Notice2024-16753
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Washington State Department of Transportation's Seattle Slip 3 Vehicle Transfer Span Project in Washington State
Primary source
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Published
July 30, 2024
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from Washington State Department of Transportation (WSDOT) for authorization to take marine mammals incidental to Seattle Slip 3 Vehicle Transfer Span (VTS) Replacement Project in Seattle, Washington. 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, 1-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 authorization and agency responses will be summarized in the final notice of our decision.
Full Text
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<title>Federal Register, Volume 89 Issue 146 (Tuesday, July 30, 2024)</title>
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[Federal Register Volume 89, Number 146 (Tuesday, July 30, 2024)]
[Notices]
[Pages 61064-61087]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-16753]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE018]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Washington State Department of
Transportation's Seattle Slip 3 Vehicle Transfer Span Project in
Washington State
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 Washington State Department
of Transportation (WSDOT) for authorization to take marine mammals
incidental to Seattle Slip 3 Vehicle Transfer Span (VTS) Replacement
Project in Seattle, Washington. 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, 1-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 authorization and agency
responses will be summarized in the final notice of our decision.
DATES: Comments and information must be received no later than August
29, 2024.
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#6e273a3e400a0b030f1c0b1d1a2e00010f0f40090118"><span class="__cf_email__" data-cfemail="723b26225c16171f1300170106321c1d13135c151d04">[email protected]</span></a>. 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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>. In case of problems accessing these documents,
please call the contact listed below.
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="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> without change. All personal identifying
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: Austin Demarest, Office of Protected
Resources, NMFS, (301) 427-8401.
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 proposed or, if the taking is limited to harassment, a notice of a
proposed IHA is provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth. 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 NAO 216-6A, which do not
individually or cumulatively have the potential for significant impacts
on the quality of the human environment and for which we have not
identified any extraordinary circumstances that would preclude this
categorical exclusion. Accordingly, NMFS has preliminarily determined
that the issuance of the proposed 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 December 19, 2023, NMFS received a request from WSDOT for an IHA
to take marine mammals incidental to Seattle Slip 3 VTS Replacement
Project in Elliott Bay of the Puget Sound, Seattle, WA. Following NMFS'
review of the application, WSDOT submitted revised versions on March 4,
April 8, April 18, and April 29, 2024. A final revised monitoring plan
was
[[Page 61065]]
submitted on May 14, 2024 and a final revised application was submitted
on May 16, 2024. The application was deemed adequate and complete on
May 20, 2024. WSDOT's request is for take of 12 species of marine
mammals, by Level B harassment only. Neither WSDOT nor NMFS expect
serious injury or mortality to result from this activity and,
therefore, an IHA is appropriate.
Description of Proposed Activity and Anticipated Impacts
Overview
WSDOT is proposing to replace the Seattle Slip 3 VTS at Colman Dock
which is located in Elliott Bay of the Puget Sound in Seattle,
Washington. The purpose of the construction project is to preserve the
transportation function of an aging, seismically deficient transfer
span. The existing VTS will be removed and replaced with a hydraulic
transfer span consisting of steel drilled shafts and a new steel
wingwall. In-water construction includes cutting sheet piles,
installation and removal of steel piles with a vibratory hammer, and
proofing steel piles with an impact hammer to drive them to the maximum
depth and ensure load bearing capacity. In-water pile removal and
driving with vibratory and impact hammers may result in incidental take
by Level B harassment of 12 marine mammal species within Elliott Bay
and the Central Puget Sound. The effective construction window for the
project, which is expected to require a maximum of 19 days, is from
August 1, 2024 through February 15, 2025. Replacement of the Seattle
Slip 3 VTS will allow WSDOT to continue to provide safe and reliable
transportation services throughout the Puget Sound and San Juan
Islands.
Dates and Duration
Construction for the Seattle Slip 3 VTS Replacement Project has an
effective work window from August 1, 2024 through February 15, 2025 to
avoid when ESA listed salmonids are most likely to be present. A
maximum of 19 in-water construction days will occur, which includes a
flexibility for adverse weather conditions and equipment malfunction.
Operation hours for in-water construction will occur during daylight
hours from sunrise to sunset but will be contingent upon weather
conditions with good visibility. The IHA would be valid for 1 year from
the date of issuance.
Specific Geographic Region
Seattle Slip 3 VTS Replacement Project is part of the Seattle Ferry
Terminal at Colman Dock and located along the Seattle waterfront in
Elliott Bay (Figures 1 and 2). Elliott Bay is an urban embayment that
is approximately 8 square miles (mi\2\) (21 square kilometers (km\2\)),
central in the Puget Sound, Washington. The Seattle waterfront is
highly urbanized with residential, business, and industrial areas
including the Port of Seattle container loading facility, the Pioneer
Square Historic District, and local parks.
BILLING CODE 3510-22-P
[[Page 61066]]
[GRAPHIC] [TIFF OMITTED] TN30JY24.003
[[Page 61067]]
[GRAPHIC] [TIFF OMITTED] TN30JY24.004
BILLING CODE 3510-22-C
Detailed Description of the Specified Activity
Removal of the existing VTS and wingwall pile includes the
extraction of 16 14-inch steel H-piles with a vibratory hammer and
removal of a 30-inch concrete filled wingwall pile that would be cut at
or below the mudline. Following removal of the VTS, 12 24-inch steel
piles would be temporarily installed via a vibratory hammer and proofed
with an impact hammer to confirm load bearing capacity for a temporary
work platform. WSDOT would then permanently install 2 78-inch hollow
steel drilled shafts via vibratory hammer. All the materials inside the
78-inch steel shafts would be extracted with an auger or clamshell
bucket and then dewatered for the hydraulic VTS. A 30-inch steel wing
wall pile would then be installed with a vibratory hammer and then the
12 24-inch temporary steel piles would be extracted via a vibratory
hammer which concludes in-water construction. Table 1 provides a
summary of the number of piles that would be removed and installed, the
driving method, pile size, number of piles per day, time needed to
drive each pile, and the maximum number of days needed to complete the
Seattle Slip 3 VTS Replacement Project.
Pile driving activities described above may result in Level B
harassment of marine mammals in Elliott Bay and the central Puget Sound
to the eastern shore of Bainbridge Island. Cutting the 30-inch wingwall
pile and removal of the material from inside the 78-inch piles is
expected to produce negligible in-water sound, which is unlikely to
cause any incidental take of marine mammals. In-water construction
would be a
[[Page 61068]]
maximum of 19 days from August 1, 2024 through February 15, 2025. The
Seattle Slip 3 VTS Replacement Project would not use multiple hammers
for installation or removal concurrently but vibratory and impact
hammer could be used on the same day.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS' Stock Assessment Reports (SARs; <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' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 1--Summary of Piles To Be Installed and Removed for the Seattle Slip 3 VTS Replacement Project
--------------------------------------------------------------------------------------------------------------------------------------------------------
Duration
Pile size and type Method Install or remove Number of Piles per day per pile Duration
piles (24 hours) (minutes) (days)
--------------------------------------------------------------------------------------------------------------------------------------------------------
78-inch steel........................... Vibratory.................. Install................... 2 1 60 2
30-inch steel........................... Vibratory.................. Install................... 1 1 60 1
24-inch steel........................... Vibratory.................. Install................... 12 3 30 4
24-inch steel........................... Impact..................... Install................... 12 3 30 4
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Subtotal............................ ........................... .......................... ........... .............. ........... 11
24-inch steel........................... Vibratory.................. Remove.................... 12 3 30 4
14-inch steel........................... Vibratory.................. Remove.................... 16 4 30 4
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Subtotal............................ ........................... .......................... ........... .............. ........... 8
---------------------------------------------------------------------------------------------------------------
Total........................... ........................... .......................... ........... .............. ........... 19
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Table 2 lists all species or stocks for which take is expected and
proposed to be authorized for this activity and summarizes information
related to the population or stock, including regulatory status under
the MMPA and Endangered Species Act (ESA) and potential biological
removal (PBR), where known. PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS'
SARs). While no serious injury or mortality is anticipated or proposed
to be authorized here, PBR and annual serious injury and mortality from
anthropogenic sources are included here as gross indicators of the
status of the species or stocks and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. Survey abundance (as compared to stock or species
abundance) is the total number of individuals estimated within the
survey area, which may or may not align completely with a stock's
geographic range as defined in the SARs. For some species, this
geographic area or surveys may extend beyond U.S. waters. All managed
stocks in this region are assessed in NMFS' U.S. Pacific and Alaska
SARs. All values presented in table 2 are the most recent available at
the time of publication (including from the draft 2023 SARs) and are
available 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>.
Table 2--Species Likely Impacted by the Specified Activities
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ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey) \3\ SI \4\
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Order Artiodactyla--Cetacea--Mysticeti (baleen whales)
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Family Eschrichtiidae:
Gray whale...................... Eschrichtius robustus.. Eastern N Pacific...... -, -, N 26,960 (0.05, 25,849, 801 131
2016).
Minke whale..................... Balaenoptera CA/OR/WA............... -, -, N 915 (0.792, 509, 2018) 4.1 0.19
acutorostrata.
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Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Killer whale \5\................ Orcinus orca........... West Coast Transient... -, -, N 349 (N/A, 349, 2018).. 3.5 0.4
Bottlenose dolphin.............. Tursiops truncatus..... CA/OR/WA offshore...... -, -, N 3,477 (0.696, 2,048, 19.70 >=0.82
2018).
Long beaked common dolphin...... Delphinus capensis..... CA..................... -, -, N 83,379 (0.216, 69,636, 668 >=29.7
2018).
Pacific white-sided Dolphin..... Lagenorhynchus CA/OR/WA............... -, -, N 34,999 (0.222, 29,090, 279 7
obliquidens. 2018).
Family Phocoenidae (porpoises):
[[Page 61069]]
Dall's porpoise................. Phocoenoides dalli..... CA/OR/WA............... -, -, N 16,498 (0.61, 10,286, 99 >=0.66
2018).
Harbor porpoise................. Phocoena phocoena...... Washington Inland -, -, N 11,233 (0.37, 8,308, 66 >=7.2
Waters. 2015).
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Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
CA sea lion..................... Zalophus californianus. U.S.................... -, -, N 257,606 (N/A, 233,515, 14,011 >321
2014).
Steller sea lion \6\............ Eumetopias jubatus..... Eastern................ -, -, N 36,308 (N/A, 36,308, 2,178 93.2
2022).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... Washington Northern -, -, N 16,451 (0.07, 15,462, 928 40
Inland Waters. 2019).
Northern elephant seal \7\...... Mirounga angustirostris CA Breeding............ -, -, N 187,386 (N/A, 85,369, 5,122 13.7
2013).
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\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
(<a href="https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>; Committee on Taxonomy (2022)).
\2\ ESA status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed under the ESA or
designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality exceeds PBR or
which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed under the ESA is
automatically designated under the MMPA as depleted and as a strategic stock.
\3\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports-region</a>. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, 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.
\5\ Nest is based upon count of individuals identified from photo-ID catalogs in analysis of a subset of data from 1958-2018.
\6\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys. Estimates provided are for the U.S.
only.
\7\ There is uncertainty in available population estimates due to limited surveys, limited reproductive data, and uncertainty in stock relationships and
harvest statistics.
As indicated above, all 12 species in table 2 spatially and
temporally co-occur with the activity to the degree that take is
reasonably likely to occur. All species that could potentially occur in
the proposed project areas are included in table 3 of the IHA
application. While southern resident killer whales (SRKW), and humpback
whales (HW) (Central America/Southern Mexico--California-Oregon-
Washington, Mainland Mexico--California-Oregon-Washington, and Hawaii
stocks) have been documented in the area, the temporal and/or spatial
occurrence of these species is such that take is not expected to occur,
and they are not discussed further beyond the explanation provided
here.
Generally SRKWs are considered common in the Puget Sound (Olson et
al., 2018). During the Seattle Multimodal Project 170 observations of
SRKWs occurred over 377 construction days. Although SRKWs are
relatively common in the construction area, WSDOT has expertise with
monitoring for SRKWs and halting construction when they approach or
enter established shutdown zones. For the Seattle Slip 3 VTS
Replacement Project, WSDOT would establish shutdown zones for SRKWs at
the estimated Level B harassment zones rounded up to the nearest 50
meters. WSDOT would also monitor marine mammal occurrence and movement
with the Orca Network and the Whale Report Alert System (WRAS) networks
daily for this project. Considering SRKWs frequency of occurrence in
the project area and WSDOTs experience mentioned above, take of SRKW is
not expected.
The occurrence of HWs in Puget Sound is considered common with the
greatest density of sightings off the south end of Vancouver Island in
the Strait of Juan de Fuca (Olsen et al., 2024). During the Seattle
Multimodal Project 8 observations of HWs occurred over 377 construction
days. Since the Seattle Slip 3 VTS Replacement Project is in the same
area, HW occurrence in the construction area is expected to be rare.
WSDOT would establish shutdown zones and monitor marine mammal
occurrence and movement for HWs (identical to the measures described
above for SRKWs). Therefore take of HWs in not expected. Details about
mitigation measures, shutdown zones, and protected species observers
(PSOs) can be found in the Proposed Mitigation and the Proposed
Monitoring and Reporting sections below.
Due to these mitigation measures and these species being highly
conspicuous, incidental take of SRKWs or HWs is not expected for the
duration of this project.
Gray Whale
Generally, the Eastern North Pacific stock of gray whales feed in
the Arctic in summer and fall months and then breed during winter and
spring months off the coast of Mexico (Carretta et al. 2022,
Calambokidis et al. 2024). During migration from Mexico to the Arctic,
a subpopulation of the Eastern North Pacific stock of Gray whales,
commonly referred to as the Pacific Coast Feeding Group (PCFG), stop
and feed along the coasts of Oregon and Washington including the
Northern Puget Sound (Calambokidis et al. 2024). A subgroup of the PCFG
that feed in the Puget Sound, recently termed as ``Sounders'' gray
whales, are the most abundant from February through May. The highest
concentrations Sounders Gray Whales occurs on the Southern ends of
Whidbey and Camano Islands in the North Puget Sound (Calambokidis et
al. 2024). Although Sounders gray whale observations are the highest in
the Northern Puget Sound but observations also occur in the Southern
Puget Sound and Elliott Bay, which is in the proposed action area (Orca
Network, 2021).
There are Biologically Important Areas (BIAs) for migrating gray
whales in the inland waters of the Northern Puget Sound from January
through July and October through December and for feeding gray whales
between February and June (Calambokidis et al., 2015; Calambokidis et
al., 2024).
The NMFS declared an unusual mortality event (UME) for gray whales
on May 30, 2019 after elevated numbers of strandings occurred along the
Pacific coast of North America, The UME started December 17, 2018 and
was closed on November 9, 2023, with peak standings occurring from
December 17, 2018 through December 31, 2020. The
[[Page 61070]]
UME included 690 gray whale standings, 347 in the United States, 316 in
Mexico, and 27 in Canada. Necropsies were performed on a subset of the
dead whales and malnutrition was common followed by evidence of killer
whale predation, entanglement, vessel strikes, and biotoxins were found
in some carcasses as in years without UMEs. NMFS concluded that the
nutritional conditions of live gray whales was lower prior to and
during the UME. Gray whale abundance declined and calf production
decline following the UME but calf production has begun to rebound.
Additional information about this UME can be found at <a href="https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2023-eastern-north-pacific-gray-whale-ume-closed">https://www.fisheries.noaa.gov/national/marine-life-distress/2019-2023-eastern-north-pacific-gray-whale-ume-closed</a>.
Minke Whale
The International Whaling Commission (IWC) recognizes three stocks
of minke whales in the North Pacific: The Sea of Japan/East China Sea,
the rest of the western Pacific west of 180[deg] N, and the remainder
of the Pacific (Donovan 1991). Minke whales are relatively common in
the Bering and Chukchi seas and in the Gulf of Alaska, but are not
considered abundant in any other part of the eastern Pacific
(Brueggeman et al., 1990). In the far north, minke whales are thought
to be migratory, but they are believed to be year-round residents in
coastal waters off the west coast of the United States (Dorsey et al.,
1990).
Minke whales are reported in Washington inland waters year-round,
although few are reported in the winter (i.e., during the anticipated
in-water work window for these projects; Calambokidis and Baird 1994).
They are relatively common in the San Juan Islands and Strait of Juan
de Fuca (especially around several of the banks in both the central and
eastern Strait), but are relatively rare in Puget Sound and the Orca
Network has no sighting records of minke whales in the project areas.
Although minke whales are considered rare within the Puget Sound, three
minke whales were observed during the Seattle Multimodal Project during
the 377 days of marine mammal monitoring from 2017-2021.
Killer Whale
There are three distinct ecotypes, or forms, of killer whales
recognized in the north Pacific: resident, transient, and offshore. The
three ecotypes differ morphologically, ecologically, behaviorally, and
genetically. Resident killer whales exclusively prey upon fish, with a
clear preference for salmon (Ford and Ellis 2006; Hanson et al., 2021;
Ford et al., 2016), while transient killer whales exclusively prey upon
marine mammals (Caretta et al., 2019). Less is known about offshore
killer whales, but they are believed to consume primarily fish,
including several species of shark (Dahlheim et al., 2008). Currently,
there are eight killer whale stocks recognized in the U.S. Pacific
(Carretta et al., 2021; Muto et al., 2021). Of those, individuals from
the West Coast Transient stock may occur in the project areas and be
taken incidental to WSDOT's proposed activities.
Within Puget Sound, transient killer whales primarily hunt
pinnipeds and porpoises, though some groups will occasionally target
larger whales. The West Coast Transient stock of killer whales occurs
from California through southeast Alaska (Muto et al., 2021). The
seasonal movements of transients are largely unpredictable, although
there is a tendency to investigate harbor seal haulouts off Vancouver
Island more frequently during the pupping season in August and
September (Baird 1995; Ford 2014). Transient killer whales have been
observed in central Puget Sound in all months (Orca Network 2021).
During WSDOTs Seattle Multimodal Project, 79 transient killer whales
were observed throughout the 377 days of in water work from 2017
through 2021 with a maximum of 20 individuals observed on a single day.
Bottlenose Dolphin
Bottlenose dolphins are distributed worldwide from approximately
45[deg] N to 45[deg] S. Bottlenose dolphins inhabiting west coast U.S.
waters are considered to be in either the California coastal stock,
which ranges from Mexico to the San Francisco area within approximately
1 kilometer of shore, or the California/Oregon/Washington offshore
stock, which is most commonly found along the California coast,
northward to about the Oregon border. NMFS offshore surveys from 1991
to 2014 resulted in no sightings during study transects off the Oregon
or Washington coasts (Carretta et al., 2019). In September 2017,
however, multiple sightings of a bottlenose dolphin throughout the
Puget Sound and in Elliott Bay were reported to Cascadia Research
Collective and Orca Network. One of the individuals was identified as
belonging to the California coastal stock (Cascadia Research
Collective, 2017). Although bottlenose dolphins are considered rare in
Puget Sound, six were observed during construction of the Seattle
Multimodal Project from 2017 through 2022 (WSDOT 2022).
Long-Beaked Common Dolphin
Long-beaked common dolphins are commonly found along the U.S. West
Coast, from Baja California, Mexico (including the Gulf of California),
northward to about central California (Carretta et al., 2020). The
Salish Sea is not considered part of their typical range (Carretta et
al., 2020), but there have been reports of long-beaked common dolphins
in inland waters. Two individual common dolphins were observed in
August and September of 2011 (Whale Museum, 2015). The first record of
a pod of long-beaked common dolphins in this area came in the summer of
2016. Beginning on June 16, 2016 long-beaked common dolphins were
observed near Victoria, B.C. Over the following weeks, a pod of 15 to
20 (including a calf) was observed in central and southern Puget Sound.
They were positively identified as long-beaked common dolphins (Orca
Network 2016). Marine mammal monitors observed two long-beaked common
dolphins during construction for the Washington State Ferries
Multimodal Project at Colman Dock in Seattle from 2017-18 construction
window (WSDOT 2022).
Pacific White-Sided Dolphin
The Pacific white-sided dolphin is found in cool temperate waters
of the North Pacific from the southern Gulf of California to Alaska.
Across the North Pacific, it appears to have a relatively narrow
distribution between 38[deg] N and 47[deg] N (Brownell et al., 1999).
In the eastern North Pacific Ocean, the Pacific white-sided dolphin is
one of the most common cetacean species, occurring primarily in shelf
and slope waters (Green et al., 1993; Barlow 2003, 2010). It is known
to occur close to shore in certain regions, including (seasonally)
southern California (Brownell et al., 1999). Results of aerial and
shipboard surveys strongly suggest seasonal north-south movements of
the species between California and Oregon/Washington; the movements
apparently are related to oceanographic influences, particularly water
temperature (Green et al., 1993; Forney and Barlow 1998; Buchanan et
al., 2001). During winter, this species is most abundant in California
slope and offshore areas; as northern waters begin to warm in the
spring, it appears to move north to slope and offshore waters off
Oregon/Washington (Green et al., 1992, 1993; Forney 1994; Forney et
al., 1995; Buchanan et al., 2001; Barlow 2003). The highest encounter
rates off Oregon and Washington have been reported during March-May in
slope and offshore
[[Page 61071]]
waters (Green et al., 1993). Large groups of Pacific white-sided
dolphins have been observed in San Juan Channel (Orca Network 2012),
north of Puget Sound, and may rarely occur in Central Puget Sound.
During construction for the Washington State Ferries Multimodal Project
at Colman Dock in Seattle, only 2 Pacific white-sided dolphins were
observed on one of the 377 days of construction from 2017 through 2021
(WSDOT 2022).
Dall's Porpoise
Dall's porpoises are endemic to temperate waters of the North
Pacific Ocean. Off the U.S. West Coast, they are commonly seen in
shelf, slope, and offshore waters (Morejohn 1979). Sighting patterns
from aerial and shipboard surveys conducted in California, Oregon, and
Washington (Green et al., 1992, 1993; Forney and Barlow 1998; Barlow
2016) suggest that north-south movement between these states occurs as
oceanographic conditions change, both on seasonal and inter-annual time
scales. Dall's porpoise are considered rare in Puget Sound. During
construction for the Washington State Ferries Multimodal Project at
Colman Dock in Seattle, only 8 Dall's porpoises were observed, with a
maximum of 5 individuals observed on a single day during the 377
construction days from 2017 through 2021 (WSDOT 2022).
Harbor Porpoise
In the eastern North Pacific Ocean, harbor porpoise are found in
coastal and inland waters from Point Barrow, along the Alaskan coast,
and down the west coast of North America to Point Conception,
California (Gaskin 1984). Harbor porpoise are known to occur year-round
in the inland trans-boundary waters of Washington and British Columbia,
Canada (Osborne et al., 1988), and along the Oregon/Washington coast
(Barlow 1988, Barlow et al., 1988, Green et al., 1992). There was a
significant decline in harbor porpoise sightings within southern Puget
Sound between the 1940s and 1990s but sightings have increased
seasonally in the last 10 years (Carretta et al., 2019). Annual winter
aerial surveys conducted by the Washington Department of Fish and
Wildlife from 1995 to 2015 revealed an increasing trend in harbor
porpoise in Washington inland waters, including the return of harbor
porpoise to Puget Sound. The data suggest that harbor porpoise were
already present in Juan de Fuca, Georgia Straits, and the San Juan
Islands from the mid-1990s to mid-2000s, and then expanded into Puget
Sound and Hood Canal from the mid-2000s to 2015, areas they had used
historically but abandoned. Changes in fishery-related entanglement was
suspected as the cause of their previous decline and more recent
recovery, including a return to Puget Sound (Evenson et al., 2016).
Seasonal surveys conducted in spring, summer, and fall 2013-2015 in
Puget Sound and Hood Canal documented substantial numbers of harbor
porpoise in Puget Sound. Observed porpoise numbers were twice as high
in spring as in fall or summer, indicating a seasonal shift in
distribution of harbor porpoise (Smultea 2015). The reasons for the
seasonal shift and for the increase in sightings is unknown. During 377
total days of construction at the Washington State Ferries Multimodal
Project at Colman Dock in Seattle from 2017 through 2021, 413 sightings
of harbor porpoises were recorded in total, with a maximum of 40
sightings on a single day.
California Sea Lion
The California sea lion is the most frequently sighted pinniped
found in Washington waters and uses haul-out sites along the outer
coast, Strait of Juan de Fuca, and in Puget Sound. Haul-out sites are
located on jetties, offshore rocks and islands, log booms, marina
docks, and navigation buoys. This species also may be frequently seen
resting in the water, rafted together in groups in Puget Sound. Only
male California sea lions migrate into Pacific Northwest waters, with
females remaining in waters near their breeding rookeries off the coast
of California and Mexico. The California sea lion was considered rare
in Washington waters prior to the 1950s. More recently, peak numbers of
3,000 to 5,000 animals move into the Salish Sea during the fall and
remain until late spring, when most return to breeding rookeries in
California and Mexico (Jeffries et al., 2000).
There are four commonly used haul-out sites near the construction
site, with the closest haul-out site located 3 km (2 mi) southwest.
During the Seattle Multimodal Project from 2017 through 2021, a total
of 3,669 sightings of California sea lions were recorded over 377 days
with a maximum of 29 observations on a single day.
Steller Sea Lion
Steller sea lions range along the North Pacific Rim from northern
Japan to California (Loughlin et al., 1984). There are two separate
stocks of Steller sea lions, the Eastern U.S. stock, which occurs east
of Cape Suckling, Alaska (144[deg] W), and the Western U.S. stock,
which occurs west of that point. Only the Western stock of Steller sea
lions, which is designated as the Western DPS of Steller sea lions, is
listed as endangered under the ESA (78 FR 66139; November 4, 2013).
Unlike the Western U.S. stock of Steller sea lions, there has been a
sustained and robust increase in abundance of the Eastern U.S. stock
throughout its breeding range. The eastern stock of Steller sea lions
has historically bred on rookeries located in Southeast Alaska, British
Columbia, Oregon, and California. However, within the last several
years a new rookery has become established on the outer Washington
coast (at the Carroll Island and Sea Lion Rock complex), with more than
100 pups born there in 2015 (Muto et al., 2020).
Steller sea lions use haul-out locations in Puget Sound, and may
occur at the same haul-outs as California sea lions, but are considered
rare visitors to Elliott Bay and the Seattle waterfront area. Few
Steller sea lions have been observed during monitoring of recent
construction projects in the area; typically fewer than 5 total
observations per year (e.g., Anchor QEA 2018, 2019). However, a total
of 112 sightings of Steller sea lions were recorded over 377 days of
monitoring from 2017 through 2021 at the Seattle Multimodal project
with a maximum of 10 sightings on a single day.
Harbor Seal
Harbor seals inhabit coastal and estuarine waters off Baja
California, north along the western coasts of the continental United
States, British Columbia, and Southeast Alaska, west through the Gulf
of Alaska and Aleutian Islands, and in the Bering Sea north to Cape
Newenham and the Pribilof Islands (Carretta et al., 2014). They haul
out on rocks, reefs, beaches, and drifting glacial ice and feed in
marine, estuarine, and occasionally fresh waters. Harbor seals
generally are non-migratory, with local movements associated with such
factors as tides, weather, season, food availability, and reproduction
(Scheffer and Slipp 1944; Fisher 1952; Bigg 1969, 1981). Within U.S.
West Coast waters, 5 stocks of harbor seals are recognized: (1)
Southern Puget Sound (south of the Tacoma Narrows Bridge); (2)
Washington Northern Inland Waters (including Puget Sound north of the
Tacoma Narrows Bridge, the San Juan Islands, and the Strait of Juan de
Fuca); (3) Hood Canal; (4) Oregon/Washington Coast; and (5) California.
Harbor seals in the project areas would be from the Washington Northern
Inland Waters stock.
[[Page 61072]]
Harbor seals are the only pinniped species that occurs year-round
and breeds in Washington waters (Jeffries et al., 2000). Pupping
seasons vary by geographic region, with pups born in coastal estuaries
(Columbia River, Willapa Bay, and Grays Harbor) from mid-April through
June; Olympic Peninsula coast from May through July; San Juan Islands
and eastern bays of Puget Sound from June through August; southern
Puget Sound from mid-July through September; and Hood Canal from August
through January (Jeffries et al., 2000). The most recent estimate for
the Washington Northern Inland Waters Stock is 16,451 based on surveys
conducted in 2019 (Carretta et al., 2023).
There is only one routinely used harbor seal haulout near Elliott
Bay and the Seattle waterfront at Blakely Rocks, approximately 10.6 km
(6.6 mi) west of the project sites. The haulout, which is estimated at
less than 100 animals, consists of intertidal rocks and reef areas
(Jefferies et al., 2000). Harbor seals are a commonly observed marine
mammal in the area of potential effects and are known to be comfortable
and seemingly curious around human activities. Observations of harbor
seals were reported during many recent construction projects along the
Seattle waterfront. During construction for the Washington State
Ferries Multimodal Project at Colman Dock in Seattle, a maximum of 32
harbor seals were observed on a single day from 2017 through 2021 for
all 377 construction days.
Northern Elephant Seal
Northern elephant seals breed and give birth in California (U.S.)
and Baja California (Mexico), primarily on offshore islands (Stewart et
al., 1994), from December to March (NOAA 2015). Males migrate to the
Gulf of Alaska and western Aleutian Islands along the continental shelf
to feed on benthic prey, while females migrate to pelagic areas in the
Gulf of Alaska and the central North Pacific Ocean to feed on pelagic
prey (Le Boeuf et al., 2000). Adults return to land between March and
August to molt, with males returning later than females. Adults return
to their feeding areas again between their spring/summer molting and
their winter breeding seasons (Carretta et al., 2015).
During all 377 construction days for the Washington State Ferries
Multimodal Project at Colman Dock in Seattle from 2017 through 2021,
only one northern elephant seal was observed. Elephant seals are
generally considered rare in Puget Sound. However, a female elephant
seal has been reported hauled-out in Mutiny Bay on Whidbey Island
periodically since 2010. She was observed alone for her first three
visits to the area, but in March 2015, she was seen with a pup. Since
then, she has produced two more pups, born in 2018 and 2020. Northern
elephant seals generally give birth in January but this individual has
repeatedly given birth in March. She typically returns to Mutiny Bay in
April and May to molt. Her pups have also repeatedly returned to haul-
out on nearby beaches (Orca Network 2020)
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al.
(2007, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). 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.
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 et al.,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
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).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section provides a discussion of the ways in which components
of the specified activity may impact marine mammals and their habitat.
The Estimated Take of Marine Mammals section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take of Marine Mammals section, and the Proposed Mitigation
section, to draw conclusions regarding the likely impacts of these
activities on the reproductive success or survivorship of individuals
and whether those impacts are reasonably expected to, or reasonably
likely to, adversely affect the
[[Page 61073]]
species or stock through effects on annual rates of recruitment or
survival.
Acoustic effects on marine mammals during the specified activities
can occur from impact pile driving and vibratory driving and removal.
The effects of underwater noise from WSDOT's proposed activities are
expected to result in only Level B harassment of marine mammals in the
action areas.
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 (ANSI 1995). 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
decibels (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 activities 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 impact pile driving, vibratory pile driving, and vibratory pile
removal. 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, 2018). Non-impulsive sounds (e.g.,
aircraft, machinery operations such as drilling or dredging, vibratory
pile driving, and active sonar systems) can be broadband, narrowband or
tonal, brief or prolonged (continuous or intermittent), and typically
do not have the high peak sound pressure with rapid rise/decay time
that impulsive sounds do (ANSI, 1995; NIOSH, 1998; NMFS, 2018). The
distinction between these two sound types is important because they
have differing potential to cause physical effects, particularly with
regard to hearing (e.g., Southall et al., 2007).
Two types of pile hammers would be used on this project: impact and
vibratory. 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. Vibratory hammers install piles by vibrating them and allowing
the weight of the hammer to push them into the sediment. Vibratory
hammers produce non-impulsive continuous sounds and 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).
Potential or likely impacts on marine mammals from WSDOT's proposed
construction include both non-acoustic and acoustic stressors. Non-
acoustic stressors include the physical presence of equipment, vessels,
and personal. However, impacts from WSDOT's proposed construction is
expected to primarily be acoustic in nature. Expected stressors from
WSDOT's proposed activities are expected to be a result of heavy
equipment operation for impact driving and vibratory driving and
removal.
Acoustic Impacts
The introduction of anthropogenic noise into the aquatic
environment from pile driving and removal is the primary means by which
marine mammals may be harassed from WSDOT's specified activity. In
general, animals exposed to natural or anthropogenic sound may
experience physical and behavioral effects, ranging in magnitude from
none to severe (Southall et al., 2007, 2021). Generally, exposure to
pile driving noise has the potential to result in auditory threshold
shifts (TS) and behavioral reactions (e.g., avoidance, temporary
cessation of foraging and vocalizing, changes in dive behavior).
Exposure to anthropogenic noise can also lead to non-observable
physiological responses such an increase in stress hormones. Additional
noise in a marine mammal's habitat can mask acoustic cues used by
marine mammals to carry out daily functions such as communication and
predator and prey detection. The effects of pile driving noise on
marine mammals are dependent on several factors, including, but not
limited to, sound type (e.g., impulsive vs. non-impulsive), the
species, age and sex class (e.g., adult male vs. mom with calf),
duration of exposure, the distance between the pile and 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 auditory effects (TSs) followed by behavioral effects
and potential impacts on habitat. No physiological effects other than
TTS are anticipated or proposed to be authorized, and therefore are not
discussed further. Discussion of physical auditory effects (TSs),
behavioral effects, and potential impacts on habitat are described
below.
NMFS defines a noise-induced TS as a change, usually an increase,
in the threshold of audibility at a specified frequency or portion of
an individual's hearing range above a previously established reference
level (NMFS, 2018). The amount of threshold shift is customarily
expressed in dB. A TS can be permanent or temporary. As described in
NMFS (2018), there are numerous factors to consider when examining the
consequence of TS, including, but not limited to, the signal temporal
pattern (e.g., impulsive or 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
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
[[Page 61074]]
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, because there are limited empirical data
measuring PTS in marine mammals (e.g., Kastak et al., 2008), 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)--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
(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 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).
Pile installation for this project includes impact pile driving and
vibratory pile driving and removal. Vibratory and impact pile driving
would not occur simultaneously but both methods could be used on the
same day. There would be pauses in the activities producing impulsive
and non-impulsive sounds each day. Given these pauses and the fact that
many marine mammals are likely moving through the project areas 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, 2021; Weilgart, 2007; Archer et al., 2010). Behavioral reactions
can vary not only among individuals but also within exposures of an
individual, depending on previous experience with a sound source,
context, and numerous other factors (Ellison et al., 2012, Southall et
al., 2021), and can vary depending on characteristics associated with
the sound source (e.g., whether it is moving or stationary, number of
sources, distance from the source). In general, pinnipeds seem more
tolerant of, or at least habituate more quickly to, potentially
disturbing underwater sound than do cetaceans, and generally seem to be
less responsive to exposure to industrial sound than most cetaceans.
For a review of the studies involving marine mammal behavioral
responses to sound, see Southall et al., 2007; Gomez et al., 2016; and
Southall et al., 2021 reviews.
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 estimates of the energetic
requirements of the affected
[[Page 61075]]
individuals and the relationship between prey availability, foraging
effort and success, and the life history stage of the animal.
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.
Elliott Bay and the Seattle area typically have elevated background
sound levels due to active commercial shipping, fishing, and ferry
operations as well as recreational use of the waterway.
Marine Mammal Habitat Effects
WSDOTs proposed construction activities could have localized
temporary impacts on marine mammal habitat, including prey, by
increasing in-water sound pressure levels and slightly decreasing water
quality. Increased noise levels associated with this project are of
short duration but may adversely affect acoustic habitat (see masking
discussion above) and adversely affect marine mammal prey within the
vicinity of the project (see discussion below). Elevated noise levels
from impact and vibratory pile driving or removal would ensonify the
project area where fish and marine mammals occur, which could affect
foraging success.
In-water pile driving and removal would also cause short term
effects on water quality, which includes increase in turbidity. WSDOT
would employ standard construction best management practices and comply
with state water quality standards during all planned activities, thus
reducing any impacts to water quality. Due to the nature and duration
of proposed effects, combined with both measure described above, the
impact from increased turbidity levels is expected to be discountable.
Pile driving and removal may temporarily increase turbidity due to
increases in suspended sediment. However, possible increases in
turbidity would temporary, restricted to the localized construction
area, and minimal. WSDOT must also comply with state water quality
standards, which would limit the extent of increased turbidity to the
immediate project area. Generally, changes in turbidity is restricted
to a localized radius of 25-feet around the pile (Everitt et al.,
1980). Cetaceans and pinnipeds are not expected to be within a radius
that would have localized increases in turbidity, but if they did
occur, they would likely be transiting through the area and could avoid
the affected area. Therefore, the effects of turbidity to on marine
mammal habitat is expected to be discountable. Lastly, pile driving and
removal would not obstruct the migration or movement of marine mammals.
In-Water Construction Effect on Potential Foraging Habitat
The area likely impacted by the project is relatively small and
provides marginal foraging habitat for marine mammals and fishes
compared to the available habitat in Puget Sound. The area is highly
influenced by anthropogenic activities. The total seafloor area
affected by pile installation and removal is a small area compared to
the vast foraging area available to marine mammals in the area. At
best, the impact area provides marginal foraging habitat for marine
mammals and fishes. Furthermore, pile driving and removal at the
project site would not obstruct long-term movements or migration of
marine mammals.
Avoidance by potential prey (i.e., fish or, in the case of
transient killer whales, other marine mammals) of the immediate area
due to the temporary loss of this foraging habitat is also possible.
The duration of fish and marine mammal avoidance of this area after
pile driving stops is unknown, but a rapid return to normal
recruitment, distribution, and behavior is anticipated. Any behavioral
avoidance by fish or marine mammals of the disturbed area would still
leave significantly large areas of fish and marine mammal foraging
habitat of similar or better quality in the nearby vicinity.
Effects on Potential Prey
Sound may affect marine mammals through impacts on the abundance,
behavior, or distribution of prey species (e.g., crustaceans,
cephalopods, fish, zooplankton, other marine mammals). Marine mammal
prey varies by species, season, and location. Here, we describe studies
regarding the effects of noise on known marine mammal prey other than
other marine mammals (which have been discussed earlier).
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 and Mann, 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; 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
[[Page 61076]]
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; Popper et al.,
2016).
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 fishes from pile driving and removal and
construction activities at the project areas would be temporary
behavioral avoidance of the area. The duration of fish avoidance of
this area after pile driving stops is unknown, but a rapid return to
normal recruitment, distribution, and behavior is anticipated.
Construction activities, in the form of increased turbidity, have
the potential to adversely affect forage fish in the project areas.
Forage fish form a significant prey base for many marine mammal species
that occur in the project areas. Increased turbidity is expected to
occur in the immediate vicinity (on the order of 10 ft (3 m) or less)
of construction activities. However, suspended sediments and
particulates are expected to dissipate quickly within a single tidal
cycle. Given the limited area affected and high tidal dilution rates
any effects on forage fish are expected to be minor or negligible.
Finally, exposure to turbid waters from construction activities is not
expected to be different from the current exposure; fish and marine
mammals in Elliott Bay are routinely exposed to substantial levels of
suspended sediment from natural and anthropogenic sources.
In summary, given the short daily duration of sound associated with
individual pile driving events and the relatively small areas being
affected, pile driving activities associated with the proposed actions
are not likely to have a permanent, adverse effect on any fish habitat,
or populations of fish species. 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. Thus, we
conclude that impacts of the specified activities are not likely to
have more than short-term adverse effects on any prey habitat or
populations of prey species. Further, any impacts to marine mammal
habitat are not expected to result in significant or long-term
consequences for individual marine mammals, or to contribute to adverse
impacts on their populations.
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
proposed for authorization through the IHA, which will inform NMFS'
consideration of ``small numbers,'' the negligible impact
determinations, and impacts on subsistence uses.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would be by Level B harassment only, in the form
behavioral reactions and TTS for individual marine mammals resulting
from exposure to noise from impact and vibratory pile driving and
removal. Based on the nature of the activity and the anticipated
effectiveness of the mitigation measures (i.e., shutdown zones at the
Level A harassment area) discussed in detail below in the Proposed
Mitigation section, Level A harassment is neither anticipated nor
proposed to be authorized.
As described previously, no serious injury or mortality is
anticipated or proposed to be authorized for this activity. Below we
describe how the proposed take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic thresholds above which NMFS believes the best
available science indicates marine mammals will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the proposed take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur PTS of some degree (equated to Level A
harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources. For in-air sounds, NMFS predicts that harbor
seals exposed above received levels of 90 dB re 20 [mu]Pa (rms) will be
behaviorally harassed, and other pinnipeds will be harassed when
exposed above 100 dB re 20 [mu]Pa (rms). Generally speaking, Level B
harassment take estimates based on these behavioral
[[Page 61077]]
harassment thresholds are expected to include any likely takes by TTS
as, in most cases, the likelihood of TTS occurs at distances from the
source less than those at which behavioral harassment is likely. TTS of
a sufficient degree can manifest as behavioral harassment, as reduced
hearing sensitivity and the potential reduced opportunities to detect
important signals (conspecific communication, predators, prey) may
result in changes in behavior patterns that would not otherwise occur.
WSDOTs proposed activity includes the use of continuous (vibratory
hammer) and impulsive (impact hammer) sources, and therefore the RMS
SPL thresholds of 120 and 160 dB re 1 [mu]Pa, respectively, are
applicable.
Level A Harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (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). WSDOTs
proposed activity includes the use of impulsive (impact hammer) and
non-impulsive (vibratory hammer) 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.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the proposed project.
Marine mammals are expected to be affected by sound generated from the
impact and vibratory pile driving components of this project.
In order to calculate distances to the Level A harassment and Level
B harassment thresholds for the methods and piles used in the proposed
project, NMFS used acoustic monitoring data from previous pile driving
at WSDOTs Bainbridge Island Ferry Terminal Project (vibratory removal
of 12-inch H-piles), Port Townsend Ferry Terminal Project (vibratory
installation and/or removal of 24 and 30-inch steel piles), Phase 2 of
Colman Dock construction for the Seattle Multimodal Project (impact
installation of 24-inch steel piles), and the Ebey Slough Bridge
Replacement Project (Vibratory installation of 72-inch steel piles).
Each of the projects listed above occurred within the Puget Sound and
provided the most suitable source levels due to similar physical
habitat characteristics, pile sizes, and pile driving or removal
methods (Table 5).
Source levels from the Bainbridge Terminal Ferry Project and the
Ebey Slough Bridge Replacement Project were used as proxies for the
vibratory installation of 78-inch steel pipe piles and the vibratory
removal of 14-inch steel H-piles for the proposed project because
source levels for identical pile sizes were unavailable. Results from
the vibratory installation of 72-inch piles at the Ebey Slough Bridge
Replacement Project showed that the unweighted RMS SPL source levels
was 170 dB re 1 [micro]Pa at 15 m, therefore it was assumed that source
levels for 78-inch piles would be 174 dB re 1 [micro]Pa at 10 m. The
source levels for 14-inch H-piles was assumed to be equivalent to the
vibratory removal of 12-inch H-piles at the Bainbridge Island Ferry
Terminal where the unweighted RMS SPL source level was 153 dB re 1
[micro]Pa at 10 m (WSDOT 2023). Bubble curtains would be employed for
impact installation of 24-inch steel piles but zero dB of effective
attenuation is assumed because a bubble curtain was used at Phase 2 of
Colman Dock construction for the Seattle Multimodal Project, thus
source levels would be the same.
Table 5--Seattle Slip 3 Vehicle Transfer Span Proxy Sound Source Levels for Pile Sizes and Driving Methods
----------------------------------------------------------------------------------------------------------------
Source Level at 10 m
Pile type and size (in) Method (dB re 1 [micro]PA) Reference
----------------------------------------------------------------------------------------------------------------
14-inch steel H-piles................ Vibratory Removal...... 153 dB rms............. WSDOT (2023).
[[Page 61078]]
24-inch steel pipe piles............. Vibratory installation 174 dB rms............. Huey (2010).
and removal.
24-inch steel pipe piles............. Impact installation.... 166 SEL, 176 dB rms, Greenbusch Group
194 dB peak. (2019).
30-inch steel sheet piles............ Vibratory installation. 174 dB rms............. Huey (2010).
78-inch steel pipe piles............. Vibratory installation. 174 dB rms............. WSDOT (2011).
----------------------------------------------------------------------------------------------------------------
Level B Harassment Zones
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
TL = B * Log10 (R1/R2)
Where:
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement
The recommended TL coefficient for most nearshore environments is
the practical spreading value of 15. This value results in an expected
propagation environment that would lie between spherical and
cylindrical spreading loss conditions, which is the most appropriate
assumption for the WSDOTs proposed activities in the absence of
specific modelling. The estimated Level B harassment zones for the
WSDOTs proposed activities are shown in Tables 6 and 7.
Level A Harassment Zones
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional user
spreadsheet tool to accompany the Technical Guidance that can be used
to relatively simply predict an isopleth distance for use in
conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically going to be
overestimates of some degree, which may result in an overestimate of
potential take by Level A harassment. However, this optional tool
offers the best way to estimate isopleth distances when more
sophisticated modeling methods are not available or practical. For
stationary sources such as pile installation and removal, the optional
User Spreadsheet tool predicts the distance at which, if a marine
mammal remained at that distance for the duration of the activity, it
would be expected to incur PTS. Inputs used in the optional User
Spreadsheet tool (e.g., number of piles per day, during and/or strikes
per pile) are presented in table 1, and the resulting estimated
isopleths and ensonified areas are reported in tables 6 and 7.
Table 6--Level A and Level B Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment zone (m)
------------------------------------------------------------- Level A
Pile size and type Pile driving method LF MF HF harassment
cetaceans cetaceans cetaceans Phocids Otarids zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-inch steel................................ Vibratory removal.............. 3.2 0.3 4.7 1.9 0.1 1,585
24-inch steel................................ Vibratory installation and 65.8 5.8 97.3 40.0 2.8 \a\ 15,410
removal.
24-inch steel................................ Impact installation............ 75.9 2.7 90.4 40.6 3.0 736
30-inch steel................................ Vibratory installation......... 50.2 4.5 74.3 30.5 2.1 \a\ 15,410
78-in steel.................................. Vibratory installation......... 50.2 4.5 74.3 30.5 2.1 \a\ 15,410
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Land is reached at a maximum of 15,410 km/9.6 miles.
Table 7--Level A and Level B Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment zone (m)
------------------------------------------------------------- Level B
Pile size and type Pile driving method LF MF HF harassment
cetaceans cetaceans cetaceans Phocids Otarids zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-inch steel................................ Vibratory removal.............. 8.0 0.07 17.4 2.8 0.007 3,247,392
24-inch steel................................ Vibratory installation and 4,524.5 5.7 6,418 1,294.6 7.07 75,844,286
removal.
24-inch steel................................ Impact installation............ 75.9 2.7 90.4 40.6 3.0 861,188
30-inch steel................................ Vibratory installation......... 1,979.2 15.9 4,336 730.6 3.5 75,844,286
78-inch steel................................ Vibratory Installation......... 1,979.2 15.9 4,336 730.6 3.5 75,844,286
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 61079]]
Marine Mammal Occurrence and Take Estimation
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information which
will inform proposed take incidental to WSDOTs pile driving activities
for the Seattle Slip 3 VTS Replacement Project. Throughout this section
the pile installation or removal will be referred to as ``pile
driving'' unless specified otherwise. From 2017 through 2021 WSDOT
monitored for marine mammals in Elliott Bay for the Seattle Multimodal
Project. During this time, marine mammal monitoring occurred for 377
days. Since the Seattle Multimodal Project occurred in Elliott Bay,
WSDOT considered this marine mammal monitoring data to be the most
comprehensive and relevant for estimating take for the Seattle Slip 3
VTS Replacement Project. Therefore, this data compiled all of these
monitoring results and calculated total sightings, average sightings
per day, and maximum sightings per day for all species of marine
mammals that were observed (table 8). WSDOT used their best
professional judgement and used this data to estimate take by
multiplying maximum sighting per day by 19, which is the maximum number
of in-water working days WSDOT estimates it would take to complete the
project in a total worst case scenario.
NMFS has carefully evaluated these methods and concludes that it is
an accurate and appropriate method for estimating take for WSDOTs
activities for this project.
Table 8--Marine Mammals Sighted at the Seattle Multimodal Project
----------------------------------------------------------------------------------------------------------------
Average Maximum
Total individuals individuals
Species individuals sighted/day sighted in one- Take requested
sighted \a\ (377 days) \a\ day \a\
----------------------------------------------------------------------------------------------------------------
Harbor seal..................................... 2,271 6.0 32 Yes
Northern elephant seal.......................... 1 0.003 1 Yes
California sea lion............................. 3,669 9.7 29 Yes
Steller sea ion................................. 112 0.3 10 Yes
Unidentified pinniped........................... 121 N/A N/A N/A
Killer whale Southern resident.................. 170 0.5 26 No
Killer whale transient.......................... 79 0.2 20 Yes
Gray whale...................................... 5 0.01 2 Yes
Humpback whale.................................. 8 0.02 1 No
Minke whale..................................... 3 0.008 1 Yes
Unidentified large whale........................ 2 N/A 1 N/A
Unidentified small whale........................ 10 N/A N/A N/A
Harbor porpoise................................. 655 1.7 72 Yes
Dall's porpoise................................. 8 0.02 5 Yes
Common bottlenose dolphin....................... 6 0.02 2 Yes
Pacific white-sided dolphin..................... 2 0.005 2 Yes
Long-beaked common dolphin...................... 0 N/A 0 Yes
Unidentified dolphin/porpoise................... 46 N/A 6 N/A
----------------------------------------------------------------------------------------------------------------
\a\ WSDOT 2022.
Gray Whale--Although gray whales are common on the southern ends of
Whidbey and Camano Islands in the Puget Sound February through May,
they are rarely sighted in the proposed construction area (Calambokidis
et al. 2024). During the Seattle multimodal project only 5 gray whales
were detected over 377 days of monitoring with a maximum of two
individuals observed on a single day (WSDOT 2022). WSDOT estimated that
up to 2 gray whales could be taken per day for the 19 days of
construction, for a total of 38 takes by Level B harassment.
Since Seattle Slip 3 VTS Replacement Project construction would
occur from August through mid-February, gray whales occurrence is
expected to be relatively low. In this context, and given that gray
whales are highly conspicuous, we have a high degree of confidence that
WSDOT can successfully implement shutdowns as necessary to avoid any
potential Level A harassment of gray whales. WSDOT must also monitor
the Orca Network and the Whale Report Alert System (WRAS) daily in
order to maintain awareness of regional whale occurrence and movements
(see Proposed Mitigation and Proposed Monitoring and Reporting sections
below). Therefore, take of gray whales by Level A harassment is not
anticipated or for authorization.
Minke Whale--Minke whales are uncommon during fall and winter
months in the Puget Sound but are rarely sighted in the proposed
construction area (Calambokidis and Baird 1994). During the Seattle
Multimodal Project only three minke whale detections occurred over 377
days of monitoring with a maximum of one detection on a single day
(WSDOT 2022). WSDOT estimated that up to one minke whale could be taken
per day for the 19 days of construction, for a total of 19 takes by
Level B harassment.
Since the Seattle Slip 3 VTS Replacement Project construction would
occur from August through mid-February, minke whale occurrence is
expected to be relatively low. In these circumstances, and given that
minke whales are highly conspicuous, we have a high degree of
confidence that WSDOT can successfully implement shutdowns as necessary
to avoid any potential Level A harassment of minke whales. WSDOT must
also monitor the Orca Network and the Whale Report Alert System (WRAS)
daily in order to maintain awareness of regional whale occurrence and
movements (see Proposed Mitigation and Proposed Monitoring and
Reporting sections below). Therefore, take of minke whales by Level A
harassment is not anticipated or for authorization.
Transient Killer Whale--Transient killer whales are common in in
the Puget Sound in all months and a total of 79 transient killer whale
detections occurred over 377 days of monitoring for the Seattle
Multimodal Project with a maximum of 20 detections in a single day
(Orca Network 2021, WSDOT 2022). WSDOT estimated that up to 20
incidents of take for transient killer whales could occur per day for
19 days of construction, for a total of 380 takes by Level B
Harassment. Transient killer
[[Page 61080]]
whales are common in the Puget Sound and are highly conspicuous.
The largest Level A harassment zone for mid-frequency cetaceans for
all construction for the Seattle Slip 3 VTS Replacement Project is less
than 6 m. It is highly unlikely that any cetacean would enter within 6
m of active pile driving, and no take by Level A harassment for any
mid-frequency cetacean is expected to occur. WSDOT must also monitor
the Orca Network and the Whale Report Alert System (WRAS) daily in
order to maintain awareness of regional whale occurrence and movements
(see Proposed Mitigation and Proposed Monitoring and Reporting sections
below). Therefore, take of transient killer whales by Level A
harassment is not anticipated or for authorization.
Bottlenose Dolphin--Bottlenose dolphins are considered to be rare
in the Puget Sound but they were detected by the Cascadia Research
Collective and reported via the Orca Network in 2017 (Cascadia Research
Collective, 2017). They were also detected on 6 occasions with a
maximum of 2 detections on a single day during the Seattle Multimodal
Project (WSDOT 2022). WSDOT estimated that up to two bottlenose
dolphins could be taken per day for the 19 days of construction, for a
total of 38 takes by Level B harassment.
The largest Level A harassment zone for mid-frequency cetaceans for
all construction of the Seattle Slip 3 VTS Replacement Project is less
than 6 m. It is highly unlikely that any cetacean would enter within 6
m of active pile driving, and no take by Level A harassment for any
mid-frequency cetacean is expected to occur. WSDOT must also monitor
the Orca Network and the Whale Report Alert System (WRAS) daily in
order to maintain awareness of regional whale occurrence and movements
(see Proposed Mitigation and Proposed Monitoring and Reporting sections
below). Therefore, take of bottlenose dolphins by Level A harassment is
not anticipated or for authorization.
Long-Beaked Common Dolphin--No confirmed detections of long-beaked
common dolphins occurred during the Seattle Multimodal Project but 6
unidentified delphinids were observed (WSDOT 2022). WSDOT assumed that
up to two of these unidentified delphinids could have been long-beaked
common dolphins. Therefore, WSDOT estimated that up to two long-beaked
common dolphins could be taken per day for the19 days of construction,
for a total of 38 takes by Level B harassment.
The largest Level A harassment zone for mid-frequency cetaceans for
all construction of the Seattle Slip 3 VTS Replacement Project is less
than 6 m. It is highly unlikely that any cetacean would enter within 6
m of active pile driving, and no take by Level A harassment for any
mid-frequency cetacean is expected to occur. WSDOT must also monitor
the Orca Network and the Whale Report Alert System (WRAS) daily in
order to maintain awareness of regional whale occurrence and movements
(see Proposed Mitigation and Proposed Monitoring and Reporting sections
below). Therefore, take of long-beaked common dolphins by Level A
harassment is not anticipated or for authorization.
Pacific White-Sided Dolphin--Pacific white-sided dolphins are rare
in the Puget Sound but have been observed in San Juan Channel (Orca
Network 2012). Two Pacific white sided dolphins were also observed
during the Seattle Multimodal Project (WSDOT 2022). WSDOT estimated
that up to two Pacific white-sided dolphins could be taken per day for
the 19 days of construction, for a total of 38 takes by Level B
harassment.
The largest Level A harassment zone for mid-frequency cetaceans for
all construction of the Seattle Slip 3 VTS Replacement Project is less
than 6 m. It is highly unlikely that any cetacean would enter within 6
m of active pile driving, and no take by Level A harassment for any
mid-frequency cetacean is expected to occur. WSDOT must also monitor
the Orca Network and the Whale Report Alert System (WRAS) daily in
order to maintain awareness of regional whale occurrence and movements
(see Proposed Mitigation and Proposed Monitoring and Reporting sections
below). Therefore, take of Pacific white-sided dolphins by Level A
harassment is not anticipated or for authorization.
Dall's Porpoise--Dall's porpoises are considered rare within the
project area. WSDOT recorded only 8 detections over 377 days of
monitoring during the Seattle Multimodal Project (WSDOT 2022). WSDOT
estimated that up to 5 Dall's porpoises could be taken per day for the
19 days of construction, for a total of 95 takes by Level B harassment.
The largest Level A harassment zone for high-frequency cetaceans
for all construction of the Seattle Slip 3 VTS Replacement Project is
less than 100 m. Due to the relatively short duration of construction
for the Seattle Slip 3 VTS Replacement Project and infrequent
detections of Dall's porpoises, WSDOT estimated that no Dall's
porpoises would be likely to enter the Level A harassment zone. Take by
Level A harassment of Dall's Porpoises is not anticipated or proposed
to be authorized.
Harbor Porpoise--From 2017 through 2022, WSDOT recorded 655
detections of harbor porpoises with a maximum of 72 detections on a
single day (WSDOT 2022). WSDOT estimated that up to 72 instances of
take for harbor porpoises could occur per day for the 19 days of
construction, for a total of 1,368 takes by Level B harassment.
The largest Level A harassment zone for high-frequency cetaceans is
under 100 m. Although harbor porpoises are relatively common in the
Puget Sound, we assume that WSDOT would be able to cease construction
if harbor porpoises entered the Level A harassment zone before
sufficient duration of exposure for PTS to occur. Take by Level A
harassment is not anticipated or proposed to be authorized.
California Sea Lion--California sea lions are relatively common
throughout the Puget Sound. During the Seattle Multimodal Project a
maximum of 29 sea lions were detected on a single day with a total of
3,669 sightings over the 377 days of monitoring (WSDOT 2022). WSDOT
estimated that 32 California sea lions would enter the Level B
harassment zone for each of the 19 days of construction, for a total of
551 takes by Level B harassment.
The largest Level A harassment zone for Otariids for all
construction of the Seattle Slip 3 VTS Replacement Project is less than
3 m. It is highly unlikely that any Otariids would enter within 3 m of
active pile driving, and no take by Level A harassment for any mid-
frequency cetacean is expected to occur. Therefore, take of California
sea lions by Level A harassment is not anticipated or for
authorization.
Steller Sea Lion--Monitoring during the Seattle Multimodal Project
recorded 112 detections of Steller sea lions over 377 days of
monitoring, which is less than one detection per day. However, a
maximum of 10 detections were recorded in a single day. Therefore,
WSDOT estimated that 10 stellar sea lions would enter the Level B
harassment zone each day for the 19 days of construction of the
project, for a total of 190 takes by Level B harassment.
The largest Level A harassment zone for Otariids for all
construction of the Seattle Slip 3 VTS Replacement Project is less than
3 m. It is highly unlikely that any Otariids would enter within 3 m of
active pile driving, and no take by Level A harassment for any mid-
frequency cetacean is expected to occur. Therefore, take of steller sea
lions by
[[Page 61081]]
Level A harassment is not anticipated or for authorization.
Harbor Seal--Harbor seals are common in the project area. During
the Seattle Multimodal Project WSDOT recorded an average of 6 harbor
seal detections per day and a maximum of 32 in a single day (WSDOT
2022). WSDOT estimated that a maximum of 32 harbor seals will enter the
Level B harassment zones for each of the 19 days of construction, for a
total of 608 takes by Level B harassment.
The largest Level A harassment zone for high-frequency phocids is
under 41 m. Although harbor seals are relatively common in the Puget
Sound, we assume that WSDOT would be able to cease construction if
harbor seals entered the Level A harassment zone before sufficient
duration of exposure for PTS to occur. Take by Level A harassment is
not anticipated or proposed to be authorized.
Northern Elephant Seal--Although northern elephant seals are rare
in the Puget Sound, 1 individual was detected during the Seattle
Multimodal Project. Since northern elephant seals are rare in the
proposed construction area, WSDOT estimated that a maximum of 1
elephant seal would enter the Level B harassment zone per day for each
of the 19 days of construction. A total of 19 takes by Level B
harassment is estimated for northern elephant seals for construction
associated with the Seattle Slip 3 VTS Replacement Project.
Similar to harbor seals, the largest harassment zone is less than
41 m for all construction activities. Given the anticipated rarity of
occurrence for elephant seals, WSDOT does not expect northern elephant
seals to enter Level A harassment zones without being detected prior to
shutdown. Construction would cease if a northern elephant seal was
observed entering Level A harassment zone. Therefore, no take by Level
A harassment of northern elephant seals is anticipated or proposed to
be authorized.
Table 9--Estimated Take of Marine Mammal by Level B Harassment for 19 Days of In-Water Construction
----------------------------------------------------------------------------------------------------------------
Total takes by
Species Maximum sightings/ Level B Percent of stock
day \a\ harassment
----------------------------------------------------------------------------------------------------------------
Phocids
----------------------------------------------------------------------------------------------------------------
Harbor seal............................................ 32 608 5.51
Northern elephant seal................................. 1 19 0.02
----------------------------------------------------------------------------------------------------------------
Otariids
----------------------------------------------------------------------------------------------------------------
California sea lion.................................... 29 551 0.24
Steller sea lion....................................... 10 190 0.23
----------------------------------------------------------------------------------------------------------------
Cetaceans
----------------------------------------------------------------------------------------------------------------
Killer whale transient................................. 20 380 110
Gray whale............................................. 2 38 0.15
Minke whale............................................ 1 19 3.7
Harbor porpoise........................................ 72 1,368 16.5
Dall's porpoise........................................ 5 95 0.37
Common bottlenose dolphin.............................. 2 38 3.0
Pacific white-sided dolphin............................ 2 38 0.13
Long-beaked common dolphin............................. 5 38 0.05
----------------------------------------------------------------------------------------------------------------
\a\ WSDOT 2022.
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, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (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, and impact on
operations.
Shutdown Zones
Prior to the start of any in-water construction, WSDOT would
establish shutdown zones for all planned activities. Shutdown zones are
pre-defined areas within which construction would be halted upon
sightings of a marine mammal or in anticipation of a marine mammal
entering the established shutdown zones. Pile-driving would not re-
commence until all marine mammals are assumed to have cleared these
established shutdown zones.
WSDOT proposed to establish shutdown zones for SRKWs and HWs at the
Level B harassment zone for the vibratory removal of 14-in piles at
1,600
[[Page 61082]]
m and at 750 m for impact driving 24-in piles (Table 6 and Table 10).
These shutdown zones are the Level B harassment zone rounded up to the
nearest 50 m for each pile size and driving method. Proposed shutdown
zones for the remaining pile-driving for SRKWs and HWs would be
established at 15,410 m, which is equivalent to the maximum Level B
harassment area before it reaches land.
The largest Level A harassment zone for the vibratory removal of
14-in piles is 3.2 m for all cetaceans and pinnipeds. However, WSDOT
proposed conservatively to implement a shutdown zone at 50 m for
removal of 14-in piles. The proposed shutdown zones for the remaining
pile-driving activities would be established at 100 m for all hearing
groups of cetaceans (except SRKWs and HWs, as discussed above) and 50 m
for all pinnipeds. The largest Level A harassment zone amongst all
hearing groups of cetaceans is would be 97.3 m for the remaining pile-
driving (Table 6). The largest Level A harassment zone amongst
pinnipeds would be 40.6 m for the remaining pile driving (Table 6).
With WSDOTs proposed shutdown zones, all incidental take would be
prevented for SRKWs and HWs and only take by Level B harassment would
occur for the remaining species of cetaceans and pinnipeds.
WSDOT would also establish shutdown zones for all other species of
marine mammals for which take has not been authorized or for which
incidental take has been authorized but the number of authorized takes
has already been met. Those zones would be equivalent to Level B
harassment zones provided for each activity in Table 6.
In addition to the shutdown zones mentioned above, WSDOT proposes
to implement shutdown measures for SRKWs and HWs. If SRKWs or HWs are
observed within or approaching established shutdown zones (see table
10), WSDOT would shut down pile driving equipment to avoid take of
these species. If a killer whale approaches a Level B harassment zone,
and it is unknown if it is a SRKW or a Transient killer whale, WSDOT
would assume it is a SRKW and implement shutdown measures. Pile driving
would only resume if the killer whale could be confirmed as a Transient
killer whale.
Table 10--Shutdown Zones for All Pile-Driving Activities for the Seattle Slip 3 VTS Replacement Project
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shutdown zones (m)
------------------------------------------------------------- SRKW and HW
Pile size and type Pile driving method LF MF HF shutdown
cetaceans cetaceans cetaceans Phocids Otarids zones (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-in steel................................. Vibratory removal.............. 50 50 50 50 50 1,600
24-in steel................................. Vibratory installation and 100 100 100 50 50 * 15,410
removal.
24-in steel................................. Impact installation............ 100 100 100 50 50 750
30-in steel................................. Vibratory installation......... 100 100 100 50 50 * 15,410
78-in steel................................. Vibratory Installation......... 100 100 100 50 50 * 15,410
--------------------------------------------------------------------------------------------------------------------------------------------------------
* 15,410 m is the maximum distance sound can travel before reaching land.
Protected Species Observers
The monitoring locations for all protected species observers (PSOs)
during all pile driving activities (described in the Proposed
Monitoring and Reporting Section) would ensure that the entirety of all
shutdown zones are visible. If environmental conditions deteriorate
such that the entirety of shutdown zones would not be visible (e.g.,
fog, heavy rain, Beaufort sea state, etc.), all pile driving would be
delayed until PSOs are confident that marine mammals in the shutdown
zones could be detected.
Monitoring for Level A and Level B Harassment
All of the harassment zones would be monitored by PSOs to the
extent practicable. Established monitoring zones would allow PSOs to
observe marine mammals and define clear monitoring protocols for areas
adjacent to shutdown zones. The monitoring zones and protocols would
enable PSOs to be aware of and communicate the presence of marine
mammals in project areas and outside of project areas to prepare for
potential cessation of pile driving activities should a marine mammal
enter a shutdown zone.
Pre-Activity Monitoring
Prior to the start of daily in-water construction activities, or
whenever a break in pile driving of 30 minutes or longer occurs, PSOs
would observe shutdown and monitoring zones for a 30 minute period. The
shutdown zone would be considered cleared when a marine mammal has not
been observed within the zone for that 30-minute period. If pile
driving is delayed or halted due to the presence of a marine mammal,
the activities would 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 and authorized take has not been
met, activities may begin. If work ceases for more than 30 minutes, the
pre-activity monitoring of the shutdown zones would 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 would 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 would 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.
Bubble Curtain
A bubble curtain would be employed during impact installation or
proofing of steel piles, unless the piles are driven in the dry, or
water is less than 3 ft (0.9 m) in depth. A noise attenuation device
would not be required during vibratory pile driving. If a bubble
curtain or
[[Page 61083]]
similar measure is used, it would distribute air bubbles around 100
percent of the piling perimeter for the full depth of the water column.
Any other attenuation measure would be required to provide 100 percent
coverage in the water column for the full depth of the pile. The lowest
bubble ring would be in contact with the mudline for the full
circumference of the ring. The weights attached to the bottom ring
would ensure 100 percent mudline contact. No parts of the ring or other
objects would prevent full mudline contact.
Based on our evaluation of the applicant's proposed measures, NMFS
has preliminarily determined that the proposed mitigation measures
provide the means of effecting the least practicable impact on the
affected species or stocks and their habitat, paying particular
attention to rookeries, mating grounds, and areas of similar
significance.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<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 activity; 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); and
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring during pile driving activities would be
conducted by PSOs meeting NMFS' standards and in a manner consistent
with the following:
<bullet> PSOs must be independent of the activity contractor (for
example, employed by a subcontractor) and have no other assigned tasks
during monitoring periods;
<bullet> At least one PSO would 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 would be designated. The lead
observer would be required to have prior experience working as a marine
mammal observer during construction.
<bullet> PSOs must be approved by NMFS prior to beginning any
activities subject to this IHA.
PSOs should 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.
During all pile driving activities, a minimum of 3 PSO will monitor
shutdown zones during pile driving activities. A total of 3 PSOs will
monitor the area for the vibratory removal 14-in steel H-piles, 2 PSOs
will monitor from the construction site and the other PSO will monitor
from Pier 69/70. For the vibratory installation and removal of 24, 30,
and 78-in steel pipe piles 8 PSOs will monitor shutdown zones. PSOs as
described above, 1 PSO will be stationed on each of the Seattle-
Bainbridge Island Ferries (2 PSOs in total on ferries), 1 PSO stationed
at Alki Beach Pier on the south end of Elliott Bay, 1 PSO stationed at
Magnolia Viewpoint on the north end of Elliott Bay, 1 PSO station at
Rolling Bay on Bainbridge Island, and another PSO stationed at Rockaway
Beach on Bainbridge Island. During impact pile driving 24-in steel pipe
piles, 2 PSOs will be stationed at the construction site and an
additional PSO will be stationed at pier 62 at the north end of the
SRKW and HW shutdown zones (Figure 3).
Monitoring would be conducted 30 minutes before, during, and 30
minutes after all in water construction activities. In addition,
observers would record all incidents of marine mammal occurrence,
regardless of distance from activity, and would document any behavioral
reactions in concert with distance from piles being driven or removed.
Pile driving activities include the time to install or remove a single
pile or series of piles, as long as the time elapsed between uses of
the pile driving equipment is no more than 30 minutes.
BILLING CODE 3510-22-P
[[Page 61084]]
[GRAPHIC] [TIFF OMITTED] TN30JY24.005
BILLING CODE 3510-22-C
Coordination With Marine Mammal Research Networks
Prior to the start of pile driving for the day, the PSOs would
contact the Orca Network to find out the location of the nearest marine
mammal sightings. Daily sightings information will be checked several
times a day. The Orca Network consists of a list of over 600 (and
growing) residents, scientists, and government agency personnel in the
United States and Canada. Sightings are called or emailed into the Orca
Network and immediately distributed to the NMFS Northwest Fisheries
Science Center, the Center for Whale Research, Cascadia Research, the
Whale Museum Hotline, and the British Columbia Sightings Network.
Sightings information collected by the Orca Network includes
detection by hydrophone. The SeaSound Remote Sensing Network is a
system of interconnected hydrophones installed in the marine
environment of Haro Strait (west side of San Juan Island) to study orca
communication, in-water noise, bottom fish ecology, and local climatic
conditions. A hydrophone at the Port Townsend Marine Science Center
measures average in-water sound levels and automatically detects
unusual sounds. These passive acoustic devices allow researchers to
hear when different marine mammals come into the region. This acoustic
network, combined with the volunteer visual sighting network allows
researchers to document presence and location of various marine mammal
species.
WSDOT also participates in the Whale Report Alert System (WRAS/
WhaleReport Alert System--Ocean Wise). In October 2018, the Ocean Wise
Sightings Network (formerly the B.C. Cetacean Sightings Network)
launched an alert system that broadcasts details of whale presence to
large commercial vessels. Information on whale presence is obtained
from real-time observations reported to the Ocean Wise Sightings
Network via the WhaleReport app. The alerts inform shipmasters and
pilots of cetacean occurrence in their vicinity. This awareness better
enables vessels to undertake adaptive mitigation measures, such as
slowing down or altering course in the presence of cetaceans, to reduce
the risk of collision and disturbance.
All WSDOT ferry vessel crews have been trained in the use of WRAS,
and input new sightings of cetaceans so data would be available to
other vessels and to PSOs on the project. The lead PSO will check the
WRAS sightings regularly during the day to be aware of cetaceans
approaching the shutdown zones.
With this level of coordination in the region of activity, WSDOT
would be able to get additional real-time information on the presence
or absence of cetaceans prior to start of in-water construction each
day.
[[Page 61085]]
Reporting
A draft marine mammal monitoring report would be submitted to NMFS
within 90 days after the completion of pile driving activities, or 60
days prior to a requested date of issuance of any future IHAs for the
project, or other projects at the same location, whichever comes first.
The marine mammal report would include an overall description of work
completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report would 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) number of
strikes for each pile (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.
For each observation of a marine mammal, the following would 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 ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
reports would constitute the final reports. If comments are received, a
final report addressing NMFS' comments would be required to be
submitted within 30 days after receipt of comments. All PSO datasheets
and/or raw sighting data would 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, WSDOT would report the
incident to the Office of Protected Resources (OPR)
(<a href="/cdn-cgi/l/email-protection#267674086f7276086b49484f5249544f484174435649545255664849474708414950"><span class="__cf_email__" data-cfemail="376765197e6367197a58595e4358455e595065524758454344775958565619505841">[email protected]</span></a>), NMFS and to the West Coast Region
(WCR) regional stranding coordinator as soon as feasible. If the death
or injury was clearly caused by the specified activity, WSDOT would
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 IHAs. WSDOT would not resume their activities until notified by
NMFS.
The report would include the following information:
1. Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
2. Species identification (if known) or description of the
animal(s) involved;
3. Condition of the animal(s) (including carcass condition if the
animal is dead);
4. Observed behaviors of the animal(s), if alive;
5. If available, photographs or video footage of the animal(s); and
6. 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 of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating this information relative to population status. Consistent
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338,
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, ongoing
sources of human-caused mortality, or ambient noise levels).
Pile driving and removal activities associated with this project
have the potential to disturb or displace marine mammals. The
activities for this project may result in incidental take, in the form
of Level B harassment, from underwater sound generated from pile
driving or removal. Potential takes could occur if marine mammals are
present in the ensonified zone when pile driving activities are
underway.
The takes from Level B harassment would be due to potential
behavioral disturbance and TTS. No serious injury or mortality is
anticipated given the nature of the activities 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).
To avoid repetition, the discussion of our analysis applies to all
the species listed in Table 2, given that the anticipated effects of
this activity on these different marine mammal stocks are expected to
be similar in nature. Where there are special circumstances for a
species or stock (e.g., gray whales), they are included as a separate
subsection below.
NMFS has identified key factors which may be employed to assess the
level of analysis necessary to conclude whether potential impacts
associated with a specified activity should be considered negligible.
These include (but are not limited to) the type and magnitude of
taking, the amount and importance of the available habitat for
[[Page 61086]]
the species or stock that is affected, the duration of the anticipated
effect to the species or stock, and the status of the species or stock.
The following factors support negligible impact determinations for all
affected stocks.
No take by Level A harassment is anticipated or proposed to be
authorized incidental to the Seattle Slip 3 VTS Replacement Project.
However, take by Level B harassment is expected and proposed to be
authorized for 12 marine mammal species. Effects on individuals that
are taken by Level B harassment, on the basis of reports in the
literature as well as monitoring from other similar activities, will
likely be limited to reactions such as area avoidance, increased
swimming speeds, increased surfacing time, or decreased foraging (if
such activity were occurring) (e.g., Thorson and Reyff 2006 and NMFS
2018). Individual marine mammals would most likely move away from sound
sources and temporarily avoid the ensonified area while pile driving is
occurring. If the sound produced from the construction activities is
sufficiently disturbing, marine mammals are likely to simply avoid the
area while activities are occurring, particularly as the project is
located on a busy waterfront with high amounts of vessel traffic. We
expect that any avoidance of the project areas by marine mammals would
be temporary in nature and that any marine mammals that avoid the
project areas during construction would not be permanently displaced.
Short-term avoidance of the project areas and energetic impacts of
interrupted foraging or other important behaviors is unlikely to affect
the reproduction or survival of individual marine mammals, and the
effects of behavioral disturbance on individuals is not likely to
accrue in a manner that would affect the rates of recruitment or
survival of any affected stock.
The projects are 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.
Aside from the biologically important area (BIA) for gray whales
described below, there are no known areas of importance for other
marine mammals, such as feeding or pupping areas, in the project area.
For all species and stocks, take would occur within a limited,
relatively confined area (Elliott Bay within central Puget Sound) of
the stocks' ranges. Given the availability of suitable habitat nearby,
any displacement of marine mammals from the project areas is not
expected to affect marine mammals' fitness, survival, and reproduction
due to the limited geographic area that will be affected in comparison
to the much larger habitat for marine mammals in Puget Sound. Level B
harassment will be reduced to the level of least practicable adverse
impact to the marine mammal species or stocks and their habitat through
use of mitigation measures described herein. Some individual marine
mammals in the project areas may be present and be subject to repeated
exposure to sound from pile driving on multiple days. However, these
individuals would likely return to normal behavior during gaps in pile
driving activity. The Seattle waterfront is a busy area and monitoring
reports from previous in water pile driving activities indicate that
marine mammals remain in Elliott Bay and the central Puget Sound area
throughout pile driving activities. Therefore, any behavioral effects
of repeated or long duration exposures are not expected to negatively
affect survival or reproductive success of any individuals. Thus, even
repeated Level B harassment of some small subset of an overall stock is
unlikely to result in any effects on rates of reproduction and survival
of the stock.
Gray Whales
The Puget Sound is part of a BIA for gray whales as they migrate
between the Arctic and Mexico (Calambokidis et al., 2024). Although the
proposed project area is located within the Puget Sound, the gray whale
BIA does not overlap with the ensonified zones and gray whales
typically remain further north around Whidbey and Camano Islands
(Calambokidis et al., 2018). Gray whales are also rarely seen in the
project area. This suggests that impacts from the project would have
minimal to no impact on the migration of gray whales in the BIA, and
would therefore not affect reproduction or survival.
There was a UME for gray whales from 2018 through 2023 (see the
Description of Marine Mammals in the Area of Specified Activities
section of this notice). However, we do not expect takes proposed to be
authorized for this project to have any additional affects to
reproduction or survival. As mentioned previously, no take by Level A
harassment, serious injury or mortality is expected. Takes proposed to
be authorize by Level B harassment of gray whales would primarily be in
the form of behavioral disturbance. The results from necropsies showed
evidence that gray whale nutritional condition was poor during the UME.
The area that would be temporarily impacted from construction does not
overlap with the gray whale feeding BIA in the northern Puget Sound.
Therefore, the construction associated with the Seattle Slip 3 VTS
Replacement Project is unlikely to disrupt any critical behaviors
(e.g., feeding) or have any effect on reproduction or survival of gray
whales.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect any of the species
or stocks through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> Level A harassment is not anticipated or proposed to be
authorized for all 12 marine mammal species;
<bullet> Level B harassment would be in the form of behavioral
disturbance, primarily resulting in avoidance of the project areas
around where impact or vibratory pile driving is occurring, and some
low-level TTS that may limit the detection of acoustic cues for
relatively brief amounts of time in relatively confined footprint of
the activities;
<bullet> Nearby areas of similar habitat value within Puget Sound
are available for marine mammals that may temporarily vacate the
project areas during construction activities for both projects;
<bullet> Effects on species that serve as prey for marine mammals
from the activities are expected to be short-term and, therefore, any
associated impacts on marine mammal feeding are not expected to result
in significant or long-term consequences for individuals, or to accrue
to adverse impacts on their populations from either project;
<bullet> The number of anticipated takes by Level B harassment is
relatively low for all stocks for both projects;
<bullet> The ensonifed areas from the project is very small
relative to the overall habitat ranges of all species and stocks, and
will not adversely affect ESA-designated critical habitat, or cause
more than minor impacts in any BIAs or any other areas of known
biological importance;
[[Page 61087]]
<bullet> The lack of anticipated significant or long-term negative
effects to marine mammal habitat from the project;
<bullet> The efficacy of the mitigation measures in reducing the
effects of the specified activities on all species and stocks for the
project; and
<bullet> Monitoring reports from similar work in Puget Sound that
have documented little to no effect on individuals of the same species
that could be impacted by the specified activities from the project.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, NMFS preliminarily finds that the total marine
mammal take from the proposed activity will have a negligible impact on
all affected marine mammal species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the 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.
For all species and stocks other than killer whales from the West
Coast Transient stock, the proposed take is below one-third of the
stock abundance. The proposed take of Transient killer whales as a
proportion of the stock abundance is greater than one-third, if all
takes are assumed to occur for different individuals. The project area
represents a small portion of the stock's range from Alaska to
California (Muto et al., 2019). Sighting reports from the Orca Network
support that it is reasonable to suspect that the same individual
Transient Killer whales would be present within the ensonified project
area during the relatively short duration (19 days) of proposed
activities. Since the construction area represents a small portion of
Transient killer whales range and construction would occur over a short
period, it is more likely that there will be multiple takes of the same
individuals during proposed activities.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds that small
numbers of marine mammals would be taken relative to the population
size of the affected species or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
Endangered Species Act
Section 7(a)(2) of the ESA 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 WSDOT for conducting the Seattle Slip 3 VTS Replacement
Project at Colman Dock in Seattle, Washington, 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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</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
Seattle Slip 3 VTS Replacement Project. We also request 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 activities as described in the Description of Proposed
Activity section of this notice is planned or (2) the activities as
described in the Description of Proposed Activity 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); and
<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);
and
(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.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2024-16753 Filed 7-29-24; 8:45 am]
BILLING CODE 3510-22-P
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