BILLING CODE 3510-22-P
DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
50 CFR Part 217
[Docket No. 240621-0172}
RIN 0648-BM74
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals
Incidental to U.S. Navy Repair and Replacement of the Q8 Bulkhead at Naval Station
Norfolk

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric
Administration (NOAA), Commerce.
ACTION: Proposed rule, request for comment.
SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for authorization to
take marine mammals incidental to the Q8 Bulkhead repair and replacement project at Naval
Station (NAVSTA) Norfolk in Norfolk, Virginia over the course of 5-years (i.e., 2025-2029)
(the Project). Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is proposing
regulations to govern that take, and requests comments on the proposed regulations. Agency
responses will be included in the notice of the final decision.
DATES: Comments and information must be received no later than [INSERT DATE 30
DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].
ADDRESSES: A copy of the Navy's application and any supporting documents, as well as a
list of the references cited in this document, may be obtained online at:

https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navys-constructionactivities-q8-bulkhead-naval-station.
In case of problems accessing these documents, please call the contact listed below (see FOR
FURTHER INFORMATION CONTACT).
Submit all electronic public comments via the Federal e-Rulemaking Portal. Go to
https://www.regulations.gov and enter NOAA-NMFS-2024-0055 in the Search box. Click on
the “Comment” icon, complete the required fields, and enter or attach your comments.
Instructions: Comments sent by any other method, to any other address or individual,
or received after the end of the comment period, may not be considered by NMFS. All
comments received are a part of the public records and will generally be posted for public
viewing on https://www.regulations.gov without change. All personal identifying information
(e.g., name, address), confidential business information, or otherwise sensitive information
submitted voluntarily by the sender will be publicly accessible. NMFS will accept
anonymous comments (enter “N/A” in the required fields if you wish to remain anonymous).
Attachments to electronic comments will be accepted in Microsoft Word, Excel, or Adobe
PDF file formats only.
FOR FURTHER INFORMATION CONTACT: Craig Cockrell, Office of Protected
Resources, NMFS, (301) 427-8401 or craig.cockrell@noaa.gov.
SUPPLEMENTARY INFORMATION:
Purpose and Need for Regulatory Action
This proposed rule would establish a framework under the authority of the MMPA
(16 U.S.C. 1361 et seq.) to allow for the authorization of take of marine mammals incidental
to the Navy's construction activities including pile driving at NAVSTA Norfolk.
We received an application from the Navy requesting 5-year regulations and
authorization to take multiple species of marine mammals. Take would occur by Level B
harassment, incidental to impact and vibratory pile driving. Please see Background below
for definitions of harassment.
Legal Authority for the Proposed Action
Section 101(a)(5)(A) of the MMPA (16 U.S.C. 1371(a)(5)(A)) directs the Secretary
of Commerce 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 for up to 5-years if, after notice
and public comment, the agency makes certain findings and issues regulations that set forth
permissible methods of taking pursuant to that activity and other means of effecting the “least
practicable adverse impact” on the affected species or stocks and their habitat (see the
discussion below in the Proposed Mitigation section), as well as monitoring and reporting
requirements. Section 101(a)(5)(A) of the MMPA, and the implementing regulations at 50
CFR part 216 subpart I, provide the legal basis for issuing this proposed rule containing 5year regulations, and for any subsequent letters of authorization (LOAs). As directed by this
legal authority, this proposed rule contains mitigation, monitoring, and reporting
requirements.
Summary of Major Provisions Within the Proposed Rule
Following is a summary of the major provisions of this proposed rule regarding Navy
construction activities. These measures include:
•

Required monitoring of the construction areas to detect the presence of marine
mammals before beginning construction activities;

•

Shutdown of construction activities under certain circumstances to avoid injury of
marine mammals; and

•

Soft start for impact pile driving to allow marine mammals the opportunity to leave
the area prior to beginning impact pile driving at full power.

Background
The MMPA prohibits the “take” of marine mammals, with certain exceptions Section
101(a). 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 and either regulations are proposed or, if the taking is limited to
harassment, a notice of a proposed IHA is provided to the public for review.
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. Further, NMFS must prescribe the permissible methods of taking and 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 in shorthand as “mitigation”); and requirements pertaining to the
mitigation, monitoring and reporting of the takings are set forth (Section 101
(5)(A)(i)(II)(aa)). The definitions of all applicable MMPA statutory terms cited above are
included in the relevant sections below.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA; 42 U.S.C.
4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, NMFS must review our

proposed action (i.e., the issuance of regulations) with respect to potential impacts on the
human environment.
This action is consistent with categories of activities identified in Categorical
Exclusion B4 (i.e., incidental harassment authorizations (IHAs) with no anticipated serious
injury or mortality) of the Companion Manual for NAO 216-6A, which do not individually or
cumulatively have the potential for significant impacts on the quality of the human
environment and for which we have not identified any extraordinary circumstances that
would preclude this categorical exclusion. Accordingly, NMFS has preliminarily determined
that the issuance of the proposed regulations and LOA qualifies to be categorically excluded
from further NEPA review.
We will review all comments submitted in response to this notice prior to concluding
our NEPA process or making a final decision on final regulations and the final LOA.
Summary of Request
On September 14, 2024, NMFS received a request from the Navy for authorization to
take marine mammals incidental to repair and replacement of the Q8 Bulkhead at NAVSTA
Norfolk in Norfolk, VA. Following NMFS’ review of the application, the Navy submitted a
revised version on December 18, 2024 and after review of that application a second revised
version was submitted on January 16, 2024. The application was deemed adequate and
complete on February 23, 2024. A notice of receipt of the Navy’s application was published
in the Federal Register on March 14, 2024 (89 FR 18605). No comments were received on
the application during the 30-day comment period. Navy’s request is for the take of four
species by Level B harassment only. Neither Navy nor NMFS expect serious injury or
mortality to result from this activity. The proposed regulations would be valid for 5 years
(2025-2029).

Description of Proposed Activity
Overview
The Navy proposes to repair and replace the Q8 bulkhead at NAVSTA Norfolk,
originally constructed in 1957, that has failed in multiple locations, creating sinkholes and
unsafe conditions. Work on the bulkhead would be conducted from Piers 12 and 14 to restore
function of this Navy dock system. Vibratory and impact hammers would be used for pile
removal and installation. Sounds produced from these pile removal and installation activities
may result in the incidental take of marine mammals by Level B harassment in the form of
behavioral harassment. The Q8 bulkhead consists of an approximately 2,583 feet (ft) (787.30
meters (m) long anchored concrete sheet pile wall, beginning 400-ft (121.92 m) south of Pier
12 and terminating 1,024 ft (312.12 m) north of Pier 14 (the Project Area). The Project
would occur at NAVSTA Norfolk in Norfolk, Virginia near the mouth of the James River.
Work would be conducted over 212 non-consecutive days to complete the proposed pile
removal and installation activities.
Dates and Duration
The proposed regulations would be valid for a period of 5 years (2025-2029). The
specified activities may occur at any time during the 5-year period of validity of the proposed
regulations. The Navy expects pile removal and driving activities for the entire Project to
occur during approximately 212 non-consecutive days over three phases each of which would
take a year to complete, with the greatest amount of work occurring during Phase III (year 3)
(approximately 204 days). However, in the event of unforeseen delays, the Project may occur
over the full 5-year duration of this proposed rule. The Navy plans to conduct all work during
daylight hours.
Specific Geographic Region

The Q8 bulkhead at NAVSTA Norfolk is located at the confluence of the Elizabeth
River, James River, Nansemond River, LaFeyette River, Willoughby Bay, and Chesapeake
Bay (figure 1). The water depth of the proposed action area can vary from six ft (1.83 m) to
50 ft (15.24 m) when measured at mean low water. The station is home to 59 ships (including
five aircraft carriers), 187 aircraft, 18 aircraft squadrons, and 326 tenant commands.
Waterfront structures include 13 large piers, numerous small piers, and bulkheads.
Anthropogenic sound is a significant contributor to the ambient acoustic environment
surrounding NAVSTA Norfolk, as it is located in close proximity to shipping channels as
well as several Port of Virginia facilities with frequent vessel traffic that altogether have an
annual average of 1,788 vessel calls (Port of Virginia, 2021). Other sources of humangenerated underwater sound not specific to naval installations include sounds from
commercial and recreational vessel traffic. Additionally, on average, maintenance dredging
of the navigation channel occurs every 2-years (USACE and Port of Virginia, 2018).

Figure 1. Site Location Map for NAVSTA Norfolk

Figure 2. Location of the Q8 Bulkhead at NAVSTA Norfolk

Detailed Description of the Specified Activity
The proposed Project at NAVSTA Norfolk would involve the repair and replacement
of the Q8 bulkhead. Excavation of the shoreside portion existing bulkhead would occur to
expose the existing concrete relieving platform for inspection, to facilitate removal and
replacement of existing stormwater outfall pipes and catch basins, and to accommodate
installation of a new tie-back rod system. Once the replacement of the stormwater outfall
pipes and catch basins are completed the pile removal and installation activities would begin
in three phases. The new sheet piles would be installed outboard of the existing sheet pile
wall and concrete and composite fender piles would be installed incrementally along the span
of the bulkhead. Pile removal and installation activities over the three phases are presented
below in table 1. Once construction is complete the previously excavated fill material would
be placed in a similar location to allow for repaving of the shoreward area of the bulkhead.
In-water construction activities, include pile removal and installation and are described in
detail below:
Pile Removal – Vibratory hammers are expected to be used to remove piles; however,
a direct pull method or clamshell device may be used to remove piles. These three pile
removal methods are described below. Take is not expected to occur for direct pull and
clamshell removal methods; therefore, they will not be described past what is provided below
nor included in the analysis presented in this rulemaking:
•

Vibratory Extraction – This method uses a barge-mounted crane with a
vibratory driver to remove all pile types. The vibratory driver is a large
mechanical device (5-16 tons) suspended from a crane by a cable and
positioned on top of a pile. The pile is then loosened from the sediments by
activating the driver and slowly lifting up on the driver with the aid of the
crane. Once the pile is released from the sediments, the crane continues to
raise the driver and pull the pile from the sediment. The driver is typically
shut off once the pile is loosened from the sediments. The pile is then pulled
from the water and placed on a barge. Vibratory extraction usually takes
between less than one minute (for timber piles) to 30 minutes per pile
depending on the pile size, type, and substrate conditions;

•

Clamshell—In cases where use of a vibratory driver is not possible (e.g.,
when the pile may break apart from clamp force and vibration), a clamshell
apparatus may be lowered from the crane in order to remove pile stubs. A
clamshell is a hinged steel apparatus that operates similar to a set of steel
jaws. The bucket is lowered from a crane and the jaws grasp the pile stub as
the crane pulls upward. The use and size of the clamshell bucket would be

minimized to reduce the potential for generating turbidity during removal;
and
•

Direct Pull – Piles may be removed by wrapping the piles with a cable or
chain and pulling them directly from the sediment with a crane. In some
cases, depending on access and location, piles may be cut at or below the
mudline.

Pile Installation – Pile installation would occur using both vibratory and impact
hammers. Vibratory hammers install piles by vibrating them and allowing the weight of the
hammer to push them into the sediment. Impact hammers operate by repeatedly dropping a
heavy piston onto a pile to drive the pile into the substrate. Concrete piles and composite
piles would be installed using an impact or vibratory hammer. Steel sheet piles would be
installed only using a vibratory hammer.
Table 1 provides the estimated construction schedule and production rates for the
proposed construction activities considered for this proposed rulemaking beginning with
Phase I. Each phase of the construction would occur over a 1-year period for a total of 3years. Some Project elements will use only one method of pile installation while others may
use two methods (e.g., impact hammer or vibratory hammer and impact hammer), but all pile
driving methods have been analyzed. The method of installation will be determined by the
construction crew once demolition and installation has begun.

Table 1 -- Preliminary Construction Schedule for In-Water Activities
Phase
(Year)

Method of pile
driving/removal

Pile
size/type

Phase I
(Year 1)

Vibratory
removal

18-in Prestressed
concrete
piles
56-in. steel
sheet piles
18-in Prestressed
concrete
piles
18-in Prestressed
concrete
piles
56-in. steel
sheet piles
18-in Prestressed
concrete
piles
16-in.
Composite
piles
56-in. steel
sheet piles
16-in.
Composite
piles
18-in Prestressed
concrete
piles

Vibratory install
Impact install

Phase II
(Year 2)

Vibratory
removal
Vibratory install
Impact install

Phase III
(Year 3)

Vibratory
removal
Vibratory install
Impact install
Impact install

Total
number
of piles
Daily rate
(piles/day)

Total
days

24

6

109

19

6

81

15

6

178

30

6

105

18

6

Total
days in
phase
37

Concurrent Activities—In order to maintain Project schedules, it is likely that
multiple pieces of equipment would operate at the same time within the Project Area. Table 2
provides a summary of the possible equipment combinations by phase where a maximum of
four pieces of in-water equipment may be occurring simultaneously. As mentioned above, the
method of installation, and whether concurrent pile driving scenarios will be implemented,
will be determined by the construction crew once the Project has begun. Therefore, the total
take estimate reflects the highest amount for a given activity during the proposed Project.
Table 2 -- Summary of Possible Concurrent Pile Driving/Removal Equipment
Project phase
Phase I

Equipment types
Total equipment operating
Vibratory hammer (install
3
and removal) and impact
hammer
Phase II
Vibratory hammer (install
3
and removal) and impact
hammer
Phase III
Two Vibratory hammer
4
(install and removal) and
two impact hammers
Proposed mitigation, monitoring, and reporting measures are described in detail later
in this document (see the Proposed Mitigation and Proposed Monitoring and Reporting
sections).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information regarding status
and trends, distribution and habitat preferences, and behavior and life history of the
potentially affected species. NMFS fully considered all of this information, and we refer the
reader to these descriptions, instead of reprinting the information. Additional information
regarding population trends and threats may be found in NMFS’ Stock Assessment Reports
(SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marinemammal-stock-assessments) and more general information about these species (e.g., physical
and behavioral descriptions) may be found on NMFS’ website at:
https://www.fisheries.noaa.gov/find-species.
Table 3 lists all species or stocks for which take is expected and proposed to be
authorized for this activity, and summarizes information related to the population or stock,

including regulatory status under the MMPA and Endangered Species Act (ESA) and
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 (as described in NMFS’ SARs) (Section 3 (19)(A). While no serious injury or
mortality is anticipated or proposed to be authorized here, PBR and annual serious injury and
mortality from anthropogenic sources are included here as gross indicators of the status of the
species or stocks 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’ 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’ U.S. Atlantic SARs. All values presented in table
3 are the most recent available at the time of publication (including from the draft 2023
SARs) and are available online at: https://www.fisheries.noaa.gov/national/marine-mammalprotection/marine-mammal-stock-assessments.

Table 3 -- Species Likely Impacted by the Specified Activities1

Common
name

Scientific name

Stock

ESA/MMPA
status;
Strategic
(Y/N)2

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

PBR

Annual
M/SI4

Order Artiodactyla – Infraorder Cetacea – Mysticeti (baleen whales)
Family Balaenopteridae (rorquals)
Humpback
Megaptera
1,396 (0, 1380,
Gulf of Maine
-,-, N
22
12.15
whale
novaeangliae
2016)
Odontoceti (toothed whales, dolphins, and porpoises)
Family Physeteridae
Northern
6,639 (0.41,
12.2Migratory
-, -, Y
48
4,759, 2016)
21.5
Coastal
Southern
Bottlenose
Tursiops
3,751 (0.6, 2,353,
Migratory
-, -, Y
24
0-18.3
dolphin
truncatus
2016)
Coastal
Northern NC
823 (0.06, 782,
-, -, N
7.8
7.2- 30
Estuarine
2017)
Family Phocoenidae (porpoises)
Harbor
Phocoena
Gulf of Maine/
85,765 (0.53,
-, -, N
649
145
porpoise
phocoena
Bay of Fundy
56,420, 2021)
Order Carnivora – Pinnipedia
Family Phocidae (earless seals)
Western North
61,336 (0.08,
Harbor Seal Phoca vitulina
-, -, N
1,729
339
Atlantic
57,637, 2018)
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://www.marinemammalscience.org/science-and-publications/list-marinemammal-species-subspecies/).
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 human-caused 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 online at:
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marinemammal-stock-assessment-reports/. CV is coefficient of variation; Nmin is the
minimum estimate of stock abundance. In some cases, CV is not applicable.

4 - These values, found in NMFS’s SARs, represent annual levels of human-caused
mortality plus serious injury from all sources combined (e.g., commercial fisheries,
vessel strike). Annual M/SI often cannot be determined precisely and is in some cases
presented as a minimum value or range.
As indicated above, all four species (with six managed stocks) in table 3 temporally
and spatially co-occur with the activity to the degree that take is reasonably likely to occur.
All species that could potentially occur in the proposed action area are included in table 3-1
of the IHA application. While gray seals (Halichoerus grypus) have been documented in the
area, the temporal and/or spatial occurrence of the species is such that take is not expected to
occur, and it is not discussed further beyond the explanation provided here.
Surveys conducted in the lower Chesapeake Bay have observed gray seals regularly
near the mouth of the Bay (Rees et al., 2016; Jones et al. 2018; Jones & Rees, 2020, 2021,
2022). Although gray seals are present at the mouth of the Chesapeake Bay NMFS reviewed
monitoring reports from the Hampton Roads Bridge-Tunnel Expansion Project IHA (85 FR
48153, August 10, 2020) and the Navy Pier 3 IHA (87 FR 15945, March 21, 2022) and there
were no gray seals observed during either of those projects (Hampton Roads Connector
Partners 2023; W.F. Magann Corporation 2023). Therefore, take is not expected for these
species and they are not discussed further in this document.
Humpback Whale
In the winter months, humpback whales from waters off New England, Canada,
Greenland, Iceland, and Norway, migrate to mate and calve primarily in the West Indies,
where spatial and genetic mixing among these groups occurs. NMFS defines a humpback
whale stock on the basis of feeding location (i.e., Gulf of Maine). However, our reference to
humpback whales in this document refers to any individual of the species that are found in
the species geographic region. These individuals may be from the same breeding population
(e.g., West Indies breeding population of humpback whales) but visit different feeding areas.
Prior to 2016, humpback whales were listed under the ESA as an endangered species
worldwide. Following a 2015 global status review (Bettridge et al., 2015), NMFS established
14 Distinct Population Segments (DPSs) with different listing statuses (81 FR 62259,
September 8, 2016) pursuant to the ESA. Humpback whales in the Project Area are expected
to be from the West Indies DPS, which consists of the whales whose breeding range includes
the Atlantic margin of the Antilles from Cuba to northern Venezuela, and whose feeding
range primarily includes the Gulf of Maine, eastern Canada, and western Greenland. This
DPS is not ESA listed. Bettridge et al., (2003) estimated the size of the West Indies DPS at
12,312 (95 percent confidence interval 8,688-15,954) whales in 2004-05, which is consistent
with previous population estimates of approximately 10,000-11,000 whales (Stevick et al.,
2003; Smith et al., 1999) and the increasing trend for the West Indies DPS (Bettridge et al.,
2015).
Since January 2016, elevated humpback whale mortalities have occurred along the
Atlantic coast from Maine through Florida. This event was declared an unusual mortality
event (UME) in 2017. A portion of the whales have shown evidence of pre-mortem vessel
strike; however, this finding is not consistent across all whales examined, and additional
research is needed. Since May 3, 2024, 221 Atlantic humpback whales have been subject to
the active UME. Additional information is available at:
https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2024-humpback-whaleunusual-mortality-event-along-atlantic-coast.
Humpback whales are most likely to occur near the mouth of the Chesapeake Bay
and coastal waters of Virginia Beach between January and March; however, they could be
found in the area year-round, based on shipboard sighting and stranding data (Barco and
Swingle, 2014; Aschettino et al., 2015; 2016; 2017; 2018). Photo-identification data support
the repeated use of the mid-Atlantic region by individual humpback whales. Results of the
vessel surveys show site fidelity in the survey area for some individuals and a high level of
occurrence within shipping channels—an important high-use area by both the Navy and
commercial traffic (Aschettino et al., 2015; 2016; 2017; 2018). Nearshore surveys conducted
in early 2015 reported 61 individual humpback whale sightings, and 135 individual
humpback whale sightings in late 2015 through May 2016 (Aschettino et al., 2016).
Subsequent surveys confirmed the occurrence of humpback whales in the nearshore survey
area: 248 individuals were detected in 2016-2017 surveys (Aschettino et al., 2017), 32
individuals were detected in 2017-2018 surveys (Aschettino et al., 2018), and 80 individuals
were detected in 2019 surveys (Aschettino et al., 2019). Sightings in the Hampton Roads area
in the vicinity of NAVSTA Norfolk were reported in nearshore surveys and through tracking
of satellite-tagged whales in 2016, 2017 and 2019. The numbers of whales detected, most of
which were juveniles, reflect the varying level of survey effort and changes in survey
objectives from year to year, and do not indicate abundance trends over time. Recent
monitoring reports from the Hampton Roads Bridge-Tunnel Expansion Project and the Pier 3
Navy Construction Project did not observe any humpback whales near the project sites.
Monitoring for the Hampton Roads Bridge-Tunnel Expansion Project spanned from
September 2020 through July 2021 (over a 197-day period) and monitoring for the Pier 3
Navy Construction Project spanned from August 2022 to December 2022 (i.e., over a 45-day
period) (Hampton Roads Connector Partners 2023; W.F. Magann Corporation 2023).
Bottlenose Dolphin
Along the U.S. East Coast and northern Gulf of Mexico, the bottlenose dolphin stock
structure is well studied. There are currently 54 management stocks identified by NMFS in
the western North Atlantic and Gulf of Mexico, including oceanic, coastal, and estuarine
stocks (Hayes et al., 2017; Waring et al., 2015, 2016).

Bottlenose dolphins inhabiting nearshore coastal and estuarine waters between New
York and Florida may be a separate species from their offshore counterparts (Costa et al.,
2022). The offshore form is larger in total length and skull length and has wider nasal bones
than the coastal form. Both inhabit waters in the western North Atlantic Ocean and Gulf of
Mexico (Curry and Smith, 1997; Hersh and Duffield, 1990; Mead and Potter, 1995) along the
U.S. Atlantic coast. The coastal species of bottlenose dolphin is continuously distributed
along the Atlantic coast south of Long Island, New York, around the Florida peninsula, and
along the Gulf of Mexico coast. This type typically occurs in waters less than 25 meters deep
(Waring et al., 2015). The range of the offshore bottlenose dolphin includes waters beyond
the continental slope (Kenney, 1990), and offshore bottlenose dolphins may move between
the Gulf of Mexico and the Atlantic (Wells et al., 1999).
Two coastal stocks are likely to be present in the Project Area: (1) the Western North
Atlantic Northern Migratory Coastal stock; and (2) the Western North Atlantic Southern
Migratory Coastal stock. Additionally, the Northern North Carolina Estuarine System stock
may occur in the Project Area.
Bottlenose dolphins are the most abundant marine mammal along the Virginia coast
and within the Chesapeake Bay, typically traveling in groups of 2-15 individuals, but
occasionally in groups of over 100 individuals (Engelhaupt et al., 2014; 2015; 2016).
Bottlenose dolphins of the Western North Atlantic Northern Migratory Coastal stock winter
along the coast of North Carolina and migrate as far north as Long Island, New York, in the
summer. They are rarely found north of North Carolina in the winter (NMFS, 2018). The
Western North Atlantic Southern Migratory Coastal stock occurs in waters of southern North
Carolina from October to December, moving south during winter months and north to North
Carolina during spring months. During July and August, the Western North Atlantic Southern
Migratory Coastal stock is presumed to occupy coastal waters north of Cape Lookout, North
Carolina, to the eastern shore of Virginia (NMFS, 2018). It is possible that these animals also
occur inside the Chesapeake Bay and in nearshore coastal waters. The North Carolina
Estuarine System stock dolphins may also occur in the Chesapeake Bay during July and
August (NMFS, 2018).
Vessel surveys conducted along coastal and offshore transects from NAVSTA
Norfolk to Virginia Beach in most months from August 2012 to August 2015 reported
bottlenose dolphins throughout the survey area, including the vicinity of NAVSTA Norfolk
(Engelhaupt et al., 2014; 2015; 2016). The final results from this project confirmed earlier
findings that bottlenose dolphins are common in the study area, with highest densities in the
coastal waters in summer and fall months. However, bottlenose dolphins do not completely
leave this area during colder months, with approximately 200-300 individuals still present in
winter and spring months, which is commonly referred to as the Chesapeake Bay resident
dolphin population (Engelhaupt et al., 2016). During monitoring of Pier 3 Navy Construction
Project, 18 bottlenose dolphins were observed over 45 days of construction (W.F. Magann
Corporation 2023). Over the 197 days of construction a total of 94 bottlenose dolphins were
observed during the Hampton Roads Bridge-Tunnel Expansion Project (Hampton Roads
Connector Partners 2023). For both projects bottlenose dolphins were the only marine
mammal observed while conducting monitoring activities.
Harbor Porpoise
Harbor porpoises inhabit cool temperate-to-subpolar waters, often where prey
aggregations are concentrated (Watts and Gaskin, 1985). Thus, they are frequently found in
shallow waters, most often near shore, but they sometimes move into deeper offshore waters.
Harbor porpoises are rarely found in waters warmer than 63 degrees Fahrenheit (17 degrees
Celsius) (Read 1999) and closely follow the movements of their primary prey, Atlantic
herring (Gaskin 1992).
In the western North Atlantic, harbor porpoise range from Cumberland Sound on the
east coast of Baffin Island, southeast along the eastern coast of Labrador to Newfoundland
and the Gulf of St. Lawrence, then southwest to about 34 degrees North on the coast of North
Carolina (Waring et al., 2016). 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 (Waring et al., 2016).
Harbor porpoises sighted off the mid-Atlantic during winter include porpoises from other
western North Atlantic populations (Rosel et al., 1999). There does not appear to be a
temporally coordinated migration or a specific migratory route to and from the Bay of Fundy
region (Waring et al., 2016). During the fall (October to December) and the spring (April to
June), harbor porpoises are widely dispersed from New Jersey to Maine, with lower densities
farther north and south (LaBrecque et al., 2015).
Based on stranding reports, passive acoustic recorders, and shipboard surveys, harbor
porpoise occur in coastal waters primarily in winter and spring months, but there is little
information on their presence in the Chesapeake Bay. They do not appear to be abundant in
the NAVSTA Norfolk area in most years, but this is confounded by wide variations in
stranding occurrences over the past decade. There were no harbor porpoise observed during
construction activities for the Pier 3 Navy Construction Project or the Hampton Roads
Bridge-Tunnel Expansion Project (Hampton Roads Connector Partners 2023; W.F. Magann
Corporation 2023).
Harbor Seal
The Western North Atlantic stock of harbor seals occurs in the Project Area. Harbor
seal distribution along the U.S. Atlantic coast has shifted in recent years, with an increased
number of seals reported from southern New England to the mid-Atlantic region (DiGiovanni
et al., 2011; Hayes et al., 2021). Regular sightings of seals in Virginia have become a
common occurrence in winter and early spring (Costidis et al., 2019). Winter haulout sites
for harbor seals have been documented in the Chesapeake Bay at the Chesapeake Bay Bridge
Tunnel (CBBT), on the Virginia Eastern Shore, and near Oregon Inlet, North Carolina
(Waring et al., 2016; Rees et al., 2016; Jones et al., 2018).
Harbor seals regularly haul out on rocks around the portal islands of the CBBT and
on mud flats on the nearby southern tip of the Eastern Shore from December through April
(Rees et al., 2016; Jones et al., 2018). Seals captured in 2018 on the Eastern Shore and
tagged with satellite-tracked tags that lasted from 2 to 5 months spent at least 60 days in
Virginia waters before departing the area. All tagged seals returned regularly to the capture
site while in Virginia waters, but individuals utilized offshore and Chesapeake Bay waters to
different extents (Ampela et al., 2019). The area that was utilized most heavily was near the
Eastern Shore capture site, but some seals ranged into the Chesapeake Bay. To supplement
this information, there were no harbor seals observed during construction activities for the
Pier 3 Navy Construction Project or the Hampton Roads Bridge-Tunnel Expansion Project
(Hampton Roads Connector Partners 2023; W.F. Magann Corporation 2023).
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. 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, 2019) recommended that marine mammals be
divided into hearing groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response data, anatomical
modeling, etc.). 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 decibel (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 4.
Table 4 -- Marine Mammal Hearing Groups (NMFS, 2018)
Generalized Hearing
Range*

Hearing Group

Low-frequency (LF) cetaceans
7 Hz to 35 kHz
(baleen whales)
Mid-frequency (MF) cetaceans
150 Hz to 160 kHz
(dolphins, toothed whales, beaked whales, bottlenose whales)
High-frequency (HF) cetaceans
275 Hz to 160 kHz
(true porpoises, Kogia, river dolphins, Cephalorhynchid,
Lagenorhynchus cruciger & L. australis)
Phocid pinnipeds (PW) (underwater)
50 Hz to 86 kHz
(true seals)
Otariid pinnipeds (OW) (underwater)
60 Hz to 39 kHz
(sea lions and fur seals)
* 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).
For more detail concerning these groups and associated frequency ranges, please see
NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their Habitat
This section provides a discussion of the ways in which components of the specified
activity may impact marine mammals and their habitat. The Estimated Take of Marine
Mammals section later in this document includes a quantitative analysis of the number of
individuals that are expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the Estimated Take of
Marine Mammals section, and the Proposed Mitigation section, to draw conclusions
regarding the likely impacts of these activities on the reproductive success or survivorship of
individuals and whether those impacts are reasonably expected to, or reasonably likely to,
adversely affect the species or stock through effects on annual rates of recruitment or
survival.
Description of Sound Sources
The marine soundscape is comprised of both ambient and anthropogenic sounds.
Ambient sound is defined as the all-encompassing sound in a given place and is usually a
composite of sound from many sources both near and far. The sound level of an area is
defined by the total acoustical energy being generated by known and unknown sources.
These sources may include physical (e.g., waves, wind, precipitation, earthquakes, ice,
atmospheric sound), biological (e.g., sounds produced by marine mammals, fish, and
invertebrates), and anthropogenic sound (e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at any given location
and time—which comprise “ambient” or “background” sound—depends not only on the
source levels (as determined by current weather conditions and levels of biological and
shipping activity) but also on the ability of sound to propagate through the environment. In
turn, sound propagation is dependent on the spatially and temporally varying properties of the
water column and sea floor and is frequency-dependent. As a result of the dependence on a
large number of varying factors, ambient sound levels can be expected to vary widely over
both coarse and fine spatial and temporal scales. Sound levels at a given frequency and
location can vary by 10-20 dB from day to day (Richardson et al., 1995). The result is that,
depending on the source type and its intensity, sound from the specified activity may be a
negligible addition to the local environment or could form a distinctive signal that may affect
marine mammals.
In-water construction activities associated with the Project would include vibratory
pile driving and removal and impact pile driving. The sounds produced by these activities fall
into one of two general sound types: (1) impulsive; and (2) non-impulsive. Impulsive sounds
(e.g., explosions, gunshots, sonic booms, impact pile driving) are typically transient, brief
(i.e., less than 1 second), broadband, and consist of high peak sound pressure with rapid rise
time and rapid decay (ANSI 1986; NIOSH 1998; ANSI 2005; NMFS 2018). Non-impulsive
sounds (e.g., aircraft, machinery operations such as drilling or dredging, vibratory pile
driving, and active sonar systems) can be broadband, narrowband or tonal, brief or prolonged
(continuous or intermittent), and typically do not have the high peak sound pressure with raid
rise/decay time that impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS 2018). The
distinction between these two sound types is important because they have differing potential
to cause physical effects, particularly with regard to hearing (e.g., Ward 1997 in Southall et
al., 2007).
Impact hammers operate by repeatedly dropping a heavy piston onto a pile to drive
the pile into the substrate. Sound generated by impact hammers is characterized by rapid rise
times and high peak levels, a potentially injurious combination (Hastings and Popper 2005).
Vibratory hammers install piles by vibrating them and allowing the weight of the hammer to
push them into the sediment. The vibrations produced also cause liquefaction of the substrate
surrounding the pile, enabling the pile to be extracted or driven into the ground more easily.
Vibratory hammers produce significantly less sound than impact hammers. Peak sound
pressure levels (SPLs) may be 180 dB or greater but are generally 10 to 20 dB lower than
SPLs generated during impact pile driving of the same-sized pile (Oestman et al., 2009). Rise
time is slower, reducing the probability and severity of injury, and sound energy is distributed
over a greater amount of time (Nedwell and Edwards 2002; Carlson et al., 2005).
The likely or possible impacts of the Navy's proposed activity on marine mammals
could involve both non-acoustic and acoustic stressors. Potential non-acoustic stressors could
result from the physical presence of the equipment and personnel; however, any impacts to
marine mammals are expected to be primarily acoustic in nature and no takes specifically
attributed to non-acoustic stressors are expected to occur. Acoustic stressors include effects
of heavy equipment operation during pile driving and removal.
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic environment from pile
driving is the primary means by which marine mammals may be harassed from the Navy's
specified activity. In general, animals exposed to natural or anthropogenic sound may
experience physical and psychological effects, ranging in magnitude from none to severe
(Southall et al., 2007 and Southall et al. 2021). In general, exposure to pile driving noise has
the potential to result in auditory threshold shifts and behavioral reactions (e.g., avoidance,
temporary cessation of foraging and vocalizing, changes in dive behavior). Exposure to
anthropogenic noise can also lead to non-observable physiological responses such an increase
in stress hormones. Additional noise in a marine mammal's habitat can mask acoustic cues
used by marine mammals to carry out daily functions such as communication and predator
and prey detection. The effects of pile driving noise on marine mammals are dependent on
several factors, including, but not limited to, sound type (e.g., impulsive vs. non-impulsive),
the species, age and sex class (e.g., adult male vs. mom with calf), duration of exposure, the
distance between the pile and there animal, received levels, behavior at time of exposure, and
previous history with exposure (Wartzok et al., 2004; Southall et al., 2007). Here we discuss
physical auditory effects (threshold shifts) followed by behavioral effects and potential
impacts on habitat.
NMFS defines a noise-induced threshold shift (TS) 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 (NMFS 2018). The amount of threshold
shift is customarily expressed in dB. A TS can be permanent or temporary. As described in
NMFS (2018), there are numerous factors to consider when examining the consequence of
TS, including, but not limited to, the signal temporal pattern (e.g., impulsive or nonimpulsive), likelihood an individual would be exposed for a long enough duration or to a high
enough level to induce a TS, the magnitude of the TS, time to recovery (seconds to minutes
or hours to days), the frequency range of the exposure (i.e., spectral content), the hearing and
vocalization frequency range of the exposed species relative to the signal's frequency
spectrum (i.e., how an animal uses sound within the frequency band of the signal; e.g.,
Kastelein et al., 2014), and the overlap between the animal and the source (e.g., spatial,
temporal, and spectral).
Permanent Threshold Shift (PTS)—NMFS defines PTS as a permanent, irreversible
increase in the threshold of audibility at a specified frequency or portion of an individual's
hearing range above a previously established reference level (NMFS 2018). Available data
from humans and other terrestrial mammals indicate that a 40 dB threshold shift
approximates PTS onset (see Ward et al., 1958, 1959; Ward 1960; Kryter et al., 1966; Miller
1974; Ahroon et al., 1996; Henderson et al., 2008). PTS levels for marine mammals are
estimates (with the exception of a single study unintentionally inducing PTS in a harbor seal
(Kastak et al., 2008)), and there are no empirical data measuring PTS in marine mammals
largely due to the fact that, for various ethical reasons, experiments involving anthropogenic
noise exposure at levels inducing PTS are not typically pursued or authorized (NMFS 2018).
Temporary Threshold Shift (TTS)—TTS is a temporary, reversible increase in the
threshold of audibility at a specified frequency or portion of an individual's hearing range
above a previously established reference level (NMFS 2018). Based on data from cetacean
TTS measurements (see Southall et al., 2007), a TTS of six dB is 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, 2002). As described in
Finneran (2015), marine mammal studies have shown the amount of TTS increases with
cumulative sound exposure level (SELcum) in an accelerating fashion. At low exposures
with lower SELcum, the amount of TTS is typically small and the growth curves have
shallow slopes. At exposures with higher SELcum, the growth curves become steeper and
approach linear relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration (i.e., recovery time),
and frequency range of TTS, and the context in which it is experienced, TTS can have effects
on marine mammals ranging from discountable to serious (similar to those discussed in
auditory masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-critical frequency range that
takes place during a time when the animal is traveling through the open ocean, where
ambient noise is lower and there are not as many competing sounds present. Alternatively, a
larger amount and longer duration of TTS sustained during a time when communication is
critical for successful mother/calf interactions could have more serious impacts. We note that
reduced hearing sensitivity as a simple function of aging has been observed in marine
mammals, as well as humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though likely not without cost.
Currently, TTS data only exist for four species of cetaceans (i.e., bottlenose dolphin,
beluga whale (Delphinapterus leucas), harbor porpoise, and Yangtze finless porpoise
(Neophocoena asiaeorientalis)) and five species of pinnipeds exposed to a limited number of
sound sources (i.e., mostly tones and octave-band noise) in laboratory settings (Finneran
2015). TTS was not observed in trained spotted (Phoca largha) and ringed (Pusa hispida)
seals exposed to impulsive noise at levels matching previous predictions of TTS onset
(Reichmuth et al., 2016). In general, harbor seals and harbor porpoises have a lower TTS
onset than other measured pinniped or cetacean species (Finneran 2015). Additionally, the
existing marine mammal TTS data come from a limited number of individuals within these
species. No data are available on noise-induced hearing loss for mysticetes. For summaries of
data on TTS in marine mammals or for further discussion of TTS onset thresholds, please see
Southall et al. (2007), Finneran and Jenkins (2012), Finneran (2015), and table 5 in NMFS
(2018).
Installing piles for this Project requires a combination of impact pile driving and
vibratory pile driving. For this Project, these activities would not occur at the same time and
there would be pauses in activities producing the sound during each day. Given these pauses
and that many marine mammals are likely moving through the ensonified area and not
remaining for extended periods of time, the potential for TS declines.
Behavioral Effects
Exposure to noise from pile driving and removal also has the potential to behaviorally
disturb marine mammals. Available studies show wide variation in response to underwater
sound; therefore, it is difficult to predict specifically how any given sound in a particular
instance might affect marine mammals perceiving the signal. If a marine mammal does react
briefly to an underwater sound by changing its behavior or moving a small distance, the
impacts of the change are unlikely to be significant to the individual, let alone the stock or
population. However, if a sound source displaces marine mammals from an important
feeding or breeding area for a prolonged period, impacts on individuals and populations
could be significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007; NRC, 2005; Southall et
al., 2021).
Disturbance may result in: (1) changing durations of surfacing and dives, number of
blows per surfacing, or moving direction and/or speed; (2) reduced/increased vocal activities;
(3) changing/cessation of certain behavioral activities (e.g., socializing or feeding); (4) visible
startle response or aggressive behavior (e.g., tail/fluke slapping or jaw clapping); (5)
avoidance of areas where sound sources are located. Pinnipeds may increase their haul out
time, possibly to avoid in-water disturbance (Thorson and Reyff, 2006). Behavioral responses
to sound are highly variable and context-specific, and any reactions depend on numerous
intrinsic and extrinsic factors (e.g., species, state of maturity, experience, current activity,
reproductive state, auditory sensitivity, time of day), as well as the interplay between those
factors (e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007, Southall et
al. 2021; Weilgart, 2007; Archer et al., 2010). Behavioral reactions can vary not only among
individuals but also within exposures of an individual, depending on previous experience
with a sound source, context, and numerous other factors (Ellison et al., 2012; Southall et al.,
2021), and can vary depending on characteristics associated with the sound source (e.g.,
whether it is moving or stationary, number of sources, distance from the source). In general,
pinnipeds seem more tolerant of, or at least habituate more quickly to, potentially disturbing
underwater sound than do cetaceans, and generally seem to be less responsive to exposure to
industrial sound than most cetaceans. For a review of studies involving marine mammal
behavioral responses to sound, see: Southall et al., 2007; Gomez et al., 2016; and Southall et
al., 2021.

Disruption of feeding behavior can be difficult to correlate with anthropogenic sound
exposure, so it is usually inferred by observed displacement from known foraging areas, the
appearance of secondary indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency, duration, and temporal
pattern of signal presentation, as well as differences in species sensitivity, are likely
contributing factors to differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al., 2007). A determination of
whether foraging disruptions incur fitness consequences would require information on or
estimates of the energetic requirements of the affected individuals and the relationship
between prey availability, foraging effort and success, and the life history stage of the animal.
In 2021, the Navy monitored construction activities at Pier 3 during pile driving
activities from August through December. That project was in roughly the same location as
the Q8 bulkhead. Four detections of 35 bottlenose dolphins occurred over 45 total days of
construction. All 35 of the bottlenose dolphins that were observed were in estimated Level B
harassment zones and occurred just in the month of August (W.F. Magann Corporation
2023). The I-64 Hampton Roads Bridge-Tunnel Expansion Project pile driving occurred from
January through December of 2023 over 234 days. During that work, 94 bottlenose dolphins
were observed entering harassment zones (92 in estimated Level B harassment zones and two
in estimated Level A harassment zones) (Hampton Roads Connector Partners 2023). During
both of these projects, the only marine mammals observed were bottlenose dolphins and no
visible signs of disturbance were noted for any of the dolphins. Given the similarities in
activities and habitat and the fact the same species are involved, we expect similar behavioral
responses of marine mammals to the specified activity. That is, disturbance, if any, is likely
to be temporary and localized (e.g., small area movements).

Airborne Acoustic Effects—Although pinnipeds are known to haul-out regularly on
man-made objects (e.g., the CBBT), we believe that incidents of take resulting solely from
airborne sound are unlikely due to the sheltered proximity between the proposed Project Area
and these haulout sites (i.e., over 16 miles (26 km)). There is a possibility that an animal
could surface in-water, but with head out, within the area in which airborne sound exceeds
relevant thresholds and thereby be exposed to levels of airborne sound that we associate with
harassment, but any such occurrence would likely be accounted for in our estimate of
incidental take from underwater sound. Therefore, authorization of incidental take resulting
from airborne sound for pinnipeds is not warranted, and airborne sound is not discussed
further here. Cetaceans are not expected to be exposed to airborne sounds that would result in
harassment as defined under the MMPA.
Marine Mammal Habitat Effects
The Navy's construction activities could have localized, temporary impacts on marine
mammal habitat by increasing in-water sound pressure levels and slightly decreasing water
quality. However, since the focus of the proposed action is pile driving, no net habitat loss is
expected as the new Q8 bulkhead would be immediately seaward of the existing bulkhead or
would encapsulate the existing bulkhead. Construction activities are of short duration and
would likely have temporary impacts on marine mammal habitat through increases in
underwater sounds. Increased noise levels may affect the acoustic habitat and adversely
affect marine mammal prey in the vicinity of the Project Area (see discussion below). During
pile driving activities, elevated levels of underwater noise would ensonify the Project Area
where both fishes and marine mammals may occur and could affect foraging success.
Additionally, marine mammals may avoid the area during construction, however
displacement due to noise is expected to be temporary and is not expected to result in longterm effects to the individuals or populations. The area likely impacted by the Project is
relatively small compared to the available habitat in the surrounding waters of the
Chesapeake Bay.
Temporary and localized reduction in water quality will occur because of in-water
construction activities as well. Most of this effect will occur during the installation and
removal of piles when bottom sediments are disturbed. The installation of piles will disturb
bottom sediments and may cause a temporary increase in suspended sediment in the Project
Area. In general, turbidity associated with pile installation is localized to an approximately
25-ft (7.6 m) radius around the pile (Everitt et al., 1980). Cetaceans are not expected to be
close enough to the pile driving areas to experience effects of turbidity, and any pinnipeds
could avoid localized areas of turbidity. Therefore, we expect the impact from increased
turbidity levels to be discountable to marine mammals and do not discuss it further.
In-Water Construction Effects on Potential Foraging Habitat— The proposed
activities would not result in permanent impacts to habitats used directly by marine mammals
except for the actual footprint of the new Q8 bulkhead. The total seafloor area affected by
pile installation and removal is a very small area that is not known to be of particular
importance compared to the vast foraging area available to marine mammals in the Project
Area and lower Chesapeake Bay. Pile extraction and installation may have impacts on
benthic invertebrate species primarily associated with disturbance of sediments that may
cover or displace some invertebrates. The impacts will be temporary and highly localized,
and no habitat will be permanently displaced by construction. Therefore, it is expected that
impacts on foraging opportunities for marine mammals due to the construction of the Q8
bulkhead would be minimal.
It is possible that avoidance by potential prey (i.e., fish) in the immediate area may
occur due to temporary loss of this foraging habitat. The duration of fish avoidance of this
area after pile driving stops is unknown, but we anticipate a rapid return to normal
recruitment, distribution, and behavior. Any behavioral avoidance by fish of the disturbed
area would still leave large areas of fish and marine mammal foraging habitat in the nearby
vicinity in the Project Area and lower Chesapeake Bay.
Effects on Potential Prey—Sound may affect marine mammals through impacts on
the abundance, behavior, or distribution of prey species (e.g., fish). Marine mammal prey
varies by species, season, and location. Here, we describe studies regarding the effects of
noise on known marine mammal prey.
Fish utilize the soundscape and components of sound in their environment to perform
important functions such as foraging, predator avoidance, mating, and spawning (e.g., Zelick
et al., 1999; Fay, 2009). Depending on their hearing anatomy and peripheral sensory
structures, which vary among species, fish hear sounds using pressure and particle motion
sensitivity capabilities and detect the motion of surrounding water (Fay
et al., 2008). The potential effects of noise on fishes depend on the overlapping frequency
range, distance from the sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include behavioral
responses, hearing damage, pressure-related injuries (i.e., barotrauma ), and mortality.
Fish react to sounds which are especially strong and/or intermittent low-frequency
sounds, and behavioral responses such as flight or avoidance are the most likely effects. Short
duration, sharp sounds can cause overt or subtle changes in fish behavior and local
distribution. The reaction of fish to noise depends on the physiological state of the fish, past
exposures, motivation (e.g., feeding, spawning, migration), and other environmental factors.
Hastings and Popper (2005) identified several studies that suggest fish may relocate to avoid
certain areas of sound energy. Additional studies have documented effects of pile driving on
fish, although several are based on studies in support of large, multiyear bridge construction
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 2009). Several studies
have demonstrated that impulse sounds might affect the distribution and behavior of some
fishes, potentially impacting foraging opportunities or increasing energetic costs (e.g.,
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al., 1992; Santulli et al., 1999;
Paxton et al., 2017). However, some studies have shown no or slight reaction to impulse
sounds (e.g., Pena et al., 2013; Wardle et al., 2001; Jorgenson and Gyselman, 2009; Cott et
al., 2012).
SPLs of sufficient strength have been known to cause injury to fish and fish
mortality. However, in most fish species, hair cells in the ear continuously regenerate and
loss of auditory function likely is restored when damaged cells are replaced with new cells.
Halvorsen et al. (2012a) showed that a TTS of 4-6 dB was recoverable within 24 hours for
one species. Impacts would be most severe when the individual fish is close to the source and
when the duration of exposure is long. Injury caused by barotrauma can range from slight to
severe and can cause death and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile driving (Halvorsen
et al., 2012b; Casper et al., 2013).
The most likely impact to fish from pile driving activities in the Project Area would
be temporary behavioral avoidance of the area. The duration of fish avoidance of an area
after pile driving stops is unknown, but a rapid return to normal recruitment, distribution and
behavior is anticipated.
The area impacted by the Project is relatively small compared to the available habitat
in the remainder of the Project Area and the lower Chesapeake Bay, and there are no areas of
particular importance that would be impacted by this Project. Any behavioral avoidance by
fish of the disturbed area would still leave significantly large areas of fish and marine
mammal foraging habitat in the nearby vicinity. As described in the preceding, the potential
for the Navy's construction to affect the availability of prey to marine mammals or to
meaningfully impact the quality of physical or acoustic habitat is considered to be
insignificant.
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes proposed for
authorization, which will inform both NMFS’ consideration of “small numbers,” and the
negligible impact determinations.
Harassment is the only type of take expected to result from these activities. Except
with respect to certain activities not pertinent here, section 3(18) of the MMPA defines
“harassment” as any act of pursuit, torment, or annoyance, which (i) has the potential to
injure a marine mammal or marine mammal stock in the wild (Level A harassment); or (ii)
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 (Level B harassment) (16 U.S.C. 1362(18)(A)(i)-(ii)).
Authorized takes would be by Level B harassment only, in the form of disruption of
behavioral patterns for individual marine mammals resulting from exposure to sounds
emitted from pile driving. Based on the nature of the activity and the anticipated
effectiveness of the mitigation measures (i.e., shutdown zones) discussed in detail below in
the Proposed Mitigation section, Level A harassment is neither anticipated nor proposed to
be authorized.
As described previously, no serious injury or mortality is anticipated or proposed to
be authorized for this activity. Below we describe how the proposed take numbers are
estimated.
For acoustic impacts, 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; (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 factors can contribute to a basic
calculation to provide an initial prediction of potential takes, additional information that can
qualitatively inform take estimates is also sometimes available (e.g., previous monitoring
results or average group size). Below, we describe the factors considered here in more detail
and present the proposed take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the received level of
underwater sound above which exposed marine mammals would be reasonably expected to
be behaviorally harassed (equated to Level B harassment) or to incur PTS of some degree
(equated to Level A harassment).
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., bathymetry, other noises in the area, predators 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 root-mean-squared pressure received levels (RMS
SPL) of 120 dB (referenced to one micropascal (re one μPa)) for continuous (e.g., vibratory
pile driving) and above RMS SPL 160 dB re one μPa for non-explosive impulsive (e.g.,
seismic airguns) or intermittent (e.g., scientific sonar) sources. 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 (i.e., conspecific communication,
predators, and prey) may result in changes in behavior patterns that would not otherwise
occur.
The Navy’s activity includes the use of continuous (e.g., vibratory pile driving and
removal) and impulsive (e.g., impact pile driving) sources, and therefore the RMS SPL
thresholds of 120 and 160 dB re one μPa are applicable.
These thresholds are provided in table 5 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 5 -- Thresholds Identifying the Onset of Permanent Threshold Shift.

Hearing Group
Low-Frequency (LF)
Cetaceans
Mid-Frequency (MF)
Cetaceans

PTS Onset Acoustic Thresholds*
(Received Level)
Impulsive
Non-impulsive
Cell 1
Cell 2
Lpk,flat: 219 dB
LE,LF,24h: 199 dB
LE,LF,24h: 183 dB
Cell 3
Cell 4
Lpk,flat: 230 dB
LE,MF,24h: 198 dB
LE,MF,24h: 185 dB

Cell 5
Cell 6
Lpk,flat: 202 dB
LE,HF,24h: 173 dB
LE,HF,24h: 155 dB
Cell 7
Cell 8
Phocid Pinnipeds (PW)
Lpk,flat: 218 dB
LE,PW,24h: 201 dB
(Underwater)
LE,PW,24h: 185 dB
Cell 9
Cell 10
Otariid Pinnipeds (OW)
Lpk,flat: 232 dB
LE,OW,24h: 219 dB
(Underwater)
LE,OW,24h: 203 dB
* Dual metric acoustic 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 should also be considered.
High-Frequency (HF)
Cetaceans

Note: Peak sound pressure (Lpk) has a reference value of one 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, peak sound pressure is defined by ANSI as incorporating frequency weighting,
which is not the intent for this Technical Guidance. Hence, the subscript “flat” is included
to indicate peak sound pressure should be flat weighted or unweighted within the
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 and OW 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.
Ensonified Area
Here, we describe operational and environmental parameters of the activity that are
used in estimating the area ensonified above the acoustic thresholds, including source levels
and transmission loss coefficient.
The sound field in the Project Area is the existing background noise plus additional
construction noise from the proposed Project. Marine mammals are expected to be affected
via sound generated by the primary components of the Project (i.e., impact pile driving and
vibratory pile driving and removal). The maximum underwater area ensonified above the
thresholds for individual activities of behavioral harassment referenced above is 93.5 km2
(36.1 mi2) and would consist of an area reaching the opposite shoreline of the river (see

figures 6.6, 6.8, and 6.10 in the Navy’s application for the Incidental Take Authorization for
the Q8 bulkhead Project). The maximum (underwater) area ensonified above the thresholds
for concurrent activities of behavioral harassment referenced above is 97.9 km2 (37.8 mi2)
and would consist of a similar area reaching the opposite shoreline of the river as individual
activities (see figures 6.11-6.16 in the Navy’s application). Additionally, vessel traffic and
other commercial and industrial activities in the Project Area may contribute to elevated
background noise levels which may mask sounds produced by the Project.
Transmission loss (TL) is the decrease in acoustic intensity as an acoustic pressure
wave propagates out from a source. TL parameters vary with frequency, temperature, sea
conditions, current, source and receiver depth, water depth, water chemistry, and bottom
composition and topography. The general formula for underwater TL is:
TL = B * Log10 (R1/R2), where
TL = transmission loss in dB
B = transmission loss coefficient
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement
This formula neglects loss due to scattering and absorption, which is assumed to be
zero here. The degree to which underwater sound propagates away from a sound source is
dependent on a variety of factors, most notably the water bathymetry and presence or absence
of reflective or absorptive conditions including in-water structures and sediments. Spherical
spreading occurs in a perfectly unobstructed (i.e., 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*log[range]). Cylindrical spreading occurs in an environment in
which sound propagation is bounded by the water surface and sea bottom, resulting in a
reduction of three dB in sound level for each doubling of distance from the source
(10*log[range]). A practical spreading value of 15 is often used under conditions, such as the
Project site, where water increases with depth as the receiver moves away from the shoreline,
resulting in an expected propagation environment that would lie between spherical and
cylindrical spreading loss conditions. Practical spreading loss is assumed here.
The intensity of pile driving sounds is greatly influenced by factors such as the type
of piles, hammers, and the physical environment in which the activity takes place. In order to
calculate the distances to the Level A harassment and the Level B harassment sound
thresholds for the methods and piles being used in this Project, the Navy and NMFS used
acoustic monitoring data from other locations to develop proxy source levels for the various
pile types, sizes, and methods. The Project includes vibratory and impact installation of
prestressed concrete and composite piles and vibratory removal of existing concrete piles.
Steel sheet piles to make up the wall of the bulkhead would be installed with vibratory
hammers. Source levels for each pile size and driving method for individual activities are
presented in table 6. For concurrent activities where two noise sources have overlapping
sound fields, there is potential for higher sound levels than for non-overlapping sources
because the isopleth of one sound source encompasses the sound source of another isopleth.
In such instances, the sources are considered additive and combined using the rules of decibel
addition. For addition of two simultaneous sources, the difference between the two sound
source levels is calculated, and: (1) if that difference is between zero and one dB, three dB
are added to the higher sound source level; (2) if the difference is between two or three dB,
two dB are added to the highest sound source level; (3) if the difference is between four to
nine dB, one dB is added to the highest sound source level; and (4) with differences of 10 dB
or more, there is no addition. Source levels for each pile size and vibratory driving for
concurrent activities are presented in table 7.
Table 6 -- Proxy Sound Source Levels for Pile Sizes and Driving Methods
Proxy Source Level
Pile Size

Method

56-in sheet
pile

Literature source

dB RMS
re 1µPa

dB SEL re
1µPa2sec

dB peak
re 1µPa

Vibratory

N/A

N/A

Illingworth and
Rodkin, 2017

18-in
concrete

Vibratory

N/A

N/A

Caltrans, 2020

16-in
composite

Vibratory

N/A

N/A

Illingworth and
Rodkin, 2017

18-in
concrete

Impact

160

e4sciences, 2023

16-in
composite

Impact

157

Illingworth and
Rodkin, 2017

Table 7 -- Proxy Sound Source Levels for concurrent activities
Pile Size and Type

Vibratory
Vibratory
Revised SL to
Installation Source Extract Source 2 be used [dB
1 [dB RMS]
[dB RMS]
RMS]

Source 1: Vibratory hammer 56inch steel sheet pile; Source 2:
Vibratory extraction of 18-inch
concrete pile

162

Source 1: Vibratory hammer 18inch concrete pile; Source 2:
Vibratory extraction of 18-inch
concrete pile

162

Source 1: Vibratory hammer 56inch steel sheet pile; Source 2: 16
in composite pile

158

The ensonified area associated with Level A harassment is more technically
challenging to predict due to the need to account for a duration component. Therefore, NMFS
developed an optional User Spreadsheet tool to accompany the Technical Guidance that can
be used to relatively simply predict an isopleth distance for use in conjunction with marine
mammal density or occurrence to help predict potential takes. We note that because of some
of the assumptions included in the methods underlying this optional tool, we anticipate that
the resulting isopleth estimates are typically going to be overestimates of some degree, which
may result in an overestimate of potential take by Level A harassment. However, this
optional tool offers the best way to estimate isopleth distances when more sophisticated
modeling methods are not available or practical. For stationary sources impact or vibratory
pile driving and removal, the optional User Spreadsheet tool predicts the distance at which, if
a marine mammal remained at that distance for the duration of the activity, it would be
expected to incur PTS. Inputs used in the optional User Spreadsheet tool, and the resulting
estimated isopleths, are reported below. For concurrent activities where combined impact and
vibratory hammer scenarios shown in table 10, the estimated Level A isopleth distances
reflect the impact driving activity and the estimated Level B isopleth distances reflect the
combined vibratory source levels for that activity.
Table 8 -- User Spreadsheet Input Parameters Used for Calculating Level A
Harassment Isopleths
Phase
(Year)

Phase 1
(Year 1)

Pile size
and
installation
method

Spreadsheet
tab used

Weighting
factor
adjustment
(kHz)

Number
of
strikes
per pile

Number
of piles
per day

Activity
duration
(minutes)

18-in
concrete
impact
installation

E.1 Impact
pile driving

307

N/A

Phase II
(Year 2)

Phase III
(Year 3)

18-in
concrete
vibratory
extraction

A.1
Vibratory
pile driving

2.5

N/A

14

56-in sheet
pile
vibratory
installation

A.1
Vibratory
pile driving

2.5

N/A

24

18-in
concrete
impact
installation

E.1 Impact
pile driving

499

N/A

18-in
concrete
vibratory
extraction

A.1
Vibratory
pile driving

2.5

N/A

26

56-in sheet
pile
vibratory
installation

A.1
Vibratory
pile driving

2.5

N/A

28

16-in
composite
impact
installation

E.1 Impact
pile driving

540

N/A

18-in
concrete
vibratory
installation

E.1 Impact
pile driving

540

N/A

16-in
composite
vibratory
extraction

A.1
Vibratory
pile driving

2.5

N/A

20

56-in sheet
pile
vibratory
installation

A.1
Vibratory
pile driving

2.5

N/A

38

Table 9 -- Calculated Level A and Level B Harassment Isopleths for Individual
Activities
Level A harassment zone (m)
Phase (Year)

Phase 1 (Year 1)

Phase II (Year 2)

LFcetaceans

MFcetaceans

HFcetaceans

Phocids

Level B
harassment
zone (m)

18-in concrete impact
installation

43.9

1.6

52.3

23.5

46.4

18-in concrete vibratory
extraction

10.0

0.9

14.7

6.1

6,310

56-in sheet pile vibratory
installation

35.9

3.2

53.0

21.8

15,849

18-in concrete impact
installation

60.8

2.2

72.4

32.5

46.4

18-in concrete vibratory
extraction

15.1

1.3

22.3

9.2

6,310

56-in sheet pile vibratory
installation

39.7

3.2

58.7

24.2

15,849

16-in composite impact
installation

40.4

1.4

48.1

21.6

39.8

18-in concrete impact
installation

64.0

2.3

76.3

34.3

46.4

16-in composite vibratory
extraction

6.8

0.6

10.1

4.2

3,415

56-in sheet pile vibratory
installation

48.7

4.3

72.0

29.6

15,849

Activity

Phase III (Year 3)

Table 10 -- Calculated Level A and Level B Harassment Isopleths for Concurrent
Activities

Level A harassment zone (m)1
Phase (Year)

LFcetaceans

MFcetaceans

HFcetaceans

Phocids

Level B
harassment
zone (m)

Vibratory extract 18-in
concrete piles and
vibratory install 56-in
steel sheet piles

41.8

3.7

61.8

25.4

18,478

Vibratory extract 18-in
concrete piles; vibratory
install 56-in steel sheet
piles; impact install 18-in
concrete piles

43.9

1.6

52.3

23.5

18,478

Vibratory extract 18-in
concrete piles and
vibratory install 56-in
steel sheet piles

46.3

4.1

68.5

28.2

18,478

Vibratory install 56-in
steel sheet piles and
impact install 18-in
concrete piles

60.8

2.2

72.4

32.5

15,849

Vibratory extract 18-in
concrete piles and
vibratory install 56-in
steel sheet piles

56.8

5.0

84.0

34.5

18,478

Vibratory install 56-in
steel sheet piles and
impact install 16-in
composite piles

40.4

1.4

48.1

21.6

15,849

Activity

Phase 1 (Year 1)

Phase II (Year 2)

Phase III (Year 3)

The maximum distance to the Level A harassment threshold during construction
would be during the impact driving of 18-inch (in) concrete piles during Phase III of
individual activities (i.e., 64.0 m for humpback whale) and during the concurrent vibratory
extraction of 18-in concrete piles, vibratory installation of 56-in steel sheet piles, and impact
install 18-in concrete piles for concurrent activities of Phase I (i.e., 5.4 m for bottlenose
dolphin; 89.8 m for harbor porpoises; and 36.9 m for pinnipeds). Given these relatively small
isopleths, if a marine mammal enters the shutdown zone during impact pile driving it is
expected that the construction activity would be shut down before any marine mammal
would incur PTS. Therefore, no take by Level A harassment is expected during the
construction activities associated with the Q8 bulkhead. The largest calculated Level B
harassment isopleth extends out to 18,478 m, which would result from concurrent pile
driving of the scenarios presented in table 9. The largest Level B harassment zone of 18,478
m is not an attainable observable distance in all directions, but in some areas the distance is
smaller due to the zone being cut off by landmasses. The Level B harassment zone will be
monitored to the maximum extent possible.
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of marine mammals,
including density or other relevant information which will inform the take calculations. We
describe how the information provided is synthesized to produce a quantitative estimate of
the take that is reasonably likely to occur and proposed for authorization.
Humpback Whale
Humpback whales occur in the mouth of the Chesapeake Bay and nearshore waters of
Virginia during winter and spring months. Several satellite tagged humpback whales were
detected west of the Chesapeake Bay Bridge Tunnel, including two individuals with locations
near NAVSTA Norfolk and Joint Expeditionary Base Little Creek (Aschettino et al., 2017).
Group size was not reported in these surveys; however, most whales detected were juveniles.
Although two individuals were detected in the vicinity of the proposed Project Area during
shipboard surveys conducted in 2020, there is no evidence that they lingered for multiple
days (Aschettino, 2020). Because no density estimates are available for the species in this
area, the Navy estimated, and NMFS concurs, that one potential sighting of an average size
group (i.e., two individuals) could occur every 60 days of pile driving. Therefore, given the
number of Project days expected in each year (table 1), NMFS is proposing to authorize a
total of 16 takes by Level B harassment of humpback whale over the 5-year authorization,
with no more than four takes by Level B harassment in a given year.
The largest Level A harassment zone for low-frequency cetaceans extends
approximately 64 m from the source during impact pile driving of the 18-in concrete piles
(table 9). The Navy plans to shut down if a humpback whale is sighted within any of the
Level A harassment zones for all activities. Therefore, NMFS is not proposing to authorize
take by Level A harassment of humpback whales.
Bottlenose Dolphins
The expected number of bottlenose dolphins in the Project Area was estimated using
inshore seasonal densities provided in Engelhaupt et al. (2016) from vessel line-transect
surveys near NAVSTA Norfolk and adjacent areas near Virginia Beach, Virginia, from
August 2012 through August 2015. This density includes sightings inshore of the Chesapeake
Bay from NAVSTA Norfolk west to the Thimble Shoals Bridge and is the most
representative density for the Project Area. To calculate potential Level B harassment takes
of bottlenose dolphin, NMFS conservatively multiplied the density of 1.38 dolphin/km2
(from Engelhaupt et al., 2016) by the largest Level B harassment isopleth for each activity
(tables 9 and 10), and then by the number of days associated with that activity (table 1). For
example, to calculate Level B harassment takes associated with work at the Q8 bulkhead in
Phase I for the vibratory removal of 18-in concrete piles, NMFS multiplied the density (i.e.,
1.38 dolphins/km2) by the Level B harassment zone for that activity (i.e., 43.3 km2) by the
proportional number of pile driving days for that activity (i.e., 24 days) for a total of 1,437
Level B harassment takes for that activity during Phase I. Takes by Level B harassment were
calculated for both individual pile driving activities and concurrent pile driving activities, as
authorized takes are conservatively based on the scenario that produces more takes by Level
B harassment (table 11). Therefore, NMFS proposes to authorize 14,191 takes by Level B
harassment of bottlenose dolphin across all 5 years, with no more than 6,168 takes in a given
year.
The largest Level A harassment zone for mid-frequency cetaceans extends
approximately 5.4 m from the source during concurrent activities during Phase I (table 10). A
minimum shutdown zone of 10 m would be established for all construction activities. The
Navy plans to shut down all activities if a bottlenose dolphin is sighted within the shutdown
zones for mid-frequency cetaceans. Therefore, NMFS is not proposing to authorize take by
Level A harassment of bottlenose dolphins.
Harbor Porpoise
Harbor porpoises are known to occur in the coastal waters near Virginia Beach
(Hayes et al., 2019). Density data for this species within the Project vicinity do not exist or
were not calculated because sample sizes were too small to produce reliable estimates of
density. Harbor porpoise sighting data collected by the Navy near NAVSTA Norfolk and
Virginia Beach from 2012 to 2015 (Engelhaupt et al. 2014; 2015; 2016) did not produce
enough sightings to calculate densities. One group of two harbor porpoises was seen during
spring 2015 (Engelhaupt et al. 2016). Elsewhere in their range, harbor porpoises typically
occur in groups of two to three individuals (Carretta et al. 2001; Smultea et al. 2017).
Due to there being no density estimates for the species in the Project Area, the Navy
conservatively estimated one exposure of two porpoises for every 60 days of pile driving.
Total pile driving days for Phase I would be 74 days, Phase II would be 37 days, and Phase
III would be 101 days. Takes by Level B harassment were calculated for both individual pile
driving activities and concurrent pile driving activities, as authorized takes are conservatively
based on the scenario that produced the larger exposure estimate (table 11). Using the above
methodology, NMFS calculated an exposure estimate of eight incidents of take for harbor
porpoises.
NMFS does not expect any Level A harassment of harbor porpoise during this
Project. The largest Level A harassment zone for high-frequency cetaceans extends
approximately 89.8 m from the source during concurrent activities during Phase I (table 10).
The Navy plans to shut down all activities if a harbor porpoise is sighted within the shutdown
zones for high-frequency cetaceans. Therefore, NMFS is not proposing to authorize take by
Level A harassment of harbor porpoise.
Harbor Seal
The expected number of harbor seals in the Project Area was estimated using
systematic land- and vessel-based survey data for in-water and hauled out seals collected by
the U.S. Navy at the CBBT rock armor and portal islands from 2014 through 2019 (Jones et
al., 2020). The average daily seal count from the field season ranged from eight to 23 seals,
with an average of 13.6 harbor seals across all the field seasons.
NMFS expects that harbor seals are likely to be present from November to April and,
consistent with other recent projects (88 FR 31633, May 18, 2023; 87 FR 15945, March 31,
2022; 86 FR 24340; May 6, 2021, and 86 FR 17458; April 2, 2021), NMFS calculated take
by Level B harassment by multiplying 13.6 seals by the maximum number of pile driving
days expected to occur from November through April. Therefore, we expect the total number
of takes by Level B harassment for harbor seals to be 2,882.
NMFS does not expect any Level A harassment of harbor seals during this Project.
The largest Level A harassment zone for phocids extends approximately 36.9 m from the
source during concurrent activities during Phase I (table 10). The Navy plans to shut down all
activities if a harbor porpoise is sighted within the shutdown zones for phocids. Therefore,
NMFS is not proposing to authorize take by Level A harassment of harbor seals.
Table 11 -- Proposed Authorized Takes by Level B Harassment by Species and Stock in
Comparison to Stock Abundance
LOA
Construction
Phase (Year)

Phase 1

Species

Level B
(Individual
activities)

Level B
(Concurrent
activities)

Total

Stock
Percentage
Abundance of Stock

Humpback

2

1,396

<1

Bottlenose
dolphin –
Northern
Migratory
(NM) 1, 2

2,607

6,639

39.27

Bottlenose
dolphin –
Southern
Migratory
(SM) 1, 2

2,607

3,751

69.50

823

24.30

5,414

2,888

Bottlenose
dolphin - NC
Estuarine1, 2
Harbor
porpoise

2

85,765

<1

Harbor seal

1,006

1,006

61,336

1.64

Humpback

2

1,396

<1

1,205

6,639

18.15

1,205

3,751

32.12

823

24.30

85,765

<1

Bottlenose
dolphin NM1, 2
Phase 2

Bottlenose
dolphin SM1, 2

2,609

2,179

Bottlenose
dolphin - NC
Estuarine1, 2
Harbor
porpoise

2

Harbor seal

653

61,336

1.06

Humpback

2

1,396

<1

3,256

6,639

49.04

3,256

3,751

85.80

823

24.30

Bottlenose
dolphin NM1, 2

Phase 3

Bottlenose
dolphin SM1, 2

6,168

6,712

Bottlenose
dolphin - NC
Estuarine1, 2

1Take

Harbor
porpoise

2

85,765

<1

Harbor seal

1,236

1,373

61,336

2.24

estimates are weighted based on the assumed percentages of population for each

distinct stock, those percentages were also used to predict the proportion of animals present
in the Project Area from each stock. Please see Small Numbers section for additional
information.
2Assumes

multiple repeated takes of the same individuals. Please see Small Numbers section

for additional information.
Proposed Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA, NMFS must set
forth the permissible methods of taking pursuant to the activity, and other means of effecting
the least practicable impact on the species or stock and its habitat, paying particular attention
to rookeries, mating grounds, and areas of similar significance. NMFS regulations require
applicants for incidental take authorizations to include information about the availability and
feasibility (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, NMFS considers 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 (probability of accomplishing the mitigating result if
implemented as planned), the likelihood of effective implementation (probability
implemented as planned), and;
(2) The practicability of the measures for applicant implementation, which may
consider such things as cost, impact on operations.
In addition to the measures described later in this section, the Navy will employ the
following mitigation measures:
•

The Navy will conduct briefings between construction supervisors and crews, the

marine mammal monitoring team, and Navy staff prior to the start of all pile driving activity
and when new personnel join the work, to explain responsibilities, communication
procedures, marine mammal monitoring protocol, and operational procedures;
•

If a marine mammal comes within 10 m of construction activities, including in-water

heavy machinery work, operations shall cease and vessels shall reduce speed to the minimum
level required to maintain steerage and safe working conditions;

•

Pile driving activity must be halted upon observation of either a species for which

incidental take is not authorized or a species for which incidental take has been authorized
but the authorized number of takes has been met, entering or is within the harassment zone.
The following mitigation measures apply to the Navy's in-water construction
activities.
Establishment of Shutdown Zones—The Navy will establish shutdown zones for all
pile driving and removal activities. The purpose of a shutdown zone is generally to define an
area within which shutdown of the activity would occur upon sighting of a marine mammal
(or in anticipation of an animal entering the defined area). Shutdown zones will vary based
on the activity type and marine mammal hearing group (tables 12 and 13).
Protected Species Observers (PSOs)—The placement of PSOs during all pile driving
and removal activities (described in the Proposed Monitoring and Reporting section) will
ensure that the entire shutdown zone is visible. A minimum of two PSOs would be used
during all activities.
Monitoring for Level A and B Harassment—The Navy will monitor the Level B
harassment zones (i.e., areas where SPLs are equal to or exceed the 160 dB rms threshold for
impact pile driving, and the 120 dB rms threshold during vibratory pile driving and removal)
to the extent practicable, and all of the Level A harassment zones and shutdown zones,
during all pile driving days. Monitoring zones provide utility for observing by establishing
monitoring protocols for areas adjacent to the shutdown zones. Monitoring zones enable
observers to be aware of and communicate the presence of marine mammals in the Project
Area outside the shutdown zone and thus prepare for a potential cessation of activity should
the animal enter the shutdown zone.

Pre-Activity Monitoring—Prior to the start of daily in-water construction activity, or
whenever a break in pile driving/removal of 30 minutes or longer occurs, PSOs will observe
the shutdown and monitoring zones for a period of 30 minutes. Pile driving may commence
following 30 minutes of observation when the determination is made that the shutdown zones
are clear of marine mammals. If a marine mammal is observed within the shutdown zones
listed in table 12 or table 13, pile driving activity must be delayed or halted. If pile driving is
delayed or halted due to the presence of a marine mammal, the activity may not commence or
resume until either the animal has voluntarily exited and been visually confirmed beyond the
shutdown zones or 15 minutes have passed without re-detection of the animal. If work ceases
for more than 30 minutes, the pre-activity monitoring of the shutdown zones will commence.
A determination that the shutdown zone is clear must be made during a period of good
visibility (i.e., the entire shutdown zone and surrounding waters must be visible to the naked
eye).
Soft Start—Soft start procedures are used to provide additional protection to marine
mammals by providing warning and/or giving marine mammals a chance to leave the area
prior to the hammer operating at full capacity. For impact pile driving, contractors will be
required to provide an initial set of three strikes from the hammer at reduced energy,
followed by a 30-second waiting period, then two subsequent reduced-energy strike sets. Soft
starts will be implemented at the start of each day's impact pile driving and at any time
following cessation of impact pile driving for a period of 30 minutes or longer.
Table 12 -- Proposed Shutdown and Monitoring Zones for Individual Activities
Proposed Shutdown Zones (m)
Phase (Year)

Activity

LFcetaceans

HFcetaceans

All other
marine
mammals

Level B
monitoring
zones all
marine
mammals

Phase 1 (Year 1)

Phase II (Year 2)

18-in concrete impact
installation

60

50

18-in concrete vibratory
extraction

20

6,310

56-in sheet pile vibratory
installation

60

15,850

18-in concrete impact
installation

80

50

18-in concrete vibratory
extraction

30

6,310

56-in sheet pile vibratory
installation

60

15,850

16-in composite impact
installation

50

40

18-in concrete impact
installation

80

50

16-in composite
vibratory extraction

20

3,415

56-in sheet pile vibratory
installation

80

15,850

Phase III (Year 3)

Table 13 -- Proposed Shutdown and Monitoring Zones for Concurrent Activities
Proposed Shutdown Zones (m)
Phase (Year)

Activity

Phase 1 (Year 1)

Vibratory extract 18-in
concrete piles and
vibratory install 56-in
steel sheet piles

LFcetaceans

HFcetaceans

All other
marine
mammals

Level B
monitoring
zones all
marine
mammals

70

18,480

Vibratory extract 18-in
concrete piles; vibratory
install 56-in steel sheet
piles; impact install 18-in
concrete piles

90

18,480

Vibratory extract 18-in
concrete piles and
vibratory install 56-in
steel sheet piles

70

18,480

Vibratory install 56-in
steel sheet piles and
impact install 18-in
concrete piles

80

15,850

Vibratory extract 18-in
concrete piles and
vibratory install 56-in
steel sheet piles

70

18,480

Vibratory install 56-in
steel sheet piles and
impact install 16-in
composite piles

80

15,850

Phase II (Year 2)

Phase III (Year 3)

Based on our evaluation of the applicant's proposed measures, as well as other
measures considered by NMFS, NMFS has preliminarily determined that the proposed
mitigation measures provide the means of effecting the least practicable impact on the
affected species or stocks and their habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) 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 while
conducting the activities. 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 (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 activity; or (4) biological or behavioral context of exposure (e.g., age,
calving or feeding areas);
●

Individual marine mammal responses (behavioral or physiological) to

acoustic stressors (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
●

Mitigation and monitoring effectiveness.

Visual Monitoring

Marine mammal monitoring during pile driving and removal must be conducted by
qualified, NMFS approved PSOs, in accordance with the following:
●

PSOs must be independent of the activity contractor (e.g., employed by a

subcontractor) and have no other assigned tasks during monitoring periods;
●

At least one PSO must have prior experience performing the duties of a PSO

during construction activity pursuant to a NMFS-issued incidental take authorization;
●

Other PSOs may substitute other relevant experience, education (i.e., a degree

in biological science or related field), or training for prior experience performing the duties of
a PSO during construction activity pursuant to a NMFS-issued incidental take authorization;
●

PSOs must be approved by NMFS prior to beginning any activity subject to

this proposed rulemaking; and
●

A lead observer or monitoring coordinator must be designated. The lead

observer must have prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued incidental take authorization.
PSOs must have the following additional qualifications:
●

Ability to conduct field observations and collect data according to assigned

protocols;
●

Experience or training in the field identification of marine mammals,

including the identification of behaviors;
●

Sufficient training, orientation, or experience with the construction operation

to provide for personal safety during observations;
●

Writing skills sufficient to prepare a report of observations including but not

limited to: (1) the number and species of marine mammals observed; (2) dates and times
when in-water construction activities were conducted; (3) dates, times, and reason for
implementation of mitigation (or why mitigation was not implemented when required); and
(4) marine mammal behavior; and
●

Ability to communicate orally, by radio or in person, with Project personnel

to provide real-time information on marine mammals observed in the area as necessary.
Given the configuration of the harassment zones, which vary depending on the pile
type/size and the pile driver type (tables 9 and 10), it is assumed that two PSO would be
sufficient to monitor the zones for impact drivers, and three to four PSOs would be sufficient
to monitor the zones for vibratory drivers given the proposed placement of the observers in
the vicinity of the Project Area. However, additional monitors may be added if warranted by
the level of marine mammal activity in the area. PSOs will be placed at the best vantage
point(s) practicable (figure 3) to monitor for marine mammals and implement
shutdown/delay procedures when applicable by calling for the shutdown by the pile driver
operator. PSOs would be deployed on the Green Mile Fishing Pier during vibratory driving
of piles when monitoring zones are exceptionally large.
Monitoring will be conducted 30 minutes before, during, and after all in water
construction activities. In addition, observers shall record all incidents of marine mammal
occurrence, regardless of distance from activity, and shall document any behavioral reactions
in concert with distance from piles being driven or removed. Pile driving activities include
the time to install or remove a single pile or series of piles, as long as the time elapsed
between uses of the pile driving equipment is no more than 30 minutes.

Figure 3. Proposed Protected Species Observer Locations at Naval Station Norfolk at
Norfolk, Virginia (Green Mile Fishing Pier location not shown)

Acoustic Monitoring
The Navy will implement in situ acoustic monitoring efforts to measure SPLs from
in-water construction activities for pile types and methods that have not been previously
collected at NAVSTA Norfolk (table 14). The Navy will collect and evaluate acoustic sound
recording levels during pile driving activities. The Navy would collect data on 10 percent of
the number of total piles driven for each pile type. Hydrophones would be placed at locations
33 ft from the noise source and, where the potential for Level A (PTS onset) harassment
exists, at a second representative monitoring location that is a distance of 20 times the depth
of water at the pile location, to the maximum extent practicable. For the pile driving events
acoustically measured, 100 percent of the data will be analyzed. Please see the Navy's
Acoustic Monitoring Plan and section 13.2 in the application for additional detail.
Table 14 – Number of Piles for Hydroacoustic Monitoring
Pile Type

Total Piles

Number Monitored

Method of Install of
Removal
Vibratory

18-in concrete
18-in concrete

Impact

56-in steel sheet

Vibratory

16-in composite

Vibratory

16-in composite

Impact

20

Environmental data shall be collected and will include, but will not be limited to, the
following: (1) wind speed and direction; (2) air temperature; (3) humidity; (4) surface water
temperature; (5) water depth; (6) wave height; (7) weather conditions; and (8) other factors
that could contribute to influencing underwater sound levels (e.g., aircrafts, boats, etc.).
Reporting

The Navy is required to submit an annual report on all activities and marine mammal
monitoring results to NMFS within 90 days following the end of each construction year.
Additionally, a draft comprehensive 5-year summary report must be submitted to NMFS
within 90 days of the end of the Project. The annual reports will include an overall
description of work completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report must include:
●

Dates and times (begin and end) of all marine mammal monitoring;

●

Construction activities occurring during each daily observation period,

including: (a) how many and what type of piles were driven or removed and the method (i.e.,
impact or vibratory); and (b) the total duration of time for each pile (vibratory driving) or
number of strikes for each pile (impact driving);
●

PSO locations during marine mammal monitoring; and

●

Environmental conditions during monitoring periods (at beginning and end of

PSO shift and whenever conditions change significantly), including Beaufort sea state and
any other relevant weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance.
Upon observation of a marine mammal the following information must be reported:
●

Name of PSO who sighted the animal(s) and PSO location and activity at the

time of the sighting;
●

Time of the sighting;

●

Identification of the animal(s) (e.g., genus/species, lowest possible taxonomic

level, or unidentified), PSO confidence in identification, and the composition of the group if
there is a mix of species;

●

Distance and bearing of each observed marine mammal relative to the pile

being driven or removed for each sighting;
●

Estimated number of animals (min/max/best estimate);

●

Estimated number of animals by cohort (e.g., adults, juveniles, neonates,

group composition, etc.);
●

Description of any marine mammal behavioral observations (e.g., observed

behaviors such as feeding or traveling), including an assessment of behavioral responses
thought to have resulted from the activity (e.g., no response or changes in behavioral state
such as ceasing feeding, changing direction, flushing, or breaching);
●

Number of marine mammals detected within the harassment zones, by

species; and
●

Detailed information about implementation of any mitigation (e.g., shutdowns

and delays), a description of specified actions that ensured, and resulting changes in behavior
of the animal(s), if any.
The acoustic monitoring report must contain the informational elements described in
the Acoustic Monitoring Plan and, at minimum, must include:
●

Hydrophone equipment and methods: (1) recording device, sampling rate,

distance (m) from the pile where recordings were made; and (2) the depth of water and
recording device(s);
●

Type and size of pile being driven, substrate type, method of driving during

recordings (e.g., hammer model and energy), and total pile driving duration;
●

Whether a sound attenuation device is used and, if so, a detailed description

of the device used and the duration of its use per pile;

●

For impact pile driving: (1) number of strikes and strike rate; (2) depth of

substrate to penetrate; (3) pulse duration and mean, median, and maximum sound levels (dB
re: one µPa): (4) root mean square sound pressure level (SPLrms); and (5) cumulative sound
exposure level (SELcum), peak sound pressure level (SPLpeak), and single-strike sound
exposure level (SELs-s); and
●

For vibratory driving/removal: (1) duration of driving per pile; and 2) mean,

median, and maximum sound levels (dB re: one µPa): SPLrms, SELcum (and timeframe over
which the sound is averaged).
If no comments are received from NMFS within 30 days, the draft reports will
constitute the final reports. If comments are received, a final report addressing NMFS'
comments must be submitted within 30 days after receipt of comments. All PSO datasheets
and/or raw sighting data must be submitted with the draft marine mammal report.
Reporting Injured or Dead Marine Mammals
In the unanticipated event that the specified activity clearly causes the take of a
marine mammal in a manner prohibited by the LOA (if issued) and the regulations (e.g., an
injury, serious injury, or mortality) the Navy shall report the incident to Office of Protected
Resources, NMFS, and the Greater Atlantic Region New England/Mid-Atlantic Stranding
Coordinator. The report must include the following information:
●

Description of the incident;

●

Environmental conditions (e.g., Beaufort sea state, visibility);

●

Description of all marine mammal observations in the 24 hours preceding the

incident;
●

Species identification or description of the animal(s) involved;

●

Fate of the animal(s); and

●

Photographs or video footage of the animal(s) (if equipment is available).

Activities would not resume until NMFS is able to review the circumstances of the
prohibited take. NMFS would work with the Navy to determine what is necessary to
minimize the likelihood of further prohibited take and ensure MMPA compliance. The Navy
would not be able to resume their activities until notified by NMFS.
In the event that the Navy discovers an injured or dead marine mammal, and the lead
PSO determines that the cause of the injury or death is unknown and the death is relatively
recent (e.g., in less than a moderate state of decomposition as described in the next
paragraph), the Navy would immediately report the incident to the Office of Protected
Resources, NMFS, and the Greater Atlantic Region New England/Mid-Atlantic Stranding
Coordinator. The report would include the same information identified in the paragraph
above. Activities would be able to continue while NMFS reviews the circumstances of the
incident. NMFS would work with the Navy to determine whether modifications in the
activities are appropriate.
In the event that the Navy discovers an injured or dead marine mammal and the lead
PSO determines that the injury or death is not associated with or related to the activities
authorized in the LOA (e.g., previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), the Navy would report the incident to the Office of
Protected Resources, NMFS, and the NMFS Greater Atlantic Region New England/MidAtlantic Stranding Coordinator, within 24 hours of the discovery. The Navy would provide
photographs, video footage (if available), or other documentation of the stranded animal
sighting to NMFS and the Marine Mammal Stranding Network.
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” through
harassment, NMFS considers other factors, such as the likely nature of any impacts or
responses (e.g., intensity, duration), the context of any impacts or responses (e.g., critical
reproductive time or location, foraging impacts affecting energetics), as well as effects on
habitat, and the likely effectiveness of the 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 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).
To avoid repetition, this introductory discussion of our analysis applies to all the
species listed in table 3, given that many of the anticipated effects of this Project on different
marine mammal stocks are expected to be relatively similar in nature. Where there are
meaningful differences between species or stocks, or groups of species, in anticipated
individual responses to activities, impact of expected take on the population due to
differences in population status, or impacts on habitat, they are described independently in
the analysis below.

Construction activities associated with the Project, as outlined previously, have the
potential to disturb or displace marine mammals. Specifically, the specified activities may
result in take, in the form of Level B harassment from underwater sounds generated by pile
driving and removal. Potential takes could occur if marine mammals are present in zones
ensonified above the thresholds for Level B harassment, identified above, while activities are
underway.
Level A harassment is unlikely considering the small Level A harassment zones
(tables 9 and 10) and corresponding shutdown zones (tables 12 and 13) where activities
would cease if animals were present in those zones. Also, pile driving and removal activities
are of relatively short duration and an animal would have to remain within the area estimated
to be ensonified above the Level A harassment threshold for multiple hours to incur PTS.
This is highly unlikely given marine mammal movement throughout the area, especially for
small, fast-moving species such as small cetaceans and pinnipeds. Therefore, NMFS is not
proposing to authorize take by Level A harassment during any portion of the Navy’s
activities.
The nature of activities included in the Navy's pile driving Project precludes the
likelihood of serious injury or mortality. For all species and stocks, take will occur within a
limited, confined area (i.e., immediately surrounding NAVSTA Norfolk in the Chesapeake
Bay area) of the stock's range. Level B harassment will be reduced to the level of least
practicable adverse impact through use of mitigation measures described herein.
Furthermore, the number of individuals expected to be taken is extremely small relative to
the stock abundance for all species.
Effects on individuals that are taken by Level B harassment, on the basis of reports in
the literature as well as monitoring from other similar activities, will likely be limited to
reactions such as increased swimming speeds, increased surfacing time, decreased foraging
(if such activity were occurring), or avoidance (e.g., Thorson and Reyff 2006; Hampton
Roads Connector Partners 2023; W.F. Magann Corporation 2023). Individual animals, even
if taken multiple times, will most likely move away from the sound source and be
temporarily displaced from the areas of pile driving, although even this reaction has been
observed primarily only in association with impact pile driving. The pile driving activities
analyzed here are similar to, or less impactful than, numerous other construction activities
conducted along both Atlantic and Pacific coasts, which have taken place with no known
long-term adverse consequences from behavioral harassment. Furthermore, many Projects
similar to this one are also believed to result in multiple takes of individual animals without
any documented long-term adverse effects. Level B harassment will be minimized through
use of mitigation measures described herein and, if take does occur the impacts would be
expected to be minimal, particularly as the Project is located on a busy waterfront with high
amounts of vessel traffic and other ambient noise.
A UME has been declared for humpback whales in the U.S. Atlantic. However, we
do not expect authorized takes to exacerbate or compound upon these ongoing UMEs. As
noted previously, no injury, serious injury, or mortality is expected or authorized, and the
impact of Level B harassment takes of humpback whale will be minimized through the
incorporation of the mitigation measures. The UME does not yet provide cause for concern
regarding population-level impacts. Despite the UME, the relevant population of humpback
whales (the West Indies breeding population, or DPS) remains healthy.
The Project is also not expected to have significant adverse effects on affected marine
mammals' habitats. The Project activities will not modify existing marine mammal habitat for
a significant amount of time. The activities may cause some fish to leave the area of
disturbance, thus temporarily impacting marine mammals' foraging opportunities in a limited
portion of the foraging range; however, because of the short duration of the activities and the
relatively small area of the habitat that may be affected (with no known particular importance
to marine mammals), the impacts to marine mammal habitat are not expected to cause
significant or long-term negative consequences.
In summary and as described above, the following factors primarily support our
preliminary determination that the impacts resulting from this activity are not expected to
adversely affect any of the species or stocks through effects on annual rates of recruitment or
survival:
●

No serious injury or mortality is anticipated or authorized;

●

The intensity of anticipated takes by Level B harassment is relatively low for

all stocks;
●

The specified activity and associated ensonified areas are very small relative

to the overall habitat ranges of all species and do not include habitat areas of special
significance, including any pinniped haulouts;
●

The lack of anticipated significant or long-term negative effects to marine

●

The presumed efficacy of the mitigation measures in reducing the effects of

habitat;

the taking incidental to the specified activity; and
●

Monitoring reports from similar work in the Chesapeake Bay have

documented little to no effect on individuals of the same species impacted by similar
activities.
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
proposed monitoring and mitigation measures, NMFS preliminarily finds that the total

marine mammal take from the proposed activity will have a negligible impact on all affected
marine mammal species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals 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 and so, in
practice, where estimated numbers are available, NMFS compares the maximum number of
individuals taken in any year 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 maximum annual number of individuals to be taken
is fewer 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.
The maximum annual take NMFS proposes to authorize for the four marine mammal
stocks is below one-third of the estimated stock abundance for all species except for the
western north Atlantic (WNA) southern coastal migratory stock and the WNA northern
coastal migratory stock of bottlenose dolphins (see table 11).
There are three bottlenose dolphin stocks that could occur in the Project Area.
Therefore, the largest estimated annual take by Level B harassment of 6,712 bottlenose
dolphin would likely be split among the northern migratory coastal stock, the southern
migratory coastal stock, and the northern North Carolina estuarine stock (NNCES). Based on
the stocks' respective occurrence in the area, NMFS estimates that there would be no more
than 200 takes from the NNCES stock during each phase of construction, representing 24
percent of that population, with the remaining takes split evenly between the northern and
southern coastal migratory stocks. Based on the consideration of various factors as described
below, we have preliminarily determined that the number of individuals taken will comprise
less than one-third of the best available population abundance estimate of either coastal
migratory stock. Detailed descriptions of the stocks' ranges have been provided in the
Description of Marine Mammals in the Area of Specified Activities section.
Both the WNA northern migratory stock and the WNA southern migratory stock
have expansive ranges and they are the only dolphin stocks thought to make broad scale,
seasonal migrations in coastal waters of the WNA. Given the large ranges associated with
these two stocks, it is unlikely that large segments of either stock would approach the Project
Area and enter into the Chesapeake Bay. The majority of both stocks are likely to be found
widely dispersed across their respective habitat ranges and unlikely to be concentrated in or
near the Chesapeake Bay.
Furthermore, the Chesapeake Bay and nearby offshore waters represent the
boundaries of the ranges of each of the two coastal stocks during migration. The WNA
northern migratory stock is found during warm water months from coastal Virginia,
including the Chesapeake Bay and Long Island, New York. The stock migrates south in the
late summer and fall. During cold water months, dolphins may be found in coastal waters
from Cape Lookout, North Carolina, to the North Carolina/Virginia border. During JanuaryMarch, the WNA southern migratory stock appears to move as far south as northern Florida.
From April-June, the stock moves back north to North Carolina. During the warm water
months of July-August, the stock is presumed to occupy the coastal waters north of Cape
Lookout, North Carolina, to Assateague, Virginia, including the Chesapeake Bay. There is
likely some overlap between the stocks during spring and fall migrations, but the extent of
overlap is unknown.

In summary and as described above, the following factors primarily support our
determination regarding the incidental take of small numbers of the affected stocks of a
species or stock:
●

The maximum annual take of marine mammal stocks proposed for

authorization comprises less than three percent of any stock abundance (with the exception of
the three bottlenose dolphin stocks);
●

Potential bottlenose dolphin takes in the Project Area are likely to be

allocated among three distinct stocks;
●

Bottlenose dolphin stocks in the Project Area have extensive ranges and it

would be unlikely to find a high percentage of the individuals of any one stock concentrated
in a relatively small area such as the Project Area or the Chesapeake Bay;
●

The Chesapeake Bay represents the migratory boundary for each of the

specified dolphin stocks and it would be unlikely to find a high percentage of any stock
concentrated at such boundaries; and
●

Many of the takes would likely be repeats of the same animals, including

from a resident population of the Chesapeake Bay.
Based on the analysis contained herein of the proposed activity (including the
proposed mitigation and monitoring measures) and the anticipated take of marine mammals,
NMFS preliminarily 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.
Endangered Species Act
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA; 16 U.S.C. 1531 et seq.)
requires that each Federal agency insure 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 issuance of IHAs, NMFS consults internally whenever we propose to
authorize take for endangered or threatened species.
No incidental take of ESA-listed species is proposed for authorization or expected to
result from this activity. Therefore, NMFS has determined that formal consultation under
section 7 of the ESA is not required for this action.
Request for Information
NMFS requests that interested persons submit comments, information, and
suggestions concerning the Navy's request and the proposed regulations (see ADDRESSES).
All comments will be reviewed and evaluated as we prepare a final rule and make final
determinations on whether to issue the requested authorization. This proposed rule and
supporting documents provide all environmental information relating to our proposed action
for public review.
Classification
Pursuant to the procedures established to implement Executive Order 12866, the
Office of Management and Budget has determined that this proposed rule is not significant.
Pursuant to section 605(b) of the Regulatory Flexibility Act (RFA), the Chief
Counsel for Regulation of the Department of Commerce has certified to the Chief Counsel
for Advocacy of the Small Business Administration that this proposed rule, if adopted, would
not have significant economic impact on a substantial number of small entities. The U.S.
Navy is the sole entity that would be subject to the requirements in these proposed
regulations, and the Navy is not a small governmental jurisdiction, small organization, or
small business, as defined by the RFA. Because of this certification, a regulatory flexibility
analysis in not required and none has been prepared.
This proposed rule does not contain a collection-of-information requirement subject
to the provisions of the Paperwork Reduction Act (PRA) because the applicant is a Federal
agency.

List of Subjects in 50 CFR Part 217
Acoustics, Administrative practice and procedure, Construction, Endangered and
threatened species, Marine mammals, Mitigation and Monitoring requirements, Reporting
requirements, Wildlife.

Dated: June 24, 2024.
Samuel D. Rauch, III,
Deputy Assistant Administrator for Regulatory Programs,
National Marine Fisheries Service.

For reasons set forth in the preamble, NOAA proposes to amend 50 CFR part 217 as
follows:
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 X to read as follows
Subpart X -- Taking and Importing Marine Mammals Incidental to Navy Construction
of the Q8 Bulkhead Repair and Replacement Project at Naval Station Norfolk at
Norfolk, Virginia
Sec.
217.230 Specified activity and geographical region.
217.231 Effective dates.
217.232 Permissible methods of taking.
217.233 Prohibitions.
217.234 Mitigation requirements.
217.235 Requirements for monitoring and reporting.
217.236 Letters of Authorization.
217.237 Renewals and modifications of Letters of Authorization.

§ 217.230 Specified activity and geographical region.
(a) Regulations in this subpart apply only to the U.S. Navy (Navy) and those persons
it authorizes or funds to conduct activities on its behalf for the taking of marine mammals
that occurs in the areas outlined in paragraph (b) of this section and that occurs incidental to

construction activities related to the repair and replacement of the Q8 bulkhead at Naval
Station Norfolk at Norfolk, Virginia.
(b) The taking of marine mammals by the Navy may be authorized in a Letter of
Authorization (LOA) only if it occurs at Naval Station Norfolk, Norfolk, Virginia.
§217.231 Effective Dates
Regulations under this subpart are effective from January 1, 2025, through December
31, 2029.
§217.232 Permissible methods of taking.
Under an LOA issued pursuant to §§ 216.106 and 217.236 of this chapter, the Holder
of the LOA (hereinafter “Navy”) may incidentally, but not intentionally, take marine
mammals within the area described in § 217.230(b) by harassment associated with
construction activities related to the repair and replacement of the Q8 bulkhead, provided the
activity is in compliance with all terms, conditions, and requirements of the regulations in
this subpart and the applicable LOA.
§217.233 Prohibitions
(a) Except for the takings contemplated in § 217.232 and authorized by a LOA issued
under §§ 216.106 and 217.236 of this chapter, it is unlawful for any person to do any of the
following in connection with the activities described in § 217.230:
(1) Violate, or fail to comply with, the terms, conditions, and requirements of this
subpart or a LOA issued under §§ 216.106 and 217.236 of this chapter;
(2) Take any marine mammal not specified in such LOA;
(3) Take any marine mammal specified in such LOA in any manner other than as
specified;

(4) Take a marine mammal specified in such LOA after NMFS determines such
taking results in more than a negligible impact on the species or stocks of such marine
mammal; or
(5) Take a marine mammal specified in such LOA after NMFS determined such
taking results in an unmitigable adverse impact on the species or stock of such marine
mammal for taking for subsistence uses.
§217.234 Mitigation requirements.
(a) When conducting the activities identified in § 217.230(a), the mitigation measures
contained in this subpart and any LOA issued under §§ 216.106 and 217.236 of this chapter
must be implemented by the Navy. These mitigation measures include:
(1) A copy of any issued LOA must be in the possession of the Navy, supervisory
construction personnel, lead protected species observers (PSOs), and any other relevant
designees of the Navy operating under the authority of the LOA at all times that activities
subject to the LOA are being conducted;
(2) The Navy must ensure that construction supervisors and crews, the monitoring
team, and relevant Navy staff are trained prior to the start of activities subject to any issued
LOA, so that responsibilities, communication procedures, monitoring protocols, and
operational procedures are clearly understood. New personnel joining during the Project must
be trained prior to commencing work;
(3) The Navy, construction supervisors and crews, and relevant Navy staff must avoid
direct physical interaction with marine mammals during construction activity. If a marine
mammal comes within 10 m of such activity, operations must cease and vessels must reduce
speed to the minimum level required to maintain steerage and safe working conditions, as
necessary to avoid direct physical interaction;

(4) The Navy must employ PSOs and establish monitoring locations as described in
the NMFS-approved Marine Mammal Monitoring Plan. The Navy must monitor the Project
Area to the maximum extent possible based on the required number of PSOs, required
monitoring locations, and environmental conditions;
(5) For all pile driving activities, the Navy shall implement shutdown zones with
radial distances as identified in a LOA issued under § 217.236. If a marine mammal is
observed entering or within the shutdown zone, such operations must be delayed or halted.
(6) Monitoring must take place from 30 minutes prior to initiation of a pile driving
activity (i.e., pre-start clearance monitoring) through 30 minutes post-completion of a pile
driving activity.
(7) Pre-start clearance monitoring must be conducted during periods of visibility
sufficient for the lead PSO to determine that the shutdown zones are clear of marine
mammals. Pile driving may commence following 30 minutes of observation when the
determination is made that the shutdown zones are clear of marine mammals.
(8) If a marine mammal is observed entering or within the shutdown zones, pile
driving activity must be delayed or halted.
(9) If pile driving is delayed or halted due to the presence of a marine mammal, the
activity may not commence or resume until either the animal has voluntarily exited and been
visually confirmed beyond the shutdown zone or 15 minutes have passed without redetection of the animal.
(10) Pile driving activity must be halted upon observation of either a species for
which incidental take is not authorized or a species for which incidental take has been
authorized but the authorized number of takes has been met, entering or within the
harassment zone.

(11) The Navy must use soft start techniques when impact pile driving. Soft start
requires contractors to provide an initial set of strikes at reduced energy, followed by a 30second waiting period, then two subsequent reduced-energy strike sets. A soft start must be
implemented at the start of each day's impact pile driving and at any time following cessation
of impact pile driving for a period of 30 minutes or longer.
§217.235 Requirements for monitoring and reporting.
(a) The Navy shall submit a Marine Mammal Monitoring Plan to NMFS for approval
in advance of construction. Marine mammal monitoring must be conducted in accordance
with the conditions in this section and the NMFS-approved Marine Mammal Monitoring
Plan.
(b) Monitoring must be conducted by qualified, NMFS-approved PSOs, in
accordance with the following conditions:
(1) PSOs must be independent of the activity contractor (e.g., employed by a
subcontractor) and have no other assigned tasks during monitoring periods;
(2) At least one PSO must have prior experience performing the duties of an observer
during construction activity pursuant to a NMFS-issued incidental take authorization;
(3) Other observers may substitute other relevant experience, education (i.e., degree
in biological science or related field), or training for prior experience performing the duties of
an observer during construction activity pursuant to a NMFS-issued incidental take
authorization;
(4) One observer must be designated as lead observer or monitoring coordinator. The
lead observer must have prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued incidental take authorization;
(5) Observers must be approved by NMFS prior to beginning any activity subject to
any issued LOA;
(6) For all pile driving activities, a minimum of two observers shall be stationed at
the best vantage points practicable. One of these observers must be positioned to monitor for
marine mammals and implement shutdown/delay procedures.
(7) The Navy shall monitor the harassment zones to the maximum extent practicable
and the entire shutdown zones. The Navy shall monitor at least a portion of the Level B
harassment zone on all pile driving days.
(8) The Navy shall conduct hydroacoustic data collection in accordance with an
Acoustic Monitoring Plan that must be approved by NMFS in advance of construction.
(9) The shutdown/monitoring zones may be modified with NMFS' approval
following NMFS' acceptance of an acoustic monitoring report.
(10) The Navy must submit a draft monitoring report to NMFS within 90 calendar
days of the completion of each construction year. A draft comprehensive five-year summary
report must also be submitted to NMFS within 90 days of the end of the Project. The reports
must detail the monitoring protocol and summarize the data recorded during monitoring.
Final annual reports and the final comprehensive report must be prepared and submitted
within 30 days following resolution of any NMFS comments on the draft report. If no
comments are received from NMFS within 30 days of receipt of the draft report, the report
must be considered final. If comments are received, a final report addressing NMFS
comments must be submitted within 30 days after receipt of comments. The reports must at
minimum contain the informational elements described below (as well as any additional
information described in the Marine Mammal Monitoring Plan), including:
(i) Dates and times (begin and end) of all marine mammal monitoring;
(ii) Construction activities occurring during each daily observation period, including
the number and type of piles that were driven or removed and by what method (i.e., impact or

vibratory), total duration of driving time for each pile (vibratory) and number of strikes for
each pile (impact);
(iii) PSO locations during marine mammal monitoring;
(iv) Environmental conditions during monitoring periods (at beginning and end of
PSO shift and whenever conditions change significantly), including Beaufort sea state and
any other relevant weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance;
(v) Upon observation of a marine mammal, the following information:
(A) Name of PSO who sighted the animal(s) and PSO location and activity at
time of sighting;
(B) Time of sighting;
(C) Identification of the animal(s) (e.g., genus/species, lowest possible
taxonomic level, or unidentified), PSO confidence in identification, and the
composition of the group if there is a mix of species;
(D) Distance and location of each observed marine mammal relative to the
pile being driven for each sighting;
(E) Estimated number of animals (min/max/best estimate);
(F) Estimated number of animals by cohort (adults, juveniles, neonates, group
composition, etc.);
(G) Animal's closest point of approach and estimated time spent within the
harassment zone;
(H) Description of any marine mammal behavioral observations (e.g.,
observed behaviors such as feeding or traveling), including an assessment of
behavioral responses thought to have resulted from the activity (e.g., no

response or changes in behavioral state such as ceasing feeding, changing
direction, flushing, or breaching);
(vii) Number of marine mammals detected within the harassment zones, by species;
and
(viii) Detailed information about implementation of any mitigation (e.g., shutdown
and delays), a description of specific actions that ensued, and resulting changes in behavior of
the animal(s), if any.
(11) The Holder must submit all PSO data electronically in a format that can be
queried such as a spreadsheet or database (i.e., digital images of data sheets are not
sufficient).
(12) The Navy must report hydroacoustic data collected as required by a LOA issued
under §§ 216.106 of this chapter and 217.236 and as discussed in the Navy's Acoustic
Monitoring Plan approved by NMFS.
(13) In the event that personnel involved in the construction activities discover an
injured or dead marine mammal, the Navy shall report the incident to the Office of Protected
Resources (OPR), NMFS, and to the Greater Atlantic Region New England/Mid-Atlantic
Regional Stranding Coordinator as soon as feasible. If the death or injury was clearly caused
by the specified activity, the Navy must immediately cease the specified activities until
NMFS 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 authorization.
The Navy must not resume their activities until notified by NMFS. The report must include
the following information:
(i) Time, date, and location (latitude/longitude) of the first discovery (and updated
location information if known and applicable);
(ii) Species identification (if known) or description of the animal(s) involved;
(iii) Condition of the animal(s) (including carcass condition if the animal is dead);
(iv) Observed behaviors of the animal(s), if alive;
(v) If available, photographs or video footage of the animal(s); and
(vi) General circumstances under which the animal was discovered.
§ 217.236 Letters of Authorization.
(a) To incidentally take marine mammals pursuant to these regulations, the Navy
must apply for and obtain an LOA.
(b) An LOA, unless suspended or revoked, may be effective for a period of time not
to exceed the expiration date of these regulations.
(c) If an LOA expires prior to the expiration date of these regulations, the Navy may
apply for and obtain a renewal of the LOA.
(d) In the event of projected changes to the activity or to mitigation and monitoring
measures required by an LOA, the Navy must apply for and obtain a modification of the
LOA as described in § 217.236.
(e) The LOA must set forth the following information:
(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.
(f) 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 these
regulations.
(g) Notice of issuance or denial of an LOA must be published in the Federal Register
within 30 days of a determination.
§ 217.237 Renewals and modifications of Letters of Authorization.
(a) An LOA issued under §§ 216.106 of this chapter and 217.236 for the activity
identified in § 217.230(a) may be renewed or modified upon request by the applicant,
provided that:
(1) The proposed specified activity and mitigation, monitoring, and reporting
measures, as well as the anticipated impacts, are the same as those described and analyzed for
these regulations; and
(2) NMFS determines that the mitigation, monitoring, and reporting measures
required by the previous LOA under these regulations were implemented.
(b) For LOA modification or renewal requests by the applicant that include changes
to the activity or the mitigation, monitoring, or reporting that do not change the findings
made for the regulations or result in no more than a minor change in the total estimated
number of takes (or distribution by species or years), NMFS may publish a notice of
proposed 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 §§ 216.106 of this chapter and 217.236 for the activity
identified in § 217.230(a) may be modified by NMFS under the following circumstances:
(1) NMFS may modify (including augment) the existing mitigation, monitoring, or
reporting measures (after consulting with Navy regarding the practicability of the
modifications) if doing so creates a reasonable likelihood of more effectively accomplishing
the goals of the mitigation and monitoring set forth in the preamble for these regulations;
(i) Possible sources of data that could contribute to the decision to modify the
mitigation, monitoring, or reporting measures in a LOA:
(A) Results from Navy's monitoring from previous years;
(B) Results from other marine mammal 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 these regulations or subsequent LOAs; and
(ii) If, through adaptive management, the modifications to the mitigation, monitoring,
or reporting measures are substantial, NMFS must publish a notice of proposed LOA in the
Federal Register and solicit public comment;
(2) If NMFS determines that an emergency exists that poses a significant risk to the
well-being of the species or stocks of marine mammals specified in a LOA issued pursuant to
§ 216.106 of this chapter and § 217.236, a LOA may be modified without prior notice or
opportunity for public comment. Notification would be published in the Federal Register
within 30 days of the action.
§§ 217.238 - 217.239 [Reserved]

[FR Doc. 2024-14162 Filed: 7/2/2024 8:45 am; Publication Date: 7/3/2024]