[Federal Register Volume 88, Number 21 (Wednesday, February 1, 2023)]
[Notices]
[Pages 6703-6714]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-02107]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XC585]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Replacement of Pier 302 at Naval
Base Point Loma, San Diego, California
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of an incidental harassment authorization.
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SUMMARY: In accordance with the regulations implementing the Marine
Mammal Protection Act (MMPA) as amended, notification is hereby given
that NMFS has issued an incidental harassment authorization (IHA) to
the U.S. Navy to incidentally harass, by Level B harassment only,
marine mammals during construction activities associated with a Pier
302 Replacement project at Naval Base Point Loma, San Diego,
California.
DATES: This authorization is effective from October 1, 2023 through
September 30, 2024.
FOR FURTHER INFORMATION CONTACT: Jessica Taylor, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems
accessing these documents, please call the contact listed above.
SUPPLEMENTARY INFORMATION:
Background
The MMPA prohibits the ``take'' of marine mammals, with certain
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to
allow, upon request, the incidental, but not intentional, taking of
small numbers of marine mammals by U.S. citizens who engage in a
specified activity (other than commercial fishing) within a specified
geographical region if certain findings are made and either regulations
are proposed or, if the taking is limited to harassment, a notice of a
proposed IHA is provided to the public for review.
Authorization for incidental takings shall be granted if NMFS finds
that the taking will have a negligible impact on the species or
stock(s) and will not have an unmitigable adverse impact on the
availability of the species or stock(s) for taking for subsistence uses
(where relevant). Further, NMFS must prescribe the permissible methods
of taking and other ``means of effecting the least practicable adverse
impact'' on the affected species or stocks and their habitat, paying
particular attention to rookeries, mating grounds, and areas of similar
significance, and on the availability of the species or stocks for
taking for certain subsistence uses (referred to in shorthand as
``mitigation''); and requirements pertaining to the mitigation,
monitoring and reporting of the takings are set forth. The definitions
of all applicable MMPA statutory terms cited above are included in the
relevant sections below.
Summary of Request
On July 27, 2022, NMFS received a request from the U.S. Navy for an
IHA to take marine mammals incidental to construction activities
associated with replacing Pier 302 at Naval Base Point Loma (NBPL), San
Diego, CA. Following NMFS' review of the application, the U.S. Navy
submitted a revised version on September 22, 2022. The application was
deemed adequate and complete on October 27, 2022. The U.S. Navy's
request is for take of six species of marine mammals by Level B
harassment only. Neither the U.S. Navy nor NMFS expect serious injury
or mortality to result from this activity, therefore, an IHA is
appropriate. There were no changes from the proposed to the final IHA.
NMFS has previously issued IHAs to the U.S. Navy for similar work
over the past 9 years at NBPL in San Diego Bay (Bay), including IHAs
issued effective from September 1, 2013, through August 31, 2014 (78 FR
44539, July 24, 2013; Year 1 Project), October 8, 2014 through October
7, 2015 (79 FR 65378, November 4, 2014; Year 2 Project), October 8,
2015 through October 7, 2016 (80 FR 62032, October 15, 2015; Year 3
Project), October 8, 2016 through October 7, 2017 (81 FR 66628,
[[Page 6704]]
September 28, 2016; Year 4 Project), October 8, 2017 through October 7,
2018 (82 FR 45811, October 2, 2017; Year 5 Project), September 15, 2020
through September 14, 2021 (85 FR 33129, June 1, 2020; Floating Dry
Dock Project), October 1, 2021 through September 30, 2022 (86 FR 7993,
February 3, 2021; Pier 6 Replacement Project), and January 15, 2022
through January 14, 2023 (86 FR 48986, September 1, 2021; Fuel Pier
Inboard Pile Removal Project). The U.S. Navy complied with all the
requirements (e.g., mitigation, monitoring, and reporting) of the
previous IHA and information regarding their monitoring results
specific to NBPL may be found in the Estimated Take section.
Description of Activity
The U.S. Navy plans to replace Pier 302 at the Naval Information
Warfare Center (NIWC) Pacific Bayside Complex on NBPL. Pier 302 houses
the U.S. Navy marine mammal pens and support vessels. As part of the
project, the U.S. Navy will use vibratory extraction to remove the
existing components of marine mammal pens, and impact and vibratory
hammers to install new pens. The purpose of the project is to provide
the U.S. Navy's marine mammal program with adequate facilities to house
its marine mammals and provide a safe working environment for personnel
to support the U.S. Navy's overall mission to maintain, train, and
equip combat ready Naval forces.
The Navy's activity includes impact and vibratory pile driving,
which may result in the incidental take of marine mammals, by Level B
harassment only. No Level A harassment is anticipated to occur, and
none is authorized. Due to mitigation measures, only takes by Level B
harassment are requested. NBPL is located along the mouth and northern
edge of San Diego Bay, CA. The project covers an area of 9,061 feet
(ft.)\2\ (842 meters (m)\2\). Construction activities will occur over
32 days within a 1 year window from October 1, 2023 to September 30,
2024. The Navy states that it will conduct work only in daylight hours.
A detailed description of the planned construction project is provided
in the Federal Register notice for the proposed IHA (87 FR 68442,
November 15, 2022). Since that time, no changes have been made to the
planned activities. Therefore, a detailed description is not provided
here. Please refer to that Federal Register notice for the description
of the specific activity. Mitigation, monitoring, and reporting
measures are described in detail later in this document (please see
Mitigation and Monitoring and Reporting).
Comments and Responses
A notice of NMFS' proposal to issue an IHA to the U.S. Navy was
published in the Federal Register on November 15, 2022 (87 FR 68442).
That notice described, in detail, the U.S. Navy's activities, the
marine mammal species that may be affected by the activities, and the
anticipated effects on marine mammals. During the 30-day public comment
period, no public comments were received.
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history of the potentially affected species. NMFS
fully considered all of this information, and we refer the reader to
these descriptions, incorporated here by reference, instead of
reprinting the information. Additional information regarding population
trends and threats may be found in NMFS' Stock Assessment Reports
(SARs; www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these
species (e.g., physical and behavioral descriptions) may be found on
NMFS' website (https://www.fisheries.noaa.gov/find-species).
Table 1 lists all species or stocks for which take is expected and
authorized for this activity, and summarizes information related to the
population or stock, including regulatory status under the MMPA and
Endangered Species Act (ESA) and potential biological removal (PBR),
where known. PBR is defined by the MMPA as the maximum number of
animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its
optimum sustainable population (as described in NMFS' SARs). While no
serious injury or mortality is expected to occur, PBR and annual
serious injury and mortality from anthropogenic sources are included
here as gross indicators of the status of the species or stocks and
other threats.
There are six marine mammal species that are potentially expected
to be present during all or a portion of the in-water work associated
with this project in San Diego Bay, including the California sea lion
(Zalophus californianus), the northern elephant seal (Mirounga
angustirostris), the harbor seal (Phoca vitulina), the bottlenose
dolphin (Tursiops truncatus), the Pacific white-sided dolphin
(Lagenorhynchus obliquidens), and the common dolphin (Delphinus
delphis). The Committee on Taxonomy (https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/)
recently determined both the long-beaked and short-beaked common
dolphin belong in the same species and we adopt this taxonomy. However,
the SARs still describe the two as separate stocks, and that stock
information is presented in Table 1. Marine mammal abundance estimates
presented in this document represent the total number of individuals
that make up a given stock or the total number estimated within a
particular study or survey area. NMFS' stock abundance estimates. For
some species, this geographic area may extend beyond U.S. waters. All
stocks managed under the MMPA in this region are assessed in NMFS' U.S.
Pacific 2021 SARs. All values presented in Table 2 are the most recent
available at the time of publication and are available online at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments).
Table 1--Marine Mammal Species \4\ Likely Impacted by the Specified Activities
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ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
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Order Artiodactyla--Infraorder Cetacea-- Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Bottlenose dolphin.............. Tursiops truncatus..... California Coastal..... -, -, N 453 (0.06, 346, 2011). 2.7 >=2.0
Short-beaked common dolphin..... Delphinus delphis California/Oregon/ -, -, N 1,056,308 (0.21, 8889 >=30.5
delphis. Washington. 888,971, 2018).
[[Page 6705]]
Long-beaked common dolphin...... Delphinus delphis California............. -, -, N 83,379 (0.216, 69,636, 668 >=29.7
capensis. 2018).
Pacific white-sided dolphin..... Lagenorhynchus California/Oregon/ -, -, N 34,999 (0.222, 29,090, 279 7
obliquidens. Washington. 2018).
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Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
California sea lion............. Zalophus californianus. U.S.................... -, -, N 257,606 (N/A,233,515, 14011 >320
2014).
Family Phocidae (earless seals):
Harbor seal..................... Phoca vitulina......... California............. -, -, N 30,968 (N/A, 27,348, 1641 43
2012).
Northern elephant seal.......... Mirounga angustirostris California breeding.... -, -, N 187,386 (N/A, 85,369, 5122 13.7
2013).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments/ assessments/. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
commercial fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV
associated with estimated mortality due to commercial fisheries is presented in some cases.
\4\ Information on the classification of marine mammal species can be found on the web page for The Society for Marine Mammalogy's Committee on Taxonomy
(https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/; Committee on Taxonomy (2022)).
As indicated above, all six species (with seven managed stocks) in
Table 1 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. While gray whales,
Risso's dolphins, and Steller sea lions have been sighted around
California coastal waters in the past, these species' general spatial
occurrence is such that take is not expected to occur as they typically
occur more offshore. Therefore, the Navy did not request, and NMFS is
not authorizing take of these species.
A detailed description of the species likely to be affected by the
Naval Base Point Loma Pier 302 Replacement Project, including brief
introductions to the species and relevant stocks as well as available
information regarding population trends and threats, and information
regarding local occurrence, were provided in the Federal Register
notice for the proposed IHA (87 FR 68442, November 15, 2022); since
that time, we are not aware of any changes in the status of these
species and stocks; therefore, detailed descriptions are not provided
here. Please refer to that Federal Register notice for these
descriptions. Please also refer to the NMFS website (https://www.fisheries.noaa.gov/find-species) for generalized species accounts.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al.
(2007, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). Note that no direct measurements of
hearing ability have been successfully completed for mysticetes (i.e.,
low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 2.
Table 2--Marine Mammal Hearing Groups
[NMFS, 2018]
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Hearing group Generalized hearing range *
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Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
Cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
[[Page 6706]]
Otariid pinnipeds (OW) (underwater) 60 Hz to 39 kHz.
(sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
composite (i.e., all species within the group), where individual
species' hearing ranges are typically not as broad. Generalized
hearing range chosen based on ~65 dB threshold from normalized
composite audiogram, with the exception for lower limits for LF
cetaceans (Southall et al., 2007) and PW pinniped (approximation).
The pinniped functional hearing group was modified from Southall et
al. (2007) on the basis of data indicating that phocid species have
consistently demonstrated an extended frequency range of hearing
compared to otariids, especially in the higher frequency range
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt,
2013).
For more detail concerning these groups and associated frequency
ranges, please see NMFS (2018) for a review of available information.
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
The effects of underwater noise from the Navy's pile driving
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of the
proposed IHA (87 FR 68442, November 15, 2022) included a discussion of
the effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from the Navy's pile driving activities on
marine mammals and their habitat. That information and analysis is
incorporated by reference into this final IHA determination and is not
repeated here; please refer to the notice of the proposed IHA (87 FR
68442, November 15, 2022).
Estimated Take
This section provides an estimate of the number of incidental takes
authorized through this IHA, which has informed both NMFS'
consideration of ``small numbers,'' and the negligible impact
determinations.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes will be by Level B harassment only, in the form of
disruption of behavioral patterns for individual marine mammals
resulting from exposure to the acoustic sources. Based on the nature of
the activity and the anticipated effectiveness of the mitigation
measures (i.e., vibratory or impact pile driving and removal) discussed
in detail below in the Mitigation section. Level A harassment is
neither anticipated nor authorized.
As described previously, no serious injury or mortality is
anticipated or authorized for this activity. Below we describe how the
authorized take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic thresholds above which NMFS believes the best
available science indicates marine mammals will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and, (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the authorized take estimates.
Acoustic Thresholds
NMFS recommends the use of acoustic thresholds that identify the
received level of underwater sound above which exposed marine mammals
would be reasonably expected to be behaviorally harassed (equated to
Level B harassment) or to incur permanent threshold shift (PTS) of some
degree (equated to Level A harassment).
Level B Harassment--Though significantly driven by received level,
the onset of behavioral disturbance from anthropogenic noise exposure
is also informed to varying degrees by other factors related to the
source or exposure context (e.g., frequency, predictability, duty
cycle, duration of the exposure, signal-to-noise ratio, distance to the
source), the environment (e.g., bathymetry, other noises in the area,
predators in the area), and the receiving animals (hearing, motivation,
experience, demography, life stage, depth) and can be difficult to
predict (e.g., Southall et al., 2007, 2021; Ellison et al., 2012).
Based on what the available science indicates and the practical need to
use a threshold based on a metric that is both predictable and
measurable for most activities, NMFS typically uses a generalized
acoustic threshold based on received level to estimate the onset of
behavioral harassment. NMFS generally predicts that marine mammals are
likely to be behaviorally harassed in a manner considered to be Level B
harassment when exposed to underwater anthropogenic noise above root-
mean-squared pressure received levels (RMS SPL) of 120 dB (referenced
to 1 micropascal (re 1 [mu]Pa)) for continuous (e.g., vibratory pile-
driving, drilling) and above RMS SPL 160 dB re 1 [mu]Pa for non-
explosive impulsive (e.g., seismic airguns) or intermittent (e.g.,
scientific sonar) sources. Generally speaking, Level B harassment take
estimates based on these behavioral harassment thresholds are expected
to include any likely takes by temporary threshold shift (TTS) as, in
most cases, the likelihood of TTS occurs at distances from the source
less than those at which behavioral harassment is likely. TTS of a
sufficient degree can manifest as behavioral harassment, as reduced
hearing sensitivity and the potential reduced opportunities to detect
important signals (conspecific communication, predators, prey) may
result in changes in behavior patterns that would not otherwise occur.
The Navy's construction activities include the use of continuous
(vibratory pile-driving) and impulsive (impact pile-driving) sources,
and therefore the RMS SPL threshold of 160 dB re 1 [mu]Pa is applicable
for impulsive noise. For continuous noise, the RMS SPL
[[Page 6707]]
threshold of 129.6 dB re 1 [mu]Pa is applicable as a de facto
harassment threshold, based upon measured noise data for San Diego Bay
as referenced in the Description of Activity section in the notice for
the proposed IHA (87 FR 68442, November 15, 2022).
Level A Harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different marine mammal groups
(based on hearing sensitivity) as a result of exposure to noise from
two different types of sources (impulsive or non-impulsive). The Navy's
activity includes the use of impulsive (impact hammer) and non-
impulsive (vibratory hammer) sources.
These thresholds are provided in the table below. The references,
analysis, and methodology used in the development of the thresholds are
described in NMFS' 2018 Technical Guidance, which may be accessed at:
www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
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PTS onset thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
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Low-Frequency (LF) Cetaceans........... Cell 1: L0-pk,flat: 219 Cell 2: LE,LF,24h: 199 dB.
dB; LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: L0-pk,flat: 230 Cell 4: LE,MF,24h: 198 dB.
dB; LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: L0-pk,flat: 202 Cell 6: LE,HF,24h: 173 dB.
dB; LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: L0-pk.flat: 218 Cell 8: LE,PW,24h: 201 dB.
dB; LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: L0-pk,flat: 232 Cell 10: LE,OW,24h: 219 dB.
dB; LE,OW,24h: 203 dB.
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* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS
onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
associated with impulsive sounds, these thresholds are recommended for consideration.
Note: Peak sound pressure level (L0-pk) has a reference value of 1 [mu]Pa, and weighted cumulative sound
exposure level (LE,) has a reference value of 1[mu]Pa\2\s. In this Table, thresholds are abbreviated to be
more reflective of International Organization for Standardization standards (ISO, 2017). The subscript
``flat'' is being included to indicate peak sound pressure are flat weighted or unweighted within the
generalized hearing range of marine mammals (i.e., 7 Hz to 160 kHz). The subscript associated with cumulative
sound exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF,
and HF cetaceans, and PW and OW pinnipeds) and that the recommended accumulation period is 24 hours. The
weighted cumulative sound exposure level thresholds could be exceeded in a multitude of ways (i.e., varying
exposure levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate
the conditions under which these thresholds will be exceeded.
Ensonified Area
Here, we describe operational and environmental parameters of the
activity that are used in estimating the area ensonified above the
acoustic thresholds, including source levels and transmission loss
coefficient.
The sound field in the project area is the existing background
noise plus additional construction noise from the project. Marine
mammals are expected to be affected by sound generated by the primary
components of the project (i.e., impact and vibratory pile driving).
In order to calculate distances to the Level A harassment and Level
B harassment thresholds for the methods and piles being used in this
project, the Navy used acoustic monitoring data from various similar
locations to develop source levels for the different pile types, sizes,
and methods planned for use (Table 4).
Table 4--Source Levels for Removal and Installation Activities
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Peak sound
pressure (dB Mean maximum SEL (dB re 1
Method Pile size/type re 1 [mu]Pa) RMS SPL (dB re [mu]Pa2 sec) \1\ Source
\1\ 1 [mu]Pa) \1\
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Pile Removal Activities
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Vibratory Extraction............... 18'' Octagonal .............. \3\ 162 ................... NAVFAC SW, 2022.
Concrete \2\.
18'' Steel Pipe...... .............. \4\ 156 ................... Denes et al., 2016.
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Pile Installation Activities
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Impact Pile Driving................ 24'' Octagonal 188 176 166 Caltrans, 2020.
Concrete.
14'' Square Concrete. 183 166 154 Caltrans, 2020.
Vibratory Hammer................... 6'' Round Steel \5\.. 171 155 155 Illingworth and Rodkin, 2007.
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\1\ As measured, or calculated, at 10 m (33 ft).
\2\ In the absence of information on vibratory extraction of 18-inch octagonal concrete piles, source data from 20-inch concrete square piles NAVFAC SW
(2022) was used as a proxy source level.
\3\ The maximum mean calculated source value for 20-inch square concrete piles (NAVFAC SW, 2022) was 162 dB RMS based on unpublished data from the Pier
6 Replacement Project.
\4\ Table 20 in Denes et al. (2016) records a value of 152.4 dB RMS at 17 m (56 ft) for vibratory extraction. This data point, and a transmission loss
of 15LogR, was used to back-calculate a value of 155.9 dB RMS at 10 m (33 ft) (rounded to 156 dB RMS).
\5\ In the absence of information on vibratory installation of 6-inch round steel piles, source data from 12-inch round steel piles (Illingworth &
Rodkin, 2017) was used as a proxy source level.
Abbreviations: [mu]Pa = microPascal; dB = decibel; RMS = root mean square; SPL = sound pressure level; m= meters; SEL = sound exposure level.
[[Page 6708]]
Level B Harassment Zones
Transmission loss (TL) is the decrease in acoustic intensity as an
acoustic pressure wave propagates out from a source. TL parameters vary
with frequency, temperature, sea conditions, current, source and
receiver depth, water depth, water chemistry, and bottom composition
and topography. The general formula for underwater TL is:
TL = B * Log10 (R1/R2),
where
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement
The recommended TL coefficient for most nearshore environments is
the practical spreading value of 15. This value results in an expected
propagation environment that would lie between spherical and
cylindrical spreading loss conditions, which is the most appropriate
assumption for the Navy's activities. The Level B harassment zones and
areas of zones of influence (ZOIs) for the Navy's activities are shown
in Table 5.
Table 5--Distance to Level B Harassment Thresholds and ZOI Areas
----------------------------------------------------------------------------------------------------------------
Projected radial distance to
Maximum RMS Level B harassment thresholds
Method Pile size/type SPL (dB re 1 and ensonified area \1\ \2\
[mu]Pa) \1\ -------------------------------
Distance m Area km\2\
----------------------------------------------------------------------------------------------------------------
Pile Removal Activities
----------------------------------------------------------------------------------------------------------------
Vibratory Extraction.................. 18'' Octagonal Concrete. 162 1,445 3.13
18'' Steel Pipe......... 156 575 0.68
----------------------------------------------------------------------------------------------------------------
Pile Installation Activities
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving \3\............... 24'' Octagonal Concrete. 176 117 0.041
Impact Pile Driving................... 14'' Square Concrete.... 166 25 <0.01
Vibratory Hammer...................... 6'' Round Steel......... 155 494 0.45
----------------------------------------------------------------------------------------------------------------
\1\ The Level B ZOIs for continuous pile removal and installation activities are based on the distance for noise
to decay to ambient levels (129.6 dB re 1[mu]Pa), while 160 dB was used for impulsive sound.
\2\ Assumes Practical Spreading Loss.
\3\ With or without High[hyphen]pressure Water Jetting.
Abbreviations: dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, km\2\ = square kilometers, m
= meters, ft = feet, RMS = root mean square, ZOI = Zone of Influence.
Level A Harassment Zones
The ensonified area associated with Level A harassment is more
technically challenging to predict due to the need to account for a
duration component. Therefore, NMFS developed an optional User
Spreadsheet tool to accompany the Technical Guidance that can be used
to relatively simply predict an isopleth distance for use in
conjunction with marine mammal density or occurrence to help predict
potential takes. We note that because of some of the assumptions
included in the methods underlying this optional tool, we anticipate
that the resulting isopleth estimates are typically going to be
overestimates of some degree, which may result in an overestimate of
potential take by Level A harassment. However, this optional tool
offers the best way to estimate isopleth distances when more
sophisticated modeling methods are not available or practical. For
stationary sources, such as pile installation or removal, the optional
User Spreadsheet tool predicts the distance at which, if a marine
mammal remained at that distance for the duration of the activity, it
would be expected to incur PTS. The isopleths generated by the User
Spreadsheet used the same TL coefficient as the Level B harassment zone
calculations (i.e., the practical spreading value of 15). Inputs used
in the User Spreadsheet (e.g., number of piles per day, duration and/or
strikes per pile) are presented in Table 1 of the notice for the
proposed IHA (87 FR 68442, November 15, 2022). The maximum RMS SPL/SEL
SPL and resulting isopleths are reported below in Table 6. The maximum
RMS SPL value was used to calculate Level A harassment isopleths for
vibratory pile driving and extraction activities, while the single
strike SEL SPL value was used to calculate Level A isopleths for impact
pile driving activities.
Table 6--Distances to Level A Harassment Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Single strike Project distances to Level A
Maximum RMS SEL (dB re 1 Duration (hrs/ thresholds (m)
Method Pile size/type SPL (dB re 1 [mu]Pa\2\ sec) day) --------------------------------------
[mu]Pa) \1\ \1\ MF PW OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile Removal Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Vibratory Extraction.................. 18'' Octagonal Concrete 162 N/A 1.25 0.8 5.6 0.4
\2\.
18'' Steel Pipe.......... \2\ 156 N/A 0.25 0.1 0.8 0.1
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Pile Driving................... 24'' Octagonal Concrete.. 176 166 1.33 4.1 \3\ 62.4 4.5
14'' Square Concrete..... 166 154 0.25 0.2 2.5 0.2
Vibratory Hammer...................... 6'' Round Steel.......... 155 155 0.07 0.0 0.3 0.0
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ As measured at 10 m (33 ft.).
[[Page 6709]]
\2\ Table 20 in Denes et al. (2016) records a value of 152.4 dB RMS at 17 m (56 ft.) for vibratory extraction. This data point, and a transmission loss
of 15LogR, was used to back[hyphen]calculate a value of 156 dB RMS at 10 m (33 ft.).
\3\ Value is greater than the standard shutdown zone of 20 m (see Mitigation section) and will be monitored as shutdown zone to ensure no Level A takes
of harbor seals or northern elephant seals occur during impact pile driving of 24-inch octagonal concrete piles.
Abbreviations: RMS = root mean square, dB re 1 [mu]Pa = decibels referenced to a pressure of 1 microPascal, m = meters, ft = feet, SEL = sound exposure
level, MF = mid-frequency cetaceans, PW = phocid pinnipeds, OW = otariid pinnipeds.
Marine Mammal Occurrence
In this section, we provide information about the occurrence of
marine mammals, including density or other relevant information that
will inform the take calculations. Unless otherwise specified, the term
``pile driving'' in this section, and all following sections, may refer
to either pile installation or removal. NMFS has carefully reviewed the
Navy's analysis and concludes that it represents an appropriate and
accurate method for estimating incidental take that may be caused by
the Navy's activities.
Daily occurrence estimates of marine mammals in the project area
are based upon the Year 4 IHA monitoring report from the Fuel Pier
Replacement Project (NAVFAC SW, 2017b). Year 4 is expected to be most
representative of typical species occurrences as this monitoring period
had the highest number of activity days and the highest average number
of animals observed per day for the three most common species in the
area (California sea lion, harbor seal, bottlenose dolphin), with the
exception of Year 2. However, Year 2 was an El Ni[ntilde]o year and not
considered representative of typical species occurrences. The Year 2
monitoring report data was used for any species not observed in Year 4
(common dolphin, Pacific white-sided dolphin, northern elephant seal)
(NAVFAC SW, 2015) (Table 7). Years 1, 3, and 5 included significantly
less monitoring effort than Years 2 and 4, and may also not be
representative of typical species richness and occurrences.
Table 7--Total and Daily Species Occurrences During Years 2 and 4 IHA Monitoring
----------------------------------------------------------------------------------------------------------------
Year 2 IHA (100 monitoring Year 4 IHA (152 monitoring
days; El Nino year) days)
Species ---------------------------------------------------------------
Average per Average per
Total observed day Total observed day
----------------------------------------------------------------------------------------------------------------
California sea lion............................. 7,507 75.1 2,263 * 14.9
Harbor seal..................................... 248 2.5 88 * 0.6
Bottlenose dolphin.............................. 695 7 67 * 0.4
Common dolphin.................................. 850 * 8.5 N/a N/a
Pacific white-sided dolphin..................... 27 * 0.3 N/a N/a
Northern elephant seal.......................... \1\ 1 \1\ 1 N/a N/a
----------------------------------------------------------------------------------------------------------------
* Mean estimate used for daily occurrences for current analysis.
\1\ Same individual hauled out each day.
Year 4 monitoring consisted of the longest effort of all 5 IHA
years for the Navy Fuel Pier Replacement Project, and daily occurrence
estimates for California sea lions, harbor seals, and bottlenose
dolphins were selected from this year. Common dolphins, Pacific white-
sided dolphins, and northern elephant seals were not sighted in Year 4;
however, these species were sighted in Year 2 monitoring. Pacific
white-sided dolphins were only sighted during this year. Daily
occurrence estimates for common dolphins and Pacific white-sided
dolphins were selected from Year 2. Only one northern elephant seal was
sighted during the Year 2 monitoring, and the same individual was
hauled out each day. Using a daily occurrence estimate from past
monitoring was, therefore, not an accurate approach for estimating
occurrence of northern elephant seals. Past monitoring efforts,
including the one northern elephant seal sighted during Year 2
monitoring and a sighting north of the project area, (McConchie, 2015;
NAVFAC SW, 2015) documented a total of two juvenile northern elephant
seals in the project area, as described in the Description of Marine
Mammals in Areas of Specified Activities section in the proposed IHA
(87 FR 68442, November 15, 2022). Due to increasing stock numbers,
there is a reasonable probability that this species could be sighted in
the project area during construction activities. Instead of using past
monitoring data to estimate daily occurrence, it is expected that two
northern elephant seals may be observed in the project area during
construction activities, based upon previous sighting data. The Navy
added a buffer of five seals to this estimate for a total of seven
expected elephant seals in the area during construction activities, and
NMFS agrees with this approach.
Monitoring during Year 4 yielded an observation of 2,263 California
sea lions over the course of the 152-day monitoring period. These
observations equate to an average of 14.9 California sea lions observed
per day, and approximately 15 California sea lions expected to be in
the vicinity of Pier 302, when this estimate is rounded.
Based upon monitoring during Year 4, 88 harbor seals were observed
over the course of the 152-day monitoring period. These observations
equate to an average of 0.6 harbor seals observed per day, and
approximately 1 seal per day expected to be in the vicinity of Pier 302
when this estimate is rounded.
Monitoring during Year 4 yielded an observation of 67 bottlenose
dolphins in the project area over the course of the 152-day monitoring
period. This observation equates to an average of 0.4, or 1 if rounded,
bottlenose dolphins expected to be in the vicinity of Pier 302 each day
of the construction activities.
During Year 2 monitoring, 850 common dolphins were sighted in the
project area over the course of the 152-day monitoring period. This
equates to an average of 8.5 common dolphins observed per day. When
rounded to the nearest whole number, 9.0 individuals are expected to be
sighted per day in the vicinity of Pier 302.
Monitoring during Year 2 documented 7 sightings of Pacific white-
sided dolphins, comprising 27 individuals, with an average of 0.28
individuals sighted per day of monitoring. Rounding this estimate to
the nearest whole number leads to 1.0 individual per day to be expected
to be
[[Page 6710]]
in the vicinity of Pier 302 during the construction activities.
Take Estimation
Here we describe how the information provided above is synthesized
to produce a quantitative estimate of the take that is reasonably
likely to occur.
Daily occurrence estimates were multiplied by the number of days of
pile removal and installation (32 days) to calculate estimated take by
Level B harassment of California sea lions, harbor seals, bottlenose
dolphins, common dolphins, Pacific white-sided dolphins, and northern
elephant seals (Table 8).
Table 8--Authorized Takes by Level B Harassment and Percent of Stock Authorized for Take
----------------------------------------------------------------------------------------------------------------
Expected daily Authorized take Percentage of
Species average by Level B stock authorized
individuals harassment for take
----------------------------------------------------------------------------------------------------------------
California sea lion \1\................................ 15 480 0.19
Harbor seal \1\........................................ 1 32 0.10
Bottlenose dolphin \1\................................. 1 32 7.1
Common dolphin (long and short beaked) \2\............. 9 288 * 0.35
Pacific white-sided dolphin \2\........................ 1 32 0.09
Northern elephant seal................................. (\3\) 7 0.004
----------------------------------------------------------------------------------------------------------------
\1\ Average daily counts based on observations during Year 4 Fuel Pier Replacement Project Monitoring (NAVFAC
SW, 2017b).
\2\ Average daily counts based on observations during Year 2 Fuel Pier Replacement Project Monitoring (NAVFAC
SW, 2015).
\3\ Expected potential of two northern elephant seals over the duration of project activity with a +5 buffer for
Level B Take.
* Percent population calculated for each stock of common dolphins. Percentage in the table represents the
percent of take of long-beaked common dolphins as this would be a greater percentage than if all take were
attributed to short-beaked common dolphins (0.03 percent).
By using the sighting-based approach, take values are not affected
by the estimated harassment distances from Tables 5 and 6. Given the
very small Level A harassment isopleths for all species and mitigation
measures, no take by Level A harassment is anticipated or authorized.
Mitigation
In order to issue an IHA under section 101(a)(5)(D) of the MMPA,
NMFS must set forth the permissible methods of taking pursuant to the
activity, and other means of effecting the least practicable impact on
the species or stock and its habitat, paying particular attention to
rookeries, mating grounds, and areas of similar significance, and on
the availability of the species or stock for taking for certain
subsistence uses (latter not applicable for this action). NMFS
regulations require applicants for incidental take authorizations to
include information about the availability and feasibility (economic
and technological) of equipment, methods, and manner of conducting the
activity or other means of effecting the least practicable adverse
impact upon the affected species or stocks, and their habitat (50 CFR
216.104(a)(11)).
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, NMFS
considers two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned), and;
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, and impact on
operations.
Shutdown Zones
Before the commencement of in-water construction activities, the
Navy will establish shutdown zones for all activities. The purpose of a
shutdown zone is to define an area within which shutdown of the
activity would occur upon sighting of a marine mammal (or in
anticipation of an animal entering the defined area). During all in-
water construction activities, the Navy will implement a standard 20 m
(66 ft) shutdown zone, with the exception of a 70 m (230 ft) zone for
phocids during the use of impact pile driving for the 24-inch octagonal
concrete piles. These distances exceed the estimated Level A harassment
distances (Table 10). During the impact installation of the 24-inch
octagonal concrete piles, the shutdown zone for phocids will be
buffered to 70 m (230 ft) to encompass the Level A harassment zone.
Adherence to this expanded shutdown zone will avoid the potential for
the take of phocids by Level A harassment during impact pile driving.
If a marine mammal enters a buffered shutdown zone, in-water activities
will be stopped until visual confirmation that the animal has left the
zone or the animal is not sighted for 15 minutes.
All marine mammals will be monitored in the Level B harassment
zones and throughout the area as far as visual monitoring can take
place. If a marine mammal enters the Level B harassment zone, in-water
activities will continue and the animal's presence within the estimated
harassment zone will be documented.
The Navy will also establish shutdown zones for all marine mammals
for which take has not been authorized or for which incidental take has
been authorized, but the authorized number of takes has been met. These
zones are equivalent to the Level B harassment zones for each activity.
If a marine mammal species not covered under this IHA enters the
shutdown zone, all in-water activities will cease until the animal
leaves the zone or has not been observed for at least 1 hour, and NMFS
will be notified about species and precautions taken. Pile removal will
proceed if the non-IHA species is observed to leave the Level B
harassment zone or if 1 hour has passed since the last observation.
If shutdown and/or clearance procedures would result in an imminent
safety concern, as determined by the Navy, the in-water activity will
be allowed to continue until the safety concern has been addressed, and
the animal will be continuously monitored. The Navy Point of Contact
(POC) will be consulted before re-commencing activities.
[[Page 6711]]
Table 9--Shutdown Zones and Level B Harassment Zones
----------------------------------------------------------------------------------------------------------------
Shutdown zones m (ft) Level B
Method Pile size/type ------------------------------------------------ harassment
MF PW OW zones m (ft)
----------------------------------------------------------------------------------------------------------------
Pile Removal Activities
----------------------------------------------------------------------------------------------------------------
Vibratory Extraction.......... 18'' Octagonal 20 (66) 20 (66) 20 (66) 1,445 (4,742)
Concrete.
18'' Steel Pipe. 20 (66) 20 (66) 20 (66) 575 (1,888)
----------------------------------------------------------------------------------------------------------------
Pile Installation Activities
----------------------------------------------------------------------------------------------------------------
Impact Pile Driving........... 24'' Octagonal 20 (66) \1\ 70 (230) 20 (66) 117 (383)
Concrete.
14'' Square 20 (66) 20 (66) 20 (66) 25 (82)
Concrete.
Vibratory Hammer.............. 6'' Round Steel. 20 (66) 20 (66) 20 (66) 494 (1,619)
----------------------------------------------------------------------------------------------------------------
\1\ Level A ZOI buffered from 62.5 m up to 70 m.
Protected Species Observers
The placement of protected species observers (PSOs) during all pile
driving activities (described in the Monitoring and Reporting section)
will ensure that the entire shutdown zone is visible. Should
environmental conditions deteriorate such that the entire shutdown zone
would not be visible (e.g., fog, heavy rain), pile driving will be
delayed until the PSO is confident marine mammals within the shutdown
zone could be detected.
Pre-Activity Monitoring
Prior to the start of daily in-water construction activity, or
whenever a break in pile driving of 30 minutes or longer occurs, PSOs
will observe the shutdown and monitoring zones for a period of 30
minutes. The shutdown zone will be considered cleared when a marine
mammal has not been observed within the zone for that 30-minute period.
If a marine mammal is observed within the shutdown zones listed in
Table 10, pile driving activity will be delayed or halted. If work
ceases for more than 30 minutes, the pre-activity monitoring of the
shutdown zones will commence. A determination that the shutdown zone is
clear must be made during a period of good visibility (i.e., the entire
shutdown zone and surrounding waters must be visible to the naked eye).
Soft-Start Procedures
Soft-start procedures provide additional protection to marine
mammals by providing warning and/or giving marine mammals a chance to
leave the area prior to the hammer operating at full capacity. For
impact pile driving, contractors will be required to provide an initial
set of three strikes from the hammer at reduced energy, followed by a
30-second waiting period, then two subsequent reduced-energy strike
sets. Soft-start will be implemented at the start of each day's impact
pile driving and at any time following cessation of impact pile driving
for a period of 30 minutes or longer.
Based on our evaluation of the applicant's measures, NMFS has
determined that the mitigation measures provide the means of effecting
the least practicable impact on the affected species or stocks and
their habitat, paying particular attention to rookeries, mating
grounds, and areas of similar significance.
Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and,
Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring during pile driving activities will be
conducted by PSOs meeting NMFS' following requirements:
Independent PSOs (i.e., not construction personnel) who
have no other assigned tasks during monitoring periods will be used;
At least one PSO will have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
incidental take authorization;
Other PSOs may substitute education (degree in biological
science or related field) or training for prior experience performing
the duties of a PSO during construction activity pursuant to a NMFS-
issued incidental take authorization; and
A minimum of two PSOs must be on duty for all in-water
construction activities. A lead observer or monitoring coordinator must
be designated to
[[Page 6712]]
coordinate monitoring and log project and monitoring activity data. The
lead observer must have prior experience performing the duties of a PSO
during construction activity pursuant to a NMFS-issued incidental take
authorization.
PSOs must be approved by NMFS prior to beginning any
activity subject to this IHA.
PSOs will have the following additional qualifications:
Ability to conduct field observations and collect data
according to assigned protocols;
Experience or training in the field identification of
marine mammals, including the identification of behaviors;
Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
The Navy will have at least two PSOs stationed at the best possible
vantage points in the project area to monitor during all pile driving
activities. If a PSO sights a marine mammal in the shutdown zone, the
PSO must alert the ``command'' PSO to notify the equipment operator to
shut down. If the ``command'' PSO does not respond, any PSO has the
authority to notify the need for a shutdown. If the ``command'' PSO
calls for a shutdown, the ``command'' PSO will let the contractor know
when activities can re-commence. Additional PSOs may be employed during
periods of low or obstructed visibility to ensure the entirety of the
shutdown zones are monitored. A marine mammal monitoring plan has been
submitted to NMFS for approval.
Reporting
A draft marine mammal monitoring report will be submitted to NMFS
within 90 days after the completion of pile driving activities, or 60
days prior to a requested date of issuance of any future IHAs for the
project, or other projects at the same location, whichever comes first.
A final report must be prepared and submitted within 30 calendar days
following receipt of any NMFS comments on the draft report. If no
comments are received from NMFS within 30 calendar days of receipt of
the draft report, the report shall be considered final. All draft and
final monitoring reports must be submitted to
[email protected] and [email protected]. The marine
mammal monitoring report will include an overall description of work
completed, a narrative regarding marine mammal sightings, and
associated PSO data sheets. Specifically, the report will include:
Dates and times (begin and end) of all marine mammal
monitoring;
Construction activities occurring during each daily
observation period, including: (a) How many and what type of piles were
driven or removed and the method (i.e., impact or vibratory); and (b)
the total duration of time for each pile (vibratory driving) number of
strikes for each pile (impact driving);
PSO locations during marine mammal monitoring; and
Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance.
PSOs will record all incidents of marine mammal occurrence,
regardless of distance from activity, and will document any behavioral
reactions in concert with distance from piles being driven or removed.
Specifically, PSOs will record the following:
Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting;
Time of sighting;
Identification of the animal(s) (e.g., genus/species,
lowest possible taxonomic level, or unidentified), PSO confidence in
identification, and the composition of the group if there is a mix of
species;
Distance and location of each observed marine mammal
relative to the pile being driven or hole being drilled for each
sighting;
Estimated number of animals (min/max/best estimate);
Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.);
Description of any marine mammal behavioral observations
(e.g., observed behaviors such as feeding or traveling), including an
assessment of behavioral responses thought to have resulted from the
activity (e.g., no response or changes in behavioral state such as
ceasing feeding, changing direction, flushing, or breaching).
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, the Navy will report the
incident to the Office of Protected Resources (OPR)
([email protected]), NMFS and to the West Coast
regional stranding network (866-767-6114) as soon as feasible. If the
death or injury was clearly caused by the specified activity, the Navy
will immediately cease the specified activities until NMFS is able to
review the circumstances of the incident and determine what, if any,
additional measures are appropriate to ensure compliance with the terms
of the IHAs. The Navy will not resume their activities until notified
by NMFS.
The report will include the following information:
1. Time, date, and location (latitude/longitude) of the first
discovery (and updated location information if known and applicable);
2. Species identification (if known) or description of the
animal(s) involved;
3. Condition of the animal(s) (including carcass condition if the
animal is dead);
4. Observed behaviors of the animal(s), if alive;
5. If available, photographs or video footage of the animal(s); and
6. General circumstances under which the animal was discovered.
Negligible Impact Analysis and Determination
NMFS has defined negligible impact as an impact resulting from the
specified activity that cannot be reasonably expected to, and is not
reasonably likely to, adversely affect the species or stock through
effects on annual rates of recruitment or survival (50 CFR 216.103). A
negligible impact finding is based on the lack of likely adverse
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough
information on which to base an impact determination. In addition to
considering estimates of the number of marine mammals that might be
``taken'' through harassment, NMFS considers other factors, such as the
likely nature of any impacts or responses (e.g., intensity, duration),
the context of any impacts or responses (e.g., critical reproductive
time or location, foraging impacts affecting energetics), as well as
effects on habitat, and the likely effectiveness of the mitigation. We
also assess the number, intensity, and context of estimated takes by
evaluating
[[Page 6713]]
this information relative to population status. Consistent with the
1989 preamble for NMFS' implementing regulations (54 FR 40338,
September 29, 1989), the impacts from other past and ongoing
anthropogenic activities are incorporated into this analysis via their
impacts on the baseline (e.g., as reflected in the regulatory status of
the species, population size and growth rate where known, ongoing
sources of human-caused mortality, or ambient noise levels).
To avoid repetition, the discussion of our analysis applies to all
the species listed in Table 1, given that the anticipated effects of
this activity on these different marine mammal stocks are expected to
be similar. There is little information about the nature or severity of
the impacts, or the size, status, or structure of any of these species
or stocks that would lead to a different analysis for this activity.
Level A harassment is extremely unlikely given the small size of
the Level A harassment isopleths and the required mitigation measures
designed to minimize the possibility of injury to marine mammals. No
mortality is anticipated given the nature of the activity.
Pile installation and removal activities have the potential to
disturb or displace marine mammals. Specifically, the project
activities may result in take, in the form of Level A and Level B
harassment from underwater sounds generated from impact and vibratory
pile installation, and vibratory pile removal activities. Potential
takes could occur if individuals move into the ensonified zones when
these activities are underway.
The takes from Level B harassment will be due to potential
behavioral disturbance. No serious injury or mortality is anticipated
for any stocks presented in this analysis given the nature of the
activity and mitigation measures designed to minimize the possibility
of injury. The potential for harassment is minimized through
construction methods and the implementation of planned mitigation
strategies (see Mitigation section).
Take will occur within a limited, confined area of each stock's
range. Level B harassment will be reduced to the level of least
practicable adverse impact through use of mitigation measures described
herein. Further, the amount of take authorized is extremely small when
compared to stock abundance.
No marine mammal stocks for which incidental take authorization is
authorized are listed as threatened or endangered under the ESA or
determined to be strategic or depleted under the MMPA. The relatively
low marine mammal occurrences in the area, small shutdown zones, and
planned monitoring make injury takes of marine mammals unlikely. The
shutdown zones will be thoroughly monitored before the vibratory pile
installation and removal begins, and construction activities will be
postponed if a marine mammal is sighted within the shutdown zone. There
is a high likelihood that marine mammals will be detected by trained
observers under environmental conditions described for the project.
Limiting construction activities to daylight hours will also increase
detectability of marine mammals in the area. Therefore, the mitigation
and monitoring measures are expected to eliminate the potential for
injury and Level A harassment as well as reduce the amount and
intensity for Level B behavioral harassment. Furthermore, the pile
installation and removal activities analyzed here are similar to, or
less impactful than, numerous construction activities conducted in
other similar locations which have occurred with no reported injuries
or mortality to marine mammals, and no known long-term adverse
consequences from behavioral harassment.
Anticipated and authorized takes are expected to be limited to
short-term Level B harassment (behavioral disturbance) as construction
activities will occur over the course of 32 weeks. Effects on
individuals taken by Level B harassment, based upon reports in the
literature as well as monitoring from other similar activities, may
include increased swimming speeds, increased surfacing time, or
decreased foraging (e.g., Thorson and Reyff, 2006; NAVFAC SW, 2018b).
Individual animals, even if taken multiple times, will likely move away
from the sound source and be temporarily displaced from the area due to
elevated noise level during pile removal. Marine mammals could also
experience TTS if they move into the Level B monitoring zone. TTS is a
temporary loss of hearing sensitivity when exposed to loud sound, and
the hearing threshold is expected to recover completely within minutes
to hours. Thus, it is not considered an injury. While TTS could occur,
it is not considered a likely outcome of this activity. Repeated
exposures of individuals to levels of sounds that could cause Level B
harassment are unlikely to considerably significantly disrupt foraging
behavior or result in significant decrease in fitness, reproduction, or
survival for the affected individuals. In all, there will be no adverse
impacts to the stock as a whole.
The project is not expected to have significant adverse effects on
marine mammal habitat. There are no Biologically Important Areas or
ESA-designated critical habitat within the project area, and the
activities will not permanently modify existing marine mammal habitat.
The activities may cause fish to leave the area temporarily. This could
impact marine mammals' foraging opportunities in a limited portion of
the foraging range, however, due to the short duration of activities
and the relatively small area of affected habitat, the impacts to
marine mammal habitat are not expected to cause significant or long-
term negative consequences.
In combination, we believe that these factors, as well as the
available body of evidence from other similar activities, demonstrate
that the potential effects of the specified activities would have only
minor, short-term effects on individuals. The specified activities are
not expected to impact reproduction or survival of any individual
marine mammals, much less affect rates of recruitment or survival and
would therefore not result in population-level impacts.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect any of the species or stocks
through effects on annual rates of recruitment or survival:
No serious injury or mortality or Level A harassment is
anticipated or authorized;
The specified activity and associated ensonified areas are
very small relative to the overall habitat ranges of all species;
Biologically important areas or critical habitat have not
been identified within the project area;
The lack of anticipated significant or long-term effects
to marine mammal habitat;
The Navy is required to implement mitigation measures to
minimize impacts, such as PSO observation and shutdown zones of 20 m
(66 ft); and,
Monitoring reports from similar work in San Diego Bay have
documented little to no effect on individuals of the same species
impacted by the specified activities.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the monitoring and mitigation
measures, NMFS finds that the total marine mammal take from the
authorized
[[Page 6714]]
activity will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted previously, only small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
The amount of take NMFS has authorized is below one-third of the
estimated stock abundances for all seven species (refer back to Table
8). For most requested species, the authorized take of individuals is
less than 1 percent of the abundance of the affected stock (with
exception for bottlenose dolphins at 7.1 percent). This is likely a
conservative estimate because it assumes all takes are of different
individual animals, which is likely not the case. Some individuals may
return multiple times in a day, but PSOs will count them as separate
takes if they cannot be individually identified.
Based on the analysis contained herein of the authorized activity
(including the mitigation and monitoring measures) and the anticipated
take of marine mammals, NMFS finds that small numbers of marine mammals
will be taken relative to the population size of the affected species
or stocks.
Unmitigable Adverse Impact Analysis and Determination
There are no relevant subsistence uses of the affected marine
mammal stocks or species implicated by this action. Therefore, NMFS has
determined that the total taking of affected species or stocks would
not have an unmitigable adverse impact on the availability of such
species or stocks for taking for subsistence purposes.
Endangered Species Act
Section 7(a)(2) of the Endangered Species Act of 1973 (ESA; 16
U.S.C. 1531 et seq.) requires that each Federal agency insure that any
action it authorizes, funds, or carries out is not likely to jeopardize
the continued existence of any endangered or threatened species or
result in the destruction or adverse modification of designated
critical habitat. To ensure ESA compliance for the issuance of IHAs,
NMFS consults internally whenever we propose to authorize take for
endangered or threatened species.
No incidental take of ESA-listed species is authorized or expected
to result from this activity. Therefore, NMFS has determined that
formal consultation under section 7 of the ESA is not required for this
action.
National Environmental Policy Act
To comply with the National Environmental Policy Act of 1969 (NEPA;
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A,
NMFS must review our action (i.e., the issuance of an IHA) with respect
to potential impacts on the human environment.
This action is consistent with categories of activities identified
in Categorical Exclusion B4 (IHAs with no anticipated serious injury or
mortality) of the Companion Manual for NOAA Administrative Order 216-
6A, which do not individually or cumulatively have the potential for
significant impacts on the quality of the human environment and for
which we have not identified any extraordinary circumstances that would
preclude this categorical exclusion. Accordingly, NMFS has determined
that the issuance of the IHA qualifies to be categorically excluded
from further NEPA review.
Authorization
NMFS has issued an IHA to the U.S. Navy for the potential
harassment of small numbers of six marine mammal species incidental to
construction activities associated with the Naval Base Point Loma Pier
302 Replacement Project in San Diego, California., provided the
previously mentioned mitigation, monitoring, and reporting requirements
are followed.
Dated: January 27, 2023.
Kimberly Damon-Randall,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2023-02107 Filed 1-31-23; 8:45 am]
BILLING CODE 3510-22-P