Notice2022-01474
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Replacement of Pier 3 at Naval Station Norfolk in Norfolk, Virginia
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
January 26, 2022
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from the United States Department of the Navy (Navy) for authorization to take marine mammals incidental to the replacement of Pier 3 at Naval Station Norfolk in Norfolk, Virginia. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue an incidental harassment authorization (IHA) to incidentally take marine mammals during the specified activities. NMFS is also requesting comments on a possible one-time, one-year renewal that could be issued under certain circumstances and if all requirements are met, as described in Request for Public Comments at the end of this notice. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorizations and agency responses will be summarized in the final notice of our decision.
Full Text
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<title>Federal Register, Volume 87 Issue 17 (Wednesday, January 26, 2022)</title>
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[Federal Register Volume 87, Number 17 (Wednesday, January 26, 2022)]
[Notices]
[Pages 3976-4001]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-01474]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XB562]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Replacement of Pier 3 at Naval
Station Norfolk in Norfolk, Virginia
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments on proposed authorization and possible renewal.
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SUMMARY: NMFS has received a request from the United States Department
of the Navy (Navy) for authorization to take marine mammals incidental
to the replacement of Pier 3 at Naval Station Norfolk in Norfolk,
Virginia. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is
requesting comments on its proposal to issue an incidental harassment
authorization (IHA) to incidentally take marine mammals during the
specified activities. NMFS is also requesting comments on a possible
one-time, one-year renewal that could be issued under certain
circumstances and if all requirements are met, as described in Request
for Public Comments at the end of this notice. NMFS will consider
public comments prior to making any final decision on the issuance of
the requested MMPA authorizations and agency responses will be
summarized in the final notice of our decision.
DATES: Comments and information must be received no later than February
25, 2022.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service and should be submitted via email to
<a href="/cdn-cgi/l/email-protection#8ec7dadea0cde1fcede1fcefe0cee0e1efefa0e9e1f8"><span class="__cf_email__" data-cfemail="6f263b3f412c001d0c001d0e012f01000e0e41080019">[email protected]</span></a>.
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments, including all attachments, must
not exceed a 25-megabyte file size. All comments received are a part of
the public record and will generally be posted online at
<a href="http://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a> without change. All personal identifying
[[Page 3977]]
information (e.g., name, address) voluntarily submitted by the
commenter may be publicly accessible. Do not submit confidential
business information or otherwise sensitive or protected information.
FOR FURTHER INFORMATION CONTACT: Kim Corcoran, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: <a href="https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a>. In case of problems accessing these
documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are issued or, if the taking is limited to harassment, a notice of a
proposed incidental take authorization may be 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.
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 an IHA)
with respect to potential impacts on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NOAA Administrative Order 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 IHA
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 the
IHA request.
Summary of Request
On July 15, 2021 NMFS received a request from the Navy for an IHA
to take marine mammals incidental to the reconstruction of Pier 3 at
Naval Station Norfolk in Norfolk, Virginia. The application was deemed
adequate and complete on October 27, 2021. Subsequently, the Navy
provided a revised and updated version of the application, which was
determined to be adequate and complete on January 10, 2022. The Navy's
request is for take of a small number of five species by Level B
harassment and Level A harassment. Neither the Navy nor NMFS expects
serious injury or mortality to result from this activity and,
therefore, an IHA is appropriate. NMFS previously issued IHAs to the
Navy for similar work (86 FR 48986; September 1, 2021; 85 FR 33139;
June 01, 2020; 83 FR 30406; June 28, 2018). This proposed IHA would
cover one year of a larger project for which the Navy plans to submit a
request for a Letter of Authorization (LOA) for additional work
occurring from April 1, 2023 through December 30, 2026. The larger 4-
year project involves the demolition and reconstruction of a submarine
pier at Naval Station Norfolk.
Description of Proposed Activity
Overview
The Navy is proposing the replacement of Pier 3 at Naval Station
(NAVSTA) Norfolk in Norfolk, VA. The existing Pier 3 would be
completely demolished and a new Pier 3 will be constructed immediately
north of the existing location (See Figure 1). Work at Pier 4, Pier 3T
and the bulkheads associated with Pier 3 and 3T (CEP-175, CEP-176, and
CEP-102) will also occur (See Figure 1). The proposed project includes
impact and vibratory pile driving and vibratory pile removal and
drilling. Drilling is considered a continuous noise source, similar to
vibratory pile driving. Sounds resulting from pile driving and removal
may result in the incidental take of marine mammals by Level A and
Level B harassment in the form of auditory injury or behavioral
harassment. The in-water construction period for the proposed action
will occur over 12 months.
Dates and Duration
The proposed IHA would be effective from April 1, 2022 to March 31,
2023. Approximately 280 days will be required for the project. The Navy
plans to conduct all work during daylight hours.
Specific Geographic Region
Pier 3 at NAVSTA Norfolk is located at the confluence of the
Elizabeth River, James River, Nansemond River, LaFeyette, Willoughby
Bay, and Chesapeake Bay (Figure 2).
Human generated 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, noise-producing vessel traffic that,
altogether, have an annual average of 1,788 vessel calls (Port of
Virginia, 2021). Other sources of human-generated underwater sound not
specific to naval installations include sounds from echo sounders on
commercial and recreational vessels, industrial ship noise, and noise
from recreational boat engines. Additionally, on average, maintenance
dredging of the navigation channel occurs every 2 years (USACE and Port
of Virginia, 2018).
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BILLING CODE 3510-22-C
Detailed Description of Specific Activity
The proposed project involves the replacement of Pier 3 at the
NAVSTA waterfront. The existing Pier 3 would be completely demolished
and a new Pier 3 would be constructed immediately north of the existing
location. Additional work associated with the replacement of Pier 3
includes the outfitting of Pier 4 for temporary submarine berthing,
demolition of Pier 3T, construction at the CEP-176 and the CEP-175
bulkheads, and beginning of construction of the CEP-102 bulkhead and
relieving platform. The project includes six phases that will be
completed under this proposed IHA and the future requested LOA. A
preliminary work schedule and activity details for the work under this
proposed IHA are provided in Table 1. In water construction activities
and specific project phases that would occur under this IHA are
described in more detail below:
Pile Removal--Piles are anticipated to be removed with a vibratory
hammer, however direct pull or clamshell removal may be used depending
on site conditions. Since vibratory removal is the loudest activity, to
be precautionary, we assume all piles will be removed with a vibratory
hammer. Pile removal methods are described as follows:
[[Page 3980]]
<bullet> Vibratory Extraction--This method uses a barge-mounted
crane with a vibratory driver to remove all pile types. The vibratory
driver is suspended from a crane by a cable and positioned on top of
the pile to loosen the pile from the sediment. Once the pile is
released from the sediments, the crane continues to raise the driver
and pull the pile from the sediment and place it on a barge;
<bullet> Clamshell--In cases where 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. The use and size of the clamshell bucket
would be minimized to reduce the potential for generating turbidity
during removal; and
<bullet> Direct Pull--Pile may also be removed by wrapping piles
with a cable or chain and pulling them directly from the sediment with
a crane. This method is based on site conditions.
Pile Installation--The proposed pile installation/removal would
occur using land-based or barge-mounted cranes and vary in method based
on pile type. Concrete piles would be installed using an impact hammer.
Steel piles and polymeric piles would be installed using an impact
hammer or vibratory hammer. Drilling may also occur for the
installation of concrete bearing piles at CEP-102, concrete fender
piles, and polymeric fender piles. No concurrent activity will occur.
Outfitting Pier 4--In order to support the temporary berthing of
submarines, Pier 4 fender support piles will be replaced with stronger,
more structurally sound fender piles. On the south side of Pier 4 (see
Figure 1), 36, 14-inch timber piles will be removed with a vibratory
hammer and 36, 24-inch precast square concrete piles will be installed
with an impact hammer with drilling used as necessary.
Demolition of Pier 3T--The existing Pier 3T will be completely
demolished and will not be replaced. Demolition of Pier 3T will include
the removal of 286, 18-inch square concrete piles and 87, 14-inch
timber piles using a vibratory hammer.
CEP-175 Bulkhead--Once Pier 3T is demolished, a new fender system
will be constructed at CEP-175 where Pier 3T previously abutted the
bulkhead (see Figure 1). To accomplish this, nine, 13-inch polymeric
fender piles would be installed to align with the existing fender
system. Piles will be installed with either impact or vibratory
hammers, with drilling used as necessary.
Pier 3 Construction--The new Pier 3 will be constructed immediately
north of and adjacent to the current Pier 3 (see Figure 1). The new
pier will consist of a cast in place concrete deck supported by 530,
24-inch square concrete bearing piles. A fender system will be
constructed on the north and south sides of the pier consisting of 392,
24-inch square concrete and 18, 18-inch steel pipe fender piles for
berthing submarines. The fender system piles would not be installed in
year one and therefore are not analyzed in this proposed IHA.
CEP-176 Bulkhead--The wharf upgrade will consist of a new steel
combi-wall bulkhead and relieving platform on the landside of the
bulkhead that serves as the bulkhead anchoring system. The bulkhead
will be constructed using 109, 42-inch steel pipe bearing piles and
221, 28-inch steel sheet piles. The steel pipe pile/steel sheet pile
combination will be driven waterside of the existing deteriorated
concrete bulkhead and will be installed with either an impact or
vibratory hammer. Once Pier 3T is demolished and the new CEP-176
bulkheads are completed, dredging would occur along the face of CEP-176
bulkhead to allow for safe berthing and maneuvering. As described
above, the project area is a noisy, industrial area. Noise created
during dredging operations may exceed harassment thresholds, but is
similar to noise produced through other common activities occurring at
the project location and is unlikely to be distinguishable from the
background noise created by ongoing industrial activity. Therefore, the
likelihood of harassing marine mammals is reduced and no incidental
takes are expected as a result of the dredging activity. Dredging and
disposal activities are not discussed further in this document.
CEP-102 Bulkhead--Repairs to the CEP-102 bulkhead will begin with
the demolition of a portion of the existing fender pile system prior to
new construction of Pier 3 and the CEP-176 bulkhead. Fender piles to be
removed include: 22, 18-inch square concrete fender piles, 9, 14-inch
timber fender piles, and 4, 13-inch polymeric piles. All piles will be
removed by use of a vibratory hammer. A steel combi-wall bulkhead and a
reinforced concrete relieving platform would then be constructed in two
phases, with a small, approximately 50-foot portion, constructed
concurrently with construction of the new Pier 3. Noise producing
sources will not be used simultaneously, however. The portion of the
CEP-102 combi-wall that will be constructed under this proposed IHA
consists of 4, 42-inch steel pipe bearing piles and 8, 28-inch steel
sheet piles that will be installed with either an impact or vibratory
hammer. Eleven, 24-inch precast concrete fender piles will also be
installed using an impact hammer. Drilling may be utilized as needed
prior to the use of the impact hammer.
Table 1 outlines a preliminary work schedule for the demolition and
reconstruction of Pier 3 at NAVSTA. Some project elements will use only
one method of pile installation (e.g., vibratory OR drilling/impact OR
impact only), but all methods have been analyzed. The method of
installation will be determined by the construction crew once
demolition and installation has begun. Therefore, the total take
estimate reflects the worst case scenario for the proposed project.
Table 1--Preliminary Estimated In-Water Construction Schedule for Year 1
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Daily
Amount and production Strikes/duration per Total
Location Activity schedule Type and size Method \1\ rate (piles/ pile production
day) days
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pier 4............. Demolition of 36 fender piles 14-inch timber.... Vibratory Hammer.. 4 60 minutes.............. 9
Existing Fender June 2022-
Piles. September 2022.
------------------------------------------------------------------------------------------------------------------------------------
Installation of 36 fender piles 24-inch precast Drilling with 6 6 hours................. 6
Fender Piles. June 2022- concrete square. Impact Hammer OR.
September 2022.
------------------------------------------------------------------------
Impact Hammer..... 12 450 strikes............. 3
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[[Page 3981]]
Pier 3T............ Demolition of 286 bearing piles 18-inch precast Vibratory Hammer.. 4 60 minutes.............. 72
Existing Pier 3T. August 2022- concrete square.
November 2022.
----------------------------------------------------------------------------------------------------------------
87 fender piles 14-inch timber.... Vibratory Hammer.. 4 60 minutes.............. 22
August 2022-
November 2022.
--------------------------------------------------------------------------------------------------------------------------------------------------------
CEP-175............ Repair Fender 9 fender piles 13-inch polymeric. Drilling with 7 60 minutes.............. 2
System. October 2022- Impact Hammer OR.
November 2022.
------------------------------------------------------------------------
Impact Hammer OR.. 7 450 strikes............. 2
------------------------------------------------------------------------
Vibratory Hammer.. 7 30 minutes.............. 2
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CEP-102............ Demolish Partial 22 fender piles 18-inch concrete Vibratory Hammer.. 4 60 minutes.............. 6
Existing Fender October 2022- square.
System. November 2022.
----------------------------------------------------------------------------------------------------------------
9 fender piles 14-inch timber.... Vibratory Hammer.. 4 60 minutes.............. 3
October 2022-
November 2022.
----------------------------------------------------------------------------------------------------------------
4 fender piles.... 13-inch polymeric. Vibratory Hammer.. 4 60 minutes.............. 1
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Pier 3............. Begin Construction 300 bearing piles 24-inch precast Impact Hammer..... 2 3,200 strikes........... 150
of New Pier 3. October 2022- concrete square.
March 2023.
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CEP-176............ Begin Construction 109 bearing piles 42-inch steel pipe Impact Hammer OR.. 2 1,800 strikes........... 55
of New Bulkhead. December 2022-30
March 2023.
------------------------------------------------------------------------
Vibratory Hammer.. 2 240 minutes............. 55
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221 sheet piles 28-inch steel Impact Hammer OR.. 4 270 strikes............. 56
December 2022-30 sheet.
March 2023.
------------------------------------------------------------------------
Vibratory Hammer.. 4 60 minutes.............. 56
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CEP-102............ Construction of a 4 bearing piles 42-inch steep pipe Impact Hammer OR.. 2 2,000 strikes........... 2
Portion of the December 2022-30
New Bulkhead. March 2023.
------------------------------------------------------------------------
Vibratory Hammer.. 2 240 minutes............. 2
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8 bulkhead sheet 28-inch steel Impact Hammer OR.. 4 270 strikes............. 2
piles December sheet.
2022-30 March
2023.
------------------------------------------------------------------------
Vibratory Hammer.. 4 60 minutes.............. 2
----------------------------------------------------------------------------------------------------------------
11 bearing piles 24-inch precast Pre-drilling with 2 6 hours................. 6
December 2022-30 concrete square. Impact Hammer OR.
March 2023.
------------------------------------------------------------------------
Impact Hammer..... 2 2,700 strikes........... 6
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Total piles installed, extracted, or 1,142.............
drilled.
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Total days pile .................. .................. .................. .................. ............ ........................ \2\ \3\ \4\
driving/extraction/ 280
drilling.
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\1\ Only one method of installation is likely; however, because the exact means of installation are up to the selected construction contractor, all
possibilities have been analyzed.
\2\ Total number of days takes into account the most days possible for each pile type with multiple potential installation methods (i.e., the worst case
scenario).
\3\ The preliminary schedule has work at Pier 4, demolition of Pier 3T, start of construction at Pier 3, and work at CEP-175 potentially occurring in
the same timeframe, thus multiple pile types could be driven in the same day and the total days of pile driving/extraction/drilling reflects this
assumption. Thus, the maximum number of days of work from these activities is associated with beginning the construction of Pier 3 (150 days). Adding
remaining work, minus those activities that would occur during the same time frame (Pier 4, demo Pier 3T, and CEP-175), equals 280 days.
\4\ Multiple types of equipment may be used on the same day; however, use of multiple noise sources (hammers or drills) would not occur at the same
time. There will be no simultaneous activities associated with this project.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
[[Page 3982]]
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the Navy's application summarize available
information regarding status and trends, distribution and habitat
preferences, and behavior and life history, of the potentially affected
species. Additional information regarding population trends and threats
may be found in NMFS's Stock Assessment Reports (SARs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 2 lists all species or stocks for which take is expected and
proposed to be authorized for this action, 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. For taxonomy, we follow Committee on
Taxonomy (2021). 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's SARs). While no
mortality is anticipated or authorized here, PBR and annual serious
injury and mortality from anthropogenic sources are included here as
gross indicators of the status of the species and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Atlantic and Gulf of Mexico SARs (e.g., Hayes et al.,
2021). All values presented in Table 2 are the most recent available at
the time of publication and are available in the 2021 draft SARs (Hayes
et al., 2021).
Table 2--Marine Mammal Species Likely To Occur Near the Project Area
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ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Eschrichtiidae:
Humpback whale.................. Megaptera novaeangliae. Gulf of Maine.......... -,-;Y 1,396 (0; 1,380; 2016) 22 12.15
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Bottlenose dolphin.............. Tursiops truncatus..... Western North Atlantic -,-; Y 6,636 (0.41; 4,759; 48 12.2-21.5
(WNA) Coastal, 2016).
Northern Migratory.
Bottlenose dolphin.............. Tursiops truncatus..... WNA Coastal, Southern -,-; Y 3,751 (0.06; 2,353; 24 0-18.3
Migratory. 2016).
Bottlenose dolphin.............. Tursiops truncatus..... Northern North Carolina -,-; Y 823 (0.06; 782; 2017). 7.8 7.2-30
Estuarine.
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... Gulf of Maine/Bay of -,-; N 95,543 (0.31; 74,034; 851 217
Fundy. 2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Superfamily Pinnipedia
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Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... WNA.................... -; N 61,336 (0.08; 57,637; 1729 339
2018).
Gray seal \4\................... Halichoerus grypus..... WNA.................... -; N 27,300 (0.22; 23,785; 1,389 4,453
2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (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.
\2\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments/">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments/</a> assessments/. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable [explain if this is
the case].
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury (M/SI) from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ This stock abundance estimate for only the U.S. portion of this stock. The actual stock abundance, including the Canadian portion of the population,
is estimated to be approximately 451,431 animals. The PBR value listed here is only for the U.S. portion of the stock, while M/SI reflects both the
Canadian and U.S. portions.
As indicated above, all five species (with seven managed stocks) in
Table 2 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur, and we have proposed
authorizing it. While North Atlantic right whales (Eubalaena
glacialis), minke whales (Balaenoptera acutorostrata acutorostrata),
and fin whales (Balaenoptera physalus) have been documented in the
area, the temporal and/or spatial occurrence of these whales is far
outside the proposed area for this project and take is not expected to
occur. Therefore, they are not discussed further beyond the explanation
provided below.
Based on sighting data and passive acoustic studies, the North
Atlantic right whale could occur off the coast of Virginia year-round
(Department of Navy (DoN) 2009; Salisbury et al., 2006). They have also
been reported seasonally off Virginia during migrations in the spring,
fall, and winter (Cetacean and Turtle Assessment Program (CeTAP) 1981,
1982; Niemeyer et al., 2008; Kahn et al., 2009; McLellan 2011b, 2013;
Mallette et al., 2016a, 2016b, 2017, 2018a; Palka et al., 2017; Cotter
2019). Right whales are known to frequent the coastal waters of the
mouth of the Chesapeake Bay (Knowlton et al., 2002) and the area is a
seasonal management area (November 1-April 30) mandating reduced ship
speeds out to approximately 20 nautical miles (37 kilometers [km]);
however, the project
[[Page 3983]]
area is further inside the Bay and away from this area.
North Atlantic right whales have stranded in Virginia, one each in
2001, 2002, 2004, 2005; three during winter (February and March) and
one in summer (September) Costidis et al., 2017, 2019). In January
2018, a dead, entangled North Atlantic right whale was observed
floating over 60 miles (96.6 km) offshore of Virginia Beach (Costidis
et al., 2019). All North Atlantic right whale strandings in Virginia
waters have occurred on ocean-facing beaches along Virginia Beach and
the barrier islands seaward of the lower Delmarva Peninsula (Costidis
et al., 2017). Right whales are not expected to occur in the project
area, and NMFS is not proposing to authorize take of this species.
Fin whales have been sighted off Virginia (CeTAP 1981, 1982;
Swingle et al., 1993, DoN 2009; Hyrenback et al., 2012; Barco 2013;
Mallette et al., 2016a, b; Aschettino et al., 2018; Engelhaupt et al.,
2017, 2018; Cotter 2019), and in the Chesapeake Bay (Bailey 1948; CeTAP
1981, 1982; Morgan et al., 2002; Barco 2013; Aschettino et al., 2018);
however, they are not likely to occur in the project area. Sightings
have been documented around the Chesapeake Bay Bridge Tunnel (CBBT)
during the winter months (CeTAP 1981, 1982; Barco 2013; Aschettino et
al., 2018).
Eleven fin whale strandings have occurred off Virginia from 1988 to
2016 mostly during the winter months of February and March, followed by
a few in the spring and summer months (Costidis et al., 2017). Six of
the strandings occurred in the Chesapeake Bay (three on eastern shore;
three on western shore) with the remaining five occurring on the
Atlantic coast (Costidis et al., 2017. Documented strandings near the
project area have occurred: February 2012, a dead fin whale washed
ashore on Oceanview Beach in Norfolk (Swingle et al., 2013); December
2017, a live fin whale stranded on a shoal in Newport News and died at
the site (Swingle et al., 2018); February 2014, a dead fin whale
stranded on a sand bar in Pocomoke Sound near Great Fox Island,
Accomack (Swingle et al., 2015); and, March 2007, a dead fin whale near
Craney Island, in the Elizabeth River, in Norfolk (Barco 2013). Only
stranded fin whales have been documented in the project area; no free-
swimming fin whales have been observed. Fin whales are not expected to
occur in the project area, and NMFS is not proposing to authorize take
of this species.
Minke whales have been sighted off Virginia (CeTAP 1981, 1982;
Hyrenbach et al., 2012; Barco 2013; Mallette et al., 2016a, b; McLellan
2017; Engelhaupt et al., 2017, 2018; Cotter 2019), near the CBBT
(Aschettino et al., 2018), but sightings in the project area are from
strandings (Jensen and Silber 2004; Barco 2013; DoN 2009). In August
1994, a ship strike incident involved a minke whale in Hampton Roads
(Jensen and Silber 2004; Barco 2013). It was reported that the animal
was struck offshore and was carried inshore on the bow of a ship (DoN
2009). Twelve strandings of minke whales have occurred in Virginia
waters from 1988 to 2016 (Costidis et al., 2017). There have been six
minke whale stranding from 2017 through 2020 in Virginia waters. Minke
whales are not expected to occur in the project area, and NMFS is not
proposing to authorize take of this species.
Humpback Whales
Humpback whales are found worldwide in all oceans. In winter,
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.
Based on photo-identification, only 39 percent of individual
humpback whales observed along the mid- and south Atlantic U.S. coast
are from the Gulf of Maine stock (Barco et al., 2002). Therefore, the
SAR abundance estimate is an underrepresentation of the relevant
population, i.e., the West Indies breeding population.
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 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% CI
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).
Although humpback whales are migratory between feeding areas and
calving areas, individual variability in the timing of migrations may
result in the presence of individuals in high-latitude areas throughout
the year (Straley, 1990). Records of humpback whales off the U.S. mid-
Atlantic coast (New Jersey to North Carolina) from January through
March suggest these waters may represent a supplemental winter feeding
ground used by juvenile and mature humpback whales of U.S. and Canadian
North Atlantic stocks (LaBrecque et al., 2015).
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. Most recently, the Hampton Roads Bridge-Tunnel Expansion Project
(HRBT), which spanned from September 2020 through July 10, 2021 did not
observe any humpback whales near the project site between Norfolk and
Hampton, VA over
[[Page 3984]]
197 days of observations (Hampton Roads Connector Partners (HRCP),
Unpublished).
Bottlenose Dolphin
Along the U.S. East Coast and northern Gulf of Mexico, the
bottlenose dolphin stock structure is well studied. There are currently
53 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).
There are two morphologically and genetically distinct bottlenose
dolphin morphotypes (distinguished by physical differences) described
as coastal and offshore forms (Duffield et al., 1983; Duffield, 1986).
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 morphotype 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:
Western North Atlantic Northern Migratory Coastal stock and 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 to 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, 2018a). 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, 2018a). 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, 2018a).
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).
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 fall (October to December) and 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. In the recent
HRBT project, zero harbor porpoises were observed near the project area
(HRCP, Unpublished).
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., 2017; Kenney R.D. 2019; Waring et al., 2016).
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 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, the HRBT project
reported seeing zero seals in or around the project area (HRCP,
Unpublished).
Gray Seal
The Western North Atlantic stock of gray seal occurs in the project
area. The
[[Page 3985]]
western North Atlantic stock is centered in Canadian waters, including
the Gulf of St. Lawrence and the Atlantic coasts of Nova Scotia,
Newfoundland, and Labrador, Canada, and the northeast U.S. continental
shelf (Hayes et al., 2017). Gray seals range south into the
northeastern United States, with strandings and sightings as far south
as North Carolina (Hammill et al., 1998; Waring et al., 2004). Gray
seal distribution along the U.S. Atlantic coast has shifted in recent
years, with an increased number of seals reported in southern New
England (DiGiovanni et al., 2011; Kenney R.D., 2019; Waring et al.,
2016). Recent sightings included a gray seal in the lower Chesapeake
Bay during the winter of 2014 to 2015 (Rees et al., 2016). Along the
coast of the United States, gray seals are known to pup at three or
more colonies in Massachusetts and Maine.
Gray seals are uncommon in Virginia and in the Chesapeake Bay. Only
15 gray seal strandings were documented in Virginia from 1988 through
2013 (Barco and Swingle, 2014). They are rarely found resting on the
rocks around the portal islands of the CBBT from December through April
alongside harbor seals. Seal observation surveys conducted at the CBBT
recorded one gray seal in each of the 2014/2015 and 2015/2016 seasons
while no gray seals were reported during the 2016/2017 and 2017/2018
seasons (Rees et al., 2016, Jones et al., 2018). Sightings have been
reported off Virginia and near the project area during the winter and
spring (Barco 2013; Rees et al., 2016; Jones et al., 2018; Ampela et
al., 2019). However, the HRBT monitoring report indicated that zero
gray seals were observed during the course of their project (HRCP,
Unpublished).
Unusual Mortality Events
An unusual mortality event (UME) is defined under Section 410(6) of
the MMPA as a stranding that is unexpected; involves a significant die-
off of any marine mammal population; and demands immediate response.
Currently, ongoing UME investigations are underway for pinnipeds along
the Northeast Atlantic coast. There is an active UME for humpback
whales along the Atlantic coast.
Northeast Pinniped UME
Since July 2018, elevated numbers of harbor seal and gray seal
mortalities have occurred across Maine, New Hampshire and
Massachusetts. This event has been declared an UME. Additionally, seals
showing clinical signs have been stranding as far south as Virginia,
although not in elevated numbers; therefore, the UME investigation now
encompasses all seal strandings from Maine to Virginia. Lastly, while
take is not proposed for these species in this proposed IHA, ice seals
(harp and hooded seals) have also started stranding with clinical
signs, again not in elevated numbers, and those two seal species have
also been added to the UME investigation. Additional information is
available at <a href="https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along">https://www.fisheries.noaa.gov/new-england-mid-atlantic/marine-life-distress/2018-2020-pinniped-unusual-mortality-event-along</a>.
Atlantic Humpback Whale UME
Since January 2016, elevated humpback whale mortalities have
occurred along the Atlantic coast from Maine through Florida. This
event has been declared an UME since 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. Additional information is available at <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2021-humpback-whale-unusual-mortality-event-along-atlantic-coast">https://www.fisheries.noaa.gov/national/marine-life-distress/2016-2021-humpback-whale-unusual-mortality-event-along-atlantic-coast</a>.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Current data indicate that not all marine
mammal species have equal hearing capabilities (e.g., Richardson et
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect
this, Southall et al., (2007) recommended that marine mammals be
divided into functional hearing groups based on directly measured or
estimated hearing ranges on the basis of available behavioral response
data, audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. Note that no direct measurements
of hearing ability have been successfully completed for mysticetes
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
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 3.
Table 3--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans (dolphins, 150 Hz to 160 kHz.
toothed whales, beaked whales,
bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true 50 Hz to 86 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 39 kHz.
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
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
[[Page 3986]]
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Five marine mammal species (three cetacean and two pinniped, both
phocid, species) have the reasonable potential to co-occur with the
proposed survey activities. Please refer to Table 2. Of the cetacean
species that may be present, one is classified as a low-frequency
cetacean (i.e., humpback whale), one is classified as a mid-frequency
cetacean (i.e., bottlenose dolphin), and one is classified as a high-
frequency cetacean (i.e., harbor porpoise).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The Estimated Take 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 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 how those
impacts on individuals are likely to impact marine mammal species or
stocks.
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 removal, impact and vibratory pile driving, and
drilling. The sounds produced by these activities fall into one of two
general sound types: Impulsive and non-impulsive. Impulsive sounds
(e.g., explosions, gunshots, sonic booms, impact pile driving) are
typically transient, brief (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 2018a). 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 2018a). 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). As mentioned previously, drilling
is considered a continuous source, similar to vibratory pile driving.
The drilling may be used before driving piles in order to facilitate
pile driving and hence the applicant calls this activity ``pre-
drilling'' in their application. For the proposed project, the drilling
apparatus utilized would vary depending on the different applications
during in-water construction activities. Drilling would be used as
necessary to remove sand with shell fragments or any obstructions in
order to accelerate pile driving.
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. Acoustic
stressors include effects of heavy equipment operation during pile
driving, removal and drilling.
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving or drilling 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). In general, exposure to
pile driving or drilling 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 or drilling
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 the 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
[[Page 3987]]
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 decibels (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
non-impulsive), 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, as with the
exception of a single study unintentionally inducing PTS in a harbor
seal (Kastak et al., 2008), 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 6 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
(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 drilling, 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 Harassment--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).
Disturbance may result in changing durations of surfacing and
dives, number of blows per surfacing, or moving direction and/or speed;
reduced/increased vocal activities; changing/cessation of certain
behavioral activities (such as socializing or feeding); visible startle
response or aggressive behavior (such as tail/fluke slapping or jaw
clapping); 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 factors
(e.g., Richardson et al., 1995; Wartzok et al., 2003; Southall et al.,
2007; Weilgart 2007; Archer et al., 2010). Behavioral reactions can
vary not only among individuals but also within an individual,
depending on previous experience with a sound source, context, and
numerous other factors (Ellison et al., 2012), and can vary depending
on characteristics associated with the sound source (e.g., whether it
[[Page 3988]]
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. Please see Appendices B-C of Southall et
al., (2007) for a review of studies involving marine mammal behavioral
responses to sound.
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.
Stress responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle 1950; Moberg
2000). In many cases, an animal's first and sometimes most economical
(in terms of energetic costs) response is behavioral avoidance of the
potential stressor. Autonomic nervous system responses to stress
typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker 2000; Romano
et al., 2002b) and, more rarely, studied in wild populations (e.g.,
Romano et al., 2002a). For example, Rolland et al., (2012) found that
noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC, 2003), however
distress is an unlikely result of this project based on observations of
marine mammals during previous, similar projects in the area.
Masking--Sound can disrupt behavior through masking, or interfering
with, an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al., 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and at similar or higher intensity, and may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar,
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions. Masking of natural sounds can result when human activities
produce high levels of background sound at frequencies important to
marine mammals. Conversely, if the background level of underwater sound
is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked.
Airborne Acoustic Effects--Although pinnipeds are known to haul-out
regularly on man-made objects, such as the nearby Chesapeake Bay Bridge
Tunnel, 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 (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 estimation 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 and drilling, no net habitat
loss is expected as the new Pier 3 will be immediately north of the
existing Pier 3 and once complete, the current Pier 3 will be
demolished. Construction activities are of short duration and would
likely have
[[Page 3989]]
temporary impacts on marine mammal habitat through increases in
underwater sounds. Increased noise levels may affect acoustic habitat
(see masking discussion above) 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 long-term
effects to the individuals or populations.
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 about 25-ft (7.6 meter) 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 Pier 3. The total seafloor area affected by pile
installation and removal is a very small area 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
demolition and reconstruction of Pier 3 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 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, fishes 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 depends 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, barotrauma (pressure-related
injuries), 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 at the
project areas 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
This section provides an estimate of the number of incidental takes
proposed for authorization through this IHA, which will inform both
NMFS' consideration of ``small numbers'' and the negligible impact
determination.
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);
[[Page 3990]]
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).
Authorized takes would primarily be by Level B harassment, as noise
generated from in-water pile driving (vibratory and impact) and
drilling has the potential to result in disruption of behavioral
patterns for individual marine mammals. There is also some potential
for auditory injury (Level A harassment) to result, primarily for high-
and low-frequency species and phocids because predicted auditory injury
zones are larger than for mid-frequency species. However, auditory
injury is unlikely to occur for mid-frequency species due to the
proposed shutdown zones (see Proposed Mitigation section).
Additionally, the proposed mitigation and monitoring measures are
expected to minimize the severity of the taking to the extent
practicable.
As described previously, no mortality is anticipated or proposed to
be authorized for this activity. Below we describe how the take is
estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals will be behaviorally harassed or incur some
degree of permanent hearing impairment; (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)
and the number of days of activities. We note that while these basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Below, we describe the
factors considered here in more detail and present the proposed take
estimate.
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 for non-explosive sources--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 (e.g., frequency, predictability,
duty cycle), the environment (e.g., bathymetry), and the receiving
animals (hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007,
Ellison et al., 2012). Based on what the available science indicates
and the practical need to use a threshold based on a factor that is
both predictable and measurable for most activities, NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. NMFS predicts that marine mammals are
likely to be behaviorally harassed in a manner we consider Level B
harassment when exposed to underwater anthropogenic noise above
received levels of 120 dB re 1 microPascal, root mean square ([mu]Pa
(rms)) for continuous (e.g., vibratory pile-driving, drilling) and
above 160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g.,
impact pile driving) or intermittent (e.g., scientific sonar) sources.
The Navy's construction includes the use of continuous (vibratory
pile driving, drilling) and impulsive (impact pile driving) sources,
and therefore the 120 and 160 dB re 1 [mu]Pa (rms) are applicable.
Level A harassment for non-explosive sources--NMFS' Technical
Guidance for Assessing the Effects of Anthropogenic Sound on Marine
Mammal Hearing (Version 2.0) (Technical Guidance, 2018) identifies dual
criteria to assess auditory injury (Level A harassment) to five
different marine mammal groups (based on hearing sensitivity) as a
result of exposure to noise from two different types of sources
(impulsive or non-impulsive). As previously noted, the Navy's proposed
activity include the use of impulsive (impact pile driving) and non-
impulsive (vibratory pile driving/removal, drilling) sources.
These thresholds are provided in the table 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
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
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.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. 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 being 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.
[[Page 3991]]
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
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, NMFS used acoustic monitoring data from other
locations to develop proxy source levels for the various pile types,
sizes and methods (Table 5). Generally we choose source levels from
similar pile types from locations (e.g., geology, bathymetry) similar
to the project. At this time, NMFS is not aware of reliable source
levels available for polymeric piles using vibratory pile installation,
therefore source levels for timber pile driving were used as a proxy.
Similarly, the following proxies were used as source levels for piles
where no data was available: Source levels for the 66-inch steel pile
was used as a proxy for 42-inch steel pipe piles (vibratory); the 30-
inch steel pile was used as a proxy for the 28-inch sheet piles
(impact); and 18-inch octagonal pile was used as a proxy for 18-inch
concrete piles (impact). Additionally, data on vibratory extraction of
concrete piles are not available, therefore the Navy followed previous
guidance suggesting that timber piles be used as a proxy for sound
source levels (see 84 FR 28474; June 19, 2019).
Very little information is available regarding source levels for
in-water drilling activities associated with nearshore pile
installation. Measurements made during a pile drilling project in 1-5 m
(3-16 ft) depths at Santa Rosa Island, CA, by Dazey et al., (2012)
appear to provide the best available proxy source levels for the
proposed activities. Dazey et al. (2012) reported average rms source
levels ranging from 151 to 157 dB re 1[micro]Pa, normalized to a
distance of 1 m (3 ft) from the pile, during activities that included
casing removal and installation as well as drilling, with an average of
154 dB re 1[micro]Pa during 62 days that spanned all related drilling
activities during a single season. 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, vibratory pile driving, and drilling).
Table 5--Project Sound Source Levels Normalized to 10 Meters
--------------------------------------------------------------------------------------------------------------------------------------------------------
Peak SPL (re 1 RMS SPL (re 1 SEL (re 1 [mu]Pa
Pile type Pile size (inch) Method [mu]Pa (rms)) [mu]Pa (rms)) (rms)) Source
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steel Pipe Pile............ 42.................... Impact................ 213 190 177 Navy 2015.
Vibratory............. ................ 168 168 Sitka 2017.
168
Steel Sheet................ 28.................... Impact................ 211 196 181 NAVFAC SW 2020.
Vibratory............. ................ 167 167 Navy 2015.
Concrete Pile.............. 24.................... Impact................ 189 176 163 Illingworth and
Vibratory............. 185 162 157 Rodkin 2017.
Caltrans 2020.
Concrete Pile.............. 18.................... Impact................ 185 166 154 Caltrans 2020.
Vibratory............. 185 162 157 Caltrans 2020.
Polymeric Pile............. 13.................... Impact................ 177 153 ................ Denes et al., 2016.
Vibratory............. 185 162 157 Caltrans 2020.
Timber Pile................ 14.................... Vibratory............. 185 162 157 Caltrans 2020.
NA......................... ``Multiple pile Drilling.............. ................ \2\ 154 154 Dazey et al., 2012.
sizes'' \1\ \2\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Pile sizes being installed using the drilling method might include 24-inch precast concrete square, 13-inch polymeric and 24-inch precast concrete
square.
\2\ Source levels were normalized to a distance of 1 m (3 ft) from the pile during activities that included casing removal and installation as well as
drilling, with an average of 154 dB re 1[mu]Pa during the course of the project.
When the NMFS Technical Guidance (2016) was published, in
recognition of the fact that ensonified area/volume could be more
technically challenging to predict because of the duration component in
the new thresholds, we developed a User Spreadsheet that includes tools
to help predict a simple isopleth that can be used in conjunction with
marine mammal density or occurrence to help predict takes. We note that
because of some of the assumptions included in the methods used for
these tools, we anticipate that isopleths produced are typically going
to be overestimates of some degree, which may result in some degree of
overestimate of Level A harassment take. However, these tools offer the
best way to predict appropriate isopleths when more sophisticated 3D
modeling methods are not available, and NMFS continues to develop ways
to quantitatively refine these tools, and will qualitatively address
the output where appropriate. For stationary sources in-water pile
driving/removal and drilling activities from the Navy's proposed
project, NMFS User Spreadsheet predicts the distance at which, if a
marine mammal remained at that distance the whole duration of the
activity, it would incur PTS. Inputs used in the User Spreadsheet are
reported in Table 1 and sources levels used in the User Spread are
reported in Table 5, and the resulting isopleths are reported in Table
6 (Impact) and Table 7 (Vibratory and Drilling) below.
Table 6--Level A and Level B Harassment Isopleths for Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A--Radius to isopleth (m) Level B--Radius to isopleth
----------------------------------------------------------- (m)
-------------------------------
Pile driving site Source Area within
LF cetaceans MF cetaceans HF cetaceans Phocids Distance to Level B
Level B threshold
threshold (m) (km\2\) \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pier 4............................ 24'' Concrete Fender..... 143 5 170 76 117 <0.1
CEP-175........................... 13'' Polymeric........... 22 1 26 12 3 <0.1
Pier 3............................ 24'' Concrete Bearing.... 160 6 190 86 117 <0.1
CEP-176........................... 42'' Steel Pipe Bearing.. 934 33 1,112 500 1,000 0.4
28'' Steel Sheet......... 773 28 921 414 2,512 2.4
CEP-102........................... 42'' Steel Pipe.......... 1,002 36 1,193 536 1,000 1.4
[[Page 3992]]
28'' Steel Sheet......... 773 28 921 414 2,512 8.0
24'' Concrete Pile....... 143 5 170 76 117 <0.1
18'' Concrete Pile....... 36 1 43 19 25 <0.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Area within the Level B threshold was calculated using geographic information system (GIS) data as determined by transmission loss modeling,
accounting for land.
Table 7--Level A and Level B Harassment Isopleths for Vibratory Pile Driving and Removal, and Pre-Drilling
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A--Radius to isopleth (m) Level B--Radius to isopleth
----------------------------------------------------------- (m)
-------------------------------
Pile driving site Source Area within
LF cetaceans MF cetaceans HF cetaceans Phocids Level B-- Level B
Radius to threshold
isopleth (m) (km\2\) \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pier 4............................ 14'' Timber (demolition). 20 2 30 12 6,310 49.9
24'' Concrete (vibratory) 5 <1 4 <1 6,310 97.8
24'' Concrete (drilling). 1 0 1 <1 1,848 4.4
Pier 3T........................... 16'' and 18'' Concrete 20 2 30 12 6,310 49.9
(demolition).
14'' Timber (demolition). 20 2 30 12 6,310 49.9
CEP-175........................... 13'' Polymeric 18 2 27 11 6,310 11.1
(vibratory).
13'' Polymeric (drilling) 1 <1 1 <1 1,848 4.4
CEP-176........................... 42'' Steel Pipe.......... 80 7 118 49 \2\ 15,849 46.0
28'' Steel Sheet......... 43 4 64 26 13,594 39.9
CEP-102........................... 42'' Steel Pipe.......... 80 7 118 49 15,849 98.9
28'' Steel Sheet......... 43 4 64 26 13,594 90.6
24'' Concrete (drilling). 1 0 1 <1 1,848 4.4
14'' Timber.............. 20 2 30 12 6,310 49.9
13'' Polymeric........... 20 2 30 12 6,310 49.9
18'' Concrete............ 20 2 29.7 12 6,310 49.9
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Area within the Level B threshold was calculated using geographic information system (GIS) data as determined by transmission loss modeling.
\2\ Note: This value is different than that listed in the application, due to a typographic error in the application. The correct maximum distance to
120 dB RMS threshold is 15,849 m as seen here.
The maximum distance to the Level A harassment threshold during
construction would be during the impact driving of 42-inch steel pipe
piles at CEP-102 (1,193 m for harbor porpoise; 1,001 m for humpback
whale; 35.6 m for bottlenose dolphin; and 536 m for pinnipeds). The
largest calculated Level B harassment zone extends out to 15,849 m,
which would result from the vibratory installation of the 42-inch steel
pipe pile.
Marine Mammal Occurrence and Take Calculation and Estimation
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations. We describe how the information provided above is brought
together to produce a quantitative take estimate for each species.
Humpback Whale
Humpback whales occur in the mouth of the Chesapeake Bay and
nearshore waters of Virginia during winter and spring months. Most
detections during shipboard surveys were one or two juveniles per
sightings. Although two individuals were detected in the vicinity of
proposed project activities, there is no evidence that they linger for
multiple days. Because no density estimates are available for the
species in this area, the Navy estimated two takes for every 60 days of
pile driving and drilling activities. Based on this information, NMFS
has similarly estimated that two humpback whales may be taken by Level
B harassment for every 60 days of pile driving and pre-drilling
activities, which equates to 9 takes over 280 project days (Table 1).
To be conservative, the Navy has requested 3 additional Level B
harassment takes of humpback whales. Therefore, the Navy is requesting,
and NMFS is proposing to authorize 12 takes by Level B harassment of
humpback whale (Table 9).
The largest Level A harassment zone for low-frequency cetaceans
extends approximately 1,002 m from the source during impact driving of
a 48 inch steel pipe pile (Table 6). The Navy is planning to implement
a 1,010 m shutdown zone for humpback whales during impact pile driving
of the 48 inch steel pipe piles, and shutdown zones that include the
entire Level A harassment isopleth for all activities, as indicated in
Table 10. Therefore, the Navy did not request, and NMFS does not
propose to authorize Level A harassment take of humpback whale.
Bottlenose Dolphin
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 (Engelhaupt et al., 2016). 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. NMFS multiplied the density of 1.38 dolphins/km\2\ by the Level B
harassment zone area for each activity for the project, and then by the
number of days associated with that activity (see Table 8), which
resulted in 14,989 takes by Level B harassment of bottlenose dolphins
(see Table 9). There
[[Page 3993]]
is insufficient information on relative abundance to apportion the
takes precisely to the three stocks present in the area. We use the
same approach to estimating the apportionment of takes to stock used in
the previous IHAs in the area including the HRBT project (86 FR 17458;
April 2, 2021), and the U.S. Navy Norfolk Rule (86 FR 24340; May 6,
2021). Given that most of the NNCES stock are found in the Pamlico
Sound Estuarine, over 160 kilometers to Norfolk, the project will
assume that no more than 200 of the requested takes will be from this
stock. Since members of the northern migratory coastal and southern
migratory coastal stocks are thought to occur in or near the Bay in
greater numbers, we will conservatively assume that no more than half
of the remaining takes will accrue to either of these stocks.
Additionally, a subset of these takes would likely be comprised of
Chesapeake Bay resident dolphins, although the size of that population
is unknown.
The largest Level A harassment area for mid-frequency cetaceans is
less than 40 m, which is associated with impact pile driving of the 42
inch steel pipe. The Navy is planning on implementing a shutdown zone
of 200 m during this activity as well as when pile driving the 24 inch
concrete piles and 28 inch steel sheet piles. The Level A harassment
zones for all other activities extend less than 10 m for mid-frequency
cetaceans (see Table 6 and Table 7), and the Navy is planning to
implement a minimum of a 10 m shutdown for all other activities not
included in the list above (Table 10). Given the generally small size
of the Level A harassment zones, and the Navy's shutdown plan, which
includes the entire Level A harassment zone for all pile driving and
drilling activities, we do not expect Level A harassment take of
bottlenose dolphins. Therefore, the Navy did not request, and NMFS does
not propose to authorize Level A harassment take of bottlenose dolphins
(Table 9).
Table 8--Bottlenose Dolphin Calculated Exposure Estimates
----------------------------------------------------------------------------------------------------------------
Level A Level B
Location Activity Production harassment harassment Level A Level B
days area (km\2\) area (km\2\) takes takes \1\
----------------------------------------------------------------------------------------------------------------
Pier 4................ Vibratory Removal 9 0.00001 49.9 0 620
Timber Fender Piles.
Pre-Drilling Concrete 6 0.000001 4.38 0 36
Fender Piles.
Impact Drive Concrete 3 0.0000813 0.04 0 0
Fender Piles.
CEP-175............... Impact Drive 2 0.000001 0.000014 0 0
Polymeric Fender
Piles.
Pre-Drilling 2 0.000004 4.38 0 * 12
Polymeric Fender
Piles.
Vibratory Drive 2 0.000004 11.1 0 31
Polymeric Fender
Piles.
Pier 3................ Impact Drive Concrete 150 0.00010155 0.04 0 8
Bearing Piles.
CEP-176............... Impact Drive Steel 55 0.00174582 0.41 0 * 31
Bearing Piles.
Impact Drive Sheet 55 0.00119976 2.43 0 * 184
Piles.
Vibratory Drive Steel 55 0.00008 45.97 0 3,489
Bearing Piles.
Vibratory Drive Sheet 56 0.000025 39.9 0 3,083
Piles.
CEP-102............... Impact Drive Steel 2 0.00245817 1.37 0 * 4
Bearing Piles.
Impact Drive Sheet 2 0.00154729 7.96 0 * 22
Piles.
Impact Drive Concrete 6 0.0000813 0.02 0 0
Bearing Piles.
Pre-Drilling Concrete 6 0.000001 4.38 0 36
Bearing Piles.
Vibratory Extraction 3 0.00001 49.9 0 207
Timber Fender Piles.
Vibratory Extraction 6 0.00001 49.9 0 413
Concrete Fender
Piles.
Vibratory Extraction 1 0.00001 49.9 0 69
Polymeric Fender
Piles.
Vibratory Drive Steel 2 0.000156 98.91 0 273
Bearing Piles.
Vibratory Drive Sheet 2 0.000045 90.6 0 250
Piles.
Pier 3T............... Vibratory Extraction 72 0.00001 49.9 0 4,958
Concrete Bearing
Piles.
Vibratory Extraction 22 0.00001 49.9 0 1,515
Timber Fender Piles.
----------------------------------------------------------------------------------------------------------------
Total Bottlenose Dolphin Take Estimate............................................ \2\ 0 \3\ 14,989
----------------------------------------------------------------------------------------------------------------
\1\ All Level and Level B harassment exposure estimates were calculated using a density estimate of 1.38
Engelhaupt et al. (2016).
\2\ The maximum distance to the Level A harassment threshold is 35.6 m resulting from impact driving 42-inch
steel pipe piles. This falls within the proposed shutdown zones (see Table 10). Therefore, no Level A
harassment take was requested nor proposed to be authorized for bottlenose dolphins.
\3\ Some piles for a few projects are listed twice, due to the contractor choosing the installation method.
However only the method resulting in the most takes was counted in the take totals. In all cases, vibratory
driving resulted in the most takes. Numbers with an asterisk indicate calculated takes that were excluded from
the total due to duplication.
Harbor Porpoise
Harbor porpoises are known to occur in the coastal waters near
Virginia Beach (Hayes et al., 2019). Density data for this species in
the project vicinity do not exist as harbor porpoise sighting data
collected by the U.S. 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).
Given the lack of density estimates for harbor porpoises in the
proposed construction area, this exposure analysis (similar to the
methods used in previous IHAs) assumes that there is a porpoise
sighting once every 60 days of pile driving or drilling, which would
equate to 6 sightings per year over 280 days of activity. Assuming an
average group size of two (Hansen et al., 2018; Elliser et al., 2018),
NMFS proposes to authorize 12 takes by Level B harassment of harbor
porpoises (Table 9).
Harbor porpoises are members of the high-frequency hearing group
which have Level A harassment isopleths as large as 1,193 m during the
42 inch steel pipe pile installation using impact pile driving. The
Navy has proposed a 500 meter shutdown zone for harbor porpoises during
the aforementioned activity in addition to impact pile driving the 24
inch concrete piles and 28 inch steel sheets, as a reasonable area to
observe and implement shutdowns for this small and cryptic species
while avoiding an impracticable number of shutdowns. Consequently, the
Navy has requested authorization of take by Level A harassment for
harbor porpoises during the project. While NMFS believes that take by
Level A harassment is not likely, due to the duration of time a harbor
porpoise would be required to remain within the Level A harassment
[[Page 3994]]
zone to accumulate enough energy to experience PTS, we propose to
authorize 10 takes by Level A harassment as requested by the Navy
(Table 9).
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 8 to 23
seals, with an average of 13.6 harbor seals across all the field
seasons.
The Navy expects, and NMFS concurs, that harbor seals are likely to
be present from November to April. Consistent with previous nearby
projects, NMFS calculated take by Level B harassment by multiplying
13.6 seals by 183, which is the number of pile driving/drilling days
expected to occur from November to April, which results in 2,489 harbor
seal takes. However, NMFS believes this may be an overestimate of take
as recent monitoring reports from a nearby-completed project observed 0
harbor seals during the course of their project (HRCP, Unpublished).
With these new data in hand, we propose to alter our estimation method
for this species and propose to authorize half of the take estimated
above to achieve a more realistic number of seals that may be
encountered, while still conservatively estimating noise exposures.
Therefore, NMFS proposes to authorize 1,244 takes of harbor seals.
The largest Level A harassment isopleth for phocid species is less
than 550 m, which would occur during the installation of the 42 inch
steel pipe pile by impact pile driving. We are proposing to implement a
200 m shutdown zone for this activity in addition to the installation
of the 24 inch concrete piles and 28 inch steel sheet piles by impact
pile driving (Table 10). Given the area of the Level A harassment zone
that would exceed the implemented shutdown zone for these activities,
and the cryptic nature of the species, the Navy is requesting 16 takes
by Level A harassment of harbor seals. For all other activities, the
proposed shutdown zones exceed the calculated Level A harassment
isopleth for phocid species. Therefore, NMFS proposes to authorize
1,228 takes by Level B harassment, and 16 takes by Level A harassment
of harbor seals (Table 9).
Gray Seal
Very little information is available about the occurrence of gray
seals in the Chesapeake Bay and coastal waters. Survey data collected
by the U.S. Navy at the CBBT portal islands from 2014 through 2018
(Rees et al., 2016; Jones et al., 2018) observed one gray seal in
February 2015 and one seal in February of 2016, while no seals were
observed at any other time. Maintaining the assumption that gray seals
may utilize the Chesapeake Bay waters, the Navy conservatively
estimates that one gray seal may be exposed to noise levels above the
Level B harassment threshold for every 60 days of vibratory pile
driving during the six month period when they are most likely to be
present.
The Level A harassment isopleth for phocids is noted above for
harbor seals, while the largest Level B harassment zone area is
anticipated during drilling for installation of the 42 inch steel pipes
(~16 km\2\). The Navy calculated a total of 3 exposures for gray seals
during the course of the project and they are expected to be very
uncommon in the Project area. It is anticipated that up to 20 percent
of gray seal exposures would be at or above the Level A harassment
threshold based on the proportion of the project's pile driving and
drilling activities that could exceed the Level A harassment threshold.
Therefore, the Navy is requesting, and NMFS is proposing to authorize,
1 take by Level A harassment and 2 takes by Level B harassment of gray
seals (Table 9).
Table 9--Proposed Authorized Amount of Taking, by Level A Harassment and Level B Harassment, by Species and Stock and Percent of Take by Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A Level B Percent of
Common name Stock harassment harassment Total stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale................................. Gulf of Maine \b\...................... 0 12 12 1
Bottlenose dolphin............................. WNA Coastal, Northern Migratory \a\ \c\ 0 19,327 19,327 111
\d\.
WNA Coastal, Southern Migratory \a\ \d\ 0 19,327 19,327 197
Northern NC Estuarine \a\ \c\ \d\...... 0 200 200 24
Harbor porpoise................................ Gulf of Maine/Bay of Fundy............. 10 12 22 <0.01
Harbor seal.................................... WNA.................................... 16 1,228 1,244 2
Gray seal...................................... WNA.................................... 1 2 3 <0.01
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Take estimates are weighted based on calculated percentages of population for each distinct stock, assuming animals present would follow same
probability of presence in the project area. Please see the Small Numbers section for additional information.
\b\ West Indies DPS. Please see the Description of Marine Mammals in the Area of Specified Activities section for further discussion.
\c\ Assumes multiple repeated takes of same individuals from small portion of each stock as well as repeated takes of Chesapeake Bay resident population
(size unknown). Please see the Small Numbers section for additional information.
\d\ The sum of authorized take for the three stocks of bottlenose dolphins does not add up to the total authorized number (14989) due to rounding.
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, and on
the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for 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, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or
[[Page 3995]]
stocks, and their habitat. This considers the nature of the potential
adverse impact being mitigated (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, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
The following mitigation measures are proposed in the IHA:
<bullet> Avoid direct physical interactions with marine mammals
during construction activity. If a marine mammal comes within 10 meters
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;
<bullet> The Navy will conduct trainings between construction
supervisors and crews and the marine mammal monitoring team prior to
the start of all activities subject to this IHA and when new personnel
join the work, to explain responsibilities, communication procedures,
marine mammal monitoring protocol, and operational procedures; and
<bullet> 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.
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 and drilling 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 (Table 9).
Protected Species Observers (PSOs)--The placement of PSOs during
all pile driving and removal and drilling activities (described in the
Proposed Monitoring and Reporting section) will ensure that the entire
shutdown zone is visible. Should environmental conditions deteriorate
such that the entire shutdown zone would not be visible (e.g., fog,
heavy rain), pile driving and removal and drilling must be delayed
until the PSO is confident marine mammals within the shutdown zone
could be detected.
Monitoring for Level A and B Harassment--The Navy will monitor the
Level B harassment zones to the extent practicable, and all of the
Level A harassment zones. The Navy will monitor at least a portion of
the Level B harassment zone on all pile driving, removal or drilling
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. The shutdown zone will be
considered cleared when a marine mammal has not been observed within
the zone for that 30-minute period. If a marine mammal is observed
within the shutdown zones listed in Table 10, pile driving and drilling
activity must be delayed or halted. If pile driving and/or drilling 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. When a marine
mammal for which Level B harassment take is authorized is present in
the Level B harassment zone, activities may begin and Level B
harassment take will be recorded. 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 start 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 10--Shutdown Zones (m) During Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
Humpback All other
Pile type, size, and driving method whales Porpoises species
----------------------------------------------------------------------------------------------------------------
Vibratory drive 14-inch timber piles............................ 30 30 30
Vibratory drive 13-inch polymeric piles......................... 30 30 30
Impact drive 13-inch polymeric piles............................ 30 30 30
Vibratory drive 16-inch and 18-inch concrete piles.............. 30 30 30
Impact drive 16-inch and 18-inch concrete piles................. 50 45 45
Vibratory drive 24-inch concrete piles.......................... 10 10 10
Impact drive 24-inch concrete piles............................. 160 500 200
Vibratory drive 28-inch steel sheet piles....................... 70 65 65
Impact drive 28-inch steel sheet piles.......................... 780 500 200
Vibratory drive 42-inch steel pipe piles........................ 80 120 50
Impact drive 42-inch steel pipe piles........................... 1,010 500 200
Pre-Drilling.................................................... 20 500 200
----------------------------------------------------------------------------------------------------------------
[[Page 3996]]
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
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 in the
proposed action area. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density).
<bullet> 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 action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors.
<bullet> How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks.
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat).
<bullet> Mitigation and monitoring effectiveness.
The Navy has submitted a Marine Mammal Monitoring Plan to NMFS that
has been approved for this project.
Visual Monitoring
Marine mammal monitoring during pile driving and removal and
drilling activities must be conducted by PSOs meeting NMFS' standards
and in a manner consistent with the following:
<bullet> Independent PSOs (i.e., not construction personnel) who
have no other assigned tasks during monitoring periods must be used;
<bullet> 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;
<bullet> Other PSOs may substitute education (degree in biological
science or related field) or training for experience; and
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator must be designated. The lead
observer must have prior experience working as a marine mammal observer
during construction.
PSOs must have the following additional qualifications:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
<bullet> 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.
The Navy must establish the following monitoring locations. For all
pile driving activities, a minimum of one PSO must be assigned to the
active pile driving or drilling location to monitor the shutdown zones
and as much of the Level A and Level B harassment zones as possible. If
the active project location includes demolition activities, then the
next adjacent pier may be used as an appropriate monitoring location
ensuring that the aforementioned criteria is met. Monitoring must be
conducted by a minimum of two PSOs for impact driving, and a minimum of
three PSOs for vibratory and drilling activities. For activities in
Table 7 with Level B harassment zones larger than 3000 m, at least one
PSO must be stationed on either Pier 14 or the North Jetty to monitor
the part of the zone exceeding the edge of the Norfolk Naval Station
(see Figure 3). The third PSO for vibratory and drilling activities
would be located on Pier 1. PSOs will be placed at the best vantage
point(s) practicable to monitor for marine mammals and implement
shutdown/delay procedures (See Figure 3 for representative monitoring
locations). If changes are necessary to ensure full coverage of the
Level A harassment zones, the Navy shall contact NMFS to alter observer
locations (e.g., vessel blocking view from pier location).
Monitoring will be conducted 30 minutes before, during, and 30
minutes 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 drilling or 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.
BILLING CODE 3510-22-P
[[Page 3997]]
[GRAPHIC] [TIFF OMITTED] TN26JA22.004
BILLING CODE 3510-22-C
Acoustic Monitoring
The Navy intends to conduct a sound source verification (SSV) study
for various types of pile driving, extraction, and drilling associated
with this proposed project. Monitoring shall include two underwater
positions and shall be conducted in accordance with NMFS guidance (NMFS
2012). One underwater location shall be at the standard 10 meters from
the sound source, while the other positions shall be located at a
distance of at least 20 times water depth at the pile. If the
contractor determines that this distance interferes with shipping lanes
for vessel traffic, or if there is no other reasons why this criteria
cannot be achieved (e.g., creates an unsafe scenario for crew), the
Navy's Acoustic Monitoring Plan must offer an alternate site as close
to the criteria as possible for NMFS' approval. Measurements shall be
collected as detailed in the Navy's application (Table 13-1) for each
pile type during the entire pile-driving/extraction/drilling event.
Monitoring shall be conducted for 10 percent of each type of activity
that has not previously been monitored at NAVSTA Norfolk (See Table 11
for complete list).
Table 11--Acoustic Monitoring Summary
----------------------------------------------------------------------------------------------------------------
Number
Pile type \1\ Count \2\ Method of install/removal \2\ monitored \2\
----------------------------------------------------------------------------------------------------------------
13-inch polymeric.......................... 14 Vibratory.......................... 5
13-inch polymeric.......................... 14 Impact............................. 5
13-inch polymeric.......................... 14 Drilling........................... 5
16- or 18-inch concrete.................... 308 Vibratory.......................... 10
24-inch concrete........................... 47 Impact............................. 10
42-inch steel pipe......................... 113 Vibratory.......................... 10
42-inch steel pipe......................... 113 Impact............................. 10
28-inch steel sheet........................ 229 Vibratory.......................... 10
28-inch steel sheet........................ 229 Impact............................. 10
----------------------------------------------------------------------------------------------------------------
\1\ Data has previously been collected on the impact driving of 24-inch concrete piles and timber piles at
NAVSTA Norfolk; therefore, no additional data collection is required for these pile types.
[[Page 3998]]
\2\ Some piles may be either vibratory or impact pile driving, or a combination of both. The acoustic monitoring
report at the end of Year 1 construction shall clarify which installation method was utilized and monitored
for each pile type.
Environmental data shall be collected, including but not limited
to, the following: Wind speed and direction, air temperature, humidity,
surface water temperature, water depth, wave height, weather
conditions, and other factors that could contribute to influencing
underwater sound levels (e.g., aircraft, boats, etc.).
Reporting
A draft marine mammal monitoring report and a draft acoustic
monitoring report will be submitted to NMFS within 90 days after the
completion of pile driving and removal and drilling activities, or 60
days prior to a requested date of issuance of any future IHAs or LOAs
for the project, or other projects at the same location, whichever
comes first. If the Navy goes ahead with their plan to request
incidental take authorization for future phases of this project, the
future LOA will be requested for coverage beginning on April 1, 2023;
the draft reports under this proposed IHA must be submitted to NMFS by
January 31, 2023. The marine mammal report will include an overall
description of work completed, a narrative regarding marine mammal
sightings, and associated PSO data sheets. Specifically, the report
must include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring.
<bullet> 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 hole
(drilling) and number of strikes for each pule (impact driving);
<bullet> PSO locations during marine mammal monitoring; and
<bullet> 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:
<bullet> Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting;
<bullet> Time of sighting;
<bullet> 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;
<bullet> Distance and location of each observed marine mammal
relative to the pile being driven or hole being drilled for each
sighting;
<bullet> Estimated number of animals (min/max/best estimate);
<bullet> Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.);
<bullet> 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);
<bullet> Number of marine mammals detected within the harassment
zones, by species; and
<bullet> 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:
<bullet> Hydrophone equipment and methods: Recording device,
sampling rate, distance (m) from the pile where recordings were made;
depth of water and recording device(s);
<bullet> 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;
<bullet> 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;
<bullet> For impact pile driving and/or drilling (per pile): Number
of strikes and strike rate; depth of substrate to penetrate; pulse
duration and mean, median, and maximum sound levels (dB re: 1
[micro]Pa): Root mean square sound pressure level (SPL<INF>rms</INF>);
cumulative sound exposure level (SEL<INF>cum</INF>), peak sound
pressure level (SPL<INF>peak</INF>), and single-strike sound exposure
level (SEL<INF>s-s</INF>); and
<bullet> For vibratory driving/removal and/or drilling (per pile):
Duration of driving per pile; mean, median, and maximum sound levels
(dB re: 1 [micro]Pa): Root mean square sound pressure level
(SPL<INF>rms</INF>), cumulative sound exposure level
(SEL<INF>cum</INF>) (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.
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the Navy must immediately
cease the specified activities and shall report the incident to the
Office of Protected Resources (OPR) (<a href="/cdn-cgi/l/email-protection#7424265a3d20245a391b1a1d001b061d1a132611041b060007341a1b15155a131b02"><span class="__cf_email__" data-cfemail="c39391ed8a9793ed8eacadaab7acb1aaada491a6b3acb1b7b083adaca2a2eda4acb5">[email protected]</span></a>)
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.
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
[[Page 3999]]
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 responses
(e.g., intensity, duration), the context of any responses (e.g.,
critical reproductive time or location, migration), 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's implementing regulations (54 FR
40338; September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the environmental baseline (e.g., as reflected in the
regulatory status of the species, population size and growth rate where
known, ongoing sources of human-caused mortality, or ambient noise
levels).
Pile driving and removal and drilling activities have the potential
to disturb or displace marine mammals. Specifically, the project
activities may result in take, in the form of Level A and Level B
harassment from underwater sounds generated from pile driving and
removal and drilling. Potential takes could occur if individuals are
present in the ensonified zone when these activities are underway.
The takes from Level A and Level B harassment would be due to
potential behavioral disturbance, TTS, and PTS. No serious injury or
mortality is anticipated given the nature of the activity and measures
designed to minimize the possibility of injury to marine mammals. The
potential for harassment is minimized through the construction method
and the implementation of the planned mitigation measures (see Proposed
Mitigation section).
The Level A harassment zones identified in Tables 6 and 7 are based
upon an animal exposed to pile driving or drilling multiple piles per
day. Considering the short duration to impact drive each pile and
breaks between pile installations (to reset equipment and move pile
into place), means an animal would have to remain within the area
estimated to be ensonified above the Level A harassment threshold for
multiple hours. This is highly unlikely given marine mammal movement
throughout the area, especially for small, fast moving species such as
small cetaceans and pinnipeds. Additionally, no Level A harassment is
anticipated for humpback whales due to the proposed mitigation
measures, which we expect the Navy will be able to effectively
implement given the small Level A harassment zone sizes and high
visibility of humpback whales. If an animal was exposed to accumulated
sound energy, the resulting PTS would likely be small (e.g., PTS onset)
at lower frequencies where pile driving energy is concentrated, and
unlikely to result in impacts to individual fitness, reproduction, or
survival.
The Navy's proposed pile driving project precludes the likelihood
of serious injury or mortality. For all species and stocks, take would
occur within a limited, confined area (immediately surrounding NAVSTA
Norfolk in the Chesapeake Bay area) of the stock's range. Level A and
Level B harassment will be reduced to the level of least practicable
adverse impact through use of mitigation measures described herein.
Furthermore, the amount of take proposed to be authorized is extremely
small when compared to stock abundance.
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, or decreased
foraging (if such activity were occurring) (e.g., Thorson and Reyff
2006). 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 or drilling, although even this reaction
has been observed primarily only in association with impact pile
driving. The pile driving and drilling 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 sound produced by project activities is sufficiently
disturbing, animals are likely to simply avoid the area while the
activity is occurring, particularly as the project is located on a busy
waterfront with high amounts of vessel traffic.
As previously described, UMEs have been declared for Northeast
pinnipeds (including harbor seal and gray seal) and Atlantic humpback
whales. However, we do not expect takes proposed for authorization in
this action to exacerbate or compound upon these ongoing UMEs. As noted
previously, no injury, serious injury, or mortality is expect or
proposed for authorization, and Level B harassment takes of humpback
whale, harbor seal and gray seal will be reduced to the level of least
practicable adverse impact through the incorporation of the proposed
mitigation measures. For the WNA stock of gray seal, the estimated
stock abundance is 451,600 animals. Given that only 1 to 3 takes by
Level B harassment are proposed for this stock annually, we do not
expect this proposed authorization to exacerbate or compound upon the
ongoing UME.
For the WNA stock of harbor seals, the estimated abundance is
61,336 individuals. The estimated M/SI for this stock (339) is well
below the PBR (1,729). As such, the proposed Level B harassment takes
of harbor seal are not expected to exacerbate or compound upon the
ongoing UMEs.
With regard to humpback whales, the UME does not yet provide cause
for concern regarding population-level impacts. Despite the UME, the
relevant population of humpback whales (the Gulf of Maine stock and the
West Indies breeding population, or distinct population segment (DPS))
remains healthy. The Gulf of Marine stock of humpback whales was listed
as strategic under the MMPA from 1995 through the 2018 SARs but has
since been removed from this list. Annual SARs have also indicated an
increasing population trend for the stock, with a current abundance
estimate of 1369 whales (Hayes et al., 2021).
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 DPSs with different
listing statuses (81 FR 62259; September 8, 2016) pursuant to the ESA.
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, was delisted. The status
review identified harmful algal blooms, vessel collisions, and fishing
gear entanglements as relevant threats for this DPS, but noted that all
other threats are considered likely to have no or minor impact on
population size or the growth rate of this DPS (Bettridge et al.,
2015). As described in Bettridge et al.,
[[Page 4000]]
(2015), the West Indies DPS has a substantial population size (i.e.,
12,312 (95 percent CI 8,688-15,954) whales in 2004-05 (Bettridge et
al., 2003)), and appears to be experiencing consistent growth. This
trend is consistent with that in 2021 draft SARs as mentioned above.
Further, NMFS is proposing to authorize no more than eight takes by
Level B harassment annually of humpback whale.
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; but, 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 the species or stock
through effects on annual rates of recruitment or survival:
<bullet> No mortality is anticipated or authorized;
<bullet> Authorized Level A harassment would be very small amounts
and of low degree;
<bullet> The intensity of anticipated takes by Level B harassment
is relatively low for all stocks;
<bullet> The number of anticipated takes is very low for humpback
whale, harbor porpoise, and gray seal;
<bullet> The specified activity and associated ensonifed areas are
very small relative to the overall habitat ranges of all species and do
not include habitat areas of special significance (Biologically
Important Areas or ESA-designated critical habitat);
<bullet> The lack of anticipated significant or long-term negative
effects to marine mammal habitat;
<bullet> The presumed efficacy of the mitigation measures in
reducing the effects of the specified activity; and
<bullet> Monitoring reports from similar work in the Chesapeake Bay
have documented little to no effect on individuals of the same species
impacted by the specified 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 above, only small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is 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 amount of take NMFS proposes to authorize is below one third of
the estimated stock abundance for humpback whale, harbor porpoise, gray
seal, the Northern North Carolina Estuarine Stock of bottlenose dolphin
and harbor seal (in fact, take of individuals is less than 5 percent of
the abundance of the affected stocks, see Table 9). This is likely a
conservative estimate because they assume all takes are of different
individual animals which is likely not the case. Some individuals may
return multiple times in a day, but PSOs would count them as separate
takes if they cannot be individually identified.
There are three bottlenose dolphin stocks that could occur in the
project area. Therefore, the estimated 14,989 dolphin takes by Level B
harassment would likely be split among the western North Atlantic
northern migratory coastal stock, the western North Atlantic 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, representing 24 percent of that population, with the
remaining takes split evenly between the northern and southern
migratory coastal stocks. Based on the consideration of various factors
as described below, we have determined the number of individuals taken
would comprise less than one-third of the best available population
abundance estimate of either coastal migratory stocks. Detailed
descriptions of the stocks' ranges have been provided in the
Description of Marine Mammals in the Area of Specified Activities
section.
Both the northern migratory coastal and southern migratory coastal
stocks have expansive ranges and they are the only dolphin stocks
thought to make broad-scale, seasonal migrations in coastal waters of
the western North Atlantic. 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 northern migratory coastal stock is found
during warm water months from coastal Virginia, including the
Chesapeake Bay and Long Island, New York. The stock migrates south in
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 January-March, the southern Migratory
coastal 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 northern and southern migratory stocks during spring and
fall migrations, but the extent of overlap is unknown.
The Chesapeake Bay and waters offshore of the mouth are located on
the periphery of the migratory ranges of both coastal stocks (although
during different seasons). Additionally, each of the migratory coastal
stocks are likely to be located in the vicinity of the Bay for
relatively short timeframes. Given the limited number of animals from
each migratory coastal stock likely to be found at the seasonal
migratory boundaries of their respective ranges, in combination with
the short time periods (~2 months) animals might remain at these
boundaries, it is reasonable to assume that takes are likely to occur
only within some small portion of either of the migratory coastal
stocks.
[[Page 4001]]
Many of the dolphin observations in the Bay are likely repeated
sightings of the same individuals. The Potomac-Chesapeake Dolphin
Project has observed over 1,200 unique animals since observations began
in 2015. Re-sightings of the same individual can be highly variable.
Some dolphins are observed once per year, while others are highly
regular with greater than 10 sightings per year (Mann, Personal
Communication). Similarly, using available photo-identification data,
Engelhaupt et al. (2016) determined that specified individuals were
often observed in close proximity to their original sighting locations
and were observed multiple times in the same season or same year.
Ninety-one percent of re-sighted individuals (100 of 110) in the study
area were recorded less than 30 km from the initial sighting location.
Multiple sightings of the same individual would considerably reduce the
number of individual animals that are taken by harassment. Furthermore,
the existence of a resident dolphin population in the Bay would
increase the percentage of dolphin takes that are actually re-sightings
of the same individuals.
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:
<bullet> The take of marine mammal stocks authorized for take
comprises less than 5 percent of any stock abundance (with the
exception of the Northern and Southern Migratory stocks of bottlenose
dolphin);
<bullet> Potential bottlenose dolphin takes in the project area are
likely to be allocated among three distinct stocks;
<bullet> 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;
<bullet> 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
<bullet> Many of the takes would likely be repeats of the same
animals and likely 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 will 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.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue an IHA to the U.S. Navy for conducting pile driving and drilling
activities associated with the demolition and reconstruction of Pier 3
at Naval Station Norfolk, in Norfolk, Virginia from April 1, 2022
through March 31, 2023, provided the previously mentioned mitigation,
monitoring, and reporting requirements are incorporated. A draft of the
proposed IHA can be found at <a href="https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a>.
Request for Public Comments
We request comment on our analyses, the proposed authorization, and
any other aspect of this notice of proposed IHA for the proposed Pier 3
project. We also request at this time comment on the potential renewal
of this proposed IHA as described in the paragraph below. Please
include with your comments any supporting data or literature citations
to help inform decisions on the request for this IHA or a subsequent
Renewal IHA.
On a case-by-case basis, NMFS may issue a one-time, one-year
Renewal IHA following notice to the public providing an additional 15
days for public comments when (1) up to another year of identical or
nearly identical, or nearly identical, activities as described in the
Description of Proposed Activities section of this notice is planned or
(2) the activities as described in the Description of Proposed
Activities section of this notice would not be completed by the time
the IHA expires and a renewal would allow for completion of the
activities beyond that described in the Dates and Duration section of
this notice, provided all of the following conditions are met:
<bullet> A request for renewal is received no later than 60 days
prior to the needed Renewal IHA effective date (recognizing that the
Renewal IHA expiration date cannot extend beyond one year from
expiration of the initial IHA).
<bullet> The request for renewal must include the following:
(1) An explanation that the activities to be conducted under the
requested Renewal IHA are identical to the activities analyzed under
the initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take).
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for renewal, the status of the affected
species or stocks, and any other pertinent information, NMFS determines
that there are no more than minor changes in the activities, the
mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: January 20, 2022.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2022-01474 Filed 1-25-22; 8:45 am]
BILLING CODE 3510-22-P
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