[Federal Register Volume 89, Number 48 (Monday, March 11, 2024)]
[Notices]
[Pages 17423-17439]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-05105]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD533]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Eareckson Air Station Fuel Pier 
Repair in Alcan Harbor on Shemya Island, Alaska

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; issuance of an incidental harassment authorization.

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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 an incidental harassment authorization (IHA) to 
the Pacific Air Forces Regional Support Center (USAF) to incidentally 
harass marine mammals during construction activities associated with 
the Eareckson Air Station (EAS) Fuel Pier Repair in Alcan Harbor, 
Shemya Island, Alaska. There are no changes from the proposed 
authorization in this final authorization.

DATES: This authorization is effective from April 1, 2024 through March 
31, 2025.

ADDRESSES: Electronic copies of the application and supporting 
documents, as well as a list of the references cited in this document 
cited in this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems 
accessing these documents, please call the contact listed below.

FOR FURTHER INFORMATION CONTACT: Kate Fleming, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed IHA is provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable adverse 
impact'' on the affected species or stocks and their habitat, paying 
particular attention to rookeries, mating grounds, and areas of similar 
significance, and on the availability of the species or stocks for 
taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of the takings are set forth. The definitions 
of all applicable MMPA

[[Page 17424]]

statutory terms cited above are included in the relevant sections 
below.

Summary of Request

    On May 15, 2023, NMFS received a request from the USACE on behalf 
of USAF for an IHA to take marine mammals incidental to construction 
associated with the EAS Fuel Pier Repair in Alcan Harbor on Shemya 
Island, Alaska. Following NMFS' review of the application, and 
discussions between NMFS and USAF, the application was deemed adequate 
and complete on September 19, 2023. The USAF's request is for take of 
12 species of marine mammals, by Level B harassment and, for a subset 
of these species, Level A harassment. Neither USAF nor NMFS expect 
serious injury or mortality to result from this activity and, 
therefore, an IHA is appropriate. There are no changes from the 
proposed IHA to the final IHA.
    The IHA will be effective from April 1, 2024 to March 31, 2025.

Description of the Specified Activity

    The USAF plans to conduct long-term repairs on the only existing 
fuel pier at EAS on Shemya Island, Alaska. The activities that have the 
potential to take marine mammals, by Level A harassment and Level B 
harassment, include down-the-hole (DTH) drilling, vibratory and impact 
installation of temporary and permanent steel pipe piles, and vibratory 
removal of temporary steel pipe piles, and would introduce underwater 
sounds that may result in take, by Level A harassment and Level B 
harassment, of marine mammals. The marine construction associated with 
the planned activities is planned to occur over 160 days over 1 year, 
accounting for weather delays and mechanical issues. The IHA is 
effective from April 1, 2024 to March 31, 2025.
    The fuel pier replacement project would include the installation of 
an interlocking steel pipe combi-wall system, which will require the 
installation and removal of 60 30-inch (in) temporary steel pipe piles 
and the installation of 208 42-in round steel interlocking pipe piles 
using vibratory, impact, and/or DTH methods.
    A detailed description of the planned construction project is 
provided in the Federal Register notice for the proposed IHA (88 FR 
74451, October 31, 2023). 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.

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to USAF was published in 
the Federal Register on October 31, 2023 (88 FR 74451). That notice 
described, in detail, USAF'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 
authorization described therein, our analyses, the proposed 
authorization, and any other aspect of the notice of proposed IHA, and 
requested that interested persons submit relevant information, 
suggestions, and comments. During the 30-day public comment period, the 
United States Geological Survey noted that they have ``no comment at 
this time.'' NMFS received no other public comments.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, instead of reprinting the information. Additional 
information regarding population trends and threats may be found in 
NMFS' Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS' website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all species or stocks for which take is expected and 
authorized for this activity, and summarizes information related to the 
population or stock, including regulatory status under the MMPA and 
Endangered Species Act (ESA) and potential biological removal (PBR), 
where known. PBR is defined by the MMPA as the maximum number of 
animals, not including natural mortalities, that may be removed from a 
marine mammal stock while allowing that stock to reach or maintain its 
optimum sustainable population (as described in NMFS' SARs). While no 
serious injury or mortality is anticipated or authorized here, PBR and 
annual serious injury and mortality from anthropogenic sources are 
included here as gross indicators of the status of the species or 
stocks and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS' stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS' U.S. Alaska 2022 SARs (Young et al., 2023). All values presented 
in table 1 are the most recent available at the time of publication and 
are available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                              Table 1--Species Likely Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA  status;   Stock abundance  (CV,
             Common name                  Scientific name               Stock            strategic  (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\         abundance  survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae:
    Fin Whale.......................  Balaenoptera physalus..  Northeast Pacific......  E, D, Y             UND (UND, UND, 2013)          UND        0.6
                                                                                                             \4\.
    Humpback Whale..................  Megaptera novaeangliae.  Western North Pacific..  E, D, Y             1,084, (0.088, 1,007,           3        2.8
                                                                                                             2006).
                                                               Mexico--North Pacific..  T, D, Y             N/A (N/A, N/A, 2006)          UND       0.56
                                                                                                             \5\.
                                                               Hawai[revaps]i.........  -, -, N             11,278 (0.56, 7,265,          127       19.6
                                                                                                             2020).
    Minke Whale.....................  Balaenoptera             Alaska.................  -, -, -             N/A (N/A, N/A, N/A)           UND          0
                                       acutorostrata.                                                        \6\.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 17425]]

 
                                                  Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Physeteridae:
    Sperm whale.....................  Physeter macrocephalus.  North Pacific..........  E, D, Y             UND (UND, UND, 2015)          UND        3.5
                                                                                                             \7\.
Family Ziphiidae (beaked whales):
    Baird's beaked whale............  Berardius bairdii......  Alaska.................  -, -, N             N/A (N/A, N/A, N/A)\          N/A          0
                                                                                                             8\.
    Stejneger's Beaked Whale........  Mesoplodon stejnegeri..  Alaska.................  -, -, N             N/A (N/A, N/A, N/A)\          N/A          0
                                                                                                             8\.
Family Delphinidae:
    Killer Whale....................  Orcinus orca...........  ENP Alaska Resident      -, -, N             1,920 (N/A, 1,920,             19        1.3
                                                                Stock.                                       2019).
                                                               ENP Gulf of Alaska,      -, -, N             587 (N/A, 587, 2012)..        5.9        0.8
                                                                Aleutian Islands, and
                                                                Bering Sea.
Family Phocoenidae (porpoises):
    Dall's Porpoise.................  Phocoenoides dalli.....  Alaska.................  -, -, N             UND (UND, UND, 2015)          UND         37
                                                                                                             \9\.
    Harbor Porpoise.................  Phocoena phocoena......  Bering Sea.............  -, -, Y             UNK (UNK, N/A, 2008)          UND        0.4
                                                                                                             \10\.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions):
    Northern Fur Seal...............  Callorhinus ursinus....  Eastern Pacific........  -, D, Y             626,618 (0.2, 530,376,     11,403        373
                                                                                                             2019).
    Steller Sea Lion................  Eumetopias jubatus.....  Western, U.S...........  E, D, Y             52,932 (N/A, 52,932,          318        254
                                                                                                             2019).
Family Phocidae (earless seals):
    Harbor Seal.....................  Phoca vitulina.........  Aleutian Islands.......  -, -, N             5,588 (N/A, 5,366,             97         90
                                                                                                             2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.nmfs.noaa.gov/pr/sars. CV is coefficient of variation; Nmin is the minimum
  estimate of stock abundance. In some cases, CV is not applicable (explain if this is the case).
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury 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.
\4\ The best available abundance estimate for this stock is not considered representative of the entire stock as surveys were limited to a small portion
  of the stock's range. Based upon this estimate and the Nmin, the PBR value is likely negatively biased for the entire stock.
\5\ Abundance estimates are based upon data collected more than 8 years ago and therefore current estimates are considered unknown.
\6\ Reliable population estimates are not available for this stock. Please see Friday et al. (2013) and Zerbini et al. (2006) for additional information
  on numbers of minke whales in Alaska.
\7\ The most recent abundance estimate is likely unreliable as it covered a small area that may not have included females and juveniles, and did not
  account for animals missed on the trackline. The calculated PBR is not a reliable index for the stock as it is based upon negatively biased minimum
  abundance estimate.
\8\ Reliable abundance estimates for this stock are currently unavailable.
\9\ The best available abundance estimate is likely an underestimate for the entire stock because it is based upon a survey that covered only a small
  portion of the stock's range.
\10\ The best available abundance estimate and Nmin are likely an underestimate for the entire stock because it is based upon a survey that covered only
  a small portion of the stock's range. PBR for this stock is undetermined due to this estimate being older than 8 years.

    As indicated above, all 12 species (with 15 managed stocks) in 
table 1 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur. All species that could 
potentially occur in the project area are included in table 3-1 of the 
IHA application. While blue whale, gray whale, North Pacific right 
whale, Pacific white-sided dolphin, and ribbon seal could occur in the 
area, the temporal and/or spatial occurrence of these species is such 
that take is not expected to occur, and they are not discussed further 
beyond the explanation provided here. These species all have extremely 
low abundance and most are observed in areas outside of the project 
area.
    In addition, northern sea otter may be found the western Aleutians. 
However, this species is managed by the U.S. Fish and Wildlife Service 
and is not considered further in this document.
    A detailed description of the of the species likely to be affected 
by the USAF's 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 (88 FR 
74451, October 31, 2023); 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 (https://www.fisheries.noaa.gov/find-species) 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 to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential

[[Page 17426]]

techniques) or estimated hearing ranges (behavioral response data, 
anatomical modeling, etc.). Note that no direct measurements of hearing 
ability have been successfully completed for mysticetes (i.e., low-
frequency cetaceans). Subsequently, NMFS (2018) described generalized 
hearing ranges for these marine mammal hearing groups. Generalized 
hearing ranges were chosen based on the approximately 65-decibel (dB) 
threshold from the normalized composite audiograms, with the exception 
for lower limits for low-frequency cetaceans where the lower bound was 
deemed to be biologically implausible and the lower bound from Southall 
et al. (2007) retained. Marine mammal hearing groups and their 
associated hearing ranges are provided in table 2.

                  Table 2--Marine Mammal Hearing Groups
                              [NMFS, 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen   7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 Cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65-dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the USAF's construction 
activities have the potential to result in behavioral harassment of 
marine mammals in the vicinity of the project area. The notice of 
proposed IHA (88 FR 74451, October 31, 2023) included a discussion of 
the effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from the USAF's construction on marine 
mammals and their habitat. That information and analysis is 
incorporated by reference into this final IHA determination and is not 
repeated here; please refer to the notice of proposed IHA (88 FR 74451, 
October 31, 2023).

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform both NMFS' consideration 
of ``small numbers,'' and the negligible impact determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which: (i) has the potential to injure 
a marine mammal or marine mammal stock in the wild (Level A 
harassment); or (ii) has the potential to disturb a marine mammal or 
marine mammal stock in the wild by causing disruption of behavioral 
patterns, including, but not limited to, migration, breathing, nursing, 
breeding, feeding, or sheltering (Level B harassment).
    Authorized takes would primarily be by Level B harassment, as use 
of the acoustic sources (i.e., impact and vibratory pile driving and 
removal and DTH) has the potential to result in disruption of 
behavioral patterns for individual marine mammals. There is also some 
potential for auditory injury (Level A harassment) to result, primarily 
for mysticetes and/or high frequency species and/or phocids because 
predicted auditory injury zones are larger than for mid-frequency 
species and/or otariids. Auditory injury is unlikely to occur for other 
groups. The required mitigation and monitoring measures are expected to 
minimize the severity of the taking to the extent practicable.
    As described previously, no serious injury or mortality is 
anticipated or 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 how take is estimated.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007; 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

[[Page 17427]]

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 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. 
USAF's planned activity includes the use of continuous (vibratory pile 
driving and removal and DTH) and impulsive (impact pile driving and 
DTH) sources, and therefore the RMS SPL thresholds of 120 and 160 dB re 
1 [mu]Pa is/are applicable.
    Level A Harassment--NMFS' ``Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing'' (Version 2.0, 
Technical Guidance, 2018) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). USAF's 
planned activity includes the use of impulsive (impact pile driving and 
DTH) and non-impulsive (vibratory pile driving and removal and DTH) 
sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS' 2018 Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                     PTS onset acoustic thresholds * (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) Underwater)......  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has
  a reference value of 1[mu]Pa\2\s. In this table, thresholds are abbreviated to reflect American National
  Standards Institute standards (ANSI, 2013). However, peak sound pressure is defined by ANSI as incorporating
  frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is
  being included to indicate peak sound pressure should be flat weighted or unweighted within the generalized
  hearing range. The subscript associated with cumulative sound exposure level thresholds indicates the
  designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds) and
  that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be
  exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible, it
  is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the planned project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., pile driving and removal and 
DTH). The maximum (underwater) area ensonified above the thresholds for 
behavioral harassment referenced above is 1286 kilometers\2\ (km\2\) 
(496 miles\2\ (mi\2\)), and the calculated distance to the farthest 
behavioral harassment isopleth is approximately 39,811 meters (m) 
(24,737.4 mi).
    The project includes vibratory pile installation and removal, 
impact pile driving, and DTH. Source levels for these activities are 
based on reviews of measurements of the same or similar types and 
dimensions of piles available in the literature. Source levels for each 
pile size and activity are presented in table 4. Source levels for 
vibratory installation and removal of piles of the same diameter are 
assumed to be the same.
    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 recommends proxy levels for Level A 
harassment based on available data regarding DTH systems of similar 
sized piles and holes (Denes et al., 2019; Reyff and Heyvaert, 2019; 
Reyff, 2020; Heyvaert and Reyff, 2021) (table 4 includes sound pressure 
and sound exposure levels for each pile type).

[[Page 17428]]



Table 4--Estimates of Mean Underwater Sound Levels Generated During Vibratory and Impact Pile Installation, DTH,
                                           and Vibratory Pile Removal
----------------------------------------------------------------------------------------------------------------
                                                 SSL at 10 m dB
           Continuous sound sources                   rms                       Literature source
----------------------------------------------------------------------------------------------------------------
                                                Vibratory Hammer
----------------------------------------------------------------------------------------------------------------
42-in steel piles.............................            168.2  Port of Anchorage Test Pile Program (table 16
                                                                  in Austin et al., 2016).
30-in steel piles.............................              166  * NMFS Analysis (C. Hotchkin, April 24, 2023).
----------------------------------------------------------------------------------------------------------------
                                                       DTH
----------------------------------------------------------------------------------------------------------------
42-in steel piles.............................              174  Reyff & Heyvaert, 2019; Reyff, 2020.
30-in steel piles.............................              174  Reyff & Heyvaert, 2019; Reyff, 2020.
----------------------------------------------------------------------------------------------------------------


 
 
----------------------------------------------------------------------------------------------------------------
Impulsive sound sources                          dB rms       dB SEL      dB peak  Literature source
----------------------------------------------------------------------------------------------------------------
                                                  Impact Hammer
----------------------------------------------------------------------------------------------------------------
42-in steel piles.........................          192          179          213  Caltrans, 2020.
30-in steel piles.........................          191          177          212  Caltrans, 2020.
----------------------------------------------------------------------------------------------------------------
                                                       DTH
----------------------------------------------------------------------------------------------------------------
42-in steel piles.........................          N/A          164          194  Reyff & Heyvaert, 2019;
                                                                                    Reyff, 2020; Denes et al.,
                                                                                    2019.
30-in steel piles.........................          N/A          164          194  Reyff & Heyvaert, 2019;
                                                                                    Reyff, 2020; Denes et al.,
                                                                                    2019.
----------------------------------------------------------------------------------------------------------------
Note: dB peak = peak sound level; DTH = down-the-hole drilling; rms = root mean square; SEL = sound exposure
  level.
* NMFS generated this source level by completing a completed a comprehensive review of source levels relevant to
  southeast Alaska; NMFS compiled all available data from Puget Sound and southeast Alaska and adjusted the data
  to standardize distance from the measured pile to 10 m. NMFS then calculated average source levels for each
  project and for each pile type. NMFS weighted impact pile driving project averages by the number of strikes
  per pile following the methodology in Navy (2015).

    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * Log10 (R1/R2),

Where

TL = transmission loss in dB
B = transmission loss coefficient
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    Absent site-specific acoustical monitoring with differing measured 
transmission loss, a practical spreading value of 15 is used as the 
transmission loss coefficient in the above formula. Site-specific 
transmission loss data for the Shemya Island are not available; 
therefore, the default coefficient of 15 is used to determine the 
distances to the Level A harassment and Level B harassment thresholds.
    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources such as pile driving, the optional User Spreadsheet 
tool predicts the distance at which, if a marine mammal remained at 
that distance for the duration of the activity, it would be expected to 
incur PTS. Inputs used in the optional User Spreadsheet tool, and the 
resulting estimated isopleths, are reported below.

                                                                                Table 5--User Spreadsheet Inputs
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Vibratory                                              Impact                                                  DTH
                               -----------------------------------------------------------------------------------------------------------------------------------------------------------------
                                    30-in steel piles          42-in steel piles          30-in steel piles          42-in steel piles          30-in steel piles          42-in steel piles
                               -----------------------------------------------------------------------------------------------------------------------------------------------------------------
                                 Installation or removal          Installation               Installation               Installation               Installation               Installation
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used..........  A.1) Vibratory Pile        A.1) Vibratory Pile        E.1) Impact Pile Driving.  E.1) Impact Pile Driving.  E.2) DTH Pile Driving....  E.2) DTH Pile Driving.
                                 Driving.                   Driving.
Source Level (SPL)............  166 RMS..................  168.2 RMS................  177 SEL..................  179 SEL..................  174 RMS, 164 SEL.........  174 RMS, 164 SEL.
Transmission Loss Coefficient.  15.......................  15.......................  15.......................  15.......................  15.......................  15
Weighting Factor Adjustment     2.5......................  2.5......................  2........................  2........................  2........................  2
 (kHz).

[[Page 17429]]

 
Activity Duration per day       60.......................  120......................  120......................  180......................  150......................  180
 (minutes).
Strike Rate per second........  .........................  .........................  .........................  .........................  10.......................  10
Number of strikes per pile....  .........................  .........................  900......................  1,800....................  .........................  .........................
Number of piles per day.......  4........................  4........................  4........................  4........................  3........................  3
Distance of sound pressure      10.......................  10.......................  10.......................  10.......................  10.......................  10
 level measurement.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


   Table 6--Level A Harassment and Level B Harassment Isopleths From Vibratory and Impact Pile Driving and DTH
----------------------------------------------------------------------------------------------------------------
                                                    Level A harassment isopleths (m)                   Level B
                                   -----------------------------------------------------------------  harassment
             Pile type                                                                                 isopleth
                                         LF           MF           HF           PW           OW          (m)
----------------------------------------------------------------------------------------------------------------
                                                    Vibratory
----------------------------------------------------------------------------------------------------------------
42-in steel pipe piles............         32.7          2.9         48.4         19.9          1.4       16,343
30-in Steel pipe piles............         14.7          1.3         21.8          8.9          0.6       11,659
----------------------------------------------------------------------------------------------------------------
                                                       DTH
----------------------------------------------------------------------------------------------------------------
42-in Steel pipe piles............      2,549.4         90.7      3,036.7      1,364.3         99.3       39,811
30-in Steel pipe piles............      2,257.6         80.3      2,689.2      1,208.2           88       39,811
----------------------------------------------------------------------------------------------------------------
                                                     Impact
----------------------------------------------------------------------------------------------------------------
42-in steel pipe piles............      2,015.1         71.7      2,400.3      1,078.4         78.5        1,359
30-in Steel pipe piles............        933.8         33.2      1,112.3        499.7         36.4        1,166
----------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence and Take Estimation

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations. We describe how the information 
provided is synthesized to produce a quantitative take estimate.
    As described above, for some species (humpback whale, killer whale, 
Steller sea lion and harbor seal) observations within the project area 
from the prior monitoring were available to directly inform the take 
estimates, while for other species (fin whale, minke whale, sperm 
whale, Baird's beaked whale, Stejneger's beaked whale, Dall's porpoise, 
harbor porpoise and northern fur seal) they were not. Prior surveys 
include Protected Species Observer (PSO) monitoring completed at the 
project site on 60 days between June and August 2021 during the 
emergency fuel pier repair, island-wide faunal surveys completed by the 
USACE Engineer Research Development Center (ERDC) across 33 days 
between 2016 and 2019 (primarily in the spring and fall), and island-
wide marine mammal surveys completed by the USACE Civil Works 
Environmental Resource Section on 26 days between May and October 2021. 
From all three surveys, data that were collected within the project 
area are primarily the basis for the take estimates because those data 
best represents what might be encountered there. Average group sizes 
used to inform Level B take estimates (which also underlie the 
estimates for Level A harassment) for all species with prior 
observations in the project area are primarily based on those data. 
Alternate methods utilizing average group sizes informed primarily by 
Alaska's Wildlife Notebook Series are used for species without prior 
observations.
    Also of note, while the results are not significantly different, in 
some cases we recommended modified methods for estimating take from 
those presented by the applicant and have described them below. A 
summary of authorized take, including as a percentage of population for 
each of the species, is shown in table 7.

Fin Whale

    No fin whale were reported during monitoring conducted for the EAS 
fuel pier emergency repair completed in 2021, nor during other surveys 
completed from Shemya Island (see application). Accordingly, average 
group size, estimated group size based on information shared in the 
Alaska Wildlife Notebook Series (Clark, 2008a), is used as the basis 
for the take estimates.
    USAF requested 17 takes of fin whales by Level B harassment, using 
a calculation based on 0.002 groups of eight fin whales per hour of 
construction activity. NMFS concurs with USAF's predicted group size of 
fin whale (eight individuals), but since there are no observations of 
this species from Shemya Island, NMFS finds it more appropriate to 
estimate take by Level B harassment using a less granular occurrence 
estimate (monthly) rather than USAF's hourly occurrence

[[Page 17430]]

estimate. Specifically, one group of eight fin whales is predicted 
every 2 construction months, based on the applicant's prediction that 
this species would be rare in the project area. The duration of the 
construction is 160 days (2.65 * the basic 60-day period) and 8 * 2.65 
= 21 takes by Level B harassment).
    Although the shutdown zone is larger than the Level A harassment 
zone for low frequency cetaceans, USAF indicates that at >=2,000 m, it 
becomes more challenging to reliably detect low frequency cetaceans in 
some environmental conditions, and therefore it is possible that a fin 
whale could enter the Level A harassment zone during DTH activities and 
stay long enough to incur PTS before USAF detects the animal and shuts 
down. As such, USAF requested and NMFS authorized a small amount of 
take by Level A harassment of fin whales. NMFS calculated takes by 
Level A harassment by first determining the proportion of the area of 
largest Level A harassment zone (42-in DTH, 2,549 m) that occurs beyond 
the readily observable 2,000 m from the pile driving location (i.e., 
7.5 km\2\-5 km\2\/7.5 km\2\ = 0.33). This ratio was multiplied by the 
estimated fin whale exposures, which is generally one group of eight 
fin whale that would occur every 2 construction months (or 60 days, 
adjusted by 1.2 to account for the 70 days that DTH activities are 
planned). Multiplying these factors (8 * 1.2 * 0.33) results in three 
takes by Level A harassment.
    Any individuals exposed to the higher levels associated with the 
potential for PTS closer to the source might also be behaviorally 
disturbed, however, for the purposes of quantifying take we do not 
count those exposures of one individual as both a Level A harassment 
take and a Level B harassment take, and therefore takes by Level B 
harassment calculated as described above are further modified to deduct 
the authorized amount of take by Level A harassment (i.e., 21-3 = 18).
    Therefore, NMFS proposes to authorize 3 takes by Level A harassment 
and 18 takes by Level B harassment for fin whales, for a total of 21 
takes.

Humpback Whale

    Across 119 days of marine mammal surveys completed from Shemya 
Island between 2016 and 2021, seven humpback whales were observed in 
the project area. The average group size for humpback whales detected 
in the project area was two humpback whales per group detected.
    For estimating take by Level B harassment where monitoring data 
confirmed the presence of the marine mammal species, NMFS concurred 
with USAF's approach. USAF requested take by Level B harassment by 
predicting that 0.07 groups of humpback whales would be sighted every 
hour, which was based on the applicant predicting this species would 
commonly occur within the project area. This was then multiplied by the 
average group size for humpback whales (two individuals), to achieve an 
hourly humpback rate. Finally, these numbers are multiplied by the 
hours of construction activity (0.07 * 2 * 1,101 = 154 takes by Level B 
harassment).
    Although the shutdown zone is larger than the Level A harassment 
zone for low frequency cetaceans, USAF indicates that at >=2,000 m, it 
becomes more challenging to reliably detect low frequency cetaceans in 
some environmental conditions, and therefore it is possible that 
humpback whales could enter the Level A harassment zone during DTH 
activities and stay long enough to incur PTS before USAF detects the 
animal and shuts down. As such, USAF requested and NMFS authorized a 
small amount of take by Level A harassment of humpback whales. NMFS 
calculated takes by Level A harassment by determining the proportion of 
the area of largest Level A harassment zone (42-in DTH, 2,549 m) that 
occurs beyond 2,000 m from the pile driving location (i.e., 7.5 km\2\-5 
km\2\/7.5 km\2\ = 0.33) and multiplying this ratio by the estimated 
humpback whale exposures (0.07 groups of 2 humpback whale) that would 
occur every construction hour that DTH activities are planned (624 
hours) (0.07 * 2 * 624 * 0.33 = 29 takes by Level A harassment).
    For the reasons described above, takes by Level B harassment were 
modified to deduct the authorized amount of take by Level A harassment 
(i.e., 154-29 = 125).
    Therefore, NMFS proposes to authorize 29 takes by Level A 
harassment and 125 takes by Level B harassment for humpback whales, for 
a total of 154 takes.

Minke Whale

    No minke whales were reported during monitoring conducted for the 
EAS fuel pier emergency repair completed in 2021, nor during other 
surveys completed from Shemya Island (e.g., see application). 
Accordingly, average group size, estimated based on group size 
information shared in the Alaska Wildlife Notebook Series (Clark, 
2008a), is used as the basis for the take estimates (Guerrero, 2008b).
    USAF requested seven takes of minke whales by Level B harassment, 
using a calculation of 0.002 groups of three minke whales per hour of 
construction activity. NMFS concurs with USAF's predicted group size of 
minke whale (three individuals), but since there are no observations of 
this species from Shemya Island, NMFS finds it more appropriate to 
estimate take by Level B harassment using a less granular occurrence 
estimate (monthly) rather than USAF's hourly occurrence estimate. 
Specifically, one group of three minke whales is predicted every 2 
construction months, based on the applicant's prediction that this 
species would be rare in the project area. The duration of construction 
is 160 days (2.65 * the basic 60-day period, which corresponds to 2 
months) and 3 * 2.65 = 8 takes by Level B harassment.
    Although the shutdown zone is larger than the Level A harassment 
zone for low frequency cetaceans, USAF indicates that at >=2,000 m, it 
becomes more challenging to reliably detect low frequency cetaceans in 
some environmental conditions, and therefore it is possible that a 
minke whale could enter the Level A harassment zone during DTH 
activities and stay long enough to incur PTS before USAF detects the 
animal and shuts down. As such, USAF requested and NMFS authorized a 
small amount of take by Level A harassment of minke whales. NMFS 
calculated takes by Level A harassment by determining the proportion of 
the area of largest Level A harassment zone (42-in DTH, 2,549 m) that 
occurs beyond the readily observable 2,000 m from the pile driving 
location (i.e., 7.5 km\2\-5 km\2\/7.5 km\2\ = 0.33).This ratio was 
multiplied by the estimated minke whale exposures, which is generally 
one group of three minke whales every 2 construction months (or 60 
days), adjusted by 1.2 to account for the 70 days that DTH activities 
are planned. Multiplying these factors (1.2 * 0.33) results in one take 
by Level A harassment. Since the predicted average group size of minke 
whale is three, NMFS proposes to authorize three takes by Level A 
harassment of minke whale.
    For reasons described above, takes by Level B harassment were 
modified to deduct the authorized amount of take by Level A harassment 
(i.e., 8-3 = 5).
    Therefore, NMFS proposes to authorize three takes by Level A 
harassment and five takes by Level B harassment for minke whales, for a 
total of eight takes.

Sperm Whale

    Across 119 monitoring days between 2016 and 2021, four sperm whales 
were observed on a single day from Shemya

[[Page 17431]]

Island, though outside of the project area (see application).
    USAF requested 27 takes of sperm whale by Level B harassment, using 
a calculation based on of 0.006 groups of four sperm whales per hour of 
construction activity. NMFS concurs with USAF's predicted group size of 
sperm whale (four individuals, which corresponds to the number of sperm 
whales detected on a single day during Shemya Island marine mammal 
surveys), but since there are few observations of this species from 
Shemya Island, NMFS finds it more appropriate to estimate take by Level 
B harassment using a less granular occurrence estimate (monthly) rather 
than USAF's hourly occurrence estimate. Specifically, two groups of 
four sperm whales is predicted every 1 construction month based on 
sperm whales being one of the most frequently sighted marine mammals in 
the high latitude regions of the North Pacific, including the Bering 
Sea and the Aleutian Islands. The duration of the construction is 5 
months and 2 * 4 * 5 = 40 takes by Level B harassment.
    Due to the small Level A harassment zones (table 8), which do not 
reach deep water where sperm whales are expected to be encountered, 
coupled with the implementation of shutdown zones, which will be larger 
than Level A harassment zones for mid-frequency cetaceans (described in 
the Mitigation section), NMFS concurs with USAF's assessment that take 
by Level A harassment is not anticipated for sperm whale. Therefore, 
NMFS authorized all 40 estimated exposures as takes by Level B 
harassment. Takes by Level A harassment for sperm whales are not 
requested nor are they authorized.

Baird's Beaked Whale

    Baird's beaked whales are usually found in tight social groups 
(schools or pods) averaging between 5 and 20 individuals, but they have 
occasionally been observed in larger groups of up to 50 animals. Across 
119 days of marine mammal surveys completed from Shemya Island between 
2016 and 2021, no observations of Baird's beaked whale were recorded 
(see application). Accordingly, average group size, estimated based on 
group size information shared in the Alaska Wildlife Notebook Series 
(Guerrero, 2008a), is used as the basis for take estimates.
    USAF requested 11 takes by Level B harassment, using a calculation 
based on 0.001 groups of ten Baird's beaked whales per hour of 
construction activity. NMFS concurs with USAF's predicted group size of 
Baird's beaked whale (10 individuals), but since there are no 
observations of this species from Shemya Island, NMFS finds it more 
appropriate to estimate take by Level B harassment using a less 
granular occurrence estimate (monthly) rather than USAF's hourly 
occurrence estimate. Specifically, 1 group of 10 Baird's beaked whales 
is predicted across the project, which is based on this species being 
shy and preferring deep waters and as such the applicant predicted they 
would be very rare in the project area. Therefore, NMFS proposes to 
authorize 10 takes of Baird's beaked whale by Level B harassment.
    Due to the small Level A harassment zones (table 8), which do not 
reach deep water where Baird's beaked whales are expected to be 
encountered, coupled with the implementation of shutdown zones, which 
will be larger than Level A harassment zones for mid-frequency 
cetaceans (described in the Mitigation section), NMFS concurs with 
USAF's assessment that take by Level A harassment is not anticipated 
for Baird's beaked whale. Therefore, NMFS authorized all 10 estimated 
exposures as takes by Level B harassment. Takes by Level A harassment 
for Baird's beaked whales are not requested nor are they authorized.

Stejneger's Beaked Whale

    Across 119 days of marine mammal surveys completed from Shemya 
Island between 2016 and 2021, no observations of Stejneger's beaked 
whale were recorded (see application). Accordingly, average group size, 
estimated based on group size information shared in the Alaska Wildlife 
Notebook Series (Guerrero, 2008a), is used as the basis for take 
estimates.
    USAF requested nine takes of Stejneger's beaked whale by Level B 
harassment, using a calculation based on of 0.001 groups of eight 
Stejneger's beaked whales per hour of construction activity. NMFS 
concurs with USAF's predicted group size of Stejneger's beaked whale 
(eight individuals), but since there are no observations of this 
species from Shemya Island, NMFS finds it more appropriate to estimate 
take by Level B harassment using a less granular occurrence estimate 
(monthly) rather than USAF's hourly occurrence estimate. Specifically, 
one group of eight Stejneger's beaked whales is predicted across the 
entirety of the project, based on this species being shy and preferring 
deep waters and as such the applicant predicted they would only be very 
rarely encountered in the project area. Therefore, NMFS proposes to 
authorize eight Stejneger's beaked whale by level B harassment.
    Due to the small Level A harassment zones (table 8), which do not 
reach deep water where Stejneger's beaked whales are expected to be 
encountered, coupled with the implementation of shutdown zones, which 
will be larger than Level A harassment zones for mid-frequency 
cetaceans (described in the Mitigation section), NMFS concurs with 
USAF's assessment that take by Level A harassment is not anticipated 
for Stejneger's beaked whale. Therefore, NMFS authorized all eight 
estimated exposures as takes by Level B harassment. Takes by Level A 
harassment for Stejneger's beaked whales are not requested nor are they 
authorized.

Killer Whale

    Across 119 days of marine mammal surveys completed from Shemya 
Island between 2016 and 2021, 69 killer whales were observed in the 
project area. The average group size for killer whales detected in the 
project area was eight killer whales per group detected.
    For estimating take by Level B harassment where monitoring data 
confirmed the presence of the marine mammal species, NMFS concurred 
with USAF's approach. USAF requested take by Level B harassment by 
predicting that 0.02 groups of killer whales would be sighted every 
hour, which was based on the applicant's prediction that this species 
would commonly be encountered in the project area. This was then 
multiplied by the average group size for humpback whales (eight 
individuals), to achieve an hourly killer whale rate. Finally, these 
numbers are multiplied by the hours of construction activity (0.02 * 8 
* 1,101 = 176 takes by Level B harassment).
    Due to the small Level A harassment zones (table 8), coupled with 
the implementation of shutdown zones, which will be larger than Level A 
harassment zones for mid-frequency cetaceans (described in the 
Mitigation section), NMFS concurs with USAF's assessment that take by 
Level A harassment is not anticipated for killer whale. Therefore, NMFS 
authorized all 176 estimated exposures as takes by Level B harassment. 
Takes by Level A harassment for killer whale are not requested nor are 
they authorized.

Dall's Porpoise

    No Dall's porpoise were reported during monitoring conducted for 
the EAS fuel pier emergency repair completed in 2021, nor during other 
surveys completed from Shemya Island (see application). Dall's porpoise 
generally travel in groups of 10 to 20 individuals but can occur in 
groups

[[Page 17432]]

with over hundreds of individuals (Wells, 2008). Accordingly, average 
group size, estimated based group size information shared in the Alaska 
Wildlife Notebook Series (Wells 2008), is used as the basis for the 
take estimates, is used as the basis for take estimates.
    USAF requested 33 takes of Dall's porpoise by Level B harassment, 
using a calculation based on of 0.002 groups of 15 Dall's porpoise per 
hour of construction activity. NMFS concurs with USAF's predicted group 
size of Dall's porpoise (15 individuals), but since there are no 
observations of this species from Shemya Island, NMFS finds it more 
appropriate to estimate take by Level B harassment using a less 
granular occurrence estimate (monthly) rather than USAF's hourly 
occurrence estimate. Specifically, 1 group of 15 Dall's porpoise is 
predicted every 2 construction months, based on the applicant's 
prediction that this species would be rarely encountered in the project 
area. The duration of the construction is 160 days (2.65 * the basic 
60-day period that corresponds to 2 construction months) and 15 * 2.65 
= 40 takes by Level B harassment.
    For most activities, NMFS calculated takes by Level A harassment by 
determining the ratio of the largest Level A harassment area for 42-in 
DTH activities (i.e., 10.2 km\2\ for a Level A harassment distance of 
3,037 m) minus the area of the shutdown zone for Dall's porpoise (i.e., 
0.5 km\2\ for a shutdown zone distance of 500 m) to the area of the 
Level B harassment isopleth (1,285.9 km\2\) for a Level B harassment 
distance of 39,811 m (i.e., (10.2 km\2\-0.5 km\2\)/1,285.9 km\2\ = 
0.008). We then multiplied this ratio by the number of estimated Dall's 
porpoise exposures calculated as described above for Level B harassment 
to determine take by Level A harassment (i.e., 0.008 * 40 exposures = 
0.32 takes by Level A harassment).
    For Level A harassment during impact pile driving of 42-in piles, 
for which the Level A harassment zone is larger than the Level B 
harassment zone, NMFS estimates take based on 1 group of 15 Dall's 
porpoise every 2 months, or 60 days, in consideration of the 52 days 
(0.87 of 60) of impact driving of 42-in piles (15 Dall's porpoise * 
0.87 months = 13.05) for a total of 13.37 takes by Level A harassment 
(0.32 + 13.05 = 13).
    For reasons described above, takes by Level B harassment were 
modified to deduct the authorized amount of take by Level A harassment 
(i.e., 40-13 = 27).
    Therefore, NMFS proposes to authorize 13 takes by Level A 
harassment and 27 takes by Level B harassment for Dall's porpoise, for 
a total of 40 takes.

Harbor Porpoise

    Across 119 monitoring days between 2016 and 2021, one group of two 
to three harbor porpoise were observed from Shemya Island (see 
application), though outside of the project area. Average group size, 
estimated based on the Alaska Wildlife Notebook Series (Schmale, 2008), 
is used as the basis for take estimates.
    USAF requested 11 takes of harbor porpoise by Level B harassment, 
using a calculation based on of 0.01 groups of 1 harbor porpoise per 
hour of construction activity. NMFS concurs with USAF's predicted group 
size of harbor porpoise (one individual), but since there are few 
observations of this species from Shemya Island, NMFS finds it more 
appropriate to estimate take by Level B harassment using a less 
granular occurrence estimate (monthly) rather than USAF's hourly 
occurrence estimate. Specifically, three groups of one harbor porpoise 
is predicted every 1 construction month. The duration of construction 
is 5 months and 3 * 5 = 15 takes by Level B harassment.
    For most activities, NMFS calculated takes by Level A harassment by 
determining the ratio of the largest Level A harassment area for 42-in 
DTH activities (i.e., 10.2 km\2\ for a Level A harassment distance of 
3,037 m) minus the area of the shutdown zone for harbor porpoise (i.e., 
0.5 km\2\ for a shutdown zone distance of 500 m) to the area of the 
Level B harassment isopleth (1,285.9 km\2\) for a Level B harassment 
distance of 39,811 m (i.e., (10.2 km\2\-0.5 km\2\)/1,285.9 km\2\ = 
0.008). We then multiplied this ratio by the number of estimated harbor 
porpoise exposures calculated as described above for Level B harassment 
to determine take by Level A harassment (i.e., 0.008 * 15 exposures = 
0.12 takes by Level A harassment).
    For Level A harassment during impact pile driving of 42-in piles, 
for which the Level A harassment zone is larger than the Level B 
harassment zone, NMFS estimates take based on three groups of one 
harbor porpoise could be taken by Level A harassment every 1 month, or 
30 days in consideration of the 52 days (1.7 * 30) of impact pile 
driving of 42-in piles (3 groups of 1 harbor porpoise * 1.7 = 5.1) for 
a total of five takes by Level A harassment (0.12 + 5.1 = 5).
    For reasons described above, takes by Level B harassment were 
modified to deduct the authorized amount of take by Level A harassment 
(i.e., 15-5 = 10).
    Therefore, NMFS proposes to authorize 5 takes by Level A harassment 
and 10 takes by Level B harassment for harbor porpoise, for a total of 
15 takes.

Northern Fur Seal

    USAF requested 33 takes of northern fur seal by Level B harassment 
using a calculation based on 0.003 groups of eight northern fur seals 
per hour of construction activity. NMFS disagrees with USAF's predicted 
group size of northern fur seal, as these animals are typically 
solitary when at sea. Additionally, because there are no records of 
northern fur seal in the area, NMFS finds it more appropriate to 
estimate take by Level B harassment according to a less granular 
occurrence estimate (monthly) rather than USAF's hourly occurrence 
estimate. Specifically, one group of one northern fur seal every 1 
construction month is predicted and 1 * 5 = 5 takes by Level B 
harassment.
    Due to the small Level A harassment zones (table 8), coupled with 
the implementation of shutdown zones, which will be larger than Level A 
harassment zones for otariids (described in the Mitigation section), 
NMFS concurs with USAF's assessment that take by Level A harassment is 
not anticipated for northern fur seal. Therefore, NMFS authorized all 
five estimated exposures as takes by Level B harassment. Takes by Level 
A harassment for northern fur seals are not requested nor are they 
authorized.

Steller Sea Lion

    Steller sea lions are frequently observed around Shemya Island 
outside of the ensonified area, but only occasionally observed in Alcan 
Harbor and Shemya Pass (see application). Across 119 monitoring days 
between 2016 and 2021, 16 Steller sea lions were observed within the 
project area. The average group size for Steller sea lion detected in 
the project area as well as around Shemya Island was one Steller sea 
lion per detection.
    For estimating take by Level B harassment where monitoring data 
confirmed the presence of the marine mammal species, NMFS concurred 
with USAF's planned approach. USAF requested take by Level B harassment 
by predicting that 0.09 groups of Steller sea lion would be sighted 
every hour, which was based on the applicant's prediction that this 
species would be more commonly encountered in the project area. This 
was then multiplied by the average group size for Steller sea lion (1 
individual), to achieve an hourly steller sea lion rate. Finally, these 
numbers are multiplied by the hours of construction activity (0.09 * 1 
* 1,101 = 99 takes by Level B harassment).

[[Page 17433]]

    Due to the small Level A harassment zones (table 8), coupled with 
the implementation of shutdown zones, which will be larger than Level A 
harassment zones for otariids (described in the Mitigation section), 
NMFS concurs with USAF's assessment that take by Level A harassment is 
not anticipated for Steller sea lion. Therefore, NMFS authorized all 99 
estimated exposures as takes by Level B harassment. Takes by Level A 
harassment for Steller sea lion are not requested nor are they 
authorized.

Harbor Seal

    Across 119 monitoring days between 2016 and 2021, 54 harbor seals 
were observed within the project area. The average group size for 
harbor seals detected in the project area was one harbor seals per 
group.
    For estimating take by Level B harassment where monitoring data 
confirmed the presence of the marine mammal species, NMFS concurred 
with USAF's planned approach. USAF requested take by Level B harassment 
by predicting that 0.14 groups of harbor seals would be sighted every 
hour, which was based on the fact that this species is expected to more 
commonly occur within the project area. This was then multiplied by the 
average group size for harbor seal (1 individual), to achieve an hourly 
harbor seal rate. Finally, these numbers are multiplied by the hours of 
construction activity (0.14 * 1 * 1,101 = 154 takes by Level B 
harassment).
    NMFS initially calculated takes by Level A harassment by 
determining the ratio of the largest Level A harassment area for 42-in 
DTH activities (i.e., 2.6 km\2\ for a Level A harassment distance of 
1364 m) minus the area of the shutdown zone for harbor seal (i.e., 0.37 
km\2\ for a shutdown zone distance of 400 m) to the area of the Level B 
harassment isopleth (1,285.9 km\2\) for a Level B harassment distance 
of 39,811 m (i.e., (2.6 km\2\-0.37 km\2\)/1,285.9 km\2\ = 0.002). We 
then multiplied this ratio by the number of estimated harbor seal 
exposures calculated as described above for Level B harassment to 
determine take by Level A harassment (i.e., 0.002 * 154 exposures = 0.3 
takes by Level A harassment).
    Because harbor seals typically inhabit areas closer to shore rather 
than distances represented by the largest level B zone (39,811 m), NMFS 
determined that the method above could underestimate potential take by 
Level A harassment. NMFS accordingly estimated additional takes by 
Level A harassment by determining the ratio of harbor seals that were 
observed beyond the shutdown zone isopleth compared to the harbor seals 
that were observed closer to construction activities during the EAS 
fuel pier emergency repair that was completed in 2021 (i.e., 11/38 = 
0.29 harbor seals). We then multiplied this ratio by the total number 
of estimated harbor seal exposures to determine take by Level A 
harassment (i.e., 0.29 * 154 exposures = 45) for a total of 45 takes by 
Level A harassment (0.3 + 45 = 45.3).
    For reasons described above, takes by Level B harassment were 
modified to deduct the authorized amount of take by Level A harassment 
(i.e., 154-45 = 109).
    Therefore, NMFS proposes to authorize 45 takes by Level A 
harassment and 109 takes by Level B harassment for harbor seal, for a 
total of 154 takes.

          Table 7--Authorized Take by Stock and Harassment Type and as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
                                                                                Authorized take       Authorized
                                                                          --------------------------  take as a
                  Species                               Stock                                         percentage
                                                                             Level B      Level A      of stock
                                                                            harassment   harassment   abundance
----------------------------------------------------------------------------------------------------------------
Fin Whale.................................  Northeast Pacific............           18            3           <1
Humpback Whale............................  Western North Pacific........            3            1           <1
                                            Mexico--North Pacific........            9            2          1.2
                                            Hawai[revaps]i...............          113           26          1.2
Minke Whale...............................  Alaska.......................            5            3           <1
Sperm Whale...............................  North Pacific................           40            0         16.4
Baird's beaked whale......................  Alaska.......................           10            0          (*)
Stejneger's beaked whale..................  Alaska.......................            8            0          (*)
Killer whale..............................  ENP Alaska Resident Stock....          176            0          9.2
                                            ENP Gulf of Alaska, Aleutian                                      30
                                             Islands, and Bering Seal.
Dall's Porpoise...........................  Alaska.......................           26           13           <1
Harbor Porpoise...........................  Bering Seal..................           10            5           <1
Northern Fur Seal.........................  Eastern Pacific..............            5            0           <1
Steller Sea Lion..........................  Western, U.S.................           99            0           <1
Harbor Seal...............................  Aleutian Islands.............          109           45          2.8
----------------------------------------------------------------------------------------------------------------
* Reliable abundance estimates for these stock are currently unavailable.

Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to the 
activity, and other means of effecting the least practicable impact on 
the species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks, and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, NMFS 
considers two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat, as 
well as subsistence uses. This considers the nature of the potential 
adverse impact being mitigated (likelihood, scope,

[[Page 17434]]

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.
    USAF must ensure that construction supervisors and crews, the 
monitoring team and relevant USAF 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.

Mitigation for Marine Mammals and Their Habitat

    Shutdown Zones--For all pile driving/removal and DTH activities, 
USAF would implement shutdowns within designated zones. 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 
vary based on the activity type and marine mammal hearing group (table 
8). In most cases, the shutdown zones are based on the estimated Level 
A harassment isopleth distances for each hearing group, as requested by 
USAF. However, in cases where it would be challenging to detect marine 
mammals at the Level A isopleth, (e.g., for high frequency cetaceans 
and phocids during DTH activities and impact pile driving), smaller 
shutdown zones have been established (table 8). Additionally, USAF has 
agreed to implement a minimum shutdown zone of 25 m during all pile 
driving and removal activities and DTH.
    Finally, construction supervisors and crews, PSOs, and relevant 
USAF staff must avoid direct physical interaction with marine mammals 
during construction activity. If a marine mammal comes within 10 m of 
such activity, operations must cease and vessels must reduce speed to 
the minimum level required to maintain steerage and safe working 
conditions, as necessary to avoid direct physical interaction. If an 
activity 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 
indicated in table 8 or 15 minutes have passed for delphinids or 
pinnipeds or 30 minutes for all other species without re-detection of 
the animal.
    Construction activities must be halted upon observation of a 
species for which incidental take is not authorized or a species for 
which incidental take has been authorized but the authorized number of 
takes has been met entering or within the harassment zone.

                                                                 Table 8--Shutdown Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                Shutdown zones (m)
                    Activity                                  Pile diameter             ----------------------------------------------------------------
                                                                                              LF           MF           HF           PW           OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Installation or Removal...............  42-in................................                                 50
                                                 -------------------------------------------------------------------------------------------------------
                                                  30-in................................                                 25
--------------------------------------------------------------------------------------------------------------------------------------------------------
DTH.............................................  42-in................................        2,600          100          500          400          100
                                                  30-in................................        2,300           80                                     90
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile.....................................  42-in................................        2,100                                                  80
                                                  30-in................................        1,000           50                                     50
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Protected Species Observers--The number and placement of PSOs 
during all construction activities (described in the Monitoring and 
Reporting section) would ensure that the entire shutdown zone is 
visible. USAF would employ at least two PSOs for all pile driving and 
DTH activities.
    Monitoring for Level B Harassment--PSOs would monitor the shutdown 
zones and beyond to the extent that PSOs can see. Monitoring beyond the 
shutdown zones enables 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. If a marine mammal enters the Level B 
harassment zone, PSOs will document the marine mammal's presence and 
behavior.
    Pre and Post-Activity Monitoring--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, Level A 
harassment, and Level B harassment for a period of 30 minutes. Pre-
start clearance monitoring must be conducted during periods of 
visibility sufficient for the lead PSO to determine that the shutdown 
zones are clear of marine mammals. If the shutdown zone is obscured by 
fog or poor lighting conditions, in-water construction activity will 
not be initiated until the entire shutdown zone is visible. Pile 
driving may commence following 30 minutes of observation when the 
determination is made that the shutdown zones are clear of marine 
mammals. If a marine mammal is observed entering or within shutdown 
zones, pile driving activity must be delayed or halted. If pile driving 
is delayed or halted due to the presence of a marine mammal, the 
activity may not commence or resume until either the animal has 
voluntarily exited and been visually confirmed beyond the shutdown zone 
or 15 minutes have passed for delphinids or pinnipeds or 30 minutes 
have passed for all other species without re-detection of the animal. 
If a marine mammal for which Level B harassment take is authorized is 
present in the Level B harassment zone, activities would begin and 
Level B harassment take would be recorded.
    Soft Start--The use of soft-start procedures are believed to 
provide additional protection to marine mammals by providing warning 
and/or giving marine mammals a chance to leave the area prior to the 
hammer operating at full capacity. For impact pile driving, contractors 
would be required to provide an initial set of three strikes from the 
hammer at reduced energy, with each strike followed by a 30-second 
waiting period. This

[[Page 17435]]

procedure would be conducted a total of three times before impact pile 
driving begins. Soft start would be implemented at the start of each 
day's impact pile driving and at any time following cessation of impact 
pile driving for a period of 30 minutes or longer. Soft start is not 
required during vibratory pile driving and removal activities.
    Based on our evaluation of the applicant's planned measures, as 
well as other measures considered by NMFS, 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:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and,
     Mitigation and monitoring effectiveness.
    Visual Monitoring--Marine mammal monitoring must be conducted in 
accordance with the Marine Mammal Monitoring and Mitigation Plan. 
Marine mammal monitoring during pile driving and removal and DTH 
activities must be conducted by NMFS-approved PSOs in a manner 
consistent with the following:
     PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor), and have no other assigned tasks 
during monitoring periods;
     At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
     Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field) or training 
for experience performing the duties of a PSO during construction 
activities pursuant to a NMFS-issued incidental take authorization.
     Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator will be designated. The lead 
observer will be required to have prior experience working as a marine 
mammal observer during construction activity pursuant to a NMFS-issued 
incidental take authorization; and,
     PSOs must be approved by NMFS prior to beginning any 
activity subject to this IHA.
    PSOs must also have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including, but not limited to, the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was note implemented when required); 
and marine mammal behavior; and,
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    Visual monitoring will be conducted by a minimum of two trained 
PSOs positioned at suitable vantage points. One PSO will have an 
unobstructed view of all water within the shutdown zone and will be 
stationed at or near the pier. Remaining PSOs will be placed at one or 
more of the observer monitoring locations identified on figure 3-3 of 
the marine mammal monitoring and mitigation plan, in order to observe 
as much as the Level A and Level B harassment zone as possible. All 
PSOs will have access to 20 by 60 spotting scope on a window mount or 
tripod.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after all in water construction activities. In addition, PSOs 
will record all incidents of marine mammal occurrence, regardless of 
distance from activity, and will 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

    USAF will submit a draft marine mammal monitoring report to NMFS 
within 90 days after the completion of pile driving activities, or 60 
days prior to a requested date of issuance of any future IHAs for the 
project, or other projects at the same location, whichever comes first. 
The marine mammal monitoring report will include an overall description 
of work completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report will include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including: (1) The number and type of piles that 
were driven and the method (e.g., impact, vibratory, DTH); (2) Total 
duration of driving time for each pile (vibratory driving) and number 
of strikes for each pile (impact driving); and (3) For DTH drilling, 
duration of operation for both impulsive and non-pulse components;
     PSO locations during marine mammal monitoring;
     Environmental conditions during monitoring periods (at 
beginning and

[[Page 17436]]

end of PSO shift and whenever conditions change significantly), 
including Beaufort sea state and any other relevant weather conditions 
including cloud cover, fog, sun glare, and overall visibility to the 
horizon, and estimated observable distance;
     Upon observation of a marine mammal, the following 
information: (1) Name of PSO who sighted the animal(s) and PSO location 
and activity at time of sighting; (2) Time of sighting; (3) 
Identification of the animal(s) (e.g., genus/species, lowest possible 
taxonomic level, or unidentified), PSO confidence in identification, 
and the composition of the group if there is a mix of species; (4) 
Distance and location of each observed marine mammal relative to the 
pile being driven for each sighting; (5) Estimated number of animals 
(min/max/best estimate); (6) Estimated number of animals by cohort 
(adults, juveniles, neonates, group composition, etc.); (7) Animal's 
closest point of approach and estimated time spent within the 
harassment zone; (8) Description of any marine mammal behavioral 
observations (e.g., observed behaviors such as feeding or traveling), 
including an assessment of behavioral responses thought to have 
resulted from the activity (e.g., no response or changes in behavioral 
state such as ceasing feeding, changing direction, flushing, or 
breaching);
     Number of marine mammals detected within the harassment 
zones, by species; and,
     Detailed information about implementation of any 
mitigation (e.g., shutdowns and delays), a description of specific 
actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    A final report must be prepared and submitted within 30 calendar 
days following receipt of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 calendar days of receipt of 
the draft report, the report shall be considered final. All PSO 
datasheets and/or raw sighting data would be submitted with the draft 
marine mammal report.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the Holder must report the 
incident to the Office of Protected Resources (OPR), NMFS 
([email protected] and [email protected]) and to the 
Alaska regional stranding network (877-925-7773) as soon as feasible. 
If the death or injury was clearly caused by the specified activity, 
the Holder must immediately cease the activities until NMFS OPR 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 this IHA. The Holder must not resume their activities until notified 
by NMFS. The report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and,
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338, 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, the majority of our analysis applies to all 
the species listed in table 1, given that many of the anticipated 
effects of this project on different marine mammal stocks are expected 
to be relatively similar in nature. Where there are meaningful 
differences between species or stocks, or groups of species, in 
anticipated individual responses to activities, impact of expected take 
on the population due to differences in population status, or impacts 
on habitat, they are described independently in the analysis below.
    Pile driving and DTH activities associated with the EAS fuel pier 
repair project, as outlined previously, have the potential to disturb 
or displace marine mammals. Specifically, the specified activities may 
result in take, in the form of Level B harassment and, for some species 
Level A harassment, from underwater sounds generated by pile driving 
and DTH. Potential takes could occur if marine mammals are present in 
zones ensonified above the thresholds for Level B harassment or Level A 
harassment, identified above, while activities are underway.
    No serious injury or mortality would be expected, even in the 
absence of required mitigation measures, given the nature of the 
activities. Further, no take by Level A harassment is anticipated for 
otariids and mid-frequency cetaceans, due to the application of planned 
mitigation measures, such as shutdown zones that encompass Level A 
harassment zones for these species. The potential for harassment would 
be minimized through the implementation of planned mitigation measures 
(see Mitigation section).
    Take by Level A harassment is authorized for six species (harbor 
porpoise, Dall's porpoise, harbor seal, fin whale, humpback whale, and 
minke whale) as the Level A harassment zone exceeds the size of the 
shutdown zones (high frequency cetaceans and phocids), or, in the case 
of low frequency cetaceans, the shutdown zone is so large that it is 
possible that a minke whale, fin whale, or humpback whale could enter 
the Level A harassment zone and remain within the zone for a duration 
long enough to incur PTS before being detected.
    Any take by Level A harassment is expected to arise from, at most, 
a small degree of PTS (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

[[Page 17437]]

than are expected to occur here in order to incur any more than a small 
degree of PTS.
    Given the small degree anticipated, any PTS potential incurred 
would not be expected to affect the reproductive success or survival of 
any individuals, much less result in adverse impacts on the species or 
stock.
    Additionally, some subset of the individuals that are behaviorally 
harassed could also simultaneously incur some small degree of TTS for a 
short duration of time. However, since the hearing sensitivity of 
individuals that incur TTS is expected to recover completely within 
minutes to hours, it is unlikely that the brief hearing impairment 
would affect the individual's long-term ability to forage and 
communicate with conspecifics, and would therefore not likely impact 
reproduction or survival of any individual marine mammal, let alone 
adversely affect rates of recruitment or survival of the species or 
stock.
    As described above, NMFS expects that marine mammals would likely 
move away from an aversive stimulus, especially at levels that would be 
expected to result in PTS, given sufficient notice through use of soft 
start. USAF would also shut down pile driving activities if marine 
mammals enter the shutdown zones (table 8) further minimizing the 
likelihood and degree of PTS that would be incurred.
    Effects on individuals that are taken by Level B harassment in the 
form of behavioral disruption, on the basis of reports in the 
literature as well as monitoring from other similar activities, would 
likely be limited to reactions such as avoidance, increased swimming 
speeds, increased surfacing time, or decreased foraging (if such 
activity were occurring) (e.g., Thorson and Reyff, 2006). Most likely, 
individuals would simply move away from the sound source and 
temporarily avoid the area where pile driving is occurring. If sound 
produced by project activities is sufficiently disturbing, animals are 
likely to simply avoid the area while the activities are occurring. We 
expect that any avoidance of the project areas by marine mammals would 
be temporary in nature and that any marine mammals that avoid the 
project areas during construction would not be permanently displaced. 
Short-term avoidance of the project areas and energetic impacts of 
interrupted foraging or other important behaviors is unlikely to affect 
the reproduction or survival of individual marine mammals, and the 
effects of behavioral disturbance on individuals is not likely to 
accrue in a manner that would affect the rates of recruitment or 
survival of any affected stock.
    The project area does overlap a Biologically Important Area (BIA) 
identified as important for feeding by sperm whale (Brower et al., 
2022). The BIA that overlaps the project area is active April through 
September, which overlaps USAF's planned work period (April to 
October). White the BIA is considered to be of higher importance, the 
area of the BIA is very large, spanning the island chain, and the 
project area is very small in comparison. Further sperm whales utilize 
deeper waters to feed, and while the Level B harassment zone does 
extend into deeper waters, the sound levels at the distances that 
overlay deeper water where sperm whales might be foraging would be of 
comparatively lower levels. Given the extensive options for high 
quality foraging area near and outside of the project area, any impacts 
to feeding sperm whales would not be expected to impact the survival or 
reproductive success of any individuals.
    The ensonified area also overlaps ESA-designated critical habitat 
for western DPS Steller sea lion. Specifically, the Level B ensonified 
area overlaps with the aquatic zones of three designated major haulouts 
to the east and northwest of the project site: Shemya Island Major 
Haulout, Alaid Island Major Haulout, Attu/Chirikof Point Major Haulout. 
The ensonified area Level B harassment zone related to implementation 
of the planned project, described in the Estimated Take of Marine 
Mammals section, overlaps with the designated aquatic zone of all three 
designated major haulouts.. No Steller sea lions have been observed on 
Shemya Island Major Haulout (2.75 nm to the east of the project site) 
during the most recent surveys (between 2015 and 2017) and only one 
Steller sea lion was observed at Attu/Chirikof Point Major Haulout (24 
nm northwest of the project site). An average of 68 non-pups and 7 pups 
were observed annually during this time at Alaid Island Major Haulout, 
which is 5 nautical miles northwest of the project site. The 
construction site itself does not overlap with critical habitat. Take 
by Level B harassment of steller sea lions has been authorized to 
account for those that are occasionally observed in low numbers in 
Alcan Harbor and Shemya Pass, however, the project is not expected to 
have significant adverse impacts on Steller sea lion critical habitat.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The project activities 
would not modify existing marine mammal habitat for a significant 
amount of time. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range. We do not 
expect pile driving activities to have significant consequences to 
marine invertebrate populations. Given the short duration of the 
activities and the relatively small area of the habitat that may be 
affected, the impacts to marine mammal habitat, including fish and 
invertebrates, are not expected to cause significant or long-term 
negative consequences.
    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:
     No serious injury or mortality is anticipated or 
authorized;
     No Level A harassment of six species is authorized;
     Level A harassment takes authorized for six species are 
expected to be of a small degree;
     While impacts would occur within areas that are important 
for feeding for sperm whale, because of the small footprint of the 
activity relative to the area of these important use areas, we do not 
expect impacts to the reproduction and survival of any individuals;
     Effects on species that serve as prey for marine mammals 
from the activities are expected to be short-term and, therefore, any 
associated impacts on marine mammal feeding are not expected to result 
in significant or long-term consequences for individuals, or to accrue 
to adverse impacts on their populations;
     The lack of anticipated significant or long-term negative 
effects to marine mammal habitat; and,
     The efficacy of the mitigation measures in reducing the 
effects of the specified activities on all species and stocks.
    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 planned 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

[[Page 17438]]

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 instances of take NMFS proposes to authorize are below one-
third of the estimated stock abundance for all stocks (table 7). The 
number of animals that we expect to authorize to be taken from these 
stocks would be considered small relative to the relevant stocks' 
abundances even if each estimated taking occurred to a new individual, 
which is an unlikely scenario.
    The best available abundance estimate for fin whale is not 
considered representative of the entire stock as surveys were limited 
to a small portion of the stock's range, but there are known to be over 
2,500 fin whales in the northeast Pacific stock (Muto et al., 2021). As 
such, the 18 takes by Level B harassment and 3 takes by Level A 
harassment authorized, compared to the abundance estimate, shows that 
less than 1 percent of the stock would be expected to be impacted.
    The most recent abundance estimate for the Mexico-North Pacific 
stock of humpback whale is likely unreliable as it is more than 8 years 
old. The most relevant estimate of this stock's abundance in the Bering 
Sea and Aleutian Islands is 918 humpback whales (Wade, 2021), so the 9 
authorized takes by Level B harassment and 2 authorized takes by Level 
A harassment, is small relative to the estimated abundance (1.2 
percent), even if each authorized take occurred to a new individual.
    A lack of an accepted stock abundance value for the Alaska stock of 
minke whale did not allow for the calculation of an expected percentage 
of the population that would be affected. The most relevant estimate of 
partial stock abundance is 1,233 minke whales in coastal waters of the 
Alaska Peninsula and Aleutian Islands (Zerbini et al., 2006), so the 5 
authorized takes by Level B harassment, and 3 authorized takes by Level 
A harassment, compared to the abundance estimate, shows that less than 
1 percent of the stock would be expected to be impacted.
    The most recent abundance estimate for sperm whale in the North 
Pacific is likely unreliable as it is more than 8 years old and was 
derived from data collected in a small area that may not have included 
females and juveniles, and did not account for animals missed on the 
trackline. The minimum population estimate for this stock is 244 sperm 
whales, so the 40 authorized takes by Level B harassment is small 
relative to the estimated survey abundance, even if each authorized 
take occurred to a new individual.
    There is no abundance information available for any Alaskan stock 
of beaked whale. However, the take numbers are sufficiently small (8 
and 10 takes by Level B harassment for Stejneger's beaked whale and 
Baird's beaked whale, respectively) that we can safely assume that they 
are small relative to any reasonable assumption of likely population 
abundance for these stocks. For reference, current abundance estimates 
for other beaked whale stocks in the Pacific include 1,363 Baird's 
beaked whales (California/Oregon/Washington stock), 3,044 Mesoplodont 
beaked whales (CA/OR/WA stock), 5,454 Cuvier's beaked whales (CA/OR/WA 
stock), 564 Blainville's beaked whales (Hawai'i Pelagic stock), 2,550 
Longman's beaked whales (Hawai`i stock), and 3,180 Cuvier's beaked 
whales (Hawai'i Pelagic stock).
    The Alaska stock of Dall's porpoise has no official NMFS abundance 
estimate for this area, as the most recent estimate is greater than 8 
years old. The most recent estimate was 13,110 animals for just a 
portion of the stock's range. Therefore, the 26 takes by Level B 
harassment and 13 takes by Level A harassment authorized for this 
stock, compared to the abundance estimate, shows that less than 1 
percent of the stock would be expected to be impacted.
    For the Bering Sea stock of harbor porpoise, the most reliable 
abundance estimate is 5,713, a corrected estimate from a 2008 survey. 
However, this survey covered only a small portion of the stock's range, 
and therefore, is considered to be an underestimate for the entire 
stock (Muto et al., 2022). Given the 10 takes by Level B harassment 
authorized for the stock, and 5 takes by Level A harassment authorized 
for the stock, compared to the abundance estimate, which is only a 
portion of the Bering Sea Stock, shows that, at most, less than 1 
percent of the stock would be expected to be impacted.
    Based on the analysis contained herein of the planned 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.
    No subsistence hunting occurs on Shemya Island, which is a USAF Air 
Station; Access to the island is only provided by military aircraft and 
USAF-contracted charter planes for crews and workers. The nearest 
community that engages in subsistence hunting is located on Adak, 
Alaska which is 640 km (399 mi) to the east. Historically, an Alaska 
Native community on Attu, 60 km (37 mi) to the west, hunted for 
subsistence, but that community was destroyed during WWII and the 
residents that survived internment did not return to the island.
    Based on the description of the specified activity, NMFS has 
determined that there will not be an unmitigable adverse impact on 
subsistence uses from USAF's planned activities.

Endangered Species Act

    Section 7(a)(2) of the ESA (16 U.S.C. 1531 et seq.) requires that 
each Federal agency insure that any action it authorizes, funds, or 
carries out is not likely to jeopardize the continued existence of any 
endangered or threatened species or result in the destruction or 
adverse modification of designated critical habitat. To ensure ESA 
compliance for the issuance of IHAs, NMFS consults internally whenever 
we propose to authorize take for endangered or threatened species, in 
this case with the Alaska Regional Office.

[[Page 17439]]

    There are four marine mammal species (northeast Pacific fin whale, 
Mexico-North Pacific and western North Pacific humpback whale, North 
Pacific sperm whale, and western DPS Steller sea lion) with confirmed 
occurrence in the project area that are listed as endangered under the 
ESA. The NMFS Alaska Regional Office Protected Resources Division 
issued a Biological Opinion on March 1, 2024 under section 7 of the 
ESA, on the issuance of an IHA to USAF 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 northeast Pacific fin whale, Mexico Pacific 
and western North Pacific humpback whale, North Pacific sperm whale, 
and western DPS Steller sea lion and is not likely to destroy or 
adversely modify western DPS Steller sea lion critical habitat.

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 evaluate our proposed action (i.e., the issuance of an IHA) 
and alternatives 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 this IHA qualifies to be categorically excluded 
from further NEPA review.

Authorization

    NMFS has issued an IHA to USAF for the potential harassment of 
small numbers of 12 marine mammal species incidental to the Eareckson 
Air Station (EAS) Fuel Pier Repair in Alcan Harbor, Shemya Island, 
Alaska, that includes the previously explained mitigation, monitoring 
and reporting requirements.

    Dated: March 6, 2024.
Catherine G. Marzin,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2024-05105 Filed 3-8-24; 8:45 am]
BILLING CODE 3510-22-P