling exceeded the total number of impact piling days that month, and assumed the minimum number of days of overlap possible
for these two activities. On the days with overlap between drilling and vibratory hammering, the estimated Level B takes resulting from drilling were not included to avoid
double counting taken animals, because all animals within the larger vibratory hammering zone of influence were assumed to have already been taken by that activity. Level
B takes for 8 days of drilling in year 2 (2026) and 9 days of drilling in year 3 (2027) shown in Schedule A were thus not included in the total take estimates.

Table 21 – Pile Installation Construction Schedule B Year 2, 3, and 4.
Year 2 (2026)a

Year 3 (2027)

Year 2
4m
4m
Total
Total Pin pile
Pin pile Total
days
Days days of 3,500 kJ
3,500 kJ days of
Month
with
impact
with foundati
vibratory
only
drilling c
on
+ impact
1 per day 2 per day 4 per day piling
4 per day
installati
piling b
on c
12 m Monopile
5,000 kJ

May
June
July
August
Septemb
er
October
Novemb
er
Decembe
r
Total
Total
Annual
Days
Total
Annual
Foundati
ons
Total
Annual
Piles

Year 4 (2028)

Year 3
4m
Total
Total
Total Pin pile
days
days of
Days days of 3,500 kJ
with
impact
with foundati
vibratory
only
drilling c
on
4 per
+ impact
piling
installati
day
piling b
c
on

Year 4
Total
Total
Total
days
days of
Days days of
with
impact
with foundati
vibratory
only
drilling c
on
+ impact
piling
installati
piling b
on c

4
6
0
0
4
7
0
0
0
4
8
3
0
2
4
2
4
3
4
10
7
1
9
14
1
7
9
0
2
5
1
4
4
1
9
14
1
4
5
1
2
3
0
2
2
1
2
2
1
4
5
0

1

4

4

3

4

5

1

5

1

0

2

4

4

4

0

1

2

0

1

2

1

1

1

1

1

0

1

0

1

0

1

0

0

15

3

20

38

28

19

22

9

22

38 days

53 days

22 days

55 monopiles and 3 jackets

53 jackets

22 jackets

55 monopiles and 12 pin piles

212 pin piles

88 pin piles

Total
Schedule
113
Days
Total
Schedule
133
Foundati
ons
Total
Schedule
367
Piles
a – This LOA request is for the 5-year period 2025–2029, during which pile installation is scheduled to begin in 2026. These dates reflect the currently projected
construction start year and are subject to change because exact project start dates and construction schedules are not currently available. No concurrent/simultaneous pile
driving of foundations is planned.
b – The number of days with vibratory hammering or drilling is based on a percentage of the number of days of pile installation and includes installation of a mix of
monopiles at a rate of both one per day and two per day as well as installation of jacket foundations at a rate of four pin piles per day. The number of takes by Level B
harassment per day is unaffected by the number of piles or foundations installed on that day because the SPL 120 dB metric is not cumulative. Level B take was estimated
using density-based calculations that assume all animals within the area ensonified to 120 dB are taken as soon as the activity begins and cannot be taken additional times
within one day. Only Level B takes are being requested for drilling and vibratory hammering.
c – As a conservative measure, it was assumed that vibratory hammering and drilling would not occur on the same day, when possible. However, for months when the
number of days with vibratory hammering plus the number of days with drilling exceeded the total number of impact piling days that month, and assumed the minimum
number of days of overlap possible for these two activities. On the days with overlap between drilling and vibratory hammering, the estimated Level B takes resulting from
drilling were not included to avoid double counting taken animals, because all animals within the larger vibratory hammering zone of influence were assumed to have
already been taken by that activity. Level B takes for 9 days of drilling in year 2 (2026), 2 days of drilling in year 3 (2027), and 2 days of drilling in year 4 (2028) shown in
Schedule B were thus not included in the total take estimates.

Table 22 – Marine Mammal Exposure Estimates for Construction Schedule A and Schedule B for Impact and Vibratory Pile Driving,
Assuming 10 dB Noise Attenuationa
Schedule A
Species

Level A Harassment

Schedule B

Level B Harassment

Level A Harassment

Level B Harassment

Year 2

Year 3

Year 2

Year 3

Year 2

Year 3

Year 4

Year 2

Year 3

Year 4

North
Atlantic
right whale c

0.98

1.71

19.36

30.72

0.75

2.88

1.32

13.21

40.53

18.14

Fin whale b

5.57

7.75

108.46

152.41

4.24

19.32

7.79

91.43

188.88

67.19

Humpback
whale

5.58

8.04

75.24

98.79

3.99

16.51

7.10

62.63

127.85

55.43

Minke whale
(migrating)b

16.88

29.55

284.57

353.33

15.02

85.85

37.91

259.13

517.67

230.59

Sei whale
(migrating)b

0.54

1.25

12.02

18.61

0.41

2.36

1.14

8.99

26.18

13.57

0

28.33

47.71

0

23.63

54.21

17.44

Atlantic
spotted
dolphin

0

81.79

135.51

0

45.03

137.43

42.41

Atlantic
white sided
dolphin

0

951.70

1287.99

0

754.22

1838.83

832.54

Bottlenose
dolphin,
offshore

0

897.08

1663.50

0

656.25

2164.30

799.98

Common
dolphin

0

13739.47

23178.10

0

9842.10

28373.15

10590.19

Long-finned
pilot whale

0

105.51

164.14

0

79.13

210.13

78.75

Short-finned
pilot whale

0

0

0

0

0

Risso’s
dolphin

0

168.60

400.34

0

94.69

458.24

143.19

Harbor
porpoise
(sensitive)b

0

485.64

717.07

0

391.52

863.37

337.33

Gray seal

0.01

0.36

593.10

872.72

0.02

0.67

0.32

297.91

1181.15

555.33

Harbor seal

<0.01

0.07

333.67

461.08

<0.01

0.13

0.06

268.75

529.17

272.98

Harp seal

<0.01

0.33

715.48

1212.34

0.03

0.57

0.28

378.60

1674.77

786.14

Sperm whale
c

Note: Each construction schedule includes a combination of pile sizes (4, 12, and 13 m), foundation types (monopiles or jackets), and installation methods (either vibratory
setting of piles followed by impact pile driving or impact pile driving alone). Values in bold are changed from the proposed rule.
a – Density estimates are calculated from the 2022 Duke Habitat-Based Marine Mammal Density Models (Roberts et al., 2016; Roberts et al., 2022).
b – Listed as Endangered under the ESA.

Table 23 – Marine Mammal Exposure Estimates for Drilling During Construction Schedule A and Schedule B, Assuming 10 dB Noise
Attenuationa
Species

Schedule A

Schedule B

Year 2

Year 3

Year 2

Year 3

Year 4

North Atlantic right
whale c

2.59

1.32

1.97

1.44

0.98

Fin whale c

15.13

6.18

8.83

9.01

3.85

Humpback whale

10.23

4.75

6.74

6.16

3.20

Minke whale (migrating)b

38.79

16.85

27.73

25.30

12.87

Sei whale c (migrating)b

1.92

1.03

1.47

1.12

0.76

Sperm whale c

3.17

1.45

1.80

1.75

0.67

Atlantic spotted dolphin

7.42

3.43

4.19

3.51

1.73

Atlantic white sided
dolphin

93.80

43.60

63.53

56.43

30.47

Bottlenose dolphin,
offshore

77.19

34.63

45.58

44.48

19.90

Common dolphin

877.24

377.50

515.72

485.77

210.11

Long-finned pilot whale

10.16

4.62

6.16

5.85

2.77

Short-finned pilot whale

2.54

1.15

1.54

1.46

0.69

Risso’s dolphin

5.73

2.55

3.30

3.11

1.34

Harbor porpoise
(sensitive)b

71.60

34.46

50.91

39.30

24.34

Gray seal

33.81

19.32

27.62

19.27

14.80

Harbor seal

50.72

28.97

41.43

28.91

22.20

Harp seal

36.23

20.70

29.59

20.65

15.86

Note: No Level A harassment is expected or may be authorized for drilling. Drilling exposure estimates are based on the assumption that 48 days under either Schedule A
or Schedule B would require drilling. Estimated exposures are from the full drilling schedule; final take request does not include drilling exposures on days when both
vibratory setting and drilling occur on the same day to avoid double counting because all animals within the larger vibratory hammering zone of influence were assumed to

have already been taken by that activity. A total of 17 days (8 days in year 1, 9 days in year 2) of drilling exposures in Construction Schedule A were not included in the
final take request. A total of 13 days (9 in year 1, 2 in year 2, and 2 in year 3) of drilling exposures in Construction Schedule B were not included in the final take request.
a – Density estimates are calculated from the 2022 Duke Habitat-Based Marine Mammal Density Models (Roberts et al., 2016; Roberts et al., 2022).
b – Listed as Endangered under the ESA.

Table 24 – Maximum Annual Amount of Take That May Be Authorized by Level A and Level B Harassments From Pile Driving Associated
with WTG and ESP Total Installation Events for Construction Schedule A and B, Assuming 10 dB of Noise Attenuation
Species

Year 2 (2026)

Year 3 (2027)

Year 4 (2028)

Level A Harassment

Level B Harassment

Level A Harassment

Level B Harassment

Level A Harassment

Level B Harassment

North Atlantic right
whalea

18

39

17

Fin whale

100

181

64

Humpback whale

67

120

52

Minke whale

233

443

193

Sei whale

10

23

12

Sperm whale

26

52

17

Atlantic spotted
dolphin

78

136

42

Atlantic white sided
dolphin

794

1635

736

Bottlenose dolphin,
offshore

795

2007

738

Common dolphin

11613

25942

9664

Long-finned pilot
whale

92

193

72

Short-finned pilot
whale

9

9

9

Risso’s dolphin

159

446

139

Harbor porpoise

423

787

295

Gray seal

574

1172

550

Harbor seal

304

497

253

Harp seal

685

1647

770

Note: Schedule A has the maximum amount of take reasonably likely to occur in Y2 and Y3 while Schedule B has the maximum for Y4. Double counting of take has been
removed.
a – While exposures were estimated, the level of mitigation required for North Atlantic right whales results in take by Level A harassment to be unlikely to occur, hence, no
take by Level A harassment for North Atlantic right whales was requested nor would be authorized by NMFS.

Table 25 – Maximum Annual Amount of Take That May Be Authorized by Level B Harassment From Drilling Associated with WTG and
ESP Total Installation Events for Construction Schedule A and B, Assuming 10 dB of Noise Attenuation
Species

Year 2 (2026)

Year 3 (2027)

Year 4 (2028)

Level A Harassment

Level B Harassment

Level A Harassment

Level B Harassment

Level A Harassment

Level B Harassment

North Atlantic right
whale

3

2

1

Fin whale

11

9

4

Humpback whale

9

6

3

Minke whale

32

24

13

Sei whale

2

2

1

Sperm whale

3

2

1

Atlantic spotted
dolphin

7

3

1

Atlantic white sided
dolphin

80

50

24

Bottlenose dolphin,
offshore

57

40

16

Common dolphin

666

408

156

Long-finned pilot
whale

8

6

3

Short-finned pilot
whale

2

2

1

Risso’s dolphin

5

3

1

Harbor porpoise

60

36

20

Gray seal

33

19

12

Harbor seal

49

28

17

Harp seal

35

20

12

Note: Schedule A has the maximum amount of take reasonably likely to occur in Y2 and Y3 while Schedule B has the maximum for Y4. Take does not include level B
harassment from drilling on days when both vibratory setting and drilling occur on the same day to avoid double counting.

Table 26 – Annual Take, by Level A and Level B Harassments, That May Be Authorized for All Foundation Installation Activities for
Construction Schedule B, Assuming 10 dB of Noise Attenuationa
Impact and Vibratory Pile Driving
Year 2 (2026)

Species

Drilling

Year 3 (2027)

Year 4 (2028)

Year 2 (2026)

Year 3 (2027)

Year 4 (2028)

Level A
Harassment

Level B
Harassment

Level A
Harassment

Level B
Harassment

Level A
Harassment

Level B
Harassment

Level B
Harassment

Level B
Harassment

Level B
Harassment

North Atlantic
right whale

13

39

17

2

Fin whale

88

181

64

9

Humpback
whale

59

120

52

6

Minke whale

232

443

193

24

Sei whale

9

23

12

2

Sperm whale

23

52

17

2

Atlantic
spotted
dolphin

45

136

42

3

Atlantic white
sided dolphin

696

1635

736

50

Bottlenose
dolphin,
offshore

622

2007

738

40

Common
dolphin

9332

25942

9664

408

Long-finned
pilot whale

75

193

72

6

Short-finned
pilot whale

9

9

9

2

Rissos dolphin

92

446

139

3

Harbor
porpoise

363

787

295

36

Gray seal

286

1172

550

19

Harbor seal

253

497

253

28

Harp seal

361

1647

770

20

a – As construction Schedule B has the highest total take by harassment for foundation installation, this table represents the sum of the takes from Schedule B only and not
the sum of the preceding columns within the previous tables. Schedule B has been used to set the total 5-Y take amounts that may be authorized for Level B harassment.
Take does not include Level B harassment from drilling on days when both vibratory setting and drilling occur on the same day to avoid double counting.

UXO/MEC Detonations
Avangrid may detonate up to 10 UXO/MECs within the project area with no more than
six in 2025 (year 1) and four in 2026 (year 2); no more than one detonation per 24-hour period
would occur. Avangrid adopted the U.S. Navy’s charge weight bins (E4, E6, E8, E10, and E12)
to determine potential impacts to marine mammals from UXO/MEC detonation. As described in
the proposed rule, Avangrid applied modeling results from the Revolution Wind project to its
analysis. This modeling evaluated the effects thresholds for TTS, PTS, non-auditory injury, and
mortality based on the appropriate metrics: (1) peak sound pressure level; (2) weighted
cumulative SEL; and (3) acoustic impulse. Charge weights of 2.3 kg (5.1 pounds (lbs)), 9.1 kg
(20.1 lbs), 45.5 kg (100.3 lbs), 227 kg (500 lbs), and 454 kg (1,000.9 lbs), which is the largest
charge the Navy considers for the purposes of its analyses (see the Description of the Specified
Activities section in the proposed rule), were modeled to determine the ranges to mortality,
gastrointestinal injury, lung injury, PTS, and TTS thresholds. The exact type and net explosive
weight of UXO/MECs that may be detonated are not known at this time. However, based on the
results of a UXO/MECs desktop study (Mills, 2021), Avangrid does not expect that 10 of the
largest charge weight (bin E12) UXO/MECs will be present, but a combination of different sizes.
For the 10 UXO/MECs, the model estimated the E12 charge weight with 2 detonations at 12 m,
3 detonations at 20 m, 3 detonations at 30 m, and 2 detonations at 40 m.
Mortality and non-auditory injury to lung and gastrointestinal organs were considered in
the modeling study (Hannay and Zykov, 2022). As described in the proposed rule, peak pressure
and acoustic impulse levels and effects threshold exceedance zones depend only on charge
weight, water depth, animal mass, and submersion depth. The maximum distance to
gastrointestinal injury (1 percent of exposed animals) due to peak pressure for detonating an
E12-size UXO/MEC at all sites assuming 10 dB of attenuation is 125 m (Hannay and Zykov,
2022). The maximum distance modeled to the onset of lung injury due to detonating an E12-size
UXO/MEC assuming 10 dB of attenuation is 237 m for baleen whales, 330 m for pilot and

minke whales, 448 m for beaked whales, 606 m for delphinids, Kogia, and pinnipeds, and 648 m
for harbor porpoise (table 27). Assuming 10 dB of attenuation, the impulse-based maximum
distance to the onset of mortality is 353 m (porpoises) (table 27).
Table 27 – UXO/MEC Impulse Exceedance Distances (Meters) for Marine Mammals for
the Detonation of an E12 UXO/MEC, for Onset of Lung Injury and Mortality at Various
Depths Assuming 10 dB Attenuation
Marine
Mammal
Group

12 m Water Depth
Calf/Pup

Adult

20 m Water Depth
Calf/Pup

Adult

30 m Water Depth
Calf/Pup

45 m Water Depth

Adult

Calf/Pup

Adult

Onset of Lung Injury (m)
Baleen
whales
and
Sperm
whale

73

80

81

78

Pilot and
Minke
whales

103

126

131

132

Beaked
whales

171

237

267

282

Dolphins,
Kogia,
and
Pinnipeds

241

351

400

429

Porpoises

260

381

429

465

Onset of mortality (m)
Baleen
whales
and
Sperm
whale

34

34

31

29

Pilot and
Minke
whales

56

58

57

50

Beaked
whales

105

127

132

135

Dolphins,
Kogia,
and
Pinnipeds

154

198

211

224

Porpoises

167

215

231

243

Avangrid will be required to conduct extensive monitoring using both PSOs and PAM
operators and clear an area of marine mammals prior to detonating any UXO/MEC. Given that
Avangrid will be employing multiple platforms to visually monitor marine mammals as well as
conducting PAM and must only detonate UXO/MECs during daylight hours, it is reasonable to
conclude that marine mammals will be reliably detected within approximately 660 m of the
UXO/MEC being detonated and mortality or non-auditory injury is not likely to occur. As
described below, in consideration of the distances to the associated thresholds and the
implementation of the required mitigation and monitoring measures, Avangrid did not request
and NMFS does not anticipate and may not authorize take by mortality or non-auditory injury.
All modeling results, including mortality and non-auditory injury, can be found in appendix A
for Avangrid’s ITA application (Hannay and Zykov, 2022), as found on NMFS’ website
(https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-takeauthorizations-other-energy-activities-renewable).
Distances to PTS and TTS thresholds for all UXO/MEC charge weights were also
calculated by Avangrid. In the proposed rule, we only described the distances to thresholds for
the largest E12 charge weight. However, in the event that Avangrid will be able to identify and
mitigate at the relevant distances for each specific charge weight, we have incorporated the
maximum values for each charge weight size herein. It is not currently known how easily the
size and charge weights of UXO/MECs can be identified in the field. Avangrid must demonstrate
to NMFS that it is able to accurately identify charge weights in the field prior to detonation
otherwise the largest charge weight, E12, will be assumed and the appropriate associated
mitigation and monitoring measures implemented. Tables 28 and 29 contain the maximum
(ER95%) modeled distances by Hannay and Zykov (2022) to PTS and TTS thresholds during
UXO/MEC detonation for each charge weight bin.

Table 28 – Maximum SEL-based R95% PTS-Onset Ranges, in Meters, from all Site Modeled During UXO/MEC Detonation by Charge
Weight, Assuming 10-dB Sound Attenuation
Marine
Mammal
Hearing
Group

2.3 kg (5.1 lbs)

9.1 kg (20.1 lbs)

45.5 kg (100.3 lbs)

227 kg (500 lbs)

454 kg (1,000.9 lbs)

Rmaxa

R95%b

Rmax

R95%

Rmax

R95%

Rmax

R95%

Rmax

R95%

LFC

552

1,230

2,010

1,730

3,370

2,970

4,270

3,780

MFC

<50

<50

75

156

337

461

HFC

2,100

1,820

3,020

2,590

4,400

3,900

6,130

5,400

6,960

6,200

PP

182

357

690

1,410

1,220

1,830

1,600

Note: LFC = low-frequency cetaceans; MFC = mid-frequency cetaceans; HFC = high-frequency cetaceans; PP = phocid pinnipeds
a – Represents the maximum distance in any direction that the threshold was exceeded. This metric is often overly conservative for take estimates because it reflects the
influence of coherent constructive interference effects, produced by most propagation loss models, due to model approximations of highly uniform environments. In
practice, these coherent effects are almost always disrupted by rough interfaces and ocean inhomogeneities.
b – Represents the radius of a circle that encompasses 95 percent of the area predicted by the model to exceed the threshold. The circle radius is typically larger than the
maximum distances in most directions, but it cuts off “fingers” of ensonification that protrude in a small number of directions. This metric is typically also conservative,
but less so than the Rmax distance.

Table 29 – Maximum SEL-based R95% TTS-Onset Ranges, in Meters, from all Site Modeled During UXO/MEC Detonation by Charge
Weight, Assuming 10-dB Sound Attenuation
Marine
Mammal
Hearing
Group

2.3 kg (5.1 lbs)

9.1 kg (20.1 lbs)

45.5 kg (100.3 lbs)

227 kg (500 lbs)

454 kg (1,000.9 lbs)

Rmaxa

R95%b

Rmax

R95%

Rmax

R95%

Rmax

R95%

Rmax

R95%

LFC

3,140

2,820

5,230

4,680

8,160

7,490

11,700

10,500

13,500

11,900

MFC

453

773

1,520

1,240

2,400

2,120

2,930

2,550

HFC

6,920

6,160

8,970

8,000

11,300

10,300

14,600

12,900

15,600

14,100

PP

1,730

1,470

2,710

2,350

4,340

3,820

6,640

5,980

7,820

7,020

Note: LFC = low-frequency cetaceans; MFC = mid-frequency cetaceans; HFC = high-frequency cetaceans; PP = phocid pinnipeds
a – Represents the maximum distance in any direction that the threshold was exceeded. This metric is often overly conservative for take estimates because it
reflects the influence of coherent constructive interference effects, produced by most propagation loss models, due to model approximations of highly uniform
environments. In practice, these coherent effects are almost always disrupted by rough interfaces and ocean inhomogeneities.

b – Represents the radius of a circle that encompasses 95 percent of the area predicted by the model to exceed the threshold. The circle radius is typically larger
than the maximum distances in most directions, but it cuts off “fingers” of ensonification that protrude in a small number of directions. This metric is typically
also conservative, but less so than the Rmax distance.

To estimate the maximum ensonified zones that could result from UXO/MEC
detonations, the area distances in Li and Koessler (2022) table J-5 were multiplied by the highest
monthly species density in the deepwater OECC segment and the SWDA for the 20–45 m
depths, and by the highest monthly species density in the shallow water OECC segment for the
12 m depth. The result of the areas multiplied by the densities were then multiplied by the
number of UXO/MECs estimated at each of the depths to calculate total estimated exposures. To
calculate potential marine mammal exposures, Avangrid assumed all charge weights belong in
the largest E12 class; therefore, the largest acoustic range (R95%t; assuming 10 dB of attenuation)
to PTS and TTS thresholds of a E12 UXO/MEC charge weight were used as radii to calculate the
area of a circle (pi × r2; where r is the range to the threshold level) for each marine mammal
hearing group. The ensonified area distances were multiplied by the highest monthly species
density in the deepwater OECC segment and the lease area (SWDA) for the 20–45 m depths, and
by the highest monthly species density in the shallow water OECC segment for the 12 m depth
(using a 14.1-km buffer) and the combined deepwater segment of the OECC and SWDA (20 m –
45 m depths; using a 13.8-km buffer).
As a conservative approach, the month with the highest density among the areas of
interest for each species was carried forward to the exposure calculations (i.e., assumed all
UXO/MECs would be detonated in the month with the greatest average monthly density). In
some cases where monthly densities were unavailable, annual densities were used instead for
some species (i.e., blue whales, pilot whale spp.). Additionally, the pilot whale guild, harbor
seals, gray seals, and harp seals were scaled by relative abundance following the same approach
previously described. The resulting maximum density was multiplied by the number of
UXO/MECs estimated at each of the depths to calculate total estimated exposures. Table 30
provides the maximum species-specific densities for the Project and resulting take calculations
using the described approach. As described above, Avangrid based the amount of take requested

for authorization on the number of exposures estimated assuming 10 dB of attenuation using a
NAS, NAS would be required during all detonations.
The likelihood of marine mammal exposures above the PTS threshold is low, especially
considering the instantaneous nature of the acoustic signal and that Avangrid would conduct
extensive monitoring, delaying a detonation should a marine mammal be within the PTS
distances. However, some species, such as harbor porpoise and seals are difficult to detect given
the relatively large distances to the high-frequency cetacean Level A harassment (PTS, SELcum)
isopleth applicable to harbor porpoises and the difficulty detecting this species at sea, Avangrid
requested, and NMFS may authorize, takes by Level A harassment of harbor porpoise from
UXO/MEC detonations. Similarly, seals are difficult to detect at longer ranges, and although the
distance to the phocid hearing group SEL PTS threshold is not as large as those for highfrequency cetaceans, it may not be possible to detect all seals within the PTS threshold distances
even with the required monitoring measures. Therefore, Avangrid requested and NMFS may
authorize under this rulemaking take by Level A harassment of gray seals, harbor seals, and harp
seals incidental to UXO/MEC detonation. Given the extensive monitoring, it is likely that all
PTS of large whales would be avoided. However, in the unexpected circumstance that a large
whale other than a North Atlantic right whale (i.e., fin whale, humpback whale, minke whale,
sei, and sperm whales) is missed during monitoring, Avangrid requested, and NMFS may
authorize, a very small amount of Level A harassment incidental to UXO/MEC detonation. Due
to the mitigation and monitoring measures required specifically for North Atlantic right whales
(e.g., clearance zone is “any distance”; table 36), it is unlikely that North Atlantic right whales
will be missed during monitoring. Therefore, take by Level A harassment is not expected to
occur; Avangrid did not request and NMFS is not authorizing take by Level A harassment of
North Atlantic right whales. Given that North Atlantic right whales are reported frequently,
Avangrid would be required to monitoring the sighting network for this species, and conduct
acoustic monitoring, it is not expected that a North Atlantic right whale would be missed during

monitoring and therefore, Level A harassment of this species is not requested and NMFS may
not authorize incidental to UXO/MEC detonation.

Table 30 – Maximum Monthly Marine Mammal Densities (Individuals/100 km2) Within the Project Area with UXO/MEC Detonation
Associated Level A Harassment (PTS) and Level B Harassment (TTS SEL) Exposure Assuming 10 dB Attenuation, and Estimated Take
Species

Shallow OECC
Maximum Monthly
Density
(Individual/100 km2)

Deep OECC
Maximum Monthly
Density
(Individual/100 km2)

North Atlantic right
whalea,b

0.116

Fin whalea

2025 Estimated Take

2026 Estimated Take

Level A Harassment

Level B Harassment

Level A Harassment

Level B Harassment

0.707

14

13

0.007

0.425

7

7

Humpback whale

0.04

0.297

5

5

Minke whale

0.129

1.72

28

27

Sei whalea

0.034

0.191

4

3

Sperm whalea

0.002

0.112

1

1

Atlantic spotted
dolphin

0.013

0.448

1

1

Atlantic white-sided
dolphin

0.051

3.278

3

3

Bottlenose dolphin,
offshore

0.158

1.631

2

2

Common dolphin

0.35

24.845

19

19

Long-finned pilot
whale

0.135

1

1

Short-finned pilot
whale

0.1

1

1

Risso’s dolphin

0.01

0.176

1

1

Harbor porpoise

1.772

10.608

217

193

Gray seal

24.506

13.647

146

80

Harbor seal

55.059

30.662

328

179

Harp seal

24.506

13.647

146

80

a – Denotes species listed under the ESA.
b – Due to the extensive mitigation and monitoring measures specific to North Atlantic right whales for UXO/MEC detonations, it is not
reasonable to expect that take by Level A harassment will occur, therefore, Avangrid did not request and NMFS may not authorize, take by
Level A harassment of North Atlantic right whales.

HRG Surveys
Avangrid’s planned HRG survey activity includes the use of impulsive sources (i.e.,
boomers and sparkers) that have the potential to harass marine mammals. The acoustic sources
expected to result in marine mammal harassment, as defined under the MMPA, are provided in
table 3 of the proposed rule (88 FR 37606, June 8, 2023) and remain unchanged in this final rule.
If authorized, takes will be by Level B harassment only in the form of disruption of
behavioral patterns for individual marine mammals resulting from exposure to noise from certain
HRG acoustic sources. Based primarily on the characteristics of the signals produced by the
acoustic sources planned for use, Level A harassment is neither anticipated, even absent
mitigation, nor planned to be authorized. Please see Avangrid’s application for details of a
quantitative exposure analysis (i.e., calculated distances to Level A harassment isopleths and
Level A harassment exposures). Further, there is no evidence to suggest that serious injury or
mortality is a potential outcome of exposure to HRG survey sources, and none is anticipated.
Therefore, the potential for Level A harassment from HRG surveys is not evaluated further in
this document. Avangrid did not request, and NMFS may not authorize, take by Level A
harassment incidental to HRG surveys. No serious injury or mortality is anticipated to result
from HRG survey activities.
Specific to HRG surveys, in order to better consider the narrower and directional beams
of the sources, NMFS has developed a tool for determining the sound pressure level (SPLrms) at
the 160-dB isopleth for the purposes of estimating the extent of Level B harassment isopleths
associated with HRG survey equipment (NMFS, 2020). This methodology incorporates
frequency-dependent absorption and some directionality to refine estimated ensonified zones.
Avangrid used NMFS' methodology with additional modifications to incorporate a seawater
absorption formula and account for energy emitted outside of the primary beam of the source.
For sources that operate with different beamwidths, the maximum beam width was used, and the

lowest frequency of the source was used when calculating the frequency-dependent absorption
coefficient.
The isopleth distances corresponding to the Level B harassment threshold for each type
of HRG equipment with the potential to result in harassment of marine mammals were calculated
per “NOAA Fisheries’ Interim Recommendation for Sound Source Level and Propagation
Analysis for High Resolution Geophysical Sources.” The distances to the 160-dB RMS re 1 μPa
isopleth for Level B harassment are presented in table 31. Please refer to appendix I in Li and
Koessler (2022) of the LOA application for a full description of the methodology and formulas
used to calculate distances to the Level B harassment threshold.
Table 31 – Isopleth Distances in Meters (m) Corresponding to Level B Harassment
Threshold for HRG Equipment
HRG Survey Equipment

Equipment Type

Horizontal Distance (m)
to Level B Harassment
Threshold

Ensonified Area (km2)

Applied Acoustics AA251
Boomer

SBP: Boomer

28.58

GeoMarine Geo Spark
2000 (400 tip)

SBP: Sparker

22.62

The survey activities that have the potential to result in Level B harassment (160 dB SPL)
include the noise produced by Applied Acoustics AA251 Boomer or GeoMarine Geo Spark 2000 (400
tip) (table 31), of which the Applied Acoustics AA251 Boomer results in the greatest calculated
distance to the Level B harassment criteria at 178 m (584 ft). Avangrid has applied the estimated
distance of 178 m (584 ft) to the 160 dBRMS90 percent re 1 μPa Level B harassment criteria as the basis
for determining potential take from all HRG sources. All noise-producing survey equipment is
assumed to be operated concurrently. Three vessels are assumed to be operating concurrently.
The basis for the take estimate is the number of marine mammals that would be exposed
to sound levels in excess of the Level B harassment threshold (160 dB). Typically, this is
determined by estimating an ensonified area for the activity, by calculating the area associated
with the isopleth distance corresponding to the Level B harassment threshold. This area is then
multiplied by marine mammal density estimates in the Project Area and then corrected for

seasonal use by marine mammals, seasonal duration of Project-specific noise-generating
activities, and estimated duration of individual activities when the maximum noise-generating
activities are intermittent or occasional.
The total area ensonified was estimated by considering the distance of the daily vessel track
line (determined using the estimated average speed of the vessel and the 24-hour operational period
within each of the corresponding survey segments) and the longest horizontal distance to the relevant
acoustic threshold from an HRG sound source (full formula in section 6.6 of the ITA application).
Using the larger distance of 178 m (164 ft)) to the 160 dBRMS90 percent re 1 μPa Level B harassment
isopleth (table 31), the estimated daily vessel track of approximately 80 km (49.7 mi) per vessel for
24-hour operations, inclusive of an additional circular area to account for radial distance at the start
and end of a 24-hour cycle, estimates of the total area ensonified to the Level B harassment threshold
per day of HRG surveys were calculated (table 31).
Exposure calculations assumed that there would be 25 days of HRG surveying per year over
each of the 5 years. As described in the ITA application, density data were mapped within the
boundary of the Project Area using geographic information systems, these data were updated based on
the revised data from the Roberts et al. (2022) model. Because the exact dates of HRG surveys are
unknown, the highest density month for each species was used and carried forward in the take
calculations (table 32).
The calculated exposure estimates based on the exposure modeling methodology described
above were compared with the best available information on marine mammal group sizes. Group sizes
used for HRG take estimates were the same as those used for impact pile driving take estimation
(section 6.1.2 in the ITA application). Avangrid also used data collected by PSOs on survey vessels
operating during HRG surveys in 2020–2021 from their nearby Vineyard Wind project area. It was
determined that the calculated number of potential takes by Level B harassment based on the exposure
modeling methodology above may be underestimates for some species and therefore warranted
adjustment using group size to ensure conservatism in the take numbers NMFS may authorize. Despite

the relatively small modeled Level B harassment zone (178 m) for HRG survey activities, it was
determined that adjustments to the requested numbers of take by Level B harassment for some dolphin
species was warranted to be conservative (see below).
For certain species for which the density-based methodology described above may result in
potential underestimates of take and Avangrid’s PSO sightings data were relatively low, adjustments
to the exposure estimates were made based on the best available information on marine mammal group
sizes to ensure conservatism. For species with densities too low in the region to provide meaningful
modeled exposure estimates (i.e., rare species), the take request is based on the average group size
(table 11). For species not considered rare in the Project Area, but AMAPP data or Avangrid PSO data
show a higher group size level than the Roberts et al. (2022) model, then the takes by Level B
harassment requested for authorization were adjusted to one group size per day of HRG surveys (table
32).
For species considered rare but that still have the small potential for occurrence in the Project
area, takes by Level B harassment during HRG surveys were requested by Avangrid. This occurred for
white-beaked dolphin, killer whale, and false killer whale. Avangrid based their takes requested for
authorization on these species by using one group size per year in 3 of 5 years for species. Group sizes
used were based on PSO observations during previous HRG surveys.

Table 32 – Marine Mammal Densities Used in Exposure Estimates and Estimated Takes by Level B Harassment from HRG Surveys
Species

Maximum Monthly
Densitya (No./100 km2)

Annual Exposure Using
the Boomerf

Annual Exposure Using
the Sparkerg

Annual Level B
Harassment Take

5-Year Total Level B
Harassment Take

North Atlantic right whaleb

0.567

4.05

3.21

25

Fin whaleb

0.436

3.11

2.47

20

Humpback whale

0.323

2.31

1.83

15

Minke whale

1.704

12.17

9.64

65

Sei whaleb

0.193

1.38

1.09

10

Sperm whaleb,h

0.111

0.79

0.62

10

Atlantic spotted dolphinh

0.404

2.88

2.28

150

Atlantic white-sided
dolphinh

3.406

24.34

19.26

140

Bottlenose dolphin,
offshoreh

1.753

12.53

9.92

90

Common dolphinc

28.314

202.3

160.13

1,015

Long-finned pilot whaled,h

0.149

1.06

0.84

85

Short-finned pilot whaled,h

0.11

0.78

0.62

45

Risso’s dolphinh

0.187

1.34

1.06

35

False Killer whalei

N/A

N/A

N/A

15

Killer whalei

N/A

N/A

N/A

6

White-beaked dolphini

N/A

N/A

N/A

90

Harbor porpoise

10.974

78.41

62.07

395

Gray seale

27.901

199.35

157.8

1,000

Harbor seale

62.687

447.89

354.54

2,240

Harp seale

27.901

199.35

157.8

1,000

a – Cetacean density values from the Roberts et al. (2016, 2022) model.
b – Listed as Endangered under the ESA.

c – Take rounded up to one group size.
d – Long- and short-finned pilot whale densities are the annual pilot whale guild density scaled by their relative abundances.
e – Gray and harbor seal densities are the seals guild density scaled by their relative abundances; gray seals are used as a surrogate for harp
seals.
f – Applied Acoustics AA251 boomer.
g – GeoMarine Geo Spark 2000.
h – Annual take by Level B harassment is rounded up to one group size.
i – Rare species total take estimates are based on the assumption that a group would be seen every other year; hence, the 5-yr total is less than
the sum of each year.

Total Authorized Take Across All Activities
The amount of Level A harassment and Level B harassment NMFS may be authorizing
incidental to all project activities combined (i.e., pile driving and drilling to install WTG and
ESP monopile and jacket foundations, UXO/MEC detonations, and HRG surveys) are shown in
table 33. The annual amount of take which may be authorized reflects the maximum number of
take that may occur in each year, based on Avangrid’s current schedules, as provided in table 1.
Year 1 (2024) take estimates include HRG surveys and UXO/MEC detonations. Year 2 take
includes all activities occurring: WTG and ESP foundation installation, HRG surveys, and
UXO/MEC detonation. Year 3 includes WTG and ESP foundation installation and HRG surveys.
Year 4 take includes WTG and ESP foundation installation (assuming construction schedule B)
and HRG surveys. Year 5 take includes HRG surveys only. All activities are expected to be
completed by 2030, equating to the 5 years of activities, as described in this preamble. NMFS
recognizes that schedules may shift due to a number of planning and logistical constraints such
that take may be redistributed throughout the 5 years. However, the total 5-year amount of take
for each species, shown in table 33, and the maximum annual take in any one year (table 35)
must not be exceeded. Additionally, to reduce impacts to marine mammals, NMFS has required
several mitigation and monitoring measures, provided in the Mitigation and Monitoring and
Reporting sections, which are activity-specific and are designed to minimize acoustic exposures
to marine mammal species.
For common and uncommon, though not “rare,” species where the exposure estimate was
less than the mean group size, it was assumed that if one group member was exposed, then the
entire group would be exposed. For species where the annual number of predicted exposures was
less than the mean group size, the annual take was increased to the mean group size rounded up
to the nearest integer. The only species this applied to are the sei whale, Atlantic spotted dolphin,
Risso's dolphin, and sperm whale. Because pile driving would occur over either 2 or 3 years, the
mean group size rule was carried over from each of the annual take estimates to the total take

estimates for the entire construction schedule to account for the possibility that a single exposure
could occur in every year of a given construction schedule.
For species that are considered rare but still have the slight potential for occurrence in the
Project area, Avangrid requested an amount of annual take assuming one group size of that
species may be harassed in any given year. However, due to how rare these species are in the
project area, it is not assumed that they would be encountered every year, instead, a group is
anticipated to occur only every other year; hence the total amount of take of the 5 years is less
than the sum of the annual take across all 5 years. As described above, takes for these species are
based on PSO sighting group sizes or on group size from OBIS data. NMFS concurs with this
assessment and may authorize takes by Level A harassment and/or Level B harassment for these
rare species (table 33).
The amount of take that Avangrid requested, and NMFS may authorize is considered
conservative. NMFS does not typically authorize take of rare species in these circumstances;
however, given the amount of foundation installation activities that Avangrid is proposing to
undertake (i.e., installation of up to 129 WTG and 2-5 ESP positions), the large harassment zone
sizes estimated from foundation installation, the duration of the foundation installation (up to 3
years), that marine mammal distribution is changing and that foundation installation is not
scheduled to begin until 2026, NMFS is proposing to allow take for rare species. The one
exception is the request for take of beluga whales. There is no beluga whale stock in the U.S.
Atlantic and the potential for a beluga whale to occur is incredibly unlikely. Hence, NMFS may
not authorize take of beluga whales.
For the species for which modeling was conducted, the allowable take is considered
conservative for a number of reasons. The amount of take that may be authorized assumes the
most impactful scenario with respect to project design and schedules. As described in the
Description of Specific Activities section, Avangrid plans to use monopile and jacket
foundations (inclusive of bottom-frame foundations) for all permanent structures (i.e., WTGs and

ESPs). The take that NMFS may authorize for pile driving assumed a maximum piling schedule
of two monopiles and four pin piles installed per 24-hour period. The take numbers NMFS may
authorize for pile driving are conservatively based on the maximum densities across the
construction months. The take numbers that NMFS may authorize for Level A harassment do not
fully account for the likelihood that marine mammals would avoid a stimulus when possible
before the individual accumulates enough acoustic energy to potentially cause auditory injury,
nor do these numbers account for the effectiveness of the required mitigation measures.
If authorized, takes by Level A harassment and Level B harassment for the combined
activities of pile driving and drilling during the installation of monopiles and pin piles (assuming
10 dB of sound attenuation), UXO/MEC detonation, and HRG surveys are provided in tables 33
and 34. NMFS also presents the percentage of each marine mammal stock estimated to be taken
based on the total amount of annual take in table 35. To inform the negligible impact analysis,
NMFS assesses the greatest amount of take of marine mammals allowable in any given year
(which in the case of this rule is based on the predicted Year 1 for all species), as well as the total
allowable take across all 5 years of the rule. Table 35 also depicts the amount of take relative to
each stock assuming that each individual is taken only once, which specifically informs the small
numbers determination. Table 34 provides the total take that may be authorized from the entire
5-year effective period of the rule and, if issued, associated LOA.
As a result of the updated modeling for impact pile driving, vibratory pile driving, and
drilling, takes by Level A harassment and Level B harassment decreased for many species
(values in bold in table 33, 34, and 35). Rare species, having not been included in the modeling
for the proposed or final rule, as they are based on OBIS or PSO sighting data, are unchanged
since the proposed rule with the exception of the Northern bottlenose whale. Northern bottlenose
whale takes by Level B harassment decreased from 12 to 8 as a result of a correction submitted
in the January 2024 Application Update by Avangrid (as previously described in the Changes in
Information Provided in the Preamble).

Table 33 – Level A Harassment and Level B Harassment Takes for All Activities That May Be Authorized During the Construction and
Development of the Project Over 5 Years
Year 1

Year 2

Year 3

Year 4

Year 5

Total 5-Y Take

Level A
Harassme
nt

Level B
Harassme
nt

Level A
Harassme
nt

Level B
Harassme
nt

Level A
Harassme
nt

Level B
Harassme
nt

Level A
Harassme
nt

Level B
Harassme
nt

Level A
Harassme
nt

Level B
Harassme
nt

Level A
Harassme
nt

Level B
Harassme
nt

Total
Takes by
Harassme
nte

North
Atlantic
right
whale

19

39

46

23

5

126

Blue
whale

0

2

2

2

0

4

Fin whale

11

122

194

72

4

386

Humpbac
k whale

8

84

129

58

3

270

Minke
whale

41

305

480

219

13

1046

Sei whale

6

17

27

15

2

66

Sperm
whale

3

32

56

20

2

108

Dwarf
sperm
whale

0

2

2

2

0

4

Pygmy
sperm
whale

0

2

2

2

0

4

Cuvier's
beaked
whale

0

3

3

3

0

6

Blainville'
s beaked
whale

0

4

4

4

0

8

Species

Gervais'
beaked
whale

0

4

4

4

0

8

Sowerby's
beaked
whale

0

4

4

4

0

8

True's
beaked
whale

0

3

3

3

0

6

Northern
bottlenose
whaled

0

4

4

4

0

8

Atlantic
spotted
dolphin

31

116

169

73

30

380

Atlantic
white
sided
dolphin

31

905

1713

788

28

3329

Bottlenos
e dolphin,
offshore

20

872

2065

772

18

3541

Clymene
dolphin

0

167

167

167

0

334

Common
dolphin

222

12501

26553

10023

203

46759

Longfinned
pilot
whale

18

118

216

92

17

440

Shortfinned
pilot
whale

10

21

20

19

9

78

Risso’s
dolphin

8

172

456

147

7

720

False
killer
whale

5

7

12

7

5

25

Fraser’s
dolphin

0

192

192

192

0

384

Killer
whale

2

8

10

8

2

10

Melonheaded
whale

0

109

109

109

0

218

Pantropic
al Spotted
dolphin

0

60

60

60

0

120

Pygmy
killer
whale

0

5

5

5

0

10

Roughtoothed
dolphin

0

14

14

14

0

28

Spinner
dolphin

0

51

51

51

0

102

Striped
dolphin

0

64

64

64

0

128

Whitebeaked
dolphin

30

14

44

14

30

150

Harbor
porpoise

296

755

902

394

79

2343

Gray seal

346

887

1391

762

200

3290

Harbor
seal

776

980

973

718

448

3832

Harp seal

346

1000

1867

982

200

4062

Hooded
seal

0

1

1

1

0

2

Note: The annual takes are the maximum between the two construction schedules (A or B); therefore, year 2 is the maximum annual takes
under Schedule A while years 3 and 4 are the maximum annual takes under Schedule B. As the total 5-Y takes for Schedule B are more than
Schedule A, the total takes that may be authorized is based on Schedule B. Therefore, the sum of the annual takes that may be authorized do
not add up to the total 5-Y takes which may be authorized. Values in bold for the 5-Y takes are less than in the proposed rule.
a – The final rule and LOA, if issued, would be effective from March 27, 2025 to March 26, 2030
b – For days when pile installation includes both vibratory setting and drilling, only the vibratory setting Level B harassment takes are included
(because more takes are predicted for this activity) and not the drilling Level B takes to avoid double counting. For the purpose of this take
request, year 1 is assumed to be 2025. These dates reflect the currently projected construction start year and are subject to change because exact
project start dates and construction schedules are not currently available.
c – Rare species in the project area. Rare species total take estimates for the project are based on the assumption that a group would be seen
every other year; hence, the 5-Y total is less than the sum of all years combined.
d – Northern bottlenose whale takes by Level B harassment has been decreased from 12 to 8 as a result of a typo correction submitted in the
January 2024 Application Update by Avangrid. Avangrid had previously not adjusted the total take request for this rare species by assuming
encounters every other year but instead had unintentionally summed all annual takes at the time of the proposed rule.
e – The amount of total takes for 5-Y, is the sum of the 5-Y takes by Level A harassment and takes by Level B harassment.

In making the negligible impact determination and the necessary small numbers finding,
NMFS assesses the maximum total number of takes (Level A harassment and Level B
harassment) of marine mammals species or stocks allowable within any one year, and in the
negligible impact determination we also assess the impacts of the total take allowable over the 5year period. In this calculation, the maximum estimated number of Level A harassment takes in
any one year is summed with the maximum estimated number of Level B harassment takes in
any one year for each species to yield the highest number of estimated take that could occur in
any year (table 35). We recognize that certain activities could shift within the 5-year effective
period of the rule and the rule allows for that flexibility, however, the takes are not allowed to
exceed the maximum annual take shown in table 35 in any year. Of note, the maximum amount
of take by Level A harassment is higher for some species in year 1 due to UXO/MEC
detonations, though year 3 has the maximum amount of take when takes by Level A harassment
is combined with those from Level B harassment. As schedules may shift, and to not
underestimate the amount of takes by harassment, the takes under UXO/MEC detonation have
been moved to Year 3 (table 34). Year 3 is the year with the maximum amount of take for
foundation installation and maximum amount of take when Level A harassment and Level B
harassment are combined (table 34).

Table 34 – Maximum Number of Takes by Harassment that may be Authorized Under Year 1 UXO/MEC Detonation Added to the
Maximum Number of Takes that may be Authorized for Year 3 to Create the Maximum Annual Takes
Species

UXO/MEC Maximum
Year 1 Level A
Harassment

UXO/MEC Maximum
Year 1 Level B
Harassment

Year 3 Maximum
Level A Harassment

Year 3 Maximum
Level B Harassment

Total Maximum
Annual Level A
Harassmenta

Total Maximum
Annual Level B
Harassmenta

North Atlantic right
whalec

14

46

60

Blue whalec,d

0

2

2

Fin whalec

7

194

201

Humpback whale

5

129

134

Minke whale

28

480

508

Sei whalec

4

27

31

Sperm whalec

1

56

57

Dwarf sperm whaled

0

2

2

Pygmy sperm whaled

0

2

2

Cuvier's beaked whaled

0

3

3

Blainville's beaked
whaled

0

4

4

Gervais' beaked whaled

0

4

4

Sowerby's beaked
whaled

0

4

4

True's beaked whaled

0

3

3

Northern bottlenose
whaled

0

4

4

Atlantic spotted
dolphind

1

169

170

Atlantic white-sided
dolphin

3

1713

1716

Bottlenose dolphin,
offshore

2

2065

2067

Clymene dolphind

0

167

167

Common dolphin

19

26553

26572

Long-finned pilot whale

1

216

217

Short-finned pilot whale

1

20

21

Risso’s dolphin

1

456

457

False killer whale

0

12

12

Fraser’s dolphind

0

192

192

Killer whaled

0

10

10

Melon-headed whaled

0

109

109

Pantropical Spotted
dolphind

0

60

60

Pygmy killer whaled

0

5

5

Rough-toothed dolphind

0

14

14

Spinner dolphind

0

51

51

Striped dolphind

0

64

64

White-beaked dolphind

0

44

44

Harbor porpoise

217

902

1119

Gray seal

146

1391

1537

Harbor seal

328

973

1301

Harp seal

146

1867

2013

Hooded seald
0
0
0
1
0
a – The maximum values is the sum of the Year 1 takes by harassment for UXO/MECs and the takes by harassment for all year 3 activities
(foundation installation and HRG). Values in bold are the result of the addition of UXO/MEC takes to year 3 takes.
b – Using the draft 2023 stock assessment report (SAR) at time of publication as it is represents the best available science (89 FR 5495, January
29, 2024).
c – Listed as Endangered under the ESA.
d – Rare species in the project area. The number of Level A harassment and Level B harassment takes calculated for rare species is based on
the mean group size assuming a 3 year construction schedule (all rare species) and encounters during HRG surveys for white-beaked dolphin,
killer whale, and false killer whale.

Table 35 – Maximum Number of Takes (Level A Harassment and Level B Harassment) that may be Authorized in Any One Year of the
Project and the Percent of Stock that Would be Taken Based on the Maximum Annual Take that may be Authorized
Species

NMFS Stock Abundanceb

Maximum Annual Level A
Harassment

Maximum Annual Level B
Harassment

Maximum Annual Take

Percent Of Stock Taken
Based on Maximum
Annual Takea

North Atlantic right whalec

0

60

17.65

1

3

0.75

Fin whalec

21

222

3.26

Humpback whale

18

152

10.89

Minke whale

90

598

2.72

4

35

0.56

1

58

0.98

Blue

Sei

whalec,d

whalec

Sperm

whalec

Dwarf sperm whaled

2

4

0.04

whaled

2

4

0.04

0

3

0.06

0

4

0.14

0

4

0.05

0

4

0.81

0

3

0.07

UNK

4

UNK

1

171

0.54

Atlantic white-sided dolphin

1

1717

1.84

Bottlenose dolphin, offshore

Pygmy sperm

Cuvier's beaked whaled
Blainville's beaked
Gervais' beaked

whaled

whaled

Sowerby's beaked whaled
True's beaked

whaled

Northern bottlenose whaled
Atlantic spotted

dolphind

1

2068

3.20

dolphind

0

167

0.77

Common dolphin

1

26573

28.54

Long-finned pilot whale

1

218

0.56

Short-finned pilot whale

1

22

0.12

Risso’s dolphin

1

458

1.04

False killer whale

0

12

0.92

dolphind

UNK

192

UNK

whaled

UNK

10

UNK

UNK

109

UNK

0

60

2.18

UNK

5

UNK

UNK

14

UNK

Spinner dolphind

0

51

1.60

dolphind

0

64

0.13

0

44

0.01

Harbor porpoise

67

1186

1.38

Gray seal

9

1546

5.54

Harbor seal

18

1319

2.15

Harp seal

9

2022

0.03

Clymene

Fraser’s
Killer

Melon-headed whaled
Pantropical Spotted

dolphind

Pygmy killer whaled
Rough-toothed
Striped

White-beaked

dolphind

dolphind

Hooded seald

UNK

0
1
1
Note: Year 3 of the project is expected to have the greatest amount of Level B harassment take possible. However, the years where UXO/MEC
detonation could occur (currently scheduled for only years 1 and 2) have a higher amount of take by Level A harassment for some species; as
the UXO/MEC detonation may shift, the Year 1 UXO/MEC takes were added to the foundation installation and HRG year 3 takes. Values in
bold are a result of UXO/MEC takes by harassment being added to the Year 3 take amounts.
a – The values in this column represent the assumption that each take that may be authorized would occur to a unique individual. Given the
scope of work proposed, this is highly unlikely for species common to the project area (e.g., North Atlantic right whales, humpback whales)
such that the actual percentage of the population taken is less than the percentages identified here.
b – Using the draft 2023 stock assessment report (SAR) at time of publication as it is represents the best available science (89 FR 5495, January
29, 2024).
c – Listed as Endangered under the ESA.
d – Rare species in the project area. The number of Level A harassment and Level B harassment takes calculated for rare species is based on
the mean group size assuming a 3-year construction schedule (all rare species) and encounters during HRG surveys for white-beaked dolphin,
killer whale, and false killer whale.

UNK

Mitigation
As noted in the Changes from the Proposed to Final Rule section, NMFS has added
several new mitigation requirements and clarified a few others and has changed the minimum
visibility zone for mysticetes and shutdown zone for North Atlantic right whales. These changes
are described in detail in the sections below. Besides these changes, the required measures
remain the same as those described in the proposed rule. However, NMFS has also re-organized
and simplified the section to avoid full duplication of the specific requirements that are fully
described in the regulatory text.
In order to promulgate a rulemaking under section 101(a)(5)(A) of the MMPA, NMFS
must set forth the permissible methods of taking pursuant to the activity, and other means of
effecting the least practicable adverse impact on the species or stock and its habitat, paying
particular attention to rookeries, mating grounds, and areas of similar significance, and on the
availability of the species or stock for taking for certain subsistence uses (latter not applicable for
this action). NMFS’ regulations require applicants for ITAs to include information about the
availability and feasibility (e.g., economic and technological) of equipment, methods, and
manner of conducting the activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks and their habitat (50 CFR 216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to ensure the least
practicable adverse impact on species or stocks and their habitat, as well as subsistence uses
where applicable, we carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful implementation of the
measure(s) is expected to reduce impacts to marine mammals, marine mammal species or stocks,
and their habitat. This considers the nature of the potential adverse impact being mitigated (e.g.,
likelihood, scope, range). It further considers the likelihood that the measure will be effective if
implemented (i.e., the probability of accomplishing the mitigating result if implemented as

planned), the likelihood of effective implementation (i.e., the probability if implemented as
planned); and
(2) The practicability of the measures for applicant implementation, which may consider
factors such as cost, impact on operations, personnel safety, and practicality of implementation,
and, in the case of a military readiness activity, impact on the effectiveness of the military
readiness activity.
The mitigation strategies described below are consistent with those required and
successfully implemented under previous ITAs issued in association with in-water construction
activities (e.g., soft-start, establishing shutdown zones). Additional measures have also been
incorporated to account for the fact that the construction activities would occur offshore.
Modeling was performed to estimate harassment zones, which were used to inform mitigation
measures for the Project’s activities to minimize Level A harassment and Level B harassment to
the extent practicable, while providing estimates of the areas within which Level B harassment
might occur.
Generally speaking, the mitigation measures considered and required here fall into three
categories: temporal (i.e., seasonal and daily) and spatial work restrictions, real-time measures
(e.g., shutdown, clearance, and vessel strike avoidance), and noise attenuation/reduction
measures. Temporal and spatial work restrictions are designed to avoid or minimize operations
when marine mammals are concentrated or engaged in behaviors that make them more
susceptible or make impacts more likely, in order to reduce both the number and severity of
potential takes, and are effective in reducing both chronic (longer-term) and acute effects. Realtime measures, such as implementation of shutdown and clearance zones, as well as vessel strike
avoidance measures, are intended to reduce the probability or severity of harassment by taking
steps in real time once a higher-risk scenario is identified (e.g., once animals are detected within
an impact zone). Noise attenuation measures such as bubble curtains are intended to reduce the

noise at the source, which reduces both acute impacts, as well as the contribution to aggregate
and cumulative noise that may result in longer term chronic impacts.
Below, we briefly describe the required training, coordination, and vessel strike
avoidance measures that apply to all activity types, and in the following subsections we describe
the measures that apply specifically to foundation installation, UXO/MEC detonations, and HRG
surveys. Details on specific requirements can be found in 50 CFR part 217, subpart GG, set out
at the end of this rule.
Training and Coordination
NMFS requires all Avangrid employees and contractors conducting activities on the
water, including but not limited to, all vessel captains and crew to be trained in marine mammal
detection and identification, communication protocols, and all required measures to minimize
impacts on marine mammals and support Avangrid’s compliance with the LOA, if issued.
Additionally, all relevant personnel and the marine mammal species monitoring team(s) are
required to participate in joint, onboard briefings prior to the beginning of project activities. The
briefing must be repeated whenever new relevant personnel (e.g., new PSOs, construction
contractors, relevant crew) join the Project before work commences. During this training,
Avangrid is required to instruct all project personnel regarding the authority of the marine
mammal monitoring team(s). For example, the HRG acoustic equipment operator, pile driving
personnel, etc., is required to immediately comply with any call for a delay or shutdown by the
Lead PSO. Any disagreement between the Lead PSO and the Project personnel must only be
discussed after delay or shutdown has occurred. In particular, all captains and vessel crew must
be trained in marine mammal detection and vessel strike avoidance measures to ensure marine
mammals are not struck by any project or project-related vessel.
Prior to the start of in-water construction activities, vessel operators and crews will
receive training about marine mammals and other protected species known or with the potential
to occur in the Project Area, making observations in all weather conditions, and vessel strike

avoidance measures. In addition, training will include information and resources available
regarding applicable Federal laws and regulations for protected species. Avangrid will provide
documentation of training to NMFS. Since the proposed rule, NMFS has added requirements for
a description of the training program to be provided to NMFS at least 60 days prior to the initial
training before in-water activities begin and for confirmation of all required training to be
documented on a training course log sheet and reported to NMFS Office of Protected Resources
prior to initiating project activities. These measures were added in response to several
commenters’ concerns regarding strengthening mitigation and monitoring measures.
North Atlantic Right Whale Awareness Monitoring
Avangrid must use available sources of information on North Atlantic right whale
presence, including daily monitoring of the Right Whale Sightings Advisory System, monitoring
of Coast Guard VHF Channel 16 throughout each day to receive notifications of any sightings,
and information associated with any regulatory management actions (e.g., establishment of a
zone identifying the need to reduce vessel speeds). Maintaining daily awareness and
coordination affords increased protection of North Atlantic right whales by understanding North
Atlantic right whale presence in the area through ongoing visual and PAM efforts and
opportunities (outside of Avangrid’s efforts), and allows for planning of construction activities,
when practicable, to minimize potential impacts on North Atlantic right whales. The vessel strike
avoidance measures apply to all vessels associated with the Project within U.S. waters and on the
high seas.
Vessel Strike Avoidance Measures
This final rule contains numerous vessel strike avoidance measures that reduce the risk
that a vessel and marine mammal could collide. While the likelihood of a vessel strike is
generally low, vessel strikes are one of the most common ways that marine mammals are
seriously injured or killed by human activities. Therefore, enhanced mitigation and monitoring
measures are required to further avoid vessel strikes to the extent practicable. While many of

these measures are proactive, intended to avoid the heavy use of vessels during times when
marine mammals of particular concern may be in the area, several are reactive and occur when a
marine mammal is sighted by project personnel. The mitigation requirements are described
generally here and in detail in the regulatory text at the end of this final rule (50 CFR
217.324(b)). Avangrid will be required to comply with these measures, except under
circumstances when doing so would create an imminent and serious threat to a person or vessel,
or to the extent that a vessel is unable to maneuver and, because of the inability to maneuver, the
vessel cannot comply.
While underway, Avangrid is required to monitor for and maintain a safe distance from
marine mammals, and operate vessels in a manner that reduces the potential for vessel strike.
Regardless of the vessel’s size, all vessel operators, crews, and dedicated visual observers (i.e.,
PSO or trained crew member) must maintain a vigilant watch for all marine mammals and slow
down, stop their vessel, or alter course as appropriate to avoid striking any marine mammal. The
dedicated visual observer, equipped with suitable monitoring technology (e.g., binoculars, night
vision devices), must be located at an appropriate vantage point for ensuring vessels are
maintaining required vessel separation distances from marine mammals (e.g., 500 m from North
Atlantic right whales).
All project vessels, regardless of size, must maintain the following minimum separation
zones: 500 m from North Atlantic right whales; 100 m from sperm whales and non-North
Atlantic right whale baleen whales; and 50 m from all delphinid cetaceans and pinnipeds (an
exception is made for those species that approach the vessel (i.e., bow-riding dolphins)). If any
of these species are sighted within their respective minimum separation zone, the underway
vessel must shift its engine to neutral and the engines must not be engaged until the animal(s)
have been observed to be outside of the vessel’s path and beyond the respective minimum
separation zone. If a North Atlantic right whale is observed at any distance by any project
personnel or acoustically detected, project vessels must reduce speeds to 10 knots (kn).

Additionally, in the event that any project-related vessel, regardless of size, observes any large
whale (other than a North Atlantic right whale) within 500 m of an underway vessel, the vessel is
required to shift engines into neutral. The vessel shall remain in neutral until the North Atlantic
right whale has moved beyond 500 m and the 10 kn speed restriction will remain in effect as
outlined in 50 CFR 217.314(b). When NMFS vessel speed restrictions are not in effect and a
vessel is traveling at greater than 10 kn, in addition to the required dedicated visual observer,
Avangrid is required to monitor the transit corridor in real-time with PAM prior to and during
transits. To maintain awareness of North Atlantic right whale presence in the Project Area, vessel
operators, crew members, and the marine mammal monitoring team will monitor U.S. Coast
Guard VHF Channel 16, WhaleAlert, the Right Whale Sighting Advisory System (RWSAS), and
the PAM system. Any North Atlantic right whale or large whale detection will be immediately
communicated to PSOs, PAM operators, and all vessel captains.
All vessels will be equipped with an AIS and Avangrid must report all MMSI numbers to
NMFS Office of Protected Resources prior to initiating in-water activities. The requirement for
vessels to be equipped with AIS has been added since the proposed rule to increase the
accountability of project vessels. Avangrid will submit a NMFS-approved Marine Mammal
Vessel Strike Avoidance Plan at least 180 days prior to commencement of vessel use.
Compliance with these measures will reduce the likelihood of vessel strike to the extent
practicable. These measures increase awareness of marine mammals in the vicinity of project
vessels and require project vessels to reduce speed when marine mammals are detected (by
PSOs, PAM, and/or through another source, e.g., RWSAS) and maintain separation distances
when marine mammals are encountered. While visual monitoring is useful, reducing vessel
speed is one of the most effective, feasible options available to reduce the likelihood of, and
effects from, a vessel strike. Numerous studies have indicated that slowing the speed of vessels
reduces the risk of lethal vessel collisions, particularly in areas where right whales are abundant

and vessel traffic is common and otherwise traveling at high speeds (Vanderlaan and Taggart,
2007; Conn and Silber, 2013; Van der Hoop et al., 2014; Martin et al., 2015; Crum et al., 2019).
Given the inherent low probability of vessel strike, combined with the vessel strike
avoidance measures included herein, NMFS considers the potential for vessel strike to be
unlikely and would not allow take from this activity under this final rule.
Seasonal and Daily Restrictions
Temporal and spatial restrictions in places where marine mammals are concentrated,
engaged in biologically important behaviors, and/or present in sensitive life stages are effective
measures for reducing the magnitude and severity of human impacts. The temporal restrictions
required here are built around the protection of North Atlantic right whales. Based upon the best
scientific information available (Roberts et al., 2023), the highest densities of North Atlantic
right whales in the Project Area are expected during the months of January through April, with
an increase in density starting in December and continuing through May. However, North
Atlantic right whales may be present in the Project Area throughout the year.
NMFS is requiring seasonal work restrictions to minimize noise exposure to North
Atlantic right whales incidental to certain specified activities to the extent practicable. These
seasonal work restrictions are expected to greatly reduce the number of takes of North Atlantic
right whales that otherwise may have occurred without seasonal restrictions. These seasonal
restrictions also afford protection to other marine mammals that are known to use the Project
Area with greater frequency during winter months, including other baleen whales.
As described previously, no impact pile driving or drilling activities may occur January 1
through April 30 (and December 1 through May 31 for vibratory pile driving). As described in
the proposed rule and carried forward in this final rule, Avangrid is to install the foundations as
quickly as possible and avoid impact pile driving and drilling in December to the maximum
extent practicable; however, impact pile driving and drilling may occur in December if it is
unavoidable and only upon approval from NMFS. Avangrid did not propose to conduct vibratory

pile driving in May or December and doing so is not considered in the take estimates. As such,
this final rule establishes a seasonal restriction of no vibratory pile driving from December 1
through May 31.
No more than two foundation monopiles or four pin piles for jacket foundations (or
bottom-frame foundations) would be installed per day. Monopiles must be no larger than 13 m in
diameter and pin piles must be no larger than 4 m in diameter. For all monopiles and pin piles,
the minimum amount of hammer energy necessary to effectively and safely install and maintain
the integrity of the piles must be used. Hammer energies must not exceed 6,000 kJ for monopile
installation or 3,500 kJ for pin pile installation. No more than one pile may be installed at a given
time (i.e., concurrent/simultaneous pile driving and drilling may not occur).
Pile driving and drilling (i.e., foundation installation) must not be initiated earlier than 1
hour after civil sunrise or later than 1.5 hours prior to civil sunset. Generally, foundation
installation may continue after dark when the installation of the same pile began during daylight
(1.5 hours before civil sunset), when clearance zones were fully visible for at least 30 minutes
and must proceed for human safety or installation feasibility reasons. The exception to these
limitations would be if Avangrid submits, and NMFS approves, an Alternative Monitoring Plan
as part of the Foundation Installation and Marine Mammal Monitoring Plan (i.e., Nighttime
Monitoring Plan) that reliably demonstrates the efficacy of detecting marine mammals at night
with its proposed devices. Nighttime hours are defined as the hours between 1.5 hours prior to
civil sunset until 1 hour after civil sunrise. Foundation installation will not be initiated when the
minimum visibility zones cannot be fully visually monitored, as determined by the lead PSO on
duty.
As with foundation installation, NMFS is similarly restricting UXO/MEC detonations
December through May, annually; however, Avangrid may detonate a UXO/MEC in December
or May with NMFS' advanced approval on a case-by-case basis. NMFS is requiring this seasonal
work restriction to minimize the North Atlantic right whales risk of exposure to noise incidental

to foundation installation and UXO/MEC detonation. These seasonal work restrictions are
expected to greatly reduce the number of takes of North Atlantic right whales that would have
otherwise occurred should all activities be conducted during these months. These seasonal
restrictions also afford protection to other marine mammals that are known to use the project
area with greater frequency during winter months, including other baleen whales. No more than
one UXO/MEC may be detonated per 24-hour period. Moreover, detonations may only occur
during daylight hours.
Given the very small harassment zones resulting from HRG surveys and that the best
available science indicates that any harassment from HRG surveys, should a marine mammal be
exposed, would manifest as minor behavioral harassment only (e.g., potentially some avoidance
of the vessel). NMFS is not requiring any seasonal and daily restrictions for HRG surveys.
More information on activity-specific seasonal and daily restrictions can be found in the
regulatory text at the end of this rule.
Noise Abatement Systems
Avangrid is required to employ noise abatement systems (NASs) during all foundation
installation (i.e., impact pile driving, vibratory pile driving, and drilling) activities and
UXO/MEC detonations to reduce the sound pressure levels that are transmitted through the water
to reduce ranges to acoustic thresholds and minimize any acoustic impacts resulting from these
activities. Avangrid is required to use at least two NASs to ensure that measured sound levels do
not exceed the levels modeled for a 10-dB sound level reduction for foundation installation,
which is likely to include a double big bubble curtain or a double big bubble curtain combined
with other NAS (e.g., hydro-sound damper, or an AdBm Helmholz resonator), as well as the
adjustment of operational protocols to minimize noise levels. As part of adaptive management,
should the research and development phase of newer systems demonstrate effectiveness,
Avangrid may submit data on the effectiveness of these systems and request approval from
NMFS to use them during foundation installation and UXO/MEC detonation activities.

Two categories of NASs exist: primary and secondary. A primary NAS would be used to
reduce the level of noise produced by foundation installation activities at the source, typically
through adjustments on to the equipment (e.g., hammer strike parameters). Primary NASs are
still evolving and will be considered for use during mitigation efforts when the NAS has been
demonstrated as effective in commercial projects. However, as primary NASs are not fully
effective at eliminating noise, a secondary NAS would be employed. The secondary NAS is a
device or group of devices that would reduce noise as it was transmitted through the water away
from the pile, typically through a physical barrier that would reflect or absorb sound waves and
therefore, reduce the distance the higher energy sound propagates through the water column.
Together, these systems must reduce noise levels to those not exceeding modeled ranges to Level
A harassment and Level B harassment isopleths corresponding to those modeled assuming 10-dB
sound attenuation, pending results of SFV (see the Sound Field Verification section below and
50 CFR part 217).
Noise abatement systems, such as bubble curtains, are used to decrease the sound levels
radiated from a source. Bubbles create a local impedance change that acts as a barrier to sound
transmission. The size of the bubbles determines their effective frequency band, with larger
bubbles needed for lower frequencies. There are a variety of bubble curtain systems, confined or
unconfined bubbles, and some with encapsulated bubbles or panels. Attenuation levels also vary
by type of system, frequency band, and location. Small bubble curtains have been measured to
reduce sound levels but effective attenuation is highly dependent on depth of water, current, and
configuration and operation of the curtain (Austin et al., 2016; Koschinski and Lüdemann,
2013). Bubble curtains vary in terms of the sizes of the bubbles and those with larger bubbles
tend to perform a bit better and more reliably, particularly when deployed with two separate
rings (Bellmann, 2014; Koschinski and Lüdemann, 2013; Nehls et al., 2016). Encapsulated
bubble systems (e.g., Hydro Sound Dampers (HSDs)), can be effective within their targeted
frequency ranges (e.g., 100–800 Hz), and when used in conjunction with a bubble curtain appear

to create the greatest attenuation. The literature presents a wide array of observed attenuation
results for bubble curtains. The variability in attenuation levels is the result of variation in design
as well as differences in site conditions and difficulty in properly installing and operating inwater attenuation devices. Dähne et al. (2017) found that single bubble curtains that reduce
sound levels by 7 to 10 dB reduced the overall sound level by approximately 12 dB when
combined as a double bubble curtain for 6-m steel monopiles in the North Sea. During
installation of monopiles (consisting of approximately 8 m in diameter) for more than 150 WTGs
in comparable water depths (> 25 m) and conditions in Europe indicate that attenuation of 10 dB
is readily achieved (Bellmann, 2019; Bellmann et al., 2020) using single BBCs for noise
attenuation.
When a double big bubble curtain is used (noting a single bubble curtain is not allowed),
Avangrid is required to maintain numerous operational performance standards. These standards
are defined in the regulatory text at the end of this rule, and include, but are not limited to,
construction contractors must train personnel in the proper balancing of airflow to the bubble
ring and Avangrid must submit a performance test and maintenance report to NMFS within 72
hours following the performance test. Corrections to the attenuation device to meet regulatory
requirements must occur prior to use during foundation installation activities. In addition, a full
maintenance check (e.g., manually clearing holes) must occur prior to each pile being installed.
If Avangrid uses a noise mitigation device in addition to a double big bubble curtain, similar
quality control measures are required. Should the research and development phase of newer
systems demonstrate effectiveness, as part of adaptive management, Avangrid may submit data
on the effectiveness of these systems and request approval from NMFS to use them during
foundation installation activities.
Avangrid is required to submit an SFV plan to NMFS for approval at least 180 days prior
to installing foundations. They are also required to submit interim and final SFV data results to
NMFS and make corrections to the NASs in the case that any SFV measurements demonstrate

noise levels are above those modeled assuming 10 dB. These frequent and immediate reports
allow NMFS to better understand the sound fields to which marine mammals are being exposed
and require immediate corrective action should they be misaligned with anticipated noise levels
within our analysis.
Noise abatement devices are not required during HRG surveys. Regarding HRG surveys,
NAS cannot practicably be employed around a moving survey ship, but Avangrid is required to
make efforts to minimize source levels by using the lowest energy settings on equipment that has
the potential to result in harassment of marine mammals (e.g., boomers) and turning off
equipment when not actively surveying. Overall, minimizing the amount and duration of noise in
the ocean from any of the Project’s activities through use of all means necessary (e.g., noise
abatement, turning off power) will effect the least practicable adverse impact on marine
mammals.
Clearance and Shutdown Zones
NMFS requires the establishment of both clearance and, where technically feasible,
shutdown zones during project activities that have the potential to result in harassment of marine
mammals. The purpose of “clearance” of a particular zone is to minimize potential instances of
auditory injury and more severe behavioral disturbances by delaying the commencement of an
activity if marine mammals are near the activity. The purpose of a shutdown is to prevent a
specific acute impact, such as auditory injury or severe behavioral disturbance of sensitive
species, by halting the activity.
All relevant clearance and shutdown zones during project activities would be monitored
by NMFS-approved PSOs and PAM operators as described in the regulatory text at the end of
this rule. At least one PAM operator must review data from at least 24 hours prior to foundation
installation and UXO/MEC detonations and must actively monitor hydrophones for 60 minutes
prior to commencement of these activities. Any North Atlantic right whale sighting at any
distance by foundation installation PSOs, or acoustically detected within the PAM monitoring

zone (12 km), triggers a delay to commencing pile driving and shutdown. Any large whale
sighted by a PSO or acoustically detected by a PAM operator that cannot be identified as a nonNorth Atlantic right whale must be treated as if it were a North Atlantic right whale.
Prior to the start of certain specified activities (i.e., foundation installation, UXO/MEC
detonation, and HRG surveys), Avangrid must ensure designated areas (i.e., clearance zones as
provided in tables 36 and 37) are clear of marine mammals prior to commencing activities to
minimize the potential for and degree of harassment. For foundation installation and UXO/MEC
detonations, PSOs must visually monitor clearance zones for marine mammals for a minimum of
60 minutes prior to the activity. During this period, the clearance zones will be monitored by
both PSOs and a PAM operator. Prior to the starting these activities, Avangrid will ensure the
area is clear of marine mammals, per the clearance zones in tables 36 and 37, to minimize the
potential for, and the degree of, harassment. All clearance zones must be confirmed to be free of
marine mammals for 30 minutes immediately prior to starting a pile driving (including softstart), drilling, or UXO/MEC detonation. If a marine mammal is observed within a clearance
zone during the pre-start clearance period, the activity will be delayed and may not begin until
the animal(s) has been observed exiting its respective zone, or until an additional time period has
elapsed with no further sightings (i.e., 15 minutes for small odontocetes and pinnipeds and 30
minutes for all other species). In addition, foundation installation and UXO/MEC detonation will
be delayed upon a confirmed PAM detection of a North Atlantic right whale if the PAM
detection is confirmed to have been located within the North Atlantic right whale PAM
Clearance zone. PSO and PAM must continue throughout the duration of foundation installation
and UXO/MEC detonation and for 30 minutes post-completion of the activity. In the event that a
large whale is sighted or acoustically detected that cannot be confirmed as a non-North Atlantic
right whale, it must be treated as if it were a North Atlantic right whale. Because UXO/MEC
detonations are instantaneous, no shutdown is possible; therefore, there are clearance zones but
no shutdown zones for UXO/MEC detonations (table 37).

Clearance and shutdown zones have been developed in consideration of modeled
distances to relevant PTS thresholds with respect to minimizing the potential for take by Level A
harassment. The clearance and shutdown zones for North Atlantic right whales during monopile
and jacket foundation installation are visual observations at any distance by PSOs or any acoustic
detection within the PAM monitoring zone (12 km). The visual and acoustic clearance zones for
large whales other than North Atlantic right whales are 3,300 m (monopile) and 4,900 m (jacket),
which corresponds to the largest modeled exposure range (ER95%) distances to Level A
harassment thresholds (SEL and peak) under all scenarios for all whales, plus 20 percent, then
rounded up for PSO clarity (table 36). The visual and acoustic shutdown zones for large whales
other than North Atlantic right whales are 2,700 m (monopile) and 4,100 m (jacket) for all other
large whales. These distances are also larger than the largest Level A harassment modeled
exposure range (ER95%) for impact pile driving and impact+vibratory pile driving. The clearance
and shutdown zones for other species, which are expected to reduce the likelihood and amount of
Level A harassment and the severity of Level B harassment, are shown in table 36 and will effect
the least practicable adverse impact (LPAI). For North Atlantic right whales, there is an
additional requirement that the clearance zone may only be declared clear if no confirmed North
Atlantic right whale acoustic detections (in addition to visual) have occurred during the 60minute monitoring period.
Once an activity begins, any marine mammal entering their respective shutdown zone
would trigger the activity to cease. In the case of foundation installation, the shutdown
requirement may be waived if it is not practicable to shutdown the equipment due to imminent
risk of injury or loss of life to an individual, risk of damage to a vessel that creates risk of injury
or loss of life for individuals, or where the lead engineer determines there is pile refusal or pile
instability. In situations when shutdown is called for during impact pile driving, but Avangrid
determines shutdown is not practicable due to aforementioned emergency reasons, reduced
hammer energy must be implemented when the lead engineer determines it is practicable.

Specifically, pile refusal or pile instability could result in not being able to shut down pile
driving immediately. Pile refusal occurs when the pile driving sensors indicate the pile is
approaching refusal and a shut-down would lead to a stuck pile which then poses an imminent
risk of injury or loss of life to an individual, or risk of damage to a vessel that creates risk for
individuals. Pile instability occurs when the pile is unstable and unable to stay standing if the
piling vessel were to “let go”. During these periods of instability, the lead engineer may
determine a shut-down is not feasible because the shut-down combined with impending weather
conditions may require the piling vessel to “let go”, which then poses an imminent risk of injury
or loss of life to an individual, or risk of damage to a vessel that creates risk for individuals.
Avangrid must document and report to NMFS all cases where the emergency exemption is taken.
After shutdown, foundation installation may be reinitiated once all clearance zones are
clear of marine mammals for the minimum species-specific periods, or, if required to maintain
pile stability, at which time the lowest hammer energy must be used to maintain stability. If
foundation installation has been shut down due to the presence of a North Atlantic right whale,
pile driving must not restart until the North Atlantic right whale has neither been visually or
acoustically detected by PSOs and PAM operators for 30 minutes. Upon re-starting pile driving,
soft-start protocols must be followed if pile driving has ceased for 30 minutes or longer.
The clearance and shutdown zone sizes vary by species and are shown in tables 36 and
37. Avangrid is allowed to request modification to these zone sizes pending results of SFV (see
the regulatory text at the end of this rule). Any changes to zone size would be part of adaptive
management and would require NMFS’ approval. The 12 km PAM monitoring zone for North
Atlantic right whales has been carried forward from the proposed rule into this final rule. The
clearance and shutdown zones for North Atlantic right whales have been increased to any visual
distance by foundation installation PSOs and any acoustic detection within the 12-km PAM
monitoring zone. The increase to these zones also increases protections for North Atlantic right
whales during impact pile driving.

In addition to the clearance and shutdown zones that would be monitored both visually
and acoustically, NMFS is requiring Avangrid to establish a minimum visibility zone during
foundation installation activities to ensure both visual and acoustic methods are used in tandem
to detect marine mammals resulting in maximum detection capability. No minimum visibility
zone is required for UXO/MEC detonation as the entire visual clearance zone must be clear
given the potential for lung and GI injury. The minimum visibility zone for foundation
installation activities (pile driving and drilling) would extend from the location of the pile being
driven out to 2.1 km (monopiles) and 3.4 km (jacket). This value corresponds to just greater than
the modeled maximum ER95% distances to the Level A harassment threshold for North Atlantic
right whales, assuming 10 dB of attenuation. The entire minimum visibility zone must be visible
for a full 60 minutes immediately prior to commencing pile driving and drilling. The entire
clearance zone must be visible for a full 60 minutes immediately prior to commencing
UXO/MEC detonation.
For HRG surveys, there are no mitigation measures prescribed for sound sources
operating at frequencies greater than 180 kHz, as these would be expected to fall outside of
marine mammal hearing ranges and would not result in harassment. However, all HRG survey
vessels would be subject to the aforementioned vessel strike avoidance measures described
earlier in this section. Furthermore, due to the frequency range and characteristics of some of the
sound sources associated with lesser impacts, shutdown, clearance, and ramp-up procedures are
not planned to be conducted during HRG surveys utilizing only non-impulsive sources (e.g.,
other parametric sub-bottom profilers). Shutdown, clearance, and ramp-up procedures are
planned to be conducted during HRG surveys utilizing SBPs and other non-parametric subbottom profilers (planned survey equipment are in table 31). PAM would not be required during
HRG surveys. While NMFS agrees that PAM can be an important tool for augmenting detection
capabilities in certain circumstances, its utility in further reducing impacts during HRG survey
activities is limited.

Avangrid will be required to implement a 30-minute clearance period of the clearance
zones (table 36) immediately prior to the commencing of the survey, or when there is more than
a 30-minute break in survey activities and PSOs have not been actively monitoring. If a marine
mammal is observed within a clearance zone during the clearance period, ramp up (described
below) may not begin until the animal(s) have been observed voluntarily exiting its respective
clearance zone or until an additional time period has elapsed with no further sighting (i.e., 15
minutes for small odontocetes and pinnipeds, and 30 minutes for all other species). When the
clearance process has begun in conditions with good visibility, including via the use of night
vision equipment (i.e., infrared (IR)/thermal camera), and the Lead PSO has determined that the
clearance zones are clear of marine mammals, survey operations would be allowed to commence
(i.e., no delay is required) despite periods of inclement weather and/or loss of daylight.
Once the survey has commenced, Avangrid would be required to shut down SBPs if a
marine mammal enters a respective shutdown zone (table 36). In cases where the shutdown
zones become obscured for brief periods due to inclement weather, survey operations would be
allowed to continue (i.e., no shutdown is required) so long as no marine mammals have been
detected. The use of SBPs will not be allowed to commence or resume until the animal(s) has
been confirmed to have left the shutdown zone or until a full 15 minutes (for small odontocetes
and seals) or 30 minutes (for all other marine mammals) have elapsed with no further sighting.
Any large whale sighted by a PSO within 1,000 m of the SBPs that cannot be identified as a nonNorth Atlantic right whale would be treated as if it were a North Atlantic right whale for the
purposes of mitigation implementation.
Once the survey has commenced, Avangrid would be required to shut down SBPs if a
marine mammal enters a respective shutdown zone (table 36). In cases when the shutdown zones
become obscured for brief periods due to inclement weather, survey operations would be allowed
to continue (i.e., no shutdown is required) so long as no marine mammals have been detected.
The use of SBPs will not be allowed to commence or resume until the animal(s) has been

confirmed to have left the shutdown zone or until a full 15 minutes (for small odontocetes and
seals) or 30 minutes (for all other marine mammals) have elapsed with no further sighting. Any
large whale sighted by a PSO within 1,000 m of the SBPs that cannot be identified as a nonNorth Atlantic right whale would be treated as if it were a North Atlantic right whale.
If a SBP is shut down for reasons other than mitigation (e.g., mechanical difficulty) for
less than 30 minutes, it would be allowed to be activated again without ramp-up only if (1) PSOs
have maintained constant observation, and (2) no additional detections of any marine mammal
occurred within the respective shutdown zones. If a SBP was shut down for a period longer than
30 minutes, then all clearance and ramp-up procedures would be required, as previously
described.
For any other in-water construction heavy machinery activities (e.g., trenching, cable
laying, etc.), if a marine mammal is on a path towards and about to enter or comes within 10 m
(32.8 ft) of equipment, Avangrid is required to cease operations until the marine mammal has
moved more than 10 m on a path away from the activity to avoid direct interaction with
equipment.
Table 36 – Minimum Visibility, Clearance, Shutdown, and Level B Harassment Zones During
Foundation Installation and HRG
Activity

Marine
Mammal

Minimum
Visibility Zone
(m)4

Other baleen
and sperm
Small whales
and dolphins

Visual and
Acoustic
Shutdown Zone
(m)6

Acoustic
Monitoring
Zone (m)

Any distance visual detection from
PSOs, any acoustic detection within
12-km acoustic monitoring zone

North Atlantic
right whale

Monopile1

Visual and
Acoustic
Clearance Zone
(m)5

3,300

Vessel
Separation Zone
(m)

2,700

100
12,0007

2,100

200

Harbor porpoise

250

Seals

200

Any distance visual detection from
PSOs, any acoustic detection within
12-km acoustic monitoring zone

North Atlantic
right whale
Other baleen
and sperm
Jacket2

HRG3

4,900

4,100

200

Harbor porpoise

250

Seals

1,000

50

North Atlantic
right whale

500

500

100

Small whales
and dolphins

All other ESA
All other nonESA

3,400

100
12,0007

N/A

100
1 – The zones for monopiles apply to all impact pile driving, vibratory pile driving, and drilling activities and are
based on the largest distances to Level A harassment ER95% thresholds across the monopile and hammer sizes (i.e.,
12m, 13m, 5,000 kJ, 6,000 kJ).The exact size may be modified through adaptive management should SFV
demonstrate noise levels are lower or higher than expected. New zone sizes will be based on the definition provided
in footnotes 5 and 6.
2 – The zones for the 4-m jacket pin piles apply to impact pile driving, vibratory pile driving, and drilling activities
and are based on the largest distances to Level A harassment ER95% thresholds. The exact zone size may be modified
through adaptive management should SFV demonstrate noise levels are lower or higher than expected. New zone
sizes will be based on the definition provided in footnotes 5 and 6.
3 – HRG zones are limited to visual clearance and shutdown zones as PAM is not required. Clearance and shutdown
zones apply only when operating sound sources covered under the specified activities that may result in take (i.e.,
SBPs).
4 – The minimum visibility zone is based on the largest distance to the Level A harassment ER95% for low-frequency
cetaceans, not including fin whales, rounded up for PSO clarity. The entire minimum visibility zone must be visible
for a full 60 minutes immediately prior to commencing pile driving and drilling.
5 – The clearance zone for “other baleen and sperm” is based on the largest distance to the Level A harassment
ER95% of the species group plus a 20 percent increase and then rounded up for PSO clarity. The clearance zones for
the other species groups, not including North Atlantic right whale, is set as a minimum of 200 m for those species
whose distance to Level A harassment was less than 200 m so as to place the clearance zone outside the NAS. For
harbor porpoise, Avangrid proposed, and NMFS accepted, a zone of 250 m though the distance to Level A
harassment ER95% was modeled at less than 200 m, therefore, no additional increase is warranted for the clearance
zone. For seals, as its distance to Level A harassment was more than 200 m, the clearance zone was set as the largest
distance to the Level A harassment ER95% of the species group plus a 20 percent increase and then rounded up for
PSO clarity.
6 – The shutdown zone for “other baleen and sperm” is based on the largest distance to the Level A harassment
ER95% then rounded up for PSO clarity. The shutdown zones for the other species groups, not including North
Atlantic right whale, is set as a minimum of 200 m for those species whose distance to Level A harassment was less
than 200 m so as to place the shutdown zone outside the NAS. For harbor porpoise, Avangrid proposed, and NMFS
accepted, a zone of 250 m though the distance to Level A harassment ER95% was modeled at less than 200 m. For
seals during jacket foundation installation, the distance to Level A harassment was more than 200 m (790 m) so the
shutdown zone was rounded up to 800 m.
7- The PAM system must be designed to detect all marine mammals to the maximum extent practicable, maximize
baleen whale detections, and must be capable of detecting North Atlantic right whales at 12 km. NMFS recognizes
that other marine mammals (e.g., harbor porpoise) may not be detected at 12 km.

Table 37 – Clearance, Level A Harassment, and Level B Harassment Zones During UXO/MEC
Detonations, by Charge Weight and Assuming 10 dB of Sound Attenuation
Low-frequency
cetaceans

Mid-frequency
cetaceans

High-frequency
cetaceans

Phocid Pinnipeds

Level A harassment
(m)

50

1,820

Level B harassment
(m)

2,82

6,160

1,470

Clearance Zone
(m)a, b, c

2,500*

2,500

1,000

Level A harassment
(m)

75

2,590

Level B harassment
(m)

4,680

8,000

2,350

Clearance Zone
(m)a, b, c

4,000*

4,000

1,500

Level A harassment
(m)

1,730

3,900

Level B harassment
(m)

7,490

1,240

10,300

3,820

Clearance Zone
(m)a, b, c

6,000*

1,000

6,000

3,000

Level A harassment
(m)

2,970

5,400

1,220

Level B harassment
(m)

10,500

2,120

12,900

5,980

Clearance Zone
(m)a, b, c

9,000*

1,500

9,000

4,000

Level A harassment
(m)

3,780

6,200

1,600

Level B harassment
(m)

11,900

2,550

14,100

7,020

Clearance Zone
(m)a, b, c

10,000*

2,000

10,000

5,000

UXO/MEC Charge Weights

E4 (2.3 kg)

E6 (9.1 kg)

E8 (45.5 kg)

E10 (227 kg)

E12 (454 kg)

* The clearance zone size for the North Atlantic right whale is “any distance”. Detonation must not occur if a North
Atlantic right whale is visually or acoustically detected at any distance from the detonation site.
a – The clearance zones, which are visually and acoustically monitored, presented here for the Level B harassment
thresholds were derived based on an approximate proportion of the size of the Level B harassment (TTS) isopleth.
The clearance zone sizes are contingent on Avangrid being able to demonstrate that they can identify charge weights
in the field; if they cannot identify the charge weight sizes in the field then Avangrid would need to assume the E12
charge weight size for all detonations and must implement the E12 clearance zone. No minimum visibility zone is
required for UXO/MEC detonation as the entire clearance zone must be visually clear.
b – Some of the zones have been rounded for PSO clarity.
c- The exact zone sizes may be modified through adaptive management should SFV demonstrate noise levels are
lower or higher than expected.

NMFS also notes that for any UXO/MECs that require removal, Avangrid is required to
implement the ALARP process. This process would require Avangrid to undertake “lift-andshift” (i.e., physical removal) and then lead up to in situ disposal, which could include low-order
(deflagration) to high-order (detonation) methods of removal. Another potential approach
involves the cutting of the UXO/MEC to extract any explosive components. Implementing the
ALARP approach would minimize potential impacts to marine mammals as UXOs/MECs would
only be detonated as a last resort.
Soft-Start/Ramp-Up
The use of a soft-start or ramp-up procedure is believed to provide additional protection
to marine mammals by warning them or providing them with a chance to leave the area, prior to
the hammer or HRG equipment operating at full capacity. Soft-start typically involves initiating
hammer operation at a reduced energy level relative to full operating capacity followed by a
waiting period. Typically, NMFS requires a soft-start procedure of the applicant performing four
to six strikes per minute at 10 to 20 percent of the maximum hammer energy, for a minimum of
20 minutes. For foundation installation, NMFS notes that it is difficult to specify a reduction in
energy for any given hammer because of variation across drivers and installation conditions. The
final methodology will be developed by Avangrid, in consultation with NMFS, considering final
design details including site-specific soil properties and other considerations. A general soft-start
requirement for impact pile driving is incorporated into the regulations. HRG survey operators
are required to ramp-up sources when the acoustic sources are used unless the equipment
operates on a binary on/off switch. The ramp-up would involve starting from the smallest setting
and gradually increasing to the operating level over a period of approximately 30 minutes.
Soft-start and ramp-up will be required at the beginning of each day’s activity and at any
time following a cessation of activity of 30 minutes or longer. Prior to soft-start or ramp-up
beginning, the operator must receive confirmation from the PSO that the clearance zone is clear
of any marine mammals.

Fishery Monitoring Surveys
While the likelihood of Avangrid’s fishery monitoring surveys impacting marine
mammals is minimal, NMFS requires Avangrid to adhere to gear and vessel mitigation measures
to reduce potential impacts to the extent practicable. In addition, all crew undertaking the fishery
monitoring survey activities are required to receive protected species identification training prior
to activities occurring and attend the aforementioned onboarding training. The specific
requirements that NMFS has set for the fishery monitoring surveys can be found in the
regulatory text at the end of this rule.
Based on our evaluation of the mitigation measures, as well as other measures considered
by NMFS, NMFS has determined that these measures will provide the means of affecting the
least practicable adverse impact on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar significance.
Monitoring and Reporting
As noted in the Changes from the Proposed to Final Rule section, we have added,
modified, or clarified a number of monitoring and reporting measures since the proposed rule.
These changes are described in detail below. Since the proposed rule, we have increased the
number of required active PSOs per platform (i.e., foundation installation vessel, dedicated PSO
vessels) during foundation installation activities from two to three PSOs. This requirement will
increase monitoring effort to promote more effective detection of marine mammals during
foundation installation activities. In addition, we have added specific requirements for SFV
monitoring.
In order to promulgate a rulemaking for an activity, section 101(a)(5)(A) of the MMPA
states that NMFS must set forth requirements pertaining to the monitoring and reporting of such
taking. The MMPA implementing regulations at 50 CFR 216.104(a)(13) indicate that requests
for authorizations must include the suggested means of accomplishing the necessary monitoring
and reporting that will result in increased knowledge of the species and of the level of taking or

impacts on populations of marine mammals that are expected to be present in the action area.
Effective reporting is critical both to compliance as well as ensuring that the most value is
obtained from the required monitoring.
Monitoring and reporting requirements prescribed by NMFS should contribute to
improved understanding of one or more of the following:
●

Occurrence of marine mammal species or stocks in the area in which take is anticipated

(e.g., presence, abundance, distribution, density);
●

Nature, scope, or context of likely marine mammal exposure to potential

stressors/impacts (i.e., individual or cumulative, acute or chronic), through better understanding of: (1)
action or environment (e.g., source characterization, propagation, ambient noise); (2) affected species
(e.g., life history, dive patterns); (3) co-occurrence of marine mammal species with the action; or (4)
biological or behavioral context of exposure (e.g., age, calving or feeding areas);
●

Individual marine mammal responses (i.e., behavioral or physiological) to acoustic

stressors (i.e., acute, chronic, or cumulative), other stressors, or cumulative impacts from multiple
stressors;
●

How anticipated responses to stressors impact either: (1) long-term fitness and survival of

individual marine mammals; or (2) populations, species, or stocks;
●

Effects on marine mammal habitat (e.g., marine mammal prey species, acoustic habitat,

or other important physical components of marine mammal habitat); and/or
●

Mitigation and monitoring effectiveness.

Separately, monitoring is also regularly used to support mitigation implementation (i.e.,
mitigation monitoring) and monitoring plans typically include measures that both support
mitigation implementation and increase our understanding of the impacts of the activity on
marine mammals.
During the planned activities, visual monitoring by NMFS-approved PSOs would be
conducted before, during, and after all impact pile driving, vibratory pile driving, drilling,

UXO/MEC detonations, and HRG surveys. PAM would be also conducted during impact pile
driving, vibratory pile driving, drilling, and UXO/MEC detonations. Visual observations and
acoustic detections would be used to support the activity-specific mitigation measures (e.g.,
clearance zones). To increase understanding of the impacts of the activity on marine mammals,
PSOs must record all incidents of marine mammal occurrence at any distance from the
foundation installation locations (i.e., location of impact pile driving, vibratory pile driving, and
drilling), near the HRG acoustic sources, and during UXO/MEC detonations. PSOs would
document all behaviors and behavioral changes, in concert with distance from an acoustic
source. Further, SFV during foundation installation and UXO/MEC detonation is required to
ensure compliance and that the potential impacts are within the bounds of that analyzed. The
required monitoring, including PSO and PAM Operator qualifications, is described below,
beginning with PSO measures that are applicable to all the aforementioned activities and PAM
(for specific activities).
Protected Species Observer and PAM Operator Requirements
Avangrid is required to employ NMFS-approved PSOs and PAM operators. PSOs are
trained professionals who are tasked with visually monitoring for marine mammals during pile
driving, drilling, UXO/MEC detonation, and HRG surveys. The primary purpose of a PSO is to
carry out the monitoring, collect data, and, when appropriate, call for the implementation of
mitigation measures. In addition to visual observations, NMFS requires Avangrid to conduct
PAM by PAM operators during impact pile driving, vibratory pile driving, drilling, UXO/MEC
detonation, and vessel transit.
The inclusion of PAM, which would be conducted by NMFS-approved PAM operators,
following standardized measurement, processing methods, reporting metrics, and metadata
standards for offshore wind, combined with visual data collection, is a valuable way to provide
the most accurate record of species presence as possible. These two monitoring methods are well
understood to provide best results when combined together (e.g., Barlow and Taylor, 2005; Clark

et al., 2010; Gerrodette et al., 2011; Van Parijs et al., 2021). Acoustic monitoring, in addition to
visual monitoring, increases the likelihood of detecting marine mammals within the shutdown
and clearance zones of project activities, which when applied in combination of required
shutdowns helps to further reduce the risk of marine mammals being exposed to sound levels
that could otherwise result in acoustic injury or more intense behavioral harassment.
The exact configuration and number of PAM systems depends on the size of the zone(s)
being monitored, the amount of noise expected in the area, and the characteristics of the signals
being monitored. More closely-spaced hydrophones would allow for more directionality and
range to the vocalizing marine mammals. Larger baleen cetacean species (i.e., mysticetes), which
produce loud and lower-frequency vocalizations, may be able to be heard with fewer
hydrophones spaced at greater distances. However, smaller cetaceans (e.g., mid-frequency
delphinids; odontocetes) may necessitate more hydrophones and to be spaced closer together
given the shorter range of the shorter, mid-frequency acoustic signals (e.g., whistles and
echolocation clicks). As there are no “perfect fit” single-optimal-array configurations, these setups would need to be considered on a case-by-case basis during the PAM Plan review.
NMFS does not formally administer any PSO or PAM operator training programs or
endorse specific providers but will approve PSOs and PAM operators that have successfully
completed courses that meet the curriculum and training requirements referenced below and
further specified in the regulatory text at the end of this rule. PSOs can act as PAM operators or
visual PSOs (but not simultaneously) as long as they demonstrate that their training and
experience are sufficient to perform each task.
NMFS will provide PSO and PAM operator approvals to ensure that PSOs and PAM
operators have the necessary training and/or experience to carry out their duties competently. In
order for PSOs and PAM operators to be approved, NMFS must review and approve PSO and
PAM operator resumes indicating successful completion of an acceptable training course. PSOs
and PAM operators must have previous experience observing marine mammals and must have

the ability to work with all required and relevant software and equipment. NMFS may approve
PSOs and PAM operators as conditional or unconditional. A conditional approval may be given
to one who is trained but has not yet attained the requisite experience. An unconditional approval
is given to one who is trained and has attained the necessary experience. The specific
requirements for conditional and unconditional approval can be found in the regulatory text at
the end of this rule.
Conditionally-approved PSOs and PAM operators must be paired with an
unconditionally-approved PSO (or PAM operator, as appropriate) to ensure that the quality of
marine mammal observations and data recording is kept consistent. Additionally, activities
requiring PSO and/or PAM operator monitoring must have a lead on duty. The visual PSO field
team, in conjunction with the PAM team, (i.e., together, the marine mammal monitoring team),
would have a lead member (designated as the “Lead PSO” or “Lead PAM operator”) who would
be required to meet the unconditional approval standard.
Although PSOs and PAM operators must be approved by NMFS, third-party observer
providers and/or companies seeking PSO and PAM operator staffing should expect that those
having satisfactorily completed acceptable training and with the requisite experience (if required)
will be quickly approved. Avangrid is required to request PSO and PAM operator approvals 60
days prior to those personnel commencing work. An initial list of previously approved PSO and
PAM operators must be submitted by Avangrid at least 30 days prior to the start of the Project.
Should Avangrid require additional PSOs or PAM operators throughout the Project, Avangrid
must submit a subsequent list of pre-approved PSOs and PAM operators to NMFS at least 15
days prior to planned use of that PSO or PAM operator. A PSO may be trained and/or
experienced as both a PSO and PAM operator and may perform either duty, pursuant to
scheduling requirements.
A minimum number of PSOs would be required to actively observe for the presence of
marine mammals during certain project activities, generally speaking, with more PSOs being

required as the mitigation zone sizes increase. A minimum number of PAM operators would be
required to actively monitor for the presence of marine mammals during foundation installation
and UXO/MEC detonations. The types of equipment required (e.g., big eyes on the pile driving
vessel) are also designed to increase marine mammal detection capabilities. Specifics on these
types of requirements can be found in the regulations at the end of this rule.
At least three PSOs must be on duty at a time on the foundation installation
vessel/platform and UXO/MEC monitoring platform. A minimum of three PSOs must be active
on a dedicated PSO vessel. If a dedicated PSO vessel is selected, the vessel must be located at
the best vantage point to observe and document marine mammal sightings in proximity to the
clearance and, if applicable, shutdown zones.
At least one PSO must be on-duty during HRG surveys conducted during daylight hours;
and at least two PSOs must be on-duty during HRG surveys conducted during nighttime.
As part of their monitoring duties, PSOs and PAM operators are responsible for data
collection. The data collected by PSO and PAM operators and subsequent analysis provide the
necessary information to inform an estimate of the amount of take that occurred during the
Project, better understand the impacts of the Project on marine mammals, address the
effectiveness of monitoring and mitigation measures, and to adaptively manage activities and
mitigation in the future. Data reported includes information on marine mammal sightings (e.g.,
numbers of animals and their behavior), activity occurring at time of sighting, monitoring
conditions, and if mitigative actions were taken. Specific data collection requirements are
contained within the regulations at the end of this rule.
Avangrid is required to submit a Foundation Installation Monitoring Plan and a PAM
Plan to NMFS 180 days in advance of foundation installation activities. The Plan must include
details regarding PSO and PAM monitoring protocols and equipment proposed for use, as
described in the regulatory text at the end of this rule. NMFS must approve the plan prior to
foundation installation activities commencing. Specific details on NMFS’ PSO or PAM operator

qualifications and requirements can be found in 50 CFR part 217, subpart GG, set out at the end
of this rule.
Sound Field Verification
Previously in the proposed rule, Avangrid had to conduct SFV measurements during all
UXO/MEC detonations, and all pile driving and drilling activities associated with the installation
of, at minimum, the first three monopile foundations. SFV measurements must continue until at
least three consecutive piles demonstrate distances to thresholds that are at or below those
modeled assuming 10 dB of attenuation. Subsequent SFV measurements are also required should
larger piles be installed or additional piles be driven that are anticipated to produce longer
distances to harassment isopleths than those previously measured (e.g., higher hammer energy,
greater number of strikes, etc.).
For the final rule, NMFS has expanded this requirement for SFV during foundation
installation to align with the BiOp. At minimum, Thorough SFV must be conducted in: the first
construction year for the first three monopiles installed with only an impact hammer; the first
three monopiles installed with a vibratory hammer followed by an impact hammer; the first two
jacket foundations (all piles) installed; the first foundation (regardless of type) where drilling
(i.e., relief drilling) is used; all monopiles and the first jacket foundation (all piles) installed in
December (winter sound speed profile); and, the first foundation for any foundation scenarios
that were modeled for the exposure analysis (e.g., rated hammer energy, number of strikes,
representative location) that does not fall into one of the previously listed categories (e.g., if the
first two jacket foundation are installed with an impact hammer only, Thorough SFV would be
required for the first jacket foundation installed with vibratory and impact pile driving). Without
exception, Thorough SFV is required for all UXO/MEC detonations.
After the first construction year, if there are no changes to the pile driving equipment
(i.e., same hammer, same Noise Attenuation System) – the first monopile and first jacket
foundation (all piles) must have Thorough SFV; if changes to the equipment (e.g., different

hammer, different noise attenuation system) – the Thorough SFV requirements from the first
construction year apply. Any foundation type or technique included in the requirements for the
first construction year that was not installed until a subsequent construction year (e.g., if drilling
is not used until year 2 or 3, the first foundation where drilling is used must have Thorough
SFV). During Thorough SFV, installation of the next foundation (of the same type/foundation
method) may not proceed until Avangrid has reviewed the initial results from the Thorough SFV
and determined that there were no exceedances of any distances to the identified thresholds
based on modeling assuming 10 dB of attenuation.
If any of the Thorough SFV measurements from any pile indicate that the distance to any
isopleth of concern for any species is greater than those modeled assuming 10 dB of attenuation,
Avangrid must notify NMFS within 24 hours of reviewing the Thorough SFV measurements and
must implement the measures described in detail in the regulatory text at the end of this final rule
for the next pile of the same type/installation methodology, as applicable.
Abbreviated SFV monitoring must be performed on all foundation installations for which
the complete SFV monitoring described above is not conducted. In addition, SFV measurements
must be conducted upon commencement of turbine operations to estimate turbine operational
source levels, in accordance with a NMFS-approved Foundation Installation Pile Driving SFV
Plan. The measurements and reporting associated with SFV can be found in the regulatory text at
the end of this rule. The requirements are extensive to ensure monitoring is conducted
appropriately and the reporting frequency is such that Avangrid is required to make adjustments
quickly (e.g., ensure bubble curtain hose maintenance, check bubble curtain air pressure supply,
add additional sound attenuation, etc.) to ensure marine mammals are not experiencing noise
levels above those considered in this analysis. For recommended SFV protocols for impact pile
driving, please consult International Organization for Standardization (ISO) 18406, “Underwater
acoustics—Measurement of radiated underwater sound from percussive pile driving” (2017).

Reporting
Prior to any construction activities occurring, Avangrid will provide a report to NMFS
Office of Protected Resources that demonstrates that all Avangrid personnel, including the vessel
crews, vessel captains, PSOs, and PAM operators, have completed all required trainings.
NMFS will require standardized and frequent reporting from Avangrid during the life of
the regulations and the LOA. All data collected relating to the Project will be recorded using
industry-standard software (e.g., Mysticetus or a similar software) installed on field laptops
and/or tablets. Avangrid is required to submit weekly, monthly, annual, situational, and final
reports. The specifics of what we require to be reported can be found in the regulatory text at the
end of this final rule.
Weekly Report – During foundation installation activities, Avangrid would be required to
compile and submit weekly marine mammal monitoring reports for foundation installation
activities to NMFS Office of Protected Resources that document the daily start and stop of all
pile-driving and drilling activities, the start and stop of associated observation periods by PSOs,
details on the deployment of PSOs, a record of all detections of marine mammals (acoustic and
visual), any mitigation actions (or if mitigation actions could not be taken, provide reasons why),
and details on the noise abatement system(s) (e.g., system type, distance deployed from the pile,
bubble rate, etc.), and abbreviated SFV results. Weekly reports will be due on Wednesday for the
previous week (Sunday to Saturday). The weekly reports are also required to identify which
turbines become operational and when (a map must be provided). Once all foundation pile
installation is complete, weekly reports would no longer be required.
Monthly Report – Avangrid is required to compile and submit monthly reports to NMFS
Office of Protected Resources that include a summary of all information in the weekly reports,
including project activities carried out in the previous month, vessel transits (number, type of
vessel, and route), number of piles installed, number of UXO/MECs detonated, all detections of
marine mammals, and any mitigative actions taken. Monthly reports would be due on the 15th of

the month for the previous month. The monthly report would also identify which turbines
become operational and when, and a map must be provided. Once all foundation pile installation
is complete, monthly reports would no longer be required.
Annual Reporting – Avangrid is required to submit an annual marine mammal monitoring
(both PSO and PAM) report to NMFS Office of Protected Resources by March 31, annually,
describing, in detail, all of the information required in the monitoring section above for the
previous calendar year. A final annual report must be prepared and submitted within 30 calendar
days following receipt of any NMFS comments on the draft report.
Final Reporting – Avangrid must submit its draft 5-year report(s) to NMFS Office of
Protected Resources. The report must contain, but is not limited to, a description of activities
conducted (including GIS files where relevant), and all visual and acoustic monitoring, including
SFV and monitoring effectiveness, conducted under the LOA within 90 calendar days of the
completion of activities occurring under the LOA. A final 5-year report must be prepared and
submitted within 60 calendar days following receipt of any NMFS comments on the draft report.
Situational Reporting – Specific situations encountered during the development of the
Project require immediate reporting. For instance, if a North Atlantic right whale is observed at
any time by PSOs or project personnel, the sighting must be immediately reported to NMFS, or,
if not feasible, as soon as possible and no longer than 24 hours after the sighting. If a North
Atlantic right whale is acoustically detected at any time via a project-related PAM system, the
detection must be reported as soon as possible and no longer than 24 hours after the detection to
NMFS via the 24-hour North Atlantic right whale Detection Template
(https://www.fisheries.noaa.gov/resource/document/passive-acoustic-reporting-systemtemplates). Calling the hotline is not necessary when reporting PAM detections via the template.
If a sighting of a stranded, entangled, injured, or dead marine mammal occurs, the
sighting would be reported within 24 hours to NMFS Office of Protected Resources, the NMFS
Greater Atlantic Stranding Coordinator for the New England/Mid-Atlantic area (866-755-6622)

in the Northeast Region (if in the Southeast Region (NC to FL), contact 877-942-5343), and the
U.S. Coast Guard within 24 hours.
In the event of a vessel strike of a marine mammal by any vessel associated with the
Project or if project activities cause a non-auditory injury or death of a marine mammal,
Avangrid must immediately report the incident to NMFS. If in the Greater Atlantic Region
(Maine to Virginia), Avangrid must call the NMFS Greater Atlantic Stranding Hotline.
Separately, Avangrid must also and immediately report the incident to NMFS Office of Protected
Resources and GARFO. Avangrid must immediately cease all on-water activities, including pile
driving, until NMFS Office of Protected Resources is able to review the circumstances of the
incident and determine what, if any, additional measures are appropriate to ensure compliance
with the terms of the MMPA. NMFS Office of Protected Resources may impose additional
measures covered in the adaptive management provisions of this rule to minimize the likelihood
of further prohibited take and ensure MMPA compliance. Avangrid may not resume their
activities until notified by NMFS.
In the event of any lost gear associated with the fishery surveys, Avangrid must report to
the GARFO as soon as possible or within 24 hours of the documented time of missing or lost
gear. This report must include information on any markings on the gear and any efforts
undertaken or planned to recover the gear.
The specifics of what NMFS Office of Protected Resources requires to be reported is
listed at the end of this rulemaking in the regulatory text.
Sound Field Verification – Avangrid is required to submit interim SFV reports after each
foundation installation and UXO/MEC detonation monitored as soon as possible but within 48
hours for Thorough SFV. Abbreviated SFV reports must be included in the weekly monitoring
reports. A final SFV report for all foundation installations and UXO/MEC detonations will be
required within 90 days following completion of acoustic monitoring.

Adaptive Management
These regulations contain an adaptive management component. Our understanding of the
effects of offshore wind construction activities (e.g., acoustic stressors) on marine mammals
continues to evolve, which makes the inclusion of an adaptive management component both
valuable and necessary within the context of 5-year regulations.
The monitoring and reporting requirements in this final rule will provide NMFS with
information that helps us to better understand the impacts of the Project’s activities on marine
mammals and informs our consideration of whether any changes to mitigation and monitoring
are appropriate. The use of adaptive management allows NMFS to consider new information and
modify mitigation, monitoring, or reporting requirements, as appropriate, with input from
Avangrid regarding practicability, if such modifications will have a reasonable likelihood of
more effectively accomplishing the goal of the measures.
The following are some of the possible sources of new information to be considered
through the adaptive management process: (1) results from monitoring reports, including the
weekly, monthly, situational, and annual reports required; (2) results from research on marine
mammals, noise impacts, or other related topics; and (3) any information that reveals that marine
mammals may have been taken in a manner, extent, or number not authorized by these
regulations or subsequent LOA. Adaptive management decisions may be made at any time, as
new information warrants it. NMFS may consult with Avangrid regarding the practicability of
the modifications.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the specified activity
that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the
species or stock through effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse effects on annual rates of
recruitment or survival (i.e., population-level effects). An estimate of the number of takes alone

is not enough information on which to base an impact determination. In addition to considering
estimates of the number of marine mammals that might be “taken” by mortality, serious injury,
or by Level A harassment and Level B harassment, we consider other factors, such as the likely
nature of any behavioral responses (e.g., intensity, duration), the context of any such responses
(e.g., critical reproductive time or location, migration), as well as effects on habitat, and the
likely effectiveness of mitigation. We also assess the number, intensity, and context of estimated
takes by evaluating this information relative to population status. Consistent with the 1989
preamble for NMFS’ implementing regulations (54 FR 40338, September 29, 1989), the impacts
from other past and ongoing anthropogenic activities are incorporated into this analysis via their
impacts on the environmental baseline (e.g., as reflected in the regulatory status of the species,
population size and growth rate where known, ongoing sources of human-caused mortality, or
ambient noise levels).
In the Estimated Take section, we estimated the maximum number of takes by Level A
harassment and Level B harassment that are reasonably expected to occur from the specified
activities based on the methods described. The impact that any given take would have is
dependent on many case-specific factors that need to be considered in the negligible impact
analysis (e.g., the context of behavioral exposures such as duration or intensity of a disturbance,
the health of impacted animals, the status of a species that incurs fitness-level impacts to
individuals, etc.). In this final rule, we evaluate the likely impacts of the enumerated harassment
takes that may be authorized in the context of the specific circumstances surrounding these
predicted takes. We also collectively evaluate this information, as well as other more taxaspecific information and mitigation measure effectiveness, in group-specific discussions that
support our negligible impact conclusions for each stock. As described above, no serious injury
or mortality is expected or may be authorized for any species or stock.
The Description of the Specified Activities section describes Avangrid’s specified
activities that may result in take of marine mammals and an estimated schedule for conducting

those activities. Avangrid has provided a realistic construction schedule although we recognize
schedules may shift for a variety of reasons (e.g., weather or supply delays). However, the total
amount of take would not exceed the 5-year totals and maximum annual total in any given year
indicated in tables 33 and 35, respectively.
We base our analysis and negligible impact determination on the maximum number of
takes expected to occur annually and across the 5-year effective period of these regulations, as
well as extensive qualitative consideration of other contextual factors that influence the severity
and nature of impact the takes have on the affected individuals and the number and the number
of individuals affected. As stated before, the number of takes, both maximum annual and 5-year
total, alone are only a part of the analysis.
To avoid repetition, we provide some general analysis in this Negligible Impact Analysis
and Determination section that applies to all the species listed in table 2, given that some of the
anticipated effects of Avangrid’s construction activities on marine mammals are expected to be
relatively similar in nature. Then, we subdivide into more detailed discussions for mysticetes,
odontocetes, and pinnipeds which have broad life-history traits that support an overarching
discussion of some factors considered within the analysis for those groups (e.g., habitat-use
patterns, high-level differences in feeding strategies).
Last, we provide a negligible impact determination for each species or stock, providing
species or stock-specific information or analysis, where appropriate, for example, for North
Atlantic right whales, given their population status. Organizing our analysis by grouping species
or stocks that share common traits or that would respond similarly to effects of Avangrid’s
activities and then providing species- or stock-specific information allows us to avoid duplication
while ensuring that we have analyzed the effects of the specified activities on each affected
species or stock. It is important to note that in the group or species sections, we base our
negligible impact analysis on the maximum annual take that is predicted under the 5-year rule
and that the negligible impact determination also examines the total taking over the 5-year

period; however, the majority of the impacts are associated with WTG foundation and ESP
foundation installation, which would occur largely during years 2 and 3 (2026 through 2027).
The estimated take in the other years is expected to be notably less, which is reflected in the total
take that would be allowable under the rule (table 33).
As described previously, no serious injury or mortality is anticipated or may be
authorized in any LOA issued under this rule. Non-auditory injury (e.g., lung injury or
gastrointestinal injury from UXO/MEC detonation) is also not anticipated and would not be
authorized in any LOA issued under this rule. Any Level A harassment that may be authorized
would be in the form of auditory injury (i.e., PTS).
The amount of harassment Avangrid has requested, and NMFS may authorize, is based
on exposure models that consider the outputs of acoustic source and propagation models and
other data such as frequency of occurrence or group sizes. Several conservative parameters and
assumptions are ingrained into these models, such as assuming forcing functions that consider
direct contact with piles (i.e., no cushion allowances) and application of the highest species
density monthly among the areas of interest (i.e., Lease Area, cable route) for each species was
applied to the exposure calculations. The exposure model results do not reflect any mitigation
measures (other than 10-dB sound attenuation) or avoidance response. The amount of take
requested and that may be authorized in a LOA also reflects careful consideration of other data
(e.g., group size data, PSO data). As described above, while current planning includes pile
installation divided between 2 or 3 years (Schedule A or Schedule B), the maximum annual take
estimates assume the maximum amount of take between the two schedules, to allow flexibility
should schedules change again. For all species, the amount of take that may be authorized
represents the maximum amount of Level A harassment and Level B harassment reasonably
expected to occur.

Behavioral Disturbance
In general, NMFS anticipates that impacts on an individual that has been harassed are
likely to be more intense when exposed to higher received levels and for a longer duration,
though this is in no way a strictly linear relationship for behavioral effects across species,
individuals, or circumstances, and less severe impacts result when exposed to lower received
levels for a brief duration. However, there is also growing evidence of the importance of
contextual factors such as distance from a source in predicting marine mammal behavioral
response to sound (i.e., sounds of a similar level emanating from a more distant source have been
shown to be less likely to evoke a response of equal magnitude (DeRuiter and Doukara, 2012;
Falcone et al., 2017)). As described in the “Potential Effects to Marine Mammals and their
Habitat” section of the proposed rule, the intensity and duration of any impact resulting from
exposure to the specified activities is dependent upon a number of contextual factors including,
but not limited to, sound source frequencies, whether the sound source is moving towards the
animal, hearing ranges of marine mammals, behavioral state at time of exposure, status of
individual exposed (e.g., reproductive status, age class, health) and an individual’s experience
with similar sound sources. Southall et al. (2021), Ellison et al. (2012), and Moore and Barlow
(2013), among others, emphasize the importance of context (e.g., behavioral state of the animals,
distance from the sound source) in evaluating behavioral responses of marine mammals to
acoustic sources.
Harassment of marine mammals may result in behavioral modifications (e.g., avoidance,
temporary cessation of foraging or communicating, changes in respiration or group dynamics,
masking) or may result in auditory impacts such as hearing loss. In addition, some of the lowerlevel physiological stress responses (e.g., change in respiration, change in heart rate) discussed
previously would likely co-occur with the behavioral modifications, although these physiological
responses are more difficult to detect and fewer data exist relating these responses to specific
received levels of sound. Takes by Level B harassment, then, may have a stress-related

physiological component as well; however, we would not expect the specified activities to
produce conditions of long-term and continuous exposure to noise leading to long-term
physiological stress responses in marine mammals that could affect reproduction or survival.
In the range of exposures that might result in Level B harassment (which by nature of the
way it is modeled/counted, occurs within 1 day), the less severe end might include exposure to
comparatively lower levels of a sound, at a greater distance from the animal, for a few or several
minutes. A less severe exposure of this nature could result in a behavioral response such as
avoiding an area that an animal would otherwise have chosen to move through or feed in for
some amount of time, or breaking off one or a few feeding bouts. More severe effects could
occur if an animal gets close enough to the source to receive a comparatively higher level, is
exposed continuously to one source for a longer time, or is exposed intermittently to different
sources throughout a day. Such effects might result in an animal having a more severe avoidance
response and leaving a larger area for a day or more or potentially losing feeding opportunities
for a day or more. Such severe behavioral effects are expected to occur infrequently, though, and
given the extensive mitigation and monitoring measures included in this rule, we expect severe
behavioral effects to be minimized.
Many species perform vital functions, such as feeding, resting, traveling, and socializing,
on a diel cycle (i.e., a 24-hour cycle). Behavioral reactions to noise exposure, when taking place
in a biologically important context, such as disruption of critical life functions, displacement, or
avoidance of important habitat, are more likely to be significant if they last more than 1 day or
recur on subsequent days (Southall et al., 2007) due to diel and lunar patterns in diving and
foraging behaviors observed in many cetaceans (Baird et al., 2008; Barlow et al., 2020;
Henderson et al., 2016; Schorr et al., 2014). It is important to note the water depth in the Project
Area is shallow (2 to 62 m) and deep diving species, such as sperm whales, are not expected to
be engaging in deep foraging dives when exposed to noise above NMFS harassment thresholds

during the specified activities. Therefore, we do not anticipate impacts to deep foraging behavior
to be impacted by the specified activities.
It is important to identify that the estimated number of takes for each stock does not
necessarily equate to the number of individual marine mammals expected to be harassed (which
may be lower, depending on the circumstances), but rather to the instances of take (e.g.,
exposures above the Level B harassment thresholds) that may occur. These instances may
represent either brief exposures of seconds for UXO/MEC detonations, seconds to minutes for
HRG surveys, or, in some cases, longer durations of exposure within (but not exceeding) a day
(e.g., pile driving). Some members of a species or stock may experience one exposure (i.e., be
taken on one day) as they move through an area, while other individuals may experience
recurring instances of take over multiple days throughout the year, in which case the number of
individuals taken is smaller than the total estimated take for that species or stock. In short, for
species that are more likely to be migrating through the area and/or for which only a
comparatively smaller number of takes are predicted (e.g., some of the mysticetes), it is more
likely that each take represents a different individual. However, for non-migrating species and/or
species with larger amounts of predicted take, we expect that the total anticipated takes represent
exposures of a smaller number of individuals of which some would be taken across multiple
days.
For Avangrid, impact pile driving of foundation piles is most likely to result in a higher
magnitude and severity of behavioral disturbance than other activities (i.e., drilling, vibratory
pile driving, UXO/MEC detonation, and HRG surveys). Impact pile driving has higher source
levels and longer durations (on an annual basis) than vibratory pile driving or drilling activities.
HRG survey equipment also produces much higher frequencies than pile driving, resulting in
minimal sound propagation. While UXO/MEC detonations may have higher source levels,
impact pile driving is planned for longer durations (i.e., a maximum of 10 UXO/MEC
detonations are planned, which would result in only instantaneous exposures).

While foundation installation impact pile driving is anticipated to be most impactful for
these reasons, impacts are minimized through implementation of mitigation measures, including
soft-starts, use of a sound attenuation system, the implementation of clearance zones that would
facilitate a delay of pile driving commencement, and the implementation of shutdown zones. For
example, given sufficient notice through the use of soft-start, marine mammals are expected to
move away from a sound source that is disturbing prior to becoming exposed to very loud noise
levels. The requirement to couple visual monitoring and PAM before and during all foundation
installation and UXO/MEC detonations would increase the overall capability to detect marine
mammals rather than when one method is used alone. Measures such as the requirement to apply
sound attention devices and implement clearance zones also apply to UXO/MEC detonation(s),
which also have the potential to elicit more severe behavioral reactions in the unlikely event that
an animal is relatively close to the explosion in the instant that it occurs; hence, severity of
behavioral responses are expected to be lower than would be the case without mitigation.
Occasional, milder behavioral reactions are unlikely to cause long-term consequences for
individual animals or populations, and even if some smaller subset of the takes are in the form of
a longer (several hours or a day) and more severe response, if they are not expected to be
repeated over numerous or sequential days, impacts to individual fitness are not anticipated.
Also, the effect of disturbance is strongly influenced by whether it overlaps with biologically
important habitats when individuals are present—avoiding biologically important habitats will
reduce the likelihood of more significant behavioral impacts, for example reduced or lost
foraging (Keen et al., 2021). Nearly all studies and experts agree that infrequent exposures of a
single day or less are unlikely to impact an individual’s overall energy budget (Farmer et al.,
2018; Harris et al., 2017; King et al., 2015; National Academy of Science, 2017; New et al.,
2014; Southall et al., 2007; Villegas-Amtmann et al., 2015).

Temporary Threshold Shift
TTS is one form of Level B harassment that marine mammals may incur through
exposure to the specified activities and, as described earlier, the takes by Level B harassment
may represent takes in the form of direct behavioral disturbance, TTS, or both. As discussed in
the “Potential Effects of Specified Activities on Marine Mammals and their Habitat” section of
the proposed rule, in general, TTS can last from a few minutes to days, be of varying degree, and
occur across different frequency bandwidths, all of which determine the severity of the impacts
on the affected individual, which can range from minor to more severe. Impact and vibratory pile
driving, drilling, and UXO/MEC detonation are broadband noise sources but generate sounds in
the lower frequency ranges (with most of the energy below 1-2 kHz, but with a small amount
energy ranging up to 20 kHz); therefore, in general and all else being equal, we would anticipate
the potential for TTS is higher in low-frequency cetaceans (i.e., mysticetes) than other marine
mammal hearing groups, and would be more likely to occur in frequency bands in which they
communicate. However, we would not expect the TTS to span the entire communication or
hearing range of any species given that the frequencies produced by these activities do not span
entire hearing ranges for any particular species. Additionally, though the frequency range of TTS
that marine mammals might sustain would overlap with some of the frequency ranges of their
vocalizations, the frequency range of TTS from the Project’s pile driving, drilling, and
UXO/MEC detonation activities would not typically span the entire frequency range of one
vocalization type, much less span all types of vocalizations or other critical auditory cues for any
given species. The required mitigation measures further reduce the potential for TTS in
mysticetes.
Generally, both the degree of TTS and the duration of TTS would be greater if the marine
mammal is exposed to a higher level of energy (which would occur when the peak dB level is
higher or the duration is longer). The threshold for the onset of TTS was discussed previously
(refer back to Estimated Take section). However, source level alone is not a predictor of TTS.

An animal would have to approach closer to the source or remain in the vicinity of the sound
source appreciably longer to increase the received SEL, which would be difficult considering the
required mitigation and the nominal speed of the receiving animal relative to the stationary
sources such as impact pile driving. The recovery time is also of importance when considering
the potential impacts from TTS. In TTS laboratory studies (as discussed in the “Potential Effects
of the Specified Activities on Marine Mammals and their Habitat” section of the proposed rule),
some using exposures of almost an hour in duration or up to 217 SEL, almost all individuals
recovered within 1 day or less (often in minutes) and we note that while the pile-driving
activities last for hours a day, it is unlikely that most marine mammals would stay in the close
vicinity of the source long enough to incur more severe TTS. UXO/MEC detonation also has the
potential to result in TTS. However, given the duration of exposure is extremely short
(milliseconds), the degree of TTS (i.e., the amount of dB shift) is expected to be small and TTS
duration is expected to be short (minutes to hours). Overall, given the small number of times that
any individual might incur TTS, the low degree of TTS and the short anticipated duration, and
the unlikely scenario that any TTS overlapped the entirety of a critical hearing range, it is
unlikely that TTS (of the nature expected to result from the Project's activities) would result in
behavioral changes or other impacts that would impact any individual's (of any hearing
sensitivity) reproduction or survival.
Permanent Threshold Shift
NMFS may authorize a very small amount of take by PTS to some marine mammal
individuals. The numbers of annual takes by Level A harassment that may be authorized are
relatively low for all marine mammal stocks and species (table 35). The only activity incidental
to which we anticipate PTS may occur is from exposure to impact pile driving and UXO/MEC
detonations, which produce sounds that are both impulsive and primarily concentrated in the
lower frequency ranges (below 1 kHz) (David, 2006; Krumpel et al., 2021).

There are no PTS data on cetaceans and only one recorded instance of PTS being induced
in older harbor seals (Reichmuth et al., 2019). However, available TTS data of mid-frequency
hearing specialists exposed to mid- or high-frequency sounds (Southall et al., 2007; NMFS,
2018; Southall et al., 2019) suggest that most threshold shifts occur in the frequency range of the
source up to one octave higher than the source. We would anticipate a similar result for PTS.
Further, no more than a small degree of PTS is expected to be associated with any of the incurred
Level A harassment, given that it is unlikely that animals would stay in the close vicinity of a
source for a duration long enough to produce more than a small degree of PTS. Given
UXO/MEC detonation is instantaneous, the potential for PTS is not a function of duration.
NMFS recognizes the distances to PTS thresholds may be large for certain species (e.g., over 4
km based on the largest charge weights; table 37); however, there would be multiple
vessels/platforms equipped with PSOs as well as activity PAM requirements to observe and
acoustically detect marine mammals. A marine mammal within the PTS zone would trigger a
delay to detonation; thereby minimizing potential for PTS for all marine mammal species and
ensuring that any PTS that does occur is of a relatively low degree
PTS would consist of minor degradation of hearing capabilities occurring predominantly
at frequencies one-half to one octave above the frequency of the energy produced by pile driving
or instantaneous UXO/MEC detonations (i.e., the low-frequency region below 2 kHz) (Cody and
Johnstone, 1981; McFadden, 1986; Finneran, 2015), not severe hearing impairment. If hearing
impairment occurs from either impact pile driving or UXO/MEC detonation, it is most likely that
the affected animal would lose a few decibels in its hearing sensitivity, which in most cases is
not likely to meaningfully affect its ability to forage and communicate with conspecifics.
Avangrid estimates 10 UXO/MECs may be detonated and the exposure analysis assumes the
worst-case scenario that all of the UXO/MECs found would consist of the largest charge weight
of UXO/MEC (E12; 454 kg). However, it is highly unlikely that all charges would be this
maximum size; thus, the amount of Level A harassment that may occur incidental to the

detonation of the UXO/MECs would likely be less than what is estimated here. In addition,
during impact pile driving, given sufficient notice through use of soft-start prior to
implementation of full hammer energy during impact pile driving, marine mammals are expected
to move away from a sound source that is annoying prior to it resulting in severe PTS.
Auditory Masking or Communication Impairment
The ultimate potential impacts of masking on an individual are similar to those discussed
for TTS (e.g., decreased ability to communicate, forage effectively, or detect predators), but an
important difference is that masking only occurs during the time of the signal, versus TTS, which
continues beyond the duration of the signal. Masking may also result from the sum of exposure
to multiple signals, none of which might individually cause TTS. Fundamentally, masking is
referred to as a chronic effect because one of the key potential harmful components of masking is
its duration—the fact that an animal would have reduced ability to hear or interpret critical cues
becomes much more likely to cause a problem the longer it is occurring. Inherent in the concept
of masking is the fact that the potential for the effect is only present during the times that the
animal and the source are in close enough proximity for the effect to occur (and further, this time
period would need to coincide with a time that the animal was utilizing sounds at the masked
frequency).
As our analysis has indicated, for this project we expect that impact pile driving
foundations have the greatest potential to mask marine mammal signals, and this pile driving
may occur for several, albeit intermittent, hours per day, for multiple days per year. Masking is
fundamentally more of a concern at lower frequencies (which are pile-driving dominant
frequencies) because low frequency signals propagate significantly further than higher
frequencies. Low frequency signals are also more likely to overlap with the narrower low
frequency calls of mysticetes, many non-communication cues related to fish and invertebrate
prey, and geologic sounds that inform navigation. However, the area in which masking would
occur for all marine mammal species and stocks (e.g., predominantly in the vicinity of the

foundation pile being driven) is small relative to the extent of habitat used by each species and
stock.
In summary, the nature of the specified activities, paired with habitat use patterns by
marine mammals, makes it unlikely that the level of masking that could occur would have the
potential to affect reproductive success or survival.
Impacts on Habitat and Prey
Construction activities (i.e., foundation installation and UXO/MEC detonation) may
result in fish and invertebrate mortality or injury very close to the source, and all of the specified
activities may cause some fish to leave the area of disturbance. It is anticipated that any mortality
or injury would be limited to a very small subset of available prey and the implementation of
mitigation measures such as the use of a NAS during foundation installation and UXO/MEC
detonations would further limit the degree of impact. Behavioral changes in prey in response to
construction activities could temporarily impact marine mammals' foraging opportunities in a
limited portion of the foraging range but, because of the relatively small area of the habitat that
may be affected at any given time (e.g., around a pile being driven), the impacts to marine
mammal habitat are not expected to cause significant or long-term negative consequences.
Cable presence is not anticipated to impact marine mammal habitat as these would be
buried, and any electromagnetic fields emanating from the cables are not anticipated to result in
consequences that would impact marine mammals prey to the extent they would be unavailable
for consumption.
The presence of wind turbines within the Lease Area could have longer-term impacts on
marine mammal habitat, as the Project would result in the persistence of the structures within
marine mammal habitat for more than 30 years. The presence of an extensive number of
structures such as wind turbines are, in general, likely to result in local and broader
oceanographic effects in the marine environment, and may disrupt dense aggregations and
distribution of marine mammal zooplankton prey through altering the strength of tidal currents

and associated fronts, changes in stratification, primary production, the degree of mixing, and
stratification in the water column (Chen et al., 2021; Johnson et al., 2021; Christiansen et al.,
2022; Dorrell et al., 2022). However, the scale of impacts is difficult to predict and may vary
from hundreds of meters for local individual turbine impacts (Schultze et al., 2020) to large-scale
changes stretching hundreds of kilometers (Christiansen et al., 2022).
As discussed in the “Potential Effects of the Specified Activities on Marine Mammals
and their Habitat” section of the proposed rule, the Project would consist of no more than 132
foundation positions (WTGs and ESPs) in the Lease Area, which will gradually become
operational following construction completion and by the end of this rule. While there are likely
to be oceanographic impacts from the presence of the Project, meaningful oceanographic impacts
relative to stratification and mixing that would significantly affect marine mammal habitat and
prey over large areas in key foraging habitats during the effective period of the regulations are
not anticipated. Although this area supports aggregations of zooplankton (i.e., baleen whale prey)
that could be impacted if long-term oceanographic changes occurred, prey densities are typically
significantly less in the Project Area than in known baleen whale foraging habitats to the east and
north (e.g., south of Nantucket and Martha's Vineyard, Great South Channel). For these reasons,
if oceanographic features are affected by the Project during the effective period of the
regulations, the impact on marine mammal habitat and their prey is likely to be comparatively
minor.
The New England Wind BiOp provided an evaluation of the presence and operation of
the Project on, among other species, listed marine mammals and their prey. Overall, the BiOp
concluded that impacts from loss of soft bottom habitat from the presence of turbines and
placement of scour protection as well as any beneficial reef effects, are expected to be so small
that they cannot be meaningfully measured, evaluated, or detected and are, therefore,
insignificant. The BiOp also concluded that while the presence and operation of the wind farm
may change the distribution of plankton with the wind farm, these changes are not expected to

affect the oceanographic forces transporting zooplankton into the area. Regional distribution of
plankton may vary from pre-wind facility conditions; however, given the lack of a known
bathymetric feature that aggregates zooplankton prey in the lease area and acknowledging the
information and uncertainty presented in the BiOp, the BiOp was not able to conclude that
adverse effects on North Atlantic right whale foraging success due to near-field effects are
reasonably certain to occur. Relative to far-field effects (tens of kilometers from the outermost
row of foundations in the New England Wind lease area), the BiOp does not anticipate disruption
to conditions that would aggregate prey in or outside the WFA that would have significant
effects on ESA listed species. This is due to the scale of the project and its location in the center
of the southern New England region and away from Nantucket Shoals and the tidal jet along the
edge of Nantucket Shoals that are thought to aggregate zooplankton prey in that region.
Therefore, the BiOp concluded that an overall reduction in biomass of plankton is not an
anticipated outcome of operating the Project. Thus, because broader changes in the biomass of
zooplankton are not anticipated, any higher trophic level impacts are also not anticipated. That is,
no effects to pelagic fish or benthic invertebrates that depend on plankton as forage food are
expected to occur. Zooplankton, fish, and invertebrates are all considered marine mammal prey
and, as fully described in the BiOp, measurable, detectable, or significant changes to marine
mammal prey abundance and distribution from wind farm operation are not anticipated.
Mitigation to Reduce Impact on All Species
This rule includes an extensive suite of mitigation measures designed to minimize
impacts on all marine mammals, with a focus on North Atlantic right whales. The Mitigation
section discusses the manner in which the required mitigation measures reduce the magnitude
and/or severity of the take of marine mammals, including the following. For installation of
foundation piles, 10 overarching mitigation measures are required, which are intended to reduce
both the number and intensity of marine mammal takes: (1) seasonal/time of day work
restrictions; (2) use of multiple PSOs to visually observe for marine mammals (with any

detection within specifically designated zones that would trigger a delay or shutdown); (3) use of
PAM to acoustically detect marine mammals, with a focus on detecting baleen whales (with any
detection within designated zones triggering delay or shutdown); (4) implementation of
clearance zones; (5) implementation of shutdown zones; (6) use of soft-start (impact pile driving
only); (7) use of noise attenuation technology; (8) maintaining situational awareness of marine
mammal presence through the requirement that any marine mammal sighting(s) by Avangrid
personnel must be reported to PSOs; (9) SFV monitoring; and (10) vessel strike avoidance
measures to reduce the risk of a collision with a marine mammal and vessel. For UXO/MEC
detonation, all the same measures as foundation installation are required except for soft-start and
shutdown zones; neither are possible as a detonation is an instantaneous event. Lastly, for HRG
surveys, we are requiring six measures: (1) measures specifically for Vessel Strike Avoidance;
(2) specific requirements during daytime and nighttime HRG surveys; (3) implementation of
clearance zones; (4) implementation of shutdown zones; (5) use of ramp-up of acoustic sources;
and (6) maintaining situational awareness of marine mammal presence through the requirement
that any marine mammal sighting(s) by Avangrid personnel must be reported to PSOs.
For activities with large harassment isopleths, Avangrid is committed to reducing the
noise levels generated to the lowest levels practicable and is required to ensure that they do not
exceed a noise footprint above that which was modeled, assuming a 10-dB attenuation. Use of a
soft-start during impact pile driving will allow animals to move away from (i.e., avoid) the sound
source prior to applying higher hammer energy levels needed to install the pile (i.e., Avangrid
will not use a hammer energy greater than necessary to install piles). Similarly, ramp-up during
HRG surveys would allow animals to move away and avoid the acoustic sources before they
reach their maximum energy level. For all activities, clearance zone and shutdown zone
implementation, which are required when marine mammals are within given distances associated
with certain impact thresholds for all activities, will reduce the magnitude and severity of marine
mammal take. Additionally, the use of multiple PSOs (e.g., WTG and ESP foundation

installation, UXO/MEC detonation, HRG surveys), PAM operators (for foundation installation
and UXO/MEC detonation), and maintaining awareness of marine mammal sightings reported in
the region during all specified activities will aid in detecting marine mammals that would trigger
the implementation of the mitigation measures. The reporting requirements including SFV
reporting (for foundation installation and foundation operation), will assist NMFS in identifying
if impacts beyond those analyzed in this final rule are occurring, potentially leading to the need
to enact adaptive management measures in addition to or in place of the mitigation measures.
Mysticetes
Six mysticete species (comprising six stocks) of cetaceans (i.e., North Atlantic right
whale, blue whale, humpback whale, fin whale, sei whale, and minke whale) may be taken by
harassment. These species, to varying extents, utilize the specified geographical region,
including the Project Area, for the purposes of migration, foraging, and socializing. Mysticetes
are in the low-frequency hearing group.
Behavioral data on mysticete reactions to pile-driving noise are scant. Kraus et al. (2019)
predicted that the three main impacts of offshore wind farms on marine mammals would consist
of displacement, behavioral disruptions, and stress. Broadly, we can look to studies that have
focused on other noise sources such as seismic surveys and military training exercises, which
suggest that exposure to loud signals can result in avoidance of the sound source (or
displacement if the activity continues for a longer duration in a place where individuals would
otherwise have been staying, which is less likely for mysticetes in this area), disruption of
foraging activities (if they are occurring in the area), local masking around the source, associated
stress responses, impacts to prey, and TTS or PTS (in some cases).
Mysticetes encountered in the Project Area are expected to be migrating or foraging. The
extent to which an animal engages in these behaviors in the area is species-specific and varies
seasonally. Given that feeding Biologically Important Areas (BIAs) for the North Atlantic right
whale, humpback whale, fin whale, sei whale, and minke whale exist to the east and north of the

Project Area (LaBrecque et al., 2015; Van Parijs et al., 2015), many mysticetes are expected to
predominantly be migrating through the Project Area towards or from these feeding grounds.
While we acknowledged above that mortality, hearing impairment, or displacement of mysticete
prey species may result locally from impact pile driving and UXO/MEC detonations, given the
very short duration of and broad availability of prey species in the area and the availability of
alternative suitable foraging habitat for the mysticete species most likely to be affected, any
impacts on mysticete foraging is expected to be minor. Whales temporarily displaced from the
Project Area are expected to have sufficient remaining feeding habitat available to them and
would not be prevented from feeding in other areas within the biologically important feeding
habitats found further north. In addition, any displacement of whales or interruption of foraging
bouts would be expected to be relatively temporary in nature.
The potential for repeated exposures is dependent upon the residency time of whales with
migratory animals unlikely to be exposed on repeated occasions and animals remaining in the
area to be more likely exposed repeatedly. For mysticetes, where relatively low numbers of
species-specific take by Level B harassment are predicted (compared to the abundance of each
mysticete species or stock; see table 35) and movement patterns suggest that individuals would
not necessarily linger in a particular area for multiple days, each predicted take likely represents
an exposure of a different individual, with perhaps a subset of takes for a few species potentially
representing a few repeated of a limited number of individuals across multiple days. In other
words, the behavioral disturbance to any individual mysticete would, therefore, be expected to
mostly likely occur within a single day within a year, or potentially across a few days, and would
not be expected to impact reproduction or survival. In general, the duration of exposures would
not be continuous throughout any given day and pile driving would not occur on all consecutive
days within a given year due to weather delays or any number of logistical constraints Avangrid
has identified. Species-specific analysis regarding potential for repeated exposures and impacts is
provided below.

Fin, blue, minke, sei, and humpback whales are the only mysticete species for which PTS
is anticipated and may be authorized. As described previously, PTS for mysticetes from some
project activities may overlap frequencies used for communication, navigation, or detecting prey.
However, given the nature and duration of the activity, the mitigation measures, and likely
avoidance behavior, any PTS is expected to be of a small degree, would be limited to frequencies
where pile-driving noise is concentrated (i.e., only a small subset of their expected hearing
range) and would not be expected to impact reproductive success or survival.
North Atlantic Right Whale
North Atlantic right whales are listed as endangered under the ESA and as both a
depleted and strategic stock under the MMPA. As described in the “Potential Effects to Marine
Mammals and Their Habitat” section of the proposed rule, North Atlantic right whales are
threatened by a low population abundance, higher than average mortality rates, and lower than
average reproductive rates. Recent studies have reported individuals showing high stress levels
(e.g., Corkeron et al., 2017) and poor health, which has further implications on reproductive
success and calf survival (Christiansen et al., 2020; Stewart et al., 2021; Stewart et al., 2022). As
described below, a UME has been designated for North Atlantic right whales. Given this, the
status of the North Atlantic right whale population is of heightened concern and, therefore,
merits additional analysis and consideration. No Level A harassment, serious injury, or mortality
is anticipated or may be authorized for this species.
For North Atlantic right whales, this rule may authorize up to 126 takes, by Level B
harassment only, over the 5-year period, with a maximum annual allowable take of 60 (equating
to approximately 17.65 percent of the stock abundance, if each take were considered to be of a
different individual), with far lower numbers than that expected in the years without foundation
installation or UXO/MEC detonations (e.g., years when only HRG surveys would be occurring).
The Project Area is known as a migratory corridor for North Atlantic right whales and given the

nature of migratory behavior (e.g., continuous path), as well as the low number of total takes, we
anticipate that few, if any, of the instances of take would represent repeat takes of any individual.
The highest density of North Atlantic right whales in the Project Area occurs in the
winter (tables 7-9). The New York Bight, including the Project Area, may be a stopover site for
migrating North Atlantic right whales moving to or from southeastern calving grounds. As
described above, the Project Area represents part of an important migratory area for right whales.
Quintana-Rizzo et al. (2021) noted that southern New England, northeast of the Project Area,
may be a stopover site for migrating right whales moving to or from southeastern calving
grounds. The North Atlantic right whales observed during the study period were primarily
concentrated in the northeastern and southeastern sections of the MA WEA during the summer
(June–August) and winter (December–February). North Atlantic right whale distribution did
shift to the west into the Rhode Island/Massachusetts Wind Energy Area (RI/MA WEA) in the
spring (March–May). Overall, the Project Area contains habitat less frequently utilized by North
Atlantic right whales than the more northerly southern New England region.
In general, North Atlantic right whales in the Project Area are expected to be engaging in
migratory behavior. Given the species' migratory behavior in the Project Area, we anticipate
individual whales would be typically migrating through the area during most months when
foundation installation and UXO/MEC detonation would occur, given the strict seasonal
restrictions on foundation installation and UXO/MEC detonations from January through April,
rather than lingering in the Project Area for extended periods of time. Other work that involves
either much smaller harassment zones (e.g., HRG surveys) or is limited in amount (e.g.,
UXO/MEC detonation) may also occur during periods when North Atlantic right whales are
using the habitat for migration. Therefore, it is likely that many of the takes would occur to
separate individual whales, each disturbed on no more than 1 day. It is important to note that the
activities occurring from December through May that may impact North Atlantic right whales
would be primarily HRG surveys, which would not result in very high received levels, if any at

all, because of both the lower sources and the mitigation and monitoring measures that avoid or
minimize impacts. Across all years, while it is possible an animal could have been exposed
during a previous year, the low amount of take that may be authorized during the 5-year period
of the rule makes this scenario possible but unlikely. However, if an individual were to be
exposed during a subsequent year, the impact of that exposure is likely independent of the
previous exposure and would cause no additive effect given the duration between exposures.
As described in the Description of Marine Mammals in the Geographic Area section
of the proposed rule, North Atlantic right whales are presently experiencing an ongoing UME
(beginning in June 2017). Preliminary findings support human interactions, specifically vessel
strikes and entanglements, as the cause of death for the majority of North Atlantic right whales.
Given the current status of the North Atlantic right whale, the loss of even one individual could
significantly impact the population. No mortality, serious injury, or injury of North Atlantic right
whales as a result of the Project is expected or may be authorized. Any disturbance to North
Atlantic right whales due to the specified activities is expected to result in temporary avoidance
of the immediate area of construction. As no injury, serious injury, or mortality is expected or
may be authorized, and Level B harassment of North Atlantic right whales will be reduced to the
level of least-practicable adverse impact through use of mitigation measures, the number of takes
of North Atlantic right whales that may be authorized would not exacerbate or compound the
effects of the ongoing UME.
As described in the general Mysticetes section above, foundation installation is likely to
result in the highest amount of annual take and is of greatest concern given loud source levels.
This activity would likely be limited to up to 113 days over a maximum of 3 years, during times
when, based on the best available scientific data, North Atlantic right whales are less frequently
encountered due to their migratory behavior. The potential types, severity, and magnitude of
impacts are also anticipated to mirror that described in the general Mysticetes section above,
including avoidance (the most likely outcome), changes in foraging or vocalization behavior,

masking, a small amount of TTS, and temporary physiological impacts (e.g., change in
respiration, change in heart rate). Importantly, the effects of the activities are expected to be
sufficiently low-level and localized to specific areas as to not meaningfully impact important
behaviors such as migratory behavior of North Atlantic right whales. These takes are expected to
result in temporary behavioral reactions, such as slight displacement (but not abandonment) of
migratory habitat or temporary cessation of feeding. Further, given these exposures are generally
expected to occur to different individual right whales migrating through (i.e., many individuals
would not be impacted on more than 1 day in a year), and with some subset potentially being
exposed on no more than a few days within the year, they are unlikely to result in energetic
consequences that could affect reproduction or survival of any individuals.
Overall, NMFS expects that any behavioral harassment of North Atlantic right whales
incidental to the specified activities would not result in changes to their migration patterns or
foraging success, as only temporary avoidance of an area during construction is expected to
occur. As described previously, North Atlantic right whales migrating through the Project Area
are not expected to remain in this habitat for extensive durations, and any temporarily displaced
animals would be able to return to or continue to travel through and forage in these areas once
activities have ceased.
Although acoustic masking may occur in the vicinity of the foundation installation
activities, based on the acoustic characteristics of noise associated with pile driving and drilling
(e.g., frequency spectra, short duration of exposure) and construction surveys (e.g., intermittent
signals), NMFS expects masking effects to be minimal (e.g., effects of foundation installation)
and for HRG surveys, would not appreciably occur given the directionality of the signals for the
HRG survey equipment planned for use and the brief period for when an individual mammal
would likely be exposed. In addition, masking would likely only occur during the period of time
that a North Atlantic right whale is in the relatively close vicinity of pile driving, which is
expected to be intermittent within a day, and confined to the months in which North Atlantic

right whales are at lower densities and primarily moving through the area, anticipated mitigation
effectiveness, and likely avoidance behaviors. TTS is another possible form of Level B
harassment that could result in brief periods of slightly reduced hearing sensitivity, affecting
behavioral patterns by making it more difficult to hear or interpret acoustic cues within the
frequency range (and slightly above) of sound produced during impact pile driving. However,
any TTS would likely be of low amount, limited duration, and limited to frequencies where most
construction noise is centered (i.e., below 2 kHz). NMFS expects that right whale hearing
sensitivity would return to pre-exposure levels shortly after migrating through the area or moving
away from the sound source.
As described in the “Potential Effects to Marine Mammals and Their Habitat” section of
the proposed rule, the distance of the receiver to the source influences the severity of response,
with greater distances typically eliciting less severe responses. NMFS recognizes North Atlantic
right whales migrating could be pregnant females (in the fall) and mothers with older calves (in
the spring) and that these animals may slightly alter their migration course in response to any
foundation pile driving. However, as described in the “Potential Effects to Marine Mammals and
Their Habitat” section of the proposed rule, we anticipate that course diversion would be of small
magnitude. Hence, while some avoidance of the pile-driving activities may occur, we anticipate
any avoidance behavior of migratory North Atlantic right whales would be similar to that of gray
whales (Tyack et al., 1983), on the order of hundreds of meters up to 1 to 2 km. This diversion
from a migratory path otherwise uninterrupted by the Project’s activities is not expected to result
in meaningful energetic costs that would impact annual rates of recruitment of survival. NMFS
expects that North Atlantic right whales would be able to avoid areas during periods of active
noise production while not being forced out of this portion of their habitat.
North Atlantic right whale presence in the Project Area is year-round. However,
abundance during summer months is lower compared to the winter months, with spring and fall
serving as “shoulder seasons” wherein abundance waxes (fall) or wanes (spring). Given this

year-round habitat usage, in recognition that where and when whales may actually occur during
project activities is unknown as it depends on the annual migratory behaviors, NMFS is requiring
a suite of mitigation measures designed to reduce impacts to North Atlantic right whales to the
maximum extent practicable. These mitigation measures (e.g., seasonal/daily work restrictions,
vessel separation distances, reduced vessel speed) would not only avoid the likelihood of vessel
strikes but also would minimize the severity of behavioral disruptions by minimizing impacts
(e.g., through sound reduction using attenuation systems and reduced temporal overlap of project
activities and North Atlantic right whales). This would further ensure that the number of takes by
Level B harassment that are estimated to occur are not expected to affect reproductive success or
survivorship by detrimental impacts to energy intake or cow/calf interactions during migratory
transit. However, even in consideration of recent habitat-use and distribution shifts, Avangrid
would still be installing foundations when the presence of North Atlantic right whales is
expected to be lower.
As described in the Description of Marine Mammals in the Geographic Area section,
Avangrid would be constructed within the North Atlantic right whale migratory corridor BIA,
which represents areas and months within which a substantial portion of a species or population
is known to migrate. The area over which North Atlantic right whales may be harassed is
relatively small compared to the width of the migratory corridor. The width of the migratory
corridor in this area is approximately 300 km while the width of the Lease Area, at the longest
point, is approximately 50 km and the width of the ensonified area with the largest distance to
Level B harassment for North Atlantic right whale during foundation installation (vibratory pile
driving) is approximately 105 km from the westernmost point to easternmost point. North
Atlantic right whales may be displaced from their normal path and preferred habitat in the
immediate activity area primarily from pile-driving activities; however, we do not anticipate
displacement to be of high magnitude (e.g., beyond a few kilometers). Thereby, any associated
bio-energetic expenditure is anticipated to be small. There are no known North Atlantic right

whale feeding, breeding, or calving areas within the Project Area. Prey species are mobile (e.g.,
calanoid copepods can initiate rapid and directed escape responses) and are broadly distributed
throughout the Project Area (noting again that North Atlantic right whale prey is not particularly
concentrated in the Project Area relative to nearby habitats). Therefore, any impacts to prey that
may occur are also unlikely to impact North Atlantic right whales.
The most significant measure to minimize impacts to individual North Atlantic right
whales during monopile installations is the seasonal moratorium on foundation installation for all
piles from January 1 through April 30 (with no impact pile driving or drilling scheduled in
December and no vibratory pile driving in May and December, though pile driving may occur in
December if it is unavoidable and only upon approval from NMFS) when North Atlantic right
whale abundance in the Project Area is expected to be highest. UXO/MEC detonations would
also be restricted from December through May. NMFS also expects this measure to greatly
reduce the potential for mother/calf pairs to be exposed to foundation installation noise above the
Level B harassment threshold during their annual spring migration through the Project Area from
calving grounds to primary foraging grounds (e.g., Cape Cod Bay). NMFS expects that the
severity of any take of North Atlantic right whales would be reduced due to the additional
mitigation measures that would ensure that any exposures above the Level B harassment
threshold would result in only short-term effects to individuals exposed.
Foundation installation and UXO/MEC detonation may only begin in the absence of
North Atlantic right whales, as determined by visual and PAM. If foundation installation or
UXO/MEC detonation has commenced, NMFS anticipates North Atlantic right whales would
avoid the area, utilizing nearby waters to carry on pre-exposure behaviors. However, foundation
installation must be shut down if a North Atlantic right whale is sighted at any distance, unless a
shutdown is not feasible due to risk of injury or loss of life. Shutdown may occur anywhere if
North Atlantic right whales are seen within or beyond the Level B harassment zone, further
minimizing the duration and intensity of exposure. NMFS anticipates that if North Atlantic right

whales go undetected and are exposed to foundation installation or UXO/MEC detonation noise,
it is unlikely a North Atlantic right whale would approach the source location to the degree that
they would purposely expose themselves to very high noise levels. These measures are designed
to avoid PTS and also reduce the severity of Level B harassment, including the potential for
TTS. While some TTS could occur, given the planned mitigation measures (e.g., delay pile
driving upon a sighting or acoustic detection and shutting down upon a sighting or acoustic
detection), the potential for TTS to occur is low.
The clearance and shutdown measures are most effective when detection efficiency is
maximized, as the measures are triggered by a visual or acoustic detection. To maximize
detection efficiency, NMFS requires the combination of PAM and visual observers. NMFS is
requiring communication protocols with other project vessels, and other heightened awareness
efforts (e.g., daily monitoring of North Atlantic right whale sighting databases) such that as a
North Atlantic right whale approaches the source, and thereby could be exposed to higher noise
energy levels, PSO detection efficacy would increase, the whale would be detected, and a delay
to commencing foundation installation or shutdown (if feasible) would occur. In addition, the
implementation of a soft-start for impact pile driving would provide an opportunity for whales to
move away from the source if they are undetected, reducing their received levels. Further,
Avangrid will not install pile foundations simultaneously. North Atlantic right whales would,
therefore, not be exposed to concurrent impact pile driving on any given day and the area
ensonified at any given time would be limited. The UXO/MEC detonations mitigation measures
described above would further reduce the potential to be exposed to high received levels.
For HRG surveys, the maximum distance to the Level B harassment threshold is 178 m.
The estimated take, by Level B harassment only, associated with HRG surveys is to account for
any North Atlantic right whale sightings PSOs may miss when HRG acoustic sources are active.
However, because of the short maximum distance to the Level B harassment isopleth (178 m),
the requirement that vessels maintain a distance of 500 m from any North Atlantic right whales,

the fact whales are unlikely to remain in close proximity to an HRG survey vessel for any length
of time, and that the acoustic source would be shut down if a North Atlantic right whale is
observed within 500 m of the source, any exposure to noise levels above the harassment
threshold (if any) would be very brief. To further minimize exposures, ramp-up of sub-bottom
profilers must be delayed during the clearance period if PSOs detect a North Atlantic right
whale, or any other ESA-listed species, within 500 m of the acoustic source. With
implementation of the mitigation requirements, take by Level A harassment is unlikely and,
therefore, NMFS would not plan to authorize. Potential impacts associated with Level B
harassment would include low-level, temporary behavioral modifications, most likely in the form
of avoidance behavior. Given the high level of precautions taken to minimize both the amount
and intensity of Level B harassment on North Atlantic right whales, it is unlikely that the
anticipated low-level exposures would lead to reduced reproductive success or survival.
As described above, no serious injury or mortality, or Level A harassment, of North
Atlantic right whale is anticipated or may be authorized. Extensive North Atlantic right whalespecific mitigation measures beyond the robust suite required for all species are expected to
further minimize the amount and severity of Level B harassment. Given the documented habitat
use within the area, the majority of the individuals predicted taken (i.e., no more than 126
instances of take, by Level B harassment, over the course of the 5-year rule, with an annual
maximum of no more than 60 takes) would be impacted on only 1, or maybe 2, days in a year,
and any impacts to North Atlantic right whales are expected to be in the form of lower-level
behavioral disturbance. Given the magnitude and severity of the impacts discussed above, and in
consideration of the required mitigation and other information presented, the specified activities
are not expected to result in impacts on the reproduction or survival of any individuals, much
less affect annual rates of recruitment or survival. For these reasons, we have determined that the
take, by Level B harassment only, anticipated and that may be authorized would have a
negligible impact on the North Atlantic right whale.

Blue Whale
The blue whale, including the Western North Atlantic stock, is listed as Endangered
under the ESA, and as both Depleted and Strategic under the MMPA. There are no known areas
of specific biological importance in or around the project area, nor are there any UMEs. The
actual abundance of the stock is likely significantly greater than what is reflected in each SAR
because, as noted in the SARs, the most recent population estimates are primarily based on
surveys conducted in U.S. waters and the stock’s range extends well beyond the U.S. exclusive
economic zone (EEZ). No serious injury or mortality is anticipated or may be authorized for this
species.
The rule would allow for the authorization of up to 6 takes, by harassment only, over the
5-year period. The maximum annual allowable take by Level A harassment and Level B
harassment, would be 1 and 2, respectively (combined, this annual take (n= 3) equates to
approximately 0.75 percent of the stock abundance, if each take were considered to be of a
different individual), with far lower numbers than that expected in the years without foundation
installation (e.g., years when only HR surveys would be occurring). Based on the migratory
nature of blue whales and the fact that there are neither feeding nor reproductive areas
documented in or near the project area, and in consideration of the very low number of predicted
annual takes, it is unlikely that the predicted instances of takes would represent repeat takes of
any individual — in other words, each take likely represents one whale exposed on one day
within a year.
With respect to the severity of those individual takes by behavioral Level B harassment,
we would anticipate impacts to be limited to low-level, temporary behavioral responses with
avoidance and potential masking impacts in the vicinity of the turbine installation to be the most
likely type of response. Any potential PTS or TTS would be concentrated at half or one octave
above the frequency band of pile driving noise (most sound is below 2 kHz) which does not
include the full predicted hearing range of sei whales. Any hearing ability temporarily impaired

from TTS is anticipated to return to pre-exposure conditions shortly after the exposures cease
(e.g., if the animal moves away or the source stops). Any avoidance of the project area due to the
Project’s activities would be expected to be temporary.
Given the magnitude and severity of the impacts discussed above, and in consideration of
the proposed mitigation and other information presented, the specified activities are not expected
to result in impacts on the reproduction or survival of any individuals, much less affect annual
rates of recruitment or survival. For these reasons, we have determined that the take (by
harassment only) anticipated and that may be authorized would have a negligible impact on the
Western North Atlantic stock of blue whales.
Fin Whale
The fin whale is listed as Endangered under the ESA, and the western North Atlantic
stock is considered both Depleted and Strategic under the MMPA. No UME has been designated
for this species or stock. No serious injury or mortality is anticipated or may be authorized for
this species. Fin whales are present in the waters off of Massachusetts year-round and are one of
the most frequently observed large whales and cetaceans in continental shelf waters, principally
from Cape Hatteras in the Mid-Atlantic northward to Nova Scotia, Canada (Sergeant, 1977;
Sutcliffe and Brodie, 1977; Cetacean and Turtle Assessment Program (CETAP), 1982; Hain et
al., 1992; Geo-Marine, 2010; BOEM, 2012; Edwards et al., 2015; Hayes et al., 2022).
The rule would allow for the authorization of up to 421 takes, by harassment only, over
the 5-year period. The maximum annual allowable take by Level A harassment and Level B
harassment, would be 21 and 201, respectively. Combined, this annual take (n=222) equates to
approximately 3.26 percent of the stock abundance, if each take were considered to be of a
different individual, with far lower numbers than that expected in the years without foundation
installation (e.g., years when only HRG surveys would be occurring). Given the project overlaps
a small portion of a fin whale feeding BIA (2,933 km2) in the months the project will occur and

that southern New England is generally considered a feeding area, it is likely that some subset of
the individual whales exposed could be taken several times annually.
Level B harassment is expected to be in the form of behavioral disturbance, primarily
resulting in avoidance of the Project Area where foundation installation is occurring, and some
low-level TTS and masking that may limit the detection of acoustic cues for relatively brief
periods of time. Any potential PTS would be minor (i.e., limited to a few dB) and any TTS
would be of short duration and concentrated at half or one octave above the frequency band of
pile-driving noise with most sound below 2 kHz, which does not include the full predicted
hearing range of fin whales.
Fin whales are present in the waters off of New England year-round and are one of the
most frequently observed large whales and cetaceans in continental shelf waters, principally
from Cape Hatteras, North Carolina in the Mid-Atlantic northward to Nova Scotia, Canada
(Sergeant, 1977; Sutcliffe and Brodie, 1977; CETAP, 1982; Hain et al., 1992; Geo-Marine,
2010; BOEM 2012; Edwards et al., 2015; Hayes et al., 2022). In the Project Area, fin whales
densities are highest in the winter and summer months (Roberts et al., 2023) though detections
do occur in spring and fall (Watkins et al., 1987; Clark and Gagnon, 2002; Geo-Marine, 2010;
Morano et al., 2012). However, fin whales feed more extensively in waters in the Great South
Channel north to the Gulf Maine into the Gulf of St. Lawrence, areas north and east of the
Project Area (89 FR 5495, January 29, 2024).
As described previously in the proposed rule, the project area slightly overlaps a small fin
whale feeding BIA that is active from March to October. Foundation installations and
UXO/MEC detonations have seasonal work restrictions such that the temporal overlap between
these project activities and the active BIA timeframe would exclude the months of March or
April. We anticipate that if foraging is occurring in the Project Area and foraging whales are
exposed to noise levels of sufficient strength, they would avoid the Project Area and move into
the remaining area of the feeding BIA that would be unaffected to continue foraging without

substantial energy expenditure or, depending on the time of year, travel to the larger year-round
feeding BIA. Given the availability of other nearby feeding habitat, any impacts from any of the
planned activities to feeding activities are not anticipated to have significant impacts on fin
whale energetics or fitness.
Given the magnitude and severity of the impacts discussed above, including no more than
421 takes by harassment only over the course of the 5-year rule, and a maximum annual
allowable take by Level A harassment and Level B harassment, of 21 and 201, respectively, and
in consideration of the required mitigation and other information presented, the specified
activities are not expected to result in impacts on the reproduction or survival of any individuals,
much less affect annual rates of recruitment or survival. For these reasons, we have determined
that the take by harassment anticipated and that may be authorized will have a negligible impact
on the western North Atlantic stock of fin whales.
Humpback Whale
The West Indies DPS of humpback whales is not listed as threatened or endangered under
the ESA. However, as described in the Description of Marine Mammals in the Geographic
Area, humpback whales along the Atlantic Coast have been experiencing an active UME as
elevated humpback whale mortalities have occurred along the Atlantic coast from Maine through
Florida since January 2016. Of the cases examined, approximately 40 percent had evidence of
human interaction (i.e., vessel strike or entanglement). Despite the UME, the relevant population
of humpback whales (the West Indies breeding population, or DPS of which the Gulf of Maine
stock is a part) remains stable at approximately 12,000 individuals.
The rule would allow for the authorization of up to 301 takes by Level B harassment only
over the 5-year period. No take by Level A harassment may be authorized. The maximum annual
allowable take by Level A harassment and Level B harassment would be 18 and 134,
respectively (this maximum annual take (n=152) equates to approximately 10.89 percent of the
stock abundance, if each take were considered to be of a different individual), with far lower

numbers than that expected in the years without foundation installation (e.g., years when only
HRG surveys would be occurring). Among the activities analyzed, foundation installation is
likely to result in the highest amount of Level A harassment and Level B harassment annual take
(i.e., 17 and 126, respectively) of humpback whales.
A recent study examining humpback whale occurrence in the New York Bight area has
shown that humpback whales exhibit extended occupancy (mean 37.6 days) in the Bight area and
were likely to return from one year to the next (mean 31.3 percent). Whales were also seen at a
variety of other sites in the New York Bight within the same year, suggesting that they may
occupy this broader area throughout the feeding season. The majority of whales were seen during
summer (July–September, 62.5 percent), followed by autumn (October–December, 23.5
percent), and spring (April–June, 13.9 percent) (Brown et al., 2022). These data suggest that the
0 and 63 maximum annual instances of predicted takes by Level A harassment and Level B
harassment, respectively, could consist of individuals exposed to noise levels above the
harassment thresholds once during migration through the Project Area and/or individuals
exposed on multiple days if they are utilizing the area as foraging habitat. The Lease Area, which
is 321 km2, comprises only a minor portion of the New York Bight area (43,388 km2), and a few
repeated takes of the same individuals would be unlikely to meaningfully impact the energetics
of any individuals given the availability of favorable foraging habitat across the Bight.
For all the reasons described in the Mysticetes section above, we anticipate any potential
PTS and TTS would be concentrated at one half or one octave above the frequency band of piledriving noise (most sound is below 2 kHz), which does not include the full predicted hearing
range of baleen whales. If TTS is incurred, hearing sensitivity would likely return to preexposure levels relatively shortly after exposure ends. Any masking or physiological responses
would also be of low magnitude and severity for reasons described above.
Given the magnitude and severity of the impacts discussed above, including no more than
301 takes over the course of the 5-year rule, and a maximum annual allowable take by Level A

harassment and Level B harassment of 18 and 134, respectively, and in consideration of the
required mitigation measures and other information presented, the specified activities are not
expected to result in impacts on the reproduction or survival of any individuals, much less affect
annual rates of recruitment or survival. For these reasons, we have determined that the take by
harassment anticipated and may be authorized will have a negligible impact on the Gulf of
Maine stock of humpback whales.
Minke Whale
Minke whales are not listed under the ESA, and the Canadian East Coast stock is neither
considered depleted nor strategic under the MMPA. There are no known areas of specific
biological importance in or adjacent to the Project Area. As described in the Description of
Marine Mammals in the Geographic Area section, a UME has been designated for this species
but is pending closure. No serious injury or mortality is anticipated or authorized for this species.
The rule would allow for the authorization of up to 1,193 takes, by harassment only, over
the 5-year period. The maximum annual allowable take by Level A harassment and Level B
harassment would be 90 and 508, respectively (combined, this annual take (n=598) equates to
approximately 2.72 percent of the stock abundance, if each take were considered to be of a
different individual), with far lower numbers than that expected in the years without foundation
installation (e.g., years when only HRG surveys would be occurring).
Minke whales are common offshore the U.S. Eastern Seaboard with a strong seasonal
component in the continental shelf and in deeper, off-shelf waters (CETAP, 1982; Hayes et al.,
2022). In the Project Area, minke whales are predominantly migratory and their known feeding
areas are to the north, including a feeding BIA in the southwestern Gulf of Maine and George's
Bank. Therefore, they would be more likely to be moving through the Project Area, with each
take representing a separate individual. However, it is possible that some subset of the individual
whales exposed could be taken up to a few times annually.

As described in the Description of Marine Mammals in the Geographic Area section,
there is a UME for Minke whales, along the Atlantic coast from Maine through South Carolina,
with highest number of deaths in Massachusetts, Maine, and New York, and preliminary findings
in several of the whales have shown evidence of human interactions or infectious diseases.
However, we note that the population abundance is greater than 21,000 and the take that may be
authorized through this action is not expected to exacerbate the UME in any way.
We anticipate the impacts of this harassment to follow those described in the general
Mysticetes section above. Any potential PTS would be minor (i.e., limited to a few dB) and any
TTS would be of short duration and concentrated at one half or one octave above the frequency
band of pile-driving noise (most sound is below 2 kHz), which does not include the full predicted
hearing range of minke whales. Level B harassment would be temporary, with primary impacts
being temporary displacement of the Project Area but not abandonment of any migratory or
foraging behavior.
Given the magnitude and severity of the impacts discussed above (including no more
than 1,193 takes of the course of the 5-year rule, and a maximum annual allowable take by Level
A harassment and Level B harassment, of 90 and 508, respectively), and in consideration of the
required mitigation and other information presented, the specified activities are not expected to
result in impacts on the reproduction or survival of any individuals, much less affect annual rates
of recruitment or survival. For these reasons, we have determined that the take by harassment
anticipated and that may be authorized will have a negligible impact on the Canadian Eastern
Coastal stock of minke whales.
Sei Whale
Sei whales are listed as Endangered under the ESA, and the Nova Scotia stock is
considered both depleted and strategic under the MMPA. There are no known areas of specific
biological importance in or adjacent to the Project Area and no UME has been designated for this

species or stock. No serious injury or mortality is anticipated or may be authorized for this
species.
The rule would allow for the authorization of up to 74 takes, by harassment only, over the
5-year period. The maximum annual allowable take by Level A harassment and Level B
harassment would be 4 and 31, respectively (combined, this annual take (n=35) equates to
approximately 0.56 percent of the stock abundance, if each take were considered to be of a
different individual). Similar to other mysticetes, we would anticipate the number of takes to
represent individuals taken only once or, in rare cases two or three times, as most whales in the
Project Area would be migrating. To a small degree, sei whales may forage in the Project Area,
although the currently identified foraging habitats (BIAs) are to the northeast of the area in
which the specified activities would occur (LaBrecque et al., 2015).
With respect to the severity of those individual takes by behavioral Level B harassment,
we would anticipate impacts to be limited to low-level, temporary behavioral responses with
avoidance and potential masking impacts in the vicinity of the turbine installation to be the most
likely type of response. Any potential PTS and TTS would likely be concentrated at half or one
octave above the frequency band of pile-driving noise (most sound is below 2 kHz), which does
not include the full predicted hearing range of sei whales. Moreover, any TTS would be of a
small degree. Any avoidance of the Project Area due to the Project’s activities would be
expected to be temporary.
Given the magnitude and severity of the impacts discussed above (including no more
than 74 takes of the course of the 5-year rule, and a maximum annual allowable take by Level A
harassment and Level B harassment of 4 and 31, respectively), and in consideration of the
required mitigation and other information presented, the specified activities are not expected to
result in impacts on the reproduction or survival of any individuals, much less affect annual rates
of recruitment or survival. For these reasons, we have determined that the take by harassment

anticipated and that may be authorized will have a negligible impact on the Nova Scotia stock of
sei whales.
Odontocetes
In this section, we include information that applies to all of the odontocete species and
stocks addressed below. Odontocetes include dolphins, porpoises, and all other whales
possessing teeth, and we further divide them into the following subsections: sperm whales, small
whales and dolphins, and harbor porpoises. These subsections include more specific information,
as well as conclusions, for each stock represented.
The takes that may be authorized for odontocetes are incidental to the specified activities.
No serious injury or mortality may be authorized. We anticipate that, given ranges of individuals
(i.e., that some individuals remain within a small area for some period of time), and nonmigratory nature of some odontocetes in general (especially as compared to mysticetes), a larger
subset of these takes are more likely to represent multiple exposures of some number of
individuals than is the case for mysticetes, though some takes may also represent one-time
exposures to an individual. Foundation installation is likely to disturb odontocetes to the greatest
extent, compared to UXO/MEC detonations and HRG surveys. While we do expect animals to
avoid the area during foundation installation and UXO/MEC detonations, their habitat range is
extensive compared to the area ensonified during these activities. In addition, UXO/MEC
detonations are instantaneous; therefore, any disturbance would be very limited in time.
As described earlier, Level B harassment may include direct disruptions in behavioral
patterns (e.g., avoidance, changes in vocalizations (from masking) or foraging), as well as those
associated with stress responses or TTS. Odontocetes are highly mobile species, and, similar to
mysticetes, NMFS expects any avoidance behavior to be limited to the area near the sound
source. Passive acoustic data show that odontocete foraging dives may be disrupted by exposure
to loud sounds (Madsen et al., 2006; Miller et al., 2009; see “Diving and Foraging” in the
proposed rule). However, as stated in the proposed rule, changes in dive behavior in response to

noise exposure can vary widely and the changes may be a result of exposure to a sound source or
a natural variation in behavior. As foraging behavior may be temporarily affected in the vicinity
of the sound source (e.g., reduced dive rates, temporary area avoidance), NMFS expects that
foraging efforts would shift to other nearby foraging areas away from the sound source but does
not expect this to occur for a long duration but be limited to when sound sources (e.g., pile
driving, near instantaneous UXO/MEC detonation) are active . We do not expect foraging to be
appreciably reduced from HRG surveys given the minor nature of disturbance associated with
the activity and evidence that some odontocete species do not appear disturbed at all from these
surveys (e.g., bow riding dolphins). While masking could also occur during foundation
installation (e.g., to vocalizations, echolocation; see “Vocalizations and Auditory Masking”
section in the proposed rule for a detailed discussion), it would only occur in the vicinity of and
during the duration of the activity, and would not generally occur in a frequency range that
overlaps most odontocete communication or any echolocation signals. The mitigation measures
(e.g., use of sound attenuation systems, implementation of clearance and shutdown zones) would
also minimize received levels such that the severity of any behavioral response would be
expected to be less than exposure to unmitigated noise exposure.
Any masking or TTS effects are anticipated to be of low severity. First, while the
frequency range of pile driving, the most impactful planned activity in terms of response
severity, falls within a portion of the frequency range of most odontocete vocalizations,
odontocete vocalizations span a much wider range than the low frequency construction activities
planned for the project. Also, as described above, recent studies suggest odontocetes have a
mechanism to self-mitigate the impacts of noise exposure (i.e., reduce hearing sensitivity), which
could potentially reduce TTS impacts. Any masking or TTS is anticipated to be limited and
would typically only interfere with communication within a portion of an odontocete’s range and
as discussed earlier, the effects would only be expected to be of a short duration and for TTS, a
relatively small degree.

Furthermore, odontocete echolocation occurs predominantly at frequencies significantly
higher than low frequency construction activities. Therefore, there is little likelihood that
threshold shift would interfere with feeding behaviors. For HRG surveys, the sources operate at
higher frequencies than foundation installation activities and UXO/MEC detonations. However,
sounds from these sources attenuate very quickly in the water column, as described above.
Therefore, any potential for PTS and TTS and masking is very limited. Further, odontocetes
(e.g., common dolphins, spotted dolphins, and bottlenose dolphins) have demonstrated an
affinity to bow-ride actively surveying HRG surveys. Therefore, the severity of any harassment,
if it does occur, is anticipated to be minimal based on the lack of avoidance previously
demonstrated by these species.
The waters off the coast of Massachusetts are used by several odontocete species.
However, none except the sperm whale are listed under the ESA, and there are no known
habitats of particular importance. In general, odontocete habitat ranges are far-reaching along the
Atlantic coast of the United States, and the waters off of Massachusetts, including the Project
Area, do not contain any particularly unique odontocete habitat features.
Sperm Whale
Sperm whales are listed as endangered under the ESA, and the North Atlantic stock is
considered both Depleted and Strategic under the MMPA. The North Atlantic stock spans the
East Coast out into oceanic waters well beyond the U.S. EEZ. Although listed as endangered, the
primary threat faced by the sperm whale across its range (i.e., commercial whaling) has been
eliminated. Current potential threats to the species globally include vessel strikes, entanglement
in fishing gear, anthropogenic noise, exposure to contaminants, climate change, and marine
debris. There is no currently reported trend for the stock and, although the species is listed as
endangered under the ESA, there are no current related issues or events associated with the status
of the stock that cause particular concern (e.g., no UMEs). There are no known areas of

biological importance (e.g., critical habitat or BIAs) in or near the Project Area. No mortality or
serious injury is anticipated or may be authorized for this species.
The rule would allow for the authorization of up to 2 takes by Level A harassment and
108 takes by Level B harassment (n=110), over the 5-year period. No serious injury or mortality
may be authorized. The maximum annual allowable take by Level A harassment would be 1 and
Level B harassment would be 57, which equates to approximately 0.98 percent of the stock
abundance, if each take were considered to be of a different individual, with lower numbers than
that expected in the years without foundation installation (e.g., years when only HRG surveys
would be occurring). Given sperm whale's preference for deeper waters, especially for feeding, it
is unlikely that individuals will remain in the Project Area for multiple days, and therefore, the
estimated takes likely represent exposures of different individuals on 1 day annually.
If sperm whales are present in the Project Area during any Project activities, they will
likely be only transient visitors and not engaging in any significant behaviors. Further, the
potential for TTS is low for reasons described in the general Odontocetes section, but if it does
occur, any hearing shift would be small and of a short duration. Because whales are not expected
to be foraging in the Project Area, neither direct behavioral disturbance nor TTS are not expected
to interfere with foraging behavior. The most likely impact would be avoidance of the ensonified
areas around the activities during the time that the activities are occurring.
Given the magnitude and severity of the impacts discussed above (i.e., no more than 2
takes by Level A harassment and 108 takes by Level B harassment, over the course of the 5-year
rule, and a maximum annual allowable take of 58), and in consideration of the required
mitigation and other information presented, the specified activities are not expected to result in
impacts on the reproduction or survival of any individuals, much less affect annual rates of
recruitment or survival. For these reasons, we have determined that the take by harassment
anticipated and that may be authorized will have a negligible impact on the North Atlantic stock
of sperm whales.

Dolphins and Small Whales (including delphinids)
The twenty-six species and stocks included in this group (which are indicated in table 2
in the Delphinidae, Ziphiidae, and Kogiidae families) are not listed under the ESA, however,
pantropical spotted dolphins and spinner dolphins are listed as Depleted under the MMPA and
Short-finned pilot whales are listed as Strategic under the MMPA. The remaining species are not
listed as depleted or strategic under the MMPA. There are no known areas of specific biological
importance in or around the project area for any of these species, nor has a UME been designated
for any. No serious injury or mortality is anticipated or may be authorized for these species.
The eighteen delphinid species with take that may be authorized for the Project are
Atlantic spotted dolphin, Atlantic white-sided dolphin, bottlenose dolphin, Clymene dolphin,
common dolphin, long-finned pilot whale, short-finned pilot whale, Risso’s dolphin, false killer
whale, Fraser's dolphin, killer whale, melon-headed whale, pantropical spotted dolphin, pygmy
killer whale, rough-toothed dolphin, spinner dolphin, striped dolphin, and white-beaked dolphin.
Many of these delphinid species are rare for the project area, with preferred habitat at
much deeper water depths or different water temperatures than what are found within the project
area. For instance, the Clymene dolphin, false killer whale, Fraser's dolphin, melon-headed
whale, pantropical spotted dolphin, pygmy killer whale, rough-toothed dolphin, and spinner
dolphin prefer tropical to subtropical waters but have, on occasion, been sighted in deep waters
at or beyond the continental shelf break in the New England area during the summer months
(Hayes et al., 2019; Hayes et al., 2020). Striped dolphins are found in warm-temperate to tropical
waters but prefer continental slope waters offshore to the Gulf Stream, when in the New England
area they have only been sighted at water depths deeper than 900 m (Hayes et al., 2020). Whitebeaked dolphins prefer colder waters and are found more northerly than the project area in the
western Gulf of Maine and around Cape Cod (Hayes et al., 2020). Killer whales, a rarity in the
New England area, prefer much deeper and colder waters than those in the New England area
(Waring et al., 2015).

For seventeen of the Delphinid species, the rule would allow for the authorization of up
to between 10 and 3,543 takes (depending on species), by harassment only, over the 5-year
period. The maximum annual allowable take for these species by Level A harassment and Level
B harassment, would range from 0 to 1 and 5 to 2,067, respectively, (combined, this annual take
(n= 5 to 2,068) equates to approximately 0.1 to 3.20 percent of the stock abundance, if each take
were considered to be of a different individual), with far lower numbers than that expected in the
years without foundation installation (e.g., years when only HR surveys would be occurring).
For common dolphins, the eighteenth of the delphinid species, the rule would allow for
the authorization of up to 46,761 takes, by harassment only, over the 5-year period. The
maximum annual allowable take by Level A harassment is 1 and by Level B harassment is
26,572 (combined, this annual take (n= 26,573) equates to approximately to 28.54 percent of the
stock abundance, if each take were considered to be of a different individual), with far lower
numbers than that expected in the years without foundation installation (e.g., years when only
HR surveys would be occurring). Given both the comparatively higher number of takes and the
higher number of takes relative to the stock abundance, as well as the residential tendencies of
this species, while some of the takes likely represent exposures of different individuals on 1 or 2
days a year, it is likely that some subset of the individuals exposed could be taken several times
annually. As described above for odontocetes broadly, given the comparatively higher number of
estimated takes for some species and the behavioral patterns of odontocetes, we anticipate that a
fair number of these instances of take in a day represent multiple exposures of a smaller number
of individuals, meaning the actual number of individuals taken is lower. Although some amount
of repeated exposure to some individuals is likely given the duration of activity planned for the
specified activities, the intensity of any Level B harassment combined with the availability of
alternate nearby foraging habitat suggests that the likely impacts would not impact the
reproduction or survival of any individuals.

For Atlantic white-sided dolphin and Bottlenose dolphin, given the relatively higher
number of takes and as compared to the abundance, while many of the takes likely represent
exposures of different individuals on one day a year, some subset of the individuals exposed
could be taken up to a few times annually. For the remaining Delphinids, given they are
considered rare or uncommon in the area, it is unlikely that individuals would remain in the
project area for multiple days, and therefore the estimated takes likely represent exposures of
different individuals on one day each annually.
The six Ziphiidae species with take that may be authorized for the Project are Cuvier's
beaked whale, Blainville's beaked whale, Gervais' beaked whale, Sowerby's beaked whale,
True's beaked whale, and Northern bottlenose whale. The two species of Kogiidae with take that
may be authorized for the Project are the dwarf sperm whale and pygmy sperm whale. These
species are rare for the project area and prefer habitat at much deeper water depths than what are
found within the project area. For instance, the beaked whales and Kogiidae species have been
sighted in deep waters at or beyond the continental shelf break in the New England area (Hayes
et al., 2020). The Northern bottlenose whales are extremely uncommon or rare in waters of the
U.S and are rarely in waters less than 2,000 m deep (Waring et al., 2015). For these eight
species, the rule would allow for the authorization of up to between 6 and 8 takes for each
species, by harassment only, over the 5-year period. The maximum annual allowable take for
these species by Level A harassment and Level B harassment, would range from 0 to 2 and 2 to
4, respectively (combined, this annual take (n= 3 to 4) equates to approximately <0.1 percent of
the stock abundance for each species, if each take were considered to be of a different
individual), with far lower numbers than that expected in the years without foundation
installation (e.g., years when only HR surveys would be occurring). Given this species is
considered rare in the area and prefers deeper waters, especially for feeding, it is unlikely that
individuals would remain in the project area for multiple days, and therefore the estimated takes
likely represent exposures of different individuals on one day each annually.

The number of takes, likely movement patterns of the affected species, and the intensity
of any Level A or B harassments, combined with the availability of alternate nearby foraging
habitat suggests that the likely impacts would not impact the fitness, reproduction or survival of
any individuals. Some species, such as the common dolphin, are gregarious in nature (i.e., travel
in large groups) with high densities in the project area, which results in a relatively higher
amount of take. While delphinids may be taken on several occasions, none of these species are
known to have small home ranges within the project area or known to be particularly sensitive to
anthropogenic noise. The potential for PTS in dolphins and small whales is very low and, if PTS
does occur, would occur to a limited number of individuals, be of small degree, and would be
limited to the frequency ranges of the activity which does not span across most of their hearing
range. Some TTS can also occur but, again, it would be limited to the frequency ranges of the
activity and any loss of hearing sensitivity is anticipated to return to pre-exposure conditions
shortly after the animals move away from the source or the source ceases.
Beaked whales are known to be particularly sensitive to anthropogenic noise (e.g.,
Southall et al., 2017; Clowewiak et al., 2017); however, the project area does not contain
primary beaked whale habitat and only two to three groups of beaked whales could be harassed
by Project activities. Further, beaked whales are deep diver foragers and the shallow-water
project area does not contain suitable beaked whale foraging habitat. Hence, no foraging impacts
are anticipated.
Given the magnitude and severity of the impacts discussed above, and in consideration of
the proposed mitigation and other information presented, the specified activities are not expected
to result in impacts on the reproduction or survival of any individuals, much less affect annual
rates of recruitment or survival. For these reasons, we have determined that the take (by
harassment only) that may be authorized would have a negligible impact on all of the species and
stocks addressed in this section.

Harbor Porpoise
Harbor porpoises are not listed as Threatened or Endangered under the ESA, and the Gulf
of Maine/Bay of Fundy stock is neither considered depleted or strategic under the MMPA. The
stock is found predominantly in northern United States coastal waters, at less than 150 m depth
and up into Canada's Bay of Fundy, between New Brunswick and Nova Scotia. Although the
population trend is not known, there are no current related issues or events associated with the
status of the stock that cause particular concern (e.g., no UMEs).
The rule would allow for the authorization of up to 2,468 takes, by harassment only, over
the 5-year period. The maximum annual allowable take by Level A harassment and Level B
harassment would be 67 and 1,119, respectively (combined, this annual take (n=1,186) equates
to approximately 1.38 percent of the stock abundance, if each take were considered to be of a
different individual), with far lower numbers than that expected in the years without foundation
installation (e.g., years when only HRG surveys would be occurring). Given the number of takes,
while many of the takes likely represent exposures of different individuals on 1 day a year, some
subset of the individuals exposed could be taken up to a few times annually. No serious injury or
mortality may be authorized.
Regarding the severity of takes by Level B harassment, because harbor porpoises are
particularly sensitive to noise, it is likely that a fair number of the responses could be of a
moderate nature, particularly to pile driving. In response to pile driving, harbor porpoises are
likely to avoid the area during construction, as previously demonstrated in Tougaard et al. (2009)
in Denmark, in Dahne et al. (2013) in Germany, and in Vallejo et al. (2017) in the United
Kingdom, although a study by Graham et al. (2019) may indicate that the avoidance distance
could decrease over time. However, foundation installation is scheduled to occur off the coast of
Massachusetts and, given alternative foraging areas, any avoidance of the area by individuals is
not likely to impact the reproduction or survival of any individuals.

With respect to PTS and TTS, the effects on an individual are likely relatively low given
the frequency bands of pile driving (most energy below 2 kHz) compared to harbor porpoise
hearing (150 Hz to 160 kHz peaking around 40 kHz). Specifically, TTS is unlikely to impact
hearing ability in their more sensitive hearing ranges, or the frequencies in which they
communicate and echolocate. We expect any PTS that may occur to be within the very low end
of their hearing range where harbor porpoises are not particularly sensitive and any PTS would
be of small magnitude. As such, any PTS would not interfere with key foraging or reproductive
strategies necessary for reproduction or survival.
As discussed in the draft 2023 SARs (89 FR 5495, January 29, 2024), harbor porpoises
are seasonally distributed. During fall (October–December) and spring (April–June), harbor
porpoises are widely dispersed from New Jersey to Maine, with lower densities farther north and
south. During winter (January to March), intermediate densities of harbor porpoises can be found
in waters off New Jersey to North Carolina, and lower densities are found in waters off New
York to New Brunswick, Canada. In non-summer months they have been seen from the coastline
to deep waters (i.e., >1800 m; Westgate et al., 1998), although the majority are found over the
continental shelf. While harbor porpoises are likely to avoid the area during any of the Project’s
construction activities, as demonstrated during European wind farm construction, the time of
year in which work would occur is when harbor porpoises are not in highest abundance, and any
work that does occur would not result in the species’ abandonment of the waters off of
Massachusetts.
Given the magnitude and severity of the impacts discussed above, and in consideration of
the required mitigation and other information presented, the specified activities are not expected
to result in impacts on the reproduction or survival of any individuals, much less affect annual
rates of recruitment or survival. For these reasons, we have determined that the take by
harassment anticipated and that may be authorized will have a negligible impact on the Gulf of
Maine/Bay of Fundy stock of harbor porpoises.

Phocids (harbor seals, gray seals, and harp seals)
The harbor seal, gray seal, harp seal, and hooded seal are not listed under the ESA, and
neither the western North Atlantic stock of gray seal, western North Atlantic stock of harp seal,
nor the western North Atlantic stock of harbor seal are considered depleted or strategic under the
MMPA. There are no known areas of specific biological importance in or around the Project
Area. As described in the Description of Marine Mammals in the Geographic Area section, a
UME has been designated for harbor seals and gray seals and is described further below. No
serious injury or mortality is anticipated or may be authorized for these species.
For the four seal species, the rule would allow for the authorization of up to between 2
and 4,077 takes for each species by harassment only over the 5-year period. The maximum
annual allowable take for these species by Level A harassment and Level B harassment,
respectively, would be 0 and 1 (hooded seals), 18 and 1,301 (harbor seals), 9 and 1,537 (gray
seal), and 9 to 2,013 (harp seals) (this annual take equates to approximately <0.1 percent of the
stock abundance for harp seals, 5.54 percent of the stock abundance for gray seals, and 2.15
percent of the stock abundance for harbor seals). The population abundance of hooded seal is
unknown but, considering that no more than one hooded seal would be taken by Level B
harassment annually, it would be reasonable to assume this would constitute a small percentage
of the stock. For the four species, if each take were considered to be of a different individual),
with far lower numbers than that expected in the years without foundation installation (e.g., years
when only HRG surveys would be occurring). Though gray seals, harbor seals, and harp seals are
considered migratory and no specific feeding areas have been designated in the area, the higher
number of takes relative to the stock abundance suggests that while some of the takes likely
represent exposures of different individuals on 1 day a year, it is likely that some subset of the
individuals exposed could be taken several times annually. For hooded seals, given this species is
considered rare in the area, it is unlikely that individuals would remain in the project area for

multiple days, and therefore the estimated takes likely represent exposures of different
individuals on one day each annually.
Harbor, gray, and harp seals occur in Massachusetts waters most often in winter
(December through May), when most foundation installation and UXO/MEC detonations would
not occur due to seasonal restrictions on conducting these activities). Seals are also more likely
to be close to shore (e.g., closer to the edge of the area ensonified above NMFS’ harassment
threshold), such that exposure to foundation installation would be expected to be at
comparatively lower levels. Take of these species is noise from pile driving, drilling, UXO/MEC
detonations, and HRG surveys.
There are no gray seal pupping colonies or known haul-out sites near the Project Area,
although gray seals may haul out at known harbor seal haul out sites. The nearest known gray
seal pupping sites are greater than 100 nautical miles (nmi) (185 km) away, at Muskeget Island
in the Nantucket Sound, Monomoy National Wildlife Refuge, and in eastern Maine (Rough,
1995). Known haul out locations are located closer to Monomoy Refuge and on Nantucket in
Massachusetts (Kenney and Vigness-Raposa, 2010). Harbor seals have the potential to occur in
areas adjacent to the export cable corridors and landfall sites. Although there are no known
harbor seal haul outs in the Project Area, harbor seals occur throughout the Massachusetts
coastline and have the potential to haul out at many beach sites. As the closest documented
pinniped haul out sites are located further than 150 km away from the Project Area, NMFS does
not expect any harassment to occur and would not plan to authorize any take from in-air impacts
on hauled-out seals.
As described in the “Potential Effects to Marine Mammals and Their Habitat” section in
the proposed rule, construction of wind farms in Europe resulted in pinnipeds temporarily
avoiding construction areas but returning within short time frames after construction was
complete (Carroll et al., 2010; Hamre et al., 2011; Hastie et al., 2015; Russell et al., 2016;
Brasseur et al., 2010). Effects on pinnipeds that are taken by Level B harassment in the Project

Area would likely be limited to reactions such as avoidance in the form of increased swimming
speeds, increased surfacing time, or decreased foraging (if such activity were occurring). Most
likely, individuals would simply move away from the sound source and be temporarily displaced
from those areas (Lucke et al., 2006; Edren et al., 2010; Skeate et al., 2012; Russell et al., 2016).
Given the low anticipated magnitude of impacts from any given exposure (e.g., temporary
avoidance), even repeated Level B harassment across a few days of some small subset of
individuals, is unlikely to result in impacts on the reproduction or survival of any individuals.
Moreover, pinnipeds would benefit from the mitigation measures described in 50 CFR part 217.
As described above, noise from UXO/MEC detonation is low frequency and, while any
PTS and TTS that does occur would fall within the lower end of pinniped hearing ranges (50 Hz
to 86 kHz), PTS and TTS would not occur at frequencies where pinniped hearing is most
sensitive. In summary, any PTS and TSS would be of small degree and not occur across the
entire, or even most sensitive, hearing range. Hence, any impacts from PTS and TTS are likely to
be of low severity and not interfere with behaviors critical to reproduction or survival.
For harbor seals, the population abundance is over 61,000 and the annual
mortality/serious injury (M/SI; 339) for the seals is well below PBR (i.e., 1,729) (89 FR 5495,
January 29, 2024). The population abundance for gray seals in the United States is over 27,000,
with an estimated overall abundance, including seals in Canada, of approximately 366,400 (89
FR 5495, January 29, 2024). In addition, the abundance of gray seals is likely increasing in the
U.S. Atlantic, as well as in Canada (89 FR 5495, January 29, 2024). For harp seals and hooded
seals, for which there is no recent UME, the total U.S. fishery-related mortality and serious
injury for this stock is very low relative to the stock size and can be considered insignificant and
approaching zero mortality and serious injury rate (Hayes et al., 2019; Hayes et al., 2022). The
harp seal stock abundance appears to have stabilized (Hayes et al., 2022).
Given the magnitude and severity of the impacts from the specified activities discussed
above, and in consideration of the required mitigation and other information presented, the

specified activities are not expected to result in impacts on the reproduction or survival of any
individuals, much less affect annual rates of recruitment or survival. For these reasons, we have
determined that the take by harassment anticipated and may be authorized will have a negligible
impact on harbor, gray, harp, and hooded seals.
Negligible Impact Determination
No mortality or serious injury is anticipated to occur or may be authorized. As described
in the analysis above, the impacts resulting from the Project’s activities cannot be reasonably
expected to, and are not reasonably likely to, adversely affect any of the species or stocks
through effects on annual rates of recruitment or survival. Based on the analysis contained herein
of the likely effects of the specified activity on marine mammals and their habitat, and taking
into consideration the implementation of the required mitigation and monitoring measures,
NMFS finds that the marine mammal take from all of the specified activities combined will have
a negligible impact on all affected marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be authorized under sections
101(a)(5)(A) and (D) of the MMPA for specified activities other than military readiness
activities. The MMPA does not define small numbers; therefore, in practice, and where estimated
numbers are available, NMFS compares the number of individuals estimated to be taken to the
most appropriate estimation of abundance of the relevant species or stock in our determination of
whether an authorization is limited to small numbers of marine mammals. When the predicted
number of individuals to be taken is less than one-third of the species or stock abundance, the
take is considered to be of small numbers. Additionally, other qualitative factors may be
considered in the analysis, such as the temporal or spatial scale of the activities.
NMFS may authorize incidental take by Level A harassment and/or Level B harassment
of 38 species of marine mammals (with 38 managed stocks). The maximum number of instances
of takes by combined Level A harassment and Level B harassment possible within any one year

relative to the best available population abundance is less than one-third for all species and
stocks potentially impacted. Unless otherwise noted, the small numbers analysis conservatively
assumes each take occurs to a different individual in the population.
For 28 stocks, less than 6 percent of the stock abundance may be authorized for take by
harassment under this final rule. Specific to the North Atlantic right whale, the maximum amount
of take reasonably likely to occur per year, which is by Level B harassment only, is 60, or 17.65
percent of the stock abundance, assuming that each instance of take represents a different
individual. Please see table 35 for information relating to this small numbers analysis.
For seven species, there are no current abundance estimates available; hence the
percentage of the population taken is unknown. However, these constitute rare species and only a
small amount of take may be authorized each year under this final rule. For three of these
species, no more than five takes per year may be authorized under this final rule (hooded seal,
pygmy killer whale, and northern bottlenose whale). For the melon-headed whale, Fraser’s
dolphin, and killer whale, a maximum of 109, 192, and 10, respectively, takes are allowed under
this final rule, based on the prediction that a group may be encountered up to a few times during
the activity and representing approximately one to three average group sizes. Hence, the amount
of take for all rare species with unknown populations can reasonably be considered a small
number.
Based on the analysis contained herein of the activities (including the required mitigation
and monitoring measures) and the anticipated take of marine mammals, NMFS finds that small
numbers of marine mammals would be taken relative to the population size of the affected
species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine mammal stocks or species
implicated by this action. Therefore, NMFS has determined that the total taking of affected

species or stocks would not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
Classification
Endangered Species Act
Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.) requires that each Federal
agency ensure that any action it authorizes, funds, or carries out is not likely to jeopardize the
continued existence of any endangered or threatened species or result in the destruction or
adverse modification of designated critical habitat. To ensure ESA compliance for the
promulgation of rulemakings, NMFS consults internally whenever we propose to authorize take
for endangered or threatened species, and in this case, consulted with the NOAA GARFO.
This final rule allows for the take of five marine mammal species listed under the ESA:
the North Atlantic right, blue, sei, fin, and sperm whale. The Permit and Conservation Division
requested initiation of section 7 consultation with NMFS GARFO on May 9, 2023 for the
promulgation of the rulemaking. NMFS GARFO issued a BiOp on February 16, 2024,
concluding that the promulgation of the rule and issuance of LOAs thereunder is not likely to
jeopardize the continued existence of threatened and endangered species under NMFS’
jurisdiction and is not likely to result in the destruction or adverse modification of designated or
proposed critical habitat. The BiOp is available at
https://repository.library.noaa.gov/view/noaa/60610.
Avangrid is required to abide by the promulgated regulations, as well as the reasonable
and prudent measure and terms and conditions of the BiOp and Incidental Take Statement, as
issued by NMFS.
National Environmental Policy Act
To comply with NEPA (42 U.S.C. 4321 et seq.) and the NOAA Administrative Order
216-6A, NMFS must evaluate our proposed action (i.e., promulgation of regulation) and
alternatives with respect to potential impacts on the human environment. NMFS participated as a

cooperating agency on the BOEM 2024 Final EIS (FEIS), which was finalized on March 1,
2024, and is available at: https://www.boem.gov/renewable-energy/state-activities/new-englandwind-formerly-vineyard-wind-south. In accordance with 40 CFR 1506.3, NMFS independently
reviewed and evaluated the 2024 New England Wind FEIS and determined that it is adequate
and sufficient to meet our responsibilities under NEPA for the promulgation of this rule and
issuance of the associated LOA. NMFS, therefore, has adopted the 2024 New England Wind
FEIS through a joint Record of Decision (ROD) with BOEM. The joint ROD for adoption of the
2024 New England Wind FEIS and promulgation of this final rule and subsequent issuance of a
LOA can be found at: https://www.fisheries.noaa.gov/permit/incidental-take-authorizationsunder-marine-mammal-protection-act.
Executive Order 12866
The Office of Management and Budget (OMB) has determined that this rule is not
significant for purposes of Executive Order 12866.
Regulatory Flexibility Act
Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq.), the Chief Counsel for
Regulation of the Department of Commerce has certified to the Chief Counsel for Advocacy of
the Small Business Administration during the proposed rule stage that this action would not have
a significant economic impact on a substantial number of small entities. The factual basis for the
certification was published in the proposed rule and is not repeated here. No comments were
received regarding this certification. As a result, a regulatory flexibility analysis was not required
and none was prepared.
Paperwork Reduction Act
Notwithstanding any other provision of law, no person is required to respond to nor shall
a person be subject to a penalty for failure to comply with a collection of information subject to
the requirements of the Paperwork Reduction Act unless that collection of information displays a
currently valid OMB control number. These requirements have been approved by OMB under

control number 0648-0151 and include applications for regulations, subsequent LOA, and
reports. Send comments regarding any aspect of this data collection, including suggestions for
reducing the burden, to NMFS.
Coastal Zone Management Act
The Coastal Zone Management Act requires that any applicant for a required Federal
license or permit to conduct an activity, within the coastal zone or within the geographic location
descriptions (i.e., areas outside the coastal zone in which an activity would have reasonably
foreseeable coastal effects), affecting any land or water use or natural resource of the coastal
zone be consistent with the enforceable policies of a state’s federally approved coastal
management program. As required, in June 2022, Park City Wind (now Avangrid) submitted a
Federal consistency certification to Massachusetts Coastal Zone Management’s (MA CZM) and
to the Rhode Island Coastal Resources Management Council (CRMC) for approval of the COP
by BOEM and the issuance of an Individual Permit by United States Army Corps of Engineers,
under sections 10 and 14 of the Rivers and Harbors Act and section 404 of the Clean Water Act
(15 CFR part 930, subpart E).
NMFS determined that Avangrid's application for MMPA ITRs is an unlisted activity
under the State of New York’s coastal management program and, thus, is not subject to Federal
consistency requirements in the absence of the receipt and prior approval of an unlisted activity
review request from the State by the Director of NOAA's Office for Coastal Management.
Pursuant to 15 CFR 930.54, NMFS published a NOR for the application in the Federal Register
on August 22, 2022 (87 FR 51345), and published the proposed rule on June 8, 2023 (88 FR
37606). The states of Massachusetts and Rhode Island did not request approval from the Director
of NOAA's Office for Coastal Management to review the application as an unlisted activity, and
the time period for making such request has expired. Therefore, NMFS has determined the ITA
is not subject to Federal consistency review.

List of Subjects in 50 CFR Part 217
Administrative practice and procedure, Endangered and threatened species, Fish,
Fisheries, Marine mammals, Penalties, Reporting and recordkeeping requirements, Wildlife.
Dated: May 28, 2024.


Samuel D. Rauch III,
Deputy Assistant Administrator for Regulatory Programs,
National Marine Fisheries Service.

PART 217 – REGULATIONS GOVERNING THE TAKING AND IMPORTING OF
MARINE MAMMALS
1. The authority citation for part 217 continues to read as follows:
Authority: 16 U.S.C. 1361 et seq., unless otherwise noted.
2. Add subpart GG, consisting of §§ 217.320 through 217.329, to read as follows:
Subpart GG – Taking Marine Mammals Incidental to the New England Wind Project
Offshore of Massachusetts
Sec.
217.320 Specified activity and specified geographical region.
217.321 Effective dates.
217.322 Permissible methods of taking.
217.323 Prohibitions.
217.324 Mitigation requirements.
217.325 Requirements for monitoring and reporting.
217.326 Letter of Authorization.
217.327 Modifications of Letter of Authorization.
217.328 – 217.329 [Reserved]
Subpart GG – Taking Marine Mammals Incidental to the New England Wind Project
Offshore of Massachusetts

§ 217.320 Specified activity and specified geographical region.
(a) Regulations in this subpart apply only to activities associated with Phase 1 and Phase
2 of the New England Wind project (hereafter referred to as the “Project”) developed by
Avangrid Renewables, LLC, and its successors or assigns (hereafter referred to as the “LOA
Holder”), and those persons it authorizes or funds to conduct activities on its behalf in the area
outlined in paragraph (b) of this section. Requirements imposed on LOA Holder must be
implemented by those persons it authorizes or funds to conduct activities on its behalf.
(b) The specified geographical region is the Mid-Atlantic Bight, defined as waters from
Cape Hatteras, North Carolina to Cape Cod, Massachusetts and extending into the west Atlantic
to the 100-m isobath, and includes, but it not limited to, the Bureau of Ocean Energy
Management (BOEM) Lease Area Outer Continental Shelf (OCS)-A 0534, OCS-A 0561, and
portions of OCS-A 0501 Commercial Lease of Submerged Lands for Renewable Energy
Development, along export cable routes, and at the sea-to-shore transition points in Barnstable
County, Massachusetts.
(c) The specified activities are impact pile driving, vibratory pile driving, and drilling of
wind turbine generator (WTG) and electrical service platform (ESP) foundations; highresolution geophysical (HRG) site characterization surveys; detonation of unexploded
ordnances (UXOs) or munitions and explosives of concern (MECs); fisheries and benthic
monitoring surveys; placement of scour protection; trenching, laying, and burial activities
associated with the installation of the export cable from the ESP(s) to shore based converter
stations and inter-array cables between WTG foundations; vessel transit within the specified
geographical region to transport crew, supplies, and materials; and WTG operations.
§ 217.321 Effective dates.
Regulations in this subpart are effective from March 27, 2025, through March 26, 2030.

§ 217.322 Permissible methods of taking.
Under a Letter of Authorization (LOA) issued pursuant to § 216.106 of this chapter and
§ 217.326 or § 217.327, LOA Holder, and those persons it authorizes or funds to conduct
activities on its behalf, may incidentally, but not intentionally, take marine mammals within the
area described in § 217.320(b) in the following ways, provided LOA Holder is in complete
compliance with all terms, conditions, and requirements of the regulations in this subpart and
the appropriate LOA:
(a) By Level B harassment associated with the acoustic disturbance of marine mammals
by impact and vibratory pile driving and drilling (foundation installation), UXO/MEC
detonations, and HRG site characterization surveys;
(b) By Level A harassment associated with the acoustic disturbance of marine mammals
by impact pile driving of WTG and ESP foundations and UXO/MEC detonations;
(c) Take by mortality or serious injury of any marine mammal species is not authorized;
and
(d) The incidental take of marine mammals by the activities listed in paragraphs (a) and
(b) of this section is limited to the following species:
Table 1 to Paragraph (d)
Marine Mammal
Species
Atlantic spotted dolphin

Scientific Name

Stock

Stenella frontalis

Western North Atlantic

Atlantic white-sided
dolphin
Blainsville’s beaked whale

Lagenorhynchus acutus

Western North Atlantic

Mesoplodon densirostris

Western North Atlantic

Blue whale

Balaenoptera musculus

Western North Atlantic

Bottlenose dolphin

Tursiops truncatus

Clymene dolphin

Stenella clymene

Western North Atlantic,
offshore
Western North Atlantic

Cuvier’s beaked whale

Ziphius cavirostris

Western North Atlantic

Dwarf sperm whale

Kogia sima

Western North Atlantic

False killer whale

Pseudorca crassidens

Western North Atlantic

Fin whale

Balaenoptera physalus

Western North Atlantic

Fraser’s dolphin

Lagenodelphis hosei

Western North Atlantic

Gervais’ beaked whale

Mesoplodon europaeus

Western North Atlantic

Gray seal

Halichoerus grypus

Western North Atlantic

Harbor porpoise

Phocoena phocoena

Harbor seal

Phoca vitulina

Gulf of Maine/Bay of
Fundy
Western North Atlantic

Harp seal

Pagophilus groenlandicus

Western North Atlantic

Hooded seal

Cystophora cristata

Western North Atlantic

Humpback whale

Megaptera novaeangliae

Gulf of Maine

Killer whale

Orcinus orca

Western North Atlantic

Long-finned pilot whale

Globicephala melas

Western North Atlantic

Melon-headed whale

Peponocephala electra

Western North Atlantic

Minke whale

Balaenoptera acutorostrata

Canadian Eastern Coastal

North Atlantic right whale

Eubalaena glacialis

Western North Atlantic

Northern bottlenose whale

Hyperoodon ampullatus

Western North Atlantic

Pantropical spotted dolphin

Stenella attenuata

Western North Atlantic

Pygmy killer whale

Feresa attenuata

Western North Atlantic

Pygmy sperm whale

Kogia breviceps

Western North Atlantic

Risso’s dolphin

Grampus griseus

Western North Atlantic

Rough-toothed dolphin

Steno bredanensis

Western North Atlantic

Sei whale

Balaenoptera borealis

Nova Scotia

Short-beaked common
dolphin
Short-finned pilot whale

Delphinus delphis

Western North Atlantic

Globicephala macrorhynchus

Western North Atlantic

Sowerby’s beaked whale

Mesoplodon bidens

Western North Atlantic

Sperm whale

Physeter macrocephalus

Western North Atlantic

Spinner dolphin

Stenella longirostris

Western North Atlantic

Striped dolphin

Stenella coeruleoalba

Western North Atlantic

True’s beaked whale

Mesoplodon mirus

Western North Atlantic

White-beaked dolphin

Lagenorhynchus albirostris

Western North Atlantic

§ 217.323 Prohibitions.
Except for the takings described in § 217.322 and authorized by a LOA issued under §
217.326 or § 217.327, it is unlawful for any person to do any of the following in connection
with the activities described in this subpart:
(a) Violate, or fail to comply with, the terms, conditions, and requirements of this
subpart or a LOA issued under this subpart;
(b) Take any marine mammal not specified in § 217.322(d);
(c) Take any marine mammal specified in § 217.322(d) in any manner other than as
specified in § 217.322(a) and (b); or
(d) Take any marine mammal specified in § 217.322(d), after NMFS Office of Protected
Resources determines such taking results in more than a negligible impact on the species or
stocks of such marine mammals.
§ 217.324 Mitigation requirements.
When conducting the specified activities in the specified geographical region, LOA
Holder must implement the following mitigation measures contained in this section and any
LOA issued under §§ 217.326 and 217.327. These mitigation measures include, but are not
limited to:
(a) General conditions. LOA Holder must comply with the following general measures:
(1) A copy of any issued LOA must be in the possession of LOA Holder and its
designees, all vessel operators, visual protected species observers (PSOs), passive acoustic
monitoring (PAM) operators, pile driver operators, and any other relevant designees operating
under the authority of the issued LOA;

(2) LOA Holder must conduct training for construction, survey, and vessel personnel
and the marine mammal monitoring team (PSO and PAM operators) prior to the start of all inwater construction activities in order to explain responsibilities, communication procedures,
marine mammal detection and identification, mitigation, monitoring, and reporting
requirements, safety and operational procedures, and authorities of the marine mammal
monitoring team(s). This training must be repeated for new personnel who join the work during
the project. A description of the training program must be provided to NMFS at least 60 days
prior to the initial training before in-water activities begin. Confirmation of all required training
must be documented on a training course log sheet and reported to NMFS Office of Protected
Resources prior to initiating project activities;
(i) A copy of the Marine Mammal Monitoring Plan must be made available on all
vessels and staffed platforms. A simple guide must be included with the Marine Mammal
Monitoring Plan to aid personnel in identifying species if they are observed in the vicinity of the
project area.
(ii) [Reserved]
(3) Prior to and when conducting any in-water activities and vessel operations, LOA
Holder personnel and contractors (e.g., vessel operators, PSOs) must use available sources of
information on North Atlantic right whale presence in or near the Project Area including daily
monitoring of the Right Whale Sightings Advisory System, and monitoring of Coast Guard
VHF Channel 16 throughout the day to receive notification of any sightings and/or information
regarding the establishment of mandatory or voluntary speed restrictions (e.g., Dynamic
Management Areas (DMAs), Seasonal Management Areas (SMAs), and/or acousticallytriggered slow zones),and any information regarding North Atlantic right whale sighting
locations to provide situational awareness for both vessel operators, PSO(s), and PAM
operators; The marine mammal monitoring team must monitor these systems no less than every
4 hours;

(4) Any marine mammal observed by project personnel must be immediately
communicated to any on-duty PSOs, PAM operator(s), and all vessel captains. Any large whale
observation or acoustic detection by PSOs or PAM operators must be conveyed to all vessel
captains;
(5) LOA Holder must establish and implement minimum visibility, clearance, and
shutdown zones as described in the LOA. For North Atlantic right whales, any visual detection
by a PSO at any distance or acoustic detection by PAM operators within the PAM monitoring
zone (where applicable for the specified activities) must trigger a delay to the commencement of
pile driving (i.e., impact pile driving and vibratory pile driving) and drilling;
(6) PSOs and PAM operators have the authority to call for a delay or shutdown to an
activity, and LOA Holder must instruct all vessel personnel regarding the authority of the PSOs
and PAM operators. If a delay to commencing an activity is called for by the Lead PSO or PAM
operator, LOA Holder must take the required mitigative action. If a shutdown of an activity is
called for by a PSO or PAM operator, LOA Holder must take the required mitigative action
unless shutdown would result in imminent risk of injury or loss of life to an individual, pile
refusal, or pile instability. Any disagreement between the PSO, PAM operator, and the activity
operator regarding delays or shutdowns must only be discussed after the mitigative action has
occurred;
(7) If an individual from a species for which authorization has not been granted, or a
species for which authorization has been granted but the authorized take number has been met,
is observed entering or within the relevant clearance zone prior to beginning a specified activity
(e.g., pile driving (impact and vibratory), drilling, UXO/MEC detonations, and HRG acoustic
sources), the activity must be delayed. If an activity is ongoing and individual from a species for
which authorization has not been granted, or a species for which authorization has been granted
but the authorized take number has been met, is observed entering or within the relevant
shutdown zone, the activity must be shut down (i.e., cease) immediately, unless shutdown

would result in imminent risk of injury or loss of life to an individual, pile refusal, or pile
instability. The activity must not commence or resume until the animal(s) has been confirmed to
have left the clearance area and is on a path away from the applicable zone or after 15 minutes
with no further sightings for small odontocetes and pinnipeds or 30 minutes with no further
sightings for all other species;
(8) Foundation installation (i.e., impact and vibratory pile driving, drilling), UXO/MEC
detonation, and HRG survey activities must only commence when minimum visibility zones
(for UXO/MEC detonations the visual clearance zones) are fully visible (e.g., not obscured by
darkness, rain, fog, etc.) and the clearance zones are clear of marine mammals, as determined by
the Lead PSO, for at least 30 minutes immediately prior to initiation of equipment (i.e.,
vibratory and impact pile driving, drilling, UXO/MEC detonations, and HRG surveys that use
boomers, sparkers). Any marine mammals observed within a clearance or shutdown zone must
be allowed to remain in the area (i.e., must leave of their own volition) prior to commencing
foundation installation activities, UXO/MEC detonation, or HRG surveys
(9) In the event that a large whale species is sighted or acoustically detected that cannot
be confirmed as a non-North Atlantic right whale, it must be treated as if it were a North
Atlantic right whale for purposes of mitigation;
(10) For in-water construction heavy machinery activities listed in § 217.320(c), if a
marine mammal is on a path towards or comes within 10 meters (m; 32.8 feet (ft)) of
equipment, LOA Holder must cease operations until the marine mammal has moved more than
10 m on a path away from the activity to avoid direct interaction with equipment;
(11) All vessels must be equipped with a properly installed, operational Automatic
Identification System (AIS) device and LOA Holder must report all Maritime Mobile Service
Identify (MMSI) numbers to NMFS Office of Protected Resources;
(12) By accepting the LOA, LOA Holder consents to on-site observation and inspections
by Federal agency personnel (including NOAA personnel) during activities described in this

subpart, for the purposes of evaluating the implementation and effectiveness of measures
contained within the LOA and this subpart; and
(13) It is prohibited to assault, harm, harass (including sexually harass), oppose, impede,
intimidate, impair, or in any way influence or interfere with a PSO, PAM operator, or vessel
crew member acting as an observer, or attempt the same. This prohibition includes, but is not
limited to, any action that interferes with an observer's responsibilities, or that creates an
intimidating, hostile, or offensive environment. Personnel may report any violations to the
NMFS Office of Law Enforcement.
(b) Vessel strike avoidance measures. LOA Holder must comply with the following
vessel strike avoidance measures while in the specified geographical region, unless a deviation
is necessary to maintain safe maneuvering speed and justified because the vessel is in an area
where oceanographic, hydrographic, and/or meteorological conditions severely restrict the
maneuverability of the vessel; an emergency situation presents a threat to the health, safety, life
of a person; or when a vessel is actively engaged in emergency rescue or response duties,
including vessel-in distress or environmental crisis response. An emergency is defined as a
serious event that occurs without warning and requires immediate action to avert, control, or
remedy harm.
(1) Prior to the start of the Project’s activities involving vessels, all vessel personnel
must receive a protected species training that covers, at a minimum: Identification of marine
mammals that have the potential to occur in the specified geographical region; detection and
observation methods in good weather conditions (i.e., clear visibility, low winds, low sea states)
and bad weather conditions (i.e., fog, high winds, high sea states, with glare); sighting
communication protocols; all vessel strike avoidance mitigation requirements; and information
and resources available to the project personnel regarding the applicability of Federal laws and
regulations for protected species. This training must be repeated for any new vessel personnel
who join the Project.

(i) Confirmation of the vessel personnel’s training and understanding of the LOA
requirements must be documented on a training course log sheet and reported to NMFS Office
of Protected Resources prior to vessel activities.
(ii) [Reserved]
(2) All vessel operators and dedicated visual observers must maintain a vigilant watch
for all marine mammals and slow down, stop their vessel, or alter course to avoid striking any
marine mammal;
(3) All underway vessels operating at any speed must have a dedicated visual observer
on duty at all times to monitor for marine mammals within a 180 degree direction of the
forward path of the vessel (90 degree port to 90 degree starboard) located at an appropriate
vantage point for ensuring vessels are maintaining appropriate separation distances. Dedicated
visual observers may be third-party observers (i.e., NMFS-approved PSOs; see § 217.325(a)) or
trained crew members (see paragraph (b)(1) of this section). Dedicated visual observers must be
equipped with alternative monitoring technology (e.g., night vision devices, infrared cameras)
for periods of low visibility (e.g., darkness, rain, fog, etc.). The dedicated visual observer must
not have any other duties while observing for marine mammals and must receive prior training
on protected species detection and identification, vessel strike avoidance procedures, how and
when to communicate with the vessel captain, and reporting requirements in this subpart;
(4) All vessel operators and dedicated visual observers on each transiting vessel must
continuously monitor U.S. Coast Guard VHF Channel 16, at the onset of transiting through the
duration of transiting, over which North Atlantic right whale sightings are broadcasted. At the
onset of transiting and at least once every 4 hours, vessel operators and/or trained crew
member(s) must also monitor the project’s Situational Awareness System (if applicable),
WhaleAlert, and relevant NOAA information systems such as the Right Whale Sighting
Advisory System (RWSAS) for the presence of North Atlantic right whales. Any large whale

sighting by any Project personnel must be communicated immediately to all project-associated
vessels;
(5) Any observations of any large whale by any LOA Holder staff or contractor,
including vessel crew, must be communicated immediately to on-duty PSOs, PAM operators,
and all vessel captains to increase situational awareness;
(6) All vessel operators must abide by existing applicable vessel speed regulations (50
CFR 224.105). Nothing in this subpart exempts vessels from any other applicable marine
mammal speed or approach regulations;
(7) Vessels, regardless of size, must not travel over 10 kn (11.5 mph) from November
1st through April 30th, annually, in the specified geographical region. During all other time
periods, all vessels must transit active Slow Zones (i.e., DMAs or acoustically-triggered slow
zone), and SMAs at 10 kn or less (11.5 mph);
(i) If vessel(s) are traveling at speeds greater than 10 kn (11.5 mph) (i.e., no speed
restrictions are enacted) in the transit corridor (defined as from a port to the Lease Area or
return), in addition to the required dedicated visual observer, LOA Holder must monitor the
transit corridor in real-time with PAM prior to and during transits.
(ii) [Reserved]
(8) All vessels operators, regardless of their vessel’s size, must immediately reduce
speed to 10 kn or less when any large whale (other than a North Atlantic right whale),
mother/calf pairs, or large assemblages of cetaceans are observed within 500 m (0.31 mi) of a
transiting vessel;
(9) All vessels, regardless of size, must immediately reduce speed to 10 kn (11.5 mph)
or less for at least 24 hours when a North Atlantic right whale is sighted at any distance by any
project related personnel or acoustically detected by any project-related PAM system. Each
subsequent observation or acoustic detection in the Project area must trigger an additional 24hour period. If a North Atlantic right whale is reported via any of the monitoring systems

(described in paragraph (b)(4) of this section) within 10 km of a transiting vessel(s), that vessel
must operate at 10 kn (11.5 mph) or less for 24 hours following the reported detection. A
slowdown in the transit corridor expires when there has been no further visual or acoustic
detection in the transit corridor in the past 24 hours;
(10) All vessels must maintain a minimum separation distance of 500 m from North
Atlantic right whales. If underway, all vessels must steer a course away from any sighted North
Atlantic right whale at 10 kn (11.5 mph) or less such that the 500-m minimum separation
distance requirement is not violated. If a North Atlantic right whale is sighted within 500 m of
an underway vessel, that vessel must turn away from the whale(s), reduce speed and shift the
engine to neutral. Engines must not be engaged until the whale has moved outside of the
vessel’s path and beyond 500 m. All vessels must comply with North Atlantic right whale
approach restrictions at 50 CFR 224.103(c);
(11) All vessels must maintain a minimum separation distance of 100 m (328 ft) from
sperm whales and non-North Atlantic right whale baleen whales. If one of these species is
sighted within 100 m of a transiting vessel, that vessel must turn away from the whale(s), reduce
speed, and shift the engine(s) to neutral. Engines must then not be engaged until the whale has
moved outside of the vessel’s path and beyond 100 m;
(12) All vessels must maintain a minimum separation distance of 50 m from all
delphinid cetaceans and pinnipeds with an exception made for those that approach the vessel
(e.g., bow-riding dolphins). If a delphinid cetacean or pinniped is sighted within 50 m of a
transiting vessel, that vessel must turn away from the animal(s), reduce speed, and shift the
engine to neutral, with an exception made for those that approach the vessel (e.g., bow-riding
dolphins). Engines must not be engaged until the animal(s) has moved outside of the vessel’s
path and beyond 50 m;
(13) When a marine mammal(s) is sighted while a vessel is transiting, the vessel must
take action as necessary to avoid violating the relevant separation distances (e.g., attempt to

remain parallel to the animal’s course, slow down, and avoid abrupt changes in direction until
the animal has left the area). This measure does not apply to any vessel towing gear or any
situation where respecting the relevant separation distance would be unsafe (i.e., any situation
where the vessel is navigationally constrained);
(14) All vessels underway must not divert or alter course to approach any marine
mammal; and
(15) LOA Holder must submit a Marine Mammal Vessel Strike Avoidance Plan to
NMFS Office of Protected Resources for review and approval at least 180 days prior to the
planned start of vessel activity. The plan must provide details on the vessel-based observer and
PAM protocols for transiting vessels. The plan must also provide details on the transit corridor.
If a plan is not submitted and approved by NMFS prior to vessel operations, all project vessels
must travel at speeds of 10 kn (11.5 mph) or less. LOA Holder must comply with any approved
Marine Mammal Vessel Strike Avoidance Plan.
(c) WTG and ESP foundation installation. The following requirements apply to impact
and vibratory pile driving and drilling activities associated with the installation of WTG and
ESP foundations:
(1) Impact pile driving and drilling must not occur January 1 through April 30, annually.
Impact pile driving and drilling must not be planned in December; however, it may only occur
if necessary to complete the Project within a given year with prior approval by NMFS. LOA
Holder must notify NMFS in writing by September 1 of that year that pile driving or drilling
cannot be avoided and circumstances are expected to necessitate pile driving or drilling in
December;
(2) Vibratory pile driving (e.g., vibratory setting of piles) must not occur December 1May 31, annually;
(3) Monopiles must be no larger than 13-m in diameter. Pin piles must be no larger than
4 m in diameter. During all monopile and pin pile installation, the minimum amount of hammer

energy necessary to effectively and safely install and maintain the integrity of the piles must be
used. Hammer energies must not exceed 6,000 kilojoules (kJ) for monopile installations and
3,500 kJ for pin pile installation. No more than two monopiles or four pin piles may be installed
per day. No concurrent pile driving (i.e., impact pile driving or vibratory pile driving) or drilling
may occur. All mitigation measures required for or applicable to jacket foundations are required
for bottom-frame foundations that utilize pile foundations;
(i) LOA Holder must not initiate foundation installation (impact pile driving, vibratory
pile driving, and drilling) except during daylight hours; daylight hours are defined as no earlier
than 1 hour after civil sunrise and no later than 1.5 hours prior to civil sunset. Foundation
installation may only continue into darkness if stopping operations represents a risk to human
health, safety, and/or pile stability; and
(ii) LOA Holder must not initiate pile driving or drilling earlier than 1 hour after civil
sunrise or later than 1.5 hours prior to civil sunset, unless LOA Holder submits, and NMFS
approves, an Alternative Monitoring Plan for Nighttime Foundation Installation (i.e., Nighttime
Foundation Installation Plan), that demonstrates the efficacy of their night vision devices to
effectively monitor the mitigation zones. LOA Holder must submit this plan or plans (if
separate Daytime Reduced Visibility and Nighttime Monitoring Plans are prepared) at least 180
calendar days before foundation installation is planned to begin. This plan(s) must include, but
is not limited to, a complete description of how LOA Holder will monitor foundation
installation activities during reduced visibility conditions (e.g., rain, fog) and at night, including
proof of the efficacy of monitoring devices (e.g., mounted thermal/infrared camera systems,
hand-held or wearable night vision devices NVDs, spotlights) in detecting marine mammals
over the full extent of the required clearance and shutdown zones, including demonstration that
the full extent of the minimum visibility zones can be effectively and reliably monitored. The
plan must identify the efficacy of the technology at detecting marine mammals in the clearance
and shutdown zones under all the various conditions anticipated during construction, including

varying weather conditions, sea states, and in consideration of the use of artificial lighting. If the
plan does not include a full description of the proposed technology, monitoring methodology,
and data demonstrating to NMFS Office of Protected Resources’ satisfaction that marine
mammals can reliably and effectively be detected within the clearance and shutdown zones for
monopiles and pin pile before and during pile driving and drilling, nighttime foundation
installation (unless a pile was initiated 1.5 hours prior to civil sunset) may not occur.
Additionally, this plan must contain a thorough description of how LOA Holder will monitor
foundation installation activities during daytime when unexpected changes to lighting or
weather occur during pile driving (i.e., impact or vibratory) or drilling that prevent visual
monitoring of the full extent of the clearance and shutdown zones.
(4) LOA Holder must utilize soft-start at the beginning of monopile and pin pile impact
pile driving and at any time following a cessation of impact pile driving of 30 minutes or
longer;
(5) LOA Holder must establish clearance and shutdown zones, which must be measured
using the radial distance around the pile driving or drilling location;
(6) LOA Holder must utilize PSO(s) and PAM operator(s), as described in § 217.325. At
least nine on-duty PSOs must be actively observing marine mammals before, during, and after
installation of foundation piles (i.e., monopiles and pin piles). At least three on-duty PSOs must
be stationed and observing on the foundation installation vessel/platform. A minimum of three
PSOs must be active on each of the two dedicated PSO vessels. On-duty PSOs must be located
at the best vantage point to observe and document marine mammal sightings in proximity to the
clearance and, if applicable, shutdown zones. Concurrently, at least one PAM operator must be
actively monitoring for marine mammals with PAM 60 minutes before, during, and 30 minutes
after pile driving and drilling in accordance with a NMFS-approved PAM Plan;
(7) PSOs must visually monitor clearance zones for marine mammals for a minimum of
60 minutes prior to commencing pile driving or drilling. At least one PAM operator must

review data from at least 24 hours prior to pile driving or drilling and actively monitor
hydrophones for 60 minutes prior to, at all times during, and for 30 minutes after pile driving
and drilling. The entire minimum visibility zone must be visible (i.e., not obscured by dark,
rain, fog, etc.) for a full 60 minutes immediately prior to commencing pile driving or drilling.
All clearance zones must be confirmed to be free of marine mammals for 30 minutes
immediately prior to the beginning of pile driving, drilling, and soft-start procedures. PAM
operators must immediately communicate all detections of marine mammals at any distance to
the Lead PSO, including any determination regarding species identification, distance, and
bearing and the degree of confidence in the determination;
(8) If a marine mammal is detected within or about to enter the applicable clearance
zones during the clearance periods defined in paragraph (c)(7) of this section, activities must be
delayed until the animal has been visually observed exiting the clearance zone or until a specific
time period has elapsed with no further sightings. The specific time periods are 15 minutes for
small odontocetes and pinnipeds and 30 minutes for all other species;
(i) For foundation installation activities between May 1–May 14 and November 1–
December 31, if a North Atlantic right whale is observed at any distance or acoustically
detected within the PAM monitoring zone of the pile being driven (impact or vibratory) or area
being drilled, pile driving and drilling must be delayed or stopped (unless activities must
proceed for human safety or installation feasibility concerns) and may not resume until the
following day or until the animal is confirmed to have exited the zone via aerial or additional
vessel surveys;
(ii) [Reserved]
(9) LOA Holder must deploy at least two functional noise abatement systems that reduce
noise levels to the modeled harassment isopleths, assuming 10-dB attenuation, during all pile
driving and drilling and comply with the following measures:
(i) A single bubble curtain must not be used;

(ii) A big double bubble curtain may be used without being paired with another noise
attenuation device;
(iii) The bubble curtain(s) must distribute air bubbles using an air flow rate of at least
0.5 m3/(min*m). The bubble curtain(s) must surround 100 percent of the piling perimeter
throughout the full depth of the water column. In the unforeseen event of a single compressor
malfunction, the offshore personnel operating the bubble curtain(s) must adjust the air supply
and operating pressure such that the maximum possible noise attenuation performance of the
bubble curtain(s) is achieved;
(iv) The lowest bubble ring must be in contact with the seafloor for the full
circumference of the ring, and the weights attached to the bottom ring must ensure 100-percent
seafloor contact;
(v) No parts of the ring or other objects may prevent full seafloor contact with a bubble
curtain ring;
(vi) Construction contractors must train personnel in the proper balancing of airflow to
the bubble curtain ring. LOA Holder must provide NMFS Office of Protected Resources with a
bubble curtain performance test and maintenance report to review within 72 hours after each
pile using a bubble curtain is installed. Additionally, a full maintenance check (e.g., manually
clearing holes) must occur prior to each pile being installed;
(vii) Corrections to the bubble ring(s) to meet the performance standards in this
paragraph (c)(9) must occur prior to pile driving and drilling of foundation piles. For any noise
mitigation device in addition to the bubble curtain, LOA Holder must inspect and carry out
appropriate maintenance on the system and ensure the system is functioning properly prior to
every pile driving event; and
(viii) LOA Holder must inspect and carry out appropriate maintenance on the noise
attenuation system prior to every foundation installation event (i.e., for each pile driven
foundation) and UXO/MEC detonation and prepare and submit a Noise Attenuation System

(NAS) inspection/performance report to NMFS Office of Protected Resources. For piles for
which Thorough sound field verification (SFV) is carried out, this report must be submitted as
soon as it is available, but no later than when the interim SFV report is submitted for the
respective pile.
(10) PAM operator(s) must review data from at least 24 hours prior to pile driving and
drilling and actively monitor hydrophones for 60 minutes prior to pile driving and drilling. All
clearance zones must be acoustically confirmed to be free of marine mammals for 60 minutes
before activities can begin immediately prior to starting vibratory pile driving, drilling, and a
soft-start of impact pile driving. PAM operators will continue to monitor for marine mammals
for at least 30 minutes after pile driving or drilling concludes. The exact details for PAM
requirements must be submitted to NMFS within the PAM plan;
(i) LOA Holder must implement PAM in accordance with the NMFS-approved PAM
Plan, as described in § 217.325(c)(9). The PAM system components (i.e., acoustic buoys) must
not be placed closer than 1 km (0.6 mi) to the pile being driven so that the activities do not mask
the PAM system. LOA Holder must demonstrate and prove the detection range of the system
they plan to deploy while considering potential masking from concurrent pile-driving and vessel
noise. The PAM system must be designed to detect all marine mammals to the maximum extent
practicable, maximize baleen whale detections, and must be capable of detecting North Atlantic
right whales within the PAM monitoring zone;
(ii) [Reserved]
(11) For North Atlantic right whales, any visual observation by a PSO at any distance or
acoustic detection within the PAM Monitoring Zone must trigger a delay to the commencement
of pile driving. The North Atlantic right whale clearance zone may only be declared clear if no
North Atlantic right whale acoustic or visual detections have occurred within the clearance zone
during the 60-minute monitoring period. Any large whale sighting by a PSO or detected by a

PAM operator that cannot be identified as a non-North Atlantic right whale must be treated as if
it were a North Atlantic right whale;
(12) If a marine mammal is detected (visually or acoustically) entering or within the
respective shutdown zone after pile driving has begun, the PSO or PAM operator must call for a
shutdown of pile driving or drilling. If a marine mammal is detected entering or within the
respective shutdown zone after pile driving or drilling has begun, LOA Holder must stop pile
driving or drilling immediately unless shutdown is not practicable due to imminent risk of
injury or loss of life to an individual or risk of damage to a vessel that creates risk of injury or
loss of life for individuals, or the lead engineer determines there is pile refusal or pile instability.
If pile driving or drilling is not shut down, LOA Holder must reduce hammer energy to the
lowest level practicable and the reason(s) for not shutting down must be documented and
reported to NMFS Office of Protected Resources within the applicable monitoring reports (e.g.,
weekly, monthly) (see § 217.325(f));
(13) A visual observation or acoustic detection of a North Atlantic right whale at any
distance by PSOs or an acoustic detection within the PAM monitoring zone triggers shutdown
requirements under paragraph (c)(12) of this section. If pile driving or drilling has been shut
down due to the presence of a North Atlantic right whale, pile driving or drilling may not restart
until the North Atlantic right whale has neither been visually or acoustically detected by on-duty
PSOs and PAM operators for 30 minutes;
(14) If pile driving or drilling has been shut down due to the presence of a marine
mammal other than a North Atlantic right whale, pile driving or drilling must not restart until
either the marine mammal(s) has voluntarily left the specific clearance zones and has been
visually or acoustically confirmed beyond that clearance zone, or, when specific time periods
have elapsed with no further sightings or acoustic detections have occurred. The specific time
periods are 15 minutes for small odontocetes and pinnipeds and 30 minutes for all other marine
mammal species. In cases where these criteria are not met, pile driving may restart only if

necessary to maintain pile stability at which time LOA Holder must use the lowest hammer
energy practicable to maintain stability; and
(15) LOA Holder must conduct SFV during the following foundation installation
activities in accordance with the following requirements:
(i) For the first construction year, Thorough SFV must be conducted for the first three
monopiles installed with only an impact hammer (i.e., impact pile driving); the first three
monopiles installed with a vibratory hammer (i.e., vibratory pile driving or setting) followed by
an impact hammer; the first two jacket foundations (all piles) installed; the first foundation
(regardless of type) where drilling is used; the first monopile and first jacket foundation (all
piles) installed in December (winter sound speed profile); and, the first foundation for any
foundation scenarios that were modeled for the exposure analysis (e.g., rated hammer energy,
number of strikes, representative location) that does not fall into one of the previously listed
categories (e.g., if the first two jacket foundation are installed with only an impact hammer,
Thorough SFV would be required for the first jacket foundation installed with vibratory and
impact pile driving);
(ii) For any subsequent construction year, Thorough SFV must be conducted on the first
monopile and first jacket foundation (all piles) if there are no changes to the pile driving
equipment (e.g., same hammer, same Noise Attenuation System); Thorough SFV requirements
for the first construction year apply if a revised Facilities Design Report and Fabrication and
Installation Report (FDR/FIR) or other information is submitted to BOEM and Bureau of Safety
and Environmental Enforcement (BSEE) that details changes to the equipment (e.g., different
hammer, different noise attenuation system); if any foundation type or technique included in the
requirements for the first construction year that was not installed until a subsequent construction
year (e.g., if drilling is not used until year 2 or 3, the first foundation where relief drilling is
used must have Thorough SFV);

(iii) During Thorough SFV, installation of the next foundation (of the same
type/foundation method) may not proceed until LOA Holder has reviewed the initial results
from the Thorough SFV and determined that there were no exceedances of any distances to the
identified thresholds based on modeling assuming 10 dB attenuation. Subsequent SFV
measurements are also required should larger piles be installed or if additional monopiles are
driven that may produce louder sound fields than those previously measured (e.g., higher
hammer energy, greater number of strikes, etc.). If any of the Thorough SFV measurements
from any pile indicate that the distance to any isopleth of concern for any species is greater than
those modeled assuming 10 dB attenuation, LOA Holder must notify NMFS within 24 hours of
reviewing the Thorough SFV measurements and must implement the following measures for the
next pile of the same type/installation methodology, as applicable;
(iv) If any of the Thorough SFV measurements indicate that the distances to level A
thresholds for marine mammals (peak or cumulative) are greater than the modeled distances
(assuming 10 dB attenuation), the clearance and shutdown zones for subsequent piles of the
same type (e.g., if triggered by SFV results for a monopile, for the next monopile) must be
increased so that they are at least the size of the distances to those thresholds as indicated by
SFV. For every 1,500 m that a marine mammal clearance or shutdown zone is expanded,
additional PSOs must be deployed from additional platforms/vessels to ensure adequate and
complete monitoring of the expanded shutdown and/or clearance zone; LOA Holder must
deploy any additional PSOs consistent with the approved Marine Mammal Monitoring Plan in
consideration of the size of the new zones and the species that must be monitored use of the
expanded clearance and shutdown zones must continue for additional piles until LOA Holder
requests and receives concurrence from NMFS Office of Protected Resources and Greater
Atlantic Regional Fisheries Office (GARFO) to revert to the original clearance and shutdown
zones. LOA Holder must identify one or more additional, modified, and/or alternative noise
attenuation measure(s) and/or operational change(s) included in the approved SFV plan that is

expected to reduce sound levels to the modeled distances and must implement that measure for
the next pile of the same type and pile driving method that is installed (e.g., if triggered by SFV
results for a monopile installed with vibratory pile driving followed by impact pile driving, for
the next monopile with vibratory pile driving followed by impact pile driving). Attenuation
measures that could reduce sound levels to the modeled distances include but are not limited to
adding a noise attenuation device, adjusting hammer operations, and adjusting or otherwise
modifying the noise mitigation system. LOA Holder must provide written notification to NMFS
Office of Protected Resources of the changes implemented within 24 hours of their
implementation. Following installation of a pile with additional, alternative, or modified noise
attenuation measures/operational changes if Thorough SFV results indicate that all isopleths of
concern are within distances to isopleths of concern modeled assuming 10 dB attenuation,
Thorough SFV must be conducted on two additional piles of the same type/installation method
(for a total of at least three piles with consistent noise attenuation measures). If the Thorough
SFV results from all three of those piles are within the distances to isopleths of concern
modeled assuming 10 dB attenuation, then LOA Holder must continue to implement the
approved additional, alternative, or modified noise attenuation measures/operational changes.
LOA Holder can request concurrence from NMFS Office of Protected Resources to return to the
original clearance and shutdown zones;
(v) In addition to this SFV monitoring, which will follow a specific comprehensive
methodology described in the SFV Plan required in § 217.325(c)(8), LOA Holder also must
conduct Abbreviated SFV for all other foundations, using at least one acoustic recorder for
every foundation for which thorough SFV monitoring is not conducted. Abbreviated SFV
consists of: SFV measurements made at a single acoustic recorder, consisting of a near-bottom
and mid-water hydrophone, at approximately 750 m from the pile, in the direction of lowest
modeled transmission loss, to record sounds throughout the duration of all pile driving
(inclusive of relief drilling) of each foundation. If measured levels from Abbreviated SFV for

any pile are greater than expected levels, LOA Holder must evaluate the available information
from the pile installation to determine if there is an identifiable cause of the exceedance (i.e., a
failure of the noise attenuation system), identify and implement corrective action, and report
this information to NMFS Office of Protected Resources within 48 hours of completion of the
installation of the pile (inclusive of all pile driving and drilling), during which the exceedance
occurred. If LOA Holder can demonstrate that the exceedance was the result of a failure of the
noise attenuation system (e.g., loss of a generator supporting a bubble curtain such that one
bubble curtain failed during pile driving) that can be remedied in a way that returns the noise
attenuation system to pre-failure conditions, LOA Holder can request concurrence from NMFS
Office of Protected Resources to proceed without Thorough SFV monitoring that would
otherwise be required within 72 hours. LOA Holder is required to remedy any such failure of
the noise attenuation system prior to carrying out any additional pile driving or drilling.
(vi) Thorough SFV measurements must be made at a minimum of four distances from
the pile(s) being driven, along a single transect, in the direction of lowest transmission loss (i.e.,
projected lowest transmission loss coefficient), including, but not limited to, 750 m (2,460 ft)
and three additional ranges, including at least, the modeled Level B harassment isopleth zones
assuming 10 dB attenuation. At least one additional measurement at an azimuth 90 degrees
from the array at 750 m must be made. At each location, there must be a near bottom and midwater column hydrophone (measurement system).
(vii) The recordings must be continuous throughout the duration of all pile driving and
drilling of each foundation.
(viii) The SFV measurement systems must have a sensitivity appropriate for the
expected sound levels from pile driving and drilling received at the nominal ranges throughout
the installation of the pile. The frequency range of SFV measurement systems must cover the
range of at least 20 hertz (Hz) to 20 kilohertz (kHz); The SFV measurement systems must be
designed to have omnidirectional sensitivity and so that the broadband received level of all pile

driving and drilling activities exceeds the system noise floor by at least 10 dB. The dynamic
range of the SFV measurement system must be sufficient such that at each location, and the
signals avoid poor signal-to-noise ratios for low amplitude signals and avoid clipping,
nonlinearity, and saturation for high amplitude signals.
(ix) All hydrophones used in SFV measurements systems are required to have
undergone a full system, traceable laboratory calibration conforming to International
Electrotechnical Commission (IEC) 60565, or an equivalent standard procedure, from a factory
or accredited source to ensure the hydrophone receives accurate sound levels, at a date not to
exceed 2 years before deployment. Additional in situ calibration checks using a pistonphone are
required to be performed before and after each hydrophone deployment. If the measurement
system employs filters via hardware or software (e.g., high-pass, low-pass, etc.), which is not
already accounted for by the calibration, the filter performance (i.e., the filter’s frequency
response) must be known, reported, and the data corrected before analysis.
(x) LOA Holder must be prepared with additional equipment (hydrophones, recording
devices, hydrophone calibrators, cables, batteries, etc.), which exceeds the amount of equipment
necessary to perform the measurements, such that technical issues can be mitigated before
measurement.
(xi) LOA Holder must submit interim reports within 48 hours after each foundation is
measured with Thorough SFV (§ 217.325(10) for interim and final reporting requirements).
(xii) If any of the interim Thorough SFV reports submitted indicate that SFV
measurements exceed the modeled distances to Level A harassment and Level B harassment
thresholds assuming 10-dB attenuation, then LOA Holder must implement additional measures
on all subsequent foundations to ensure the measured Level A and Level B harassment isopleths
do not exceed those modeled for foundation installation, assuming 10dB attenuation. LOA
Holder must also increase clearance and shutdown zone sizes to those identified by NMFS until
SFV measurements on at least three additional foundations demonstrate acoustic distances to

harassment thresholds meet or are less than those modeled assuming 10-dB of attenuation. For
every 1,500 m that a marine mammal clearance or shutdown zone is expanded, additional PSOs
must be deployed from additional platforms/vessels to ensure adequate and complete
monitoring of the expanded shutdown and/or clearance zone; LOA Holder must optimize the
noise attenuation systems (e.g., ensure hose maintenance, pressure testing, etc.) to, at least, meet
noise levels modeled, assuming 10-dB attenuation, within three piles or else foundation
installation activities must cease until NMFS and LOA Holder can evaluate the situation and
ensure future piles will not exceed noise levels modeled assuming 10-dB attenuation.
(xiii) If SFV measurements collected during installation of foundation piles indicate
ranges to the isopleths, corresponding to Level A harassment and Level B harassment
thresholds, are greater than the ranges predicted by modeling (assuming 10 dB attenuation),
LOA Holder must implement additional noise mitigation measures prior to installing the next
foundation. Additional acoustic measurements must be taken after each modification.
(xiv) If, after additional measurements conducted pursuant to requirements of paragraph
(c)(15)(i) and (ii) of this section, acoustic measurements indicate that ranges to isopleths
corresponding to the Level A harassment and Level B harassment thresholds are less than the
ranges predicted by modeling (assuming 10-dB attenuation), LOA Holder may request to
NMFS Office of Protected Resources a modification of the clearance and shutdown zones. For
NMFS Office of Protected Resources to consider a modification request for reduced zone sizes,
LOA Holder must have conducted SFV measurements on an additional three foundations and
ensure that subsequent foundations would be installed under conditions that are predicted to
produce smaller harassment zones than those modeled assuming 10-dB of attenuation.
(xiv) LOA Holder must conduct SFV measurements during turbine operations to
estimate turbine operational source levels and transmission loss rates, in accordance with a
NMFS-approved SFV Plan.

(d) UXO/MEC detonations. The following requirements apply to Unexploded Ordnances
and Munitions and Explosives of Concern (UXO/MEC) detonations:
(1) Upon encountering a UXO/MEC, LOA Holder must only resort to high-order
removal (i.e., detonation) if all other means of removal are impracticable (i.e., As Low As
Reasonably Practicable (ALARP) risk mitigation procedure)) and this determination must be
documented and submitted to NMFS;
(i) LOA Holder may detonate a maximum of 10 UXO/MECs, of varying sizes but no
larger than 1,000 pounds (lbs; 454 kilograms (kg)) charge weight (i.e., E12), over the effective
period of this rulemaking and LOA(s);
(ii) LOA Holder must provide NMFS Office of Protected Resources with notification of
planned UXO/MEC detonation as soon as possible but at least 48 hours prior to the planned
detonation, unless this 48-hour notification would create delays to the detonation that would
result in imminent risk to human life or safety.
(2) UXO/MEC detonations must not occur from December 1 through May 31, annually;
however, LOA Holder may detonate a UXO/MEC in December or May with NMFS’ approval
on a case-by-case basis;
(3) UXO/MEC detonations must only occur during daylight hours (1 hour after civil
sunrise through 1.5 hours prior to civil sunset);
(4) No more than one detonation can occur within a 24-hour period;
(5) LOA Holder must deploy dual noise abatement systems during all UXO/MEC
detonations and comply with the following requirements related to noise abatement:
(i) A single bubble curtain must not be used;
(ii) A big double bubble curtain may be used without being paired with another noise
attenuation device;
(iii) The bubble curtain(s) must distribute air bubbles using an air flow rate of at least
0.5 m3/(min*m). The bubble curtain(s) must surround 100 percent of the UXO/MEC detonation

perimeter throughout the full depth of the water column. In the unforeseen event of a single
compressor malfunction, the offshore personnel operating the bubble curtain(s) must make
appropriate adjustments to the air supply and operating pressure such that the maximum
possible noise attenuation performance of the bubble curtain(s) is achieved;
(iv) The lowest bubble ring must be in contact with the seafloor for the full
circumference of the ring, and the weights attached to the bottom ring must ensure 100-percent
seafloor contact;
(v) No parts of the ring or other objects may prevent full seafloor contact;
(vi) Construction contractors must train personnel in the proper balancing of airflow to
the ring. Construction contractors must submit an inspection/performance report for approval by
LOA Holder within 72 hours following the performance test. LOA Holder must then submit
that report to NMFS Office of Protected Resources;
(vii) Corrections to the bubble ring(s) to meet the performance standards in this
paragraph (d)(5) must occur prior to UXO/MEC detonations. If LOA Holder uses a noise
mitigation device in addition to the bubble curtain, LOA Holder must maintain similar quality
control measures as described in this paragraph (d)(5); and
(viii) LOA Holder must inspect and carry out appropriate maintenance on the noise
attenuation system prior to every foundation installation event (i.e., for each pile driven
foundation) and UXO/MEC detonation and prepare and submit a NAS inspection/performance
report to NMFS Office of Protected Resources. For activities which Thorough SFV is carried
out, this report must be submitted as soon as it is available, but no later than when the interim
SFV report is submitted for the respective pile.
(6) LOA Holder must conduct SFV during all UXO/MEC detonations at a minimum of
three locations (at two water depths at each location) from each detonation in a direction toward
deeper water in accordance with the following requirements:

(i) LOA Holder must empirically determine source levels (peak and cumulative sound
exposure level), the ranges to the isopleths corresponding to the Level A harassment and Level
B harassment thresholds in meters, and the transmission loss coefficient(s). LOA Holder may
estimate ranges to the Level A harassment and Level B harassment isopleths by extrapolating
from in-situ measurements conducted at several distances from the detonation location
monitored.
(ii) The SFV measurement systems must have a sensitivity appropriate for the expected
sound levels from detonations received at the nominal ranges throughout the detonation; the
frequency range of the SFV measurement systems must cover the range of at least 20 Hz to 20
kHz; and the SFV measurement systems will be designed to have omnidirectional sensitivity
and will be designed so that the predicted broadband received level of all UXO/MEC
detonations exceeds the system noise floor by at least 10 dB. The dynamic range of the SFV
measurement systems must be sufficient such that at each location, the signals avoid poor
signal-to-noise ratios for low amplitude signals and the signals avoid clipping, nonlinearity, and
saturation for high amplitude signals.
(iii) All hydrophones used in SFV measurements systems are required to have
undergone a full system, traceable laboratory calibration conforming to IEC 60565, or an
equivalent standard procedure, from a factory or accredited source to ensure the hydrophone
receives accurate sound levels, at a date not to exceed 2 years before deployment. Additional in
situ calibration checks using a pistonphone are required to be performed before and after each
hydrophone deployment. If the measurement system employs filters via hardware or software
(e.g., high-pass, low-pass, etc.), which is not already accounted for by the calibration, the filter
performance (i.e., the filter’s frequency response) must be known, reported, and the data
corrected before analysis.
(iv) LOA Holder must be prepared with additional equipment (hydrophones, recording
devices, hydrophone calibrators, cables, batteries, etc.), which exceeds the amount of equipment

necessary to perform the measurements, such that technical issues can be mitigated before
measurement.
(v) LOA Holder must submit interim reports within 48 hours after each UXO/MEC
detonation is measured (see § 217.325(f)(10) for interim and final reporting requirements).
(vi) If SFV measurements collected during UXO/MEC detonation indicate ranges to the
isopleths, corresponding to Level A harassment and Level B harassment thresholds, are greater
than the ranges predicted by modeling (assuming 10 dB attenuation), LOA Holder must
implement additional noise mitigation measures prior to the next UXO/MEC detonation.
Additional acoustic measurements must be taken after each modification. LOA Holder must
also increase the clearance zone size to reflect the results of SFV in collaboration with NMFS
Office of Protected Resources. Use of the expanded clearance zone must continue for all
additional detonations until LOA Holder requests and receives concurrence from NMFS Office
of Protected Resources to revert to the original clearance zone. LOA Holder must provide
written notification to NMFS Office of Protected Resources of the changes planned for the next
detonation within 24 hours of implementation.
(vii) LOA Holder must optimize the noise attenuation systems (e.g., ensure hose
maintenance, pressure testing, etc.) to, at least, meet noise levels modeled, assuming 10-dB
attenuation, UXO/MEC detonation activities must cease until NMFS and LOA Holder can
evaluate the situation and ensure future detonations will not exceed noise levels modeled
assuming 10-dB attenuation.
(viii) LOA Holder must identify one or more additional, modified, and/or alternative
noise attenuation measures or other change to the detonation plans (included in the SFV Plan)
that is expected to reduce sound levels to the modeled distances. These measures must be
implemented for the next detonation.
(7) LOA Holder must establish and implement clearance zones for UXO/MEC
detonation using both visual and acoustic monitoring, as described in the LOA;

(8) At least six on-duty PSOs must be actively observing marine mammals before,
during, and after any UXO/MEC detonation. At least three on-duty PSOs must be stationed and
observing on a vessel as close as safely possible to the detonation site and, in addition, at least
three on-duty PSOs must be stationed on an additional PSO-dedicated vessel or aerial platform.
Concurrently, at least one acoustic monitoring PSO (i.e., passive acoustic monitoring (PAM)
operator) must be actively monitoring for marine mammals with PAM before, during, and after
detonation;
(i) Clearance zones must be increased to reflect the results of SFV. For every 1,500 m
that a clearance zone is expanded, additional PSOs must be deployed from additional
platforms/vessels to ensure adequate and complete monitoring of the expanded zone.
(ii) [Reserved]
(9) If the clearance zone is larger than 2 km (based on charge weight), LOA Holder must
deploy an additional PSO-dedicated vessel or aircraft with at least three on-duty PSOs stationed
on it and actively observing for marine mammals. If the clearance zone is larger than 5 km
(based on charge weight), an aerial platform must be used unless LOA Holder is unable to
secure an aerial platform(s) with the appropriately trained pilots and PSOs. In such a case, the
LOA Holder must submit an alternative monitoring plan at least 90 days before any UXO/MEC
detonation that would describe how they would effectively monitor clearance zones beyond 5
km, including an explanation of additional vessels/platforms and PSO deployments. This plan
must be approved by NMFS before any UXO/MEC detonation may occur;
(i) If an aircraft is used, two on-duty PSOs must be used and located at the appropriate
vantage point on the aircraft. These additional PSOs would maintain watch during the same
time period as the PSOs on the primary monitoring vessel.
(10) At least one PAM operator must review data from at least 24 hours prior to a
detonation and actively monitor hydrophones for 60 minutes prior to detonation. All clearance
zones must be acoustically confirmed to be free of marine mammals for 60 minutes prior to

commencing a detonation. PAM operators will continue to monitor for marine mammals at least
30 minutes after a detonation;
(11) All clearance zones must be visually confirmed to be free of marine mammals for
30 minutes before a detonation can occur. All on-duty PSOs must also maintain watch for 30
minutes after the detonation event;
(12) If a marine mammal is observed entering or within the relevant clearance zone prior
to the initiation of a detonation, detonation must be delayed and must not begin until either the
marine mammal(s) has voluntarily left the specific clearance zones and have been visually and
acoustically confirmed beyond that clearance zone, or, when specific time periods have elapsed
with no further sightings or acoustic detections. The specific time periods are 15 minutes for
small odontocetes and pinnipeds and 30 minutes for all other marine mammal species;
(13) For North Atlantic right whales, any visual observation or acoustic detection must
trigger a delay to the detonation of a UXO/MEC. Any large whale sighting by a PSO or
detected by a PAM operator that cannot be identified by species must be treated as if it were a
North Atlantic right whale; and
(14) A pressure transducer must be used to monitor pressure levels during all
UXO/MEC detonations.
(e) HRG surveys. The following requirements apply to HRG surveys operating subbottom profilers (SBPs) (i.e., boomers, sparkers):
(1) SBPs (hereinafter referred to as “acoustic sources”) must be deactivated when not
acquiring data or preparing to acquire data, except as necessary for testing. Acoustic sources
must be used at the lowest practicable source level to meet the survey objective, when in use,
and must be turned off when they are not necessary for the survey;
(2) LOA Holder is required to have at least one PSO on active duty per HRG vessel
during HRG surveys that are conducted during daylight hours (i.e., from 30 minutes prior to

civil sunrise through 30 minutes following civil sunset) and at least two PSOs on active duty per
vessel during HRG surveys that are conducted during nighttime hours;
(3) LOA Holder is required to ramp-up SBPs prior to commencing full power, unless the
equipment operates on a binary on/off switch, and ensure visual clearance zones are fully visible
(e.g., not obscured by darkness, rain, fog, etc.) and clear of marine mammals, as determined by
the Lead PSO, for at least 30 minutes immediately prior to the initiation of survey activities
using acoustic sources specified in the LOA;
(4) Ramp-ups must be scheduled so as to minimize the time spent with the source
activated. Prior to a ramp-up procedure starting or activating acoustic sources, the acoustic
source operator (operator) must notify a designated PSO of the planned start of ramp-up as
agreed upon with the Lead PSO. The notification time should not be less than 60 minutes prior
to the planned ramp-up or activation in order to allow the PSOs time to monitor the clearance
zone(s) for 30 minutes prior to the initiation of ramp-up or activation (pre-start clearance).
During this 30-minute pre-start clearance period, the entire applicable clearance zones must be
visible. Ramp-up may occur at times of poor visibility, including nighttime, only if appropriate
visual monitoring has occurred with no detections of marine mammals in the 30 minutes prior
to beginning ramp-up;
(i) A PSO conducting pre-start clearance observations must be notified again
immediately prior to reinitiating ramp-up procedures and the operator must receive
confirmation from the PSO to proceed.
(ii) [Reserved]
(5) Prior to starting the survey and after receiving confirmation from the PSOs that the
clearance zone is clear of any marine mammals, LOA Holder is required to ramp-up acoustic
sources to half power for 5 minutes prior to commencing full power, unless the source operates
on a binary on/off switch (in which case ramp-up is not required). LOA Holder must also ensure
visual clearance zones are fully visible (e.g., not obscured by darkness, rain, fog, etc.) and clear

of marine mammals, as determined by the Lead PSO, for at least 30 minutes immediately prior
to the initiation of survey activities using acoustic sources; Ramp-up and activation must be
delayed if a marine mammal(s) enters its respective shutdown zone. Ramp-up and activation
may only be reinitiated if the animal(s) has been observed exiting its respective shutdown zone
or until 15 minutes for small odontocetes and pinnipeds, and 30 minutes for all other species,
has elapsed with no further sightings;
(6) LOA Holder must establish and implement clearance and shutdown zones for HRG
surveys using visual monitoring; LOA Holder must implement a 30-minute clearance period of
the clearance zones immediately prior to the commencing of the survey or when there is more
than a 30 minute break in survey activities or PSO monitoring. A clearance period is a period
when no marine mammals are detected in the relevant zone;
(7) If a marine mammal is observed within a clearance zone during the clearance period,
ramp-up or acoustic surveys may not begin until the animal(s) has been observed voluntarily
exiting its respective clearance zone or until a specific time period has elapsed with no further
sighting. The specific time period is 15 minutes for small odontocetes and pinnipeds, and 30
minutes for all other species;
(8) Any large whale sighted by a PSO within 1 km of the acoustic source(s) that cannot
be identified by species must be treated as if it were a North Atlantic right whale and LOA
Holder must apply the mitigation measure applicable to this species;
(9) In any case when the clearance process has begun in conditions with good visibility,
including via the use of night vision equipment (infrared (IR)/thermal camera), and the Lead
PSO has determined that the clearance zones are clear of marine mammals, survey operations
may commence (i.e., no delay is required) despite periods of inclement weather and/or loss of
daylight.
(10) Once the survey has commenced, LOA Holder must shut down acoustic sources if a
marine mammal enters a respective shutdown zone, except in cases when the shutdown zones

become obscured for brief periods due to inclement weather, survey operations may continue
(i.e., no shutdown is required) so long as no marine mammals have been detected. The
shutdown requirement does not apply to small delphinids of the following genera: Delphinus,
Stenella, Lagenorhynchus, and Tursiops. If there is uncertainty regarding the identification of a
marine mammal species (i.e., whether the observed marine mammal belongs to one of the
delphinid genera for which shutdown is waived), the PSOs must use their best professional
judgment in making the decision to call for a shutdown. Shutdown is required if a delphinid that
belongs to a genus other than those specified in this paragraph (e)(10) is detected in the
shutdown zone;
(11) If an acoustic source has been shut down due to the presence of a marine mammal,
the use of an acoustic source may not commence or resume until the animal(s) has been
confirmed to have left the Level B harassment zone or until a full 15 minutes for small
odontocetes and pinnipeds and 30 minutes for all other marine mammals have elapsed with no
further sighting;
(12) LOA Holder must immediately shutdown any acoustic source if a marine mammal
is sighted entering or within its respective shutdown zones. If there is uncertainty regarding the
identification of a marine mammal species (i.e., whether the observed marine mammal belongs
to one of the delphinid genera for which shutdown is waived), the PSOs must use their best
professional judgment in making the decision to call for a shutdown. Shutdown is required if a
delphinid that belongs to a genus other than those specified in paragraph (e)(10) of this section
is detected in the shutdown zone;
(13) If an acoustic source is shut down for a period longer than 30 minutes, all clearance
and ramp-up procedures must be initiated. If an acoustic source is shut down for reasons other
than mitigation (e.g., mechanical difficulty) for less than 30 minutes, acoustic sources may be
activated again without ramp-up only if PSOs have maintained constant observation and no

additional detections of any marine mammal occurred within the respective shutdown zones;
and
(14) If multiple HRG vessels are operating concurrently, any observations of marine
mammals must be communicated to PSOs on all nearby survey vessels.
(f) Fisheries monitoring surveys. The following measures apply to fishery monitoring
surveys:
(1) All captains and crew conducting fishery surveys must be trained in marine mammal
detection and identification. Marine mammal monitoring will be conducted by the captain
and/or a member of the scientific crew before within 1 nautical mile (nmi) (1.85 km; 1.2 mi)
and 15 minutes prior to deploying gear), during, and for 15 minutes after haul back;
(2) Survey gear will be deployed as soon as possible once the vessel arrives on station.
Gear must not be deployed if there is a risk of interaction with marine mammals. Gear may be
deployed after 15 minutes of no marine mammal sightings within 1 nmi (1.85 km; 1.2 mi) of the
sampling station;
(3) LOA Holder and/or its cooperating institutions, contracted vessels, or commerciallyhired captains must implement the following “move-on” rule: If marine mammals are sighted
within 1 nmi (1.2 mi) of the planned location and 15 minutes before gear deployment, then
LOA Holder and/or its cooperating institutions, contracted vessels, or commercially-hired
captains, as appropriate, must move the vessel away from the marine mammal to a different
section of the sampling area. If, after moving on, marine mammals are still visible from the
vessel, LOA Holder and its cooperating institutions, contracted vessels, or commercially-hired
captains must move again or skip the station;
(4) If a marine mammal is at risk of interacting with deployed gear, all gear must be
immediately removed from the water. If marine mammals are sighted before the gear is fully
removed from the water, the vessel must slow its speed and maneuver the vessel away from the
animals to minimize potential interactions with the observed animal;

(5) LOA Holder must maintain visual marine mammal monitoring effort during the
entire period of time that gear is in the water (i.e., throughout gear deployment, fishing, and
retrieval). If marine mammals are sighted before the gear is fully removed from the water, LOA
Holder must take the most appropriate action to avoid marine mammal interaction;
(6) All fisheries monitoring gear must be fully cleaned and repaired (if damaged) before
each use/deployment;
(7) LOA Holder’s fixed gear must comply with the Atlantic Large Whale Take
Reduction Plan regulations at 50 CFR 229.32 during fisheries monitoring surveys;
(8) Trawl tows will be limited to a maximum of a 20-minute trawl time and must not
exceed 3.0 kn (3.45 mph);
(9) All gear must be emptied as close to the deck/sorting area and as quickly as possible
after retrieval;
(10) During trawl surveys, vessel crew must open the codend of the trawl net close to
the deck in order to avoid injury to animals that may be caught in the gear;
(11) During any survey that uses vertical lines, buoy lines will be weighted and will not
float at the surface of the water and all groundlines will consist of sinking line. All groundlines
must be composed entirely of sinking line. Buoy lines must utilize weak links. Weak links must
break cleanly leaving behind the bitter end of the line. The bitter end of the line must be free of
any knots when the weak link breaks. Splices are not considered to be knots. The attachment of
buoys, toggles, or other floatation devices to groundlines is prohibited;
(12) All in-water survey gear, including buoys, must be properly labeled with the
scientific permit number or identification as LOA Holder- related research gear. All labels and
markings on the gear, buoys, and buoy lines must also be compliant with the applicable
regulations, and all buoy markings must comply with instructions received by the NOAA
GARFO Protected Resources Division;

(13) All survey gear must be removed from the water whenever not in active survey use
(i.e., no wet storage);
(14) All reasonable efforts, that do not compromise human safety, must be undertaken to
recover gear; and
(15) All lost gear associated with the fishery surveys must be reported to NOAA
GARFO Protected Resources Division (nmfs.gar.incidental-take@noaa.gov) within 24 hours of
the documented time of missing or lost gear. This report must include information on any
markings on the gear and any efforts undertaken or planned to recover the gear.
§ 217.325 Monitoring and reporting requirements.
LOA Holder must implement the following monitoring and reporting requirements when
conducting the specified activities:
(a) Protected species observer (PSO) and passive acoustic monitoring (PAM) operator
qualifications. LOA Holder must implement the following measures applicable to PSOs and
PAM operators:
(1) LOA Holder must use independent, NMFS-approved PSOs and PAM operators
meaning that the PSOs and PAM operators must be employed by a third-party observer
provider, must have no tasks other than to conduct observational effort, collect data, and
communicate with and instruct relevant crew with regard to the presence of protected species
and mitigation requirements;
(2) All PSOs and PAM operators must have successfully attained a bachelor’s degree
from an accredited college or university with a major in one of the natural sciences, a minimum
of 30 semester hours or equivalent in the biological sciences, and at least one undergraduate
course in math or statistics. The educational requirements may be waived if the PSO or PAM
operator has acquired the relevant skills through a suitable amount of alternate experience.
Requests for such a waiver must be submitted to NMFS Office of Protected Resources and must

include written justification containing alternative experience. Alternate experience that may be
considered includes but is not limited to: previous work experience conducting academic,
commercial, or government sponsored marine mammal visual and/or acoustic surveys; or
previous work experience as a PSO/PAM operator. All PSO’s and PAM operators should
demonstrate good standing and consistently good performance of all assigned duties;
(3) All PSOs and PAM operators must successfully complete a required training course
within the last 5 years, including obtaining a certificate of course completion;
(4) PSOs must have visual acuity in both eyes (with correction of vision being
permissible) sufficient enough to discern moving targets on the water's surface with the ability
to estimate the target size and distance (binocular use is allowable); ability to conduct field
observations and collect data according to the assigned protocols; sufficient training,
orientation, or experience with the construction operation to provide for personal safety during
observations; writing skills sufficient to document observations, including but not limited to, the
number and species of marine mammals observed, the dates and times of when in-water
construction activities were conducted, the dates and time when in-water construction activities
were suspended to avoid potential incidental take of marine mammals from construction noise
within a defined shutdown zone, and marine mammal behavior; and the ability to communicate
orally, by radio, or in-person, with project personnel to provide real-time information on marine
mammals observed in the area;
(5) PSOs and PAM operators are responsible for obtaining NMFS’ approval. NMFS
may approve PSOs and PAM operators as conditional or unconditional. A conditionallyapproved PSO or PAM operator may be one who has completed training in the last 5 years but
has not yet attained the requisite field experience. An unconditionally approved PSO or PAM
operator is one who has completed training within the last 5 years and attained the necessary
experience (i.e., demonstrate experience with monitoring for marine mammals at clearance and
shutdown zone sizes similar to those produced during the respective activity). Lead PSO(s) and

Lead PAM operator(s) must be unconditionally approved and have a minimum of 90 days in a
northwestern Atlantic Ocean offshore environment performing the role (either visual or
acoustic), with the conclusion of the most recent relevant experience not more than 18 months
previous. A conditionally approved PSO or PAM operator must be paired with an
unconditionally approved PSO or PAM operator;
(i) PSOs for HRG surveys may be unconditionally or conditionally approved. PSOs and
PAM operators for foundation installation and UXO/MEC detonation must be unconditionally
approved;
(ii) LOA Holder must submit NMFS previously approved PSOs and PAM operators to
NMFS Office of Protected Resources for review and confirmation of their approval for specific
roles at least 30 days prior to commencement of the activities requiring PSOs/PAM operators or
15 days prior to when new PSOs/PAM operators are required after activities have commenced;
(iii) For prospective PSOs and PAM operators not previously approved, or for PSOs and
PAM operators whose approval is not current, LOA Holder must submit resumes for approval
at least 60 days prior to PSO and PAM operator use. Resumes must include information related
to relevant education, experience, and training, including dates, duration, location, and
description of prior PSO or PAM operator experience. Resumes must be accompanied by
relevant documentation of successful completion of necessary training and include which
specific roles and activities the PSOs/PAM operators are being requested for. PAM operator
experience must also include the information described in paragraph (a)(5)(iv) of this section;
(iv) PAM operators are responsible for obtaining NMFS approval. To be approved as a
PAM operator, the person must meet the following qualifications: The PAM operator must
demonstrate that they have prior large whale PAM experience with real-time acoustic detection
systems and/or have completed specialized training for operating PAM systems that will be
used for the Project; PAM operators must demonstrate that they are able to detect and identify
Atlantic Ocean marine mammals sounds, in particular: North Atlantic right whale sounds,

humpback whale sounds, and that they are able to deconflict humpback whale sounds from
similar North Atlantic right whale sounds, and other co-occurring species’ sounds in the area
including sperm whales; must be able to distinguish between whether a marine mammal or
other species sound is detected, possibly detected, or not detected and similar terminology must
be used across companies/projects; where localization of sounds or deriving bearings and
distance are possible, the PAM operators must have demonstrated experience in the localization
of sounds or deriving bearings and distance; PAM operators must be independent observers
(i.e., not construction personnel); PAM operators must demonstrate experience with relevant
acoustic software and equipment; PAM operators must have the qualifications and relevant
experience/training to safely deploy and retrieve equipment and program the software, as
necessary; PAM operators must be able to test software and hardware functionality prior to
operation; and PAM operators must have evaluated their acoustic detection software using the
PAM Atlantic baleen whale annotated data set available at National Centers for Environmental
Information (NCEI) and provide evaluation/performance metric;
(6) All PSOs must be trained in northwestern Atlantic Ocean marine mammal
identification and behaviors and must be able to conduct field observations and collect data
according to assigned protocols. Additionally, PSOs must have the ability to work with all
required and relevant software and equipment necessary during observations (as described in
paragraphs (b)(5) and (6) of this section);
(7) At least one on-duty PSO and PAM operator, where applicable, for each activity
(i.e., foundation installation, UXO/MEC detonation activities, and HRG surveys) must be
designated as the Lead PSO. The Lead PSO must be unconditionally approved; and
(8) PSOs may work as PAM operators and vice versa, pending NMFS-approval;
however, they may only perform one role at any one time and must not exceed work time
restrictions, which will be tallied cumulatively.

(b) General PSO and PAM operator requirements. The following measures apply to
PSOs and PAM operators and must be implemented by LOA Holder:
(1) PSOs must monitor for marine mammals prior to, during, and following pile driving,
drilling, UXO/MEC detonation activities, and HRG surveys that use sub- bottom profilers (with
specific monitoring durations and needs described in paragraphs (c) through (f) of this section,
respectively). Monitoring must be done while free from distractions and in a consistent,
systematic, and diligent manner;
(2) PAM operator(s) must acoustically monitor for marine mammals prior to, during,
and following all pile driving, drilling, and UXO/MEC detonation activities. PAM operators
may be located on a vessel or remotely on-shore but must have the appropriate equipment (i.e.,
computer station equipped with a data collection software system available wherever they are
stationed) and be in real-time communication with PSOs and transiting vessel captains;
(3) All PSOs must be located at the best vantage point(s) on any platform, as determined
by the Lead PSO, in order to obtain 360-degree visual coverage of the entire clearance and
shutdown zones around the activity area, and as much of the Level B harassment zone as
possible, PAM operators may be located on a vessel or remotely on-shore. The PAM operator(s)
must assist PSOs in ensuring full coverage of the clearance and shutdown zones;
(4) All on-duty visual PSOs must remain in real-time contact with the on-duty PAM
operator(s). PAM operators must immediately communicate all acoustic detections of marine
mammals to PSOs, including any determination regarding species identification, distance, and
bearing (where relevant) relative to the pile being driven and the degree of confidence (e.g.,
detected, possibly detected, not detected) in the determination. All on-duty Lead PSOs and
PAM operator(s) must remain in contact with the on-duty construction personnel responsible for
implementing mitigations (e.g., delay to pile driving or UXO/MEC detonation) to ensure
communication on marine mammal observations can easily, quickly, and consistently occur
between all on-duty PSOs, PAM operator(s), and on-water Project personnel.

(i) The on-duty PAM operator(s) must inform the on-duty Lead PSO(s) of animal
detections approaching or within applicable ranges of interest to the activity occurring via the
data collection software system, (e.g., Mysticetus or similar system) who must be responsible
for requesting that the designated crewmember implement the necessary mitigation procedures
(i.e., delay, shutdown); and
(ii) Any visual observations of marine mammals by any Project personnel must be
communicated immediately to on-duty PSOs and vessel captains associated with other Project
vessels to increase situational awareness.
(5) PSOs must use high magnification (25x) binoculars, standard handheld (7x)
binoculars, and the naked eye to search continuously for marine mammals. During pile driving
and drilling, at least the PSOs on the pile driving and drilling platform(s) and any dedicated
PSO vessel that may be used must be equipped with functional Big Eye binoculars (e.g., 25 x
150; 2.7 view angle; individual ocular focus; height control). These must be pedestal mounted
on the deck at the best vantage point that provides for optimal sea surface observation and PSO
safety. A minimum of three on-duty PSOs must be active on a dedicated PSO vessel. PAM
operators must have the appropriate equipment (i.e., a computer station equipped with a data
collection software system available wherever they are stationed) in accordance with a NMFSapproved PAM Plan;
(6) During all acoustic monitoring periods during the Project, PAM operators must use
PAM systems approved by NMFS;
(7) During periods of low visibility (e.g., darkness, rain, fog, poor weather conditions,
etc.), PSOs must use alternative technology (e.g., infrared or thermal cameras) to monitor the
clearance and shutdown zones as approved by NMFS;
(8) PSOs and PAM operators must not exceed 4 consecutive watch hours on duty at any
time, must have a 2-hour (minimum) break between watches, and must not exceed a combined
watch schedule of more than 12 hours in a 24-hour period;

(9) Any PSO or PAM operator has the authority to call for a delay or shutdown of
project activities;
(10) PSOs must remain in real-time contact with the PAM operators and construction
personnel responsible for implementing mitigation (e.g., delay to pile driving or UXO/MEC
detonation) to ensure communication on marine mammal observations can easily, quickly, and
consistently occur between all on-duty PSOs, PAM operator(s), and on-water Project personnel;
and
(11) LOA Holder is required to use available sources of information on North Atlantic
right whale presence to aid in monitoring efforts. These include daily monitoring of the Right
Whale Sightings Advisory System, consulting of the WhaleAlert app, and monitoring of the
Coast Guard’s VHF Channel 16 throughout the day to receive notifications of any sightings and
information associated with any DMA, to plan construction activities and vessel routes, if
practicable, to minimize the potential for co-occurrence with North Atlantic right whales.
(c) PSO and PAM operator requirements during WTG and ESP foundation installation.
The following measures apply to PSOs and PAM operators during WTG and ESP foundation
installation and must be implemented by LOA Holder:
(1) PSOs and PAM operator(s) must monitor for marine mammals 60 minutes prior to,
during, and 30 minutes following all pile-driving and drilling. If PSOs cannot visually monitor
the minimum visibility zone prior to pile driving and drilling at all times using the equipment
described in paragraphs (b)(5) and (7) of this section, pile driving and drilling operations must
not commence or must shutdown if they are currently active;
(2) All PSOs and PAM operators must begin monitoring 60 minutes prior to pile driving
and drilling, during, and for 30 minutes after the activity. Pile driving and drilling must only
commence when the minimum visibility zone is fully visible (e.g., not obscured by darkness,
rain, fog, etc.) and the clearance zones are clear of marine mammals for at least 30 minutes, as
determined by the Lead PSO, immediately prior to the initiation of pile driving or drilling. PAM

operators must assist the visual PSOs in monitoring by conducting PAM activities 60 minutes
prior to any pile driving or drilling, during, and after for 30 minutes for the appropriate size
PAM clearance zone (dependent on season). The entire minimum visibility zone must be clear
for at least 30 minutes, with no marine mammal detections within the visual or PAM clearance
zones prior to the start of pile driving or drilling;
(3) LOA Holder must conduct PAM for at least 24 hours immediately prior to pile
driving and drilling activities, The PAM operator must review all detections from the previous
24-hour period immediately prior to pile driving or drilling.
(4) During use of any real-time PAM system, at least one PAM operator must be
designated to monitor each system by viewing data or data products that would be streamed in
real-time or in near real-time to a computer workstation and monitor;
(5) The PAM operator must inform the Lead PSO(s) on duty of animal detections
approaching or within applicable ranges of interest to the pile driving activity via the data
collection software system (i.e., Mysticetus or similar system) who will be responsible for
requesting that the designated crewmember implement the necessary mitigation procedures (i.e.,
delay or shutdown);
(6) All monitoring and reporting measures required for or applicable to jacket
foundations are required for bottom-frame foundations that utilize pile foundations;
(7) LOA Holder must prepare and submit a Marine Mammal Monitoring Plan to NMFS
Office of Protected Resources for review and approval at least 180 days before the planned start
of any pile driving or drilling and abide by the plan if approved. LOA Holder must obtain both
NMFS Office of Protected Resources and NMFS Greater Atlantic Regional Fisheries Office
Protected Resources Division’s concurrence with this plan prior to the start of any pile driving
or drilling. The plan must include final foundation project design (e.g., number and type of
piles, hammer type, noise abatement systems, anticipated start date, etc.) and all information

related to PAM and PSO monitoring protocols for foundation installation activities. No
foundation pile installation can occur without NMFS’ approval of the plan;
(8) LOA Holder must submit an SFV plan to NMFS Office of Protected Resources for
review and approval at least 180 days prior to planned start of foundation installation activities
and abide by the plan if approved. At minimum, the SFV Plan must describe how LOA Holder
would ensure that the required foundation installation sites selected for SFV measurements are
representative of the rest of the installation sites such that future pile installation events are
anticipated to produce similar sound levels to those piles measured. In the case that these
sites/scenarios are not determined to be representative of all other pile installation sites, LOA
Holder must include information in the SFV Plan on how additional sites/scenarios would be
selected for SFV measurements. This SFV Plan must also include methodology for collecting,
analyzing, and preparing SFV measurement data for submission to NMFS Office of Protected
Resources and describe how the effectiveness of the noise attenuation methodology would be
evaluated based on the results. SFV for pile driving and drilling must not occur until NMFS
approves the SFV Plan for this activity;
(9) LOA Holder must submit a Passive Acoustic Monitoring Plan (PAM Plan) to NMFS
Office of Protected Resources for review and approval at least 180 days prior to the planned
start of foundation installation activities and abide by the plan if approved. The PAM Plan must
include a description of all proposed PAM equipment, address how the proposed passive
acoustic monitoring must follow standardized measurement, processing methods, reporting
metrics, and metadata standards for offshore wind. The plan must describe all proposed PAM
equipment, procedures, and protocols including proof that vocalizing North Atlantic right
whales will be detected within the PAM Monitoring Zone. No pile installation can occur if LOA
Holder’s PAM Plan does not receive approval from NMFS Office of Protected Resources and
NMFS GARFO Protected Resources Division; and

(10) LOA Holder must submit a Nighttime Monitoring Plan for foundation installation if
LOA Holder intends to pile drive or drill outside the daily restriction in § 217.324(c). This plan
must be submitted to NMFS Office of Protected Resources at least 180 calendar days before
foundation installation is planned to begin. This plan(s) must contain a thorough description of
how LOA Holder will monitor foundation installation activities (drilling, vibratory and impact
pile driving) and at night, including proof of the efficacy of monitoring devices (e.g., mounted
thermal/infrared camera systems, hand-held or wearable NVDs, spotlights) in detecting marine
mammals over the full extent of the required clearance and shutdown zones, including
demonstration that the full extent of the minimum visibility zones can be effectively and
reliably monitored. The plan must identify the efficacy of the technology at detecting marine
mammals and sea turtles in the clearance and shutdown zones under all the various conditions
anticipated during construction, including varying weather conditions, sea states, and in
consideration of the use of artificial lighting. If the plan does not include a full description of the
proposed technology, monitoring methodology, and data demonstrating to NMFS’ satisfaction
that marine mammals can reliably and effectively be detected within the clearance and
shutdown zones for monopiles and jacket foundations before and during foundation installation
(drilling, vibratory and impact pile driving), nighttime foundation installation must not occur;
the only exception would be if safety necessitates continuing pile installation after dark for a
foundation that was initiated 1.5 hours prior to civil sunset, in which case the Low Visibility
components of the Monitoring Plan would be implemented.
(d) PSO requirements during UXO/MEC detonations. The following measures apply to
PSOs UXO/MEC detonations and must be implemented by LOA Holder:
(1) All on-duty visual PSOs must remain in contact with the on-duty PAM operator,
who would monitor the PAM systems for acoustic detections of marine mammals in the area,
regarding any animal detection that might be approaching or found within the applicable zones
no matter where the PAM operator is stationed (e.g., onshore or on a vessel);

(2) If PSOs cannot visually monitor the clearance zone at all times using the equipment
described in paragraphs (b)(5) and (7) of this section; UXO/MEC operations must not
commence or must shutdown if they are currently active;
(3) All PSOs must begin monitoring 60 minutes prior to UXO/MEC detonation, during,
and for 30 minutes after the activity. UXO/MEC detonation must only commence when the
minimum visibility zone is fully visible (e.g., not obscured by darkness, rain, fog, etc.) and the
clearance zones are clear of marine mammals for at least 30 minutes, as determined by the Lead
PSO, immediately prior to the initiation of detonation. PAM operators must assist the visual
PSOs in monitoring by conducting PAM activities 60 minutes prior to any UXO/MEC
detonation, during, and after for 30 minutes for the appropriate size PAM clearance zone. The
entire clearance zone must be clear for at least 30 minutes, with no marine mammal detections
within the visual or PAM clearance zones prior to the initiation of detonation;
(4) For North Atlantic right whales, any visual or acoustic detection must trigger a delay
to the commencement of UXO/MEC detonation. In the event that a large whale is sighted or
acoustically detected that cannot be confirmed by species, it must be treated as if it were a North
Atlantic right whale;
(5) LOA Holder must conduct PAM for at least 24 hours immediately prior to
foundation installation and UXO/MEC detonation activities;
(6) During use of any real-time PAM system, at least one PAM operator must be
designated to monitor each system by viewing data or data products that would be streamed in
real-time or in near real-time to a computer workstation and monitor;
(7) LOA Holder must use a minimum of one PAM operator to actively monitor for
marine mammals before, during, and after UXO/MEC detonation. The PAM operator must
assist visual PSOs in ensuring full coverage of the clearance and shutdown zones. The PAM
operator must inform the Lead PSO(s) on duty of animal detections approaching or within
applicable ranges of interest to the activity occurring via the data collection software system

(i.e., Mysticetus or similar system) who will be responsible for requesting that the designated
crewmember implement the necessary mitigation procedures (i.e., delay or shutdown);
(8) PSOs and PAM operators must be on watch for a maximum of 4 consecutive hours,
followed by a break of at least 2 hours between watches, and may not exceed a combined watch
schedule of more than 12 hours in a single 24-hour period;
(9) LOA Holder must prepare and submit a Marine Mammal Monitoring Plan to NMFS
Office of Protected Resources for review and approval at least 180 days before the start of any
detonation and abide by the plan if approved. LOA Holder must obtain both NMFS Office of
Protected Resources and NMFS Greater Atlantic Regional Fisheries Office Protected Resources
Division’s concurrence with this Plan prior to the start of any UXO/MEC detonation. The plan
must include a description of how all relevant mitigation and monitoring requirements
contained in the LOA and those included as part of the action will be implemented; a pile
driving installation summary and sequence of events; a description of all monitoring equipment
and evidence (i.e., manufacturer's specifications, reports, testing) that it can be used to
effectively monitor and detect marine mammals in the identified clearance and shutdown zones
(i.e., field data demonstrating reliable and consistent ability to detect large whales at the relevant
distances in the conditions planned for use); communications and reporting details; final
UXO/MEC detonation project design (e.g., number and type of UXO/MECs, removal
method(s), charge weight(s), anticipated start date, etc.) and all information related to PAM and
PSO monitoring protocols (including number and location of PSOs) for UXO/MEC activities.
The Plan(s) must demonstrate sufficient PSO and PAM Operator staffing (in accordance with
watch shifts), PSO and PAM Operator schedules, and contingency plans for instances if
additional PSOs and PAM Operators are required including any expansion of clearance and/or
shutdown zones that may be required as a result of SFV. The plan(s) must contain a thorough
description of how LOA Holder will monitor foundation installation activities (drilling,
vibratory and impact pile driving) during reduced visibility conditions (e.g. rain, fog) and in

other low visibility conditions, including proof of the efficacy of monitoring devices (e.g.,
mounted thermal/infrared camera systems, hand-held or wearable NVDs, spotlights) in
detecting marine mammals over the full extent of the required clearance and shutdown zones,
including demonstration that the full extent of the minimum visibility zones can be effectively
and reliably monitored. The plan must identify the efficacy of the technology at detecting
marine mammals in the clearance and shutdown zones under all the various conditions
anticipated during construction, including varying weather conditions, sea states, and in
consideration of the use of artificial lighting. The plan must contain a thorough description of
how LOA Holder will monitor foundation installation activities during daytime when
unexpected changes to lighting or weather occur during pile driving that prevent visual
monitoring of the full extent of the clearance and shutdown zones. No UXO/MEC detonation
can occur without NMFS’ approval of the Plan;
(10) A Passive Acoustic Monitoring Plan (“PAM Plan”) must be submitted to NMFS
Office of Protected Resources for review and approval at least 180 days prior to the planned
start of foundation installation and prior to the start of any UXO/MEC detonation(s). The
authorization to take marine mammals would be contingent upon NMFS Office of Protected
Resources approval of the PAM Plan. The Plan must include a description of all proposed PAM
equipment and hardware, the calibration data, bandwidth capability and sensitivity of
hydrophones, and address how the proposed passive acoustic monitoring will follow
standardized measurement, processing methods, reporting metrics, and metadata standards for
offshore wind (Van Parijs et al., 2021). The Plan must describe and include all procedures,
documentation, and protocols including information (i.e., testing, reports, equipment
specifications) to support that it will be able to detect vocalizing whales within the clearance
and shutdown zones, including deployment locations, procedures, detection review
methodology, and protocols; hydrophone detection ranges with and without foundation
installation activities and data supporting those ranges; communication time between call and

detection, and data transmission rates between PAM Operator and PSOs on the pile driving
vessel; where PAM Operators will be stationed relative to hydrophones and PSOs on pile
driving vessel calling for delay/shutdowns; and a full description of all proposed software, call
detectors, and filters. The Plan must also incorporate the requirements relative to North Atlantic
right whale reporting. No UXO/MEC detonation can occur if LOA Holder’s PAM Plan does not
receive approval from NMFS Office of Protected Resources and NMFS GARFO Protected
Resources Division; and
(11) LOA Holder must submit an SFV plan to NMFS Office of Protected Resources for
review and approval at least 180 days prior to planned UXO/MEC detonation activities and
abide by the plan if approved. LOA Holder must obtain both NMFS Office of Protected
Resources and NMFS GARFO Protected Resources Division’s concurrence with this Plan prior
to the start of any UXO/MEC detonations. At minimum, the SFV Plan must include
methodology for collecting, analyzing, and preparing SFV measurement data for submission to
NMFS Office of Protected Resources and describe how the effectiveness of the noise
attenuation methodology would be evaluated based on the results. SFV for UXO/MEC
detonation must not occur until NMFS approves the SFV Plan for this activity.
(e) PSO requirements during HRG surveys. The following measures apply to PSOs
during HRG surveys using boomers, and sparkers and must be implemented by LOA Holder:
(1) Between four and six PSOs must be present on every 24-hour survey vessel and two
to three PSOs must be present on every 12-hour survey vessel;
(2) At least one PSO must be on active duty monitoring during HRG surveys conducted
during daylight (i.e., from 30 minutes prior to civil sunrise through 30 minutes following civil
sunset) and at least two PSOs must be on activity duty monitoring during HRG surveys
conducted at night;
(3) PSOs on HRG vessels must begin monitoring 30 minutes prior to activating acoustic
sources, during the use of these acoustic sources, and for 30 minutes after use of these acoustic

sources has ceased. Any observations of marine mammals must be communicated to PSOs on
all nearby survey vessels during concurrent HRG surveys; and
(4) During daylight hours when survey equipment is not operating, LOA Holder must
ensure that visual PSOs conduct, as rotation schedules allow, observations for comparison of
sighting rates and behavior with and without use of the specified acoustic sources. Off-effort
PSO monitoring must be reflected in the monthly PSO monitoring reports.
(f) Reporting. LOA Holder must comply with the following reporting measures:
(1) Prior to initiation of the specified activities, LOA Holder must demonstrate in a
report submitted to NMFS Office of Protected Resources that all required training for LOA
Holder personnel (including the vessel crews, vessel captains, PSOs, and PAM operators) has
been completed;
(2) LOA Holder must use a standardized reporting system during the effective period of
the LOA. All data collected related to the Project must be recorded using industry-standard
software that is installed on field laptops and/or tablets. Unless stated otherwise, all reports must
be submitted to NMFS Office of Protected Resources (PR.ITP.MonitoringReports@noaa.gov),
dates must be in MM/DD/YYYY format, and location information must be provided in Decimal
Degrees and with the coordinate system information (e.g., NAD83, WGS84, etc.);
(3) For all monitoring efforts and marine mammal sightings, the following information
must be collected and reported to NMFS Office of Protected Resources: Date and time that
monitored activity begins or ends; the construction activities occurring during each observation
period; the watch status (i.e., sighting made by PSO on/off effort, opportunistic, crew, alternate
vessel/platform); the PSO who sighted the animal; the time of sighting; the weather parameters
(e.g., wind speed, percent cloud cover, visibility); the water conditions (e.g., Beaufort sea state,
tide state, water depth); all marine mammal sightings, regardless of distance from the
construction activity; species (or lowest possible taxonomic level possible); the pace of the
animal(s); the estimated number of animals (minimum/maximum/high/low/best); the estimated

number of animals by cohort (e.g., adults, yearlings, juveniles, calves, group composition, etc.);
the description (i.e., as many distinguishing features as possible of each individual seen,
including length, shape, color, pattern, scars or markings, shape and size of dorsal fin, shape of
head, and blow characteristics); the description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling) and observed changes in behavior,
including an assessment of behavioral responses thought to have resulted from the specific
activity; the animal’s closest distance and bearing from the pile being driven or specified HRG
equipment and estimated time entered or spent within the Level A harassment and/or Level B
harassment zone(s); the activity at time of sighting (e.g., vibratory installation/removal, impact
pile driving, construction survey), use of any noise attenuation device(s), and specific phase of
activity (e.g., ramp-up of HRG equipment, HRG acoustic source on/off, soft-start for pile
driving, active pile driving, etc.); the marine mammal occurrence in Level A harassment or
Level B harassment zones; the description of any mitigation-related action implemented, or
mitigation-related actions called for but not implemented, in response to the sighting (e.g.,
delay, shutdown, etc.) and time and location of the action; and other human activity in the area,
and; other applicable information, as required in any LOA issued under the final rule;
(4) If a marine mammal is acoustically detected during PAM monitoring, the following
information must be recorded and reported to NMFS Office of Protected Resources: Location of
hydrophone (latitude & longitude; in Decimal Degrees) and site name; bottom depth and depth
of recording unit (in meters); recorder (model & manufacturer) and platform type (i.e., bottommounted, electric glider, etc.), and instrument ID of the hydrophone and recording platform (if
applicable); time zone for sound files and recorded date/times in data and metadata (in relation
to Universal Coordinated Time (UTC); i.e., Eastern Standard Time (EST) time zone is UTC-5);
duration of recordings (start/end dates and times; in International Organization for
Standardization (ISO) 8601 format, yyyy-mm-ddTHH:MM:SS.sssZ); deployment/retrieval
dates and times (in ISO 8601 format); recording schedule (must be continuous); hydrophone

and recorder sensitivity (in dB re 1 microPascal (μPa)); calibration curve for each recorder;
bandwidth/sampling rate (in Hz); sample bit-rate of recordings; and, detection range of
equipment for relevant frequency bands (in meters);
(5) For each detection, the following information must be noted:
(i) Species identification (if possible); call type and number of calls (if known); temporal
aspects of vocalization (date, time, duration, etc.; date times in ISO 8601 format); confidence of
detection (detected, or possibly detected); comparison with any concurrent visual sightings;
location and/or directionality of call (if determined) relative to acoustic recorder or construction
activities; location of recorder and construction activities at time of call; name and version of
detection or sound analysis software used, with protocol reference; minimum and maximum
frequencies viewed/monitored/used in detection (in Hz); and name of PAM operator(s) on duty.
(ii) [Reserved]
(6) LOA Holder must compile and submit weekly reports to NMFS Office of Protected
Resources that document the daily start and stop of all pile driving, drilling, UXO/MEC
detonations, and HRG survey associated with the Project; the foundation/pile ID, type of pile,
pile diameter, start and finish time of each drilling and pile driving event, hammer log (number
of strikes, max hammer energy, duration of piling) per pile, any changes to noise attenuation
systems and/or hammer schedule, the start and stop of associated observation periods by PSOs
and PAM operators; details on the deployment of PSOs and PAM operators; a record of all
detections of marine mammals (acoustic and visual) including time (UTC) of sighting/detection,
species ID, behavior, distance (meters) from vessel to animal at time of sighting/detection
(meters), animal distance (meters) from pile installation vessel and UXO/MEC detonation site,
vessel/project activity at time of sighting/detection, platform/vessel name, and mitigation
measures taken (if any) and reason. Sightings/detections during pile driving, drilling, and
UXO/MEC activities (clearance, active pile driving and drilling, post-pile driving and drilling
and detonation) and all other (transit, opportunistic, etc.) sightings/detection must be reported

and identified as such; any mitigation actions (or if mitigation actions could not be taken,
provide reasons why); and details on the noise attenuation system(s) used and its performance.
Weekly reports are due on Wednesday for the previous week (Sunday – Saturday), can consist
of Quality Assurance/Quality Compliance (QA/QC) reviewed data, and must include the
information required under this section. The weekly report must also identify which turbines
become operational and when (a map must be provided). This weekly report must also identify
when, what charge weight size, and where UXO/MECs are detonated (a map must also be
provided). The weekly reports must also confirm that the required SFV was carried out for each
pile and UXO/MEC detonation and that results were reviewed on the required timelines.
Abbreviated SFV reports must be appended to the weekly report. Once all foundation pile
installation and UXO/MEC detonations are completed, weekly reports are no longer required by
LOA Holder;
(7) LOA Holder must compile and submit monthly reports to NMFS Office of Protected
Resources that include a summary of all information in the weekly reports, including project
activities carried out in the previous month, including dates and location of any fisheries
surveys carried out, vessel transits (number, type of vessel, MMIS number, number of transits,
vessel activity, and route (origin and destination, including transits from all ports, foreign and
domestic)), cable installation activities (including sea to shore transition),number of piles
installed and pile IDs, UXO/MEC detonation, all detections of marine mammals
(sightings/detections must include species ID, time, date, initial detection distance,
vessel/platform name, vessel activity, vessel speed, bearing to animal, project activity), and any
mitigative action taken (or if mitigation actions could not be taken, provide reasons why).
Monthly reports are due on the 15th of the month for the previous month. The monthly report
must also identify which turbines become operational and when (a map must be provided). This
weekly report must also identify when, what charge weight size, and where UXO/MECs are
detonated (a map must also be provided);

(8) LOA Holder must submit a draft annual report to NMFS Office of Protected
Resources no later than 90 days following the end of a given calendar year. LOA Holder must
provide a final report within 30 days following resolution of NMFS’s comments on the draft
report. The draft and final reports must detail the following:
(i) A summary of all activities conducted, the dates and locations of all fisheries surveys,
including location and duration for all trawl surveys summarized by month, number of vessel
transits inclusive of port of origin and destination, and a summary table of any observations and
captures of Endangered Species Act (ESA) listed species during these surveys. The report must
also summarize all acoustic telemetry and benthic monitoring activities that occurred, inclusive
of vessel transits. Each annual report is due by February 15 (e.g., the report for 2024 activities is
due by February 15, 2025). The total number of marine mammals of each species/stock detected
and how many were within the designated Level A harassment and Level B harassment zone(s)
with comparison to authorized take of marine mammals for the associated activity type; marine
mammal detections and behavioral observations before, during, and after each activity; what
mitigation measures were implemented (i.e., number of shutdowns or clearance zone delays,
etc.) or, if no mitigative actions was taken, why not; operational details (i.e., days and duration
of impact and vibratory pile driving, days and duration of drilling, days and number of
UXO/MEC detonations, days and amount of HRG survey effort, etc.); any PAM systems used;
The results, effectiveness, and which noise attenuation systems were used during relevant
activities (i.e., impact and vibratory pile driving, drilling, and UXO/MEC detonations);
summarized information related to situational reporting; and any other important information
relevant to the Project, including additional information that may be identified through the
adaptive management process. The final annual report must be prepared and submitted within
30 calendar days following the receipt of any comments from NMFS Office of Protected
Resources on the draft report. If no comments are received from NMFS Office of Protected

Resources within 60 calendar days of NMFS Office of Protected Resources’ receipt of the draft
report, the report must be considered final.
(ii) [Reserved]
(9) LOA Holder must submit its draft final report to NMFS Office of Protected
Resources on all visual and acoustic monitoring conducted within 90 calendar days of the
completion of the specified activities. A 5-year report must be prepared and submitted within 60
calendar days following receipt of any NMFS Office of Protected Resources comments on the
draft report. If no comments are received from NMFS Office of Protected Resources within 60
calendar days of NMFS Office of Protected Resources receipt of the draft report, the report shall
be considered final. The draft and final 5-year report must include, but is not limited to: the total
number (annually and across all 5 years) of marine mammals of each species/stock detected and
how many were detected within the designated Level A harassment and Level B harassment
zone(s) with comparison to authorized take of marine mammals for the associated activity; a
summary table(s) indicating the amount of each activity type (e.g., pile installation, UXO/MEC
detonations, HRG) completed in each of the 5 years and total; Geographic Information System
(GIS) shapefile(s) of the final location of all piles, cable routes, and other permanent structures
including an indication of what year installed and began operating; GIS shapefile of all North
Atlantic right whale sightings, including dates and group sizes; a 5-year summary and
evaluation of all SFV data collected; a 5-year summary and evaluation of all PAM data
collected; a 5-year summary and evaluation of marine mammal behavioral observations; a 5year summary and evaluation of mitigation and monitoring implementation and effectiveness;
and a list of recommendations to inform environmental compliance assessments for future
offshore wind actions;
(10) LOA Holder must submit a SFV plan at least 180 days prior to the planned start of
vibratory and impact pile driving, drilling, and UXO/MEC detonations. The plan must detail all
plans and procedures for noise attenuation, including procedures for adjusting and optimizing

the noise attenuation system(s), maintenance procedures and timelines, and detail the available
contingency noise attenuation measures/systems if distances to modeled isopleths of concern
are exceeded (as documented during SFV). At minimum, the plan must describe how LOA
Holder would ensure that the first three monopile and two jacket (using pin piles) foundation
installation sites selected for SFV are representative of the rest of the monopile and pin pile
installation sites. LOA Holder must provide justification for why these locations are
representative of the scenario modeled. The plan must describe how LOA Holder will conduct
the required Abbreviated SFV, inclusive of requirements to review results within 24 hours and
triggers for Thorough SFV. The plan must provide a table of the identification number and
coordinates of each foundation location, and specify the underwater acoustics analysis model
scenario against which each foundation location’s SFV results will be compared. The plan(s)
must also include the piling schedule and sequence of events, communication and reporting
protocols, and methodology for collecting, analyzing, and preparing SFV data for submission to
NMFS, including instrument deployment, locations of all hydrophones (including direction and
distance from the pile), hydrophone sensitivity, recorder/measurement layout, and analysis
methods. The plan must also identify the number and distance of relative location of
hydrophones for Thorough and Abbreviated SFV. The plan must include a template of the
interim report to be submitted and describe all the information that will be reported in the SFV
Interim Reports including the number, location, depth, distance, and predicted and actual
isopleth distances that will be included in the final report(s). The plan must describe how the
interim SFV report results will be evaluated against the modeled results, including which
modeled scenario the results will be reported against, and include a decision tree of what
happens if measured values exceed predicted values. The plan must address how LOA Holder
will implement the measures associated with the required SFV which includes, but is not
limited to, identifying additional or modified noise attenuation measures (e.g., additional noise
attenuation device, adjust hammer operations, adjust or modify the noise mitigation system) that

will be applied to reduce sound levels if measured distances are greater than those modeled as
well as implementation of any expanded clearance or shutdown zones, including deployment of
additional PSOs. In the case that these sites/scenarios are not determined to be representative of
all other monopile/pin pile installation sites, LOA Holder must include information on how
additional sites/scenarios would be selected for SFV. The plan must also include methodology
for collecting, analyzing, and preparing SFV data for submission to NMFS Office of Protected
Resources. The plan must describe how the effectiveness of the noise attenuation methodology
would be evaluated based on the results.
(i) LOA Holder must also provide, as soon as they are available but no later than 48
hours after each installation, the initial results of the SFV measurements to NMFS Office of
Protected Resources in an interim report after each monopile for the first three piles, after two
jacket foundation using pin piles are installed, and after each UXO/MEC detonation; The plan
must describe how LOA Holder will conduct the required Thorough SFV for all planned
UXO/MEC detonations. Thorough SFV consists of: SFV measurements made at a minimum of
four distances from the detonation, along a single transect, in the direction of lowest
transmission loss (i.e., projected lowest transmission loss coefficient), including, but not limited
to, 750 m and three additional ranges selected such that measurement of identified isopleths are
accurate, feasible, and avoid extrapolation. At least one additional measurement at an azimuth
90 degrees from the array at approximately 750 m must be made. At each location, there must
be a near bottom and mid-water column hydrophone (measurement systems). The plan must
describe how the interim SFV report results will be evaluated against the modeled results and
decision tree of what happens if measured values exceed predicted values. The plan must
address how LOA Holder will implement the measures associated with the required SFV which
includes, but is not limited to, identifying additional or modified noise attenuation measures
(e.g., additional noise attenuation device, adjust hammer operations, adjust or modify the noise
mitigation system) that will be applied to reduce sound levels if measured distances are greater

than those modeled as well as implementation of any expanded clearance or shutdown zones,
including deployment of additional PSOs;
(ii) The interim report must include data from hydrophones identified for interim
reporting in the SFV Plan and include a summary of pile installation activities (pile diameter,
pile weight, pile length, water depth, sediment type, hammer type, total strikes, total installation
time (start time, end time), duration of pile driving, max single strike energy, NAS
deployments), pile location, recorder locations, modeled and measured distances to thresholds,
received levels (rms, peak, and sound exposure level (SEL)) results from Conductivity,
Temperature, and Depth (CTD) casts/sound velocity profiles, signal and kurtosis rise times, pile
driving plots, activity logs, weather conditions. Additionally, any important noise attenuation
device malfunctions (suspected or definite), must be summarized and substantiated with data
(e.g. photos, positions, environmental data, directions, etc.). Such malfunctions include gaps in
the bubble curtain, significant drifting of the bubble curtain, and any other issues which may
indicate sub-optimal mitigation performance or are used by LOA Holder to explain performance
issues;
(iii) The SFV plan must also include how operational noise would be monitored. LOA
Holder must estimate source levels (at 10 m from the operating foundation) based on received
levels measured at distances described in a NMFS-approved SFV plan for operations. These
data must be used to identify estimated transmission loss rates. Operational parameters (e.g.,
direct drive/gearbox information, turbine rotation rate) as well as sea state conditions and
information on nearby anthropogenic activities (e.g., vessels transiting or operating in the area)
must be reported;
(iv) For those foundations and UXO/MEC detonations requiring Thorough SFV
measurements, LOA Holder must provide the initial results of the SFV measurements to NMFS
Office of Protected Resources in an interim report after each foundation installation event as
soon as they are available and prior to any subsequent foundation installation, but no later than

48 hours after each completed foundation installation event. The report must include hammer
energies/schedule used during pile driving or UXO/MEC weight (including donor charge
weight), the model-estimated acoustic ranges (R95%) to compare with the real-world sound
field measurements, estimated source levels at 1 m and/or 10 m, peak sound pressure level
(SPLpk) and median, mean, maximum, and minimum root-mean-square sound pressure level
that contains 90 percent of the acoustic energy (SPLrms) and sound exposure level (SEL, in
single strike for pile driving (SELs-s) and SELcum) for each hydrophone, including at least the
maximum, arithmetic mean, minimum, median (L50) and L5 (95 percent exceedance) statistics
for each metric; estimated marine mammal Level A harassment and Level B harassment
acoustic isopleths, calculated using the maximum-over-depth L5 (95 percent exceedance level,
maximum of both hydrophones) of the associated sound metric; comparison of modeled results
assuming 10-dB attenuation against the measured marine mammal Level A harassment and
Level B harassment acoustic isopleths; estimated transmission loss coefficients; pile identifier
name, location of the pile and each hydrophone array in latitude/longitude; depths of each
hydrophone; one-third-octave band single strike SEL spectra; if filtering is applied, full filter
characteristics must be reported; and hydrophone specifications including the type, model, and
sensitivity. LOA Holder must also report any immediate observations which are suspected to
have a significant impact on the results including but not limited to: observed noise mitigation
system issues, obstructions along the measurement transect, and technical issues with
hydrophones or recording devices. If any in situ calibration checks for hydrophones reveal a
calibration drift greater than 0.75 dB, pistonphone calibration checks are inconclusive, or
calibration checks are otherwise not effectively performed, LOA Holder must indicate full
details of the calibration procedure, results, and any associated issues in the 48-hour interim
reports;
(v) All results from Abbreviated SFV must be included in the weekly reports. The report
must include estimated source levels at 1 m or 10 m and the measured SELcum noise levels at

distance. Any indications that distances to the identified Level A harassment and Level B
harassment thresholds for marine mammals were exceeded must be addressed by LOA Holder,
including an explanation of factors that contributed to the exceedance and corrective actions that
were taken to avoid exceedance on subsequent piles;
(vi) The final results of all SFV measurements from each foundation installation and
UXO/MEC detonations must be submitted as soon as possible, but no later than within 90 days
following completion of each event’s SFV measurements. The final results of Thorough SFV
for UXO/MEC detonations must be submitted as soon as possible, but no later than within 90
days following completion of each UXO/MEC detonation. Within 60 days of the end of each
construction season, LOA Holder must compile and submit all final Abbreviated SFV reports.
The final reports must include all details included in the interim report and descriptions of any
notable occurrences, explanations for results that were not anticipated, or actions taken during
foundation installation. The final report must also include at least the maximum, mean,
minimum, median (L50) and L5 (95 percent exceedance) statistics for each metric; the SEL and
SPL power spectral density and/or one-third octave band levels (usually calculated as
decidecade band levels) at the receiver locations should be reported; range of transmission loss
coefficients; the local environmental conditions, such as wind speed, transmission loss data
collected on-site (or the sound velocity profile); baseline pre- and post-activity ambient sound
levels (broadband and/or within frequencies of concern); a description of depth and sediment
type, as documented in the Construction and Operation Plan (COP), at the recording and
foundation installation and UXO/MEC detonation locations; the extents of the measured Level
A harassment and Level B harassment zone(s); hammer energies required for pile installation
and the number of strikes per pile; and charge weights and other relevant characteristics of
UXO/MEC detonations; the hydrophone equipment and methods (i.e., recording device,
bandwidth/sampling rate, distance from the monopile/pin pile and/or UXO/MEC where
recordings were made; depth of recording device(s)); a description of the SFV measurement

hardware and software, including software version used, calibration data, bandwidth capability
and sensitivity of hydrophone(s), any filters used in hardware or software, any limitations with
the equipment, and other relevant information; the spatial configuration of the noise attenuation
device(s) relative to the pile and/or UXO/MEC charge; a description of the noise abatement
system and operational parameters (e.g., bubble flow rate, distance deployed from the pile
and/or UXO/MEC, etc.) and any action taken to adjust the noise abatement system. A
discussion which includes any observations which are suspected to have a significant impact on
the results including but not limited to: observed noise mitigation system issues, obstructions
along the measurement transect, and technical issues with hydrophones or recording devices.
LOA Holder must submit a revised report within 30 days following receipt of NMFS’
comments on the draft final report;
(vii) LOA Holder must submit SFV results from UXO/MEC detonation monitoring in a
report prior to detonating a subsequent UXO/MEC or within the relevant weekly report,
whichever comes first. The report must include, at minimum, the size of UXO/MEC detonated
and donor charge weight, why detonation was necessary, current speeds, SELcum, a description
of the noise abatement system and operational parameters (e.g., bubble flow rate, distance
deployed from the detonation, etc.) and any action taken to adjust the noise abatement system,
modeled and SFV-based estimated ranges to all relevant NMFS explosive thresholds (including
those from pressure transducer measurements); and
(viii) If at any time during the project LOA Holder becomes aware of any issue or issues
which may (to any reasonable subject-matter expert, including the persons performing the
measurements and analysis) call into question the validity of any measured Level A harassment
or Level B harassment isopleths to a significant degree, which were previously transmitted or
communicated to NMFS Office of Protected Resources, LOA Holder must inform NMFS
Office of Protected Resources within 1 business day of becoming aware of this issue or before
the next pile is driven, whichever comes first.

(11) If a North Atlantic right whale is acoustically detected at any time by a projectrelated PAM system, LOA Holder must ensure the detection is reported as soon as possible to
NMFS, but no longer than 24 hours after the detection via the 24-hour North Atlantic right
whale Detection Template (https://www.fisheries.noaa.gov/resource/document/passiveacoustic-reporting-system-templates). Calling the hotline is not necessary when reporting PAM
detections via the template. Full detection data, metadata, and location of recorders (or GPS
tracks, if applicable) from all real-time hydrophones used for monitoring during construction
must be submitted within 90 calendar days following completion of activities requiring PAM
for mitigation via the ISO standard metadata forms available on the NMFS Passive Acoustic
Reporting System website (https://www.fisheries.noaa.gov/resource/document/passiveacoustic-reporting-system-templates). Submit the completed data templates to
nmfs.nec.pacmdata@noaa.gov. The full acoustic recordings from real-time systems must also
be sent to the NCEI for archiving within 90 days following completion of activities requiring
PAM for mitigation. Submission details can be found at:
https://www.ncei.noaa.gov/products/passive-acoustic-data;
(12) LOA Holder must submit situational reports if the following circumstances occur,
including all instances wherein an exemption is taken must be reported to NMFS Office of
Protected Resources within 24 hours, in specific circumstances, including but not limited to the
following:
(i) All sightings of North Atlantic right whale must be reported immediately (no later
than 24 hours). If a North Atlantic right whale is sighted with no visible injuries or
entanglement at any time by project PSOs or project personnel, LOA Holder must immediately
report the sighting to NMFS. If immediate reporting is not possible, the report must be
submitted as soon as possible but no later than 24 hours after the initial sighting. All North
Atlantic right whale acoustic detections within a 24-hour period should be collated into one
spreadsheet and reported to NMFS as soon as possible but no later than 24 hours.

(A) To report sightings and acoustic detections, download and complete the Real-Time
North Atlantic Right Whale Reporting Template spreadsheet found here:
https://www.fisheries.noaa.gov/resource/document/template-datasheet-real-time-north-atlanticright-whale-acoustic-and-visual. Save the completed spreadsheet as a .csv file and email it to
NMFS Northeast Fisheries Science Center Protected Species Division (NEFSC-PSD)
(ne.rw.survey@noaa.gov), NMFS GARFO Protected Species Division (PRD)
(nmfs.gar.incidental-take@noaa.gov), and NMFS Office of Protected Resources
(pr.itp.monitoringreports@noaa.gov). If the sighting is in the Southeast (North Carolina
through Florida), report via the template and to the Southeast Hotline 877-WHALE-HELP
(877-942-5343) with the observation information provided below (PAM detections are not
reported to the Hotline). If unable to report a sighting through the spreadsheet within 24 hours,
call the relevant regional hotline (Greater Atlantic Region [Maine through Virginia] Hotline
866-755-6622; Southeast Hotline 877-WHALE-HELP) with the observation information
provided below (PAM detections are not reported to the Hotline).
(B) The following information must be reported: the time (note time format), date
(MM/DD/YYYY), location (latitude/longitude in decimal degrees; coordinate system used) of
the observation, number of whales, animal description/certainty of observation (follow up with
photos/video if taken), reporter’s contact information, and lease area number/project name,
PSO/personnel name who made the observation, and PSO provider company (if applicable)
(PAM detections are not reported to the Hotline). If unable to report via the template or the
regional hotline, enter the sighting via the WhaleAlert app (http://www.whalealert.org/). If this
is not possible, report the sighting to the U.S. Coast Guard via channel 16. The report to the
Coast Guard must include the same information as would be reported to the Hotline (see above).
PAM detections are not reported to WhaleAlert or the U.S. Coast Guard.

(C) If a large whale species is observed that is not a North Atlantic right whale, LOA
Holder must report the sighting via the WhaleAlert app (http://www.whalealert.org/) as soon as
possible but within 24 hours.
(ii) In the event that personnel involved in the Project discover a stranded, entangled,
injured, or dead marine mammal, LOA Holder must immediately report the observation to
NMFS. If in the Greater Atlantic Region (Maine through Virginia), call the NMFS Greater
Atlantic Stranding Hotline (866-755-6622), and if in the Southeast Region (North Carolina
through Florida) call the NMFS Southeast Stranding Hotline (877-WHALE-HELP (877-9425343)). Separately, LOA Holder must report, within 24 hours, the incident to NMFS Office of
Protected Resources (PR.ITP.MonitoringReports@noaa.gov) and, if in the Greater Atlantic
Region to the NMFS GARFO (nmfs.gar.incidental-take@noaa.gov) or if in the Southeast
Region, to the NMFS Southeast Regional Office (SERO; secmammalreports@noaa.gov). Note,
the stranding hotline may request the report be sent to the local stranding network response
team. The report must include contact information (e.g., name, phone number, etc.); time, date,
and location (i.e., specify coordinate system) of the first discovery (and updated location
information, if known and applicable); species identification (if known) or description of the
animal(s) involved; condition of the animal(s) (including carcass condition if the animal is
dead); observed behaviors of the animal(s) (if alive); photographs or video footage of the
animal(s) (if available); and general circumstances under which the animal was discovered.
(iii) In the event of a suspected or confirmed vessel strike of a marine mammal by any
vessel associated with the Project or other means by which Project activities caused a nonauditory injury or death of a marine mammal, LOA Holder must immediately report the
incident to NMFS. If in the Greater Atlantic Region (Maine through Virginia), call the NMFS
Greater Atlantic Stranding Hotline (866-755-6622), and if in the Southeast Region (North
Carolina through Florida) call the NMFS Southeast Stranding Hotline (877-WHALE-HELP
(877-942-5343)). Separately, LOA Holder must immediately report the incident to NMFS

Office of Protected Resources (PR.ITP.MonitoringReports@noaa.gov) and, if in the Greater
Atlantic Region to the NMFS GARFO (nmfs.gar.incidental-take@noaa.gov) or if in the
Southeast Region, to the NMFS SERO (secmammalreports@noaa.gov). The report must
include time, date, and location (i.e., specify coordinate system)) of the incident; species
identification (if known) or description of the animal(s) involved (i.e., identifiable features
including animal color, presence of dorsal fin, body shape and size, etc.); vessel strike reporter
information (name, affiliation, email for person completing the report); vessel strike witness (if
different than reporter) information (e.g., name, affiliation, phone number, platform for person
witnessing the event, etc.); vessel name and/or MMSI number; vessel size and motor
configuration (inboard, outboard, jet propulsion); vessel’s speed leading up to and during the
incident; vessel’s course/heading and what operations were being conducted (if applicable); part
of vessel that struck marine mammal (if known); vessel damage notes; status of all sound
sources in use at the time of the strike; if the marine mammal was seen before the strike event;
description of behavior of the marine mammal before the strike event (if seen) and behavior
immediately following the strike; description of avoidance measures/requirements that were in
place at the time of the strike and what additional measures were taken, if any, to avoid strike;
environmental conditions (e.g., wind speed and direction, Beaufort sea state, cloud cover,
visibility, etc.) immediately preceding the strike; estimated (or actual, if known) size and length
of marine mammal that was struck; if available, description of the presence and behavior of any
other marine mammals immediately preceding the strike; other animal-specific details if known
(e.g., length, sex, age class); behavior or estimated fate of the marine mammal post-strike (e.g.,
dead, injured but alive, injured and moving, external visible wounds (linear wounds, propeller
wounds, non-cutting blunt-force trauma wounds), blood or tissue observed in the water, status
unknown, disappeared); to the extent practicable, any photographs or video footage of the
marine mammal(s); and, any additional notes the witness may have from the interaction. For
any numerical values provided (i.e., location, animal length, vessel length, etc.), please provide

if values are actual or estimated. LOA Holder must immediately cease activities until the NMFS
Office of Protected Resources is able to review the circumstances of the incident and determine
what, if any, additional measures are appropriate to ensure compliance with the terms of the
LOA(s). NMFS Office of Protected Resources may impose additional measures to minimize the
likelihood of further prohibited take and ensure MMPA compliance. LOA Holder must not
resume their activities until notified by NMFS Office of Protected Resources.
(13) LOA Holder must report any lost gear associated with the fishery surveys to the
NOAA GARFO-PRD (nmfs.gar.incidental-take@noaa.gov) as soon as possible or within 24
hours of the documented time of missing or lost gear. This report must include information on
any markings on the gear and any efforts undertaken or planned to recover the gear;
(14) LOA Holder must provide NMFS Office of Protected Resources with notification
of planned UXO/MEC detonation as soon as possible but at least 48 hours prior to the planned
detonation, unless this 48-hour notification would create delays to the detonation that would
result in imminent risk of human life or safety. This notification must include the coordinates of
the planned detonation, the estimated charge size, and any other information available on the
characteristics of the UXO/MEC. If an UXO/MEC detonation occurs, within 72 hours after a
detonation but before the next detonation, whichever is sooner, LOA Holder must report to
NMFS Office of Protected Resources the time, date, location (latitude/longitude Decimal
Degrees), charge weight size, justification on why detonation was necessary and other means of
removal or avoidance could not occur, all detections of marine mammals within the UXO/MEC
zones, and any mitigative action taken; and
(15) Performance reports for piles with SFV must be submitted by LOA Holder with the
weekly pile driving reports. For UXO/MEC detonations, the report must be submitted as soon
as it is available, but no later than when the interim SFV report is submitted for the UXO/MEC
detonation.

(16) Performance reports for each bubble curtain deployed must include water depth,
current speed and direction, wind speed and direction, bubble curtain deployment/retrieval date
and time, bubble curtain hose length, bubble curtain radius (distance from pile), diameter of
holes and hole spacing, air supply hose length, compressor type (including rated Cubic Feet per
Minute (CFM) and model number), number of operational compressors, performance data from
each compressor (including Revolutions Per Minute (RPM), pressure, start times, and stop
times), free air delivery (m³/min), total hose air volume (m³/(min m)), schematic of GPS
waypoints during hose laying, maintenance procedures performed (pressure tests, inspections,
flushing, re-drilling, and any other hose or system maintenance) before and after installation and
timing of those tests, and the length of time the bubble curtain was on the seafloor prior to
foundation installation.
(i) The report must include any important observations regarding performance (before,
during, and after pile installation or UXO/MEC detonation), such as any observed weak areas of
low pressure. The report may also include any relevant video and/or photographs of the bubble
curtain(s) operating during pile driving (inclusive of relief drilling) and UXO/MEC detonation.
(ii) [Reserved].
§ 217.326 Letter of Authorization.
(a) To incidentally take marine mammals pursuant to this subpart, LOA Holder must
apply for and obtain an LOA.
(b) A LOA, unless suspended or revoked, may be effective for a period of time not to
exceed March 26, 2030, the expiration date of this subpart.
(c) In the event of projected changes to the activity or to mitigation and monitoring
measures required by an LOA, LOA Holder must apply for and obtain a modification of the
LOA as described in § 217.327.
(d) The LOA must set forth:

(1) Permissible methods of incidental taking;
(2) Means of effecting the least practicable adverse impact (i.e., mitigation) on the
species, its habitat, and on the availability of the species for subsistence uses; and
(3) Requirements for monitoring and reporting.
(e) Issuance of the LOA must be based on a determination that the level of taking must
be consistent with the findings made for the total taking allowable under the regulations of this
subpart.
(f) Notice of issuance or denial of an LOA must be published in the Federal Register
within 30 days of a determination.
§ 217.327 Modifications of Letter of Authorization.
(a) A LOA issued under §§ 217.322 and 217.326 or this section for the activity
identified in § 217.320(c) shall be modified, upon request by LOA Holder, provided that:
(1) The specified activity and mitigation, monitoring, and reporting measures, as well as
the anticipated impacts, are the same as those described and analyzed for this subpart (excluding
changes made pursuant to the adaptive management provision in paragraph (c)(1) of this
section); and
(2) NMFS determines that the mitigation, monitoring, or reporting measures required by
the previous LOA under this subpart were implemented.
(b) For a LOA modification request by the applicant that includes changes to the activity
or the mitigation, monitoring, or reporting measures (excluding changes made pursuant to the
adaptive management provision in paragraph (c)(1) of this section), the LOA shall be modified,
provided that:
(1) NMFS determines that the changes to the activity or the mitigation, monitoring, or
reporting do not change the findings made for the regulations in this subpart and do not result in

more than a minor change in the total estimated number of takes (or distribution by species or
years), and
(2) NMFS may publish a notice of proposed modified LOA in the Federal Register,
including the associated analysis of the change, and solicit public comment before issuing the
LOA.
(c) A LOA issued under §§ 217.322 and 217.326 or this section for the activities
identified in § 217.320(a) may be modified by NMFS Office of Protected Resources under the
following circumstances:
(1) Through adaptive management, NMFS may modify (including remove, revise, or
add to) the existing mitigation, monitoring, or reporting measures after consulting with LOA
Holder regarding the practicability of the modifications, if doing so creates a reasonable
likelihood of more effectively accomplishing the goals of the mitigation and monitoring
measures set forth in this subpart;
(i) Possible sources of data that could contribute to the decision to modify the
mitigation, monitoring, or reporting measures in an LOA include, but are not limited to:
(A) Results from LOA Holder’s monitoring;
(B) Results from other marine mammals and/or sound research or studies; and
(C) Any information that reveals marine mammals may have been taken in a manner,
extent, or number not authorized by this subpart or subsequent LOA.
(ii) If, through adaptive management, the modifications to the mitigation, monitoring, or
reporting measures are substantial, NMFS shall publish a notice of proposed LOA in the
Federal Register and solicit public comment.
(2) If the NMFS Office of Protected Resources determines that an emergency exists that
poses a significant risk to the well-being of the species or stocks of marine mammals specified
in the LOA issued pursuant to §§ 217.322 and 217.326 or this section, a LOA may be modified

without prior notice or opportunity for public comment. Notice would be published in the
Federal Register within 30 days of the action.
§§ 217.328 - 217.329 [Reserved]
[FR Doc. 2024-12085 Filed: 6/20/2024 8:45 am; Publication Date: 6/21/2024]