Notice2025-07168
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
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
April 25, 2025
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an incidental harassment authorization (IHA) to the United States Air Force Pacific Air Forces Regional Support Center (USAF) to incidentally harass marine mammals during construction activities associated with a the Eareckson Air Station (EAS) Fuel Pier Repair project in Alcan Harbor on Shemya Island, Alaska.
Full Text
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<title>Federal Register, Volume 90 Issue 79 (Friday, April 25, 2025)</title>
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[Federal Register Volume 90, Number 79 (Friday, April 25, 2025)]
[Notices]
[Pages 17410-17419]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-07168]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XE793]
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 United States Air Force Pacific Air Forces Regional Support Center
(USAF) to incidentally harass marine mammals during construction
activities associated with a the Eareckson Air Station (EAS) Fuel Pier
Repair project in Alcan Harbor on Shemya Island, Alaska.
DATES: This authorization is effective 1 year from the date of
issuance.
ADDRESSES: Electronic copies of the original application and supporting
documents, as well as a list of references cited in this document, may
be obtained online at: <a href="https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a>. In
case of problems accessing these documents, please call the contact
listed 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 monitoring and
reporting of the takings. The definitions of all applicable MMPA
statutory terms used above are included in the relevant sections below
and can be found in section 3 of the MMPA (16 U.S.C. 1362) and NMFS
regulations at 50 CFR 216.103.
History of Request
On May 15, 2023, NMFS received an application from U.S. Army Corps
of Engineers 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. NMFS published a notice of a
proposed IHA and request for comments in the Federal Register on
October 10, 2023 (88 FR 74451). On March 5, 2024, NMFS issued an IHA
that was effective from April 1, 2024 through March 31, 2025 (89 FR
17423, March 11, 2024). In-water work associated with the project was
expected to be completed between April and October 2024.
On September 23, 2024, USAF informed NMFS that work on the project
had experienced significant delays due to piling production delays and
weather and would not be completed during the 2024 IHA time period USAF
completed a portion of the construction work that was covered by the
2024 IHA and submitted a monitoring report demonstrating that the
required mitigation and monitoring requirements were satisfied, no
impacts of a scale or nature not previously analyzed or authorized
occurred as a result of the activities conducted, and the IHA holder
did not exceed the authorized levels of take under that IHA.
On September 23, 2024, NMFS received a letter from USAF requesting
renewal of the 2024 IHA (2024 request) to conduct nearly identical
construction activities that were previously analyzed under the 2024
IHA. On May 3, 2024, NMFS published (89 FR 36762) and solicited public
comment on its draft updated Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing Underwater and
In-Air Criteria for Onset of Auditory Injury and Temporary Threshold
Shifts (Version 3.0) (2024 Technical Guidance), which includes updated
thresholds and weighting functions to inform auditory injury (AUD INJ)
estimates. The public comment period ended on June 17th, 2024, and the
2024 Technical Guidance was finalized on October 24, 2024. While USAF's
planned activity would ordinarily qualify for a renewal of the IHA,
NMFS determined that a renewal of the 2024 IHA is not appropriate in
this case because application of the updated Guidance indicates that
substantial modification of the prescribed shutdown zones and updates
to authorized take numbers for certain species is appropriate.
On December 16, 2024, USAF revised their request to indicate that
all work completed during the 2024 season would need to be redone, due
to shifting sediments and improperly functioning piles. As such, the
same work analyzed under the 2024 IHA is planned for the current IHA,
across the same number of construction days. This includes the (1)
installation of 208 42-inch (107 cm) round steel interlocking pipe
piles (2) the installation of 60 30-inch (76 cm) steel template piles
and, (3) the removal of 64 30-inch steel template piles, which includes
the removal of 4 additional piles that were installed under the 2024
IHA.
Additionally, USAF also requested to reduce the size of the
shutdown zones established for low-frequency cetaceans due to
practicability concerns associated with excessive fog. Under this IHA,
USAF plans to conduct pile driving activities between the in water work
window dates of April 2025 through
[[Page 17411]]
October 2025. The activities are nearly identical to those analyzed
under the 2024 IHA, but the mitigation zones and number of authorized
takes have been adjusted to account for the isopleths calculated using
the 2024 Technical Guidance and the request to adjust the shutdown zone
for low frequency cetaceans. The USAF request was deemed adequate and
complete on January 23, 2024. In evaluating the request, and where
applicable, NMFS relies on the information previously presented in
notices associated with issuance of the 2024 IHA (88 FR 74451, October
31, 2023; 89 FR 17423, March 11, 2024).
Description of the Specified Activity and Anticipated Impacts
USAF is conducting 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 and Level B harassment, include
down-the-hole drilling, vibratory and impact installation of temporary
and permanent steel interlocking pipe piles, and vibratory removal of
temporary steel interlocking pipe piles. The marine construction
associated with the activities is planned to occur over 160 days,
between April and October 2025. The IHA is effective from Date to Date.
The fuel pier replacement project includes the installation of an
interlocking steel pipe combi-wall system, which requires (1)
installation of 208 42'' round steel interlocking pipe piles (2)
installation of 60 30-inch steel template pipe piles and (3) removal of
64 30'' template pipe piles, which includes the removal of 4 additional
piles that were installed under the 2024 IHA, across the same number of
construction days (n=160) between April and October 2025.
A detailed description of the construction project is provided in
the Federal Register notice for the proposed 2024 IHA (88 FR 74451,
October 31, 2023) and the proposed 2025 IHA (90 FR 11952, March 13,
2025). Therefore, a detailed description is not provided here. Please
refer to the Federal Register notices 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 DATE (90 FR 11952, March 13, 2025). 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 persons submit relevant information, suggestions, and
comments. During the 30-day public comment period, NMFS did not receive
any substantive comments on the proposed IHA.
Description of Marine Mammals
A detailed description of the species likely to be affected by
USAF's Fuel Pier Repair project, including brief introductions to the
species and relevant stocks, 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. A summary of species is provided in
table 1. NMFS reviewed the most recent SARs, including the draft 2024
SARs, (found on NMFS' website at <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>), up-
to-date information on relevant Unusual Mortality Events (UMEs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-unusual-mortality-events">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-unusual-mortality-events</a>), and recent scientific literature and
determined that the new information does not change our original
analysis of impacts under the 2024 IHA. Please refer to that Federal
Register notice for these descriptions. Please also refer to NMFS'
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) for generalized
species accounts.
Table 1--Species Likely Impacted by the Specified Activities
----------------------------------------------------------------------------------------------------------------
Stock abundance
ESA/MMPA (CV, Nmin, most
Common name Scientific name Stock status; recent PBR Annual M/
strategic abundance SI \3\
(Y/N) \1\ survey) \2\
----------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
----------------------------------------------------------------------------------------------------------------
Family Balaenopteridae:
Fin whale................ Balaenoptera Northeast E, D, Y UND (UND, UND, UND 0.6
physalus. Pacific. 2013) \4\.
Humpback whale........... Megaptera Western North E, D, Y 1,084, (0.088, 3.4 5.82
novaeangliae. Pacific. 1,007, 2006).
Mexico--North T, D, Y N/A (N/A, N/A, UND 0.56
Pacific. 2006) \5\.
Hawai[revaps]i. -, -, N 11,278 (0.56, 127 19.6
7,265, 2020).
Minke whale.............. Balaenoptera Alaska......... -, -, - N/A (N/A, N/A, UND 0
acutorostrata. N/A) \6\.
----------------------------------------------------------------------------------------------------------------
Odontoceti (toothed whales, dolphins, and porpoises)
----------------------------------------------------------------------------------------------------------------
Family Physeteridae:
Sperm whale.............. Physeter North Pacific.. E, D, Y UND (UND, UND, UND 3.5
macrocephalus. 2015) \7\.
Family Ziphiidae (beaked
whales):
Baird's beaked whale..... Berardius Alaska......... -, -, N N/A (N/A, N/A, N/A 0
bairdii. N/A) \8\.
Stejneger's beaked whale. Mesoplodon Alaska......... -, -, N N/A (N/A, N/A, N/A 0
stejnegeri. N/A) \8\.
Family Delphinidae:
Killer whale............. Orcinus orca... ENP Alaska -, -, N 1,920 (N/A, 19 1.3
Resident Stock. 1,920, 2019).
ENP Gulf of -, -, N 587 (N/A, 587, 5.9 0.8
Alaska, 2012).
Aleutian
Islands, and
Bering Sea.
Family Phocoenidae
(porpoises):
Dall's porpoise.......... Phocoenoides Alaska......... -, -, N UND (UND, UND, UND 37
dalli. 2015) \9\.
Harbor porpoise.......... Phocoena Bering Sea..... -, -, N UNK (UNK, N/A, UND 1.8
phocoena. 2008) \10\.
----------------------------------------------------------------------------------------------------------------
[[Page 17412]]
Order Carnivora--Pinnipedia
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Family Otariidae (eared seals
and sea lions):
Northern fur seal........ Callorhinus Eastern Pacific -, D, Y 612,765 (0.2, 11,151 296
ursinus. 518,651, 2022).
Steller sea lion......... Eumetopias Western, U.S... E, D, Y 49,837 (N/A, 299 267
jubatus. 49,837, 2022)
\11\.
Family Phocidae (earless
seals):
Harbor seal.............. Phoca vitulina. Aleutian -, -, N 5,588 (N/A, 97 90
Islands. 5,366, 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: <a href="https://www.nmfs.noaa.gov/pr/sars">https://www.nmfs.noaa.gov/pr/sars</a>. CV is coefficient
of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable.
\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.
\11\ Nest is best estimate of counts, which have not been corrected for animals at sea during abundance surveys.
Estimates provided are for the U.S. only. The overall Nmin is 73,211 and overall PBR is 439.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al.
(2007, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). Subsequently, NMFS (2018, 2024)
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.
Note that since the issuance of the 2024 IHA, NMFS' 2024 Technical
Guidance was finalized and has been incorporated into this analysis.
The re-named marine mammal hearing groups that have been incorporated
into this 2025 IHA are presented in table 2. The references, analysis,
and methodology used in the development of the thresholds are described
in the 2024 Technical Guidance, which may be accessed at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 2--Marine Mammal Hearing Groups
[NMFS 2024]
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Hearing group Generalized hearing range *
----------------------------------------------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 36 kHz.
whales).
High-frequency (HF) cetaceans (dolphins, 150 Hz to 160 kHz.
toothed whales, beaked whales,
bottlenose whales).
Very High-frequency (VHF) cetaceans 200 Hz to 165 kHz.
(true porpoises, Kogia, river dolphins,
Cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true 40 Hz to 90 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 68 kHz.
lions and fur seals).
----------------------------------------------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a composite (i.e., all species within the
group), where individual species' hearing ranges may not be as broad. Generalized hearing range chosen based
on ~65 dB threshold from composite audiogram, previous analysis in NMFS 2018, and/or data from Southall et al.
2007; Southall et al. 2019. Additionally, animals are able to detect very loud sounds above and below that
``generalized'' hearing range. Hz = Hertz. kHz = kilohertz.
[[Page 17413]]
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2024) for a review of available information.
Potential Effects on Marine Mammals and Their Habitat
The effects of underwater noise from USAF's construction activities
have the potential to result in the harassment of marine mammals in the
vicinity of the project area. The notice of proposed 2024 IHA (88 FR
74451, October 31, 2024) included a discussion of the effects of
anthropogenic noise on marine mammals and the potential effects of
underwater noise from USAF's construction on marine mammals and their
habitat. That information and analysis is not repeated here; please
refer to the notice of proposed 2024 IHA (88 FR 74451, October 31,
2024).
Estimated Take
A detailed description of the methods and inputs used to estimate
authorized take is found in these previous documents. The methods of
estimating take by Level B harassment for the 2025 IHA are identical to
those used in the 2024 IHA. The source levels and days of operation
remain unchanged from the previously issued IHA. Data reported in the
marine mammal monitoring report suggest a greater occurrence of harbor
seal than estimated for the 2024 IHA. To account for the revised
isopleths, mitigation zones, and marine mammal occurrence information,
take by Level A and Level B harassment has been revised for six
species.
Level A harassment--NMFS' 2024 Technical Guidance (NMFS, 2024)
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). Between the issuance of the 2024 IHA and
this 2025 IHA, NMFS' 2024 Technical Guidance was updated and has been
incorporated into this analysis. USAF's activity includes the use of
impulsive (impact pile driving and down-the-hole drilling (DTH)) and
non-impulsive (continuous pile driving and DTH) sources.
The updated thresholds, which identify the onset of AUD INJ based
on the 2024 Technical Guidance, have been incorporated in this IHA are
presented in table 3. The references, analysis, and methodology used in
the development of the thresholds are described in the 2024 Technical
Guidance, which may be accessed at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>. NMFS defines AUD INJ as ``damage to the inner ear that can
result in destruction of tissue. . .which may or may not result in
PTS'' (NMFS 2024). NMFS defined PTS as a permanent, irreversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a previously established
reference level (NMFS, 2024).
Table 3--Thresholds Identifying the Onset of Auditory Injury Based on 2024 Technical Guidance
----------------------------------------------------------------------------------------------------------------
AUD INJ onset thresholds * (received level)
Hearing group -------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans.......... Cell 1: L0-pk,flat: 222 Cell 2: LE,LF,24h: 197 dB.
dB; LE,LF,24h: 183 dB.
High-Frequency (HF) Cetaceans......... Cell 3: L0-pk,flat: 230 Cell 4: LE,HF,24h: 201 dB.
dB; LE,HF,24h: 193 dB.
Very High-Frequency (VHF) Cetaceans... Cell 5: L0-pk,flat: 202 Cell 6: LE,VHF,24h: 181 dB.
dB; LE,VHF,24h: 159 dB.
Phocid Pinnipeds (PW) (Underwater).... Cell 7: L0-pk,flat: 223 Cell 8: LE,PW,24h: 195 dB.
dB; LE,PW,24h: 183 dB.
Otariid Pinnipeds (OW) (Underwater)... Cell 9: L0-pk,flat: 230 Cell 10: LE,OW,24h: 199 dB.
dB; LE,OW,24h: 185 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating AUD
INJ onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
associated with impulsive sounds, these thresholds are recommended for consideration.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 micropascal ([mu]Pa), and weighted
cumulative sound exposure level (LE,) has a reference value of 1[mu]Pa\2\s. In this table, thresholds are
abbreviated to be more reflective of International Organization for Standardization standards (ISO 2017). The
subscript ``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within
the generalized hearing range of marine mammals [i.e., 7 Hz to 165 kHz]. The subscript associated with
cumulative sound exposure level thresholds indicates the designated marine mammal auditory weighting function
(LF, HF, and VHF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours.
The weighted cumulative sound exposure level 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 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).
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 each year are presented in table 4. Source
levels for vibratory installation and removal of piles of the same
diameter are assumed to be the same.
Table 4--Estimates of Mean Underwater Sound Levels * Generated During Vibratory, Impact, and DTH Pile
Installation and Vibratory Pile Removal at 10 m
----------------------------------------------------------------------------------------------------------------
Pile driving method Pile type Pile size dB RMS dBPeak dBSEL Reference
----------------------------------------------------------------------------------------------------------------
Vibratory Installation and Temporary steel 30 166 N/A N/A NMFS 2023
Removal. pipe pile. Analysis.
Round 42 168.2 N/A N/A Port of Anchorage
interlocking Test Pile
steel pipe pile. Program (table
16 in Austen et
al., 2016).
Impact Installation........... Temporary steel 30 191 212 171 Caltrans, 2020.
pipe pile.
Round 42 192 213 179 Caltrans, 2020.
interlocking
steel pipe pile.
[[Page 17414]]
Down-the-Hole Installation.... Temporary steel 30 174 ** 194 ** 164 Reyff & Heyvaert
pipe pile. 2019, Reyff,
2020, Denes et
al., 2019.
Round 42 174 ** 194 ** 164 Reyff & Heyvaert
interlocking 2019, Reyff,
steel pipe pile. 2020, Denes et
al., 2019.
----------------------------------------------------------------------------------------------------------------
Note: dB peak = peak sound level; rms = root mean square; SEL = sound exposure level.
* All sound levels are referenced at 10 m.
** A typographical error has been corrected in which the sound levels listed for DTH activities (dB Peak and dB
SEL) were incorrectly listed in the other's respective column.
TL is the decrease in acoustic intensity as an acoustic pressure
wave propagates out from a source. TL parameters vary with frequency,
temperature, sea conditions, current, source and receiver depth, water
depth, water chemistry, and bottom composition and topography. The
general formula for underwater TL is:
TL = B x Log10 (R<INF>1</INF>/R<INF>2</INF>),
where:
TL = transmission loss in dB
B = transmission loss coefficient
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile, and
R<INF>2</INF> = the distance from the driven pile of the initial
measurement
Absent site-specific acoustical monitoring with differing measured
TL, a practical spreading value of 15 is used as the TL coefficient in
the above formula. Site-specific TL data for Alcan Harbor 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 2024 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 AUD INJ, which includes, but is not limited to, PTS. Inputs used
in the optional User Spreadsheet tool are identical to those analyzed
under the 2024 IHA. Table 5 provides the calculated Level A harassment
isopleths that are based the 2024 Technical Guidance that are
incorporated into this analysis compared with the calculated Level A
harassment isopleths that were based on the 2018 Technical Guidance and
presented in the proposed FRN for the 2024 IHA (88 FR 74451, October
31, 2023).
There were no substantive changes to Level A harassment isopleths
for low frequency cetaceans (they increased slightly during vibratory
activities and decreased slightly during impact pile driving). However,
for high-frequency cetaceans (categorized as mid-frequency cetaceans
prior to application of the 2024 Technical Guidance), phocids, and
otariids, Level A harassment isopleths increased substantially during
all pile driving activities. Additionally, for very high frequency
cetaceans (categorized as high frequency cetaceans prior to application
of the 2024 Technical Guidance), Level A harassment isopleths decreased
slightly during vibratory activities and substantially during impact
pile driving.
Table 5--Level A Harassment and Level B Harassment Isopleths and Associated Areas From Vibratory and Impact Pile Driving, Vibratory Removal, and DTH
Drilling Using the 2024 Technical Guidance
[Level A harassment isopleths based on 2018 guidance, used in the 2024 IHA analysis, are presented in parentheses]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment isopleths (m) Level B
-------------------------------------------------------------------------------------------- harassment
Pile size/type isopleth
LF HF \1\ VHF \2\ PW OW (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory
--------------------------------------------------------------------------------------------------------------------------------------------------------
42-inch Interlocking Steel..................... 44.2 (32.7) 17.0 (2.9) 36.1 (48.4) 56.9 (19.9) 19.2 (1.4) 16,343
30-inch Steel Pipe............................. 19.9 (14.7) 7.6 (1.3) 16.2 (21.8) 25.6 (8.9) 8.6 (0.6) 11,659
--------------------------------------------------------------------------------------------------------------------------------------------------------
DTH
--------------------------------------------------------------------------------------------------------------------------------------------------------
42-inch Interlocking Steel..................... 2,540 (2,549.4) 324.1 (90.7) 3,930.8 (3,036.7) 2,256.5 (1,364.3) 841.1 (99.3) 39,811
30-inch Steel Pipe............................. 2,249.4 (2,257.6) 287.0 (80.3) 3,480.9 (2,689.2) 1,998.2 (1,208.2) 744.9 (88) 39,811
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact
--------------------------------------------------------------------------------------------------------------------------------------------------------
42-inch Interlocking Steel..................... 2007.8 (2.015.1) 256.2 (71.7) 3,107.0 (2,400.3) 1,783.6 (1,078.4) 664.9 (78.5) 1,359
30-inch Steel Pipe............................. 930.4 (933.8) 118.7 (33.2) 1,439.9 (1,112.3) 826.6 (499.7) 308.1 (36.4) 1,166
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Species that were considered Mid-Frequency cetaceans under the NMFS 2018 Technical Guidance are now considered High Frequency cetaceans.
\2\ Species that were considered High-Frequency cetaceans under the NMFS 2018 Technical Guidance are now considered Very High Frequency cetaceans.
[[Page 17415]]
Except for harbor seal, the same occurrence assumptions that were
used to estimate take for the 2024 IHA and described in the associated
proposed FRN (88 FR 74451, October 31, 2024) are applied here, as is
the same duration information. In cases where site specific marine
mammal monitoring data are available, marine mammal occurrence
assumptions and pile driving durations are based on hourly estimates.
In cases where no marine mammal observations were reported, marine
mammal occurrence assumptions and pile driving durations are based on
daily estimates.
During monitoring completed in 2024, 29 harbor seal and 6 Steller
sea lion were observed in the project area (at a rate of 0.45 and 0.09
groups of one of each species per hour, respectively). A total of six
harbor seal and two Steller sea lion were reported within the Level B
harassment zone while construction activities were underway. This
suggests a revision to harbor seal occurrence estimates is appropriate;
0.45 harbor seals per hour were reported during 2024 activities rather
than the previously estimated 0.14 harbor seal per hour used in the
analysis for the 2024 IHA.
The equation used to estimate take by Level B harassment for all
species is:
Exposure Estimate = marine mammal occurrence x duration of pile driving
During all vibratory pile driving activities for all hearing
groups, and during all other activities for high frequency cetaceans
(categorized as mid-frequency cetaceans in the 2024 IHA and prior to
the application of the 2024 Technical Guidance) USAF will implement
shutdown zones equivalent to the estimated Level A harassment
isopleths. For all other hearing groups, during DTH and impact pile
driving, shutdown zones are established at the distance that these
species are assumed to be able to be reliably observed under typical
conditions at the location (1000 meters (m) for LF, 500 m for VHF,
previously categorized as HF in the 2024 IHA and prior to the
application of the 2024 Technical Guidance; and 400 m for pinnipeds).
To calculate estimated take by Level A harassment in cases where
the Level A harassment isopleth is larger than the Level B harassment
isopleth, the same equation to estimate take by Level B harassment is
applied. Exposure estimates for those activities are attributed to take
by Level A harassment.
To calculate estimated take by Level A harassment in cases where
the Level A harassment isopleth is larger than the planned shutdown
zone, but smaller than the Level B harassment isopleth, we
proportionally compared, by hearing group, the portion of the largest
Level A harassment area (square kilometers (km\2\)) that exceeds the
planned shutdown zone area (km\2\) to the area (km\2\) (referred to as
the Level A harassment impact area) of the largest Level B harassment
isopleth across that pile type (typically from vibratory pile driving).
This ratio was then multiplied by the total estimated marine mammal
exposures:
Take by Level A harassment = Level A harassment impact area (km\2\)/
Level B harassment area (km\2\) x total marine mammal exposures.
Monitoring data collected during work at the project site indicate
that all Steller sea lion were observed within 200 m of the project
site, and harbor seal were observed between 50 m and 500 m in 2021 and
85 and 600 m in 2024. As such, for harbor seal and Steller sea lion,
NMFS determined that the methods above could underestimate potential
take by Level A harassment. NMFS accordingly estimated additional takes
by Level A harassment by determining the ratio of each species that
were observed beyond the shutdown zone compared to the number of
individuals that were observed closer to construction activities during
the EAS fuel pier emergency repair completed in 2021 and 2024, and
multiplying this ratio by the total exposures.
Note that in the 2024 IHA, an additional approach to estimate take
by Level A harassment was employed to account for cases in which a
shutdown zone was established at the Level A harassment isopleth, but a
portion of the shutdown zone was not expected to be reliably
observable. Since the shutdown zones for low frequency cetaceans have
been reduced to address practicability concerns, this scenario is no
longer applicable and as such, that approach is not summarized here or
applied to take estimates for any hearing group.
Fin Whale
One group of eight fin whale is predicted every 2 construction
months (60 days). The duration of the construction is 160 days (2.65 is
the basic 60 day period that corresponds to 2 construction months).
This results in 21 takes by Level B harassment of fin whale (8 fin
whale x 2.65 2-month periods).
During DTH activities, the Level A harassment isopleth is larger
than the shutdown zone, but smaller than the Level B harassment
isopleth. Estimated take by Level A harassment for these activities
results in 0.084 based on (5.8 km\2\/1,285.9 km\2\) x 21 fin whale
exposures = 0.084 takes by Level A harassment. During impact pile
driving of 42-inch piles, the Level A harassment isopleth is larger
than the Level B harassment isopleth. Estimated take by Level A
harassment for these activities results in 6.88 based on 8 fin whale x
0.86 months of 42-inch impact pile driving.
Takes by Level B harassment were modified to deduct the amount of
take by Level A harassment (i.e., 21 - 6.88 - 0.084 = 14). Therefore,
NMFS authorizes 7 takes by Level A harassment and 14 takes by Level B
harassment for fin whale, for a total of 21 takes.
Humpback Whale
A total of 0.07 groups of two humpback whale are predicted every
construction hour. The duration of the construction hours is 1,101.
This results in 154 takes by Level B harassment of humpback whale (0.07
groups x 2 humpback whale x 1,101 hours).
During DTH activities, the Level A harassment isopleth is larger
than the shutdown zone, but smaller than the Level B harassment
isopleth. Estimated take by Level A harassment for these activities
results in 0.616 based on (5.8 km\2\/1,285.9 km\2\) x 154 exposures =
0.616 takes by Level A harassment. During impact pile driving of 42-
inch piles, the Level A harassment isopleth is larger than the Level B
harassment isopleth. Estimated take by Level A harassment for these
activities results in 21.84 based on 0.07 humpback whales x 2 groups x
156 hours.
Takes by Level B harassment were modified to deduct the amount of
take by Level A harassment (i.e., 154-21.84-0.616 = 131). Therefore,
NMFS authorizes 23 takes by Level A harassment for humpback whale and
131 takes by Level B harassment for humpback whale, for a total of 22
takes.
Minke Whale
One group of three minke whale is predicted every 2 construction
months (60 days). The duration of the construction is 160 days (2.65 is
the basic 60 day period that corresponds to 2 construction months).
This results in eight takes by Level B harassment of minke whale (3
minke whale x 2.65 2-month periods).
During DTH activities, the Level A harassment isopleth is larger
than the shutdown zone, but smaller than the Level B harassment
isopleth. Estimated take by Level A harassment for these
[[Page 17416]]
activities results in 0.032 based on (5.8 km\2\/1,285.9 km\2\) x 8
minke whale exposures = 0.032 takes by Level A harassment. During
impact pile driving of 42-inch piles, the Level A harassment zone is
larger than the Level B harassment zone. Estimated take by Level A
harassment for these activities results in 2.58 minke whale based on 3
minke whale x 0.86 months of 42-inch impact pile driving. Takes by
Level B harassment were modified to deduct the amount of take by Level
A harassment (i.e., 8-2.58-0.032 = 5). Therefore, NMFS authorizes three
takes by Level A harassment and five takes by Level B harassment for
minke whale, for a total of eight takes.
Sperm Whale
Two groups of four sperm whale is predicted every 1 construction
month. The duration of the construction is 5 months. This results in 40
takes by Level B harassment of sperm whale (2 groups x 4 sperm whale x
5 construction months).
Takes by Level A harassment for sperm whales are not anticipated
nor are they authorized.
Baird's Beaked Whale
One 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 authorizes 10 takes of Baird's beaked
whale by Level B harassment.
Takes by Level A harassment for Baird's beaked whale were not
anticipated nor are they authorized.
Stejneger's Beaked Whale
One group of eight Stejneger'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 authorizes eight takes of
Stejneger's beaked whale by Level B harassment.
Takes by Level A harassment for Stejneger's beaked whale were not
anticipated nor are they authorized.
Killer Whale
A total of 0.02 groups of 8 killer whale is predicted every
construction hour. The duration of the construction hours is 1,101.
This results in 176 takes by Level B harassment of killer whale (0.02
groups x 8 killer whale x 1,101 hours).
Takes by Level A harassment for killer whale were not anticipated
nor are they authorized.
Dall's Porpoise
One group of 15 Dall's porpoise is predicted every 2 construction
months (60 days). The duration of the construction is 160 days (2.65 x
the basic 60 day period that corresponds to 2 construction months).
This results in 15 takes by Level B harassment of Dall's porpoise (15
Dall's porpoise x 2.65 2-month periods = 39 takes by Level B
harassment).
During DTH activities, the Level A harassment isopleth is larger
than the shutdown zone, but smaller than the Level B harassment
isopleth. Estimated take by Level A harassment for these activities
results in 0.48 takes based on (15.62 km\2\/1,285.9 km\2\) x 40
exposures = 0.48. During all impact pile driving, the Level A
harassment isopleth is larger than the Level B harassment isopleth.
Estimated take by Level A harassment for these activities result in
18.4 based on 1 group x 15 Dall's porpoise x 0.86 months of 42-inch
impact pile driving and 1 group x 15 Dall's porpoise x 0.37 months of
30-inch impact pile driving (12.9 + 5.5 = 18.4 takes by Level A
harassment).
Takes by Level B harassment were modified to deduct the authorized
amount of take by Level A harassment (i.e., 39-18.4-0.48 = 20).
Therefore, NMFS authorizes 19 takes by Level A harassment and 20 takes
by Level B harassment for Dall's porpoise, for a total of 39 takes.
Harbor Porpoise
One group of three harbor porpoise is predicted every 1
construction month. The duration of the construction is 5 months. This
results in 15 takes by Level B harassment of harbor porpoise (1 group x
3 harbor porpoise x 5 months).
During DTH activities, the Level A harassment isopleth is larger
than the shutdown zone, but smaller than the Level B harassment
isopleth. Estimated take by Level A harassment during these activities
results in 0.18 based on (15.6 km\2\/1,285.9 km\2\) x 15 harbor
porpoise exposures. During all impact pile driving activities, the
Level A harassment isopleth is larger than the Level B harassment
isopleth. This results in 8.8 takes by Level A harassment based on 1
group x 3 harbor porpoise x 0.17 months of 42-inch impact pile driving
and 1 group x 3 harbor porpoise x 0.73 months of 30-inch impact pile
driving (i.e., 5.1 + 3.73 = 8.83).
Takes by Level B harassment were modified to deduct the authorized
amount of take by Level A harassment (i.e., 15-8.83-0.18 = 6).
Therefore, NMFS authorizes 6 takes by Level A harassment and 9 takes by
Level B harassment for harbor porpoise, for a total of 15 takes.
Northern Fur Seal
To account for the unlikely but small possibility that northern fur
seals could occur in the project area NMFS estimates that one group of
one northern fur seal could occur in the project area each construction
month either in the Level B or Level A harassment isopleth. As such,
NMFS authorizes a maximum total of five takes of northern fur seal by
either Level B or Level A harassment.
Steller Sea Lion
A total of 0.09 groups of one Steller sea lion is predicted every
construction hour. The duration of the construction is 1,101 hours.
This results in 99 takes by Level B harassment of Steller sea lion
(0.09 Steller sea lion x 1 group x 1,101 hours = 99 takes by Level B
harassment).
During DTH activities, the Level A harassment isopleth is larger
than the shutdown zone, but smaller than the Level B harassment
isopleth. Estimated take by Level A harassment for these activities
results in 0.0007 based on (0.91 km\2\/1,285.9 km\2\) x 154 exposures.
Monitoring data collected during work completed at the project site
in 2021 and 2024 indicate that Steller sea lion occasionally occur
within the project area, within 200 m from shore; on 6 days in 2021, 7
Steller sea lion were observed between 25 m and 175 m from the project
site. On 3 days in 2024, 6 Steller sea lion were observed between 100
and 200 m of the project site. Because Steller sea lion typically
inhabit areas closer to shore rather than distances represented by the
largest level B harassment isopleth (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 Steller sea lion that were
observed beyond the shutdown zone isopleth compared to the Steller sea
lion that were observed closer to construction activities during the
EAS fuel pier emergency repair that was completed in 2021 and EAS fuel
pier repair activities completed in 2024. However, all Steller sea lion
reported by PSOs during that project were reported within the
established shutdown zone (n = 13). To be conservative, NMFS assumes
that a small proportion (10 percent) of Steller sea lion predicted to
occur within the project area during construction could occur outside
of the shutdown zone. As such, NMFS
[[Page 17417]]
predicts that 10 Steller sea lion (99 total exposures x 0.1 = 9.9 takes
by Level A harassment).
Takes by Level B harassment were modified to deduct the authorized
amount of take by Level A harassment (i.e., 99-10 = 89 takes by Level B
harassment). Therefore, NMFS authorizes 10 takes by Level A harassment
and 89 takes by Level B harassment for Steller sea lion, for a total of
154 takes.
Harbor Seal
A total of 0.45 groups of one harbor seal is predicted every
construction hour. This is increased from the predicted 0.14 groups of
one harbor seal every construction hour used in the 2024 IHA due to
application of the most recent monitoring data. The duration of the
construction hours is 1,101. This results in 495 takes by Level B
harassment of harbor seal based on 0.45 harbor seal x 1 group x 1,101
hours.
During DTH activities, the Level A harassment isopleth is larger
than the shutdown zone, but smaller than the Level B harassment
isopleth. Estimated take by Level A harassment for these activities
results in 2.0 based on (4.8 km\2\/1,285.9 km\2\) x 495 exposures.
Because harbor seals typically inhabit areas closer to shore rather
than distances represented by the largest Level B harassment 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 and EAS fuel pier repair activities completed in 2024 (i.e.,
14/67 = 0.21 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., 0.21 x 495 exposures = 104) for a total of 146 takes
by Level A harassment (2.0 + 104 = 106).
Additionally, during impact pile driving of 42-inch piles, the
Level A harassment isopleth is larger than the Level B harassment
isopleth. Estimated take by Level A harassment during these activities
results in 70.2 based on 0.45 harbor seal x 1 group x 156 hours.
Takes by Level B harassment were modified to deduct the authorized
amount of take by Level A harassment (i.e., 495-106-70 = 319 takes by
Level B harassment).
Therefore, NMFS authorizes 176 takes by Level A harassment and 319
takes by Level B harassment for harbor seal, for a total of 495 takes.
See table 6 for all authorized take numbers, by species, and the
respective amount of the population that take represents.
Table 6--Authorized Take by Stock and Harassment Type and as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
Authorized take Authorized take
-------------------------- as a percentage
Species Stock Level B Level A of stock
harassment harassment abundance
----------------------------------------------------------------------------------------------------------------
Fin whale.............................. Northeast Pacific......... 14 7 <1
Humpback whale......................... Western North Pacific..... 3 1 <1
Mexico--North Pacific..... 10 2 1.3
Hawai[revaps]i............ 118 20 <1
Minke whale............................ Alaska.................... 5 3 <1
Sperm whale............................ North Pacific............. 40 0 16.2
Baird's beaked whale................... Alaska.................... 10 0 (*)
Stejneger's beaked whale............... Alaska.................... 8 0 (*)
Killer whale........................... ENP Alaska Resident....... 176 0 9.1
ENP Gulf of Alaska, ........... ........... 30
Aleutian Islands, and
Bering Sea.
Dall's porpoise........................ Alaska.................... 21 19 <1
Harbor porpoise........................ Bering Sea................ 9 6 <1
Northern fur seal Eastern Pacific........... 5 ........... <1
Steller sea lion....................... Western, U.S.............. 89 10 <1
Harbor seal............................ Aleutian Islands.......... 319 176 9.0
----------------------------------------------------------------------------------------------------------------
* Reliable abundance estimates for these stocks are currently unavailable.
Description of Mitigation, Monitoring and Reporting Measures
The mitigation, monitoring, and reporting measures are nearly
identical to those included in the Federal Register notice announcing
the final 2024 IHA (89 FR 17423, May 15, 2024), and the discussion of
the least practicable adverse impact included in that document remains
accurate. The only change is to the size of the shutdown zones, which
have been revised in accordance with the updated Level A harassment
isopleths calculated using the 2024 Technical Guidance. Additionally,
shutdown zones for low-frequency cetaceans are decreased to 1000 m from
2,100-2,600 m during impact and DTH activities to address issues with
observability. During 2024 activities, USAF reported that PSO's were
unable to reliably observe for LF cetaceans at the Level A harassment
isopleth due to excessively foggy conditions. The measures included in
this authorization are found below.
Establishment of Shutdown Zone--For all pile driving/removal and
DTH activities, USAF will 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 7). In most cases, the shutdown zones are based on
the estimated Level A harassment isopleth distances for each hearing
group. However, in cases where it would be challenging to detect marine
mammals at the Level A harassment isopleth, smaller shutdown zones have
been established (table 7). Additionally, per the 2024 IHA, the USAF
will implement a minimum shutdown zone of 25 m during all pile driving
and removal activities and DTH.
Construction supervisors and crews, PSOs, and relevant USAF staff
must avoid direct physical interaction with
[[Page 17418]]
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 7, 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 7--Shutdown Zones
----------------------------------------------------------------------------------------------------------------
Shutdown zones
Activity Pile diameter ----------------------------------------------------------------
LF HF VHF PW OW
----------------------------------------------------------------------------------------------------------------
Vibratory Installation and 42-in........... 50 50 50 60 50
Removal.
30-in........... 25 25 25 30 25
DTH.......................... 42-in........... 1,000 350 500 400 400
30-in........... ........... 290
Impact....................... 42-in........... ........... 260
30-in........... ........... 120
----------------------------------------------------------------------------------------------------------------
Protected Species Observers (PSOs)--The number and placement of
PSOs during all construction activities (described in the Visual Marine
Mammal Observation section) will ensure that the entire shutdown zone
is visible. USAF will employ at least two PSOs for all pile driving and
DTH activities.
Monitoring for Level B Harassment--PSOs will 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
are 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 procedure will be conducted a total of three times before
impact pile driving begins. Soft start will be implemented at the start
of each day's impact pile driving and at any time following cessation
of impact pile driving for a period of 30 minutes or longer. Soft start
is not required during vibratory pile driving and removal activities.
Visual Marine Mammal Observation--Monitoring must be conducted by
qualified marine mammal observers (MMOs), who are trained biologists,
with minimum qualifications described in the Federal Register notice of
the issuance of the 2024 IHA (89 FR 17423, March 11, 2024). In order to
effectively monitor the pile driving monitoring zones, two trained PSOs
must be positioned at the best practical vantage point(s) as described
in the Federal Register notice of the issuance of the 2024 IHA. PSOs
shall record specific information on the sighting forms as described in
the Federal Register notice of the issuance of the 2024 IHA. At the
conclusion of the in-water construction work, USAF will provide NMFS
with a monitoring report that includes information described in the
2024 IHA Federal Register Notice.
Determinations
USAF plans to conduct activities nearly identical to those covered
in the previous 2024 IHA. We have revised the Level A harassment and
mitigation zones to incorporate and address the 2024 Technical
Guidance, which results in different Level A harassment isopleths.
When issuing the 2024 IHA, NMFS found the EAS Fuel Pier repair
project, in its entirety, would have a negligible impact to species or
stocks' rates of recruitment and survival and the amount of taking
would be small relative to the population size of such species or stock
(less than 3 percent for all stocks except sperm whale, killer whale,
and harbor seal, which are less than 30 percent). As described above,
the total number of authorized takes for each stock are the same as the
takes authorized in the 2024. In cases where take by Level A harassment
has increased, it has only increased a small amount (take by Level A
harassment has increased by 4 for fin whale, by 6 for Dall's porpoise,
by 1 for harbor porpoise, and by 21 by harbor seal. While no take by
Level A harassment was authorized under the 2024 IHA for
[[Page 17419]]
Steller sea lion and northern fur seal, only a small amount is
authorized through this IHA. The anticipated impacts from the project
are similar to those previously analyzed. The IHA includes the same
monitoring, and reporting measures as the 2024 IHA and the shutdown
zones have been revised to address the new Level A harassment isopleths
calculated from the 2024 technical guidance. In conclusion, there is no
new information suggesting that our analysis or findings should change.
Based on the information contained here and in the referenced
documents, NMFS has determined the following: (1) the required
mitigation measures will affect the least practicable impact on marine
mammal species or stocks and their habitat; (2) the authorized takes
will have a negligible impact on the affected marine mammal species or
stocks; (3) the authorized takes represent small numbers of marine
mammals relative to the affected stock abundances; (4) USAF's
activities will not have an unmitigable adverse impact on taking for
subsistence purposes as no relevant subsistence uses of marine mammals
are implicated by this action, and (5) appropriate monitoring and
reporting requirements are included.
Endangered Species Act (ESA)
There are four marine mammal species (western Distinct Population
Segment (DPS) Steller sea lion, fin whale (northeast Pacific), humpback
whale (Mexico--North Pacific and western North Pacific), and sperm
whale (North Pacific)) with confirmed occurrence in the project area
that are listed as endangered under the ESA. The NMFS Alaska Regional
Office issued a Biological Opinion under Section 7 of the ESA on the
issuance of an IHA to USAF under section 101(a)(5)(D) of the MMPA by
NMFS Office of Protected Resources. The Biological Opinion concluded
that the action is not likely to jeopardize the continued existence of
the listed species and is not likely to destroy or adversely modify
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 review our proposed action (i.e., the issuance of an IHA)
with respect to potential impacts on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NAO 216-6A, which do not
individually or cumulatively have the potential for significant impacts
on the quality of the human environment and for which we have not
identified any extraordinary circumstances that would preclude this
categorical exclusion. Accordingly, NMFS has determined that the
issuance of the 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 conducting the
EAS Fuel Pier Repair in Alcan Harbor on Shemya Island, Alaska that
includes the previously explained mitigation, monitoring, and reporting
requirements.
Dated: April 22, 2025.
Catherine Marzin,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2025-07168 Filed 4-24-25; 8:45 am]
BILLING CODE 3510-22-P
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</html>Indexed from Federal Register on April 25, 2025.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.