Notice2024-30455
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to U.S. Coast Guard Fast Response Cutter Homeporting in Seward and Sitka, Alaska
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
December 20, 2024
Effective
September 1, 2026
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued two incidental harassment authorizations (IHAs) to the United States Coast Guard (USCG) to incidentally harass marine mammals during construction activities associated with fast response cutter (FRC) homeporting in Seward and Sitka, Alaska.
Full Text
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<title>Federal Register, Volume 89 Issue 245 (Friday, December 20, 2024)</title>
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[Federal Register Volume 89, Number 245 (Friday, December 20, 2024)]
[Notices]
[Pages 104090-104105]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-30455]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE184]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to U.S. Coast Guard Fast Response
Cutter Homeporting in Seward and Sitka, Alaska
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of incidental harassment authorizations.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued two incidental harassment authorizations (IHAs) to
the United States Coast Guard (USCG) to incidentally harass marine
mammals during construction activities associated with fast response
cutter (FRC) homeporting in Seward and Sitka, Alaska.
DATES: These authorizations are effective from September 1, 2026,
through August 31, 2027, and from March 1, 2027, through February 29,
2028.
ADDRESSES: 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.
FOR FURTHER INFORMATION CONTACT: Alyssa Clevenstine, 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 monitoring and
reporting of the takings. The definitions of all applicable MMPA
statutory terms cited above are included in the relevant sections
below.
Summary of Request
On January 19, 2024, NMFS received a request from the USCG for two
IHAs to take marine mammals incidental to pile driving (installation
and removal) associated with construction of two FRC homeporting docks
in Seward and Sitka, Alaska. Following NMFS' review of the application,
the USCG submitted revised versions on April 3, 2024, June 6, 2024, and
June 11, 2024. The application was deemed adequate and complete on June
11, 2024. The USCG's request is for take of 11 species (18 stocks) of
marine mammals by Level B harassment and, for a subset of 5 of these
species, Level A harassment. Neither the USCG nor NMFS expect serious
injury or mortality to result from this activity and, therefore, IHAs
are appropriate.
Description of the Specified Activity
Overview
The USCG plans to construct shore-side facilities and associated
infrastructure at Moorings Seward to homeport one FRC located in the
Seward Marine Industrial Center (SMIC) boat basin, and demolishing and
constructing shore-side facilities at Moorings Sitka in Sitka Harbor to
support a second FRC. The shore-side facilities and associated
infrastructure for Moorings Seward will be constructed parallel to the
existing SMIC dock. Construction of a new floating dock at Moorings
Sitka will be attached to the existing pier. The projects are needed to
provide adequate vessel berthing capability to support modern USCG
cutters and ultimately, readiness as part of the USCG's overall
mission. The USCG plans to use a variety of methods, including impact,
down-the-hole (DTH), and vibratory pile driving, to install and remove
piles, including concrete, steel, plastic, and timber piles. These
methods of pile driving will introduce underwater sounds that may
result in take, by Level A and Level B harassment, of marine mammals.
Pile removal may occur by vibratory, cutting, or clipping methods.
Cutting and clipping are not anticipated to have the potential to
result in incidental take of marine mammals because they are either
above water, do not last for sufficient duration to present the
reasonable potential for disruption of behavioral patterns, do not
produce sound levels with likely potential to result in marine mammal
harassment, or some combination of the above.
Each IHA will be effective for 1 year from the date of issuance.
Pile extraction and installation activities at Moorings Seward will
occur for a total of 22 non-consecutive days, of which pile removal is
anticipated to take 2 days and pile installation is anticipated to take
a maximum of 20 days (15 days to complete installation plus 5
additional days to account for potential weather-related delays). Pile
removal and installation activities at Moorings Sitka will occur for a
total of 117 non-consecutive days, of which pile removal is anticipated
to take 3 days and pile installation is anticipated to take a maximum
of 114 days (89 days to complete installation plus 25 additional days
to account for potential weather-related delays).
A detailed description of the planned construction project is
provided in the Federal Register notice for the proposed IHA (89 FR
60359, July 25, 2024). Since that time, no changes have been made to
the planned activities. Therefore, a detailed description is not
provided here. Please refer to that Federal Register notice for the
description of the specific activity.
[[Page 104091]]
Planned mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Mitigation and
Monitoring and Reporting sections).
Comments and Responses
A notice of NMFS' proposal to issue two IHAs to the USCG was
published in the Federal Register on July 25, 2024 (89 FR 60359). That
notice described, in detail, the USCG's activity, the marine mammal
species that may be affected by the activity, and the anticipated
effects on marine mammals. In that notice, we requested public input on
the request for authorizations described therein, our analyses, the
proposed authorizations, and any other aspect of the notice of proposed
IHAs, and requested that interested persons submit relevant
information, suggestions, and comments.
During the 30-day public comment period, NMFS did not receive any
substantive comments on the proposed IHAs.
Changes From the Proposed IHA to Final IHA
There were two changes from the proposed IHAs: the dates for
planned work at both locations and the estimated take at both locations
(four species (four stocks) at Moorings Seward, four species (five
stocks) at Moorings Sitka). The former was made upon the applicant's
request and resulted in changes to the dates planned for in-water work
at Moorings Seward to occur from March 1, 2027, through February 29,
2028, and at Moorings Sitka to occur from September 1, 2026, through
August 31, 2027.
Changes to estimated take were made as a result of NMFS'
incorporation of the 2024 Updated Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Updated
Technical Guidance; NMFS, 2024). On May 3, 2024, NMFS published and
solicited public comment on its draft Updated Technical Guidance (89 FR
36762), which included updated thresholds and weighting functions to
inform auditory injury (AUD INJ) estimates. The 2024 Updated Technical
Guidance was finalized on October 24, 2024 (89 FR 84872) and represents
the best available science, replacing the 2018 Technical Guidance
(NMFS, 2018). To best ensure we have considered an appropriate estimate
of take by Level A harassment, in consideration of the best available
science, we conducted basic comparative calculations using the 2024
Updated Technical Guidance for the purposes of understanding the number
of takes by Level A harassment (AUD INJ) that would be predicted. The
relevant updated thresholds and weighting functions may be found in the
executive summary of the 2024 Updated Technical Guidance, on pages 3
through 6. We also considered whether modifications to mitigation zones
would be appropriate in light of the 2024 Updated Technical Guidance.
Based on the outcome of these comparisons using the 2024 Updated
Technical Guidance, updated take numbers are presented in tables 11 and
12 of this notice (see Estimated Take of Marine Mammals section). For
the purposes of the negligible impact analyses for a given species or
stock, the higher of any two Level A harassment estimates is
considered. No updates were made to planned mitigation zones in
consideration of the 2024 Updated Technical Guidance (see Mitigation
section).
The use of the 2024 Updated Technical Guidance resulted in an
increase in the size of the Level A harassment isopleth(s) for certain
species groups, which therefore increased take by Level A harassment
for the following species, for which we relied on density data and the
estimated ensonified areas: harbor porpoise at Moorings Seward and
Dall's porpoise at Moorings Sitka. It also resulted in an increase in
the size of the Level A harassment isopleth and resulting take by Level
A harassment of Steller sea lions at both locations, for which we
relied on occurrence data. Take by Level A harassment of low-frequency
cetaceans was not expected under the 2018 Technical Guidance and is not
expected under the 2024 Updated Technical Guidance; the Level A
harassment isopleth during DTH activities for this group decreased.
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 lists all species or stocks for which take is expected and
authorized for the specified activities at Seward and Sitka, 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 authorized here, PBR and annual serious
injury and mortality from anthropogenic sources are included here as
gross indicators of the status of the species or stocks and other
threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
either NMFS' U.S. Alaska SARs or U.S. Pacific SARs. All values
presented in table 1 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>.
[[Page 104092]]
Table 1--Marine Mammal Species \1\ 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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Family Eschrichtiidae
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Gray Whale.......................... Eschrichtius robustus.. Eastern North Pacific.. -, -, N 26,960 (0.05, 25,849, 801 131
2016).
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Family Balaenopteridae (rorquals)
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Fin Whale........................... Balaenoptera physalus.. Northeast Pacific...... E, D, Y UND (UND, UND, 2013).. UND 0.6
Humpback Whale...................... Megaptera novaeangliae. Hawai[revaps]i......... -, -, N 11,278 (0.56, 7,265, 127 27.09
2020).
Humpback Whale...................... Megaptera novaeangliae. Mexico-North Pacific... T, D, Y N/A (N/A, N/A, 2006).. UND 0.57
Minke Whale \5\..................... Balaenoptera Alaska................. -, -, N N/A (N/A, N/A, N/A)... UND 0
acutorostrata.
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Family Delphinidae
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Killer Whale........................ Orcinus orca........... Eastern North Pacific -, -, N 1,920 (N/A, 1,920, 19 1.3
Alaska Resident. 2019).
Killer Whale........................ Orcinus orca........... Eastern North Pacific -, -, N 587 (N/A, 587, 2012).. 5.9 0.8
Gulf of Alaska,
Aleutian Islands and
Bering Sea Transient.
Killer Whale........................ Orcinus orca........... Eastern Northern -, -, N 302 (N/A, 302, 2018).. 2.2 0.2
Pacific Northern
Resident.
Killer Whale........................ Orcinus orca........... West Coast Transient... -, -, N 349 (N/A, 349, 2018).. 3.5 0.4
Pacific White-Sided Dolphin......... Lagenorhynchus North Pacific.......... -, -, N 26,880 (N/A, N/A, UND 0
obliquidens. 1990).
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Family Phocoenidae (porpoises)
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Dall's Porpoise \6\................. Phocoenoides dalli..... Alaska................. -, -, N UND (UND, UND, 2015).. UND 37
Harbor Porpoise..................... Phocoena phocoena...... Gulf of Alaska......... -, -, Y 31,046 (0.21, N/A, UND 72
1998).
Harbor Porpoise \7\................. Phocoena phocoena...... Yakutat/Southeast -, -, N N/A (N/A, N/A, 1997).. UND 22.2
Alaska Offshore Waters.
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Family Otariidae (eared seals and sea lions)
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Northern Fur Seal................... Callorhinus ursinus.... Eastern Pacific........ -, D, Y 626,618 (0.2, 530, 11,403 373
376, 2019).
Steller Sea Lion.................... Eumetopias jubatus..... Western................ E, D, Y 49,837 (N/A, 49,837, 299 267
2022).
Steller Sea Lion.................... Eumetopias jubatus..... Eastern................ -, -, N 36,308 (N/A, 36,308, 2,178 93.2
2022).
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Family Phocidae (earless seals)
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Harbor Seal......................... Phoca vitulina......... Prince William Sound... -, -, N 44,756 (N/A, 41,776, 1,253 413
2015).
Harbor Seal......................... Phoca vitulina......... Sitka/Chatham Strait... -, -, N 13,289 (N/A, 11,883, 356 77
2015).
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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>).
\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 SARs 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, vessel 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\ No population estimates have been made for the number of minke whales in the entire North Pacific. Some information is available on the numbers of
minke whales in some areas of Alaska, but in the 2009, 2013, and 2015 offshore surveys, so few minke whales were seen during the surveys that a
population estimate for the species in this area could not be determined (Rone et al., 2017). Therefore, this information is N/A (not available).
\6\ Previous abundance estimates covering the entire stock's range are no longer considered reliable and the current estimates presented in the SARs and
reported here only cover a portion of the stock's range. Therefore, the calculated Nmin and PBR is based on the 2015 survey of only a small portion of
the stock's range. PBR is considered to be biased low since it is based on the whole stock whereas the estimate of mortality and serious injury is for
the entire stock's range.
\7\ Abundance estimates assumed that detection probability on the trackline was perfect; work is underway on a corrected estimate. Additionally,
preliminary data results based on environmental DNA analysis show genetic differentiation between harbor porpoise in the northern and southern regions
on the inland waters of southeast Alaska. Geographic delineation is not yet known. Data to evaluate population structure for harbor porpoise in
Southeast Alaska have been collected and are currently being analyzed. Should the analysis identify different population structure than is currently
reflected in the Alaska SARs, NMFS will consider how to best revise stock designations in the future.
As indicated above, all 11 species (with 18 managed stocks) in
table 1 temporally and spatially co-occur with the activities to the
degree that take is reasonably likely to occur at either location. All
species that could potentially occur in the project areas are included
in section 4 and tables 3-1 and 3-2 of the USCG's IHA application.
A detailed description of the species likely to be affected by the
USCG project, including brief introductions to the species and relevant
stocks as well as available information regarding population trends and
threats, and information regarding local occurrence, were provided in
the Federal Register notice for the proposed IHA (89 FR 60359, July 25,
2024); since that time, we are not aware of any changes in the status
of these species and stocks; therefore, detailed descriptions are not
provided here. Please refer to that Federal Register notice for these
descriptions. Please also refer to NMFS' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) for generalized species accounts.
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
[[Page 104093]]
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 auditory or auditory
evoked potential techniques) or estimated hearing ranges (behavioral
response data, anatomical modeling, etc.). NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups and,
in 2024, updated the hearing group terminology (NMFS, 2024).
Generalized hearing ranges were chosen based on the approximately 65-
decibel (dB) threshold from the composite audiograms, previous analysis
in NMFS (2018), and/or data from Southall et al. (2007) and Southall et
al. (2019). Marine mammal hearing groups and their associated hearing
ranges based on the Updated Technical Guidance are provided in table 2.
Table 2--Marine Mammal Hearing Groups
[NMFS, 2024]
------------------------------------------------------------------------
Hearing group [supcaret] Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 36 ** kHz.
whales).
High-frequency (HF) cetaceans (dolphins, 150 Hz to 160 kHz.
toothed whales, beaked whales, bottlenose
whales).
Very High-frequency (VHF) cetaceans (true 200 Hz to 165 kHz.
porpoises, Kogia, river dolphins,
cephalorhynchid, Lagenorhynchus cruciger
& L. australis).
Phocid pinnipeds (PW) (underwater) (true 40 Hz to 90 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 68 kHz.
lions and fur seals).
------------------------------------------------------------------------
[supcaret] Southall et al. (2019) indicates that as more data become
available there may be separate hearing group designations for Very
Low-Frequency cetaceans (blue, fin, right, and bowhead whales) and Mid-
Frequency cetaceans (sperm, killer, and beaked whales). However, at
this point, all baleen whales are part of the LF cetacean hearing
group, and sperm, killer, and beaked whales are part of the HF
cetacean hearing group. Additionally, recent data indicates that as
more data become available for Monachinae seals, separate hearing
group designations may be appropriate for the two phocid subfamilies
(Ruscher et al., 2021; Sills et al., 2021).
* 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 the ~65-dB threshold from composite
audiogram, previous analysis in NMFS (2018), and/or data from Southall
et al. (2007) and Southall et al. (2019). Additionally, animals are
able to detect very loud sounds above and below that ``generalized''
hearing range.
** NMFS is aware that the National Marine Mammal Foundation successfully
collected preliminary hearing data on two minke whales during their
third field season (2023) in Norway. These data have implications for
not only the generalized hearing range for low-frequency cetaceans but
also on their weighting function. However, at this time, no official
results have been published. Furthermore, a fourth field season (2024)
has concluded, where more data were collected. Thus, it is premature
for us to propose any changes to our current Updated Technical
Guidance. However, mysticete hearing data is identified as a special
circumstance that could merit reevaluating the acoustic criteria in
this document. Therefore, we anticipate that once the data from both
field seasons are published, it will likely necessitate updating this
document (i.e., likely after the data gathered in the summer 2024
field season and associated analysis are published).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2024) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from the USCG's construction
activities have the potential to result in harassment of marine mammals
in the vicinity of the project areas. The notice of proposed IHA (89 FR
60359, July 25, 2024) included a discussion of the effects of
anthropogenic noise on marine mammals and the potential effects of
underwater noise from the USCG's construction activities on marine
mammals and their habitat. That information and analysis is referenced
in this final IHA determination and is not repeated here; please refer
to the notice of proposed IHA (89 FR 60359, July 25, 2024).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
authorized through the IHAs, which informed 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 primarily be by Level B harassment, as use
of the acoustic sources (i.e., vibratory and impact pile driving, DTH)
has the potential to result in disruption of behavioral patterns for
individual marine mammals. There is also some potential for AUD INJ
(Level A harassment) to result, primarily for high-frequency species
and phocids, because predicted AUD INJ zones are large and these
species could enter the Level A harassment zones and remain undetected
for a sufficient duration to incur AUD INJ due to their small size and
inconspicuous nature. Although AUD INJ could occur for low-frequency
species due to large predicted AUD INJ zones associated with DTH, due
to their large size, conspicuous nature, and planned mitigation (i.e.,
large shutdown zones, boat-based protected species observers (PSOs)),
it is assumed that all low-frequency species would be visually detected
and, therefore, taking by Level A harassment would be eliminated. The
planned mitigation and monitoring measures are expected to minimize the
severity of the taking to the extent practicable.
As described previously, no serious injury or mortality is
anticipated or authorized for this activity. Below we describe how the
authorized 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 authorized take estimates.
[[Page 104094]]
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 AUD INJ (which includes, but is not
limited to, permanent threshold shift (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; Southall et al., 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. Generally speaking, Level B
harassment take estimates based on these behavioral harassment
thresholds are expected to include any likely takes by temporary
threshold shift (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.
The USCG's planned activity includes the use of continuous
(vibratory and DTH) and impulsive (impact driving and DTH) sources, and
therefore the 120 and 160 dB re 1 [mu]Pa (RMS) thresholds,
respectively, are applicable.
Level A harassment--NMFS' 2024 Updated Technical Guidance (NMFS,
2024) identifies dual criteria to assess AUD INJ (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). The USCG's planned activity includes the
use of impulsive (impact driving and DTH) and non-impulsive (vibratory
and DTH) sources.
These criteria are provided in table 3 below. The references,
analysis, and methodology used in the development of the thresholds are
described in the 2024 Updated Technical Guidance, which may be accessed
at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance-other-acoustic-tools</a>.
Table 3--Summary of Marine Mammal AUD INJ Onset Criteria
[NMFS, 2024]
----------------------------------------------------------------------------------------------------------------
AUD INJ onset criteria * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: L0-pk,flat: 222 Cell 2: LLF,24h: 197 dB.
dB; LLF,24h: 183 dB.
High-Frequency (HF) Cetaceans.......... Cell 3: L0-pk,flat: 230 Cell 4: LHF,24h: 201 dB.
dB; LHF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans.... Cell 5: L0-pk,flat: 202 Cell 6: LVHF,24h: 181 dB.
dB; LVHF,24h: 159 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: L0-pk,flat: 223 Cell 8: LPW,24h: 195 dB.
dB; LPW,24h: 183 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: L,0-pk,flat: 230 Cell 10: LOW,24h: 199 dB.
dB; LOW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric criteria for impulsive sounds: Use whichever criteria results in the larger isopleth for
calculating AUD INJ onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure
level criteria associated with impulsive sounds, the PK SPL criteria are recommended for consideration for non-
impulsive sources.
Note: Peak sound pressure level (L0-pk) has a reference value of 1 [mu]Pa (underwater) and 20 [mu]Pa (in air),
and weighted cumulative sound exposure level (L) has a reference value of 1[mu]Pa\2\s (underwater) and 20
[mu]Pa\2\s (in air). In this table, criteria are abbreviated to be more reflective of International
Organization for Standardization standards (ISO, 2017; ISO, 2020). The subscript ``flat'' is being included to
indicate peak sound pressure are flat weighted or unweighted within the generalized hearing range of marine
mammals underwater (i.e., 7 Hz to 165 kHz) or in air (i.e., 42 Hz to 52 kHz). The subscript associated with
cumulative sound exposure level criteria indicates the designated marine mammal auditory weighting function
(LF, HF, and VHF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours.
The weighted cumulative sound exposure level criteria 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 criteria 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 (TL)
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the project. Marine
mammals are expected to be affected via sound generated by the primary
components of the project (i.e., impact pile driving, vibratory pile
driving, vibratory pile removal, and DTH).
In order to calculate distances to the Level A harassment and Level
B harassment thresholds for the methods and piles planned for this
project, NMFS used acoustic monitoring data from other locations to
develop source levels for the various pile types, sizes, and methods
(tables 4-7).
NMFS recommends treating DTH systems as both impulsive and
continuous, non-impulsive sound source types simultaneously. Thus,
impulsive thresholds are used to evaluate Level A harassment, and
continuous thresholds are used to evaluate Level B harassment. With
regards to DTH mono-hammers, NMFS
[[Page 104095]]
recommends proxy levels for Level A harassment based on available data
regarding DTH systems of similar sized piles and holes (Denes et al.,
2019; Guan and Miner, 2020; Heyvaert and Reyff, 2021; Reyff, 2020;
Reyff and Heyvaert, 2019).
Table 4--Observed Non-Impulsive Sound Levels and Durations for In-Water Activities Likely To Occur at Moorings
Seward
----------------------------------------------------------------------------------------------------------------
Average
RMS SPL (dB re duration Piles per
In-water activity Pile size and type 1 [mu]Pa) at per pile day
10 m (seconds)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Extraction \a\............. 14-inch steel guide pile.... 160 1,800 5
Vibratory Pile Settling \a\............... 30-inch concrete guide pile. 163 600 2
Rock socket drill \b\ (non-impulsive 30-inch concrete guide pile. 174 \c\ 10,800 2
component).
----------------------------------------------------------------------------------------------------------------
Note: Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters.
\a\ NMFS, 2024.
\b\ NMFS, 2022.
\c\ Rock socket drilling is a DTH activity with multiple strikes per second. DTH activities produce sounds that
simultaneously contain both non-impulsive and impulsive components.
Table 5--Observed Impulsive Sound Levels and Durations for Pile Installation Activities Likely To Occur at Moorings Seward
--------------------------------------------------------------------------------------------------------------------------------------------------------
SELsingle-strike
Peak (dB re 1 RMS (dB re 1 (dB re 1 Strikes per Maximum Piles per
Installation method Pile size and type [mu]Pa) at 10 [mu]Pa) at 10 [mu]Pa\2\s) at day strikes day
m m 10 m per pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rock socket drill \a\.................. 30-inch concrete guide 194 174 164 \c\ 216,000 108,000 2
pile.
Impact hammer proofing \b\............. 30-inch concrete guide 198 186 173 10 5 2
pile.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters.
\a\ NMFS, 2022.
\b\ NMFS, 2024.
\c\ Rock socket drilling is a DTH activity with multiple strikes per second. DTH activities produce sounds that simultaneously contain both non-
impulsive and impulsive components.
Table 6--Observed Non-Impulsive Sound Levels and Durations for In-Water Activities Likely To Occur at Moorings
Sitka
----------------------------------------------------------------------------------------------------------------
Average
RMS SPL (dB re duration Piles per
In-water activity Pile size and type 1 [mu]Pa) at per pile day
10 m (seconds)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Extraction \a\............. 12-inch timber piles........ 162 1,800 5
Vibratory Pile Settling \b\............... 30-inch concrete guide and 163 600 2
structure pile.
Rock socket drill \c\ (non-impulsive 30-inch concrete guide and 174 10,800 2
component). structure pile.
----------------------------------------------------------------------------------------------------------------
Note: Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters.
\a\ NMFS, 2024.
\b\ NMFS, 2022.
\c\ Rock socket drilling is a DTH activity with multiple strikes per second. DTH activities produce sounds that
simultaneously contain both non-impulsive and impulsive components.
Table 7--Observed Impulsive Sound Levels and Durations for Pile Installation Activities Likely To Occur at Moorings Sitka
--------------------------------------------------------------------------------------------------------------------------------------------------------
SELsingle-strike
Peak (re 1 RMS (dB re 1 (dB re 1 Strikes per Maximum Piles per
Installation method Pile size and type [mu]Pa) at 10 [mu]Pa) at 10 [mu]Pa\2\s) at day strikes day
m m 10 m per pile
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact drive \a\....................... 13-inch plastic fender 177 153 NA 200 100 2
pile.
Impact drive \a\....................... 14-inch timber guide pile 180 170 160 320 160 2
Rock socket drill \b\.................. 30-inch concrete guide 194 174 164 \d\ 216,000 108,000 2
pile.
Impact hammer proofing \c\............. 30-inch concrete guide 198 186 173 10 5 2
pile.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters.
\a\ Caltrans, 2020.
\b\ NMFS, 2022.
\c\ NMFS, 2024.
\d\ Rock socket drilling is a DTH activity with multiple strikes per second. DTH activities produce sounds that simultaneously contain both non-
impulsive and impulsive components.
Level B Harassment Zones--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 x log<INF>10</INF> (R<INF>1</INF>/R<INF>2</INF>),
Where:
[[Page 104096]]
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile, and
R<INF>2</INF> = 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 (-4.5 dB per doubling of distance).
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 USCG's planned activities.
This analysis uses practical spreading loss, a standard assumption
regarding sound propagation for similar environments, to estimate
transmission of sound through water. The Level B harassment zones and
approximate amount of area ensonified for the planned underwater
activities are shown in tables 8 and 9.
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 Updated 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. A weighting adjustment
factor of 2.5 or 2, a standard default value for vibratory pile driving
and removal or impact driving and DTH respectively, was used to
calculate Level A harassment areas. 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 driving and DTH, the optional Updated
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 AUD INJ. Inputs used in the optional Updated
User Spreadsheet tool (e.g., number of piles per day, duration and/or
strikes per pile) are presented in tables 4-7, and the resulting
estimated isopleths and total ensonified areas are reported below in
tables 8 and 9.
Table 8--Projected Distances to Level A Harassment Isopleths Using 2018 and 2024 Technical Guidance and Level B Harassment Isopleths by Marine Mammal
Hearing Group at Moorings Seward
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total
Distance to level A for Distance to Distance to Distance to Distance to Level B ensonified
Activity LF level A for HF level A for level A for PW level A for Distance area
VHF OW (m) (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile extraction............. 10.8 m................... 1 m 16 m 6.6 m 0.5 m 4,641.6 1.94
(14.6 m)................. (5.6 m) (11.9 m) (18.8 m) (6.3 m)
DTH (Impulsive component) concrete.... 1,945.5.................. 69.2 2,317.4 1,041.2 (1,722.1 75.8 39,810.7 * 2.26
(1,938.5 m).............. (247.3 m) (2,999.8 m) m) (641.9 m)
Vibratory settling concrete........... 4.5 m.................... 0.4 m 6.6 m 2.7 m 0.2 m 7,356.4 * 2.26
(6 m).................... (2.3 m) (4.9 m) (7.8 m) (2.6 m)
Impact driver proofing concrete....... 10 m..................... 0.4 m 11.9 m 5.3 m 0.4 m 541.2 0.11
(1.3 m) (15.4 m) (8.8 m) (3.3 m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note 1: Abbreviations: LF = low-frequency cetaceans, HF = high-frequency cetaceans, VHF = very high-frequency cetaceans, PW = phocid pinnipeds in water,
OW = otariid pinnipeds in water.
Note 2: Isopleths based on NMFS (2018) are shown above updated isopleths from NMFS (2024), which are italicized in parentheses below the original
isopleths.
* Total harassment areas are the same despite having varying radii because the maximum distance intersects with the other side of Resurrection Bay near
Seward resulting in the same areal extent.
Table 9--Projected Distances to Level A Harassment Isopleths Using 2018 and 2024 Technical Guidance and Level B Harassment Isopleths by Marine Mammal
Hearing Group at Moorings Sitka
--------------------------------------------------------------------------------------------------------------------------------------------------------
Total
Activity Distance to Distance to Distance to Distance to Distance to Level B ensonified area
level A for LF level A for HF level A for VHF level A for PW level A for OW distance (m) (km\2\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile extraction.... 14.7 m.......... 1.3 m........... 21.7 m.......... 6.9 m........... 0.6 m.......... 6,309.6 m...... 4.17
(19.8 m)........ (7.6 m)......... (16.2 m)........ (25.5 m)........ (8.6 m)........
Impact drive plastic......... 13.6 m.......... 0.5 m........... 16.2 m.......... 7.3 m........... 0.5 m.......... 3.4 m.......... 0
(13.5 m)........ (1.7 m)......... (21 m).......... (12 m).......... (4.5 m)........
Impact drive timber.......... 13.7 m.......... 0.5 m........... 16.3 m.......... 7.3 m........... 0.5 m.......... 46.4 m......... 0.01
(13.6 m)........ (1.7 m)......... (21.1 m)........ (12.1 m)........ (4.5 m)........
DTH (Impulsive component).... 1,945.5 m....... 69.2 m.......... 2,317.4 m....... 1,041.2 m....... 75.8 m......... 39,810.7 m..... 6.31
(1,938.5 m)..... (247.3 m)....... (2,999.8 m)..... (1,722.1 m)..... (641.9 m)......
Vibratory settling concrete.. 4.5 m........... 0.4 m........... 6.6 m........... 2.7 m........... 0.2 m.......... 7,356.4 m...... 4.89
(6 m)........... (2.3 m)......... (4.9 m)......... (7.8 m)......... (2.6 m)........
Impact driver proofing 10 m............ 0.4 m........... 11.9 m.......... 5.3 m........... 0.4 m.......... 541.2 m........ 0.33
concrete. (1.3 m)......... (15.4 m)........ (8.8 m)......... (3.3 m)........
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note 1: Abbreviations: LF = low-frequency cetaceans, HF = high-frequency cetaceans, VHF = very high-frequency cetaceans, PW = phocid pinnipeds in water,
OW = otariid pinnipeds in water.
Note 2: Isopleths based on NMFS (2018) are shown with updated isopleths from NMFS (2024) are italicized in parentheses.
Marine Mammal Occurrence
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information which
informed the take calculations. Available information regarding marine
mammal occurrence and density in the project areas includes monitoring
data, prior
[[Page 104097]]
incidental take authorizations, and ESA consultations on previous
projects. When local density information was not available, data
aggregated in the Navy's Marine Mammal Species Density Database (Navy,
2019; Navy, 2020) for the Northwest or Gulf of Alaska Testing and
Training areas or nearby proxies from the monitoring data were used.
Daily occurrence probability of each marine mammal species is based on
consultation with previous monitoring reports, local researchers and
marine professionals. Occurrence probability estimates at Moorings
Sitka are based on conservative density approximations for each species
and factor in historic data of occurrence, seasonality, and group size
in Sitka Sound and Sitka Channel. A summary of occurrence is shown in
table 10. Group size is based on the best available published research
for these species and their presence in the project areas.
Table 10--Estimated Species Occurrence or Density Values
----------------------------------------------------------------------------------------------------------------
Species Stock Moorings Seward Moorings Sitka
----------------------------------------------------------------------------------------------------------------
Steller sea lion a b................. Western................ 2 individuals/day...... 2 groups of 2
individuals/day of
either stock
Steller sea lion a b................. Eastern................ 0...................... 2 groups of 2
individuals/day of
either stock
Northern fur seal.................... Eastern Pacific........ 0...................... 1 individual/month
Harbor seal.......................... Prince William Sound... 48.95 individuals/day.. 0
Harbor seal \a\...................... Sitka/Chatham Strait... 0...................... 2 groups of 2.1
individuals/day
Killer whale......................... Alaska Resident........ 1 group of 7 1 group of 6.6
individuals/week of individuals/week of
either stock. any stock
Killer whale......................... Gulf of Alaska, 1 group of 7 1 group of 6.6
Aleutian Islands, and individuals/week of individuals/week of
Bering Sea Transient. either stock. any stock
Killer whale......................... Northern Resident...... 0...................... 1 group of 6.6
individuals/week of
any stock
Killer whale......................... West Coast Transient... 0...................... 1 group of 6.6
individuals/week of
any stock
Pacific white-sided dolphin.......... North Pacific.......... 3 individuals/day...... 0
Harbor porpoise...................... Gulf of Alaska......... 0.4547 individuals/ 0
km\2\.
Harbor porpoise...................... Yakutat/Southeast 0...................... 1 group of 5
Alaska Offshore Waters. individuals/week
Dall's porpoise...................... Alaska................. 0.25 individuals/day... 0.121 individuals/km\2\
Sperm whale.......................... North Pacific.......... 0...................... 0.002 individuals/km\2\
Humpback whale \c\................... Hawai'i................ 1 individual/day of 1 group of 3.4
either stock. individuals/week of
either stock
Humpback whale \c\................... Mexico-North Pacific... 1 individual/day of 1 group of 3.4
either stock. individuals/week of
either stock
Gray whale........................... Eastern North Pacific.. 0.0155 individuals/ 1 group of 3.5
km\2\. individuals/2 weeks
Fin whale............................ Northeast Pacific...... 0.068 individuals/km\2\ 0.0001 individuals/
km\2\
Minke whale.......................... Alaska................. 0.006 individuals/km\2\ 1 group of 3.5
individuals/2 weeks
----------------------------------------------------------------------------------------------------------------
Note: Occurrence value presented as individuals per unit time; density value presented as individuals per square
kilometer.
\a\ Likelihood of one group per day in the Level A harassment zone and likelihood of two groups per day in the
Level B harassment zone.
\b\ Steller sea lion stock attribution is 100 percent Western DPS at Moorings Seward; 97.8 percent Eastern DPS
and 2.2 percent Western DPS at Moorings Sitka.
\c\ Humpback whale stock attribution is 89 percent Hawai'i and 11 percent Mexico-North Pacific at Moorings
Seward; 98 percent Hawai'i and 2 percent Mexico-North Pacific at Moorings Sitka.
Gray whale--Members of the ENP stock have a small chance to occur
at the northern end of Resurrection Bay near Moorings Seward, with an
estimated density of 0.0155 individuals/km\2\.
During 190 hours of observation from 1994 to 2002 from Sitka's
Whale Park, only three gray whales were observed (Straley et al.,
2017). However, Straley and Wild (unpublished data) note that since
2014, the number of gray whale sightings in Sitka Sound has increased
to an estimated 150-200 individuals in 2021 and 2022. Based on this and
recent monitoring data collected near Sitka, the estimated occurrence
of gray whales at Moorings Sitka is one group of 3.5 individuals every
2 weeks.
Fin whale--Fin whales have the potential to occur at both Moorings
Seward and Moorings Sitka. Based on survey data, fin whales in the
vicinity of Moorings Seward are anticipated to occur at a density of
0.068/km\2\ and fin whales in the vicinity of Moorings Sitka are
anticipated to occur at a density of 0.0001/km\2\.
Humpback whale--Humpback whales found in the project areas are
predominantly members of the Hawai[revaps]i DPS (89 percent at Moorings
Seward, 98 percent probability at Moorings Sitka), which is not listed
under the ESA. However, based on a comprehensive photo-identification
study, members of the Mexico DPS, which is listed as threatened, have a
small potential to occur in all project locations (11 percent at
Moorings Seward, 2 percent at Moorings Sitka) (Wade, 2016), and it is
estimated that one individual per day of either stock may occur at
Moorings Seward while one group of 3.5 individuals per 2 weeks of
either stock may occur at Moorings Sitka.
Minke whale--Minke whales are generally found in shallow, coastal
waters within 200 m (656 ft) of shore (Zerbini et al., 2006). Dedicated
surveys for cetaceans in southeast Alaska found that minke whales were
scattered throughout inland waters from Glacier Bay and Icy Strait to
Clarence Strait, with small concentrations near the entrance of Glacier
Bay. Surveys took place in spring, summer, and fall, and minke whales
were present in low numbers in all seasons and years (Dahlheim et al.,
2009). Additionally, minke whales were observed during the Biorka
Island Dock Replacement Project at the mouth of Sitka Sound (Turnagain
Marine Construction, 2018). Minke whale density at Moorings Seward is
estimated as 0.006 individuals/km\2\ while estimated occurrence at
Moorings Sitka is one group of 3.5 individuals every 2 weeks.
[[Page 104098]]
Killer whale--Killer whales occur along the entire coast of Alaska
(Braham and Dahlheim, 1982) and four stocks may be present in the
project areas as follows: (1) Alaska Resident stock--both locations;
(2) Gulf of Alaska, Aleutian Islands, and Bering Sea Transient stock--
both locations; (3) Northern Resident--Sitka only; and (4) West Coast
Transient stock--Sitka only.
The Alaska Resident stock occurs from southeast Alaska to the
Aleutian Islands and Bering Sea. The Gulf of Alaska, Aleutian Islands,
and Bering Sea Transient stock occurs from the northern British
Columbia coast to the Aleutian Islands and Bering Sea. The Northern
Resident stock occurs from Washington north through part of southeast
Alaska. The West Coast Transient stock occurs from California north
through southeast Alaska (Muto et al., 2020). One group of seven
individuals per week from either the Alaska Resident stock or the Gulf
of Alaska, Aleutian Islands, and Bering Sea Transient stock are
estimated to occur at Moorings Seward. One group of 6.6 individuals per
week from any of the four stocks are estimated to occur at Moorings
Sitka.
Pacific white-sided dolphin--Pacific white-sided dolphins are
anticipated to occur in the vicinity of Moorings Seward only. Previous
construction monitoring reported by NOAA as an appropriate proxy for
Moorings Seward is three individuals per day. During 8 years of surveys
near Sitka, Straley et al. (2017) only documented seven Pacific white-
sided dolphins, therefore, we do not reasonably expect the species to
occur in the vicinity of Moorings Sitka.
Dall's porpoise--Dall's porpoise are anticipated to occur in the
vicinity of both locations. At Moorings Seward, the expected occurrence
rate is approximately 0.25 animals per day, and the average group size
throughout Alaskan waters is estimated to be between 2 and 12
individuals. We therefore estimate that approximately one group of up
to six individuals could occur over 22 non-consecutive days of in-water
work. At Moorings Sitka, the estimated density of Dall's porpoise is
0.121 individuals/km\2\.
Harbor porpoise--Only the Yakutat/Southeast Alaska Offshore Waters
stock and the Gulf of Alaska stock are expected to be encountered in
the project areas. The Gulf of Alaska stock range includes Moorings
Seward while the Yakutat/Southeast Alaska Offshore Waters stock's range
includes Moorings Sitka. The estimated density of harbor porpoises at
Moorings Seward is 0.4547/km\2\ and the estimated occurrence at
Moorings Sitka is one group of five individuals every week.
Northern fur seal--Northern fur seals are not expected near
Moorings Seward and one individual per month is estimated to occur at
Moorings Sitka.
Steller sea lion--Only the Western stock of Steller sea lion is
expected to occur at Moorings Seward with an estimated occurrence of
two individuals per day. Both the Western and Eastern stocks may occur
at Moorings Sitka, which is located in the Central Outer Coast
population mixing zone delineated by Hastings et al. (2020). Based on
these data, 2.2 percent of Steller sea lions near Sitka are expected to
be from the Western stock while 97.8 percent are expected to be from
the Eastern stock (Hastings et al., 2020), and it is estimated that two
groups of two individuals per day may occur at Moorings Sitka in the
Level A harassment zone.
Harbor seal--There are 12 stocks of harbor seals in Alaska, 2 of
which occur in the project areas: (1) the Prince William Sound stock
ranges from Elizabeth Island off the southwest tip of the Kenai
Peninsula to Cape Fairweather, including Moorings Seward; and (2) the
Sitka/Chatham Strait stock ranges from Cape Bingham south to Cape
Ommaney, extending inland to Table Bay on the west side of Kuiu Island
and north through Chatham Strait to Cube Point off the west coast of
Admiralty Island, and as far east as Cape Bendel on the northeast tip
of Kupreanof Island, which includes Moorings Sitka. Daily occurrence of
harbor seals at Moorings Sitka is estimated as 48.95 individuals/day
and at Moorings Sitka 2 groups of 2.1 individuals/day are estimated
based on previous monitoring in the vicinity, with a likelihood of 2
groups per day in the Level A harassment zone.
Take Estimation
Here we describe how the information provided above was synthesized
to produce a quantitative estimate of the take that is reasonably
likely to occur and is authorized.
Neither the applicant nor NMFS have fine-scale data to
quantitatively assess the number of animals in the relatively small
predicted Level A harassment zones at either location. Therefore, we
assumed that, for cryptic species (e.g., Steller sea lion, Pacific
white-sided dolphin (Moorings Seward only), harbor seal, harbor
porpoise), up to 25 percent of the animals that entered the Level B
harassment zone could enter the Level A harassment zone undetected,
potentially accumulating sound exposure that rises to the level of
Level A harassment.
For species with observational data, the following equation was
used to estimate take by Level B harassment, where daily occurrence is
measured as individuals per day:
Estimated take = (daily occurrence x number of days)-Level A harassment
takes
For species with observational data, the following equation was
used to estimate take by Level A harassment, where daily occurrence is
multiplied by the number of days of work, which is then multiplied by
25 percent:
Estimated take = (daily occurrence x number of days) x 25 percent
For species with density data, the following equation was used to
estimate take by Level B harassment, where ensonified area is measured
as km\2\:
Estimated take = (species density x daily ensonified Level B harassment
area x number of days)--Level A harassment takes
For species with density data, the following equation was used to
estimate take by Level A harassment, where species density is
multiplied by the daily ensonified Level A harassment area multiplied
by the number of days of work:
Estimated take = species density x daily ensonified Level A harassment
area x number of days
Table 11 summarizes the amount of take authorized by both Level A
and Level B harassment, as well as the percentage of each stock
expected to be taken, at Moorings Seward.
Table 11--Authorized Take of Marine Mammals by Level A and Level B Harassment at Moorings Seward
--------------------------------------------------------------------------------------------------------------------------------------------------------
SAR Percentage of
Species Stock Level A Level B Total abundance population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion................................ Western........................... 10 34 44 49,837 0.09
Harbor seal..................................... Prince William Sound.............. 245 833 1078 44,756 2.41
Killer whale *.................................. Alaska Resident................... 0 21 21 1,920 1.09
[[Page 104099]]
Killer whale *.................................. Eastern North Pacific Gulf of 0 7 7 587 1.19
Alaska, Aleutian Islands and
Bering Sea Transient.
Pacific white-sided dolphin..................... North Pacific..................... 15 51 66 26,880 0.25
Harbor porpoise................................. Gulf of Alaska.................... 8 15 23 31,046 0.07
Dall's porpoise................................. Alaska............................ 1 5 6 UND UND
Humpback whale.................................. Hawai[revaps]i.................... 0 20 20 11,278 0.18
Humpback whale.................................. Mexico-North Pacific.............. 0 2 2 N/A N/A
Gray whale...................................... Eastern North Pacific............. 0 1 1 26,960 0
Fin whale....................................... Northeast Pacific................. 0 3 3 UND UND
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Humpback whale stock attribution: 89 percent Hawai[revaps]i and 11 percent Mexico-North Pacific.
* Percent of stock impacted for killer whales was estimated assuming each stock is taken in proportion to its population size at each location from the
total take. At Moorings Seward, the Alaska Resident and Gulf of Alaska stocks are the only stocks present. Of these, the Alaska Resident stock
represents approximately 76 percent of the available animals, while the Gulf of Alaska stock represents approximately 23 percent. Takes were then
calculated for each site based on the proportional representation of available stocks, so for Moorings Seward, this results in 21 Level B harassment
takes of the Alaska Resident stock of killer whale and 7 Level B harassment takes of the Gulf of Alaska stock of killer whale. Total takes for each
stock are shown as a percentage of the stock size.
Table 12 summarizes amount of take authorized by both Level A and
Level B harassment, as well as the percentage of each stock expected to
be taken, at Moorings Sitka.
Table 12--Authorized Take of Marine Mammals by Level A and Level B Harassment at Moorings Sitka
--------------------------------------------------------------------------------------------------------------------------------------------------------
Percentage of
Species Stock Level A Level B Total SAR abundance population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steller sea lion.......................... Western..................... 2 6 8 49,837 0.02
Steller sea lion.......................... Eastern..................... 82 270 352 36,308 0.97
Northern fur seal......................... Eastern Pacific............. 0 3 3 626,618 0
Harbor seal............................... Sitka/Chatham Strait........ 88 272 360 13,289 2.71
Killer whale *............................ Alaska Resident............. 0 55 55 1,920 2.86
Killer whale *............................ Eastern North Pacific Gulf 0 17 17 587 2.90
of Alaska, Aleutian Islands
and Bering Sea Transient.
Killer whale *............................ Northern Resident........... 0 8 8 302 2.65
Killer whale *............................ West Coast Transient........ 0 10 10 349 2.87
Harbor porpoise........................... Yakutat/Southeast Alaska 15 20 35 N/A N/A
Offshore Waters.
Dall's porpoise........................... Alaska...................... 24 42 66 UND UND
Humpback whale............................ Hawai[revaps]i.............. 0 43 43 11,278 0.38
Humpback whale............................ Mexico-North Pacific........ 0 1 1 N/A N/A
Gray whale................................ Eastern North Pacific....... 0 22 22 26,960 0.08
Minke whale............................... Alaska...................... 0 22 22 N/A N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Steller sea lion stock attribution: 97.8 percent Eastern DPS and 2.2 percent Western DPS at Moorings Sitka. Humpback whale stock attribution: 98
percent Hawai[revaps]i and 2 percent Mexico-North Pacific.
* Percent of stock impacted for killer whales was estimated assuming each stock is taken in proportion to its population size at each location from the
total take. At Moorings Sitka, the Alaska Resident, Gulf of Alaska, Northern Resident, and West Coast Transient stocks are expected, and the Alaska
Resident stock represents approximately 60 percent of the available animals, the Gulf of Alaska stock represents approximately 19 percent, the
Northern Resident stock represents approximately 10 percent, and the West Coast Transient represents approximately 11 percent. Takes were then
calculated based on the proportional representation of available stocks, which results in 55 Level B harassment takes of the Alaska Resident stock, 17
Level B harassment takes of the Gulf of Alaska stock, 8 Level B harassment takes of the Northern Resident stock, and 10 Level B harassment takes of
the West Coast Transient stock. Total takes for each stock are shown as a percentage of the stock size.
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. 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
[[Page 104100]]
mammals, marine mammal species or stocks, and their habitat, as well as
subsistence uses. 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.
For each IHA, the USCG must:
<bullet> Ensure that construction supervisors and crews, the
monitoring team, and relevant USCG staff are trained prior to the start
of all pile driving and DTH activity, so that responsibilities,
communication procedures, monitoring protocols, and operational
procedures are clearly understood. New personnel joining during the
project must be trained prior to commencing work;
<bullet> Employ one to five PSOs and establish monitoring locations
as described in the application and the IHA. The USCG must monitor the
project area to the maximum extent possible based on the required
number of PSOs, required monitoring locations, and environmental
conditions. For all pile driving and removal at least one PSO must be
used. The PSO will be stationed as close to the activity as possible;
<bullet> The placement of the PSOs during all pile driving and
removal and DTH activities will ensure that the entire shutdown zone is
visible during pile installation;
<bullet> Monitoring must take place from 30 minutes prior to
initiation of pile driving or DTH activity (i.e., pre-activity
monitoring) through 30 minutes post-activity of pile driving or DTH
activity;
<bullet> Pre-activity monitoring must be conducted during periods
of visibility sufficient for the lead PSO to determine that the
shutdown zones indicated in table 13 are clear of marine mammals. Pile
driving and DTH may commence following 30 minutes of observation when
the determination is made that the shutdown zones are clear of marine
mammals;
<bullet> The USCG must use soft start techniques when impact pile
driving. Soft start requires contractors to provide an initial set of
three strikes at reduced energy, followed by a 30-second waiting
period, then two subsequent reduced-energy strike sets. A soft start
must be implemented at the start of each day's impact pile driving and
at any time following cessation of impact pile driving for a period of
30 minutes or longer; and
<bullet> If a marine mammal is observed entering or within the
shutdown zones indicated in table 13, pile driving and DTH must be
delayed or halted. If pile driving is delayed or halted due to the
presence of a marine mammal, the activity may not commence or resume
until either the animal has voluntarily exited and been visually
confirmed beyond the shutdown zone (table 13) or 15 minutes have passed
without re-detection of the animal.
As proposed by the applicant, in-water activities will take place
only between civil dawn and civil dusk (generally 30 minutes after
sunrise and up to 45 minutes before sunset), and work may not begin
without sufficient daylight to conduct pre-activity monitoring, and may
extend up to 3 hours past sunset, as needed to either completely remove
an in-process pile or to embed a new pile far enough to safely leave
piles in place until work can resume the next day; during conditions
with a Beaufort Sea State of four or less; and when the entire shutdown
zones are visible.
Protected Species Observers
The placement of PSOs during all pile driving activities (described
in Monitoring and Reporting) will ensure that the entire shutdown zone
is visible. Should environmental conditions deteriorate such that the
entire shutdown zone will not be visible (e.g., fog, heavy rain), pile
driving will be delayed until the PSO is confident marine mammals
within the shutdown zone could be detected.
PSOs will monitor the full shutdown zones and the Level B
harassment zones to the extent practicable. Monitoring zones provide
utility for observing by establishing monitoring protocols for areas
adjacent to the shutdown zones. Monitoring zones enable observers to be
aware of and communicate the presence of marine mammals in the project
areas outside the shutdown zones and thus prepare for a potential
cessation of activity should the animal enter the shutdown zone.
Pre- and Post-Activity Monitoring
Monitoring must take place from 30 minutes prior to initiation of
pile driving activities (i.e., pre-clearance monitoring) through 30
minutes post-completion of pile driving. Prior to the start of daily
in-water construction activity, or whenever a break in pile driving of
30 minutes or longer occurs, PSOs will observe the shutdown and
monitoring zones for a period of 30 minutes. The shutdown zone will be
considered cleared when a marine mammal has not been observed within
the zone for a 30-minute period. If a marine mammal is observed within
the shutdown zones listed in table 9, pile driving activity will be
delayed or halted. If work ceases for more than 30 minutes, the pre-
activity monitoring of the shutdown zones will commence. A
determination that the shutdown zone is clear must be made during a
period of good visibility (i.e., the entire shutdown zone and
surrounding waters must be visible to the naked eye).
Soft-Start Procedures for Impact Driving
Soft-start procedures 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. If
impact pile driving is necessary to achieve required tip elevation, the
USCG is 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 must be
implemented at the start of each day's impact pile driving and at any
time following cessation of impact pile driving for a period of 30
minutes or longer.
Shutdown Zones
The USCG must establish shutdown zones for all pile driving
activities. The purpose of a shutdown zone is generally to define an
area within which shutdown of the activity would occur upon sighting of
a marine mammal (or in anticipation of an animal entering the defined
area). Shutdown zones are based upon the Level A harassment thresholds
for each pile size/type and driving method where applicable, as shown
in table 13. During all in-water piling activities, the USCG plans to
implement a minimum 30-m shutdown zone, larger than NMFS' typical
requirement of a minimum 10-m shutdown zone, with the addition of
larger zones during DTH. These distances exceed the estimated Level A
harassment isopleths described in tables 8 and 9. Adherence to this
expanded shutdown zone will reduce the potential for the take of marine
mammals by Level A harassment but, due to the large zone sizes and
small, inconspicuous nature of five species (Steller sea lion, Pacific
white-sided dolphin (Moorings Seward only), harbor seal, harbor
porpoise, Dall's porpoise), the potential for Level A harassment cannot
be completely avoided. If a marine
[[Page 104101]]
mammal is observed entering, or detected within, a shutdown zone during
pile driving activity, the activity must be stopped until there is
visual confirmation that the animal has left the zone or the animal is
not sighted for a period of 15 minutes. Shutdown zones for each
activity type are shown in table 13.
All marine mammals would be monitored in the Level B harassment
zones and throughout the area as far as visual monitoring can take
place. If a marine mammal enters the Level B harassment zone, in-water
activities will continue and PSOs will document the animal's presence
within the estimated harassment zone.
Table 13--Shutdown Zones and Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level B Level B
Shutdown Shutdown Shutdown Shutdown Shutdown harassment harassment
Activity zone (m) zone (m) zone (m) zone (m) zone (m) zone (m) at zone (m) at
for LF for HF for VHF for PW for OW Seward Sitka
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory pile extraction.............................. 30 30 30 30 30 4,645 6,310
Impact drive plastic pile.............................. 30 30 30 30 30 N/A 5
Impact drive timber pile............................... 30 30 30 30 30 N/A 50
DTH (Impulsive component) concrete pile................ 1,955 85 2,325 1,050 85 39,815 39,815
Vibratory concrete pile settling....................... 30 30 30 30 30 7,360 7,360
Impact drive concrete pile proofing.................... 30 30 30 30 30 545 545
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Level A (AUD INJ onset) harassment will only potentially result from DTH rock socket drilling activities that will generate underwater noise in
exceedance of Level A harassment thresholds for all marine mammal hearing groups beyond the 30-m shutdown zone that will be implemented for all in-
water activities. Therefore, larger shutdown zones will be implemented during DTH activities and at least two additional PSOs will be assigned to a
captained vessel at one or more monitoring locations that provide full views of the shutdown zones and as much of the monitoring zones as possible.
Based on our evaluation of the applicant's planned measures, NMFS
has determined that the planned 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.
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 must be conducted in accordance with the
conditions in this section and this IHA. Marine mammal monitoring
during pile driving activities would be conducted by up to five 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 other relevant experience,
education (degree in biological science or related field), or training
for prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued incidental take authorization;
<bullet> A team of three PSOs (up to five PSOs) at up to three
locations (including two PSOs on a captained vessel in the case of a
five-member team) will conduct the marine protected species monitoring
depending on the activity and size of the relevant shutdown and
monitoring zones;
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator must be designated. The lead
observer must have prior experience performing the duties of a PSO
during construction activity pursuant to a NMFS-issued incidental take
authorization;
<bullet> For activities with monitoring zones beyond the visual
range of a single PSO (i.e., DTH), additional monitoring locations or
the use of a vessel with captain and up to three other PSOs (depending
on size of the monitoring zones) will conduct monitoring; and
<bullet> PSOs must be approved by NMFS prior to beginning any
activity subject to the 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
[[Page 104102]]
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.
For all pile driving activities, at least one PSO must be stationed
at the best possible vantage point to monitor the shutdown zones and as
much of the Level B harassment zones as possible. A team of three or
five PSOs at up to three locations (including two PSOs on a captained
vessel in the case of a five-member team) would conduct marine mammal
monitoring depending on the activity and size of monitoring zones. PSOs
would be equipped with high quality binoculars for monitoring and
radios or cells phones for maintaining contact with work crews.
Monitoring would be conducted 30 minutes before, during, and 30 minutes
after all in-water construction activities. In addition, PSOs 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.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities for each IHA, or 60 days prior to a requested date of
issuance from any future IHAs for projects at the same location,
whichever comes first. The report will include an overall description
of work completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. The USCG must submit all PSO data
electronically in a format that can be queried such as a spreadsheet or
database (i.e., digital images of data sheets are not sufficient).
Specifically, the report must include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> Construction activities occurring during each daily
observation period, including the number and type of piles driven or
removed and by what method (i.e., impact, vibratory, DTH) and the total
equipment duration for vibratory removal for each pile or total number
of strikes for each pile (impact driving);
<bullet> PSO locations during marine mammal monitoring;
<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;
<bullet> Upon observation of a marine mammal, the following
information:
[cir] Name of PSO who sighted the animal(s) and PSO location and
activity at the time of sighting;
[cir] Time of sighting;
[cir] Identification of the animal(s) (e.g., genus/species, lowest
possible taxonomic level, or unidentifiable), PSO confidence in
identification, and the composition of the group if there is a mix of
species;
[cir] Distance and bearing of each marine mammal observed relative
to the pile being driven for each sighting (if pile driving was
occurring at time of sighting);
[cir] Estimated number of animals (min/max/best estimate);
[cir] Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, sex class, etc.);
[cir] Animal's closest point of approach and estimated time spent
within the harassment zone; and
[cir] 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 and shutdown zones; by species; and
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensured, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
reports will constitute the final reports. If comments are received, a
final report addressing NMFS comments must be submitted within 30 days
after receipt of comments.
Reporting Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the USCG must immediately
cease the specified activities and report the incident to the Office of
Protected Resources (<a href="/cdn-cgi/l/email-protection#a3f3f18deaf7f38deecccdcad7ccd1cacdc4f1c6d3ccd1d7d0e3cdccc2c28dc4ccd5"><span class="__cf_email__" data-cfemail="b8e8ea96f1ece896f5d7d6d1ccd7cad1d6dfeaddc8d7cacccbf8d6d7d9d996dfd7ce">[email protected]</span></a> and
<a href="/cdn-cgi/l/email-protection#6c25383c420f00091a09021f180502092c02030d0d420b031a"><span class="__cf_email__" data-cfemail="fcb5a8acd29f90998a99928f88959299bc92939d9dd29b938a">[email protected]</span></a>), NMFS, and to the Alaska Regional Stranding
Coordinator as soon as feasible. If the death or injury was clearly
caused by the specified activity, the USCG must immediately cease the
specified activities until NMFS is able to review the circumstances of
the incident and determine what, if any, additional measures are
appropriate to ensure compliance with the terms of the IHA. The IHA-
holder must not resume their activities until notified by NMFS. The
report must include the following information:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> 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,
[[Page 104103]]
1989), the impacts from other past and ongoing anthropogenic activities
are incorporated into this analysis via their impacts on the baseline
(e.g., as reflected in the regulatory status of the species, population
size and growth rate where known, ongoing sources of human-caused
mortality, or ambient noise levels).
To avoid repetition, the discussion of our analysis applies to all
the species listed in table 1 at both project locations, given that the
anticipated effects of this activity on these different marine mammal
stocks are expected to be similar in Seward and Sitka. There is little
information about the nature or severity of the impacts, or the size,
status, or structure of any of these species or stocks that would lead
to a different analysis for this activity.
Pile driving and DTH activities associated with the specified
activities, as described previously, have the potential to disturb or
displace marine mammals. Specifically, the specified activities may
result in take in the form of Level B harassment only for all species
other than the Steller sea lion, harbor seal, Pacific white-sided
dolphin, harbor porpoise, and Dall's porpoise from underwater sounds
generated from pile driving and DTH. Potential takes could occur if
individual marine mammals are present in the ensonified areas when pile
driving or DTH is occurring.
No serious injury or mortality would be expected, even in the
absence of required mitigation measures, given the nature of the
activities. For all species other than Steller sea lion, harbor seal,
Pacific white-sided dolphin, harbor porpoise, and Dall's porpoise, no
Level A harassment is anticipated due to the confined nature of the
facilities, ability to position PSOs at stations from which they can
observe the entire shutdown zones, and the high visibility of the
species expected to be present at each site. The potential for injury
is small for mid- and low-frequency cetaceans and sea lions, and is
expected to be essentially eliminated through implementation of the
planned mitigation measures--soft start (for impact driving), and
shutdown zones. Further, no take by Level A harassment is anticipated
for killer whales, humpback whales, gray whales, fin whales, or minke
whales due to the application of planned mitigation measures and the
small Level A harassment zones (for killer whales only). The potential
for harassment will be minimized through the construction method and
the implementation of the planned mitigation measures (see Mitigation
section).
Take by Level A harassment is authorized for Steller sea lion,
harbor seal, Pacific white-sided dolphin, harbor porpoise, and Dall's
porpoise. Due to their inconspicuous nature, it is possible individuals
of these species could enter the Level A harassment zone undetected and
remain within that zone for a duration long enough to incur AUD INJ.
Any take by Level A harassment is expected to arise from, at most, a
small degree of AUD INJ (i.e., minor degradation of hearing
capabilities within regions of hearing that align most completely with
the energy produced by impact pile driving such as the low-frequency
region below 2 kHz), not severe hearing impairment or impairment within
the ranges of greatest hearing sensitivity. Animals would need to be
exposed to higher levels and/or longer duration than are expected to
occur here in order to incur any more than a small degree of AUD INJ.
In summary and as described above, the following factors primarily
support our 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 would be very small amounts and of low
degree;
<bullet> Level B harassment would be primarily in the form of
behavioral disturbance, resulting in avoidance of the project areas
around where piling is occurring, with some low-level TTS that may
limit the detection of acoustic cues for relatively brief amounts of
time in relatively confined footprints of the activities;
<bullet> The ensonified areas are very small relative to the
overall habitat ranges of all species and stocks, and would not
adversely affect ESA-designated critical habitat for any species or any
areas of known biological importance;
<bullet> The amount of take authorized accounts for no more than,
at most, 3 percent of any stock that may occur in the project areas;
<bullet> The lack of anticipated significant or long-term negative
effects to marine mammal habitat; and
<bullet> The implementation of mitigation measures to minimize the
number of marine mammals exposed to injurious levels of sound and
ensure take by Level A harassment is, at most, a small degree of AUD
INJ.
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 planned monitoring and
mitigation measures, NMFS finds that the total marine mammal take from
the 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.
The amount of take NMFS has authorized is below one-third of the
estimated stock abundance of all species and stocks (take of
individuals is less than 3 percent of the abundance of the affected
stocks at Moorings Seward and Moorings Sitka; see tables 11 and 12).
This is likely a conservative estimate because it assumes all takes are
of different individual animals, which is likely not the case. Some
individuals may return multiple times in a day but PSOs would count
them as separate takes if they cannot be individually identified.
There are no valid abundance estimates available for humpback
whales (Mexico-North Pacific stock), fin whales (Northeast Pacific
stock), minke whales (Alaska stock), Dall's porpoises (Alaska stock),
and harbor porpoises (Yakutat/Southeast Alaska Offshore Waters stock).
There is no recent stock abundance estimate for the Mexico-North
Pacific stock of humpback whale and the minimum population is
considered unknown (Young et al., 2023). There are 2 minimum population
estimates for this stock that are over 15 years old: 2,241
(Mart[iacute]nez-Aguilar, 2011) and 766 (Wade, 2021). Using either of
these estimates, the three takes by Level B harassment authorized (two
at Moorings Seward, one at Moorings Sitka) represent small numbers of
the stock. Muto et al. (2021) estimate the minimum stock size for the
Northeast Pacific stock of fin whale for the areas
[[Page 104104]]
surveyed is 2,554 individuals. Therefore, the three takes by Level B
harassment of this stock at Moorings Seward represent small numbers of
this stock. There is also no current abundance estimate of the Alaska
stock of minke whale but over 2,000 individuals were documented in
areas recently surveyed (Muto et al., 2021). Therefore, the 22 takes by
Level B harassment at Moorings Sitka represent small numbers of this
stock, even if each take occurred to a new individual.
The most recent stock abundance estimate of the Alaska stock of
Dall's porpoise was 83,400 animals and, although the estimate is more
than 8 years old, it is unlikely this stock has drastically declined
since that time. Therefore, the 72 takes authorized, 15 by Level A and
57 by Level B harassment (6 total at Moorings Seward, 66 total at
Moorings Sitka), represent small numbers of this stock. A current
stock-wide abundance estimate for the Yakutat/Southeast Alaska Offshore
Waters stock of harbor porpoises in offshore waters (which includes
Moorings Sitka) is not available (Young et al., 2023). However, Muto et
al. (2021) estimate the minimum stock size for the areas surveyed is
1,057 individuals. Therefore, the 35 takes authorized at Moorings Sitka
(3 by Level A harassment, 32 by Level B harassment) represent small
numbers of this stock.
Based on the analysis contained herein of the activity (including
the planned mitigation and monitoring measures) and the anticipated
take of marine mammals, NMFS finds that small numbers of marine mammals
would be taken relative to the population size of the affected species
or stocks.
Unmitigable Adverse Impact Analysis and Determination
In order to issue an IHA, NMFS must find that the specified
activity will not have an ``unmitigable adverse impact'' on the
subsistence uses of the affected marine mammal species or stocks by
Alaskan Natives. NMFS has defined ``unmitigable adverse impact'' in 50
CFR 216.103 as an impact resulting from the specified activity: (1)
That is likely to reduce the availability of the species to a level
insufficient for a harvest to meet subsistence needs by: (i) Causing
the marine mammals to abandon or avoid hunting areas; (ii) Directly
displacing subsistence users; or (iii) Placing physical barriers
between the marine mammals and the subsistence hunters; and (2) That
cannot be sufficiently mitigated by other measures to increase the
availability of marine mammals to allow subsistence needs to be met.
There are two species of marine mammals analyzed herein that have
been taken as part of subsistence harvests in Resurrection Bay and
southeast Alaska: Steller sea lion and harbor seal. The most recent
data on subsistence-harvested marine mammals near Seward is of harbor
seals in 2002, and the most recent data near Sitka is of both harbor
seals and Steller sea lions in 2013 (ADFG, 2013). The most recent
subsistence hunt survey data available indicated approximately 11
percent of Sitka households used subsistence-caught marine mammals
(Sill and Koster, 2013) and no data is available since that time.
The project is not likely to adversely impact the availability of
any marine mammal species or stocks that are commonly used for
subsistence purposes or impact subsistence harvest of marine mammals in
the region. Although the activities are located in regions where
subsistence harvests have occurred historically, subsistence harvest of
marine mammals is rare in the project areas and local subsistence users
have not expressed concern about this project. Both locations are
adjacent to heavily traveled industrialized waterways and all project
activities will take place within closed and secured waterfronts where
subsistence activities do not generally occur. The project also will
not have an adverse impact on the availability of marine mammals for
subsistence use at locations farther away, where the construction
activities are not expected to take place. Some minor, short-term
harassment of Steller sea lions and harbor seals could occur, but any
effects on subsistence harvest activities in the project areas will be
minimal, and not have an adverse impact.
Based on the description of the specified activity and the measures
described to minimize adverse effects on the availability of marine
mammals for subsistence purposes, and the planned mitigation and
monitoring measures, NMFS has determined that there will not be an
unmitigable adverse impact on subsistence uses from the USCG's
activities.
Endangered Species Act
Section 7(a)(2) of the ESA of 1973 (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, in this case with the Alaska Regional Office.
There are three marine mammal species (Western DPS Steller sea
lion, Mexico-North Pacific stock of humpback whale, and the Northeast
Pacific stock of fin whale) with confirmed occurrence in the project
areas that are listed as endangered under the ESA. The NMFS Alaska
Regional Office Protected Resources Division issued a Biological
Opinion on December 3, 2024, under section 7 of the ESA, on the
issuance of an IHA to the USCG under section 101(a)(5)(D) of the MMPA
by the NMFS Permits and Conservation Division. The Biological Opinion
concluded that the proposed action is not likely to jeopardize the
continued existence of Western DPS Steller sea lion, Mexico DPS of
humpback whale, the Western North Pacific DPS of humpback whale, or the
Northeast Pacific stock of fin whale, and is not likely to destroy or
adversely modify critical habitat for Western DPS Steller sea lion,
Mexico DPS of humpback whale, the Western North Pacific DPS of humpback
whale, or the Northeast Pacific stock of fin whale.
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 determined that the
issuance of these IHAs qualify to be categorically excluded from
further NEPA review.
Authorization
NMFS has issued 2 IHAs to the USCG for the potential harassment of
small numbers of 11 marine mammal species incidental to construction of
FRC homeporting docks in Seward and Sitka, Alaska, that includes the
previously explained mitigation, monitoring, and reporting
requirements.
[[Page 104105]]
Dated: December 17, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2024-30455 Filed 12-19-24; 8:45 am]
BILLING CODE 3510-22-P
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