[Federal Register Volume 88, Number 209 (Tuesday, October 31, 2023)]
[Notices]
[Pages 74440-74451]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-23948]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XD459]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Pier Maintenance and Bank 
Stabilization at U.S. Coast Guard Air Station Port Angeles, Port 
Angeles, Washington

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 authorization to the U.S. Coast Guard (Coast 
Guard or USCG) to harass marine mammals incidental to construction 
activities associated with pier maintenance and bank stabilization at 
USCG Air Station Port Angeles, Port Angeles, Washington.

DATES: This authorization is effective from July 16, 2024 through July 
15, 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: https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-coast-guard-air-station-port-angeles-pier-maintenance-and. In case of problems accessing these documents, 
please call the contact listed below.

FOR FURTHER INFORMATION CONTACT: Cara Hotchkin, OPR, NMFS, (301) 427-
8401.

SUPPLEMENTARY INFORMATION:

Background

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are proposed or, if the taking is limited to harassment, a notice of a 
proposed incidental harassment authorization (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

[[Page 74441]]

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 August 9, 2022, NMFS received a request from Coast Guard for an 
IHA to take marine mammals incidental to construction during pier 
maintenance activities at USCG Air Station Port Angeles in Port 
Angeles, Washington. Following NMFS' review of the application, Coast 
Guard submitted revised versions on May 11, 2023 and July 14, 2023. The 
application was deemed adequate and complete on July 18, 2023. The 
notice of proposed IHA was published in the Federal Register on 
September 7, 2023 (88 FR 61549). Coast Guard's request is for take of 
five species of marine mammals by Level B harassment only. Neither 
Coast Guard nor NMFS expect serious injury or mortality to result from 
this activity and, therefore, an IHA is appropriate.

Description of Activity

    Coast Guard plans to conduct pier maintenance and bank 
stabilization on a portion of the shoreline at USCG Air Station Port 
Angeles in Port Angeles, Washington. In-water work is expected to take 
approximately 15 days and will occur during daylight hours during the 
lowest possible tide conditions. USCG Air Station Port Angeles is 
located on the south-facing side of Ediz Hook, a peninsula that extends 
into the Strait of Juan de Fuca, encompassing approximately 8.73 square 
kilometers (km\2\) (3.37 square miles (mi\2\)), opening to the east. 
The U.S. Army Corps of Engineers has designated an in-water work window 
between July 16 and February 15 to protect anadromous fishes in the 
area. In-water work on this project may therefore occur between July 
16, 2024 and February 15, 2025. The planned work may result in the 
incidental take of marine mammals by Level B harassment due to exposure 
to underwater sound produced during impact and vibratory pile driving.
    The purpose of this project is to repair existing facilities and to 
protect vital mission support infrastructure from continued tidal 
action erosion and storm events. This project will repair up to 372 
feet (ft) (113.4 meters (m)) of eroded riprap shoreline, replace 37 
degraded timber piles with steel piles, repair up to 98 timber piles, 
permanently remove 11 abandoned timber piles and 3 steel camel barrier 
piles, and demolish 2 camels. Pile installation will be by vibratory 
and impact driving; pile removal methods would include direct pull and, 
if necessary, vibratory extraction. Impact and vibratory piling may 
occur on the same day, but the hammers would not operate 
simultaneously. Other components of this project include both in-water 
and upland activities, which are not expected to result in take of 
marine mammals. Pile repair (i.e., power washing, jacketing, and anti-
fouling coating), deck repair and replacement, utility installation, 
and shoreline stabilization (i.e., removal and replacement of riprap 
shoreline) are therefore not discussed further in this document.
    A detailed description of the planned construction project is 
provided in the Federal Register notice for the proposed IHA (88 FR 
61549, September 7, 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. Required mitigation, monitoring, 
and reporting measures are described in detail later in this document 
(please see Mitigation and Monitoring and Reporting).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to Coast Guard was 
published in the Federal Register on September 7, 2023 (88 FR 61549). 
That notice described, in detail, Coast Guard'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. During the 30-day 
public comment period, NMFS did not receive any public comments.

Changes From Proposed IHA to Final IHA

    Between the publication of the proposed IHA (88 FR 61549, September 
7, 2023) and this notice, Coast Guard requested that the effective 
dates of the authorization be shifted from November 15, 2023 through 
November 14, 2024 to July 16, 2024 through July 15, 2025 due to 
availability of funding and other logistical constraints. The analysis 
presented in the proposed IHA remains valid due to the consistent dates 
of the U.S. Army Corps of Engineers in-water work window (July 16 
through February 15 annually). The change to the effective dates of the 
authorization is reflected in the DATES section, above.

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

[[Page 74442]]

www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments.

                                            Table 1--Species Likely Impacted by the Specified Activities \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (y/n)      Nmin, most recent       PBR     Annual M/
                                                                                                \2\          abundance survey) \3\               SI \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Balaenopteridae (rorquals)
    Humpback whale..................  Megaptera novaeangliae.  Hawai[revaps]i.........  -, -, N             11,278 (0.56, 7,265,          127      27.09
                                                                                                             2020).
                                                               Mainland Mexico--CA/OR/  T, D, Y             3,477 (0.101, 3,185,           43         22
                                                                WA.                                          2022).
                                                               Central America/         E, D, Y             1,496 (0.171, 1,284,          5.2       14.9
                                                                Southern Mexico--CA/OR/                      2022).
                                                                WA.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                  Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae
    Killer whale....................  Orcinus orca...........  Eastern North Pacific    E, D, Y             74 (N/A, 74, 2021)....       0.13      >=0.4
                                                                Southern Resident.
                                                               West Coast Transient...  -, -, N             349 (N/A, 349, 2018)..        3.5        0.4
Family Phocoenidae (porpoises)
    Harbor porpoise.................  Phocoena phocoena......  Washington Inland        -, -, N             11,233 (0.37, 8,308,           66      >=7.2
                                                                Waters.                                      2015).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                               Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
 sea lions)
    Steller sea lion................  Eumetopias jubatus.....  Eastern................  -, -, N             43,201 (N/A, 43,201,        2,592        112
                                                                                                             2017).
    California sea lion.............  Zalophus californianus.  U.S....................  -, -, N             257,606 (N/A, 233,515,     14,011       >321
                                                                                                             2014).
Family Phocidae (earless seals)
    Harbor seal.....................  Phoca vitulina.........  Washington Northern      -, -, N             UNK (UNK, UNK, 1999)..        UND        9.8
                                                                Inland Waters.
    Northern elephant seal..........  Mirounga angustirostris  CA Breeding............  -, -, N             187,386 (N/A, 85,369,       5,122       13.7
                                                                                                             2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
  (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
\2\ 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.
\3\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable.
\4\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A
  CV associated with estimated mortality due to commercial fisheries is presented in some cases.

    A detailed description of the of the species likely to be affected 
by the USCG Pier Maintenance and Bank Stabilization project, including 
brief introductions to the species and relevant stocks as well as 
available information regarding population trends and threats, and 
information regarding local occurrence, were provided in the Federal 
Register notice for the proposed IHA (88 FR 61549, September 7, 2023); 
since that time, we are not aware of any changes in the status of these 
species and stocks; therefore, detailed descriptions are not provided 
here. Please refer to that Federal Register notice for these 
descriptions. Please also refer to NMFS' website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Not all marine mammal species have equal 
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and 
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al. 
(2007, 2019) recommended that marine mammals be divided into hearing 
groups based on directly measured (behavioral or auditory evoked 
potential 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.

[[Page 74443]]



                  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 et al., 
2013). This division between phocid and otariid pinnipeds is now 
reflected in the updated hearing groups proposed in Southall et al. 
(2019).
    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 Coast Guard's pile driving 
activities have the potential to result in behavioral harassment of 
marine mammals in the vicinity of the project area. The notice of the 
proposed IHA (88 FR 61549, September 7, 2023) included a discussion of 
the effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from Coast Guard's pile driving activities 
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 the proposed IHA (88 FR 
61549, September 7, 2023).

Estimated Take of Marine Mammals

    This section provides an estimate of the number of incidental takes 
authorized through the IHA, which informed both NMFS' consideration of 
``small numbers,'' and the negligible impact determinations.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as any act of 
pursuit, torment, or annoyance, which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes are by Level B harassment only, in the form of 
disruption of behavioral patterns and/or TTS for individual marine 
mammals resulting from exposure to noise from impact and vibratory pile 
driving. Based on the nature of the activity and the anticipated 
effectiveness of the mitigation measures (i.e., shutdown zones 
implemented at no less than the distance to the Level A isopleths) 
discussed in detail below in the Mitigation section, Level A harassment 
is neither anticipated nor authorized.
    As described previously, no serious injury or mortality is 
anticipated or authorized for this activity. Below we describe how the 
take numbers are estimated.
    For acoustic impacts, generally speaking, we estimate take by 
considering: (1) acoustic thresholds above which NMFS believes the best 
available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) the number of days of activities. We note 
that while these factors can contribute to a basic calculation to 
provide an initial prediction of potential takes, additional 
information that can qualitatively inform take estimates is also 
sometimes available (e.g., previous monitoring results or average group 
size). Below, we describe the factors considered here in more detail 
and present the take estimates.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
would be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment--Though significantly driven by received level, 
the onset of behavioral disturbance from anthropogenic noise exposure 
is also informed to varying degrees by other factors related to the 
source or exposure context (e.g., frequency, predictability, duty 
cycle, duration of the exposure, signal-to-noise ratio, distance to the 
source), the environment (e.g., bathymetry, other noises in the area, 
predators in the area), and the receiving animals (hearing, motivation, 
experience, demography, life stage, depth) and can be difficult to 
predict (e.g., Southall et al., 2007, 2021, Ellison et al., 2012). 
Based on what the available science indicates and the practical need to 
use a threshold based on a metric that is both predictable and 
measurable for most activities, NMFS typically uses a generalized 
acoustic threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced 
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile 
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g., 
scientific sonar) sources. Generally speaking, Level B harassment take 
estimates based on these behavioral harassment thresholds are expected 
to include any likely takes by TTS as, in most cases, the likelihood of 
TTS occurs at

[[Page 74444]]

distances from the source less than those at which behavioral 
harassment is likely. TTS of a sufficient degree can manifest as 
behavioral harassment, as reduced hearing sensitivity and the potential 
reduced opportunities to detect important signals (conspecific 
communication, predators, prey) may result in changes in behavior 
patterns that would not otherwise occur.
    Coast Guard's planned activity includes the use of continuous 
(e.g., vibratory pile installation and extraction) and impulsive (e.g, 
impact pile installation) 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). Coast 
Guard's planned construction activity includes the use of non-impulsive 
(e.g., vibratory pile installation and extraction) and impulsive (e.g, 
impact pile installation) sources.
    These thresholds are provided in table 3, 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: 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

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

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that are used in estimating the area ensonified above the 
acoustic thresholds, including source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the project. Marine 
mammals are expected to be affected via sound generated by the primary 
components of the project (i.e., impact pile driving and vibratory pile 
installation and removal). Calculation of the area ensonified by the 
planned action is dependent on source levels of the planned activities 
and the estimated transmission loss coefficients for the planned 
activities at the site. These factors are addressed below.
    Sound Source Levels of Activities--The intensity of pile driving 
sounds is greatly influenced by factors such as the type of piles 
(material and diameter), hammer type, and the physical environment 
(e.g., sediment type) 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, Coast Guard used acoustic monitoring data from sound source 
verification studies to develop proxy source levels for the various 
pile types, sizes and methods (table 4).

                                                                      Table 4--Pile Installation and Extraction Parameters
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                    Proxy levels (@10m)
                                                                                                        Strikes per  ------------------------------------------------
                Pile type                           Method             Total number   Number per day   pile or hours                                      dB re 1              Reference
                                                                                                          per day     dB re 1 [mu]Pa  dB re 1 [mu]Pa    [mu]Pa\2\s
                                                                                                                           peak             RMS            SELss
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
12-in steel.............................  Impact....................              37               5     100 strikes             192             177             166  CALTRANS 2020.
12-in steel.............................  Vibratory installation....              37              10           5 hrs  ..............             155  ..............  Greenbusch 2018.
18-in steel.............................  Vibratory installation....               3               2            1 hr  ..............             158  ..............  CALTRANS 2020.
12-14-in timber.........................  Vibratory extraction......              48              16           8 hrs  ..............             160  ..............  Greenbusch 2018.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

    Transmission Loss--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

[[Page 74445]]

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 bathymetry and presence or absence of 
reflective or absorptive 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 where water increases with depth as the 
receiver moves away from the shoreline, resulting in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions.
    Site-specific transmission loss measurements are not available for 
Port Angeles Harbor. NMFS has therefore used the practical spreading 
loss model for both vibratory and impact pile driving in this analysis.
    Estimated Harassment Isopleths--All Level B harassment isopleths 
are reported in table 5. Level B harassment isopleths from the project 
will be limited by the coastline along and across from the project 
site. The maximum attainable isopleth distance is 4,642 m during 
vibratory extraction of timber piles (see Figure 1 in the IHA 
application for further detail).
    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, including pile driving, the optional User 
Spreadsheet tool predicts the distance at which, if a marine mammal 
remained at that distance for the duration of the activity, it would be 
expected to incur PTS. Inputs used in the User Spreadsheet (e.g., 
number of piles per day, duration and/or strikes per pile, source 
levels) are presented in table 4. The resulting isopleths and 
ensonified areas are reported in table 5 and table 6, respectively.

                                                        Table 5--Estimated Isopleths by Activity
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                       Underwater harassment isopleths [m]                          Airborne Level B
                                                 ------------------------------------------------------------------------------ harassment isopleths [m]
           Activity                  Method                                   Level A                                          -------------------------
                                                 -----------------------------------------------------------------   Level B       Harbor       Other
                                                       LF           MF           HF           PW           OW                      seals      pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-in steel..................  Impact...........         46.0          1.6         55.0         25.0          2.0        136.0          150           47
12-in steel..................  Vibratory                  8.0          0.7         11.8          4.8          0.3        2,154           19            6
                                installation.
18-in steel..................  Vibratory                  4.3          0.4          6.4          2.6          0.2        3,415
                                installation.
12-14-in timber..............  Vibratory                 23.4          2.1         34.6         14.2          1.0        4,642
                                extraction.
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                                         Table 6--Areas Ensonified (Underwater)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Level A harassment [km\2\]                                Level B
             Activity                      Method        --------------------------------------------------------------------------------   harassment
                                                                LF              MF              HF              PW              OW            [km\2\]
--------------------------------------------------------------------------------------------------------------------------------------------------------
12-in steel......................  Impact...............            0.02           <0.01            0.02            0.01           <0.01            0.07
12-in steel......................  Vibratory                       <0.01           <0.01           <0.01           <0.01           <0.01            7.74
                                    installation.
18-in steel......................  Vibratory                       <0.01           <0.01           <0.01           <0.01           <0.01           14.52
                                    installation.
12-14-in timber..................  Vibratory extraction.            0.01           <0.01            0.02           <0.01           <0.01           17.59
--------------------------------------------------------------------------------------------------------------------------------------------------------

Marine Mammal Occurrence

    In this section we provide information about the occurrence of 
marine mammals, including density or other relevant information which 
will inform the take calculations.
    For marine mammal density information in the Port Angeles area we 
used data from the Pacific Navy Marine Species Density Database (U.S. 
Navy, 2019) to estimate take for marine mammals. The Marine Species 
Density Database incorporates analyzed literature and research for 
marine mammal density estimates per season for the Gulf of Alaska and 
the West Coast of the United States. Density estimates specific to the 
Strait of Juan de Fuca are not available for any of the species 
addressed here, and therefore takes were estimated based on the nearest 
available and most appropriate density estimates, plus site-specific 
knowledge and professional judgement. Table 7 density estimates are 
calculated based on the in-water work window (July-February) and based 
on the highest seasonal density estimates for the relevant area.

        Table 7--Seasonal Density of Species in the Project Area
------------------------------------------------------------------------
                  Species                     Densities (animals/km\2\)
------------------------------------------------------------------------
Humpback whale............................  0.0027 (summer/fall).
Killer whale--Southern Resident...........  0.0012 (summer).
Killer whale--Transient...................  0.0208 (fall).
Harbor porpoise...........................  2.16 (annual).
Harbor seal...............................  0.76 (summer/fall).
Northern elephant seal....................  0.0029 (fall).
Steller sea lion..........................  0.0027 (fall/winter).

[[Page 74446]]

 
California sea lion.......................  0.300 (September).
------------------------------------------------------------------------

Take Estimation

    Here we describe how the information provided above is synthesized 
to produce a quantitative estimate of the take that is reasonably 
likely to occur and authorized under the IHA.
    Using the overall area of disturbance generated by pile removal and 
installation given calculated distances to attenuation below 
disturbance (Level B harassment) thresholds, incidental take for each 
activity is estimated by the following equation:

Incidental take estimate = species density * ensonified area* days of 
pile-related activity

    This equation is a reasonable extrapolation for take estimates, 
which relies on the likelihood that a species is present within the 
ensonified area on a day where the planned activity is occurring. Take 
estimates were calculated with the conservative assumption that each 
activity (i.e., vibratory extraction of steel piles, vibratory 
extraction of timber piles, vibratory installation, and impact 
installation) will occur on separate days, using a maximum of 23 days 
of in-water work. However, Coast Guard will perform some activities on 
the same day, resulting in reduced numbers of overall take during the 
planned 15 days of pile driving.
    No take by Level A harassment is authorized for any species of 
marine mammal due to the small zones, in conjunction with Coast Guard's 
required shutdown mitigation measure. Shutdown zones will be enforced 
at the extent of the estimated Level A harassment isopleth for all 
species groups except for large whales (i.e., baleen whales, including 
humpbacks, and killer whales). Coast Guard plans to shut down for 
killer whales upon observation regardless of location in order to 
prevent potential take of members of the Southern Resident stock, and 
shutdown zones for other large whale species will be enforced at the 
extent of the Level B harassment isopleths. Given the remote likelihood 
of large whale species entering Port Angeles Harbor during the 15 days 
of pile driving work (see calculated take estimates for humpback and 
killer whales in table 8) and the locations of Protected Species 
Observers (PSOs) described in the Monitoring and Reporting section, 
NMFS agrees that monitoring and shutdown measures are likely to be 
successful at avoiding take of these species. Therefore, no take of 
large whale species (including but not limited to humpback and killer 
whales) has been requested and none is authorized.
    Based on sightings reported during the 2016-2017 Navy TPS Port 
Angeles project (Northwest Environmental Consulting, LLC 2018), Coast 
Guard anticipates the number of harbor seals present in the project 
area during the planned in-water activities may exceed calculated 
exposure estimates. During the 2016-2017 Navy TPS Port Angeles project, 
275 harbor seals were observed in the estimated Level B harassment zone 
over approximately 45 days during which pile driving occurred 
(Northwest Environmental Consulting, LLC., 2018). Coast Guard project 
will have only 15 days of in-water pile driving. Therefore, Coast Guard 
has requested, and NMFS has authorized, 210 incidents of Level B 
harassment for harbor seals, approximately half the difference in 
sightings between the 2016-2017 Navy TPS Port Angeles project and the 
calculated exposure estimate for this project.

                                        Table 8--Calculated and Authorized Amount of Taking and Percent of Stocks
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Take by Level A harassment      Take by Level B harassment
               Species                          Stock          ----------------------------------------------------------------  Total take   Percent of
                                                                  Calculated      Authorized      Calculated      Authorized                    stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale.......................  Hawai[revaps]i.........               0               0            0.51               0            0            0
                                       Mainland Mexico--CA/OR/
                                        WA.
                                       Central America/
                                        Southern Mexico--CA/OR/
                                        WA.
Killer whale.........................  Eastern North Pacific                 0               0            0.23               0            0            0
                                        Southern Resident.
                                       West Coast Transient...               0               0            3.94               0            0            0
Harbor porpoise......................  Washington Inland                  0.73               0           408.9             409          409         4.92
                                        Waters.
Harbor seal..........................  Washington Northern                0.13               0           143.9             210          210       \1\ NA
                                        Inland Waters.
Northern Elephant Seal...............  CA Breeding............               0               0            0.55               1            1        <0.01
Steller Sea Lion.....................  Eastern................               0               0            0.51               1            1        <0.01
California Sea lion..................  U.S....................             0.1               0            56.8              57           57         0.02
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Stock size for the Washington Northern Inland Waters stock of harbor seals is not available from the most recent SARs due to a lack of recent data.

Mitigation

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

[[Page 74447]]

(probability implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost and impact on 
operations.
    Shutdown Zones--The purpose of a shutdown zone is generally to 
define an area within which shutdown of the activity would occur upon 
sighting of a marine mammal (or in anticipation of an animal entering 
the defined area). Construction supervisors and crews, Protected 
Species Observers (PSO), and relevant Coast Guard staff must avoid 
direct physical interaction with marine mammals during construction 
activities, which could include (but are not limited to) the following: 
(1) barge movement to the pile location; (2) pile positioning on the 
substrate via a crane (i.e., stabbing the pile); and (3) pile removal 
from the water column/substrate via a crane (i.e., deadpull). If a 
marine mammal comes within 10 meters of such activity, operations must 
cease and vessels must reduce speed to the minimum level required to 
maintain steerage and safe working conditions, as necessary to avoid 
direct physical interaction.
    Further, Coast Guard must implement activity-specific shutdown 
zones as described in table 9. The shutdown zone for humpback whales or 
other non-authorized marine mammal species (except killer whales) will 
be the predicted Level B harassment isopleth. For these species, 
project activity may resume after the animal has not been observed for 
15 minutes, or has been observed leaving the shutdown zone (i.e. the 
Level B harassment zone). As proposed by Coast Guard, killer whales 
will require a shutdown upon observation no matter location in order to 
prevent take of members of the Southern Resident stock. If killer 
whales are sighted, the project activity would resume only after the 
killer whale is not observed for 15 minutes.

                                                            Table 9--Required Shutdown Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                Shutdown zone (m)                             Monitoring
                                                                    ------------------------------------------------------------------------ zone  (m)--
               Pile type                    Pile  driving method                                                                                 all
                                                                           Killer whales           LF       MF       HF       PW       OW      species
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steel..................................  Vibratory.................  Any sighting at any          3,415                  12                        3,415
                                                                      distance.
                                         Impact....................                                 136                  55                          136
Timber.................................  Vibratory.................                               4,642                  35                        4,642
--------------------------------------------------------------------------------------------------------------------------------------------------------

    Protected Species Observers--The placement of PSOs during all 
construction activities (described in the Monitoring and Reporting 
section) will ensure that the entire shutdown zone is visible. Coast 
Guard will employ three PSOs for vibratory installation and extraction 
of steel and timber piles. Two PSOs will be land-based, while one will 
be positioned on a vessel to ensure full monitoring coverage to the 
estimated Level B harassment isopleth. For impact pile driving 
activities, Coast Guard will employ one PSO.
    Pre and Post-Activity Monitoring--Monitoring must take place from 
30 minutes prior to initiation of pile driving activity (i.e., pre-
start clearance monitoring) through 30 minutes post-completion of pile 
driving activity. Pre-start clearance monitoring must be conducted 
during periods of visibility sufficient for the lead PSO to determine 
that the shutdown zones indicated in table 9 are clear of marine 
mammals. Pile driving may commence following 30 minutes of observation 
when the determination is made that the shutdown zones are clear of 
marine mammals. If a marine mammal is observed entering or within the 
shutdown zones, pile driving activity must be delayed or halted. If 
pile driving is delayed or halted due to the presence of a marine 
mammal, the activity may not commence or resume until either the animal 
has voluntarily exited and been visually confirmed beyond the shutdown 
zone or 15 minutes have passed without re-detection of the animal. If a 
marine mammal for which take by Level B harassment is authorized is 
present in the Level B harassment zone, activities will begin and Level 
B harassment take will be recorded.
    Monitoring for Level B Harassment--PSOs will monitor the shutdown 
zones and beyond to the extent that PSOs can see. For this activity, 
the monitoring zone is defined as the largest predicted Level B 
harassment isopleth for a given activity (table 9). Monitoring beyond 
the shutdown zones enables observers to be aware of and communicate the 
presence of marine mammals in the project areas outside the shutdown 
zones and thus prepare for a potential cessation of activity should the 
animal enter the shutdown zone. If weather or sea conditions restrict 
the observer's ability to observe the monitoring zone, pile driving 
activities must cease until conditions are favorable for observations 
to resume.
    Soft Start--Soft-start procedures are used to provide additional 
protection to marine mammals by providing warning and/or giving marine 
mammals a chance to leave the area prior to the hammer operating at 
full capacity. For impact pile driving, soft start requires contractors 
to provide an initial set of three strikes at reduced energy, followed 
by a 30-second waiting period, then two subsequent reduced-energy 
strike sets. A soft start must be implemented at the start of each 
day's impact pile driving and at any time following cessation of impact 
pile driving for a period of 30 minutes or longer.
    If unsafe working conditions during ramp ups are reported (e.g., 
crane failure from excess wear due to the ramp up procedure) by the 
contractor and verified by an independent safety inspection, Coast 
Guard may elect to discontinue impact driver ramp ups. Coast Guard will 
inform NMFS if the ramp up procedure is discontinued. If use of a 
variable moment driver is infeasible and the model of impact driver was 
not specifically designed for ramp up procedures, then Coast Guard will 
not employ impact ramp up procedures due to personnel safety concerns.
    In-water Work Window--To reduce impacts to marine fishes, Coast 
Guard will follow the in-water work window designated for the Strait of 
Juan de Fuca and associated bays and inlets by the U.S. Army Corps of 
Engineers. The work window extends from July 16 to February 15; no in-
water work will be conducted outside of that date range unless a 
modification is negotiated with the relevant regulatory agencies, 
including the U.S. Army Corps of Engineers.
    NMFS and Coast Guard considered the use of bubble curtains as a 
mitigation measure during this project. However, based on the limited 
amount of impact driving expected, the relatively small estimated Level 
A harassment isopleths, and the potential

[[Page 74448]]

for increased turbidity during bubble curtain use, NMFS has determined 
that use of a bubble curtain would not further reduce take of marine 
mammals during this project and they are not included in the required 
mitigation methods.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has determined that the 
described mitigation measures provide the means of effecting the least 
practicable impact on the affected species or stocks and their habitat, 
paying particular attention to rookeries, mating grounds, and areas of 
similar significance.

Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth requirements pertaining to the 
monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present while 
conducting the activities. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the activity; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    <bullet> Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
Marine Mammal Monitoring Plan, dated July 2023, available online at 
https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-coast-guard-air-station-port-angeles-pier-maintenance-and. Marine 
mammal monitoring during pile driving and removal must be conducted by 
NMFS-approved PSOs in a manner consistent with the following:
    <bullet> PSOs must be independent of the activity contractor (for 
example, employed by a subcontractor) and have no other assigned tasks 
during monitoring periods;
    <bullet> At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
    <bullet> Other PSOs may substitute other relevant experience, 
education (degree in biological science or related field) or training 
for experience performing the duties of a PSO during construction 
activities pursuant to a NMFS-issued incidental take authorization;
    <bullet> Where a team of three or more PSOs is required, a lead 
observer or monitoring coordinator must be designated. The lead 
observer must have prior experience performing the duties of a PSO 
during construction activity pursuant to a NMFS-issued incidental take 
authorization; and
    <bullet> PSOs must be approved by NMFS prior to beginning any 
activity subject to this IHA.
    PSOs should have the following additional qualifications:
    <bullet> Ability to conduct field observations and collect data 
according to assigned protocols;
    <bullet> Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    <bullet> Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    <bullet> Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
    <bullet> Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    A team of one to two land based PSOs will be deployed to observe 
the monitoring zones for vibratory and impact pile driving during this 
project. PSOs will be located at the best vantage points to see the 
entirety of the active zone. One PSO will have an unobstructed view of 
all water within the shutdown zones, and will be stationed at or near 
the project activity. While the exact monitoring stations have not yet 
been determined, Coast Guard provided potential locations in Figure 1 
of its Marine Mammal Monitoring and Mitigation Plan. Additionally, a 
PSO will be stationed for monitoring on an observation vessel in order 
to ensure the entire monitoring zone to the extent of the relevant 
predicted Level B harassment isopleth can be observed during vibratory 
pile installation and removal.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after all in water construction activities. In addition, PSOs 
will record all incidents of marine mammal occurrence, regardless of 
distance from activity, and will document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving equipment is no more than 30 minutes.

Reporting

    Coast Guard will submit a draft report to NMFS within 90 calendar 
days of the completion of monitoring or 60 calendar days prior to the 
requested issuance of any subsequent IHA for construction activity at 
the same location, whichever comes first. The marine mammal monitoring 
report will include an overall description of work completed, a 
narrative regarding marine mammal sightings, and associated PSO data 
sheets. Specifically, the report would include:
    <bullet> Dates and times (begin and end) of all marine mammal 
monitoring;
    <bullet> Construction activities occurring during each daily 
observation period, including: (1) The number and type of piles that 
were driven and the method (e.g., impact or vibratory); and (2) Total

[[Page 74449]]

duration of driving time for each pile (vibratory driving) and 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: (1) Name of PSO who sighted the animal(s) and PSO location 
and activity at time of sighting; (2) Time of sighting; (3) 
Identification of the animal(s) (e.g., genus/species, lowest possible 
taxonomic level, or unidentified), PSO confidence in identification, 
and the composition of the group if there is a mix of species; (4) 
Distance and location of each observed marine mammal relative to the 
pile being driven for each sighting; (5) Estimated number of animals 
(min/max/best estimate); (6) Estimated number of animals by cohort 
(adults, juveniles, neonates, group composition, etc.); (7) Animal's 
closest point of approach and estimated time spent within the 
harassment zone; (8) Description of any marine mammal behavioral 
observations (e.g., observed behaviors such as feeding or traveling), 
including an assessment of behavioral responses thought to have 
resulted from the activity (e.g., no response or changes in behavioral 
state such as ceasing feeding, changing direction, flushing, or 
breaching);
    <bullet> Number of marine mammals detected within the harassment 
zones, by species; and
    <bullet> Detailed information about implementation of any 
mitigation (e.g., shutdowns and delays), a description of specific 
actions that ensued, and resulting changes in behavior of the 
animal(s), if any.
    A final report must be prepared and submitted within 30 calendar 
days following receipt of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 calendar days of receipt of 
the draft report, the report shall be considered final.
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, Coast Guard must report the 
incident to the OPR, NMFS (<a href="/cdn-cgi/l/email-protection#3060621e7964601e7d5f5e59445f42595e576255405f424443705e5f51511e575f46"><span class="__cf_email__" data-cfemail="0555572b4c51552b486a6b6c716a776c6b625760756a777176456b6a64642b626a73">[email protected]</span></a> and 
<a href="/cdn-cgi/l/email-protection#caa3bebae4a2a5bea9a2a1a3a48aa4a5ababe4ada5bc"><span class="__cf_email__" data-cfemail="f49d8084da9c9b80979c9f9d9ab49a9b9595da939b82">[email protected]</span></a>) and to the West Coast regional stranding network 
(866-767-6114) as soon as feasible. If the death or injury was clearly 
caused by the specified activity, Coast Guard must immediately cease 
the activities until NMFS OPR is able to review the circumstances of 
the incident and determine what, if any, additional measures are 
appropriate to ensure compliance with the terms of this IHA. Coast 
Guard must not resume their activities until notified by NMFS. The 
report must include the following information:
    [ssquf] Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    [ssquf] Species identification (if known) or description of the 
animal(s) involved;
    [ssquf] Condition of the animal(s) (including carcass condition if 
the animal is dead);
    [ssquf] Observed behaviors of the animal(s), if alive;
    [ssquf] If available, photographs or video footage of the 
animal(s); and
    [ssquf] General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any impacts or responses (e.g., intensity, duration), 
the context of any impacts or responses (e.g., critical reproductive 
time or location, foraging impacts affecting energetics), as well as 
effects on habitat, and the likely effectiveness of the mitigation. We 
also assess the number, intensity, and context of estimated takes by 
evaluating this information relative to population status. Consistent 
with the 1989 preamble for NMFS' implementing regulations (54 FR 40338; 
September 29, 1989), the impacts from other past and ongoing 
anthropogenic activities are incorporated into this analysis via their 
impacts on the baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    To avoid repetition, the majority of our analysis applies to all 
the species listed in table 8, 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 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 B harassment, identified above, when these activities are 
underway.
    The takes by Level B harassment would be due to potential 
behavioral disturbance. No mortality or serious injury is anticipated 
given the nature of the activity, and no Level A harassment is 
anticipated due to Coast Guard's construction method and the required 
mitigation measures (see Mitigation section).
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, would 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, individuals 
would simply move away from the sound source and be temporarily 
displaced from the areas of pile driving and removal, although even 
this reaction has been observed primarily only in association with 
impact pile driving, which Coast Guard anticipates using for only 10 
percent of pile driving. If sound produced by project activities is 
sufficiently disturbing, animals are likely to simply avoid the area 
while the activity is occurring, particularly as the project is 
expected to occur over just 15 in-water pile driving days.
    The project is also not expected to have significant adverse 
effects on affected marine mammals' habitats. The project activities 
would not modify

[[Page 74450]]

existing marine mammal habitat for a significant amount of time. The 
activities may cause some fish to leave the area of disturbance, thus 
temporarily impacting marine mammals' foraging opportunities in a 
limited portion of the foraging range. Given the short duration of the 
activities and the relatively small area of the habitat that may be 
affected, the impacts to marine mammal habitat, including fish, are not 
expected to cause significant or long-term negative consequences.
    There are two known harbor seal haulouts close to the project site. 
The first haulout site is directly across Port Angeles Harbor from the 
USCG Air Station, approximately 2.4 km away. Seals swimming to and from 
this haulout have the potential to experience Level B harassment due to 
underwater sound exposure during vibratory or impact pile driving 
activities. However, the project activities are not expected to occur 
during any particularly sensitive time (e.g., molting or pupping 
season), and the project duration is short, with approximately 15 days 
of in-water work. Given the availability of a second haulout close by 
(3.5 km (2.17 mi) from the project site on the opposite side of Ediz 
Hook) which is not expected to be exposed to noise from pile driving, 
and the short duration of the project, there are no anticipated 
significant or long-term negative consequences to harbor seals in 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> The anticipated incidents of Level B harassment would 
consist of, at worst, temporary modifications in behavior that would 
not result in fitness impacts to individuals;
    <bullet> Take estimates were calculated assuming that no activities 
would occur on the same day. However, in reality, vibratory and impact 
driving are likely to occur on the same day, reducing the overall 
impact to marine mammal species;
    <bullet> The area impacted by the specified activity is very small 
relative to the overall habitat ranges of all species;
    <bullet> While impacts will occur within areas that are important 
for feeding or resting for multiple stocks, because of the small 
footprint of the activity relative to the area of these important use 
areas, and the scope and nature of the anticipated impacts of pile 
driving exposure, we do not expect impacts to the reproduction or 
survival of any individuals.
    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 described monitoring and 
mitigation measures, NMFS finds that the total marine mammal take from 
the planned activity will have a negligible impact on all affected 
marine mammal species or stocks.

Small Numbers

    As noted previously, only take of small numbers of marine mammals 
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    The number of instances of take for each species or stock 
authorized to be taken as a result of this project is included in table 
8. Our analysis shows that less than one-third of the best available 
population abundance estimate of each stock could be taken by 
harassment. The number of animals authorized to be taken for all stocks 
would be considered small relative to the relevant stock's abundances 
even if each estimated taking occurred to a new individual, which is an 
unlikely scenario.
    A lack of an accepted stock abundance value for the Washington 
Northern Inland Waters stock of harbor seal did not allow for the 
calculation of an expected percentage of the population that would be 
affected. The most relevant estimate of partial stock abundance is 
7,513 seals (CV = 11.5%) (Jefferson et al. 2021). Given 210 authorized 
takes by Level B harassment for the stock, comparison to the best 
estimate of stock abundance shows, at most, 2.8 percent of the stock 
would be expected to be impacted.
    Based on the analysis contained herein of the planned activity 
(including the required mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS finds that small numbers of 
marine mammals would be taken relative to the population size of the 
affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
determined that the total taking of affected species or stocks would 
not have an unmitigable adverse impact on the availability of such 
species or stocks for taking for subsistence purposes.

Endangered Species Act

    Section 7(a)(2) of the ESA of 1973 (16 U.S.C. 1531 et seq.) 
requires that each Federal agency insure that any action it authorizes, 
funds, or carries out is not likely to jeopardize the continued 
existence of any endangered or threatened species or result in the 
destruction or adverse modification of designated critical habitat. To 
ensure ESA compliance for the issuance of IHAs, NMFS consults 
internally whenever we propose to authorize take for endangered or 
threatened species.
    No incidental take of ESA-listed species is authorized or expected 
to result from this activity. Therefore, NMFS has determined that 
formal consultation under section 7 of the ESA is not required for this 
action.

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our action (i.e., the issuance of an IHA) with respect 
to potential impacts on the human environment.
    This action is consistent with categories of activities identified 
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or 
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has determined 
that the issuance of the IHA qualifies to be categorically excluded 
from further NEPA review.

Authorization

    NMFS has issued an IHA to Coast Guard for the potential harassment 
of

[[Page 74451]]

small numbers of five marine mammal species incidental to the Pier 
Maintenance and Bank Stabilization project in Port Angeles, Washington, 
that includes the previously explained mitigation, monitoring and 
reporting requirements. The IHA can be found at: https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-coast-guard-air-station-port-angeles-pier-maintenance-and.

    Dated: October 25, 2023.
Catherin Marzin,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2023-23948 Filed 10-30-23; 8:45 am]
BILLING CODE 3510-22-P


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