Notice2024-00622
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Pile Driving and Removal To Improve the Auke Bay East Ferry Terminal
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
January 16, 2024
Effective
October 1, 2024
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 Alaska Department of Transportation and Public Facilities (ADOT&PF) to incidentally harass, by Level A and Level B harassment, marine mammals during construction activities associated with a pile driving project for improvements to the Auke Bay East Ferry Terminal in Juneau, Alaska.
Full Text
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<title>Federal Register, Volume 89 Issue 10 (Tuesday, January 16, 2024)</title>
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[Federal Register Volume 89, Number 10 (Tuesday, January 16, 2024)]
[Notices]
[Pages 2584-2598]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-00622]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XC959]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Pile Driving and Removal To Improve
the Auke Bay East Ferry Terminal
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
Alaska Department of Transportation and Public Facilities (ADOT&PF) to
incidentally harass, by Level A and Level B harassment, marine mammals
during construction activities associated with a pile driving project
for improvements to the Auke Bay East Ferry Terminal in Juneau, Alaska.
DATES: This authorization is effective from October 1, 2024 through
September 30, 2025.
ADDRESSES: Electronic copies of the application and supporting
documents, as well as a list of the references cited in this document,
may be obtained online at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-alaska-department-transportation-pile-driving-and-removal">https://www.fisheries.noaa.gov/action/incidental-take-authorization-alaska-department-transportation-pile-driving-and-removal</a>. In case of problems accessing these documents,
please call the contact listed above.
FOR FURTHER INFORMATION CONTACT: Craig Cockrell, 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
[[Page 2585]]
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 or, if the taking
is limited to harassment, a notice of a issued IHA is provided to the
public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
Summary of Request
On September 13, 2022, NMFS received a request from ADOT&PF for an
IHA to take marine mammals incidental to vibratory and impact pile
driving to improve the Auke Bay East Ferry Terminal. Following NMFS'
review of the application, ADOT&PF submitted a revised version on
January 11, 2023. The application was deemed adequate and complete on
February 14, 2023. NMFS published the proposed IHA on April 13, 2023
(88 FR 22411). The ADOT&PF's request is for the incidental take of
small numbers of 11 species or stocks of marine mammals, in the form of
Level B harassment and, for harbor seals (Phoca vitulina) and harbor
porpoise (Phocoena phocoena), including take by Level A harassment.
Neither ADOT&PF nor NMFS expect serious injury or mortality to result
from this activity and, therefore, an IHA is appropriate.
Description of Activity
Overview
ADOT&PF is completing improvements to the existing Alaska Marine
Highway System (AMHS) Auke Bay East Berth marine terminal. The activity
includes removal of existing piles and the installation of both
temporary and permanent piles of various sizes and materials. A total
of 143 piles will be either removed or installed. Takes of marine
mammals by Level A and Level B harassment will occur due to both impact
installation and vibratory pile installation and removal. The project
will occur in Auke Bay, Alaska which is located in southeast Alaska in
close proximity to the city of Juneau. Construction activities are
expected to over a four month period in fall 2023. It is expected to
take up to 61 nonconsecutive days to complete the in-water pile driving
activities.
A detailed description of the planned construction project is
provided in the Federal Register notice for the proposed IHA (88 FR
22411, April 13, 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 Response
A notice of NMFS' proposal to issue an IHA to ADOT&PF was published
in the Federal Register on April 13, 2023 (88 FR 22411). That notice
described, in detail, ADOT&PF's activities, the marine mammal species
that may be affected by the activities, 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. This proposed notice was available for a 30-
day public comment period.
NMFS received one comment from the general public. This comment was
not related to the activity described in the notice and is not
discussed further.
Changes From Proposed IHA to Final IHA
Several changes have been made to the Final IHA. These changes are
summarized below and also identified, and expanded upon as necessary,
in the associated sections of the notice below. In the Proposed IHA the
extent of the Level B harassment zone for vibratory installation and
removal of 24 in. steel piles was inadvertently combined with 18 in.
steel pipe piles. Table 6 has been modified to include the correct size
of the Level B harassment zone size for the vibratory installation and
removal of 24 in. steel piles. The Level A and Level B harassment zones
for 18 in. steel pipe piles were not calculated correctly in the
Proposed IHA. Table 6 has been updated, and Level A and Level B
harassment zones for vibratory installation and removal of the existing
18 in. steel pipe piles have been corrected.
As a result of our consultation under Section 7 of the ESA with the
NMFS Alaska Regional Office, NMFS has revised the source levels for
vibratory driving of 24 in. and 30 inch steel piles. In the Proposed
IHA, 159 and 154 dB RMS re 1[micro]Pa were the selected source values
for 30 in. and 24 in. steel pipe pile driving, respectively (Caltrans
2020). During the comment period for the Proposed IHA, NFMS determined
that measured values from a previous project in Auke Bay and other
sites with similar geology were more appropriate than the proposed
values. Based on this information NMFS has revised our analysis to use
source proxy values of 168.8 from Denes et al. (2016) and 163 dB RMS re
1[micro]Pa (NMFS 2023 analysis \1\) for vibratory driving of 30 in. and
24 in. steel pipe piles, respectively. Denes et al. (2016) measured a
spreading loss coefficient (TL) of 16.4 for 30 in. piles, which NMFS
has applied in the harassment zone calculations. These values increase
the size of the harassment zones, shutdown zones, and monitoring zones
for this project (table 6, 8, and 9). Due to the larger estimated
harassment zones, NMFS has increased the level of take by Level B
harassment for some marine mammal species (table 7). No increase in
Level A take occurred based on this new analysis because the ADOT&PF
has agreed to implement shut down zones larger than the expected Level
A harassment zones. The larger shutdown and monitoring zones do not
require any changes to the other subsequent mitigation, monitoring, or
reporting measures from Proposed IHA, and thus there have been no
changes to the mitigation, monitoring, and reporting sections in this
Notice.
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\1\ Averaged values from Navy (2012, 2013) and Miner (2020).
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Since the Federal Register notice of the proposed IHA was published
(April 13, 2023, 88 FR 22411), NMFS published the final 2022 Alaska and
Pacific Stock Assessment Reports (SARs), which describe revised stock
structures under the MMPA for humpback whales and southeast Alaska
harbor porpoise (Carretta et al., 2023; Young et al., 2023). In the
notice of proposed IHA, we explained that although we typically
consider updated peer-reviewed data provided in draft SARs to be the
best available science, and use the information accordingly, we make
exception for proposed revised stock structures. Upon finalization of
these revised stock structures, we have
[[Page 2586]]
made appropriate updates, including description of the potentially
affected stocks (see table 1), attribution of take numbers to stock
(see Estimated Take), and by updating our analyses to ensure the
necessary determinations are made for the new stocks (see Negligible
Impact Analysis and Determination and Small Numbers).
There was also a clerical error in the calculation of the
percentage of humpback whales from each respective DPS. The Proposed
IHA used 2.4 percent as the estimated percentage of Mexico DPS humpback
whales present in Southeast Alaska. This was revised to 2 percent in
this notice and the numbers of take from each DPS were revised
accordingly (see Estimated Take).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the IHA 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, incorporated here by reference,
instead of reprinting the information. Additional information regarding
population trends and threats may be found in NMFS' SARs;
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a> and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS'
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
All values presented in table 1 are the most recent available at
the time of publication (including from the draft 2022 SARs) and are
available online at: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>).
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\
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Family Balaenopteridae (rorquals):
Humpback whale.................. Megaptera novaeangliae. Hawai[revaps]i......... -, -, N 11,278 (0.56, 7,265, 127 27.09
2020).
Mexico-North Pacific... T, D, Y 918 (0.217, UNK, 2006) UND 0.57
Minke whale..................... Balaenoptera Alaska................. -/-; N N/A (N/A, N/A, N/A)... UND 0
acutorostrada.
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Killer whale.................... Orcinus orca........... Alaska Resident........ -/-; N 1,920 (N/A, 1,920, 19 1.3
2019).
West Coast Transient... -/-; N 349 (N/A, 349, 2018).. 3.5 0.4
Pacific white-sided dolphin..... Lagenorhynchus North Pacific.......... -/-; N 26,880 (N/A, N/A, UND 0
obliquidens. 1990).
Family Phocoenidae (porpoises):
Harbor Porpoise................. Phocoena phocoena...... Northern Southeast -, -, N 1,619 (0.26, 1,250, 13 5.6
Alaska Inland Waters. 2019).
Dall's porpoise................. Phocoenoides dalli..... Alaska................. -/-; N UND (UND, UND, 2015).. UND 37
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Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
sea lions):
Steller sea lion................ Eumetopias jubatus..... Eastern DPS............ -/-; N 43,201 (N/A, 43,201, 2,592 112
2017).
Western DPS............ E/D; Y 52,932 (N/A, 53,932, 318 254
2019).
California sea lion............. Zalophus californianus. U.S.................... -/-; N 257,606 (N/A, 233,515, 14,011 >321
2014).
Northern fur seal............... Callorhinus ursinus.... Eastern Pacific........ -/-; Y 626,618 (0.2, 530,376, 11,403 373
2019).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... Lynn Canal/Stephens -/-; N 13,388 (N/A, 11,867, 214 50
Passage. 2016).
Northern Elephant Seal.......... Mirounga angustirostris California............. -/-; N 187,386 (N/A, 85,369, 5,122 13.7
2013).
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\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="http://www.nmfs.noaa.gov/pr/sars/">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, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
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
[[Page 2587]]
(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.). 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 ADOT&PF's construction
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the survey area. The notice of
proposed IHA (88 FR 22411, April 13, 2023) included a discussion of the
effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from ADOT&PF's 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 22411, April 13, 2023).
Estimated Take
This section provides an estimate of the number of incidental takes
for the authorization 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. Authorized takes will primarily be by Level B harassment,
as use of the acoustic sources (i.e., impact and vibratory pile
driving) has the potential to result in disruption of behavioral
patterns for individual marine mammals. There is also some potential
for auditory injury (Level A harassment) to result, primarily for high
frequency cetaceans and phocids because predicted auditory injury zones
are larger than for other hearing groups. Auditory injury is unlikely
to occur for other groups. The mitigation and monitoring measures are
expected to minimize the severity of the taking to the extent
practicable.
As described in the proposed notice (88 FR 22411, April 13, 2023),
no serious injury or mortality is anticipated or authorized for this
activity. Below we describe how the take numbers are estimated. As
noted in the Changes from Proposed IHA to Final IHA section some of the
harassment and monitoring zones have changed as well as the estimated
take number for some marine mammal species.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic thresholds above which NMFS believes the best
available science indicates marine mammals will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
will be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur permanent threshold shift (PTS) of some
degree (equated to Level A harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic
[[Page 2588]]
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 (root mean square (RMS) sound
pressure level (SPL)) of 120 dB (referenced to 1 micropascal (re 1
microPascal ([mu]Pa)) for continuous (e.g., vibratory pile-driving) and
above RMS SPL 160 dB re 1 [mu]Pa for non-explosive impulsive (e.g.,
seismic airguns, impact pile driving) or intermittent (e.g., scientific
sonar) sources. Generally speaking, Level B harassment take estimates
based on these behavioral harassment thresholds are expected to include
any likely takes by temporary threshold shifts (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 will not otherwise occur.
ADOT&PF's activity includes the use of continuous (vibratory pile
installation and removal) and impulsive (impact pile driving) sources,
and therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa 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). ADOT&PF's
activity includes the use of impulsive (impact pile driving) and non-
impulsive (vibratory pile driving and removal) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 3--Onset of Permanent Threshold Shift (PTS)
[NMFS 2018]
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: L0-pk,flat: 219 Cell 2: LE, LF,24h: 199 dB.
dB; LE, LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: L0-pk,flat: 230 Cell 4: LE, MF,24h: 198 dB.
dB; LE, MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: L0-pk,flat: 202 Cell 6: LE, HF,24h: 173 dB.
dB; LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: L0-pk.flat: 218 Cell 8: LE,PW,24h: 201 dB.
dB; LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: L0-pk,flat: 232 Cell 10: LE,OW,24h: 219 dB.
dB; LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric 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 are recommended for consideration.
Note: Peak sound pressure level (L0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,) has a reference value of 1[micro]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 160 kHz). 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 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 project. Marine
mammals are expected to be affected via sound generated by the primary
components of the project (i.e., impact pile driving, vibratory pile
driving and removal). The maximum (underwater) area ensonified above
the thresholds for behavioral harassment referenced above is 30.7 km\2\
(11.9 mi\2\), and is governed by the topography of Auke Bay and the
various islands located within and around the bay. This underwater area
has increased from the proposed IHA due to the higher source level for
30 inch piles (168.8 dB RMS re 1[micro]Pa) anticipated in Auke Bay. The
eastern part of Auke Bay is acoustically shadowed by Auke Cape, Coghlan
Island, and Suedla Island, and will inhibit sound transmission from
reaching the more open waters toward Spuhn Island (see Figure 6-2 in
the IHA application). Additionally, vessel traffic and other commercial
and industrial activities in the project area may contribute to
elevated background noise levels which may mask sounds produced by the
project.
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 * Log<INF>10</INF> (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
This formula neglects loss due to scattering and absorption, which
is assumed to be zero here. The degree to which underwater sound
propagates away from a sound source is dependent on a variety of
factors, most notably the water bathymetry and presence or absence of
reflective or absorptive
[[Page 2589]]
conditions including in-water structures and sediments. Spherical
spreading occurs in a perfectly unobstructed (free-field) environment
not limited by depth or water surface, resulting in a 6 dB reduction in
sound level for each doubling of distance from the source
(20*log<INF>10</INF>[range]). Cylindrical spreading occurs in an
environment in which sound propagation is bounded by the water surface
and sea bottom, resulting in a reduction of 3 dB in sound level for
each doubling of distance from the source (10*log<INF>10</INF>[range]).
A practical spreading value of 15 is often used under conditions, such
as the project site, where water increases with depth as the receiver
moves away from the shoreline, resulting in an expected propagation
environment that will lie between spherical and cylindrical spreading
loss conditions. Transmission loss can be measured in the field for
specific sites and activities.
Since the proposed IHA was published, NMFS identified site-specific
spreading loss data that are applicable to Auke Bay. Specifically,
Denes et al. (2016) measured a spreading loss coefficient of 16.4
during the previous monitoring of vibratory installation of 30-in steel
pipe piles in Auke Bay. This value is applicable for the current
analysis, and we have therefore used TL = 16.4 for determining the
harassment zones for vibratory installation of 30 inch steel pipe
piles. For all other planned pile types and driving methods, there are
no available site-specific TL measurements. NMFS has therefore used the
default practical spreading model (TL = 15) in analysis of all other
pile types for this project.
The intensity of pile driving sounds is greatly influenced by
factors such as the type of piles, hammers, and the physical
environment in which the activity takes place. In order to calculate
the distances to the Level A harassment and the Level B harassment
thresholds for the methods and piles being used in this project, NMFS
used acoustic monitoring data from other locations to develop proxy
source levels for the various pile types, sizes and methods. The
project includes vibratory and impact pile installation and vibratory
removal of steel pipe piles. Proxy source levels for each pile size and
driving method are presented in table 4. The source levels for
vibratory and impact installation of all pile sizes are based on
measured values from similar types of piles reported in the following
sources: California Department of Transportation (Caltrans) in pile
driving source level compendium documents (Caltrans, 2015 and 2020);
Denes et al. (2016), and mean values for other regionally relevant
reports compiled by NMFS (table 4).
Table 4--Proxy Sound Source Levels for Pile Sizes and Driving Methods
--------------------------------------------------------------------------------------------------------------------------------------------------------
Proxy source level
---------------------------------------------------------
Pile size Method dB RMS re dB SEL re dB peak re Literature source
1[micro]Pa 1[micro]Pa\2\sec 1[micro]Pa
--------------------------------------------------------------------------------------------------------------------------------------------------------
30 in................................. Vibratory............... * 168.8 N/A N/A Denes et al. 2016.
24 in................................. Vibratory............... * 163 N/A N/A NMFS 2023 analysis.**
18 in................................. Vibratory............... 158 N/A N/A Caltrans 2020.
30 in................................. Impact.................. 190 177 210 Caltrans 2015, 2020.
24 in................................. Impact.................. 190 177 203 Caltrans 2015, 2020.
18 in................................. Impact.................. 185 175 200 Caltrans 2015, 2020.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Source levels for vibratory pile installation and removal from the proposed IHA for 30 in. and 24 in. piles were 159 dB RMS re 1[micro]Pa and 154 dB
RMS re 1[micro]Pa respectively.
** Navy (2012, 2013) and Miner (2020); averaging methodology followed Navy (2015).
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 impact or vibratory pile driving and
removal, the optional User Spreadsheet tool predicts the distance at
which, if a marine mammal remained at that distance for the duration of
the activity, it will be expected to incur PTS. Inputs used in the
optional User Spreadsheet tool (table 5), and the resulting estimated
isopleths and the calculated Level B harassment isopleth (table 6), are
reported below. For source levels of each pile please refer to table 4.
For impact installation of piles, the harassment zones were
calculated based on the number of piles to be installed per day.
ADOT&PF provided a range of one to four piles per day for impact
installation for all pile sizes. This was done to account for more
efficient days of pile installation as not to limit construction
activity on those days. If more piles per day are installed it is
likely to reduce the number of days impact installation will occur.
[[Page 2590]]
Table 5--User Spreadsheet Input Parameters Used for Calculating Level A Harassment Isopleths
----------------------------------------------------------------------------------------------------------------
Weighting
Pile size and installation Spreadsheet tab factor Number of Number of Activity
method used adjustment strikes per piles per day duration
(kHz) pile (minutes)
----------------------------------------------------------------------------------------------------------------
30 in vibratory installation.. A.1 Vibratory 2.5 N/A 3 60
pile driving.
24 in vibratory installation.. A.1 Vibratory 2.5 N/A 3 60
pile driving.
24 in vibratory installation A.1 Vibratory 2.5 N/A 3 30
(temporary). pile driving.
24 in vibratory removal A.1 Vibratory 2.5 N/A 3 60
(temporary). pile driving.
18 in vibratory installation.. A.1 Vibratory 2.5 N/A 3 60
pile driving.
18 in vibratory removal A.1 Vibratory 2.5 N/A 3 30
(existing). pile driving.
30 in impact installation..... E.1 Impact pile 2 1,000 1-4 N/A
driving.
24 in impact installation..... E.1 Impact pile 2 1,000 1-4 N/A
driving.
24 in impact installation..... E.1 Impact pile 2 500 1-4 N/A
driving.
18 in impact installation..... E.1 Impact pile 2 800 1-4 N/A
driving.
----------------------------------------------------------------------------------------------------------------
Table 6--Calculated Level A and Level B Harassment Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A harassment zone (m) Level B
Activity -------------------------------------------------------------------------------- harassment
LF-cetaceans MF-cetaceans HF-cetaceans Phocids Otariids zone (m)
--------------------------------------------------------------------------------------------------------------------------------------------------------
30 in vibratory installation............................ 41 (11) 5 (1) 59 (16) 26 (7) 2 (1) * 9,454
24 in vibratory installation............................ 19 (5) 2 (1) 29 (8) 12 (3) 1 (1) * 7,356
24 in vibratory installation (temporary)................ 12 (4) 1 (1) 18 (5) 7 (2) 1 (1)
24 in vibratory removal (temporary)..................... 19 (5) 2 (1) 29 (8) 12 (3) 1 (1)
18 in vibratory installation............................ 9 1 14 6 1 * 3,415
18 in vibratory removal (existing)...................... 6 (9) 1 (1) 8 (14) 3 (6) 1 (1)
30 in impact installation (4 piles per day; 1,000 1,002 36 1,194 537 39 1,000
strikes per pile)......................................
30 in impact installation (3 piles per day; 1,000 827 30 985 443 33
strikes per pile)......................................
30 in impact installation (2 piles per day; 1,000 632 23 752 338 25
strikes per pile)......................................
30 in impact installation (1 pile per day; 1,000 strikes 398 15 474 213 16
per pile)..............................................
24 in impact installation (4 piles per day; 1,000 1,002 36 1,194 537 39 1,000
strikes per pile)......................................
24 in impact installation (3 piles per day; 1,000 827 30 985 443 33
strikes per pile)......................................
24 in impact installation (2 piles per day; 1,000 632 23 752 338 25
strikes per pile)......................................
24 in impact installation (1 pile per day; 1,000 strikes 398 15 474 213 16
per pile)..............................................
24 in impact installation (4 piles per day; 500 strikes 632 23 752 338 25
per pile)..............................................
24 in impact installation (3 piles per day; 500 strikes 521 19 621 279 21
per pile)..............................................
24 in impact installation (2 piles per day; 500 strikes 398 15 474 213 16
per pile)..............................................
24 in impact installation (1 pile per day; 500 strikes 251 9 299 134 10
per pile)..............................................
18 in impact installation (4 piles per day; 800 strikes 636 23 757 340 25 464
per pile)..............................................
18 in impact installation (3 piles per day; 800 strikes 525 19 625 281 21
per pile)..............................................
18 in impact installation (2 piles per day; 800 strikes 401 15 477 215 16
per pile)..............................................
18 in impact installation (1 pile per day; 800 strikes 252 9 301 135 10
per pile)..............................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
* The Proposed IHA ((88 FR 22411, April 13, 2023) harassment zones for vibratory installation and removal for 30 in., 24 in., and 18 in. steel pipe
piles were 3,981, 1,848, and 1,848 respectively.
Marine Mammal Occurrence and Take Estimation
In this section, we provide information about the occurrence of
marine mammals, including density or other relevant information that
will inform the take calculations. As described above, since the
proposed IHA, changes have been made to some of the harassment zones.
These changes have resulted in changes to the amount of Level B
harassment authorized for all species, with the exception of the four
species that are rarely encountered (minke whales, California sea
lions, Northern fur seals, and Northern elephant seals). The changes
are
[[Page 2591]]
described in the sections below and reflected in table 7.
When available, peer-reviewed scientific publications were used to
estimate marine mammal abundance in the project area. Data from
monitoring reports from previous projects on the Auke Bay Ferry
Terminal were used as well as reports from other projects in Juneau,
Alaska. However, scientific surveys and resulting data, such as
population estimates, densities, and other quantitative information,
are lacking for some marine mammal populations and most areas of
southeast Alaska, including Auke Bay. Therefore, AKDOT&PF gathered
qualitative information from discussions with knowledgeable local
people in the Auke Bay area.
Here we describe how the information provided is synthesized to
produce a quantitative estimate of the take that is reasonably likely
to occur and authorized for authorization. Since reliable densities are
not available, the applicant requests take based on the maximum number
of animals that may occur in the harbor in a specified measure of time
multiplied by the total duration of the activity.
Humpback Whale
Use of Auke Bay by humpback whales is intermittent and irregular
year-round. During winter, researchers have documented 1 to 19
individual humpback whales per month in waters close to the project
area, including Lynn Canal (Moran et al., 2018a; Straley et al., 2018).
Group sizes in southeast Alaska generally range from one to four
individuals (Dahlheim et al., 2009). In the Proposed IHA NMFS predicted
that two groups of two humpback whales could be exposed to Level B
harassment during each day of the 61 days of work for a total of 244
animals. After revising the Level B harassment zones for 30 inch and 24
inch steel pipe piles, NMFS noted that the entrance to Fritz Cove is
part of the new ensonified area during vibratory driving of 24-in and
30-in. piles. During winter, Fritz Cove is a known aggregation area for
humpback whales. Thus, NMFS expects that an additional two groups of
two could occur during pile driving activities for a total of 488
animals (Wright, S., pers. comm.). As described previously, 2 percent
of the humpback whales in Southeast Alaska are members of the Mexico
distinct population segment (DPS), and therefore 10 animals will be
Mexico DPS individuals and the remaining 478 animals will be Hawaii DPS
individuals.
The largest Level A shutdown zone for humpback whales extends 1,002
meters from the noise source (table 6), and will occur only on days
when impact driving of four 30 in. or 24 in. piles are expected. All
construction work will be shut down prior to a humpback whale entering
the Level A zone specific to the in-water activity underway at the
time. No take by Level A harassment was requested and none is
authorized for humpback whales.
Minke Whales
Dedicated surveys for cetaceans in southeast Alaska found that
minke whales were scattered throughout inland waters from Glacier Bay
and Icy Strait to Clarence Strait, with small concentrations near the
entrance of Glacier Bay. All sightings were of single minke whales,
except for a single sighting of multiple minke whales. Surveys took
place in spring, summer, and fall, and minke whales were present in low
numbers in all seasons and years (Dahlheim et al., 2009). Although
minke whales are rarely occur in the project area NMFS is authorizing
take of one minke whale per month by Level B harassment for a total of
four takes over the course of the project.
The Level A harassment zones and shutdown protocols for minke
whales are the same as for humpback whales. Therefore, given the low
occurrence of minke whales combined with the mitigation, takes by Level
A harassment have not been requested and are not authorized.
Killer Whale
Killer whales are observed occasionally during summer throughout
Lynn Canal, but their presence in Auke Bay is unlikely. In the Proposed
IHA NMFS expected one killer whale resident pod and one transient pod
to be taken by Level B harassment. Since the expansion of the new Level
B harassment zone for vibratory pile driving activities now extends out
into the open waters of the Stephens Passage, NMFS is authorizing two
killer whale resident pods and two transient pods to be taken by Level
B harassment. Group sizes for resident and transient pods are likely to
be 14 and 44 animals, respectively, which will result in 28 and 88
animals taken by level B harassment over the course of the project
(Dahlheim et al., 2009).
ADOT&PF will implement shutdown zones that encompass the largest
Level A harassment zones for killer whales during all pile driving
activities. Killer whales are generally conspicuous and protected
species observers (PSOs) are expected to detect killer whales and
implement a shutdown before the animals enter the Level A harassment
zone. Therefore, takes by Level A harassment have not been requested
and are not authorized.
Pacific White-Sided Dolphins
Based on occurrence data ADOT&PF requested a total of 92 takes by
Level B harassment (the median group size observed in aerial surveys;
range from 20 to 164 individuals) (Muto et al. 2022). NMFS proposed
this take level by Level B harassment based on one group of Pacific
white-sided dolphins to occur over the duration of the project. Similar
to killer whales, NMFS is authorizing higher take levels of Pacific
white-sided dolphins by Level B harassment due to the larger harassment
zone. NMFS expects two groups of 92 to occur during construction
activities resulting in a total of 184 takes by Level B harassment.
The largest Level A harassment zone for Pacific white-sided
dolphins extends 36 m from the source during impact installation of 30-
in piles (table 6). Pacific white-sided dolphins are expected to be
seen by PSOs before entering this zone and shutdown of activity will
occur. No take by Level A harassment is authorized or anticipated.
Harbor Porpoise
Initially ADOT&PF requested a total of 122 takes of harbor porpoise
over the course of the 61 day project. ADOT&PF estimated that 25
percent of those takes could be Level A exposures which would equate to
30 over the project duration. After further review of previous
monitoring results, including unpublished data (Wright, S., pers.
comm.), NMFS proposed authorization of four animals per day in the
Proposed IHA, equating to 244 takes of harbor porpoise by Level A and
Level B harassment.
Given the larger Level B harassment zone, NMFS now expects an
additional 56 takes by Level B harassment. This was calculated by
doubling the estimated abundance of this species for the 14 days of
vibratory driving of 30 inch piles. NMFS determined that increasing the
take in proportion to the increased area ensonified was not justified
because harbor porpoise tend to inhabit coastal shallow water and the
new harassment zone does not encompass a substantial amount of new
shoreline compared to the initial proposed harassment zone. The total
number of takes by Level B harassment authorized is 300. NMFS has not
increased the authorized takes by Level A harassment because the
increases in Level A harassment zones expected during vibratory driving
of 24-in and 30-in steel pipe piles are minimal and the
[[Page 2592]]
applicant has agreed to increase the size of the shutdown zone for this
species during these activities to encompass the increased Level A
isopleths.
Harbor porpoises are known to be an inconspicuous species and are
challenging for protected species observers (PSOs) to sight, making any
approach to a specific area potentially difficult to detect. Because
harbor porpoises move quickly and elusively, it is possible that they
may enter the Level A harassment zone without detection. The largest
Level A harassment zone results from impact driving of 30-in piles, and
extends 1,194 m from the source for high frequency cetaceans (table 6).
ADOT&PF will implement a shutdown zone for harbor porpoises that
encompasses the largest Level A harassment zone (see Mitigation
section) but given the sighting challenges for PSOs some take by Level
A harassment is expected during impact pile driving.
Dall's Porpoise
No systematic studies of Dall's porpoise abundance or distribution
have occurred in Auke Bay; however, Dall's porpoises have been
consistently observed in Lynn Canal, Stephens Passage, upper Chatham
Strait, Frederick Sound, and Clarence Strait (Dalheim et al., 2000).
ADOT&PF initially requested take of one group of 20 animals per month
in the project area for a total of 80 takes by Level B harassment.
After reviewing ADOT&PF's monitoring results from Auke Bay in 2021, one
lone Dall's porpoise was sighted. Thus, the Proposed IHA included a
conservative estimate of two groups of five animals per month, giving a
maximum of 30 takes by Level B harassment throughout the course of the
project. With the increase in the Level B harassment zones NMFS expects
one additional group of 5 for a total of 35 takes by Level B
harassment.
ADOT&PF will implement shutdown zones for porpoises that encompass
the largest Level A harassment zones for each pile driving activity
(see Mitigation section). The largest Level A harassment zone for
Dall's porpoise extends 1,194 m from the source during impact
installation of 30-in piles (table 6). Given the more conspicuous
rooster-tail generated by swimming Dall's porpoises, which makes them
more noticeable than harbor porpoises, PSOs are expected to detect
Dall's porpoises prior to them entering the Level A harassment zone
(Jefferson 2009). Therefore, takes of Dall's porpoises by Level A
harassment have not been requested and are not authorized.
Steller Sea Lion
Based on recent monitoring reports for Auke Bay Ferry Terminal and
Statter Harbor projects (2021 and 2019) it is estimated that groups of
up to 50 animals per day could be exposed to underwater noise. The
Proposed IHA predicted a total of 3,050 exposures to sound levels at or
above the Level B harassment threshold could occur over the 61 days of
construction. Steller sea lions have similar habitat usage pattern as
humpback whales in Fritz Cove. Therefore, NMFS is increasing the number
of takes to 6,100. Given the 1.4 percent of Steller sea lions belong to
the western DPS (wDPS) in Auke Bay, 86 total exposures are expected
from the wDPS and the remaining 6,015 exposures of eastern DPS Steller
sea lions.
The largest Level A harassment zone for otariid pinnipeds extends
39 m from the source (table 6). ADOT&PF is planning to implement a
larger shutdown zones than the Level A harassment zones during all pile
installation and removal activities (see Mitigation section), which is
expected to eliminate the potential for take by Level A harassment of
Steller sea lions. Therefore, no takes of Steller sea lions by Level A
harassment were requested or are authorized.
California Sea Lion
California sea lions rarely occur in the project area. In 2017, a
lone California sea lion was spotted in the harbor. Recently,
monitoring reports from similar construction projects did not observe
any California sea lions in Auke Bay. Based on the sighting from 2017,
ADOT&PF is estimating one animal per day of construction which will
equate to 61 takes by Level B harassment.
The largest Level A harassment zone for otariid pinnipeds extends
39 m from the source (table 6). ADOT&PF is planning to implement larger
shutdown zones than the Level A harassment zones during all pile
installation and removal activities (see Mitigation section), which is
expected to eliminate the potential for take by Level A harassment of
California sea lions. Therefore, no takes of California sea lions by
Level A harassment were requested or are authorized.
Northern Fur Seal
Although take of Northern fur seal was not requested by ADOT&PF,
NMFS recommended the inclusion of Northern fur seals in the take
estimation. We estimate that up to five northern fur seals may be
present in the action area per month which may result in 15 takes by
Level B harassment over the course of the project.
The largest Level A harassment zone for otariid pinnipeds extends
39 m from the source (table 6). ADOT&PF is planning to implement larger
shutdown zones than the Level A harassment zones during all pile
installation and removal activities (see Mitigation section), which is
expected to eliminate the potential for take by Level A harassment of
Northern fur seals. Therefore, no takes of Northern fur seals by Level
A harassment were requested or are authorized.
Harbor Seal
In the Proposed IHA, NMFS based take estimates on the monitoring
results of ADOT&PF's 2021 project in Auke Bay. It was expected that 50
harbor seals per day could be taken during the 61 days of construction
(AKDOT&PF, 2021). NMFS proposed 3,050 takes of harbor seals by Level B
harassment for the duration of the project. Similar to harbor porpoise,
harbor seals typically inhabit costal inland waters. Given the larger
Level B harassment zones NMFS expects, an additional 447 takes by Level
B harassment over the 14 day of vibratory installation of 30-in piles
are estimated. NMFS is authorizing 3,752 takes by Level B harassment
for the duration of the project. NMFS has not increased the authorized
takes by Level A harassment because the increases in Level A harassment
zones expected during vibratory driving of 24-in and 30-in steel pipe
piles are minimal and the applicant has agreed to increase the size of
the shutdown zones for this species during these activities to
encompass the increased Level A isopleths.
The largest Level A harassment zone for phocid pinnipeds results
from impact pile driving of 30-in piles and extends 537 m from the
source (table 6). There are no haulouts located within the Level A
harassment zone and although it is unlikely, it is possible that harbor
seals may approach and enter the Level A harassment zone undetected.
Two harbor seals are estimated to approach the site within 537 m of the
source each day. Impact pile driving may occur on up to 34 days (table
1). For this reason, we propose take by Level A harassment of two
harbor seals daily on the 34 days of impact pile driving for a total of
68 takes by Level A harassment. The largest Level A harassment zone for
phocid pinnipeds from vibratory pile driving extends 30 m from the
source (table 6). ADOT&PF is planning to implement larger shutdown
zones than the Level A harassment zones during all pile installation
and removal activities (see Mitigation
[[Page 2593]]
section), which is expected to eliminate the potential for Level A
harassment of harbor seals from vibratory pile driving.
Northern Elephant Seal
Given the increase in population size and sightings throughout
Southeast Alaska ADOT&PF requested one elephant seal take per week. The
project is expected to take up to 16 weeks to complete which will
equate to 16 takes by Level B harassment.
The largest Level A harassment zone for phocid pinnipeds extends
537 m from the source (table 6). ADOT&PF is planning to implement
larger shutdown zones than the Level A harassment zones during all pile
installation and removal activities (see Mitigation section), which is
expected to eliminate the potential for take by Level A harassment of
elephant seals. Therefore, no takes of elephant seals by Level A
harassment were requested or are authorized.
Table 7--Authorized Take by Level A and Level B Harassment, by Species and Stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Proposed IHA Final IHA authorized take
Stock -----------------------------------------------------------------
Common name Stock abundance Total Take as
\a\ proposed Level A Level B Total take percentage
take harassment harassment of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale............................ Hawai[revaps]i............... 11,278 238 0 476 476 4.2
Mexico-North Pacific......... 918 6 0 10 10 1.1
Minke whale............................... Alaska....................... N/A 4 0 4 4 N/A
Killer Whale.............................. Alaska Resident.............. 1,920 41 0 82 82 4.3
West Coast Transient......... 349 14 0 28 28 8.0
Pacific white-sided dolphin............... North Pacific................ 931,000 92 0 184 184 0.02
Harbor porpoise........................... Northern Southeast Alaska.... 1,619 244 61 300 361 22.3
Dall's porpoise........................... Alaska....................... 83,400 30 0 35 35 0.04
Steller sea lion.......................... Eastern U.S.................. 43,201 3,008 0 6,015 6,015 13.9
Western U.S.................. 52,932 43 0 86 86 0.16
California sea lion....................... U.S.......................... 257,606 61 0 61 61 0.02
Northern fur seal......................... Eastern Pacific.............. 626,618 15 0 15 15 <0.01
Harbor seal............................... Lynn Canal/Stephens Passage.. 13,388 3,050 68 3,752 3,820 28.5
Northern Elephant Seal.................... California................... 187,386 16 0 16 16 <0.01
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Stock or DPS size is Nbest according to NMFS 2022 Final Stock Assessment Reports.
Mitigation Measures
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. NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned), and;
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations.
In addition to the measures described later in this section,
ADOT&PF will employ the following standard mitigation measures:
<bullet> At the start of each day, the Contractor(s) will hold a
briefing with the Lead PSO to outline the activities planned for that
day.
<bullet> If poor weather conditions restrict the PSO's ability to
make observations within the Level A and B harassment zone of pile
driving (e.g., if there is excessive wind or fog), pile installation
and removal will be halted.
The following measures will apply to ADOT&PF's mitigation
requirements:
Implementation of Shutdown Zones for Level A Harassment--For all
pile driving/removal activities, ADOT&PF will implement shutdowns
within designated zones. The purpose of a shutdown zone is generally to
define an area within which shutdown of activity will occur upon
sighting of a marine mammal (or in anticipation of an animal entering
the defined area). Implementation of shutdowns will be used to avoid or
minimize incidental Level A harassment exposures from vibratory and
impact pile driving for all 11 species for which take may occur (see
table 7). ADOT&PF has voluntarily implemented a minimum shutdown zone
of 30 m during all pile driving and removal activities (table 8).
Shutdown zones for impact pile driving activities are based on the
Level A harassment zones and therefore vary by pile size, number of
piles installed per day, and marine mammal hearing group (table 8).
Shutdown zones for impact pile driving will be established each day for
the greatest number of piles that are expected to be installed that
day. The placement of PSOs during all pile driving activities
(described in detail in the Monitoring and Reporting Section) will
ensure the full extent of shutdown zones are visible to PSOs.
[[Page 2594]]
Table 8--Shutdown Zones During Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
Shutdown zones (m)
Piles per ----------------------------------------------------------------
Activity day * LF MF HF
cetaceans cetaceans cetaceans Phocids Otariids
----------------------------------------------------------------------------------------------------------------
All vibratory installation and N/A ** 75 30 ** 75 30 30
removal..........................
30-in impact (1,000 strikes)...... 4 1,100 40 1,200 540 40
3 830 30 990 450
2 640 760 340 30
1 400 480 220
24-in impact (1,000 strikes)...... 4 1,100 40 1,200 540 40
3 830 30 990 450
2 640 760 340 30
1 400 480 220
24-in impact (500 strikes)........ 4 640 30 760 340 30
3 530 630 280
2 400 480 220
1 260 300 140
18-in impact (800 strikes)........ 4 640 30 760 340 30
3 530 630 280
2 400 480 220
1 260 300 140
----------------------------------------------------------------------------------------------------------------
* The applicant will chose the number of piles to be driven in any given day (and therefore the maximum
associated shutdown zone to be implemented that day) before work begins. Shutdown zones may not change for a
given day once implemented.
** Zones that have increased from the Proposed IHA (88 FR 22411, April 13, 2023).
Establishment of Monitoring Zones--ADOT&PF has identified
monitoring zones correlated with the larger of the Level B harassment
or Level A harassment zones. Monitoring zones provide utility for
observing by establishing monitoring protocols for areas adjacent to
the shutdown zones. Monitoring zones enable observers to be aware of
and communicate the presence of marine mammals in the project area
outside the shutdown zone and thus prepare for a potential cease of
activity should the animal enter the shutdown zone. PSOs will monitor
the entire visible area to maintain the best sense of where animals are
moving relative to the zone boundaries defined in tables 8 and 9.
Placement of PSOs on the shorelines around Auke Bay allow PSOs to
observe marine mammals within and near Auke Bay.
Table 9--Marine Mammal Monitoring Zone
------------------------------------------------------------------------
Monitoring
Activity zone (m)
------------------------------------------------------------------------
30-in vibratory installation............................ * 9,454
24-in 18-in vibratory installation and removal.......... * 7,356
18-in vibratory installation and removal................ * 3,415
30-in and 24 in impact installation..................... 1,200
18-in impact installation............................... 760
------------------------------------------------------------------------
* Zones that have increased from the Proposed IHA (88 FR 22411, April
13, 2023).
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
will be required to provide an initial set of 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.
Pre-Activity Monitoring--Prior to the start of daily in-water
construction activity, or whenever a break in pile driving/removal of
30 minutes or longer occurs, PSOs will observe the shutdown and
monitoring zones for a period of 30 minutes. The shutdown zone will be
considered cleared when a marine mammal has not been observed within
the zone for that 30-minute period. If a marine mammal is observed
within the shutdown zone, a soft-start cannot proceed until the animal
has left the zone or has not been observed for 15 minutes. If the
monitoring zone has been observed for 30 minutes and marine mammals are
not present within the zone, soft-start procedures can commence and
work can continue even if visibility becomes impaired within the
monitoring zone. When a marine mammal permitted for take by Level B
harassment is present in the Level B harassment zone, activities may
begin. No work may begin unless the entire shutdown zone is visible to
the PSOs. If work ceases for more than 30 minutes, the pre-activity
monitoring of both the monitoring zone and shutdown zone will commence.
Based on our evaluation of the applicant's mitigation measures,
NMFS has determined that the measures provide the means of effecting
the least practicable impact on the affected species or stocks and
their habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through
[[Page 2595]]
better understanding of: (1) action or environment (e.g., source
characterization, propagation, ambient noise); (2) affected species
(e.g., life history, dive patterns); (3) co-occurrence of marine mammal
species with the activity; or (4) biological or behavioral context of
exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and,
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Monitoring shall be conducted by NMFS-approved observers in
accordance with the monitoring plan and Section 5 of the IHA. Trained
observers shall be placed from the best vantage point(s) practicable to
monitor for marine mammals and implement shutdown or delay procedures
when applicable through communication with the equipment operator.
Observer training must be provided prior to project start, and shall
include instruction on species identification (sufficient to
distinguish the species in the project area), description and
categorization of observed behaviors and interpretation of behaviors
that may be construed as being reactions to the specified activity,
proper completion of data forms, and other basic components of
biological monitoring, including tracking of observed animals or groups
of animals such that repeat sound exposures may be attributed to
individuals (to the extent possible).
Monitoring will be conducted 30 minutes before, during, and 30
minutes after pile driving/removal activities. In addition, observers
shall record all incidents of marine mammal occurrence, regardless of
distance from activity, and shall document any behavioral reactions in
concert with distance from piles being driven or removed. Pile driving/
removal 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.
A minimum of two PSOs will be on duty during all impact
installation and a minimum of three PSOs during vibratory installation/
removal. Locations from which PSOs will be able to monitor for marine
mammals are readily available from publicly accessible shoreside areas
at the Auke Bay East Ferry Terminal and, if necessary, other public and
private points along the Glacier and Douglas highways. Monitoring
locations will be selected by the Contractor during pre-construction.
PSOs will monitor for marine mammals entering the Level B harassment
zones; the position(s) may vary based on construction activity and
location of piles or equipment.
PSOs will scan the waters using binoculars, and/or spotting scopes,
and will use a handheld range-finder device to verify the distance to
each sighting from the project site. All PSOs will be trained in marine
mammal identification and behaviors and are required to have no other
project-related tasks while conducting monitoring. In addition,
monitoring will be conducted by qualified observers, who will be placed
at the best vantage point(s) practicable to monitor for marine mammals
and implement shutdown/delay procedures when applicable by calling for
the shutdown to the hammer operator via a radio. ADOT&PF will adhere to
the following observer qualifications:
(i) Independent observers (i.e., not construction personnel) are
required;
(ii) One PSO will be designated as the lead PSO or monitoring
coordinator and that observer must have prior experience working as an
observer;
(iii) Other observers may substitute education (degree in
biological science or related field) or training for experience; and
(iv) ADOT&PF must submit observer Curriculum Vitaes for approval by
NMFS.
Additional standard observer qualifications include:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates and times when in-water construction
activities were suspended to avoid potential incidental injury from
construction sound of marine mammals observed within a defined shutdown
zone; and marine mammal behavior; and
<bullet> Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving and removal
activities. It will include an overall description of work completed, a
narrative regarding marine mammal sightings, and associated PSO data
sheets. Specifically, the report must include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring.
<bullet> Construction activities occurring during each daily
observation period, including the number and type of piles driven or
removed and by what method (i.e., impact driving) and the total
equipment duration for cutting for each pile or total number of strikes
for each pile (impact driving).
<bullet> PSO locations during marine mammal monitoring.
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance;
<bullet> Upon observation of a marine mammal, the following
information: Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting; Time of sighting; 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; Distance and bearing of each
marine mammal observed relative to the pile being driven for each
sighting (if pile driving was occurring at time of sighting); Estimated
number of animals (min/max/best estimate); Estimated number of animals
by cohort (adults, juveniles, neonates, group composition, etc.);
Animal's closest point of approach and estimated time spent within the
harassment zone; 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
[[Page 2596]]
resulted from the activity (e.g., no response or changes in behavioral
state such as ceasing feeding, changing direction, flushing, or
breaching);
<bullet> Number of marine mammals detected within the harassment
zones, by species.
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensued, and resulting changes in behavior of the
animal(s), if any.
If no comments are received from NMFS within 30 days, the draft
final report will constitute the final report. If comments are
received, a final report addressing NMFS comments must be submitted
within 30 days after receipt of comments.
Reporting Injured or Dead Marine Mammals
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as an injury, serious injury or mortality, ADOT&PF
will immediately cease the specified activities and report the incident
to the Chief of the Permits and Conservation Division, Office of
Protected Resources, NMFS, and the Alaska Regional Stranding
Coordinator. The report will include the following information:
<bullet> Description of the incident;
<bullet> Environmental conditions (e.g., Beaufort sea state,
visibility);
<bullet> Description of all marine mammal observations in the 24
hours preceding the incident;
<bullet> Species identification or description of the animal(s)
involved;
<bullet> Fate of the animal(s); and
<bullet> Photographs or video footage of the animal(s) (if
equipment is available).
Activities will not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS will work with ADOT&PF to
determine what is necessary to minimize the likelihood of further
prohibited take and ensure MMPA compliance. ADOT&PF will not be able to
resume their activities until notified by NMFS via letter, email, or
telephone.
In the event that ADOT&PF discovers an injured or dead marine
mammal, and the lead PSO determines that the cause of the injury or
death is unknown and the death is relatively recent (e.g., in less than
a moderate state of decomposition as described in the next paragraph),
ADOT&PF will immediately report the incident to the Chief of the
Permits and Conservation Division, Office of Protected Resources, NMFS,
and the NMFS Alaska Stranding Hotline and/or by email to the Alaska
Regional Stranding Coordinator. The report will include the same
information identified in the paragraph above. Activities will be able
to continue while NMFS reviews the circumstances of the incident. NMFS
will work with ADOT&PF to determine whether modifications in the
activities are appropriate.
In the event that ADOT&PF discovers an injured or dead marine
mammal and the lead PSO determines that the injury or death is not
associated with or related to the activities authorized in the IHA
(e.g., previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), ADOT&PF will report the incident
to the Chief of the Permits and Conservation Division, Office of
Protected Resources, NMFS, and the NMFS Alaska Stranding Hotline and/or
by email to the Alaska Regional Stranding Coordinator, within 24 hours
of the discovery. ADOT&PF will provide photographs, video footage (if
available), or other documentation of the stranded animal sighting to
NMFS and the Marine Mammal Stranding Network.
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 7, 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 removal activities associated with the 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 A harassment and Level B harassment from underwater
sounds generated from pile driving and removal. Potential takes could
occur if individuals of these species are present in zones ensonified
above the thresholds for Level A or Level B harassment identified above
when these activities are underway.
Take by Level A and Level B harassment will be due to potential
behavioral disturbance, TTS, and PTS. No serious injury or mortality is
anticipated or authorized given the nature of the activity and measures
designed to minimize the possibility of injury to marine mammals. Take
by Level A harassment is only anticipated for harbor porpoise and
harbor seal. The potential for harassment is minimized through the
construction method and the implementation of the mitigation measures
(see Mitigation section).
Based on reports in the literature as well as monitoring from other
similar activities, behavioral disturbance (i.e., Level B harassment)
will likely be limited to reactions such as increased swimming speeds,
increased surfacing time, or decreased foraging (if such activity were
occurring) (e.g., Thorson and Reyff, 2006; HDR, Inc. 2012; Lerma, 2014;
ABR, 2016). Most likely for pile driving, individuals will simply move
away from the sound source and be temporarily displaced from the areas
of pile driving, although even this reaction has been observed
primarily in association with impact pile driving. The pile driving
activities analyzed here are similar to, or less impactful than,
numerous other construction activities conducted in southeast Alaska,
which have taken place with no observed severe responses of any
individuals or
[[Page 2597]]
known long-term adverse consequences. Level B harassment will be
reduced to the level of least practicable adverse impact through use of
mitigation measures described herein and, if sound produced by project
activities is sufficiently disturbing, animals are likely to simply
avoid the area while the activity is occurring. While vibratory driving
associated with the project may produce sound at distances of many
kilometers from the project site, thus overlapping with some likely
less-disturbed habitat, the project site itself is located in a busy
harbor and the majority of sound fields produced by the specified
activities are close to the harbor. Animals disturbed by project sound
would be expected to avoid the area and use nearby higher-quality
habitats.
In addition to the expected effects resulting from authorized Level
B harassment, we anticipate that harbor porpoises and harbor seals may
sustain some limited Level A harassment in the form of auditory injury.
However, animals in these locations that experience PTS will likely
only receive slight PTS, i.e., minor degradation of hearing
capabilities within regions of hearing that align most completely with
the energy produced by pile driving, not severe hearing impairment or
impairment in the regions of greatest hearing sensitivity. If hearing
impairment occurs, it is most likely that the affected animal will lose
a few decibels in its hearing sensitivity, which in most cases is not
likely to meaningfully affect its ability to forage and communicate
with conspecifics. As described above, we expect that marine mammals
will be likely to move away from a sound source that represents an
aversive stimulus, especially at levels that would be expected to
result in PTS, given sufficient notice through use of soft start.
The project also is not expected to have significant adverse
effects on affected marine mammals' habitat. The project activities
will not modify existing marine mammal habitat for a significant amount
of time. The activities may cause some fish or invertebrates to leave
the area of disturbance, thus temporarily impacting marine mammals'
foraging opportunities in a limited portion of the foraging range; but,
because of the short duration of the activities, the relatively small
area of the habitat that may be affected, and the availability of
nearby habitat of similar or higher value, the impacts to marine mammal
habitat are not expected to cause significant or long-term negative
consequences.
Nearly all inland waters of southeast Alaska, including Auke Bay,
are considered Biological Important Areas (BIA) for feeding at some
time of the year (Wild et al. 2023), and most are considered ephemeral,
as humpback whale distribution in southeast Alaska varies by season and
waterway (Dahlheim et al., 2009). The BIA that overlaps closest to the
project are active from April through October while the project is
scheduled to occur between October and March, so overlap with during
one month of the active BIA is expected. Additionally, pile driving
associated with the project is expected to take only 61 days, further
reducing the temporal overlap with the BIA. Therefore, the project is
not expected to have significant adverse effects on the foraging of
Alaska humpback whales. No areas of specific biological importance
(e.g., ESA critical habitat, other BIAs, or other areas) for any other
species are known to co-occur with the project area.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect any of the species or stocks
through effects on annual rates of recruitment or survival:
<bullet> No serious injury or mortality is anticipated or
authorized;
<bullet> Any Level A harassment exposures (i.e., to harbor
porpoises and harbor seals, only) are anticipated to result in slight
PTS (i.e., of a few decibels), within the lower frequencies associated
with pile driving;
<bullet> The anticipated incidents of Level B harassment will
consist of, at worst, temporary modifications in behavior that will not
result in fitness impacts to individuals;
<bullet> The area impacted by the specified activity is very small
relative to the overall habitat ranges of all species, does not include
ESA-designated critical habitat; and
<bullet> The mitigation measures are expected to reduce the effects
of the specified activity to the level of least practicable adverse
impact.
In combination, we believe that these factors, as well as the
available body of evidence from other similar activities, demonstrate
that the potential effects of the specified activities will have only
minor, short-term effects on individuals. The specified activities are
not expected to affect the reproduction or survival of any individual
marine mammals and, therefore, will not result in impacts on rates of
recruitment or survival for any species or stock.
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 monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the
activity will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
Table 7 demonstrates the number of animals that could be exposed to
received noise levels that could cause Level A and Level B harassment
for the work in Auke Bay. Our analysis shows that less than 28.5
percent of each affected stock could be taken by harassment. The
numbers of animals to be taken for these stocks will be considered
small relative to the relevant stock's abundances, even if each
estimated taking occurred to a new individual--an extremely unlikely
scenario.
Based on the analysis contained herein of the activity (including
the mitigation and monitoring measures) and the anticipated take of
marine mammals, NMFS finds that small numbers of marine mammals will be
taken relative to the population size of the affected species or
stocks.
Unmitigable Adverse Impact Analysis and Determination
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
[[Page 2598]]
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.
The project is not known to occur in an area important for
subsistence hunting. It is a developed area with regular marine vessel
traffic. However, ADOT&PF plans to provide advanced public notice of
construction activities to reduce construction impacts on local
residents, ferry travelers, adjacent businesses, and other users of the
Auke Bay ferry terminal and nearby areas. This will include
notification to local Alaska Native tribes that may have members who
hunt marine mammals for subsistence. Of the marine mammals considered
in this IHA application, only harbor seals are known to be used for
subsistence in the project area. If any tribes express concerns
regarding project impacts to subsistence hunting of marine mammals,
further communication between will take place, including provision of
any project information, and clarification of any mitigation and
minimization measures that may reduce potential impacts to marine
mammals.
Based on the description of the specified activity, the measures
described to minimize adverse effects on the availability of marine
mammals for subsistence purposes, and the mitigation and monitoring
measures, NMFS has determined that there will not be an unmitigable
adverse impact on subsistence uses from ADOT&PF's activities.
Endangered Species Act
There are two marine mammal species (western DPS Steller sea lion
and Mexico DPS humpback whale) with confirmed occurrence in the project
area that is listed as endangered and threatened respectively under the
ESA. The NMFS Alaska Regional Office Protected Resources Division
issued a Biological Opinion on December 22, 2023 under section 7 of the
ESA, on the issuance of an IHA to ADOT&PF under section 101(a)(5)(D) of
the MMPA by the NMFS Permits and Conservation Division. The Biological
Opinion concluded that this action is not likely to jeopardize the
continued existence of western DPS Steller sea lions or Mexico DPS
humpback whale, and is not likely to destroy or adversely modify
western DPS Steller sea lion or Mexico DPS humpback whale critical
habitats.
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 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 will 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 ADOT&PF for the potential harassment of
small numbers of 11 marine mammal species incidental to the
construction project in Auke Bay, Alaska, that includes the previously
explained mitigation, monitoring and reporting requirements. The issued
IHA can be found at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-alaska-department-transportation-pile-driving-and-removal">https://www.fisheries.noaa.gov/action/incidental-take-authorization-alaska-department-transportation-pile-driving-and-removal</a>.
Dated: January 9, 2024.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2024-00622 Filed 1-12-24; 8:45 am]
BILLING CODE 3510-22-P
</pre></body>
</html>Indexed from Federal Register on January 16, 2024.
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