Notice2023-10623
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Chevron Long Wharf Maintenance and Efficiency Project in San Francisco Bay, California
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
May 18, 2023
Effective
June 1, 2023
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 the NMFS has issued an incidental harassment authorization (IHA) to Chevron Products Company (Chevron) to incidentally harass, by Level B harassment only, marine mammals during construction activities associated with the Long Wharf Maintenance and Efficiency Project (LWMEP) in San Francisco Bay, California.
Full Text
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<title>Federal Register, Volume 88 Issue 96 (Thursday, May 18, 2023)</title>
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[Federal Register Volume 88, Number 96 (Thursday, May 18, 2023)]
[Notices]
[Pages 31703-31715]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-10623]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XC916]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to the Chevron Long Wharf Maintenance
and Efficiency Project in San Francisco Bay, California
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; issuance of 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
the NMFS has issued an incidental harassment authorization (IHA) to
Chevron Products Company (Chevron) to incidentally harass, by Level B
harassment only, marine mammals during construction activities
associated with the Long Wharf Maintenance and Efficiency Project
(LWMEP) in San Francisco Bay, California.
DATES: This authorization is effective from June 1, 2023 through May
31, 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,
[[Page 31704]]
may be obtained online at: <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>. 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 December 16, 2022, NMFS received a request from Chevron Products
Company (Chevron) for an IHA to take marine mammals incidental to pile
driving activities associated with the LWMEP in San Francisco Bay (the
Bay), California. Following NMFS' review of the application, Chevron
submitted a final revised version on February 27, 2023. The application
was deemed adequate and complete on March 20, 2023. Chevron's request
is for take of 7 species of marine mammals by Level B harassment only.
Neither Chevron nor NMFS expect serious injury or mortality to result
from this activity and, therefore, an IHA is appropriate.
NMFS previously issued IHAs to Chevron for similar work (83 FR
27548, June 13, 2018; 84 FR 28474, June 19, 2019; 85 FR 37064, June 19,
2020; 86 FR 28578, May 27, 2021; 87 FR 35180, June 9, 2022). Chevron
complied with all the requirements (e.g., mitigation, monitoring, and
reporting) of the previous IHAs, and information regarding their
monitoring results may be found in the Estimated Take section.
The IHA will cover 1 year of a larger project for which Chevron
obtained prior IHAs and intends to request take authorization for
subsequent facets of the project. The larger 5-year project involves
upgrading Long Wharf to satisfy current Marine Oil Terminal Engineering
and Maintenance Standards.
There are no changes from the proposed IHA to the final IHA.
Description of Activity
Overview
Chevron plans to upgrade Berth 1 of the Refinery Long Wharf in the
Bay, California in order to meet current safety and efficiency
standards. As part of the project, Chevron will use vibratory
extraction to remove concrete piles associated with the existing
gangway and catwalk. Impact hammers will be used to install concrete
piles to construct a mooring dolphin and hook, breasting dolphin and
breasting points with standoff fenders, and to replace the catwalk in a
different location. A temporary construction template composed of steel
piles will be installed through the use of a vibratory hammer and
removed by vibratory extraction when in-water construction activities
are complete. The Long Wharf has six berths for receiving raw materials
and shipping products. The project area encompasses the entirety of
Berth 1, an area of approximately 470 square meters (m\2\). All in-
water work will take place within the seasonal work window of June 1,
2023 through November 30, 2023. Unless otherwise specified, the term
``pile driving'' may refer to either pile installation or removal.
Chevron's activity includes impact and vibratory pile driving and
vibratory pile removal, which may result in the incidental take of
marine mammals, by harassment only. Due to mitigation measures, no
Level A harassment is anticipated to occur, and none is authorized.
A detailed description of the planned construction project is
provided in the Federal Register notice for the proposed IHA (88 FR
19247, March 31, 2023). Since that time, no changes have been made to
the planned construction activities. Therefore, a detailed description
is not provided here. Please refer to that Federal Register notice for
a 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 Chevron was published
in the Federal Register on March 31, 2023 (88 FR 19237). That notice
described, in detail, Chevron's activity, the marine mammal species
that may be affected by the activity, and the anticipated effects on
marine mammals. In that notice, we requested public input on the
request for authorization described therein, our analyses, the proposed
authorization, and any other aspect of the notice of proposed IHA, and
requested that interested persons submit relevant information,
suggestions, and comments. During the 30-day public comment period,
NMFS did not receive any public comments.
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, instead of reprinting the information. Additional
information regarding population trends and threats may be found in
NMFS' Stock Assessment Reports (SARs; <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">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' website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 1 lists all species or stocks for which take is expected and
authorized for this activity, and summarizes information related to the
population or stock, including regulatory status under the MMPA and
Endangered Species Act (ESA) and potential biological removal (PBR),
where known. PBR is defined by the MMPA as the maximum number of
animals, not including natural mortalities, that may be removed from a
marine mammal stock while allowing that stock to reach or maintain its
optimum sustainable population (as described in NMFS' SARs). While no
serious injury or mortality is anticipated
[[Page 31705]]
or authorized here, PBR and annual serious injury and mortality from
anthropogenic sources are included here as gross indicators of the
status of the species or stocks and other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS' stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS' U.S. Pacific SARs. All values presented in Table 1 are the most
recent available at the time of publication (including from the draft
2022 SARs) and are available online at: <a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>.
Table 1--Marine Mammal Species \4\ Likely To Be Impacted by the Specified Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stock abundance
ESA/MMPA status; (CV, Nmin, most Annual M/SI
Common name Scientific name Stock strategic (Y/N) \1\ recent abundance PBR \3\
survey) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Artiodactyla--Infraorder Cetacea--Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
Gray whale................... Eschrichtius Eastern North -, -, N............. 26,960 (0.05, 801 131
robustus. Pacific. 25,849, 2016).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
Bottlenose dolphin........... Tursiops truncatus.. California Coastal.. -, -, N............. 453 (0.06, 346, 2.7 >=2.0
2011).
Family Phocoenidae (porpoises):
Harbor porpoise.............. Phocoena phocoena... San Francisco/ -, -, N............. 7,777 (0.62, 4,811, 73 >=0.4
Russian River. 2017).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Order Carnivora--Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
California sea lion.......... Zalophus U.S................. -, -, N............. 257,606 (N/A, 14,011 >321
californianus. 233,515, 2014).
Northern fur seal \5\........ Callorhinus ursinus. California.......... -, D, N............. 14,050 (N/A, 7,524, 451 1.8
2013).
Family Phocidae (earless seals):
Harbor seals................. Phoca vitulina...... California.......... -, -, N............. 30,968 (N/A, 1,641 43
27,348, 2012).
Northern elephant seal....... Mirounga California Breeding. -, -, N............. 187,386 (N/A, 5,122 13.7
angustirostris. 85,369, 2013).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <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. In some cases, CV is not applicable as in the case of
the pinnipeds, as population estimates are dependent upon the numbers of individuals hauled out or the number of pups.
\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
(<a href="https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/">https://marinemammalscience.org/science-and-publications/list-marine-mammal-species-subspecies/</a>; Committee on Taxonomy (2022)).
\5\ Survey years = Sea Lion Rock--2014; St. Paul and St. George Is--2014, 2016, 2018; Bogoslof Is.--2015, 2019.
As indicated above, all seven species (with seven managed stocks)
in Table 2 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. All species that could
potentially occur in the project area are included in Table 4-1 of the
IHA application. While humpback whales have been sighted in the coastal
waters outside of the Bay, the spatial occurrence of this species is
such that take is not expected to occur, and they are not discussed
further beyond the explanation provided here. Although there are no
published studies available regarding the distribution of humpback
whales in the Bay, sightings from whale watching vessels and other
mariners report that when humpback whales enter the Bay, they rarely
move east into the Bay towards the vicinity of the project area and are
unlikely to occur during the activities.
A detailed description of the species likely to be affected by the
pile driving activities, including brief introductions to the species
and relevant stocks as well as available information regarding
population trends and threats, and information regarding local
occurrence,
[[Page 31706]]
were provided in the Federal Register notice for the proposed IHA (88
FR 19247, March 31, 2023); since that time, we are not aware of any
changes in the status of these species and stocks; therefore, detailed
descriptions are not provided here. Please refer to that Federal
Register notice for these descriptions. Please also refer to NMFS'
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>) for generalized
species accounts.
Marine Mammal Hearing
Hearing is the most important sensory modality for marine mammals
underwater, and exposure to anthropogenic sound can have deleterious
effects. To appropriately assess the potential effects of exposure to
sound, it is necessary to understand the frequency ranges marine
mammals are able to hear. Not all marine mammal species have equal
hearing capabilities (e.g., Richardson et al., 1995; Wartzok and
Ketten, 1999; Au and Hastings, 2008). To reflect this, Southall et al.
(2007, 2019) recommended that marine mammals be divided into hearing
groups based on directly measured (behavioral or auditory evoked
potential techniques) or estimated hearing ranges (behavioral response
data, anatomical modeling, etc.). Note that no direct measurements of
hearing ability have been successfully completed for mysticetes (i.e.,
low-frequency cetaceans). Subsequently, NMFS (2018) described
generalized hearing ranges for these marine mammal hearing groups.
Generalized hearing ranges were chosen based on the approximately 65
decibel (dB) threshold from the normalized composite audiograms, with
the exception for lower limits for low-frequency cetaceans where the
lower bound was deemed to be biologically implausible and the lower
bound from Southall et al. (2007) retained. Marine mammal hearing
groups and their associated hearing ranges are provided in Table 2.
Table 2--Marine Mammal Hearing Groups
[NMFS, 2018]
------------------------------------------------------------------------
Hearing group Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen 7 Hz to 35 kHz.
whales).
Mid-frequency (MF) cetaceans 150 Hz to 160 kHz.
(dolphins, toothed whales, beaked
whales, bottlenose whales).
High-frequency (HF) cetaceans (true 275 Hz to 160 kHz.
porpoises, Kogia, river dolphins,
Cephalorhynchid, Lagenorhynchus
cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) 50 Hz to 86 kHz.
(true seals).
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 Chevron's pile driving
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of the
proposed IHA (88 FR 19247, March 31, 2023) included a discussion of the
effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from Chevron's pile driving activities on
marine mammals and their habitat. That information and analysis is
incorporated by reference into this final IHA determination and is not
repeated here; please refer to the notice of the proposed IHA (88 FR
19247, March 31, 2023).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
authorized through this IHA, which informed both NMFS' consideration of
``small numbers,'' and the negligible impact determinations.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would 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., shutdown zones, protected species observers (PSOs)
monitoring) discussed in detail below in the Mitigation section, Level
A harassment is neither anticipated nor authorized.
As described previously, no serious injury or mortality is
anticipated or authorized for this activity. Below, we describe how the
take numbers are estimated.
For acoustic impacts, generally speaking, we estimate take by
considering: (1) acoustic thresholds above which NMFS believes the best
available science indicates marine mammals will be behaviorally
harassed or incur some degree of permanent hearing impairment; (2) the
area or volume of water that will be ensonified above these levels in a
day; (3) the density or occurrence of marine mammals within these
ensonified areas; and (4) the number of days of activities. We note
that while these factors can contribute to a basic calculation to
provide an initial prediction of potential takes, additional
information that can qualitatively inform take estimates is also
sometimes available (e.g., previous monitoring results or average group
size). Below, we describe the factors considered here in more detail
and present the take estimates.
[[Page 31707]]
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 RMS
pressure received levels (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.
Chevron's pile driving activities include the use of continuous
(vibratory pile-driving) and impulsive (impact pile-driving) sources,
and therefore the RMS SPL thresholds of 120 and 160 dB re 1 [mu]Pa are
applicable.
Level A harassment--NMFS' Technical Guidance for Assessing the
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0)
(Technical Guidance, 2018) identifies dual criteria to assess auditory
injury (Level A harassment) to five different marine mammal groups
(based on hearing sensitivity) as a result of exposure to noise from
two different types of sources (impulsive or non-impulsive). Chevron's
pile driving activities include 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:
<a href="http://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lp,0-pk,flat: 219 Cell 2: LE,p,LF,24h: 199 dB.
dB; LE,p,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lp,0-pk,flat: 230 Cell 4: LE,p,MF,24h: 198 dB.
dB; LE,p,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lp,0-pk,flat: 202 Cell 6: LE,p,HF,24h: 173 dB.
dB; LE,p,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lp,0-pk,flat: 218 Cell 8: LE,p,PW,24h: 201 dB.
dB; LE,p,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lp,0-pk,flat: 232 Cell 10: LE,p,OW,24h: 219 dB.
dB; LE,p,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS
onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level thresholds
associated with impulsive sounds, these thresholds are recommended for consideration.
Note: Peak sound pressure level (Lp,0-pk) has a reference value of 1 [micro]Pa, and weighted cumulative sound
exposure level (LE,p) has a reference value of 1[micro]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.
Pile driving activities, using an impact hammer as well as a
vibratory hammer, will generate underwater noise that could result in
disturbance to marine mammals near the project area. A review of
underwater sound measurements for similar projects was conducted to
estimate the near-source sound levels for impact and vibratory pile
driving and vibratory extraction. Source levels for removal and
installation activities derived from this review are shown in Table 4.
[[Page 31708]]
Table 4--Source Levels for Pile Removal and Installation Activities
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source levels (dB)/source distance (m)
---------------------------------------------------------
Method Pile type Peak sound Mean maximum RMS Reference
pressure (dB re 1 SPL (dB re 1 SEL \1\ (dB re 1
[mu]Pa) [mu]Pa) [mu]Pa2 sec)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact install \2\.................. 24-inch square 191/10 173/10 161/10 AECOM (2018, 2019).
concrete pile.
Vibratory install/extract........... 36-inch steel shell 196/10 167/15 167 AECOM (2019).
pile.
Vibratory extract \3\............... 18-inch concrete pile. N/A 163/10 150 NAVFAC SW (2022).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Sound exposure level (SEL).
\2\ Chevron will use a bubble curtain attenuation system for all impact pile driving. NMFS conservatively assumes that the bubble curtain will result in
a 5 dB reduction in sound. These source levels incorporate the 5 dB reduction.
\3\ 20-inch concrete piles used as a proxy as vibratory data for 18-inch concrete piles was not available.
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 topography. The general formula for
underwater TL is:
TL = B * Log10 (R<INF>1</INF>/R<INF>2</INF>),
Where
TL = transmission loss in dB;
B = transmission loss coefficient;
R<INF>1</INF> = the distance of the modeled SPL from the driven
pile; and
R<INF>2</INF> = the distance from the driven pile of the initial
measurement.
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, known as practical spreading. As
is common practice in coastal waters, here we assume practical
spreading (4.5 dB reduction in sound level for each doubling of
distance) for vibratory extraction of concrete piles, as hydro-acoustic
data for the same pile type was not available for this project site.
Chevron conducted hydro-acoustic monitoring for prior projects at Long
Wharf for the impact driving of 24-inch concrete piles and vibratory
driving of 36-inch steel piles. Based upon hydro-acoustic monitoring
conducted at Long Wharf in 2018 and 2019 (AECOM, 2018, 2019), Chevron
calculated a transmission loss coefficient ranging from 14 to 20 (~4.4
dB to 8 dB per doubling of distance). As this estimate represents a
wide range of measured transmission loss, NMFS applied the standard
value of 15 for impact driving of concrete piles. For vibratory driving
of 36-inch steel piles, Chevron calculated a transmission loss
coefficient of 20.8 to 25.0 (~8 dB to 9 dB per doubling of distance)
from hydro-acoustic monitoring conducted at Long Wharf in 2019 (AECOM,
2019). Given that all available data suggested a higher transmission
loss, NMFS found it appropriate to apply this to its analysis. NMFS
applied the lower of these two values, 20.8 TL, to this analysis to be
conservative. The Level B harassment zones and ensonified areas for
Chevron's activities are shown in Table 5.
Table 5--Distance to Level B Harassment Thresholds and Ensonified Areas
----------------------------------------------------------------------------------------------------------------
Source levels (dB)/source Distance to
distance (m) level B Ensonified
Pile type -------------------------------- harassment area (km\2\)
Peak RMS thresholds (m)
----------------------------------------------------------------------------------------------------------------
Impact Installation:
24-inch square concrete pile................ 191/10 173/10 74 0.02
Vibratory Installation:
36-inch steel shell pile.................... 196/10 167/15 2,727 23.36
Vibratory Extraction:
18-inch concrete pile....................... N/A 163/10 7,356 170
36-inch steel shell pile.................... 196/10 167/15 2,727 17.24
----------------------------------------------------------------------------------------------------------------
Level A Harassment Thresholds--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 the 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 driving activities, the optional User
Spreadsheet tool predicts the closest distance at which a stationary
animal would not be expected to incur PTS if the sound source traveled
by the stationary animal in a straight line at a constant speed. The
isopleths generated by the User Spreadsheet used the same TL
coefficients as the Level B harassment zone calculations, as indicated
above for each activity type. 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
[[Page 31709]]
Federal Register notice for the proposed IHA (88 FR 19247, March 31,
2023). The maximum RMS SPL/SEL SPL as well as peak SPL and resulting
isopleths are reported below in Table 6. The 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 activity.
Table 6--Distance to Level A Harassment Thresholds for Each Marine Mammal Hearing Group
--------------------------------------------------------------------------------------------------------------------------------------------------------
Source levels (dB)/source distance Distances to level A harassment threshold (m)
(m) -------------------------------------------------------------------------------
Pile type --------------------------------------- Phocid Otariid
Peak RMS/SEL Lf cetaceans Mf cetaceans Hf cetaceans pinnipeds pinnipeds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact Installation:
24-inch square concrete pile. 191/10 161/10 SEL........... 31.3 1.1 37.3 16.8 1.2
Vibratory Installation:
36-inch steel shell pile..... 196/10 167/15 RMS........... 15.9 2.8 21 11.1 1.6
Vibratory Extraction:
18-inch concrete pile........ N/A 163/10 RMS........... 3.4 0.3 5 2.1 0.1
36-inch steel shell pile..... 196/10 167/15 RMS........... 15.9 2.8 21 11.1 1.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
Lf = low frequency, Mf = mid-frequency, Hf = high frequency.
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.
Harbor Seal--Limited at-sea densities are available for Pacific
harbor seals in the Bay. To estimate the number of harbor seals
potentially taken by Level B harassment, take estimates were developed
based upon annual surveys of haulouts in the Bay conducted by the
National Park Service (NPS) (Codde and Allen 2013, 2015, 2017, 2020;
Codde, 2020). Harbor seals spend more time hauled out and enter the
water later in the evening during molting season (NPS, 2014). The
molting season occurs from June-July and overlaps with the construction
period of June-November, therefore, haulout counts may provide the most
accurate estimates of harbor seals in the area during that time. Due to
the close proximity of Castro Rocks to the project area, Chevron used
the highest mean value of harbor seals observed hauled out at Castro
Rocks during the molting season in any recent NPS annual survey. The
highest mean number of harbor seals was recorded in 2019 as 237 seals.
There are no systematic counts available to estimate the number of
seals that may be in the water near Long Wharf at any given time and
the number of seals hauled out on Castro Rocks may vary based upon time
of day, tide, and seal activity. Therefore, the analysis assumes that
all 237 seals could swim into the Level B harassment zone each day that
pile driving is occurring.
California sea lion--Although there are no haulout sites for
California sea lions in close proximity to the project area, sea lions
have consistently been sighted in the Bay while monitoring during past
construction projects (AECOM, 2019, 2020, 2021, 2022; Caltrans, 2017).
As limited data is available on the occurrences of California sea lions
in the Bay, NMFS used PSO monitoring data from previous stages of the
LWMEP (AECOM, 2019, 2020, 2021) and Year 1 of the Point Orient Wharf
Removal (POWR) project (AECOM, 2022) to generate a daily occurrence
rate. NMFS calculated daily occurrence rate using the following
equation:
Daily occurrence rate = Total number of animals sighted/Total
monitoring days.
From 2018-2022, a total of 73 days of monitoring occurred across
all projects during the seasonal window of June through November.
During this time, 13 sea lions were sighted. Based upon sightings and
monitoring days, we calculated a daily occurrence rate of 0.18 sea
lions per day.
San Francisco has received a record amount of rainfall since July
1, 2022 (Bay City News, 2023), indicating that increased freshwater
inflow into the Bay could be expected this year. The Bay did not
experience similar freshwater inflow during the LWMEP and POWR years of
2018-2022. As the impacts of increased freshwater flow into the project
area on California sea lion occurrences are unclear, and this increased
freshwater input did not occur during prior monitoring years, we
conservatively used a daily occurrence rate of California sea lions,
one sea lion per day, to estimate take.
Harbor porpoise--The harbor porpoise population has been growing
over time in the Bay (Stern et al., 2017). Although commonly sighted in
the vicinity of Angel Island and the Golden Gate Bridge, approximately
6 and 12 kilometers (3.7 and 7.5 miles, respectively) southwest of the
Wharf, individuals may use other areas of central the Bay (Keener,
2011), as well as the project area. As limited data is available on the
occurrences of harbor porpoises in the Bay, NMFS used PSO monitoring
data from previous stages of the LWMEP (AECOM, 2019, 2020, 2021) and
Year 1 of the Point Orient Wharf Removal (POWR) project (AECOM, 2022)
to generate a daily occurrence rate. NMFS calculated the daily
occurrence rate according to the same methods for calculating the daily
occurrence rate for California sea lions, as described above. From
2018-2022, a total of 16 harbor porpoises were sighted on 73 monitoring
days, resulting in a daily occurrence rate of 0.22 harbor porpoises per
day. Due to the impacts of increased freshwater inflow into the Bay
(Bay City News, 2023) resulting from elevated rainfall being unclear,
we conservatively used a higher daily occurrence rate of harbor
porpoises, one porpoise per day, to estimate take.
Gray whale--Gray whales are often sighted in the Bay during
February and March, however, pile driving activities are not planned to
occur during this time. Prior monitoring reports for similar projects
occurring during the same work windows did not document gray whales in
the area (AECOM, 2019,
[[Page 31710]]
2020, 2021). Limited sightings of gray whales in the Bay include
strandings (Bartlett, 2022; TMMC, 2019) and whale watch reports
(Bartlett, 2022). At-sea densities and regular observational data for
gray whales in the Bay during the planned project time are not
available. Although unlikely during the time planned for in-water
construction activities, Chevron conservatively estimated that up to
two gray whales may occur in the project area.
Bottlenose dolphin--The numbers of dolphins in the Bay have been
increasing over the years (Perlman, 2017; Szczepaniak et al., 2013),
and a recent study determined that bottlenose dolphins have expanded
their range to include coastal waters north and south of the Bay
(Keener et al., 2023). In the Bay, dolphins have been sighted in the
vicinity of the Golden Gate Bridge, around Yerba Buena and Angel
Islands, and in the central Bay as far east as Alameda and Point
Richard (Keener et al., 2023). Although dolphins may occur in the Bay
year-round, occurrence estimates are limited. Chevron estimated that
one group of dolphins may enter the Bay once per month. Weller et al.
(2016) estimated an average group size for coastal bottlenose dolphins
to be approximately 8.2 dolphins.
Northern elephant seal--Small numbers of elephant seals may haul
out or strand within the central Bay (Hern[aacute]ndez, 2020). Previous
monitoring, however, has shown northern elephant seal densities to be
very low in the area and, based upon seasonality of occurrences,
northern elephant seals would be unlikely to occur in the project area
during the project activities. Additionally, northern elephant seals
were not observed during pile driving monitoring for the LWMEP from
2018-2021 (AECOM, 2018, 2019, 2020, 2021) nor for the Point Orient
Wharf Removal in 2022 (AECOM, 2022), which was located just north of
the project area. While it is unlikely that northern elephant seals
would occur in the project area during the months in which work is
planned, Chevron conservatively estimated that 1 northern elephant seal
could enter the project area once every 3 days during in-water
construction activities resulting in a total of 10 northern elephant
seals.
Northern fur seal--The presence of northern fur seals in depends
upon oceanic conditions, as more fur seals are more likely to range in
the Bay in search of food and strand during El Ni[ntilde]o events
(TMMC, 2016). Equatorial sea surface temperatures of the Pacific Ocean
have been below average across most of the Pacific. La Ni[ntilde]a
conditions are likely to remain into the spring of 2023, after which
conditions are expected to become more neutral. However, it is unlikely
El Ni[ntilde]o conditions will develop later in 2023 (NOAA, 2022).
Northern fur seals were not observed during prior LWMEP monitoring
(AECOM, 2019, 2020, 2021) nor during the POWRP monitoring (AECOM,
2022). While it is unlikely that northern fur seals would occur in the
project areas during in-water activities, Chevron conservatively
estimated that a maximum of 10 northern fur seals could occur enter the
project area.
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.
Take estimate calculations vary by species. To calculate take by
Level B harassment for harbor seals, California sea lions, and harbor
porpoises, NMFS multiplied the daily occurrence estimates described in
the Marine Mammal Occurrence section by the number of project days
(Table 7).
For bottlenose dolphins, Chevron estimated, and NMFS concurs, that
one group of eight bottlenose dolphins may be taken by Level B
harassment every month of the project. Therefore, Chevron requested,
and NMFS has authorized, 32 takes of bottlenose dolphins by Level B
harassment.
Chevron based requested take by Level B harassment for gray whales
upon total daily occurrence estimates during the project period.
Chevron conservatively estimated, and NMFS concurs, that two gray
whales may enter the project area per year. Therefore, Chevron
requested, and NMFS has authorized, two takes of gray whales by Level B
harassment (Table 7).
For northern elephant seals, Chevron conservatively estimated, and
NMFS concurs, that one northern elephant seal could enter the project
area once every 3 days during in-water construction activities.
Therefore, Chevron requested, and NMFS has authorized, 10 takes of
northern elephant seals by Level B harassment (Table 7).
Based upon prior occurrences in the Bay, Chevron conservatively
estimated, and NMFS concurs, that a maximum of 10 northern fur seals
could occur in the project area during the in-water construction
activity period. Therefore, Chevron requested, and NMFS has authorized
10 takes of northern fur seals by Level B harassment (Table 7).
Chevron did not request, nor has NMFS authorized, take by Level A
harassment. For all pile driving activities, Chevron will to implement
shutdown zones (described further in the Mitigation section) that are
expected to effectively prevent take by Level A harassment.
Table 7--Authorized Take by Level B Harassment and Estimated Take as a Percentage of the Population
----------------------------------------------------------------------------------------------------------------
Authorized take by level B harassment
------------------------------------------------ Estimated take
Species Expected Vibratory as a
occurrence Impact install install/ Total percentage of
extract population
----------------------------------------------------------------------------------------------------------------
Harbor seal................... 237 seals per 4,977 2,133 7,110 23
day.
Sea lion...................... 1 sea lion per 21 9 30 0.012
day \1\.
Harbor porpoise............... 1 harbor 21 9 30 0.39
porpoise per
day \1\.
Bottlenose dolphin............ Up to 8 dolphins N/A N/A 32 1.77
once per month.
Gray whale.................... 2 whales over N/A N/A 2 0.007
project
duration.
Northern elephant seal........ 1 seal every 3 N/A N/A 10 0.005
days.
Northern fur seal............. 10 seals over N/A N/A 10 0.071
project
duration.
----------------------------------------------------------------------------------------------------------------
\1\ Rounded daily occurrence to one individual per day.
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,
[[Page 31711]]
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 would 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.
Chevron must follow mitigation measures as specified below.
Chevron must ensure that construction supervisors and crews, the
monitoring team, and relevant Chevron staff are trained prior to the
start of all pile driving activities, so that responsibilities,
communication procedures, monitoring protocols, and operational
procedures are clearly understood. New personnel joining during the
project must be trained prior to commencing work.
Shutdown Zones
Chevron must establish shutdown zones for all pile driving
activities. The purpose of a shutdown zone is generally to define an
area within which shutdown of the activity will occur upon sighting of
a marine mammal (or in anticipation of an animal entering the defined
area). Shutdown zones will be based upon the Level A harassment zone
for each pile size/type and driving method where applicable, as shown
in Table 6. A minimum shutdown zone of 10 m will be required for all
in-water construction activities to avoid physical interaction with
marine mammals. For pile driving, the radii of the shutdown zones are
rounded to the next largest 10 m interval in comparison to the Level A
harassment zone for each activity type. If a marine mammal is observed
entering or within a shutdown zone during pile driving activity, the
activity must be stopped until there is visual confirmation that the
animal has left the zone or the animal is not sighted for a period of
15 minutes. Shutdown zones for each activity type are shown in Table 8.
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 PSOs will document the animal's presence
within the estimated harassment zone.
Chevron 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 will be equivalent to the Level B harassment zones for each
activity. If a marine mammal species for which take is not authorized
or a species for which incidental take has been authorized but the
authorized number of takes has been met enters the shutdown zone, all
in-water activities must 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 animal
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 will result in an imminent
safety concern, as determined by Chevron or its designated officials,
the in-water activity will be allowed to continue until the safety
concern has been addressed, and the animal will be continuously
monitored.
Table 8--Shutdown Zones by Activity Type
--------------------------------------------------------------------------------------------------------------------------------------------------------
Shutdown zones (m) \1\
Method Pile type -------------------------------------------------------------------------------
LF MF HF PW OW
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile removal activities:
Vibratory extract..................... 36-inch steel pile.......... 20 10 30 20 10
18-inch concrete pile....... 10 10 10 10 10
Pile installation activities:
Impact install............................ 24-inch square concrete pile 40 10 40 20 10
Vibratory install......................... 36-inch steel pile.......... 20 10 30 20 10
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Observers will monitor as far as the eye can see.
Protected Species Observers
The placement of 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 will 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.
PSOs will monitor the full shutdown zones and the Level B
harassment zones to the extent practicable. Monitoring zones provide
utility for observing by establishing monitoring protocols for areas
adjacent to the shutdown zones. Monitoring zones enable observers to be
aware of and communicate the presence of marine mammals in the project
areas outside the shutdown zones and thus prepare for a potential
cessation of activity should the animal enter the shutdown zone.
Pre-and Post-Activity Monitoring
Monitoring must take place from 30 minutes prior to initiation of
pile driving activities (i.e., pre-clearance monitoring) through 30
minutes post-
[[Page 31712]]
completion of pile driving. 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
a 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.
Bubble Curtain
A bubble curtain must be employed during all impact pile
installation of the 24-inch square concrete piles to interrupt the
acoustic pressure and reduce impact on marine mammals. The bubble
curtain must distribute air bubbles around 100 percent of the piling
circumference for the full depth of the water column. The lowest bubble
ring must be in contact with the mudline for the full circumference of
the ring. The weights attached to the bottom ring must ensure 100
percent substrate contact. No parts of the ring or other objects may
prevent full substrate contact. Air flow to the bubblers must be
balanced around the circumference of the pile.
Based on our evaluation of the applicant's planned 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 would result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present while
conducting the activities. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density);
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the activity; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas);
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors;
<bullet> How anticipated responses to stressors impact either: (1)
long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks;
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat); and,
<bullet> Mitigation and monitoring effectiveness.
Visual Monitoring
Marine mammal monitoring must be conducted in accordance with the
conditions in this section, the Monitoring Plan, and this IHA. Marine
mammal monitoring during pile driving activities will be conducted by
PSO's meeting NMFS' standards and in a manner consistent with the
following:
<bullet> PSOs must be independent of the activity contractor (for
example, employed by a subcontractor) and have no other assigned tasks
during monitoring periods;
<bullet> At least one PSO will have prior experience performing the
duties of a PSO during construction activity pursuant to a NMFS-issued
incidental take authorization;
<bullet> Other PSOs may substitute other relevant experience,
education (degree in biological science or related field), or training
for prior experience performing the duties of a PSO during construction
activity pursuant to a NMFS-issued incidental take authorization;
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator must be designated. The lead
observer must have prior experience performing the duties of a PSO
during construction activity pursuant to a NMFS-issued incidental take
authorization; and
<bullet> PSOs must be approved by NMFS prior to beginning any
activity subject to the IHA.
PSOs should have the following additional qualifications:
<bullet> Ability to conduct field observations and collect data
according to assigned protocols;
<bullet> Experience or training in the field identification of
marine mammals, including the identification of behaviors;
<bullet> Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
<bullet> Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates, times, and reason for implementation
of mitigation (or why mitigation was not implemented when required);
and marine mammal behavior; and
<bullet> Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
Chevron will have at least two PSOs stationed at the best possible
vantage points in the project area to monitor during all pile driving
activities. Monitoring will occur from elevated locations along the
shoreline or on barges where the entire shutdown zones and monitoring
zones are visible. PSOs will be equipped with high quality binoculars
for monitoring and radios or cells phones for maintaining contact
[[Page 31713]]
with work crews. Monitoring will be conducted 30 minutes before,
during, and 30 minutes after all in water construction activities. In
addition, PSOs will record all incidents of marine mammal occurrence,
regardless of distance from activity, and will document any behavioral
reactions in concert with distance from piles being driven or removed.
Pile driving activities include the time to install or remove a single
pile or series of piles, as long as the time elapsed between uses of
the pile driving equipment is no more than 30 minutes.
In addition to monitoring on days that construction will occur, as
planned by the applicant, Chevron will conduct biological monitoring
within 1 week ahead of the project's start date to establish baseline
observation. These observation periods will encompass different tide
levels at different hours of the day.
Data Collection
Chevron will record detailed information about implementation of
shutdowns, counts and behaviors (if possible) of all marine mammal
species observed, times of observations, construction activities that
occurred, any acoustic and visual disturbances, and weather conditions.
PSOs will use approved data forms to record the following information:
<bullet> Date and time that permitted construction activity begins
and ends;
<bullet> Type of pile removal activities that take place;
<bullet> Weather parameters (e.g., percent cloud cover, percent
glare, visibility, air temperature, tide level, Beaufort sea state);
<bullet> Species counts, and, if possible, sex and age classes of
any observed marine mammal species;
<bullet> Marine mammal behavior patterns, including bearing and
direction of travel;
<bullet> Any observed behavioral reactions just prior to, during,
or after construction activities;
<bullet> Location of marine mammal, distance from observer to the
marine mammal, and distance from pile driving activities to marine
mammals;
<bullet> Whether an observation required the implementation of
mitigation measures, including shutdown procedures and the duration of
each shutdown; and
<bullet> Any acoustic or visual disturbances that take place.
Reporting
Chevron must submit a draft marine mammal monitoring report to NMFS
within 90 days after the completion of pile driving activities, or 60
days prior to the requested 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. The marine
mammal report will include an overall description of work completed, a
narrative regarding marine mammal sightings, and associated PSO data
sheets and/or raw sighting data. Specifically, the report will include:
<bullet> Dates and times (begin and end) of all marine mammal
monitoring;
<bullet> 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);
<bullet> PSO locations during marine mammal monitoring; and
<bullet> Environmental conditions during monitoring periods (at
beginning and end of PSO shift and whenever conditions change
significantly), including Beaufort sea state and any other relevant
weather conditions including cloud cover, fog, sun glare, and overall
visibility to the horizon, and estimated observable distance.
For each observation of a marine mammal, the following will be
recorded:
<bullet> Name of PSO who sighted the animal(s) and PSO location and
activity at time of sighting;
<bullet> Time of sighting;
<bullet> 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;
<bullet> Distance and location of each observed marine mammal
relative to pile being driven or removed for each sighting;
<bullet> Estimated number of animals (min/max/best estimate);
<bullet> Estimated number of animals by cohort (adults, juveniles,
neonates, group composition, etc.);
<bullet> 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); and
<bullet> Animal's closest point of approach and estimated time
spent within the harassment zone.
Additionally, Chevron must include the following information in the
report:
<bullet> Number of marine mammals detected within the harassment
zones, by species; and
<bullet> Detailed information about any implementation of any
mitigation triggered (e.g., shutdowns and delays), a description of
specific actions that ensured, and resulting changes in behavior of the
animal(s), if any.
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, Chevron will report the
incident to the Office of Protected Resources (OPR)
(<a href="/cdn-cgi/l/email-protection#3d6d6f1374696d137052535449524f54535a6f584d524f494e7d53525c5c135a524b"><span class="__cf_email__" data-cfemail="1c4c4e3255484c325173727568736e75727b4e796c736e686f5c72737d7d327b736a">[email protected]</span></a>), 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, Chevron
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. Chevron must not resume their activities until notified by
NMFS.
The report will 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> 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 31714]]
determination. In addition to considering estimates of the number of
marine mammals that might be ``taken'' through harassment, NMFS
considers other factors, such as the likely nature of any impacts or
responses (e.g., intensity, duration), the context of any impacts or
responses (e.g., critical reproductive time or location, foraging
impacts affecting energetics), as well as effects on habitat, and the
likely effectiveness of the mitigation. We also assess the number,
intensity, and context of estimated takes by evaluating this
information relative to population status. Consistent with the 1989
preamble for NMFS' implementing regulations (54 FR 40338, September 29,
1989), the impacts from other past and ongoing anthropogenic activities
are incorporated into this analysis via their impacts on the baseline
(e.g., as reflected in the regulatory status of the species, population
size and growth rate where known, ongoing sources of human-caused
mortality, or ambient noise levels).
To avoid repetition, the discussion of our analysis applies to all
the species listed in Table 2, 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
serious injury or mortality is anticipated given the nature of the
activity.
Pile driving 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 from underwater sounds
generated from impact and vibratory pile driving activities. Potential
takes could occur if individuals move into the ensonified zones when
these activities are underway.
The takes by Level B harassment will be due to potential behavioral
disturbance. 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. Further, the amount of take authorized is extremely small when
compared to stock abundance.
No marine mammal stocks for which take 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 pile driving activities begin, and 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 of Level B behavioral harassment. Furthermore, the
pile driving 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 intermittently over the course of 30 days.
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,
increased haul out time by pinnipeds, 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 harassment 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.
As previously described, an Unusual Mortality Event (UME) has been
declared for Eastern Pacific gray whales. However, we do not expect
authorized takes in this action to exacerbate the ongoing UME. As
mentioned previously, no injury or mortality is authorized, and take by
Level B harassment is limited (two takes over the duration of the
project). Therefore, we do not expect the take authorization to
compound the ongoing UME.
The project is not expected to have significant adverse effects on
marine mammal habitat. There are no known Biologically Important Areas
(BIAs) or ESA-designated critical habitat within the project area, and
the activities will not permanently modify existing marine mammal
habitat. Although harbor seal haulout sites are located in the Bay,
hauled out seals are not likely to be impacted. PSOs during the seismic
retrofit of the Richmond Bridge did not note any decline in use by
harbor seals at Castro Rocks, a haulout site which is approximately 20
to 100 m from the bridge (Greene et al., 2006) and 560 m from the
project area. In addition, any pupping that may occur at Castro Rocks
will take place outside of the work window for the pile driving
activities. 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, these factors, as well as the available body of
evidence from other similar activities, demonstrate that the potential
effects of the specified activities will 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 have impacts on annual rates of recruitment or survival.
In summary and as described above, the following factors primarily
support our determination that the impacts resulting from this activity
are not expected to adversely affect any of the species or stocks
through effects on annual rates of recruitment or survival:
<bullet> No serious injury, mortality, or Level A harassment is
anticipated or authorized;
[[Page 31715]]
<bullet> The specified activities and associated ensonified areas
are very small relative to the overall habitat ranges of all species;
<bullet> The project area does not overlap known BIAs or ESA-
designated critical habitat;
<bullet> The lack of anticipated significant or long-term effects
to marine mammal habitat;
<bullet> The presumed efficacy of the mitigation measures in
reducing the effects of the specified activity; and
<bullet> Monitoring reports from similar work in the 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 will have a negligible impact on all affected marine mammal
species or stocks.
Small Numbers
As noted previously, only take of small numbers of marine mammals
may be authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one-third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
The amount of take NMFS has authorized is below one-third of the
estimated stock abundances for all seven stocks (refer back to Table
8). For most stocks, the authorized take of individuals is less than 2
percent of the abundance of the affected stock (with exception of
harbor seals at 23 percent). This is likely a conservative estimate
because it assumes all takes are of different individual animals, which
is likely not the case for harbor seals, given the nearby haulout. 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 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 proposed 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 Chevron for the potential harassment of
small numbers of seven marine mammal species incidental to the LWMEP in
San Francisco Bay, California, provided the previously mentioned
mitigation, monitoring, and reporting requirements are followed.
Dated: May 15, 2023.
Shannon Bettridge,
Chief, Marine Mammal and Sea Turtle Conservation Division, Office of
Protected Resources, National Marine Fisheries Service.
[FR Doc. 2023-10623 Filed 5-17-23; 8:45 am]
BILLING CODE 3510-22-P
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