Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Replacement of Pier 302 at Naval Base Point Loma, San Diego, California, 6703-6714 [2023-02107]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 88, Number 21 (Wednesday, February 1, 2023)]
[Notices]
[Pages 6703-6714]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-02107]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XC585]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Replacement of Pier 302 at Naval 
Base Point Loma, San Diego, California

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

ACTION: Notice; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that NMFS has issued an incidental harassment authorization (IHA) to 
the U.S. Navy to incidentally harass, by Level B harassment only, 
marine mammals during construction activities associated with a Pier 
302 Replacement project at Naval Base Point Loma, San Diego, 
California.

DATES: This authorization is effective from October 1, 2023 through 
September 30, 2024.

FOR FURTHER INFORMATION CONTACT: Jessica Taylor, Office of Protected 
Resources, NMFS, (301) 427-8401. 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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems 
accessing these documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

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

Summary of Request

    On July 27, 2022, NMFS received a request from the U.S. Navy for an 
IHA to take marine mammals incidental to construction activities 
associated with replacing Pier 302 at Naval Base Point Loma (NBPL), San 
Diego, CA. Following NMFS' review of the application, the U.S. Navy 
submitted a revised version on September 22, 2022. The application was 
deemed adequate and complete on October 27, 2022. The U.S. Navy's 
request is for take of six species of marine mammals by Level B 
harassment only. Neither the U.S. Navy nor NMFS expect serious injury 
or mortality to result from this activity, therefore, an IHA is 
appropriate. There were no changes from the proposed to the final IHA.
    NMFS has previously issued IHAs to the U.S. Navy for similar work 
over the past 9 years at NBPL in San Diego Bay (Bay), including IHAs 
issued effective from September 1, 2013, through August 31, 2014 (78 FR 
44539, July 24, 2013; Year 1 Project), October 8, 2014 through October 
7, 2015 (79 FR 65378, November 4, 2014; Year 2 Project), October 8, 
2015 through October 7, 2016 (80 FR 62032, October 15, 2015; Year 3 
Project), October 8, 2016 through October 7, 2017 (81 FR 66628,

[[Page 6704]]

September 28, 2016; Year 4 Project), October 8, 2017 through October 7, 
2018 (82 FR 45811, October 2, 2017; Year 5 Project), September 15, 2020 
through September 14, 2021 (85 FR 33129, June 1, 2020; Floating Dry 
Dock Project), October 1, 2021 through September 30, 2022 (86 FR 7993, 
February 3, 2021; Pier 6 Replacement Project), and January 15, 2022 
through January 14, 2023 (86 FR 48986, September 1, 2021; Fuel Pier 
Inboard Pile Removal Project). The U.S. Navy complied with all the 
requirements (e.g., mitigation, monitoring, and reporting) of the 
previous IHA and information regarding their monitoring results 
specific to NBPL may be found in the Estimated Take section.

Description of Activity

    The U.S. Navy plans to replace Pier 302 at the Naval Information 
Warfare Center (NIWC) Pacific Bayside Complex on NBPL. Pier 302 houses 
the U.S. Navy marine mammal pens and support vessels. As part of the 
project, the U.S. Navy will use vibratory extraction to remove the 
existing components of marine mammal pens, and impact and vibratory 
hammers to install new pens. The purpose of the project is to provide 
the U.S. Navy's marine mammal program with adequate facilities to house 
its marine mammals and provide a safe working environment for personnel 
to support the U.S. Navy's overall mission to maintain, train, and 
equip combat ready Naval forces.
    The Navy's activity includes impact and vibratory pile driving, 
which may result in the incidental take of marine mammals, by Level B 
harassment only. No Level A harassment is anticipated to occur, and 
none is authorized. Due to mitigation measures, only takes by Level B 
harassment are requested. NBPL is located along the mouth and northern 
edge of San Diego Bay, CA. The project covers an area of 9,061 feet 
(ft.)\2\ (842 meters (m)\2\). Construction activities will occur over 
32 days within a 1 year window from October 1, 2023 to September 30, 
2024. The Navy states that it will conduct work only in daylight hours. 
A detailed description of the planned construction project is provided 
in the Federal Register notice for the proposed IHA (87 FR 68442, 
November 15, 2022). 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. 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 the U.S. Navy was 
published in the Federal Register on November 15, 2022 (87 FR 68442). 
That notice described, in detail, the U.S. Navy's activities, the 
marine mammal species that may be affected by the activities, and the 
anticipated effects on marine mammals. During the 30-day public comment 
period, no public comments were received.

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history of the potentially affected species. NMFS 
fully considered all of this information, and we refer the reader to 
these descriptions, incorporated here by reference, 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 expected to occur, 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.
    There are six marine mammal species that are potentially expected 
to be present during all or a portion of the in-water work associated 
with this project in San Diego Bay, including the California sea lion 
(Zalophus californianus), the northern elephant seal (Mirounga 
angustirostris), the harbor seal (Phoca vitulina), the bottlenose 
dolphin (Tursiops truncatus), the Pacific white-sided dolphin 
(Lagenorhynchus obliquidens), and the common dolphin (Delphinus 
delphis). The Committee on Taxonomy (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/) 
recently determined both the long-beaked and short-beaked common 
dolphin belong in the same species and we adopt this taxonomy. However, 
the SARs still describe the two as separate stocks, and that stock 
information is presented in Table 1. 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 
some species, this geographic area may extend beyond U.S. waters. All 
stocks managed under the MMPA in this region are assessed in NMFS' U.S. 
Pacific 2021 SARs. All values presented in Table 2 are the most recent 
available at the time of publication and are available online at: 
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments).

                                     Table 1--Marine Mammal Species \4\ Likely Impacted by the Specified Activities
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                                                                                         ESA/ MMPA status;   Stock abundance (CV,
             Common name                  Scientific name               Stock             strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
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                              Order Artiodactyla--Infraorder Cetacea-- Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
    Bottlenose dolphin..............  Tursiops truncatus.....  California Coastal.....  -, -, N             453 (0.06, 346, 2011).        2.7      >=2.0
    Short-beaked common dolphin.....  Delphinus delphis        California/Oregon/       -, -, N             1,056,308 (0.21,             8889     >=30.5
                                       delphis.                 Washington.                                  888,971, 2018).

[[Page 6705]]

 
    Long-beaked common dolphin......  Delphinus delphis        California.............  -, -, N             83,379 (0.216, 69,636,        668     >=29.7
                                       capensis.                                                             2018).
    Pacific white-sided dolphin.....  Lagenorhynchus           California/Oregon/       -, -, N             34,999 (0.222, 29,090,        279          7
                                       obliquidens.             Washington.                                  2018).
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                                                               Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California sea lion.............  Zalophus californianus.  U.S....................  -, -, N             257,606 (N/A,233,515,       14011       >320
                                                                                                             2014).
Family Phocidae (earless seals):
    Harbor seal.....................  Phoca vitulina.........  California.............  -, -, N             30,968 (N/A, 27,348,         1641         43
                                                                                                             2012).
    Northern elephant seal..........  Mirounga angustirostris  California breeding....  -, -, N             187,386 (N/A, 85,369,        5122       13.7
                                                                                                             2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments/ assessments/. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\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.
\4\ 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)).

    As indicated above, all six species (with seven managed stocks) in 
Table 1 temporally and spatially co-occur with the activity to the 
degree that take is reasonably likely to occur. While gray whales, 
Risso's dolphins, and Steller sea lions have been sighted around 
California coastal waters in the past, these species' general spatial 
occurrence is such that take is not expected to occur as they typically 
occur more offshore. Therefore, the Navy did not request, and NMFS is 
not authorizing take of these species.
    A detailed description of the species likely to be affected by the 
Naval Base Point Loma Pier 302 Replacement 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 (87 FR 68442, November 15, 2022); 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 the 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.

                  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).

[[Page 6706]]

 
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

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

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the Navy'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 (87 FR 68442, November 15, 2022) included a discussion of 
the effects of anthropogenic noise on marine mammals and the potential 
effects of underwater noise from the Navy'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 (87 FR 
68442, November 15, 2022).

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which has 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 will be by Level B harassment only, in the form of 
disruption of behavioral patterns for individual marine mammals 
resulting from exposure to the acoustic sources. Based on the nature of 
the activity and the anticipated effectiveness of the mitigation 
measures (i.e., vibratory or impact pile driving and removal) 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 
authorized take numbers are estimated.
    For acoustic impacts, generally speaking, we estimate take by 
considering: (1) acoustic thresholds above which NMFS believes the best 
available science indicates marine mammals will be behaviorally 
harassed or incur some degree of permanent hearing impairment; (2) the 
area or volume of water that will be ensonified above these levels in a 
day; (3) the density or occurrence of marine mammals within these 
ensonified areas; and, (4) the number of days of activities. We note 
that while these factors can contribute to a basic calculation to 
provide an initial prediction of potential takes, additional 
information that can qualitatively inform take estimates is also 
sometimes available (e.g., previous monitoring results or average group 
size). Below, we describe the factors considered here in more detail 
and present the authorized take estimates.

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 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 threshold based on received level to estimate the onset of 
behavioral harassment. NMFS generally predicts that marine mammals are 
likely to be behaviorally harassed in a manner considered to be Level B 
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced 
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile-
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g., 
scientific sonar) sources. Generally speaking, Level B harassment take 
estimates based on these behavioral harassment thresholds are expected 
to include any likely takes by temporary threshold shift (TTS) as, in 
most cases, the likelihood of TTS occurs at distances from the source 
less than those at which behavioral harassment is likely. TTS of a 
sufficient degree can manifest as behavioral harassment, as reduced 
hearing sensitivity and the potential reduced opportunities to detect 
important signals (conspecific communication, predators, prey) may 
result in changes in behavior patterns that would not otherwise occur.
    The Navy's construction activities include the use of continuous 
(vibratory pile-driving) and impulsive (impact pile-driving) sources, 
and therefore the RMS SPL threshold of 160 dB re 1 [mu]Pa is applicable 
for impulsive noise. For continuous noise, the RMS SPL

[[Page 6707]]

threshold of 129.6 dB re 1 [mu]Pa is applicable as a de facto 
harassment threshold, based upon measured noise data for San Diego Bay 
as referenced in the Description of Activity section in the notice for 
the proposed IHA (87 FR 68442, November 15, 2022).
    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). The Navy's 
activity includes the use of impulsive (impact hammer) and non-
impulsive (vibratory hammer) 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: 
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 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 [mu]Pa, and weighted cumulative sound
  exposure level (LE,) has a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to be
  more reflective of International Organization for Standardization standards (ISO, 2017). The subscript
  ``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within the
  generalized hearing range of marine mammals (i.e., 7 Hz to 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 by sound generated by the primary 
components of the project (i.e., impact and vibratory pile driving).
    In order to calculate distances to the Level A harassment and Level 
B harassment thresholds for the methods and piles being used in this 
project, the Navy used acoustic monitoring data from various similar 
locations to develop source levels for the different pile types, sizes, 
and methods planned for use (Table 4).

                                             Table 4--Source Levels for Removal and Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Peak sound
                                                             pressure (dB    Mean maximum       SEL (dB re 1
               Method                    Pile size/type      re 1 [mu]Pa)   RMS SPL (dB re    [mu]Pa2 sec) \1\                    Source
                                                                  \1\        1 [mu]Pa) \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Pile Removal Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Extraction...............  18'' Octagonal         ..............         \3\ 162  ...................  NAVFAC SW, 2022.
                                      Concrete \2\.
                                     18'' Steel Pipe......  ..............         \4\ 156  ...................  Denes et al., 2016.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Pile Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving................  24'' Octagonal                    188             176                  166  Caltrans, 2020.
                                      Concrete.
                                     14'' Square Concrete.             183             166                  154  Caltrans, 2020.
Vibratory Hammer...................  6'' Round Steel \5\..             171             155                  155  Illingworth and Rodkin, 2007.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ As measured, or calculated, at 10 m (33 ft).
\2\ In the absence of information on vibratory extraction of 18-inch octagonal concrete piles, source data from 20-inch concrete square piles NAVFAC SW
  (2022) was used as a proxy source level.
\3\ The maximum mean calculated source value for 20-inch square concrete piles (NAVFAC SW, 2022) was 162 dB RMS based on unpublished data from the Pier
  6 Replacement Project.
\4\ Table 20 in Denes et al. (2016) records a value of 152.4 dB RMS at 17 m (56 ft) for vibratory extraction. This data point, and a transmission loss
  of 15LogR, was used to back-calculate a value of 155.9 dB RMS at 10 m (33 ft) (rounded to 156 dB RMS).
\5\ In the absence of information on vibratory installation of 6-inch round steel piles, source data from 12-inch round steel piles (Illingworth &
  Rodkin, 2017) was used as a proxy source level.
Abbreviations: [mu]Pa = microPascal; dB = decibel; RMS = root mean square; SPL = sound pressure level; m= meters; SEL = sound exposure level.


[[Page 6708]]

Level B Harassment Zones

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

TL = B * Log10 (R1/R2),

where

TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for the Navy's activities. The Level B harassment zones and 
areas of zones of influence (ZOIs) for the Navy's activities are shown 
in Table 5.

                        Table 5--Distance to Level B Harassment Thresholds and ZOI Areas
----------------------------------------------------------------------------------------------------------------
                                                                                   Projected radial distance to
                                                                    Maximum RMS    Level B harassment thresholds
                Method                       Pile size/type        SPL (dB re 1     and ensonified area \1\ \2\
                                                                    [mu]Pa) \1\  -------------------------------
                                                                                    Distance m      Area km\2\
----------------------------------------------------------------------------------------------------------------
                                             Pile Removal Activities
----------------------------------------------------------------------------------------------------------------
Vibratory Extraction..................  18'' Octagonal Concrete.             162           1,445            3.13
                                        18'' Steel Pipe.........             156             575            0.68
----------------------------------------------------------------------------------------------------------------
                                          Pile Installation Activities
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving \3\...............  24'' Octagonal Concrete.             176             117           0.041
Impact Pile Driving...................  14'' Square Concrete....             166              25           <0.01
Vibratory Hammer......................  6'' Round Steel.........             155             494            0.45
----------------------------------------------------------------------------------------------------------------
\1\ The Level B ZOIs for continuous pile removal and installation activities are based on the distance for noise
  to decay to ambient levels (129.6 dB re 1[mu]Pa), while 160 dB was used for impulsive sound.
\2\ Assumes Practical Spreading Loss.
\3\ With or without High[hyphen]pressure Water Jetting.
Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, km\2\ = square kilometers, m
  = meters, ft = feet, RMS = root mean square, ZOI = Zone of Influence.

Level A Harassment Zones

    The ensonified area associated with Level A harassment is more 
technically challenging to predict due to the need to account for a 
duration component. Therefore, NMFS developed an optional User 
Spreadsheet tool to accompany the Technical Guidance that can be used 
to relatively simply predict an isopleth distance for use in 
conjunction with marine mammal density or occurrence to help predict 
potential takes. We note that because of some of the assumptions 
included in the methods underlying this optional tool, we anticipate 
that the resulting isopleth estimates are typically going to be 
overestimates of some degree, which may result in an overestimate of 
potential take by Level A harassment. However, this optional tool 
offers the best way to estimate isopleth distances when more 
sophisticated modeling methods are not available or practical. For 
stationary sources, such as pile installation or 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 
would be expected to incur PTS. The isopleths generated by the User 
Spreadsheet used the same TL coefficient as the Level B harassment zone 
calculations (i.e., the practical spreading value of 15). Inputs used 
in the User Spreadsheet (e.g., number of piles per day, duration and/or 
strikes per pile) are presented in Table 1 of the notice for the 
proposed IHA (87 FR 68442, November 15, 2022). The maximum RMS SPL/SEL 
SPL and resulting isopleths are reported below in Table 6. The maximum 
RMS SPL value was used to calculate Level A harassment isopleths for 
vibratory pile driving and extraction activities, while the single 
strike SEL SPL value was used to calculate Level A isopleths for impact 
pile driving activities.

                                                   Table 6--Distances to Level A Harassment Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Single strike                       Project distances to Level A
                                                                     Maximum RMS    SEL (dB re 1   Duration (hrs/              thresholds (m)
                Method                        Pile size/type        SPL (dB re 1   [mu]Pa\2\ sec)       day)      --------------------------------------
                                                                     [mu]Pa) \1\         \1\                            MF           PW           OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                 Pile Removal Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Extraction..................  18'' Octagonal Concrete               162             N/A            1.25          0.8          5.6          0.4
                                         \2\.
                                        18'' Steel Pipe..........         \2\ 156             N/A            0.25          0.1          0.8          0.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                              Pile Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving...................  24'' Octagonal Concrete..             176             166            1.33          4.1     \3\ 62.4          4.5
                                        14'' Square Concrete.....             166             154            0.25          0.2          2.5          0.2
Vibratory Hammer......................  6'' Round Steel..........             155             155            0.07          0.0          0.3          0.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ As measured at 10 m (33 ft.).

[[Page 6709]]

 
\2\ Table 20 in Denes et al. (2016) records a value of 152.4 dB RMS at 17 m (56 ft.) for vibratory extraction. This data point, and a transmission loss
  of 15LogR, was used to back[hyphen]calculate a value of 156 dB RMS at 10 m (33 ft.).
\3\ Value is greater than the standard shutdown zone of 20 m (see Mitigation section) and will be monitored as shutdown zone to ensure no Level A takes
  of harbor seals or northern elephant seals occur during impact pile driving of 24-inch octagonal concrete piles.
Abbreviations: RMS = root mean square, dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters, ft = feet, SEL = sound exposure
  level, MF = mid-frequency cetaceans, PW = phocid pinnipeds, OW = otariid pinnipeds.

Marine Mammal Occurrence

    In this section, we provide information about the occurrence of 
marine mammals, including density or other relevant information that 
will inform the take calculations. Unless otherwise specified, the term 
``pile driving'' in this section, and all following sections, may refer 
to either pile installation or removal. NMFS has carefully reviewed the 
Navy's analysis and concludes that it represents an appropriate and 
accurate method for estimating incidental take that may be caused by 
the Navy's activities.
    Daily occurrence estimates of marine mammals in the project area 
are based upon the Year 4 IHA monitoring report from the Fuel Pier 
Replacement Project (NAVFAC SW, 2017b). Year 4 is expected to be most 
representative of typical species occurrences as this monitoring period 
had the highest number of activity days and the highest average number 
of animals observed per day for the three most common species in the 
area (California sea lion, harbor seal, bottlenose dolphin), with the 
exception of Year 2. However, Year 2 was an El Ni[ntilde]o year and not 
considered representative of typical species occurrences. The Year 2 
monitoring report data was used for any species not observed in Year 4 
(common dolphin, Pacific white-sided dolphin, northern elephant seal) 
(NAVFAC SW, 2015) (Table 7). Years 1, 3, and 5 included significantly 
less monitoring effort than Years 2 and 4, and may also not be 
representative of typical species richness and occurrences.

                Table 7--Total and Daily Species Occurrences During Years 2 and 4 IHA Monitoring
----------------------------------------------------------------------------------------------------------------
                                                    Year 2 IHA (100 monitoring      Year 4 IHA (152 monitoring
                                                        days; El Nino year)                    days)
                     Species                     ---------------------------------------------------------------
                                                                    Average per                     Average per
                                                  Total observed        day       Total observed        day
----------------------------------------------------------------------------------------------------------------
California sea lion.............................           7,507            75.1           2,263          * 14.9
Harbor seal.....................................             248             2.5              88           * 0.6
Bottlenose dolphin..............................             695               7              67           * 0.4
Common dolphin..................................             850           * 8.5             N/a             N/a
Pacific white-sided dolphin.....................              27           * 0.3             N/a             N/a
Northern elephant seal..........................           \1\ 1           \1\ 1             N/a             N/a
----------------------------------------------------------------------------------------------------------------
* Mean estimate used for daily occurrences for current analysis.
\1\ Same individual hauled out each day.

    Year 4 monitoring consisted of the longest effort of all 5 IHA 
years for the Navy Fuel Pier Replacement Project, and daily occurrence 
estimates for California sea lions, harbor seals, and bottlenose 
dolphins were selected from this year. Common dolphins, Pacific white-
sided dolphins, and northern elephant seals were not sighted in Year 4; 
however, these species were sighted in Year 2 monitoring. Pacific 
white-sided dolphins were only sighted during this year. Daily 
occurrence estimates for common dolphins and Pacific white-sided 
dolphins were selected from Year 2. Only one northern elephant seal was 
sighted during the Year 2 monitoring, and the same individual was 
hauled out each day. Using a daily occurrence estimate from past 
monitoring was, therefore, not an accurate approach for estimating 
occurrence of northern elephant seals. Past monitoring efforts, 
including the one northern elephant seal sighted during Year 2 
monitoring and a sighting north of the project area, (McConchie, 2015; 
NAVFAC SW, 2015) documented a total of two juvenile northern elephant 
seals in the project area, as described in the Description of Marine 
Mammals in Areas of Specified Activities section in the proposed IHA 
(87 FR 68442, November 15, 2022). Due to increasing stock numbers, 
there is a reasonable probability that this species could be sighted in 
the project area during construction activities. Instead of using past 
monitoring data to estimate daily occurrence, it is expected that two 
northern elephant seals may be observed in the project area during 
construction activities, based upon previous sighting data. The Navy 
added a buffer of five seals to this estimate for a total of seven 
expected elephant seals in the area during construction activities, and 
NMFS agrees with this approach.
    Monitoring during Year 4 yielded an observation of 2,263 California 
sea lions over the course of the 152-day monitoring period. These 
observations equate to an average of 14.9 California sea lions observed 
per day, and approximately 15 California sea lions expected to be in 
the vicinity of Pier 302, when this estimate is rounded.
    Based upon monitoring during Year 4, 88 harbor seals were observed 
over the course of the 152-day monitoring period. These observations 
equate to an average of 0.6 harbor seals observed per day, and 
approximately 1 seal per day expected to be in the vicinity of Pier 302 
when this estimate is rounded.
    Monitoring during Year 4 yielded an observation of 67 bottlenose 
dolphins in the project area over the course of the 152-day monitoring 
period. This observation equates to an average of 0.4, or 1 if rounded, 
bottlenose dolphins expected to be in the vicinity of Pier 302 each day 
of the construction activities.
    During Year 2 monitoring, 850 common dolphins were sighted in the 
project area over the course of the 152-day monitoring period. This 
equates to an average of 8.5 common dolphins observed per day. When 
rounded to the nearest whole number, 9.0 individuals are expected to be 
sighted per day in the vicinity of Pier 302.
    Monitoring during Year 2 documented 7 sightings of Pacific white-
sided dolphins, comprising 27 individuals, with an average of 0.28 
individuals sighted per day of monitoring. Rounding this estimate to 
the nearest whole number leads to 1.0 individual per day to be expected 
to be

[[Page 6710]]

in the vicinity of Pier 302 during the construction activities.

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.
    Daily occurrence estimates were multiplied by the number of days of 
pile removal and installation (32 days) to calculate estimated take by 
Level B harassment of California sea lions, harbor seals, bottlenose 
dolphins, common dolphins, Pacific white-sided dolphins, and northern 
elephant seals (Table 8).

            Table 8--Authorized Takes by Level B Harassment and Percent of Stock Authorized for Take
----------------------------------------------------------------------------------------------------------------
                                                           Expected daily    Authorized take     Percentage of
                        Species                               average           by Level B      stock authorized
                                                            individuals         harassment          for take
----------------------------------------------------------------------------------------------------------------
California sea lion \1\................................                 15                480               0.19
Harbor seal \1\........................................                  1                 32               0.10
Bottlenose dolphin \1\.................................                  1                 32                7.1
Common dolphin (long and short beaked) \2\.............                  9                288             * 0.35
Pacific white-sided dolphin \2\........................                  1                 32               0.09
Northern elephant seal.................................              (\3\)                  7              0.004
----------------------------------------------------------------------------------------------------------------
\1\ Average daily counts based on observations during Year 4 Fuel Pier Replacement Project Monitoring (NAVFAC
  SW, 2017b).
\2\ Average daily counts based on observations during Year 2 Fuel Pier Replacement Project Monitoring (NAVFAC
  SW, 2015).
\3\ Expected potential of two northern elephant seals over the duration of project activity with a +5 buffer for
  Level B Take.
* Percent population calculated for each stock of common dolphins. Percentage in the table represents the
  percent of take of long-beaked common dolphins as this would be a greater percentage than if all take were
  attributed to short-beaked common dolphins (0.03 percent).

    By using the sighting-based approach, take values are not affected 
by the estimated harassment distances from Tables 5 and 6. Given the 
very small Level A harassment isopleths for all species and mitigation 
measures, no take by Level A harassment is anticipated or authorized.

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 (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
    Before the commencement of in-water construction activities, the 
Navy will establish shutdown zones for all activities. The purpose of a 
shutdown zone is 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). During all in-
water construction activities, the Navy will implement a standard 20 m 
(66 ft) shutdown zone, with the exception of a 70 m (230 ft) zone for 
phocids during the use of impact pile driving for the 24-inch octagonal 
concrete piles. These distances exceed the estimated Level A harassment 
distances (Table 10). During the impact installation of the 24-inch 
octagonal concrete piles, the shutdown zone for phocids will be 
buffered to 70 m (230 ft) to encompass the Level A harassment zone. 
Adherence to this expanded shutdown zone will avoid the potential for 
the take of phocids by Level A harassment during impact pile driving. 
If a marine mammal enters a buffered shutdown zone, in-water activities 
will be stopped until visual confirmation that the animal has left the 
zone or the animal is not sighted for 15 minutes.
    All marine mammals will be monitored in the Level B harassment 
zones and throughout the area as far as visual monitoring can take 
place. If a marine mammal enters the Level B harassment zone, in-water 
activities will continue and the animal's presence within the estimated 
harassment zone will be documented.
    The Navy will also establish shutdown zones for all marine mammals 
for which take has not been authorized or for which incidental take has 
been authorized, but the authorized number of takes has been met. These 
zones are equivalent to the Level B harassment zones for each activity. 
If a marine mammal species not covered under this IHA enters the 
shutdown zone, all in-water activities will cease until the animal 
leaves the zone or has not been observed for at least 1 hour, and NMFS 
will be notified about species and precautions taken. Pile removal will 
proceed if the non-IHA species is observed to leave the Level B 
harassment zone or if 1 hour has passed since the last observation.
    If shutdown and/or clearance procedures would result in an imminent 
safety concern, as determined by the Navy, the in-water activity will 
be allowed to continue until the safety concern has been addressed, and 
the animal will be continuously monitored. The Navy Point of Contact 
(POC) will be consulted before re-commencing activities.

[[Page 6711]]



                              Table 9--Shutdown Zones and Level B Harassment Zones
----------------------------------------------------------------------------------------------------------------
                                                               Shutdown zones m (ft)                  Level B
            Method               Pile size/type  ------------------------------------------------   harassment
                                                        MF              PW              OW         zones m (ft)
----------------------------------------------------------------------------------------------------------------
                                             Pile Removal Activities
----------------------------------------------------------------------------------------------------------------
Vibratory Extraction..........  18'' Octagonal           20 (66)         20 (66)         20 (66)   1,445 (4,742)
                                 Concrete.
                                18'' Steel Pipe.         20 (66)         20 (66)         20 (66)     575 (1,888)
----------------------------------------------------------------------------------------------------------------
                                          Pile Installation Activities
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving...........  24'' Octagonal           20 (66)    \1\ 70 (230)         20 (66)       117 (383)
                                 Concrete.
                                14'' Square              20 (66)         20 (66)         20 (66)         25 (82)
                                 Concrete.
Vibratory Hammer..............  6'' Round Steel.         20 (66)         20 (66)         20 (66)     494 (1,619)
----------------------------------------------------------------------------------------------------------------
\1\ Level A ZOI buffered from 62.5 m up to 70 m.

Protected Species Observers

    The placement of protected species observers (PSOs) during all pile 
driving activities (described in the Monitoring and Reporting section) 
will ensure that the entire shutdown zone is visible. Should 
environmental conditions deteriorate such that the entire shutdown zone 
would not be visible (e.g., fog, heavy rain), pile driving will be 
delayed until the PSO is confident marine mammals within the shutdown 
zone could be detected.

Pre-Activity Monitoring

    Prior to the start of daily in-water construction activity, or 
whenever a break in pile driving of 30 minutes or longer occurs, PSOs 
will observe the shutdown 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 zones listed in 
Table 10, pile driving activity will be delayed or halted. If work 
ceases for more than 30 minutes, the pre-activity monitoring of the 
shutdown zones will commence. A determination that the shutdown zone is 
clear must be made during a period of good visibility (i.e., the entire 
shutdown zone and surrounding waters must be visible to the naked eye).

Soft-Start Procedures

    Soft-start procedures provide additional protection to marine 
mammals by providing warning and/or giving marine mammals a chance to 
leave the area prior to the hammer operating at full capacity. For 
impact pile driving, contractors will be required to provide an initial 
set of three strikes from the hammer at reduced energy, followed by a 
30-second waiting period, then two subsequent reduced-energy strike 
sets. Soft-start 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.
    Based on our evaluation of the applicant's measures, NMFS has 
determined that the mitigation measures provide the means of effecting 
the least practicable impact on the affected species or stocks and 
their habitat, paying particular attention to rookeries, mating 
grounds, and areas of similar significance.

Monitoring and Reporting

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

Visual Monitoring

    Marine mammal monitoring during pile driving activities will be 
conducted by PSOs meeting NMFS' following requirements:
     Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods will be used;
     At least one PSO will have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for prior experience performing 
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization; and
     A minimum of two PSOs must be on duty for all in-water 
construction activities. A lead observer or monitoring coordinator must 
be designated to

[[Page 6712]]

coordinate monitoring and log project and monitoring activity data. The 
lead observer must have prior experience performing the duties of a PSO 
during construction activity pursuant to a NMFS-issued incidental take 
authorization.
     PSOs must be approved by NMFS prior to beginning any 
activity subject to this IHA.
    PSOs will have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    The Navy will have at least two PSOs stationed at the best possible 
vantage points in the project area to monitor during all pile driving 
activities. If a PSO sights a marine mammal in the shutdown zone, the 
PSO must alert the ``command'' PSO to notify the equipment operator to 
shut down. If the ``command'' PSO does not respond, any PSO has the 
authority to notify the need for a shutdown. If the ``command'' PSO 
calls for a shutdown, the ``command'' PSO will let the contractor know 
when activities can re-commence. Additional PSOs may be employed during 
periods of low or obstructed visibility to ensure the entirety of the 
shutdown zones are monitored. A marine mammal monitoring plan has been 
submitted to NMFS for approval.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving activities, or 60 
days prior to a requested date of issuance of any future IHAs for the 
project, or other projects at the same location, whichever comes first. 
A final report must be prepared and submitted within 30 calendar days 
following receipt of any NMFS comments on the draft report. If no 
comments are received from NMFS within 30 calendar days of receipt of 
the draft report, the report shall be considered final. All draft and 
final monitoring reports must be submitted to 
[email protected] and [email protected]. The marine 
mammal monitoring report will include an overall description of work 
completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report will include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including: (a) How many and what type of piles were 
driven or removed and the method (i.e., impact or vibratory); and (b) 
the total duration of time for each pile (vibratory driving) number of 
strikes for each pile (impact driving);
     PSO locations during marine mammal monitoring; and
     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.
    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. 
Specifically, PSOs will record the following:
     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 location of each observed marine mammal 
relative to the pile being driven or hole being drilled for each 
sighting;
     Estimated number of animals (min/max/best estimate);
     Estimated number of animals by cohort (adults, juveniles, 
neonates, group composition, etc.);
     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).
    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, the Navy will report the 
incident to the Office of Protected Resources (OPR) 
([email protected]), NMFS 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, the Navy 
will immediately cease the specified activities until NMFS is able to 
review the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the IHAs. The Navy will not resume their activities until notified 
by NMFS.
    The report will include the following information:
    1. Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
    2. Species identification (if known) or description of the 
animal(s) involved;
    3. Condition of the animal(s) (including carcass condition if the 
animal is dead);
    4. Observed behaviors of the animal(s), if alive;
    5. If available, photographs or video footage of the animal(s); and
    6. 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

[[Page 6713]]

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 discussion of our analysis applies to all 
the species listed in Table 1, given that the anticipated effects of 
this activity on these different marine mammal stocks are expected to 
be similar. There is little information about the nature or severity of 
the impacts, or the size, status, or structure of any of these species 
or stocks that would lead to a different analysis for this activity.
    Level A harassment is extremely unlikely given the small size of 
the Level A harassment isopleths and the required mitigation measures 
designed to minimize the possibility of injury to marine mammals. No 
mortality is anticipated given the nature of the activity.
    Pile installation and removal activities have the potential to 
disturb or displace marine mammals. Specifically, the project 
activities may result in take, in the form of Level A and Level B 
harassment from underwater sounds generated from impact and vibratory 
pile installation, and vibratory pile removal activities. Potential 
takes could occur if individuals move into the ensonified zones when 
these activities are underway.
    The takes from Level B harassment will be due to potential 
behavioral disturbance. No serious injury or mortality is anticipated 
for any stocks presented in this analysis given the nature of the 
activity and mitigation measures designed to minimize the possibility 
of injury. The potential for harassment is minimized through 
construction methods and the implementation of planned mitigation 
strategies (see Mitigation section).
    Take will occur within a limited, confined area of each stock's 
range. Level B harassment will be reduced to the level of least 
practicable adverse impact through use of mitigation measures described 
herein. Further, the amount of take authorized is extremely small when 
compared to stock abundance.
    No marine mammal stocks for which incidental take authorization is 
authorized are listed as threatened or endangered under the ESA or 
determined to be strategic or depleted under the MMPA. The relatively 
low marine mammal occurrences in the area, small shutdown zones, and 
planned monitoring make injury takes of marine mammals unlikely. The 
shutdown zones will be thoroughly monitored before the vibratory pile 
installation and removal begins, and construction activities will be 
postponed if a marine mammal is sighted within the shutdown zone. There 
is a high likelihood that marine mammals will be detected by trained 
observers under environmental conditions described for the project. 
Limiting construction activities to daylight hours will also increase 
detectability of marine mammals in the area. Therefore, the mitigation 
and monitoring measures are expected to eliminate the potential for 
injury and Level A harassment as well as reduce the amount and 
intensity for Level B behavioral harassment. Furthermore, the pile 
installation and removal activities analyzed here are similar to, or 
less impactful than, numerous construction activities conducted in 
other similar locations which have occurred with no reported injuries 
or mortality to marine mammals, and no known long-term adverse 
consequences from behavioral harassment.
    Anticipated and authorized takes are expected to be limited to 
short-term Level B harassment (behavioral disturbance) as construction 
activities will occur over the course of 32 weeks. Effects on 
individuals taken by Level B harassment, based upon reports in the 
literature as well as monitoring from other similar activities, may 
include increased swimming speeds, increased surfacing time, or 
decreased foraging (e.g., Thorson and Reyff, 2006; NAVFAC SW, 2018b). 
Individual animals, even if taken multiple times, will likely move away 
from the sound source and be temporarily displaced from the area due to 
elevated noise level during pile removal. Marine mammals could also 
experience TTS if they move into the Level B monitoring zone. TTS is a 
temporary loss of hearing sensitivity when exposed to loud sound, and 
the hearing threshold is expected to recover completely within minutes 
to hours. Thus, it is not considered an injury. While TTS could occur, 
it is not considered a likely outcome of this activity. Repeated 
exposures of individuals to levels of sounds that could cause Level B 
harassment are unlikely to considerably significantly disrupt foraging 
behavior or result in significant decrease in fitness, reproduction, or 
survival for the affected individuals. In all, there will be no adverse 
impacts to the stock as a whole.
    The project is not expected to have significant adverse effects on 
marine mammal habitat. There are no Biologically Important Areas or 
ESA-designated critical habitat within the project area, and the 
activities will not permanently modify existing marine mammal habitat. 
The activities may cause fish to leave the area temporarily. This could 
impact marine mammals' foraging opportunities in a limited portion of 
the foraging range, however, due to the short duration of activities 
and the relatively small area of affected habitat, the impacts to 
marine mammal habitat are not expected to cause significant or long-
term negative consequences.
    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 would have only 
minor, short-term effects on individuals. The specified activities are 
not expected to impact reproduction or survival of any individual 
marine mammals, much less affect rates of recruitment or survival and 
would therefore not result in population-level impacts.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect any of the species or stocks 
through effects on annual rates of recruitment or survival:
     No serious injury or mortality or Level A harassment is 
anticipated or authorized;
     The specified activity and associated ensonified areas are 
very small relative to the overall habitat ranges of all species;
     Biologically important areas or critical habitat have not 
been identified within the project area;
     The lack of anticipated significant or long-term effects 
to marine mammal habitat;
     The Navy is required to implement mitigation measures to 
minimize impacts, such as PSO observation and shutdown zones of 20 m 
(66 ft); and,
     Monitoring reports from similar work in San Diego Bay have 
documented little to no effect on individuals of the same species 
impacted by the specified activities.
    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 
authorized

[[Page 6714]]

activity will have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted previously, only small numbers of incidental take may be 
authorized under sections 101(a)(5)(A) and (D) of the MMPA for 
specified activities other than military readiness activities. The MMPA 
does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. When the predicted number of 
individuals to be taken is fewer than one-third of the species or stock 
abundance, the take is considered to be of small numbers. Additionally, 
other qualitative factors may be considered in the analysis, such as 
the temporal or spatial scale of the activities.
    The amount of take NMFS has authorized is below one-third of the 
estimated stock abundances for all seven species (refer back to Table 
8). For most requested species, the authorized take of individuals is 
less than 1 percent of the abundance of the affected stock (with 
exception for bottlenose dolphins at 7.1 percent). This is likely a 
conservative estimate because it assumes all takes are of different 
individual animals, which is likely not the case. Some individuals may 
return multiple times in a day, but PSOs will count them as separate 
takes if they cannot be individually identified.
    Based on the analysis contained herein of the authorized 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

    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 Endangered Species Act of 1973 (ESA; 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally whenever we propose to authorize take for 
endangered or threatened species.
    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 the U.S. Navy for the potential 
harassment of small numbers of six marine mammal species incidental to 
construction activities associated with the Naval Base Point Loma Pier 
302 Replacement Project in San Diego, California., provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are followed.

    Dated: January 27, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2023-02107 Filed 1-31-23; 8:45 am]
BILLING CODE 3510-22-P