Notice2021-18877
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Fuel Pier Inboard Pile Removal Project in San Diego, California
Primary source
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Published
September 1, 2021
Effective
January 15, 2022
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an 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.
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[Federal Register Volume 86, Number 167 (Wednesday, September 1, 2021)]
[Notices]
[Pages 48986-48998]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[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: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-fuel-pier-removal-naval-base-san-diego-california">https://www.fisheries.noaa.gov/action/incidental-take-authorization-us-navy-fuel-pier-removal-naval-base-san-diego-california</a>. 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 (<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities">https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities</a>).
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; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
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; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>). 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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</a>).
[[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: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a> 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 (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) 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
<a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 2--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 <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-naval-base-san-diego-pier-6-replacement-project-san-diego">https://www.fisheries.noaa.gov/action/incidental-take-authorization-naval-base-san-diego-pier-6-replacement-project-san-diego</a>), 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:
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> 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;
<bullet> The marine mammal monitoring reports must contain the
informational elements described in the Monitoring Plan;
<bullet> 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
<bullet> 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)
(<a href="/cdn-cgi/l/email-protection#6e3e3c40273a3e40230100071a011c0700093c0b1e011c1a1d2e00010f0f40090118"><span class="__cf_email__" data-cfemail="a4f4f68aedf0f48ae9cbcacdd0cbd6cdcac3f6c1d4cbd6d0d7e4cacbc5c58ac3cbd2">[email protected]</span></a> and <a href="/cdn-cgi/l/email-protection#cf869b9fe19fa0bba3a0aca48fa1a0aeaee1a8a0b9"><span class="__cf_email__" data-cfemail="bff6ebef91efd0cbd3d0dcd4ffd1d0dede91d8d0c9">[email protected]</span></a>), 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:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density).
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors.
<bullet> How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks.
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat).
<bullet> 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:
<bullet> Independent PSOs (i.e., not construction personnel) who
have no other assigned tasks during monitoring periods must be used;
<bullet> At least one PSO must have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
incidental take authorization.
<bullet> Other PSOs may substitute education (degree in biological
science or related field) or training for experience;
<bullet> 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;
<bullet> 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.
<bullet> 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:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction
[[Page 48996]]
operation to provide for personal safety during observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
<bullet> Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
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:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> 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);
<bullet> Weather parameters and water conditions during each
monitoring period (e.g., wind speed, percent cover, visibility, sea
state);
<bullet> The number of marine mammals observed, by species,
relative to the pile location and if pile removal was occurring at time
of sighting;
<bullet> Age and sex class, if possible, of all marine mammals
observed;
<bullet> PSO locations during marine mammal monitoring;
<bullet> 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);
<bullet> 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;
<bullet> 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);
<bullet> 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;
<bullet> 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
<bullet> 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:
<bullet> Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
<bullet> Species identification (if known) or description of the
animal(s) involved;
<bullet> Condition of the animal(s) (including carcass condition if
the animal is dead);
<bullet> Observed behaviors of the animal(s), if alive;
<bullet> Description of marine mammals observation in the 24-hours
preceding the incident;
<bullet> If available, photographs or video footage of the
animal(s); and
<bullet> 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:
<bullet> No mortality or Level A harassment is anticipated or
authorized;
<bullet> No biologically important areas have been identified with
the project area;
<bullet> The Navy is required to implement mitigation measures to
minimize impacts, such as PSO observation and a shutdown zone of 20 m
(66 ft);
<bullet> For all species, San Diego Bay is a very small and
peripheral part of their range; and
<bullet> 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
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