Notice2024-01790
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Pacific Gas & Electric Sediment Remediation Project, San Francisco Bay
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
January 30, 2024
Effective
May 1, 2024
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
In accordance with the regulations implementing the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that NMFS has issued an incidental harassment authorization (IHA) to Pacific Gas & Electric (PG&E) to incidentally harass marine mammals during construction activities associated with a sediment remediation project in San Francisco Bay.
Full Text
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<title>Federal Register, Volume 89 Issue 20 (Tuesday, January 30, 2024)</title>
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[Federal Register Volume 89, Number 20 (Tuesday, January 30, 2024)]
[Notices]
[Pages 5865-5877]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2024-01790]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XD639]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Pacific Gas & Electric Sediment
Remediation Project, San Francisco Bay
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
Pacific Gas & Electric (PG&E) to incidentally harass marine mammals
during construction activities associated with a sediment remediation
project in San Francisco Bay.
DATES: The authorization is effective from May 1, 2024 to April 30,
2025.
ADDRESSES: Electronic copies of the application and supporting
documents, as well as a list of the references cited in this document,
may be obtained online at: <a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-pacific-gas-electric-sediment-remediation-project-san">https://www.fisheries.noaa.gov/action/incidental-take-authorization-pacific-gas-electric-sediment-remediation-project-san</a>. In case of problems accessing these documents,
please call the contact listed below.
FOR FURTHER INFORMATION CONTACT: Kristy Jacobus, Office of Protected
Resources, NMFS, (301) 427-8401.
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 May 4, 2023, NMFS received a request from PG&E for an IHA to
take marine mammals incidental to a Sediment Remediation Project in
Remedial Response Areas A and B, Piers
[[Page 5866]]
39 to 43\1/2\, San Francisco Bay. Following NMFS' review of the
application, PG&E submitted additional information on July 25, 2023 and
September 26, 2023 and subsequently submitted a revised application on
November 16, 2023, which was deemed adequate and complete. PG&E's
request is for take of seven species (eight stocks) of marine mammals
by Level B harassment only. Neither PG&E nor NMFS expect serious injury
or mortality to result from this activity and, therefore, an IHA is
appropriate. There are no changes from the proposed IHA to the final
IHA.
This IHA will cover 1 year of a larger project for which PG&E
intends to request take authorization for subsequent facets of the
project if necessary. The larger 5 to 7 year project involves
construction to remediate contaminated sediment.
Description of Activity
Overview
PG&E is remediating sediments impacted with polycyclic aromatic
hydrocarbons (PAHs) in San Francisco Bay around the area offshore of
Pier 43\1/2\ to the east of Pier 45 and offshore area of Pier 43. The
Project is expected to occur over a period of 5 to 7 years, and this
IHA will authorize take associated with Year 1 only. PG&E expects that
Year 1 will include installation of hydroacoustic data collection
piles; installation of piles to attach a turbidity curtain; dredging of
impacted sediment; installation of sediment pins to promote slope
stability; capping of impacted sediment to be left in place; placement
of armoring as needed; and temporary relocation of the Red and White
Fleet (RWF). The project's planned activities that have the potential
to take marine mammals, by Level B only, include impact installation
and vibratory removal of composite piles; vibratory installation and
removal of H-piles or steel shell piles less than or equal to 24 inches
(61 cm) in diameter; vibratory installation and removal of 36-inch
steel guide piles; vibratory and impact installation of 24-inch steel
fender piles; vibratory removal of the 24-inch fender piles; and
vibratory and impact installation of timber piles. In-water
construction is expected to occur over 50 non-consecutive days over 1
year.
A detailed description of the planned construction project is
provided in the Federal Register noticed for the proposed IHA (88 FR
82836, November 27, 2023). 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.
Comments and Responses
A notice of NMFS' proposal to issue an IHA to PG&E was published in
the Federal Register on November 27, 2023 (88 FR 82836). That notice
described, in detail, PG&E'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 received comments
from Turtle Island Restoration Network (TIRN) and a letter from the
U.S. Geological Survey stating that they had no comments. In addition,
a comment was received from a private citizen expressing general
opposition to PG&E, which is not related to NMFS' proposed action. All
relevant, substantive comments, and NMFS' responses, are provided
below. The comments and recommendations are available online at:
<a href="https://www.fisheries.noaa.gov/action/incidental-take-authorization-pacific-gas-electric-sediment-remediation-project-san">https://www.fisheries.noaa.gov/action/incidental-take-authorization-pacific-gas-electric-sediment-remediation-project-san</a>. Please see the
comment submission for full details regarding the recommendations and
supporting rationale.
Comment 1: TIRN asserts that NMFS failed to adequately consider the
potential for delayed mortality of marine mammals or the potential
long-term impacts of underwater noise on the ecosystem as a whole, and
states that NMFS ``must require PG&E to submit a request for
authorization of incidental Level A harassment takes of marine
mammals.''
Response: We first note that TIRN conflates take by Level A
harassment and mortality and serious injury. As defined by the MMPA,
Level A harassment means ``any act of pursuit, torment, or annoyance
which has the potential to injure a marine mammal or marine mammal
stock in the wild'' (16 U.S.C. 1362(18)(A)). Serious injury is defined
as ``any injury that will likely result in mortality'' under NMFS' MMPA
implementing regulations (50 CFR 216.3). Level A harassment does not
include serious injury or mortality, and serious injury or mortality
cannot be authorized through an IHA.
NMFS acknowledges that pile driving can impact marine mammals'
ability to detect prey and can impact marine mammal prey in the
vicinity of the project area, as discussed in the Federal Register
notice for the proposed IHA (88 FR 82836, November 27, 2023). However,
NMFS expects these effects to be temporary and disagrees that these
impacts are likely to result in long-term disruption or result in
delayed mortality. TIRN suggests, without evidence, that the specified
activity is likely to reduce the ability for marine mammals to hunt to
the extent that such behavioral effects may lead to delayed mortality.
Any effects to marine mammals' ability to hunt or detect prey are
expected to be temporary, e.g., on the order of minutes to hours, due
to marine mammals' transient nature, likelihood to avoid disturbance,
the short duration of construction, and the mitigation used which will
reduce marine mammals' exposure to pile driving noise. Mortality can
result if marine mammal foraging behavior is impeded, but such an
extreme result would require complete cessation of foraging over an
extended period of time. There is no potential for such impacts to
result from this activity given the short durations over which bouts of
activity will occur and unimpeded access to other areas of equal
foraging value. The most likely impact to fishes from pile driving are
expected to be temporary behavioral avoidance, and any behavioral
avoidance by fish of the disturbed area would still leave significantly
large potential areas in the nearby vicinity for marine mammals to
forage. Further discussion of the expected short-term impacts to marine
mammals and prey can be found in the Potential Effects of Specified
Activities on Marine Mammals and Their Habitat in the Federal Register
notice for the proposed IHA (88 FR 82836, November 27, 2023).
NMFS disagrees that long-term disruptions and delayed mortality of
marine mammals are likely to occur as a result of PG&E's project and,
therefore, authorization of Level A harassment or serious injury or
mortality is not appropriate.
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'
[[Page 5867]]
Stock Assessment Reports (SARs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and
more general information about these species (e.g., physical and
behavioral descriptions) may be found on NMFS' 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 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 and Alaska SARs. All values presented in table 1 are
the most recent available at the time of publication and are available
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>.
Table 1--Marine Mammal Species Likely Impacted by the Specified Activities \1\
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ESA/MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\2\ abundance survey) \3\ SI \4\
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Family Delphinidae:
Bottlenose dolphin.............. Tursiops truncatus..... Coastal California..... -,-,N 453 (0.06, 346, 2011). 2.7 >=2.0
Family Phocoenidae (porpoises):
Harbor porpoise................. Phocoena phocoena...... San Francisco-Russian -,-,N 7,777 (0.62, 4811, 73 >=0.4
River. 2017).
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Order Carnivora--Pinnipedia
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Family Otariidae (eared seals and
sea lions):
California Sea Lion............. Zalophus californianus. United States.......... -,-,N 257,606 (N/A, 233,515, 14,011 >=321
2014).
Northern Fur Seal............... Callorhinus ursinus.... California............. -,-,N 14,050 (0.03, 7,524, 451 1.8
2013).
Northern Fur Seal............... Callorhinus ursinus.... Eastern North Pacific.. -, D, Y 626,618 (0.2, 530,376, 11,403 373
2021).
Steller Sea Lion................ Eumetopias jubatus..... Eastern North Pacific.. -,-,N 43,201 (N/A, 43,201, 2,592 112
2017).
Family Phocidae (earless seals):
Harbor Seal..................... Phoca vitulina......... California............. -,-,N 30,968 (N/A, 27,348, 1,641 43
2014).
Northern Elephant Seal.......... Mirounga angustirostris California Breeding.... -,-,N 187,386 (N/A, 85,369, 5,122 13.7
2013).
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\1\ 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)).
\2\ 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.
\3\ NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</a>. CV is coefficient of variation; Nmin is the minimum estimate of stock abundance.
\4\ 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, vessel strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range.
As indicated above, all seven species (with eight managed stocks)
in table 1 temporally and spatially co-occur with the activity to the
degree that take is reasonably likely to occur. Gray whales and
humpback whales rarely enter the Bay but may occasionally pass offshore
of the Project Area. However, if either of these species are to
approach the Level B harassment zone construction will be shutdown.
Therefore, no take is expected of these species, and these species will
not be discussed further.
A detailed description of the of the species likely to be affected
by the sediment remediation 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 (88 FR 82836, November 27, 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
[[Page 5868]]
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 (dolphins, 150 Hz to 160 kHz.
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) (true 50 Hz to 86 kHz.
seals).
Otariid pinnipeds (OW) (underwater) (sea 60 Hz to 39 kHz.
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 PG&E's sediment remediation
activities have the potential to result in behavioral harassment of
marine mammals in the vicinity of the project area. The notice of
proposed IHA (88 FR 82836, November 27, 2023) included a discussion of
the effects of anthropogenic noise on marine mammals and the potential
effects of underwater noise from PG&E's construction on marine mammals
and their habitat. That information and analysis is incorporated by
reference into this final IHA determination and is not repeated here;
please refer to the notice of proposed IHA (88 FR 82836, November 27,
2023).
Estimated Take of Marine Mammals
This section provides an estimate of the number of incidental takes
authorized through the IHA, which will inform 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 and/or temporary threshold shift
(TTS) for individual marine mammals resulting from exposure to
vibratory and impact pile driving. Based on the nature of the activity
and the anticipated effectiveness of the mitigation measures (i.e.,
shutdown) 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.
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 [micro]Pa)) for continuous (e.g., vibratory pile
driving, drilling) and above RMS SPL 160 dB re 1 [micro]Pa for non-
explosive impulsive (e.g., seismic
[[Page 5869]]
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 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.
PG&E's activity includes 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 [micro]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). PG&E's
activity includes the use of impulsive (impact pile driving) and non-
impulsive (vibratory pile driving) 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="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance</a>.
Table 3--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
PTS onset acoustic thresholds * (received level)
Hearing group ------------------------------------------------------------------------
Impulsive Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans........... Cell 1: Lpk,flat: 219 dB; Cell 2: LE,LF,24h: 199 dB.
LE,LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans........... Cell 3: Lpk,flat: 230 dB; Cell 4: LE,MF,24h: 198 dB.
LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans.......... Cell 5: Lpk,flat: 202 dB; Cell 6: LE,HF,24h: 173 dB.
LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW) (Underwater)..... Cell 7: Lpk,flat: 218 dB; Cell 8: LE,PW,24h: 201 dB.
LE,PW,24h: 185 dB.
Otariid Pinnipeds (OW) (Underwater).... Cell 9: Lpk,flat: 232 dB; Cell 10: LE,OW,24h: 219 dB.
LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
it is valuable for action proponents to indicate the conditions under which these acoustic thresholds 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 via sound generated by the primary
components of the project (i.e., pile driving and removal).
The project includes vibratory pile installation and removal and
impact pile driving. Source levels for these activities are based on
reviews of measurements of the same or similar types and dimensions of
piles available in the literature. Source levels for each pile size and
activity are presented in table 4. Source levels for vibratory
installation and removal of piles of the same diameter are
conservatively assumed to be the same.
The majority of source levels were selected from a single source,
as shown in table 4 below. For the vibratory installation of 36-inch
steel shell piles and vibratory installation of timber piles, NMFS
determined it appropriate to use an average of source levels. NMFS
reviewed all available monitoring reports of vibratory driving of 36-
inch steel piles in San Francisco Bay (Gast &Associated Environmental
Consultants, 2021, 2023; Illingworth & Rodkin, 2018, 2020). Averaging
of sound levels was performed by first converting from dB to linear
units of pressure (Pascals [Pa]), averaging, and converting back to dB.
The mean RMS level at 10 meters (m) for San Francisco Bay was
approximately 168 dB re 1 [micro]Pa RMS. Therefore, NMFS has selected
this average value as the most appropriate value for vibratory driving
of 36-inch steel pipe piles during the project. With regard to
vibratory installation of timber piles, there are limited data
available, and none from San Francisco Bay. Therefore, NMFS evaluated
all available timber pile data (three projects from Puget Sound, WA,
and one project from Norfolk, VA) (Greenbusch Group, 2018; Illingworth
and Rodkin, 2017; Laughlin, 2011; U.S. Navy, 2016) and calculated the
mean and maximum RMS values for each project and for all projects
together. The overall mean RMS value was approximately 158 dB re 1
[micro]Pa RMS. NMFS therefore selected this as an appropriate proxy
value for vibratory driving of timber piles during the project.
Table 4--Sound Source Levels for Pile Driving Activities \1\
----------------------------------------------------------------------------------------------------------------
Peak sound
pressure (dB RMS (dB re 1 SEL (dB re 1
Pile type Method re 1 [micro]Pa) [micro]Pa2 Source
[micro]Pa) sec)
----------------------------------------------------------------------------------------------------------------
Hydroacoustic Data Collection
----------------------------------------------------------------------------------------------------------------
18-inch composite/plastic.... Impact Install.. 185 160 150 Caltrans, 2020;
extrapolated
from 13-inch
composite.
[[Page 5870]]
18-inch composite/plastic.... Vibratory N/A 152 N/A WSDOT, 2012; 13-
Removal. inch composite
used as proxy.
----------------------------------------------------------------------------------------------------------------
Turbidity Curtain
----------------------------------------------------------------------------------------------------------------
Steel H-Pile................. Vibratory N/A 143 N/A Caltrans, 2020.
Install and
Removal.
Steel Shell Pile <=24-inches. Vibratory N/A 153 N/A Caltrans, 2020;
Install and 24-inch pipe
Removal. pile used as
proxy.
----------------------------------------------------------------------------------------------------------------
RWF Relocation
----------------------------------------------------------------------------------------------------------------
24-inch steel shell.......... Vibratory N/A 153 N/A Caltrans, 2020.
Installation
and Removal.
24-inch steel shell.......... Impact 208 193 178 Illingworth &
Installation Rodkin, Inc.
\2\. 2014.
36-inch steel shell.......... Vibratory N/A 168 N/A Gast &
Installation Associated
and Removal. Environmental
Consultants,
2021, 2023;
Illingworth
and Rodkin,
2018, 2020.
See
explanation
above.
----------------------------------------------------------------------------------------------------------------
Slope Stabilization
----------------------------------------------------------------------------------------------------------------
14 to 16 inch Timber......... Vibratory....... N/A 158 N/A Greenbusch
Group, 2018;
Illingworth
and Rodkin,
2017;
Laughlin,
2011; U.S.
Navy 2016. See
explanation
above.
14 to 16 inch Timber......... Impact.......... 184 157 145 Caltrans, 2020.
14 to 16-inch Composite...... Vibratory....... N/A 152 N/A WSDOT, 2012. 13-
inch composite
used as proxy.
14 to 16-inch Composite...... Impact.......... 177 153 145 Caltrans, 2020.
----------------------------------------------------------------------------------------------------------------
\1\ All values are at 10 m from the source.
\2\ PG&E will use a bubble curtain attenuation system for impact pile driving of the RWF 24-inch steel shell
piles, and we conservatively assumes a 5 dB reduction in source level from those presented here due to use of
the attenuation system.
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 all impact and vibratory installation and removal of
piles with the exception of vibratory installation and removal of the
36-inch steel pipe piles in the RWF Relocation. Illingworth & Rodkin
conducted hydro-acoustic monitoring for the 2017 WETA Downtown San
Francisco Ferry Terminal Expansion Project and calculated a TL
coefficient of 18.7 for vibratory installation of 36-inch steel shell
piles (Illingworth & Rodkin, 2018). Given the proximity to the project
area, PG&E determined that 18.7 was an appropriate transmission
coefficient to use for the vibratory installation of the 36-inch steel
shell pile, and NMFS concurs.
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 driving, 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. Source levels are provided above in table 4. Inputs used in
the optional User Spreadsheet tool are provided below in table 5.
Resulting estimated Level A and B harassment isopleths are provided in
table 6.
Table 5--User Spreadsheet Inputs (Source Levels Provided in Table 4)
----------------------------------------------------------------------------------------------------------------
Pile type Method Duration Piles/day
----------------------------------------------------------------------------------------------------------------
Hydroacoustic Data Collection
----------------------------------------------------------------------------------------------------------------
18-inch composite/plastic............... Impact Install............ 400 strikes/pile.......... 10
18-inch composite/plastic............... Vibratory Removal......... 20 minutes................ 10
----------------------------------------------------------------------------------------------------------------
[[Page 5871]]
Turbidity Curtain
----------------------------------------------------------------------------------------------------------------
Steel H-Pile............................ Vibratory................. 10 minutes................ 4
Steel Shell Pile <=24-inches............ Vibratory................. 10 minutes................ 4
----------------------------------------------------------------------------------------------------------------
RWF Relocation
----------------------------------------------------------------------------------------------------------------
24-inch steel shell..................... Vibratory................. 10 minutes................ 4
24-inch steel shell..................... Impact.................... 400 strikes/pile.......... 4
36-inch steel shell..................... Vibratory................. 20 minutes................ 4
----------------------------------------------------------------------------------------------------------------
Sediment Pin Installation
----------------------------------------------------------------------------------------------------------------
Timber.................................. Vibratory................. 20 minutes................ 20
Timber.................................. Impact.................... 400 strikes/pile.......... 20
14 to16-inch Composite.................. Vibratory................. 20 minutes................ 10
14 to 16-inch Composite................. Impact.................... 400 strikes/pile.......... 10
----------------------------------------------------------------------------------------------------------------
Table 6--Level A Harassment and Level B Harassment Isopleths From Vibratory and Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
Level A/PTS isopleth (m)
------------------------------------------------------------
Hearing groups Level B Level B area
Pile type & method ------------------------------------------------------------ Isopleth of
Cetaceans Pinnipeds (m) ensonification
------------------------------------------------------------ (km\2\)
LF MF HF Phocids Otariids
--------------------------------------------------------------------------------------------------------------------------------------------------------
Hydroacoustic Data Collection Piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
18-inch composite (Impact)...................................... 16 <1 19 9 <1 10 <0.01
18-inch Composite (Vibratory)................................... 4 <1 6 3 <1 1,360 3.58
--------------------------------------------------------------------------------------------------------------------------------------------------------
Turbidity Curtain
--------------------------------------------------------------------------------------------------------------------------------------------------------
Steel H-Pile (Vibratory)........................................ <1 0 <1 <1 <1 341 0.29
Steel Shell Pile <= 24-inches (Vibratory)....................... 2 <1 4 2 <1 1,585 4.61
--------------------------------------------------------------------------------------------------------------------------------------------------------
RWF Temporary Relocation Piles
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch Steel Shell Pile (Vibratory)............................ 2 <1 4 2 <1 1,585 4.54
24-inch Steel Shell Pile (Impact, Attenuated)*.................. 294 11 351 158 12 736 1.06
36-inch Steel Shell Pile (Vibratory)............................ 20 3 28 14 2 3,688 23.46
--------------------------------------------------------------------------------------------------------------------------------------------------------
Sediment Pins
--------------------------------------------------------------------------------------------------------------------------------------------------------
14 to 16-inch Timber Pile (Vibratory)........................... 16 2 23 10 1 3,415 19.17
14 to 16-inch Timber Pile (Impact).............................. 12 <1 14 6 <1 6 <0.01
14 to 16-inch Composite Pile (Vibratory)........................ 4 <1 6 3 <1 1,360 3.2
14 to 16-Inch Composite Pile (Impact)........................... 7 <1 9 4 <1 3.4 <0.01
--------------------------------------------------------------------------------------------------------------------------------------------------------
* 5 dB reduction in sound due to use of bubble curtain assumed.
Marine Mammal Occurrence
In this section we provide information about the occurrence of
marine mammals, including density or other relevant information which
will inform the take calculations.
Because reliable marine mammal density information is not available
for the San Francisco Bay, several datasets were used to attain
estimates of the abundance of marine mammals in the Bay. Datasets used
included 5 years of sighting and stranding data from The Marine Mammal
Center (TMMC) (NMFS, 2021a); 5 years of sighting and stranding data
from the California Academy of Sciences (CAS) (NMFS, 2021b); citizen-
reported live sightings from <a href="http://iNaturalist.org">iNaturalist.org</a>; 5 days of sighting data
during sediment investigation in 2020 during the initial phase of the
project (Haase, 2021); and counts from haulouts. Data from all sources,
when available, were considered. Depending on the distribution of
sightings and granularity of data, different sources have been used to
estimate the number of individuals of each species with the potential
to occur in vicinity of the project. The largest ensonified area is
during vibratory installation of 36-inch steel shell piles, which
results in a 3,688 m isopleth and 23.46 kilometers squared (km\2\) area
of ensonification.
Harbor Seal
Harbor seals in the Bay forage mainly within 7.0 miles (mi; (11.3
km)) of their primary haulout site (Grigg et al. 2012), and often
within just 1 to 3 miles (1 to 5 km) (Torok, 1994). The only harbor
seal haulout within 7 miles (11.3 km) of the project site is Yerba
Buena Island (YBI), which is 3.1 mi (5 km) to the east of the Project
Area. Noise from the project is not expected to reach the haulout,
however, harbor seals that use this haulout are likely to forage within
ensonified areas from the project. Harbor seal take estimates were
based on observations conducted by Marine Mammal Observers (MMOs) over
a 5 day period in 2020, during sediment investigation in the initial
phase of the project, within remedial response areas A, B, and C (See
Haase, 2021). A maximum of 20 harbor seals were observed per day. PG&E
therefore estimates 20 harbor seals per day within
[[Page 5872]]
the project area per day. NMFS concurs with this assumption.
Northern Elephant Seal
TMMC recorded 903 elephant seals in the Bay from 2016 to 2021
(NMFS, 2021a). The CAS reported an additional 6 for a total of 909 over
5 years in the Bay from 2016 to 2021 (NMFS, 2021b), yielding an average
of 0.5 elephant seals per day. To ensure sufficient authorization of
take of northern elephant seals, PG&E assumed 0.5 elephant seals will
occur in the area per day (i.e., one elephant seal every 2 days). NMFS
concurs with this assumption.
California Sea Lion
The Pier 39 K-Dock haulout is the only regularly used California
Sea Lion haulout in the vicinity of the Project Area, adjacent to Area
C. The Sea Lion Center at Pier 39 regularly counted the sea lions at K-
Dock from 1991 through 2018. From 2016 through 2018, the yearly average
ranged from 89 to 229 animals per day. The average per day over all 3
years was 191 sea lions (Pacific Gas & Electric, 2023). Although there
are times of the year when the K-dock is unoccupied or there are few
individuals present, it is difficult to predict abundance based on time
of year. In order to ensure sufficient authorization of sea lions, PG&E
is assuming a local abundance estimate of 191 sea lions per day within
the estimated harassment area, and NMFS concurs.
Northern Fur Seal
TMMC recorded 44 northern fur seals in the Bay from 2016 to 2021
(NMFS, 2021a). CAS recorded an additional 3 for a total of 47 over 5
years (NMFS, 2021b), yielding 0.03 per day, or approximately 10 per
year. In the fall and winter, northern fur seals occasionally strand on
YBI and Treasure Island (Pacific Gas & Electric, 2023), approximately
2.0 mi (3.2 km) from the project area. Using PG&E's assumption of
approximately 0.03 fur seals per day over the course of 50 days of pile
driving plus known fur seal strandings near the project area, NMFS has
determined it appropriate to assume five fur seals in the project area
during the project time period.
Steller Sea Lion
Steller sea lions are rare in San Francisco Bay. TMMC recorded four
Steller sea lions in the Bay from 2016 to 2021 (NMFS, 2021a), while CAS
reported no Steller sea lions during this time (NMFS, 2021b). In 2020
and 2021, INaturalist.org recorded four Steller sea lions in the Bay.
On rare occasions, Steller sea lions are seen on the Pier 39 K-dock
haulout. An adult male was spotted there in May 2023 (Segura, 2023) and
in previous years a single male Steller sea lion had been observed
using the Pier 39 K-dock haulout intermittently during July and August
and occasionally September (Pacific Gas & Electric, 2023). Given these
known occasional occurrences of the Steller sea lion at Pier 39, PG&E
feels it is appropriate to assume five Steller sea lions in the project
area during the time period of the project, and NMFS concurs.
Bottlenose Dolphins
Historically, observations of bottlenose dolphins have occurred
west of Treasure Island and were concentrated in the Project vicinity
along the nearshore area of San Francisco south to Redwood City. Since
2016, one individual has been regularly seen near the former Alameda
Air Station and five animals were regularly seen in the summer and fall
of 2018 in the same location (Pacific Gas & Electric, 2023). A recent
study reports that dolphins have been sighted in the vicinity of the
Golden Gate Bridge, around Yerba Buena and Angel Islands, and in the
central Bay (Keener et al., 2023). PG&E is assuming that one group of
bottlenose dolphins will enter into the project isopleth per month of
pile driving, and NMFS concurs. A group size is estimated to be five
animals based on sightings of bottlenose dolphins in the Bay (Pacific
Gas & Electric, 2023).
Harbor Porpoise
Harbor porpoises are primarily seen near the Golden Gate Bridge,
Marin County, and the city of San Francisco on the northwest side of
the Bay (Keener et al., 2012; Stern et al., 2017), in the vicinity of
the project area. Limited data exists on the abundance of harbor
porpoises in the Bay, and therefore data from MMOs in 2020 was used
(see Haase 2021). An individual harbor porpoise was seen in the project
zone on 2 of the 5 days, and a group of two individuals was reported on
a separate day of the 5 day observation period (Haase, 2021). To ensure
sufficient authorization of take of harbor porpoise, it is estimated
that two harbor porpoises will occur within the estimated harassment
area per day.
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 and is authorized.
Take estimate calculations vary by species. To calculate take by
Level B harassment for harbor seals, California sea lions, northern
elephant seals, 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 northern fur seals, PG&E is assuming a total of five animals in
the area of the project during the duration of the project, based on
sightings in the Bay and known strandings on YBI (see Marine Mammal
Occurrence above), and is therefore requesting, and NMFS has
authorized, take of five northern fur seals by Level B harassment
(table 7).
Although Steller sea lions are rare in San Francisco Bay, based on
sighting data and known occurrence of Steller sea lions on the Pier 39
K-dock haulout (PG&E, 2023; Segura, 2023), PG&E is conservatively
requesting five takes by Level B harassment of Steller sea lions during
the time period of the project, and NMFS concurs (table 7).
For bottlenose dolphins, PG&E estimates that one group of five
bottlenose dolphins may be taken by Level B harassment per month of
pile driving. Based on 5 months of pile driving, NMFS has authorized 25
takes by Level B harassment of bottlenose dolphins.
Table 7--Authorized Take by Level B Harassment Authorized and Estimated Take as a Percentage of the Population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Estimated Level B
Species Stock Expected occurrence take Stock abundance * Percent of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific Harbor Seal.................... California................ 20 seals per day.......... 1000 30,968 3.2
Northern Elephant Seal................. California Breeding....... 0.5 seals per day......... 25 187,386 0.01
California Sea Lion.................... United States............. 191 sea lions per day..... 9,550 257,606 3.7
[[Page 5873]]
Northern Fur Seal...................... California; Eastern North 5 seals over project 5 14,050; 626,618 0.04; 0.001
Pacific. duration.
Steller sea lion....................... Eastern United States..... 5 sea lions over project 5 43,201 0.01
duration.
Bottlenose dolphin..................... Coastal California........ 5 dolphins per month of 25 453 5.5
project.
Harbor Porpoise........................ San Francisco-Russian 2 porpoises per day....... 100 7,777 1.3
River.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* NMFS marine mammal stock assessment reports online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessment-reports</a> reports.
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.
PG&E must follow mitigation measures as specified below.
PG&E must ensure that construction supervisors and crews, the
monitoring team, and relevant PG&E 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
PG&E must establish shutdown zones and Level B monitoring 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 animal (or in anticipation of an animal
entering the defined area). Shutdown zones are based on the largest
Level A harassment zone for each pile size/type and driving method, and
behavioral monitoring zones are meant to encompass Level B harassment
zones for each pile size/type and driving method, 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, and the radii of the shutdown zones are rounded to the next
largest 10 m interval in comparison to the Level zone for each activity
type. Marine mammal monitoring will be conducted during all pile
driving activities to ensure that marine mammals do not enter Level A
shutdown zones, that marine mammal presence in the isopleth does not
exceed authorized take, and to prevent take of the humpback and gray
whale. Shutdown zones for each activity type are shown in table 8.
Prior to pile driving, shutdown zones and monitoring zones will be
established based on zones represented in table 8. Observers will
survey the shutdown zones for at least 30 minutes before pile driving
activities start. If marine mammals are found within the shutdown zone,
pile driving will be delayed until the animal has moved out of the
shutdown zone, either verified by an observer or by waiting until 15
minutes has elapsed without a sighting. If a marine mammal approaches
or enters the shutdown zone during pile driving, the activity will be
halted. Pile driving may resume after the animal has moved out of and
is moving away from the shutdown zone or after at least 15 minutes has
passed since the last observation of the animal.
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.
If a species for which authorization has not been granted (i.e.,
gray whale or humpback whale), or a species which has been granted but
the authorized takes are met, is observed approaching or within the
Level B monitoring zone, pile driving activities will be shutdown
immediately. Activities will not resume until the animal has been
confirmed to have left the area or 15 minutes has elapsed with no
sighting of the animal.
[[Page 5874]]
Table 8--Shutdown Zones and Level B Monitoring Zones by Activity
------------------------------------------------------------------------
Shutdown zone for Monitoring zone
Pile type and method all species (m) (m)
------------------------------------------------------------------------
Hydroacoustic Data Collection Piles
------------------------------------------------------------------------
18-inch Composite/Plastic (impact) 20 10
18-Inch Composite/Plastic 10 1,360
(vibratory removal)..............
------------------------------------------------------------------------
Turbidity Curtain
------------------------------------------------------------------------
Steel H-Pile (Vibratory Install 10 341
and Removal).....................
24-inch steel shell pile 10 1,585
(Vibratory install and removal)..
------------------------------------------------------------------------
RWF Relocation Piles
------------------------------------------------------------------------
24-inch steel shell pile 10 1,585
(Vibratory install and removal)..
24-inch steel shell pile (impact- 360 736
attenuated)......................
36-inch steel shell pile 30 3,688
(vibratory)......................
------------------------------------------------------------------------
Sediment Pins
------------------------------------------------------------------------
14 to 16-inch timber (Vibratory).. 30 3,415
14 to 16-inch timber (impact)..... 20 10
14 to 16-inch composite (impact).. 10 10
14 to 16-inch composite (vibratory 20 1,360
install).........................
------------------------------------------------------------------------
Protected Species Observers (PSOs)
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 as much of the Level
B harassment zones as possible. 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-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, 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 are used to 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 steel piles less than 24 inches in diameter to
interrupt the acoustic pressure and reduce impact on marine mammals.
Impact pile driving will not be allowed for 36-inch steel shell piles.
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 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
[[Page 5875]]
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 and the 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 education (degree in biological
science or related field) or training for experience;
<bullet> Where a team of three or more PSOs is required, a lead
observer or monitoring coordinator will be designated. The lead
observer will be required to have prior experience working as a marine
mammal observer during construction;
<bullet> PSOs will submit PSO resumes for approval by NMFS 30 days
prior to the onset of pile driving; 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.
PG&E will have between one and three PSOs on site at all times
during pile driving activities. One PSO will be designated as the Lead
PSO and will receive updates from other PSOs. The Lead PSO will be
stationed at the active pile driving rig or at the best vantage point
practicable to monitor the shutdown zones and implement shutdown and
delay procedures. The other PSOs will be stationed at the best vantage
points practicable to observe the monitoring zones. Exact locations
will be determined in the field based on the pile driving site, field
conditions, and in coordination with contractors, but may include
docks, barges, and tower structures. PSOs will be equipped with high
quality binoculars or spotting scopes for monitoring and radios and
cell phones for maintaining contact with other observers and work crew.
Monitoring will be conducted 30 minutes before, during, and 30 minutes
after all in-water construction activities. 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.
Data Collection
PSOs will use approved data forms to record the following
information:
<bullet> Dates and times (beginning and end) of all marine mammal
monitoring;
<bullet> PSO locations during marine mammal monitoring;
<bullet> Construction activities occurring during each daily
observation period, including how many and what type of piles were
driven or removed and by what method (i.e., impact or vibratory);
<bullet> Weather parameters and water conditions;
<bullet> The number of marine mammals observed, by species,
relative to the pile location and if pile driving or removal was
occurring at time of sighting;
<bullet> Distance and bearings of each marine mammal observed to
the pile being driven or removed;
<bullet> Description of marine mammal behavior patterns, including
direction of travel;
<bullet> Age and sex class, if possible, of all marine mammals
observed; and,
<bullet> Detailed information about implementation of any
mitigation triggered (such as shutdowns and delays), a description of
specific actions that ensued, and resulting behavior of the animal if
any.
Reporting
PG&E 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 (beginning and end) of all marine mammal
monitoring;
<bullet> Construction activities occurring during each daily
observation period including: (a) the number and types of piles driven
and the method; and (b) total duration of driving time for each pile
(vibratory driving) and number of strikes for each pile (impact
driving);
[[Page 5876]]
<bullet> PSO locations during marine mammal monitoring;
<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;
<bullet> For each observation of a marine mammal the following must
be recorded: (a) Name of PSO who sighted the animal(s) and PSO location
and activity at time of sighting; (b) time of sighting; (c)
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; (d)
distance and location of each observed marine mammal relative to pile
being driven or removed for each sighting; (e) estimated number of
animals (min/max/best estimate); (f) estimated number of animals by
cohort (adults, juveniles, neonates, group composition, etc.); (g)
animal's closest point of approach and estimated time spent within the
harassment zone; (h) 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);
<bullet> Number of marine mammals detected within the harassment
zones, by species; and,
<bullet> Detailed information about implementation of any
mitigation (e.g. shutdowns and delays), a description of specific
actions that ensued, and resulting changes in behavior of the
animal(s), if any.
Reporting Injured or Dead Marine Mammals
In the event that personnel involved in the construction activities
discover an injured or dead marine mammal, PG&E will report the
incident to the Office of Protected Resources (OPR)
(<a href="/cdn-cgi/l/email-protection#4010126e0914106e0d2f2e29342f32292e271225302f323433002e2f21216e272f36"><span class="__cf_email__" data-cfemail="4212106c0b16126c0f2d2c2b362d302b2c251027322d303631022c2d23236c252d34">[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, PG&E 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. PG&E will not resume their activities until notified by
NMFS. The report will include the following:
<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 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 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
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
disturbances. The potential for harassment is minimized through
construction methods and the implementation of planned mitigation
strategies (see Mitigation section).
Behavioral responses of marine mammals to pile driving at the
project site, if any, are expected to be mild and temporary. Marine
mammals within the Level B harassment zone may not show any visual cues
they are disturbed by activities or could become alert, avoid the area,
leave the area, or display other mild responses that are not observable
such as changes in vocalization patterns. Given the short duration of
noise-generating activities per day and that pile driving and removal
will occur over approximately 50 days during a span of 5 months, any
harassment will be temporary. There are no other areas or times of
known biological importance for any of the affected species.
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 incidental take authorization are
listed as threatened or endangered under the ESA. Only one stock, the
Eastern North Pacific Stock of the northern fur seal, is listed as
depleted under the MMPA. However, we do not expect the authorizations
in this action to affect the stock. No injury or mortality is
authorized, take by Level B harassment is limited (five takes over the
duration of the project), and the action should have no effect on the
reproduction of this species. In addition, the five authorized takes
for the northern fur seal include both the depleted Eastern
[[Page 5877]]
North Pacific Stock and the California stock, which is not depleted.
The relatively low marine mammal occurrences in the area, 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.
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.
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;
<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
or marine mammal habitat; and,
<bullet> The presumed efficacy of the mitigation measures in
reducing the effects of the specified activity.
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 stocks (See table 7). These are all
likely conservative estimates because they assume 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 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 will 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) and
alternatives 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 NAO 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 this IHA qualifies to be categorically excluded from
further NEPA review.
Authorization
NMFS has issued an IHA to PG&E for the potential harassment of
small numbers of seven marine mammal species incidental to the sediment
remediation project in San Francisco Bay, that includes the previously
explained mitigation, monitoring, and reporting requirements.
Dated: January 25, 2024.
Catherine G. Marzin,
Acting Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2024-01790 Filed 1-29-24; 8:45 am]
BILLING CODE 3510-22-P
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