[Federal Register Volume 86, Number 167 (Wednesday, September 1, 2021)]
[Notices]
[Pages 48986-48998]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2021-18877]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XB327]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Fuel Pier Inboard Pile Removal 
Project in 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 IHA to the United States Navy to incidentally 
harass, by Level B harassment only, marine mammals during pile driving/
removal activities associated with the Fuel Pier Inboard Pile Removal 
Project in San Diego Bay, California.

DATES: This Authorization is effective from January 15, 2022 through 
January 14, 2023.

FOR FURTHER INFORMATION CONTACT: Kelsey Potlock, 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/action/incidental-take-authorization-us-navy-fuel-pier-removal-naval-base-san-diego-california. 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 issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be 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

[[Page 48987]]

``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 February 3, 2021, NMFS received a request from United States 
Navy (Navy) for an IHA to take marine mammals incidental to pile 
driving/removal activities at Naval Base Point Loma in San Diego Bay, 
California. The application was deemed adequate and complete on May 17, 
2021. The Navy's request is for take of a small number of six species 
of marine mammals by Level B harassment only. Neither the Navy nor NMFS 
expects serious injury or mortality to result from this activity and, 
therefore, an IHA is appropriate.
    Naval Base Point Loma provides berthing and support services for 
Navy submarines and other fleet assets. The existing fuel pier 
previously served as a fuel depot for loading and unloading fuel. Naval 
Base Point Loma is the only active Navy fueling facility in southern 
California. The current project is to remove piles that were part of 
the old pier that was replaced over the past few years. This IHA 
includes up to 84 days of in-water pile driving/removal activities.
    NMFS has previously issued incidental take authorizations to the 
Navy for similar activities over the past 8 years at Naval Base Point 
Loma in San Diego 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, 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), and October 1, 
2021 through September 30, 2022 (86 FR 7993, February 3, 2021; Pier 6 
Replacement Project). The Navy has complied with all the requirements 
(e.g., mitigation, monitoring, and reporting) of past IHAs. Monitoring 
reports from these activities are available on NMFS website (https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities).

Description of the Specified Activity

Overview

    The purpose of this project is to remove old piles from the Fuel 
Pier at Naval Base Point Loma to allow for continued Naval Fleet 
readiness activities. More specifically, the in-water construction work 
includes the removal of 409 piles by a variety of techniques (i.e., one 
to two pile clippers, an underwater chainsaw, a diamond wire saw, or a 
vibratory hammer, possibly with assistance from a diver). Concurrent 
pile removal may occur for some piles by using only two pile clippers. 
The piles include an estimated 12 13-inch diameter polycarbonate fender 
piles, 56 14-inch diameter concrete fender piles, and 341 16-inch 
diameter concrete structural piles.
    A detailed description of the planned project is provided in the 
Federal Register notice for the proposed IHA (86 FR 38274; July 20, 
2021). Since that time, no changes have been made to the planned pile 
removal 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 the Monitoring 
and Reporting sections).

Comments and Responses

    A notice of NMFS' proposal to issue an IHA to the Navy was 
published in the Federal Register on July 20, 2021 (86 FR 38274). That 
notice described, in detail, the Navy's activity, the marine mammal 
species that may be affected by the activity, and the anticipated 
effects on marine mammals. During the 30-day public comment period, 
NMFS received public comments from one commenter. The United States 
Geological Survey noted that they have ``no comment at this time''.

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. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    Table 1 lists all marine mammal species with expected potential for 
occurrence in the vicinity of Naval Base Point Loma during the project 
timeframe and summarizes key information, 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's SARs; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments). While no 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 and other threats. For 
taxonomy, we followed the Society for Marine Mammalogy's Committee on 
Taxonomy (2020).
    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's 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's 2019 Pacific SARs (Carretta et al., 2020a) and recently 
finalized 2020 U.S. Pacific SARs (Carretta et al., 2020b). Upon the 
finalizing of the 2020 SARs, none of the stock information for the 
species that are expected to occur in the project area for this project 
has changed. All values presented in Table 1 are the most recent 
available at the time of publication and are available in the 2019 
Pacific SARs and 2020 Pacific SARs (available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports).

[[Page 48988]]



                                                 Table 1--Species Expected to Occur in the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         ESA/MMPA status;    Stock abundance (CV,
             Common name                  Scientific name               Stock             Strategic (Y/N)      Nmin, most recent       PBR     Annual M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
                                                                   Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin..................  Tursiops truncatus.....  California coastal.....  -, -, N             453 (0.06, 3436, 2011)        2.7      >=2.0
Short-beaked common dolphin.........  Delphinus delphis......  California/Oregon/       -, -, N             969,861 (0.17,               8393       >=40
                                                                Washington.                                  839,325, 2014).
Long-beaked common dolphin..........  Delphinus capensis.....  California.............  -, -, N             101,305 (0.49, 68,432,        657     >=35.4
                                                                                                             2014).
Pacific white-sided dolphin.........  Lagenorhynchus           California/Oregon/       -, -, N             26,814 (0.28, 21,195,         191        7.5
                                       obliquidens.             Washington.                                  2014).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion.................  Zalophus californianus.  United States..........  -, -, 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             179,000 (N/A, 81,368,        4882        8.8
                                                                                                             2010).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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 (M/SI) 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.

    For Risso's dolphins (Grampus griseus) and gray whales 
(Eschrichtius robustus), occurrence is such that take is unlikely and 
we have not authorized take of these species.
    A detailed description of the species likely to be affected by the 
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 (86 FR 38274; July 20, 
2021); 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.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    The effects of underwater noise from the Navy's construction 
activities have the potential to result in behavioral harassment of 
marine mammals in the vicinity of the project area. The notice of 
proposed IHA that was published in the Federal Register (86 FR 38274; 
July 20, 2021) included a discussion of the effects of anthropogenic 
noise on marine mammals and the potential effects of underwater noise 
from the Navy's construction on marine mammals and their habitat. That 
information and analysis is incorporated by reference into this final 
IHA determination and is not repeated here; please refer to the notice 
of proposed IHA (86 FR 38274; July 20, 2021).

Estimated Take

    This section provides an estimate of the number of incidental takes 
authorized through this IHA, which will inform both NMFS' consideration 
of ``small numbers'' and the negligible impact determination.
    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 for Level B harassment only, in the form of 
disruption of behavioral patterns and TTS for individual marine mammals 
resulting from exposure to the sounds produced from the underwater 
acoustic sources (i.e., vibratory hammer, single use or concurrent use 
of pile clippers, underwater chainsaw, diamond wire saw). Based on the 
nature of the activity and the anticipated effectiveness of the 
mitigation measures (i.e., PSO monitoring and shutdown zone) discussed 
in detail below in the Mitigation and the Monitoring and Reporting 
sections, Level A harassment is neither anticipated nor will be 
authorized.
    As described previously, no mortality is anticipated or authorized 
for this activity. Below we describe how the take is estimated.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals would be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that would be ensonified above these levels in a day; (3) the density 
or occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these

[[Page 48989]]

basic factors can contribute to a basic calculation to provide an 
initial prediction of 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 
estimate.

Acoustic Thresholds

    NMFS recommends the use of acoustic thresholds that identify the 
received level of underwater sound above which exposed marine mammals 
will be reasonably expected to be behaviorally harassed (equated to 
Level B harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment for non-explosive sources--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 (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [mu]Pa (root mean square (rms)) for 
continuous (e.g., vibratory hammer) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., impact hammers (pile-driving)) or 
intermittent (e.g., scientific sonar) sources.
    The Navy's pile driving/removal activities includes the use of 
stationary, non-impulsive, and continuous noise sources (vibratory 
hammer, diamond wire saw, underwater chainsaw, single use or concurrent 
use of pile clippers), and therefore the 120 dB re 1 [mu]Pa (rms) is 
applicable. However, as discussed above, the Navy measurements support 
an ambient noise estimate of 129.6 dB re 1 [mu]Pa (rms) in the project 
area. Accordingly, we have adjusted the standard Level B harassment 
threshold of 120 dB to 129.6 dB, as it likely provides a more realistic 
and accurate basis for predicting Level B harassment in the San Diego 
Bay area.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (NMFS, 2018a) 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 pile driving/removal activities includes the use of non-
impulsive (vibratory pile removal and other cutting and removal 
methods) sources.
    These thresholds are provided in Table 2 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2018a Technical Guidance, which may be accessed at 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                  Table 2--Thresholds Identifying the Onset of Permanent Threshold Shift (PTS)
----------------------------------------------------------------------------------------------------------------
                                                    PTS onset acoustic thresholds \1\ (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater).....  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
                                          LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater)....  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
                                          LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
\1\ 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[micro]Pa2s. 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 would be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels, durations, and 
transmission loss coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from this project. Marine 
mammals are expected to be affected via sound generated by the primary 
components of the project (i.e., vibratory pile removal, diamond wire 
saw, single use or concurrent use of pile clippers, and underwater 
chainsaws).
    Vibratory hammers produce constant sound when operating, and 
produce vibrations that liquefy the sediment surrounding the pile, 
allowing it to penetrate to the required seating depth or be withdrawn 
more easily. The actual durations of each method vary depending on the 
type and size of the pile.
    In order to calculate the distance to the Level B harassment sound 
threshold for piles of various sizes being used in this project, the 
Navy used acoustic monitoring data from other locations and projects to 
develop source levels for the various pile types, sizes, and methods of 
removal. Data for the removal methods (i.e., a diamond wire saw, 
individual use or concurrent use of pile clippers, and an underwater 
chainsaw) comes from data gathered at other nearby or related Navy 
projects as reported in their San Diego Noise

[[Page 48990]]

Compendium (NAVFAC SW, 2020). The only exception to this is the sound 
source data for the vibratory hammer, which was sourced from the City 
of Seattle Pier 62 project (Greenbusch Group, 2018). The source levels 
for the pile clippers, single and simultaneous use, and underwater 
chainsaw for this project utilized the mean maximum RMS SPL rather than 
the median sound levels we typically use as this will provide a more 
conservative measure. The diamond wire saw utilized the noise profile 
measurements associated with the removal of 66-inch and 84-inch 
caissons in the Navy Compendium (NAVFAC SW, 2020). The Navy has noted, 
and we agree, that these values are likely much lower in reality as 
this project would remove 16-inch concrete piles instead of the much 
larger variants modeled in the Compendium. However, no recorded data 
currently exists for the wire saws cutting concrete; therefore, we used 
the mean of the source level data from the Navy Compendium. The 
vibratory hammer used the highest average weighted RMS sound level per 
the Seattle Pier 62 project acoustic monitoring report (Greenbusch 
Group, 2018).
    During pile driving/removal activities, there may be times when two 
pile extraction methods (i.e., pile clippers) are used simultaneously. 
The likelihood of such an occurrence is anticipated to be infrequent, 
will depend on the specific methods chosen by the contractor, and will 
be for short durations on that day. In-water pile removal occurs 
intermittently, and it is common for removal to start and stop multiple 
times as each pile is adjusted and its progress is measured. Moreover, 
the Navy has multiple options for pile removal depending on the pile 
type and condition, sediment, and how stuck the pile is, etc. When two 
continuous noise sources, such as pile clippers, have overlapping sound 
fields, there is potential for higher sound levels than for non-
overlapping sources. When two or more pile removal methods (pile 
clippers) are used simultaneously, and the sound field of one source 
encompasses the sound field of another source, the sources are 
considered additive and combined using the following rules (see Table 
3). For addition of two simultaneous methods, the difference between 
the two sound source levels (SSLs) is calculated, and if that 
difference is between 0 and 1 dB, 3 dB are added to the higher SSL; if 
difference is between 2 or 3 dB, 2 dB are added to the highest SSL; if 
the difference is between 4 to 9 dB, 1 dB is added to the highest SSL; 
and with differences of 10 or more dB, there is no addition (NMFS, 
2018b; WSDOT, 2018).

 Table 3--Rules for Combining Sound Levels Generated During Pile Removal
------------------------------------------------------------------------
                               Level A harassment    Level B harassment
      Difference in SSL             isopleths             isopleths
------------------------------------------------------------------------
0 or 1 dB...................  Add 3 dB to the       Add 3 dB to the
                               higher source level.  higher source
                                                     level.
2 or 3 dB...................  Add 2 dB to the       Add 2 dB to the
                               higher source level.  higher source
                                                     level.
4 to 9 dB...................  Add 1 dB to the       Add 1 dB to the
                               higher source level.  higher source
                                                     level.
10 dB or more...............  Add 0 dB to the       Add 0 dB to the
                               higher source level.  higher source
                                                     level.
------------------------------------------------------------------------
Source: Modified from USDOT, 1995; WSDOT, 2018; and NMFS, 2018b.
Note: dB = decibel; SSL = sound source Level.

Level A Harassment Zones

    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of Level A harassment take. However, these tools offer the 
best way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources, such as the 
localized pile removal activities discussed above, the NMFS User 
Spreadsheet predicts the distance at which, if a marine mammal remained 
at that distance the whole duration of the activity, it will incur PTS.
    The Navy provided estimates to NMFS for the duration of sound 
exposure for each pile removal activity. The durations used in this 
project for each pile removal method were noted as ``conservative 
estimates that are greater than durations observed in the San Diego 
Noise Compendium'' by the Navy. In discussions with NMFS, the Navy has 
explained that the average durations found in the IHA application and 
Compendium were based around data collected in the from the old Fuel 
Pier demolition projects (NAVFAC SW 2014, 2015a, 2016, 2017a, 2017b, 
2018a, and 2018b). These values were adjusted to account for either the 
maximum amount of time the activity could occur (i.e., pile clippers), 
a duration that is greater than the maximum (i.e., underwater chainsaw 
and vibratory hammer), or an adjusted duration based on the removal of 
a smaller pile (i.e., diamond wire saw) in order to provide somewhat 
more conservative measurements using real-world data. These values were 
likely considered more realistic for past projects and could safely be 
assumed as conservative for this project as the Navy will be cutting 
smaller sized piles. The Navy also performed an ``ultra-conservative'' 
hypothetical review by modeling a 1-hour duration for each pile being 
removed. Using a rate of five piles removed per day, the resulting 
Level A harassment isopleths were still smaller than the 20 m shutdown 
zone the Navy plans to implement. Further information on durations can 
be found in the Compendium (NAVFAC SW, 2020).
    All inputs used in the User Spreadsheet are reported below in Table 
4.

[[Page 48991]]



                        Table 4--Project Sound Source Levels and User Spreadsheet Inputs
----------------------------------------------------------------------------------------------------------------
                                                                                    Duration of
                                                                   Source level        sound       Transmission
             Activity \3\                    Type of source        (dB RMS) \1\     production         loss
                                                                                    (hours) \2\     coefficient
----------------------------------------------------------------------------------------------------------------
Vibratory pile driving................  Stationary source, non-              152          0.1667              15
                                         impulsive, continuous.
13-inch polycarbonate pile removal....  Stationary source, non-              154            0.42            11.7
                                         impulsive, continuous.
16-inch concrete pile removal.........  Stationary source, non-              147            0.42              15
                                         impulsive, continuous.
16-inch concrete pile clipping with     Stationary source, non-              150            0.42              15
 +3dB adjustment for two simultaneous    impulsive, continuous.
 pile clippers.
16-inch concrete pile removal using     Stationary source, non-              150            0.83              15
 hydraulic chainsaw (underwater          impulsive, continuous.
 chainsaw).
Wire saw for caisson cutting..........  Stationary source, non-              156             1.7              15
                                         impulsive, continuous.
----------------------------------------------------------------------------------------------------------------
\1\ All of these sound source data for use in the Level A and B harassment threshold modeling were calculated
  from acoustic data found in the 2020 San Diego Noise Compendium (NAVFAC SW, 2020); the only exception is the
  vibratory hammer source level which was sourced from the City of Seattle Pier 62 Project (Greenbusch Group,
  2018).
\2\ The User Spreadsheet inputs assumed 5 piles will be removed within a single 24-hour period using data from
  the Navy's Compendium (NAVFAC SW, 2020).
\3\ All activities utilized a weighting factor adjustment (kHz) of 2.5.

    For this project, we modeled sound propagation using the practical 
spreading value of 15 for transmission loss for all pile removal 
methods, except for the removal of the 13-inch polycarbonate piles. For 
this, 11.7 was used as the transmission loss coefficient as this value 
was a calculated measure from recorded data that was fit with a 
logarithmic trendline during the clipping of a 13-inch round concrete 
pile using small pile clippers in February 2017 at the old Fuel Pier 
(NAVFAC SW, 2020). The above input scenarios lead to PTS isopleth 
distances (Level A harassment thresholds) of less than 1 meter for all 
methods and piles (Table 5).

           Table 5--Modeled and Expected Level A and B Harassment Isopleths (Using Two Methods) for the Pile Type and Removal Method (Meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                           (A) Projected distances to Level A harassment    (B) Projected distances to
                                                                                           isopleth \3\                     Level B harassment isopleth
                                                                         ------------------------------------------------               \5\
             Pile information                      Removal method                                                        -------------------------------
                                                                                                                             Practical
                                                                                MF              PW              OW        spreading loss  Real-time data
                                                                                                                               model
--------------------------------------------------------------------------------------------------------------------------------------------------------
13-inch polycarbonate pile................  One pile clipper............             0.0             0.0             0.0         \5\ 423             350
14-inch, 16-inch concrete piles...........  One pile clipper............             0.0             0.0             0.0             145         \5\ 250
14-inch, 16-inch concrete pile \1\........  Two pile clippers...........             0.0             0.0             0.0             229         \5\ 250
14-inch, 16-inch concrete pile............  Underwater chainsaw.........             0.0             0.1             0.0         \5\ 229              45
14-inch, 16-inch concrete pile............  Diamond wire saw............             0.1             0.7             0.0         \5\ 575             350
14-inch, 16-inch concrete pile............  Vibratory hammer............             0.1             0.9             0.1         \5\ 311           (\4\)
--------------------------------------------------------------------------------------------------------------------------------------------------------
MF = mid-frequency cetaceans, PW = phocid pinnipeds, OW = otariid pinnipeds.
\1\ The Navy added an adjustment of +3 dB to the noise of a single pile clipper (147 dB RMS re 1[mu]Pa) and increased to 150 dB RMS re 1[mu]Pa where two
  clippers are used simultaneously (Kinsler et al., 2000). This adjustment is consistent with NMFS guidance for simultaneous sound sources.
\2\ All sound sources were taken from the Compendium of Underwater and Airborne Sound Data during Pile Installation and In-Water Demolition Activities
  in San Diego Bay, California (San Diego Noise Compendium; NAVFAC SW, 2020), with exception of the vibratory hammer which was sourced from the City of
  Seattle Pier 62 Project (Greenbusch Group, 2018).
\3\ Because of the small sizes of the Level A harassment isopleths (as determined by NMFS's User Spreadsheet Tool) and the mitigation methods
  implemented during this project, neither NMFS nor the Navy expects Level A harassment (and, therefore, take) to occur.
\4\ No information available.
\5\ Designate the most conservative isopleths NMFS will use for the subsequent Level B take analyses and Level B harassment impact zones.

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 activity in the absence of specific

[[Page 48992]]

modeling. We used the Navy's realistic, site-specific averaged median 
ambient noise measurement of 129.6 dB RMS re 1 [mu]Pa for the Level B 
harassment threshold in San Diego Bay (NAVFAC SW, 2020). It should be 
noted that based on the bathymetry and geography of San Diego Bay, 
sound will not reach the full distance of the Level B harassment 
isopleths in all directions.
    To determine the most appropriate and conservative Level B 
harassment isopleths, we compared two methods and selected the isopleth 
between each method that was largest, thus providing the greatest 
coverage for the Level B harassment zone. Level B harassment isopleths 
were considered appropriate based on the distance where the source 
level reached the 129.6 dB ambient value. The two methods compared the 
empirical data provided in the Navy's Compendium for work at Naval Base 
Point Loma (NAVFAC SW, 2020) with the Practical Spreading Loss model 
using a transmission loss coefficient of 15, as described above. 
Results of each method are shown in Table 5 and described below.
    For the Compendium method, the average and maximum sound levels (in 
dB re 1 [micro]Pa) measured at the source (10 m) and then at various 
far-field distances typically showed a monotonic decline in average and 
maximum sound pressure levels distance increased. The Navy chose to use 
the average values for two main reasons: (1) Consistency with using the 
average median (L50) ambient values; and (2) average source values were 
used for the same activities in the Pier 6 project nearby (86 FR 7993, 
February 3, 2021). However, some level of variability in the recorded 
sound pressure levels was present where noise levels will drop to 
ambient levels and then increase to higher levels at greater distances. 
An example of this will be measurements for the 84-inch caisson removal 
by a single wire saw. At source (10 m), the average and maximum source 
levels exceeded the ambient noise levels for both measurements at the 
source (136.1 and 141.4 dB re 1 [micro]Pa; 140.9 and 146.5 dB re 1 
[micro]Pa, respectively). At far-field distances (>20 m), the averages 
show variability with a gradual decline and then a subsequent increase, 
i.e., 140.8 dB re 1 [micro]Pa at 20 m and 134.8 at 40 m, then 137.1 dB 
re 1 [micro]Pa at 60 m. The distance where sound was measured ends at 
283 m from the source with an average level of 130.3 dB re 1 [micro]Pa 
and a maximum level of 137.0 dB re 1 [micro]Pa, both in exceedance of 
the ambient level. These instances could be attributed to the presence 
of vessel traffic at distance from the acoustic recorder, causing some 
interference or competing background noise to the pure sound 
measurements of the wire saw or to random variation from other acoustic 
effects related to the specific location of the hydrophone. In any 
event, the distance at which the sound declined below ambient was not 
always entirely clear and the Navy was unable to develop a consistent 
criterion to determine the likely distance at which sound decreased 
below ambient or to account for factors like the topography or 
hydrophone location. Therefore we describe the analysis of the Navy 
Compendium's field data for each pile removal method individually 
below.
    For the 13-inch polycarbonate piles with pile clippers the Navy 
believes that at between 300 and 400 m (984 to 1,312 ft), a majority of 
the background noise measured is directly related to traffic transiting 
to/from the Everingham Brothers Bait Company (EBBCO) bait barges which 
are to the southwest of the project area. Boat traffic for that 
specific route ranges from small boats to large recreational/commercial 
fishing vessels and traffic is nearly constant throughout the day. 
Because of that, the Navy believes values between those distances will 
likely be artificially high relative to the transmission loss 
associated with the project-related activities. Furthermore, in the 
turning basin the slope rises up from a max depth of 20.12 m (66 ft) to 
11.58 m (38 ft) between 200 to 400 m (656.17 to 1,312.34 ft). As is 
evidenced by the Navy's acoustical model for south-central San Diego 
Bay (see the Naval Base Point Loma Pier 6 project at https://www.fisheries.noaa.gov/action/incidental-take-authorization-naval-base-san-diego-pier-6-replacement-project-san-diego), changes in bathymetry 
(i.e., channel walls) act as noise attenuators. Therefore, the Navy 
estimated the Level B harassment isopleth for this source at 350 m, 
smaller than the Practical Spreading Loss model prediction of 423 m. 
Given the uncertainty discussed above, we used the 423 m distance for 
the Level B harassment isopleth.
    For the one pile clipper on concrete pile source, the Navy again 
believes the Compendium data were influenced by boat activity and 
topography of the channel. In this particular case, Table 39 of the 
Compendium shows that the average dB level at 215 m was 129.0 dB RMS. 
However, the two measurements at 309 m were split, one higher and one 
lower than the value at 215 m. The Navy decided that ``Understanding 
that acoustics is not an ``exact science,'' we evaluated the data and 
chose a distance (250 m) that fit the data (average noise levels 
dropped below 129.6 dB at between 215 and 309 m).'' As this 250 m 
distance exceeded the practical spreading loss model distance of 145 m, 
we chose the 250 m distance for the Level B harassment isopleth.
    For the two pile clipper on concrete pile source the Navy decided 
that ``Because the project footprint is parallel to the shoreline, we 
created a monitoring zone that used a source level of 150 dB, but at 
two points at the extreme north and south of the project footprint (see 
Fig 6-3 in the IHA application) because we felt that this would 
generate a more conservative'' zone that led to an estimate of the 
Level B harassment isopleth of 250 m. As this 250 m distance exceeded 
the practical spreading loss model distance of 229 m, we chose the 250 
m distance for the Level B harassment isopleth.
    For the underwater chainsaw the Navy noted the ``transmission loss 
(27logR) was steep when compared to other equipment, but the source 
value was in line with the pile clippers. Because of the very steep TL 
value, we looked at the perceived far-field data points for the clipper 
activities and chose a distance that was in-between the drop off to 
ambient for the chainsaw (from 26 to 45 m) and the clippers (250 m).'' 
The Navy estimated the Level B harassment isopleth for this source at 
45 m, smaller than the Practical Spreading Loss model prediction of 229 
m. Given the uncertainty discussed above, we used the 229 m distance 
for the Level B harassment isopleth.
    For the diamond wire saw the Navy again believes the Compendium 
data were influenced by boat activity and topography of the channel. 
The available data are from caissons which consist of 1.5 inch thick 
hardened steel shells filled with concrete, and with wooden piles in 
the center of the concrete. For lack of information on wire saws, the 
Navy evaluated the likely far-field values for the potential zones 
based on the 84-inch caissons (Table 34 in the Compendium), which had 
more data at multiple distances. The Navy ``felt that this was a valid 
approach based on the similarity of the average noise data at 40 m 
(132.5 dB for 66-inch caisson, 134.8 for the 84-inch caisson). Per 
Table 34, using the average dB values at distance, the data shows a 
drop below 129.6 dB RMS at 200 m, but a rise again at 283 m. If you 
plot the regression curve based on the average 84-inch data, we cross 
the ambient threshold at app[roximately] 350 m . . . Because the data 
at far-field distances was variable, we chose a monitoring zone (350 m) 
that was based on the available real-time data. . . . Our assumption is 
that, if a wire saw were

[[Page 48993]]

to be used on the concrete piles, the noise levels would be lower than 
either the 66- or 84-inch caisson.'' The Navy estimated the Level B 
harassment isopleth for this source at 350 m, smaller than the 
Practical Spreading Loss model prediction of 575 m. Given the 
uncertainty discussed above, we used the 575 m distance for the Level B 
harassment isopleth.

Marine Mammal Occurrence, Take Calculation, and Take Estimation

    In this section, we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. Here we describe how the information provided above is 
brought together to produce a quantitative take estimate.
    We examined two approaches towards estimating the Level B take for 
the requested six marine mammal species within the project area at 
Naval Base Point Loma. The first approach was using our standard 
approach of using species density multiplied by isopleth size. The 
second approach utilized daily sightings from monitoring reports 
produced from past Navy projects at Naval Base Point Loma (NAVFAC SW, 
2015a; NACFAC SW, 2017; NAVFAC SW, 2018).
    Density estimates for any specific area assumes that the species' 
in question are evenly distributed across the entire site, which is 
rarely the case. Using the first approach for this project, we examined 
the use of densities, using an overall density for San Diego Bay, 
within a much smaller and definitive area (specifically Naval Base 
Point Loma). This approach, in combination with the predicted Level B 
harassment isopleths, yielded take estimates that were determined to 
not be conservative enough in nature for these activities and activity 
source levels as compared to the results of the in situ measurements 
included in the Navy's Compendium (NAVFAC SW, 2020) and as discussed 
above. Furthermore, the take estimates produced from this method did 
not appropriately account for group size of all marine mammal species 
as the density estimate was for a much larger area (consisting of a 
primarily offshore environment) and assumed a much larger distribution 
of marine mammals. Therefore, this approach was not utilized and will 
not be discussed further.
    The second approach utilized average daily sightings from the Year 
1-5 monitoring reports from IHAs that were previously issued (NAVFAC 
SW, 2015a; NACFAC SW, 2017; NAVFAC SW, 2018). This information was 
provided by the Navy in Table 6.

                                        Table 6--Monitoring Results From the Navy's Years 1-5 Projects at Naval Base Point Loma in San Diego, California
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                              Year 1 project (10 days;    Year 2 project (100 days; El    Year 3 project (59 days)      Year 4 project (152 days)     Year 5 project (49 days)
                                              potential El Ni[ntilde]o          Ni[ntilde]o year)      -----------------------------------------------------------------------------------------
                                                        year)            ------------------------------
                  Species                  ------------------------------                                                    Average                       Average                       Average
                                                                 Average            Average/   Average   Total    Average/    group    Total    Average/    group    Total    Average/    group
                                             Total    Average/    group    Total      day       group               day       size                day       size                day       size
                                                        day       size                          size
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lions......................    2,229      229.9       2.2    7,507       75.1       1.4      483        8.2       1.3    2,263     * 14.9       1.7      618       12.6       1.3
Harbor seal...............................       25        2.5       1.1      248        2.5       1.0       25        0.4       1.0       88      * 0.6       1.1       28        0.6       1.0
Bottlenose dolphins.......................       83        8.3       2.4      695        7.0       2.8       25        0.4       1.9       67      * 0.4       2.7       13        0.3       2.2
Common dolphins...........................       19         19       6.3      850      * 8.5  \2\ 42.5      n/a        n/a       n/a      n/a        n/a       n/a      n/a        n/a       n/a
Pacific white-sided dolphins..............      n/a        n/a       n/a       27      * 0.3       3.9      n/a        n/a       n/a      n/a        n/a       n/a      n/a        n/a       n/a
Northern elephant seals...................      n/a        n/a       n/a    (\1\)      (\1\)     (\1\)      n/a        n/a       n/a      n/a        n/a       n/a      n/a        n/a       n/a
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* These estimates were chosen for the second method in which to estimate take of marine mammals for this action.
\1\ Same individuals was observed hauled out on a beach twice.
\2\ This includes four sightings of groups of 100+ animals outside of San Diego Bay. When these observations are eliminated, the average group size is 6.75 animals observed inside of San Diego
  Bay.

    The Year 1 and 2 monitoring reports demonstrated marine mammal 
estimates during a potential and known El Ni[ntilde]o year, 
respectively. Because of this, these values were likely not 
representative of the typical conditions around Naval Base Point Loma 
and were not preferred.
    California sea lions, harbor seals, and bottlenose dolphins were 
recorded during all other years. Within these, Year 4 was considered 
the most conservative as these activities consisted of the longest 
duration (152 days) with the highest number of sightings for these 
species. Therefore, for these species we used the Year 4 average daily 
values.
    Pacific white-sided dolphins were only recorded during Year 2. 
While these estimates are likely not fully representative of the 
typical distributions of Pacific white-sided dolphins around San Diego 
Bay, they will serve as the basis for our conservative take estimates 
for this species. Common dolphins were observed in Years 1 and 2; 
however, the length of the project period in Year 2 (100 days) was 
considered more representative than the Year 1 project (10 days). 
Therefore, the values from the Year 2 estimates were used for common 
dolphins. A single Northern elephant seal was only recorded to have 
hauled out on a beach twice during all Year 1-5 work. Due to this, no 
average daily estimates were present for analysis; however, some 
discretionary take is authorized in the event Northern elephant seals 
are present during this action.
    For all species (excluding Northern elephant seals), these daily 
sightings were extrapolated over the number of days of pile removal 
activities (84).
    This second approach yielded larger and more conservative Level B 
take estimates, but more realistic for particular species occurrence 
and group size given the data was previously collected at the location 
of this project for similar or the same species during past projects. 
Here we describe how the information provided above is brought together 
to produce a quantitative take estimate.
    By following this daily occurrence-based approach using past 
sightings at Naval Base Point Loma, we will expect that 15 California 
sea lions, 1 harbor seal, 9 common dolphins, 1 Pacific white-sided 
dolphin, and 1 bottlenose dolphin will be sighted per day. 
Multiplication of the above daily occurrences times the number of pile 
removal days planned (84) results in the Level B harassment take of 
1,260 California sea lions, 84 harbor seals, 756 common dolphins, 84 
Pacific white-sided dolphins, and 84 bottlenose dolphins (see Table 7 
for final estimates).
    The Navy has noted that northern elephant seals are very rarely 
seen in this area, with the only true record being of a hauled out and 
distressed juvenile during the Year 2 IHA (NAVFAC SW, 2015a). As a 
precaution that a greater number of northern elephant seal may occur 
around Naval

[[Page 48994]]

Base Point Loma, we authorize seven Level B takes.

                         Table 7--Estimated Take Using the Past Sighting Approach for Each Species and Stock During the Project
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                               Estimated
           Common name              Scientific name           Stock          sightings per   Total Level B take      Data source       Percent of stock
                                                                                  day          requested \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion.............  Zalophus             U.S. Stock.........              15  1,260..............  NAVFAC SW (2017,     0.49.
                                   californianus.                                                                 2018).
Harbor seal.....................  Phoca vitulina.....  California Stock...               1  84.................  NAVFAC SW (2017,     0.27.
                                                                                                                  2018).
Northern elephant seal..........  Mirounga             California Breeding  ..............  \1\ 7..............  NAVFAC SW (2015a)..  0.00.
                                   angustirostris.      Stock.
Common dolphins (Short-beaked,    Delphinus sp.\3\...  California/Oregon/                9  756 (between both    NAVFAC SW (2015a)..  0.08 per SBCD
 long-beaked).                                          Washington Stock;                    species).                                 stock; 0.31 per
                                                        California Stock.                                                              LBCD stock.
Pacific white-sided dolphin.....  Lagenorhynchus       California/Oregon/                1  84.................  NAVFAC SW (2015a)..  0.31.
                                   obliquidens.         Washington--Northe
                                                        rn and Southern
                                                        Stocks.
Bottlenose dolphin..............  Tursiops truncatus.  California Coastal                1  84.................  NAVFAC SW (2017,     18.54.
                                                        Stock.                                                    2018).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Only recently documented near the project occurrence with one distressed individual hauled out on a beach inshore to the south during the second
  year of the previous Fuel Pier IHA (NAVFAC SW, 2015a). A conservative estimate of 2 was assumed with a +5 take buffer added.
\2\ These numbers were derived by multiplying the rounded average daily sightings by 84 days and then summed for the total requested Level B harassment
  take.
\3\ See discussion in the section on Common Dolphins (Short-beaked and Long-beaked) regarding the Society for Marine Mammalogy's Committee on Taxonomy
  decision (Committee on Taxonomy, 2020).

    By using the sighting-based approach, take values are not affected 
by the chosen isopleth sizes from Table 5.
    Given the very small Level A harassment isopleths for all species, 
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, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned), the likelihood of effective implementation (probability 
implemented as planned), and;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    The following mitigation measures are included in the IHA:
     All pile removal activities will occur individually, with 
the exception for the removal of the 14-inch and 16-inch concrete 
piles, which may be removed simultaneously by use of the pile clippers;
     A 20 m (66-ft) shutdown zone will be implemented around 
all pile removal activities (Table 8). If a marine mammal enters the 
shutdown zones, pile removal activities must be delayed or halted;
     Two Protected Species Observers (PSOs) will be employed 
and establish monitoring locations. The Holder must establish 
monitoring locations as described in the Monitoring Plan. For all pile 
removal activities, a minimum of one PSO must be assigned to each 
active pile removal location to monitor the shutdown zones. PSO(s) must 
be able to monitor the entire shutdown zone and the entire Level B 
harassment zone, or out to at least 400 m of the radial distance of the 
larger Level B harassment zones towards the Navigation Channel. In the 
event of concurrent pile removal (i.e., via two pile clippers) at two 
different locations that cannot be appropriately monitored by one PSO, 
the pier or location where the lead PSO is stationed being blocked by a 
refueling vessel or other obstruction, multiple PSOs may be necessary 
to monitor the necessary shutdown and Level B harassment zones;
     If pile removal activities have been halted or delayed due 
to the presence of a species in the shutdown zone, activities may 
commence only after the animal has been visually sighted to have 
voluntarily exited the shutdown zone, or after 15 minutes have passed 
without a re-detection of the animal;
     If the take reaches the authorized limit for an authorized 
species, or if a marine mammal species that is not authorized for this 
project enters the Level B harassment zone, pile removal will cease 
until consultation with NMFS can occur. If in-water pile removal 
activities are occurring when a non-authorized species enters the Level 
B harassment zone, activities must shutdown;
     The placement of the PSOs during all pile removal 
activities will ensure that the entire shutdown zone is visible. Should 
environmental conditions deteriorate such that marine mammals within 
the entire shutdown zone will

[[Page 48995]]

not be visible (e.g., fog, heavy rain), pile removal must be delayed 
until the lead PSO is confident that marine mammals within the shutdown 
could be detected;
     PSOs must record all observations of marine mammals as 
described in the Monitoring Plan, regardless of distance from the pile 
being driven. PSOs shall document any behavioral reactions in concert 
with distance from piles being driven or removed;
     The marine mammal monitoring reports must contain the 
informational elements described in the Monitoring Plan;
     A draft marine mammal monitoring report, and PSO 
datasheets and/or raw sighting data, must be submitted to NMFS within 
90 calendar days after the completion of pile driving activities. If no 
comments are received from NMFS within 30 calendar days, the draft 
report will constitute the final report. If comments are received, a 
final report addressing NMFS comments must be submitted within 30 
calendar days after receipt of comments; and
     In the event that personnel involved in the construction 
activities discover an injured or dead marine mammal, the IHA-holder 
must immediately cease the specified activities and report the incident 
to the Office of Protected Resources (OPR) 
([email protected] and [email protected]), NMFS and 
to the West Coast Regional Stranding Coordinator as soon as feasible.

                                     Table 8--Shutdown and Harassment Zones
                                                   [(Meters)]
----------------------------------------------------------------------------------------------------------------
                                                                                    Harassment       Shutdown
               Pile information                          Removal method                zone           zone\1\
----------------------------------------------------------------------------------------------------------------
13-inch polycarbonate pile....................  One pile clipper................             423              20
14-inch, 16-inch concrete piles...............  One pile clipper................             250
14-inch, 16-inch concrete pile................  Two pile clippers...............             250
14-inch, 16-inch concrete pile................  Underwater chainsaw.............             229
14-inch, 16-inch concrete pile................  Diamond wire saw................             575
14-inch, 16-inch concrete pile................  Vibratory hammer................             311
----------------------------------------------------------------------------------------------------------------
\1\ The shutdown zone is the same for all mid-frequency cetaceans, phocid pinnipeds, and otariid pinnipeds.

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 in the 
action area. 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 action; 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).
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
submitted Monitoring Plan and the Mitigation and the Monitoring and 
Reporting sections of the IHA. Marine mammal monitoring during pile 
driving and removal must be conducted by NMFS-approved PSOs in a manner 
consistent with the following:
     Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods must be used;
     At least one PSO must have prior experience performing the 
duties of a PSO during construction activity pursuant to a NMFS-issued 
incidental take authorization.
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience;
     Where a team of two or more PSOs are required, one PSO 
will be designated as the ``Command'', or lead PSO, and will coordinate 
all monitoring efforts. The lead PSO must have prior experience 
performing the duties of an observer;
     In the event of concurrent pile removal activities, two 
lead PSOs may be designated and will coordinate and communicate all 
monitoring efforts if a single observer cannot observe the two 
concurrent activities. Each position will act independently and both 
will maintain the ability to call for a shutdown. Each lead PSOs will 
communicate to the other of a potential sighting of a marine protected 
species traveling from one location to the other within the appropriate 
shutdown and Level B zones during concurrent pile removal activities.
     The Navy must submit PSO Curriculum Vitae (CV) for 
approval by NMFS prior to the onset of pile driving.
    PSOs must 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

[[Page 48996]]

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.
    Up to two PSOs will be employed. PSO locations will provide an 
unobstructed view of all water within the shutdown zone, and as much of 
the Level A and Level B harassment zones as possible. PSO locations 
have been discussed above. An additional monitoring location is 
described as follows:
    (1) An additional monitoring location on the Fuel Pier trestle or 
on a captained vessel may be utilized for pre-activity monitoring if 
the monitoring zone is beyond the visual range of the lead PSO's 
position. This vessel will start south of the Project area (where 
potential marine mammal occurrence is lowest) before the pile removal 
activity has begun and move north.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after pile removal activities. In addition, observers shall 
record all incidents of marine mammal occurrence, regardless of 
distance from activity and distance from the buffered shutdown zone and 
Level B harassment isopleth, and shall document any behavioral 
reactions in concert with distance from piles being removed.

Hydroacoustic Monitoring and Reporting

    The Navy has indicated in their application that they may perform 
hydroacoustic monitoring on any removal method and sound source that 
was not previously recorded and included in the Compendium of 
Underwater and Airborne Sound Data during Pile Installation and In-
Water Demolition Activities in San Diego Bay, California (NAVFAC SW, 
2020). However, as data from the Compendium (for pile clippers, wire 
saw, and underwater chainsaw) and the City of Seattle Pier 62 project 
(for the vibratory hammer; Greenbusch Group, 2018) are recent, it is 
unlikely that hydroacoustic monitoring will occur during this project.

Reporting

    A draft marine mammal monitoring and acoustic measurement report 
will be submitted to NMFS within 90 calendar days after the completion 
of these activities, or 60 days prior to a requested date or issuance 
of any future IHAs for projects at the same location, whichever comes 
first. The report will include an overall description of work 
completed, a narrative regarding marine mammal sightings, and 
associated PSO data sheets. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring;
     Construction activities occurring during each daily 
observation period, including how many and what type of piles were 
removed and by what method (i.e., vibratory and if other removal 
methods were used);
     Weather parameters and water conditions during each 
monitoring period (e.g., wind speed, percent cover, visibility, sea 
state);
     The number of marine mammals observed, by species, 
relative to the pile location and if pile removal was occurring at time 
of sighting;
     Age and sex class, if possible, of all marine mammals 
observed;
     PSO locations during marine mammal monitoring;
     Distances and bearings of each marine mammal observed to 
the pile being driven or removed for each sighting (if pile removal was 
occurring at time of sighting);
     Description of any marine mammal behavior patterns during 
observation, including direction of travel and estimated time spent 
within the Level A and Level B harassment zones while the source was 
active;
     Number of individuals of each species (differentiated by 
month as appropriate) detected within the monitoring zone, and 
estimates of number of marine mammals taken, by species (a correction 
factor may be applied to total take numbers, as appropriate);
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any;
     Description of attempts to distinguish between the number 
of individual animals taken and the number of incidences of take, such 
as ability to track groups or individuals; and
     Submit all PSO datasheets and/or raw sighting data (in a 
separate file from the Final Report referenced immediately above).
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, and the lead PSO determines 
that the cause of the injury or death is unknown and the death is 
relatively recent (i.e., in less than a moderate state of 
decomposition), the lead PSO will report to the Navy POC. The Navy POC 
shall then report the incident to the Office of Protected Resources 
(OPR), NMFS and to the regional stranding coordinator as soon as 
feasible. If the death or injury was clearly caused by the specified 
activity, the Navy must 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 IHA. The IHA-holder must not resume 
their activities until notified by NMFS. The report must include the 
following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     Description of marine mammals observation in the 24-hours 
preceding the incident;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact

[[Page 48997]]

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 responses 
(e.g., intensity, duration), the context of any responses (e.g., 
critical reproductive time or location, migration), 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's 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 environmental 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).
    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 removal activities have the potential to disturb or displace 
marine mammals. Specifically, the project activities may result in 
take, in the form of Level B harassment only from underwater sounds 
generated from pile cutting and removal activities. Takes could occur 
if individuals are present in the ensonified zones when these 
activities are underway. The potential for harassment is minimized 
through the construction method and the implementation of the planned 
mitigation measures (see Mitigation and the Monitoring and Reporting 
sections).
    Take would occur within a limited, confined area (mouth of San 
Diego Bay) of each stock's range. Level B harassment would 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, except for bottlenose dolphins, when 
compared to stock abundance.
    Behavioral responses of marine mammals to pile removal at the 
project site, if any, are expected to be mild and temporary. Marine 
mammals within the Level B harassment zone may not show any visual cues 
they are disturbed by activities (as noted during modification to the 
Kodiak Ferry Dock (ABR, 2016; see 80 FR 60636, October 7, 2015)) or 
could become alert, avoid the area, leave the area, or display other 
mild responses that are not observable such as changes in vocalization 
patterns. Given the short duration of noise-generating activities per 
day and that pile removal would occur across six months, any harassment 
would be temporary. There are no areas or times of known biological 
importance for any of the affected species.
    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 the species or stock through 
effects on annual rates of recruitment or survival:
     No mortality or Level A harassment is anticipated or 
authorized;
     No biologically important areas have been identified with 
the project area;
     The Navy is required to implement mitigation measures to 
minimize impacts, such as PSO observation and a shutdown zone of 20 m 
(66 ft);
     For all species, San Diego Bay is a very small and 
peripheral part of their range; 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 
activity would have a negligible impact on all affected marine mammal 
species or stocks.

Small Numbers

    As noted above, 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 proposes to authorize is below one third of 
the estimated stock abundances for all six species (Table 7). For most 
requested species, the take of individuals is less than 1 percent of 
the abundance of the affected stock (with exception for common 
bottlenose dolphins at 18.54 percent). This is likely a conservative 
estimate because it assumes all take are of different individual 
animals, which is likely not the case. Some individuals may return 
multiple times in a day, but PSOs would count them as separate takes if 
they cannot be individually identified.
    Based on the analysis contained herein of the Navy's activity 
(including the Mitigation and the Monitoring and Reporting sections) 
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 (ESA)

    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

[[Page 48998]]

consultation under section 7 of the ESA is not required for this 
action.

National Environmental Policy Act (NEPA)

    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 will 
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 Navy for the potential harassment of 
small numbers of six marine mammal species incidental to the pile 
removal activities at Naval Base Point Loma in San Diego Bay, 
California from January 15, 2022 through January 14, 2023, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated.

    Dated: August 27, 2021.
Catherine Marzin,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2021-18877 Filed 8-31-21; 8:45 am]
BILLING CODE 3510-22-P