Notice2022-08888
Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Chevron Point Orient Wharf Removal
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
April 27, 2022
Issuing agencies
Commerce DepartmentNational Oceanic and Atmospheric Administration
Abstract
NMFS has received a request from Chevron Products Company (Chevron) for authorization to take marine mammals incidental to 2 years activity of vibratory pile removal associated with the Point Orient Wharf Removal in San Francisco Bay, California (CA). Pursuant to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposal to issue two consecutive one-year incidental harassment authorizations (IHA) to incidentally take marine mammals during the specified activities. NMFS is also requesting comments on a possible one-time, one-year renewal that could be issued under certain circumstances and if all requirements are met, as described in Request for Public Comments at the end of this notice. NMFS will consider public comments prior to making any final decision on the issuance of the requested MMPA authorizations and agency responses will be summarized in the final notice of our decision.
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<title>Federal Register, Volume 87 Issue 81 (Wednesday, April 27, 2022)</title>
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[Federal Register Volume 87, Number 81 (Wednesday, April 27, 2022)]
[Notices]
[Pages 24950-24970]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-08888]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
[RTID 0648-XB948]
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to Chevron Point Orient Wharf Removal
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorizations; request
for comments on proposed authorizations and possible renewal.
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SUMMARY: NMFS has received a request from Chevron Products Company
(Chevron) for authorization to take marine mammals incidental to 2
years activity of vibratory pile removal associated with the Point
Orient Wharf Removal in San Francisco Bay, California (CA). Pursuant to
the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on
its proposal to issue two consecutive one-year incidental harassment
authorizations (IHA) to incidentally take marine mammals during the
specified activities. NMFS is also requesting comments on a possible
one-time, one-year renewal that could be issued under certain
circumstances and if all requirements are met, as described in Request
for Public Comments at the end of this notice. NMFS will consider
public comments prior to making any final
[[Page 24951]]
decision on the issuance of the requested MMPA authorizations and
agency responses will be summarized in the final notice of our
decision.
DATES: Comments and information must be received no later than May 27,
2022.
ADDRESSES: Comments should be addressed to Jolie Harrison, Chief,
Permits and Conservation Division, Office of Protected Resources,
National Marine Fisheries Service. Written comments should be submitted
via email to <a href="/cdn-cgi/l/email-protection#733a27235d07120a1f1c01331d1c12125d141c05"><span class="__cf_email__" data-cfemail="3a736e6a144e5b435655487a54555b5b145d554c">[email protected]</span></a>.
Instructions: NMFS is not responsible for comments sent by any
other method, to any other address or individual, or received after the
end of the comment period. Comments, including all attachments, must
not exceed a 25-megabyte file size. All comments received are a part of
the public record and will generally be posted online at
<a href="http://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a> without change. All personal identifying
information (e.g., name, address) voluntarily submitted by the
commenter may be publicly accessible. Do not submit confidential
business information or otherwise sensitive or protected information.
FOR FURTHER INFORMATION CONTACT: Jessica Taylor, Office of Protected
Resources, NMFS, (301) 427-8401. Electronic copies of the application
and supporting documents, as well as a list of the references cited in
this document, may be obtained online at: <a href="https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</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 incidental harassment authorization 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.
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
preliminarily determined that the issuance of the proposed IHAs qualify
to be categorically excluded from further NEPA review. We will review
all comments submitted in response to this notice prior to concluding
our NEPA process or making a final decision on the IHA requests.
Summary of Request
On January 11, 2022, NMFS received a request from Chevron for 2
consecutive IHAs to take marine mammals incidental to vibratory pile
removal during the Point Orient Wharf Removal in San Francisco Bay, CA
over a two-year period. The application was deemed adequate and
complete on April 4, 2022. Chevron's request is for take of seven
species of marine mammals by Level B harassment only. Neither Chevron
nor NMFS expects serious injury or mortality to result from this
activity and, therefore, an IHA is appropriate.
NMFS previously issued IHAs to Chevron for pile driving and removal
work (82 FR 27240, June 14, 2017; 83 FR 27548, June 13, 2018; 84 FR
28474, June 19, 2019; 85 FR 37064, June 19, 2020; 86 FR 28582, May 27,
2021). 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 Description of
Marine Mammals in Areas of the Specified Activity section.
Description of Proposed Activity
Overview
Chevron proposes to remove the decommissioned Point Orient Wharf
(the Wharf) located in northeastern San Francisco Bay (the Bay), CA.
The Point Orient Wharf covers an area of approximately 8,094 m (2
acres) and extends approximately 396 m (1,300 ft) into San Francisco
Bay. Over the course of 2 years spanning June 1-November 30, 2022 and
June 1-November 30, 2023, Chevron will remove the Wharf in its entirety
and restore eelgrass to the surrounding subtidal habitat. Piles will be
extracted using a variety of methods, including vibratory pile removal.
Vibratory pile removal is a non-impulsive continuous noise source that
may result in the incidental take of marine mammals by Level B
harassment in the form of behavioral harassment.
Chevron has requested an IHA concurrently for each of the 2 project
years. Given the similarities in activities between project years, NMFS
is issuing this single Federal Register notice to solicit public
comments on the issuance of the two similar, but separate, IHAs.
Dates and Duration
Chevron anticipates that removal of the Wharf will occur over 2
years. The in-water work window is anticipated to last from June 1 to
November 30 in 2022 (Year 1) and June 1 to November 30 in 2023 (Year
2), although vibratory extraction is expected to occur only in 12 weeks
of each annual work period. NMFS expects that a seasonal work window of
June through November each year will best protect sensitive life stages
of listed fish species in the area. Construction will consist of
approximately 100 in-water work days only during daylight hours. Year 1
IHA would be valid from June 1, 2022-May 31, 2023, and Year 2 IHA would
span June 1, 2023-May 31, 2024.
Specific Geographic Region
The Point Orient Wharf is located in the central Bay on the western
side of Point San Pablo, approximately 2.9 km
[[Page 24952]]
(1.8 miles) north of the eastern terminus of the Richmond San-Rafael
Bridge (RSRB) in Contra Costa County (Figure 1). The Brothers Islands
and Lighthouse are approximately 800 meters (2,600 feet) to the north
of the Wharf. The Point Orient Wharf is located near a shipping
channel, and regular boat traffic in the vicinity accounts for the
majority of ambient underwater noise in the area.
The Point Orient Wharf consists of two portions: a narrower portion
of the Wharf that runs perpendicular to the shoreline, known as the
Causeway and which will be removed in Year 1, and a wider portion that
runs parallel to the shoreline, known as the Main Wharf and which will
be removed in Year 2. While the Wharf was in use, a dredged channel and
berthing area with a depth of approximately 10 m (33 feet) below mean
lower low water (MLLW) was maintained on the western side of the Main
Wharf. However, since the Wharf was decommissioned, the channel and
berthing area have filled in with sediment. A deep scour pocket of
approximately 15.2 m (50 feet) below MLLW is maintained by tidal action
west of the Main Wharf and 10 m (33 feet) below MLLW southeast of the
Main Wharf. Bathymetry along the Causeway ranges from the upper
intertidal at the eastern end of the Causeway to a depth of
approximately 4.9 m (16 feet) below MLLW at its western end.
BILLING CODE 3510-22-P
[GRAPHIC] [TIFF OMITTED] TN27AP22.003
BILLING CODE 3510-22-C
Detailed Description of Specific Activity
Chevron intends to remove the Wharf in its entirety, and restore
eelgrass to the subtidal habitat in areas under the Causeway portion of
the Wharf that are currently affected by the shading imposed by the
structure. This project will utilize direct pull or vibratory removal
methods to extract approximately 910 timber piles and 90 steel piles
from the Bay. During Year 1, Chevron plans to remove the Causeway
portion of the Wharf and repair an area of unstable shoreline
embankment just north of the Causeway. The shoreline embankment
stabilization, involving only upland work, will not result in the take
of marine mammals and will not be considered further. Removal of the
Causeway will involve the extraction of 534 12'' treated timber piles
(133 of which are concrete encased) through direct pull or vibratory
removal methods. Only one pile will be removed at a time. The condition
of the piles would dictate the methods that would be implemented. If
the piles have sufficient structural integrity, the pile would be
wrapped with chain or cable attached to a crane and pulled directly
upward, pulling the pile from the sediment. Vibratory extraction would
likely be the primary method of removal and involve the use of a
vibratory pile driving hammer to loosen the pile with vibration. The
vibration causes liquefaction of the surrounding sediment, allowing the
pile to be pulled straight up and out. If a pile is unable to be
removed entirely or breaks when pulled, the pile may be cut 0.6 m (2
feet) under the mudline using a hydraulic chainsaw or underwater torch
cutting system, however, vibratory extraction would be the most
impactful removal method. Additional materials removed from the
Causeway would include 488 m (1,600 feet) of process piping, steel
pipes, wooden decking, pipe supports, light poles, and pile caps.
Removal of these additional materials from the above-water portion of
the pier would
[[Page 24953]]
not result in takes of marine mammals and as such, this will not be
considered further. All materials removed would be loaded onto barges
for transport to a permitted disposal or recycling facility.
During Year 2, the Main Wharf portion would be removed and eelgrass
would be planted after its removal. Removal of the Main Wharf would
include the removal of 376 12'' timber piles (156 of which are concrete
encased), 34 36'' steel piles, 40 30'' piles, and 16 24'' piles by
similar methods as in Year 1. Only one pile would be removed at a time,
and only one type of pile would be removed per day. Additional
materials removed from the Main Wharf would include steel pipe bridges,
steel fendering, and wooden decking. Removing these additional
materials would not result in takes of marine mammals and will not be
considered further. As in Year 1, all materials removed would be loaded
onto barges for transport to a permitted disposal or recycling
facility. After the Main Wharf is removed, eelgrass will be planted in
suitable areas to restore habitat quality to the Bay. Planting eelgrass
will not result in the take of marine mammals and will not be
considered further. Table 1 below provides additional detail on
duration of construction activities:
Table 1--Summary of Pile Removal Activities by Year
----------------------------------------------------------------------------------------------------------------
Approximate
duration of Approximate
Pile type Diameter Number of vibration per number of Total number
(inches) piles pile piles removed of work days
(minutes) per day
----------------------------------------------------------------------------------------------------------------
Year 1 Vibratory Extraction
----------------------------------------------------------------------------------------------------------------
Timber........................ 12.............. 401 6 18 * 35
Timber concrete encased....... 18 (12-inch 133 9 11
timber core).
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Year 2 Vibratory Extraction
----------------------------------------------------------------------------------------------------------------
Timber........................ 12.............. 220 6 18 * 27
Timber concrete encased....... 18 (12-inch 156 9 11
timber core).
Steel......................... 36.............. 34 45 2 18
Steel......................... 30.............. 40 32 3 10
Steel......................... 24.............. 16 26 4 6
----------------------------------------------------------------------------------------------------------------
* Removal of bare timber pile and concrete encased piles will be co-mingled during these work days.
Proposed mitigation, monitoring, and reporting measures are
described in detail later in this document (please see Proposed
Mitigation and Proposed Monitoring and Reporting).
Description of Marine Mammals in the Area of Specified Activities
Sections 3 and 4 of the application summarize available information
regarding status and trends, distribution and habitat preferences, and
behavior and life history, of the potentially affected species.
Additional information regarding population trends and threats may be
found in NMFS's Stock Assessment Reports (SARs; <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments">https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments</a>) and more general information about these species
(e.g., physical and behavioral descriptions) may be found on NMFS's
website (<a href="https://www.fisheries.noaa.gov/find-species">https://www.fisheries.noaa.gov/find-species</a>).
Table 2 lists all species or stocks for which take is expected and
proposed to be authorized for both proposed IHAs, 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. For taxonomy, we follow
Committee on Taxonomy (2021). PBR is defined by the MMPA as the maximum
number of animals, not including natural mortalities, that may be
removed from a marine mammal stock while allowing that stock to reach
or maintain its optimum sustainable population (as described in NMFS's
SARs). While no mortality is anticipated or authorized here, PBR and
annual serious injury and mortality from anthropogenic sources are
included here as gross indicators of the status of the species and
other threats.
Marine mammal abundance estimates presented in this document
represent the total number of individuals that make up a given stock or
the total number estimated within a particular study or survey area.
NMFS's stock abundance estimates for most species represent the total
estimate of individuals within the geographic area, if known, that
comprises that stock. For some species, this geographic area may extend
beyond U.S. waters. All managed stocks in this region are assessed in
NMFS's U.S. Pacific Marine Mammal SARs (e.g., Carretta et al., 2021).
All values presented in Table 2 are the most recent available at the
time of publication and are available in the 2020 SARs (Carretta et
al., 2021) and draft 2021 SARs (available online at: <a href="https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports">https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports</a>).
Table 2--Marine Mammals Likely To Occur in the Project Area
--------------------------------------------------------------------------------------------------------------------------------------------------------
ESA/ MMPA status; Stock abundance (CV,
Common name Scientific name Stock strategic (Y/N) Nmin, most recent PBR Annual M/
\1\ abundance survey) \2\ SI \3\
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
[[Page 24954]]
Gray whale...................... Eschrichtius robustus.. Eastern N Pacific...... -, -, N 29960 (0.05, 25,849, 801 131
2016).
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
Bottlenose Dolphin.............. Tursiops truncatus..... California Coastal..... -, -, N 453 (0.06, 346, 2011). 2.7 >=2.0
Family Phocoenidae (porpoises):
Harbor Porpoise................. Phocoena phocoena...... San Francisco-Russian -, -, N 7,777 (0.62, 4,811, 73 >=0.4
River. 2017).
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Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and
sea lions):
California Sea Lion............. Zalophus californianus. U.S.................... -, -, N 257,606 (N/A, 233,515, 14,011 >320
2014).
Family Phocidae (earless seals):
Harbor Seal..................... Phoca vitulina......... California............. -, -, N 30,968 (N/A, 27,348, 1,641 43
2012).
Northern Elephant Seal.......... Mirounga angustirostris California Breeding.... -, -, N 187,386 (N/A, 85,369, 5,122 5.3
2013).
Northern Fur Seal............... Callorhinus ursinus.... California............. -, D, N 14,050 (N/A, 7,524, 451 1.8
2013).
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\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: <a href="http://www.nmfs.noaa.gov/pr/sars/">www.nmfs.noaa.gov/pr/sars/</a>. CV is coefficient of variation; Nmin is the minimum estimate of
stock abundance. In some cases, CV is not applicable [explain if this is the case].
\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 (mortality/serious injury) 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.
As indicated above, all 7 species (with 7 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 proposed survey areas are included in Table 4-
1 of the IHA application. While Steller sea lions (Eumetopias jubatus)
and humpback whales (Megaptera noveangliae) have been documented in the
area, their occurrence in the Bay is sufficiently rare that take is not
expected to occur, and they are not discussed further beyond the
explanation provided here.
Steller sea lions have been reported at A[ntilde]o Nuevo Island
between Santa Cruz and Half Moon Bay as well as at the Farallon Islands
about 48 kilometers (30 miles) off the coast of San Francisco (Fuller
2012). However, very few studies have detected Steller sea lions in San
Francisco Bay. The San Francisco Bay Subtidal Habitat Goals Report
contains one reference to Steller sea lions in the Bay (Cohen 2010),
however, this species is considered a rare visitor and not expected to
occur in the project area during construction activities.
Humpback whales are also rare visitors to the project area as they
are more commonly observed in offshore waters or just inside the Bay
entrance. Limited sightings of humpback whales have occurred inside the
Bay. In 1985, one humpback whale traveled into the Bay and up the
Sacramento River; the same whale re-entered the Bay in the fall of 1990
and stranded (Fimrite 2005). In May 2007, a humpback whale mother and
calf spent slightly more than 2 weeks in the Bay and Sacramento River
before returning to coastal waters (CBS News 2007). Due to the limited
sightings of humpback whales in the Bay, this species is not expected
to occur in the project area during construction activities.
Gray Whale
Gray whales are large baleen whales, easily recognized by their
mottled gray color and lack of a dorsal fin. They are one of the most
frequently seen whales along the California coast. Gray whales feed in
the northern waters, primarily off the Bering, Chukchi, and western
Beaufort seas during the summer, although a small number of whales,
known as the Pacific Coast Feeding Group (PCFG), is known to feed along
the Pacific coast between Kodiak Island, AK and northern California
(Carretta et al., 2021). Most whales begin their southward migration
from the feeding grounds in November and December, traveling south
along the eastern Pacific coast to their winter breeding and calving
areas in lagoons along the coast of Baja California, Mexico. The
southward migration occurs from December through February, peaking in
January (NOAA NCCOS 2007). The northward migration to the feeding
occurs from February through May, peaking in March (NOAA NCCOS 2007).
Gray whales also feed in nearshore waters just outside of San Francisco
Bay, and a few individuals will enter San Francisco Bay during the
northward migration. Since 2019, it has become more common for gray
whales on their northward migration to enter San Francisco Bay during
the months of February and March to feed (Bartlett 2022).
Monitors from the RSRB recorded 12 living and 2 dead gray whales in
either the Central or North Bay. All but 2 sightings occurred during
the months of April and May: One whale was sighted in June and one in
October (Winning 2008). In March 2022, a mom and calf were sighted
between Alcatraz and Angel Island (Bartlett 2022). During the spring of
2019, 12 dead gray whales washed up on the shoreline of the Bay and on
Ocean Beach on the west side of San Francisco. Since 2018, the number
of gray whale strandings per year in the Bay area have varied between 5
whales in 2018 and 2020, and 15 whales in 2021 (Bartlett 2022). Ship
strikes, malnutrition, and entanglement were the cause of death for
strandings (Bartlett 2022; TMMC 2019). The Oceanic Society found that
all age classes of gray whales may enter the Bay, either as singles or
in groups of up to five individuals (Winning 2008). It is likely that
gray whales would typically
[[Page 24955]]
enter the Bay from February to May; however, it is also possible that a
gray whale may enter the project area during pile extraction.
Eastern North Pacific gray whales experienced an unusual mortality
event (UME) beginning in 2019 when large numbers of whales began
stranding from Mexico to Alaska. Necropsy results indicated that many
whales showed signs of nutritional stress (NOAA 2020). This UME is
ongoing and similar to that of 1999 and 2000 when large numbers of gray
whales stranded along the eastern Pacific coast (Moore et al., 2001;
Gulland et al., 2005). Oceanographic factors limiting food availability
for whales was identified as a likely cause of the prior UME and may
also be influencing the current UME (LeBouef et al., 2000; Moore et
al., 2001; Minobe 2002; Gulland et al., 2005).
Bottlenose Dolphin
The common bottlenose dolphin is found in all oceans across the
globe, and is one of the most commonly observed marine mammal species
in coastal waters and estuaries. Two genetically distinct stocks occur
off the coast of California, the California coastal stock and the
California/Oregon/Washington offshore stock. The range of the
California coastal stock has expanded northward along the coast since
the 1982-1983 El Ni[ntilde]o event (Hansen and Defran, 1990; Wells et
al., 1990). This stock now occurs as far north as the San Francisco Bay
region. Individuals show very little site fidelity to any portion of
the California coast (Szczepaniak et al., 2013; Weller et al., 2016),
although, as of 2019, the Golden Gate Cetacean Research Dolphin Project
had identified 91 individual dolphins in the Bay (APER 2019). Since
2008, coastal bottlenose dolphins have been observed regularly in San
Francisco Bay with many observations occurring in the proximity of the
Golden Gate near the mouth of the Bay (Bay Nature Institute 2014). A
limited number of individuals may approach the project area during in-
water construction.
Harbor Porpoise
Harbor porpoises are typically found in cool temperate to sub-polar
waters less than 62.6 degrees Fahrenheit (17 degrees Celsius) (Read
1999) where prey aggregations are concentrated (Watts and Gaskin,
1985). In the eastern Pacific, harbor porpoises occur in coastal and
inland waters from Point Conception, California to Alaska (Gaskin
1984). Four genetically distinct stocks have been identified along the
coast of California (Carretta et al., 2021). The non-migratory San
Francisco-Russian River stock ranges from Pescadero to Point Arena,
California, utilizes relatively shallow nearshore waters (<100 meters),
and feeds on small schooling fishes such as northern anchovy and
Pacific herring which enter San Francisco Bay (Caretta et al., 2021;
Stern et al., 2017). Harbor porpoises tend to occur in small groups and
are considered to be relatively shy animals. Previous estimates for
harbor porpoises were based upon aerial surveys conducted between
coastal waters and the 50 fm-isobath (Forney 1999), however, surveys
have been expanded further offshore and to include shipboard platforms.
Before 2008, harbor porpoises were observed primarily outside of
San Francisco Bay although the Bay has historically been considered
habitat for harbor porpoises (Broughton 1999). Recently, there have
been increasingly common observations of harbor porpoises within the
Bay (Duffy 2015; Stern et al., 2017). From 2011-2014, a visual count
conducted by the Golden Gate Cetacean Research (GGCR) program
identified 2,698 porpoise groups from the Golden Gate Bridge (Stern et
al., 2017). Harbor porpoise movements into the Bay are linked to tidal
cycle with the greatest numbers of porpoises being sighted during high
tide to ebb tide periods. Movements into the Bay are likely influenced
by prey availability (Duffy 2015; Stern et al., 2017). Although harbor
porpoise sightings are generally concentrated in the vicinity of the
Golden Gate Bridge and Angel Island, southwest of the project site
(Keener 2011), this species is more frequently venturing into the Bay
east of Angel Island and may approach the project area during pile
removal activities.
California Sea Lion
California sea lions breed mainly on offshore islands, ranging from
Southern California's Channel Islands to Mexico during the spring
(Heath and Perrin, 2008), although a few pups have been born on
A[ntilde]o Nuevo and the Farallon Islands (TMMC 2020). During the non-
breeding season, adult and sub-adult males as well as juveniles migrate
northward along the coast, to central and northern California, Oregon,
Washington, and Vancouver Island (Jefferson et al., 1993). They return
south the following spring (Lowry and Forney, 2005; Heath and Perrin,
2008) while females tend to remain closer to rookeries (Antonelis et
al., 1990; Melin et al., 2008). Based upon statistical analysis of
annual pup count, annual survivorship, and human-induced impacts, the
California stock appears to have experienced an annual increase from
1975-2014 (Laake et al., 2018).
Although California sea lions forage and conduct many activities
within the water, they also use haul outs. In San Francisco Bay, sea
lions haul out primarily on floating docks at Pier 39 at the
Fisherman's Wharf area of the San Francisco Marina, approximately 12.5
kilometers (7.8 miles) southwest of the project area. In addition to
the Pier 39 haul out, California sea lions haul out on buoys, wharfs,
and similar structures throughout the Bay. Occurrence of sea lions in
typically lowest in June during the breeding season and higher during
El Ni[ntilde]o seasons. During monitoring for the RSRB project,
observers sighted at least 90 sea lions in the northern Bay and at
least 57 in the central Bay, although no pupping activity was observed
(Caltrans 2012).
California sea lions are mainly seen swimming off the San Francisco
and Marin shorelines within the Bay, but may occasionally enter the
project area to forage. They feed seasonally on schooling fish and
cephalopods, including salmon, herring, sardines, anchovy, mackerel,
whiting, rockfish, and squid (Lowry et al., 1990, 1991; Lowry and
Carretta, 1999; Weise 2000; Carretta et al., 2021). Seasonal and annual
dietary shifts vary with environmental fluctuations that affect prey
populations. In central California sea lion populations, short term
seasonal variations in diet are related to prey movement and life
history patterns while long-term annual changes correlate to large-
scale ocean climate shifts and foraging competition with commercial
fisheries (Weise and Harvey 2008; McClatchie et al., 2016). Climate
change, specifically increasing sea surface temperatures in the
California current, negatively impact prey species availability and
reduce California sea lion survival rates (DeLong et al., 2017; Laake
et al., 2018). Other conservation concerns for California sea lions
include vessel strikes, non-commercial fishery human caused mortality,
hookworms, and competition for forage with commercial fisheries
(Carretta et al., 2018; Carretta et al., 2021).
California sea lions experienced a UME, not correlated to an El
Ni[ntilde]o event, from 2013-2017 (Carretta et al., 2021). Pup and
juvenile age classes experienced high mortality during this time,
likely attributed to sea lion prey availability, specifically sardines.
California sea lions are also susceptible to the algal neurotoxin,
domoic acid (Brodie et al., 2006; Carretta et al., 2021). This
neurotoxin is expected to cause future mortalities among California sea
lions due to the
[[Page 24956]]
prevalence of harmful algal blooms within their habitat.
In San Francisco Bay, California sea lions have been observed
foraging near Pier 39, in the shipping channel south of Yerba Buena
Island, and along the west side of the Chevron Long Wharf (AECOM 2019).
The relatively deep shipping channel west and north of the Point Orient
Wharf would also provide foraging area for sea lions. During monitoring
at the Chevron Long Wharf Maintenance and Efficiency Project (CLWMEP),
Protected Species Observers (PSOs) documented a sea lion foraging on a
small shark in 2019 and 8 sea lions in the project area in 2020 (AECOM
2019; 2020). As sea lions may forage widely throughout San Francisco
Bay, there is the potential that this species may enter the project
area during construction activities.
Harbor Seal
Pacific harbor seals are distributed from Baja California north to
the Aleutian Islands of Alaska. Seals primarily haul out on remote
mainland and island beaches, reefs, and estuary areas. At haul outs,
they will congregate to rest, socialize, breed, and molt. Haul outs are
relatively consistent from year to year (Kopec and Harvey, 1995), and
females have been documented to return to their own natal haul out when
breeding (Green et al., 2006).
The Pacific harbor seal population experienced an increase from
1981-2004, followed by a steady decrease from between 2005-2010. The
maximum statewide count showed that the California stock sharply
declined in 2009 and 2012 (Duncan 2019). The California Department of
Transportation (Caltrans) conducted extensive marine mammal surveys in
San Francisco Bay before and during seismic retrofit on the RSRB from
1998-2002. Caltrans determined that a minimum of 500 harbor seals occur
within San Francisco Bay (Green et al., 2002), an estimate that agrees
with more recent seal counts (Lowry et al., 2008; Codde et al., 2020).
The California harbor seal stock may be stabilizing at or near carrying
capacity, although conservation concerns such as vessel strikes,
disturbance, fishing gear entanglement, and habitat loss are still a
concern in the San Francisco Bay area (Duncan 2019). The nearest major
haul out site to the project area is Castro Rocks, located
approximately 2,600 meters (1.6 miles) south of the southernmost point
on the Wharf. Use of Castro Rocks as a haul out site has been
increasing over the years (Codde et al., 2020). Smaller numbers of
harbor seals have also been reported to haul out on the western Brother
Island, approximately 800 meters (2,600 ft) to the north of the Wharf.
The number of harbor seals in San Francisco Bay increases during
the winter foraging period as compared to the spring breeding season.
In the Bay, harbor seals are known to forage on a variety of fish,
crustaceans, and cephalopods in found in shallow intertidal waters.
Based upon fecal samples obtained from haul out sites in the Bay, major
prey items include the yellowfin goby, northern anchovy, Pacific
herring, staghorn sculpin, plainfin midshipman, and white croaker
(Harvey and Torok, 1994). Seals haul out on Castro Rocks year-round
during medium to low tides, and usage of this haul out site is highest
during the summer molting period of June-July. Based upon visual
monitoring conducted by PSOs during the CLWMEP in 2019 (AECOM 2020),
the number of hauled out seals on Castro Rocks may vary greatly, from 0
to 50 seals, depending upon the tide. Due to the proximity of the Wharf
to the Castro Rocks haul out site, it is likely that harbor seals will
be in the project area during construction activities.
Northern Elephant Seal
Northern elephant seals commonly pup, breed, rest, and molt on
California coastal mainland and island sites. In the vicinity of San
Francisco Bay, seals breed, molt, and haul out at A[ntilde]o Nuevo
Island, the Farallon Islands, and Point Reyes Seashore (Lowry et al.,
2014). The birthing and breeding season occurs from December through
March. Pups remain onshore or in adjacent shallow waters through May,
when they may make brief stops in San Francisco Bay (Caltrans 2015).
Pups of the year may also make brief stops in the Bay when they return
in late summer and fall to haul out at rookery sites. Adults typically
reside in offshore pelagic waters when not breeding or molting,
however, a healthy juvenile male was observed basking at Aquatic Park
in San Francisco in the spring of 2019 (Hern[aacute]ndez 2020).
Caltrans (2015) estimates that approximately 100 juvenile northern
elephant seals of the California breeding stock strand in San Francisco
Bay each year. Although rare visitors to the Bay, it is possible that a
few individuals may be present during construction activities.
Northern Fur Seal
Northern fur seals range from southern California north to the
Bering Sea, and west to the Okhotsk Sea and Honshu Island, Japan in the
west (Carretta et al., 2021). The majority of the population breeds on
the Pribilof Islands in the southern Bering Sea, although a small
percentage of the population breed at San Miguel Island and the
Farallon Islands off the coast of California. Northern fur seals show
high site fidelity to breeding and rookery locations, and may swim long
distances for prey. Their diet is composed of small schooling fish such
as walleye Pollock, herring, hake, anchovy, and squid. Diet and
population trends vary with environmental conditions, such as El
Ni[ntilde]o (Carretta et al., 2021). The California stock of northern
fur seals is known to forage in waters outside of San Francisco Bay.
Juvenile northern fur seals occasionally strand in San Francisco Bay,
especially during El Ni[ntilde]o events (TMMC 2016). The Marine Mammal
Center (TMMC) responds to approximately five northern fur seal
strandings per year in San Francisco Bay (TMMC 2016). Although rarely
observed in San Francisco Bay, it is possible individuals may be
present during construction activities.
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. Current data indicate that 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) recommended that marine mammals be divided
into functional hearing groups based on directly measured or estimated
hearing ranges on the basis of available behavioral response data,
audiograms derived using auditory evoked potential techniques,
anatomical modeling, and other data. 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 3.
[[Page 24957]]
Table 3--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.
Seven marine mammal species (three cetacean and four pinniped (one
otariid and three phocid) species) have the reasonable potential to co-
occur with the proposed survey activities. Please refer to Table 2. Of
the cetacean species that may be present, one is classified as low-
frequency cetaceans (i.e., all mysticete species), one is classified as
mid-frequency cetaceans (i.e., all delphinid and ziphiid species and
the sperm whale), and one is classified as high-frequency cetaceans
(i.e., harbor porpoise and Kogia spp.).
Potential Effects of Specified Activities on Marine Mammals and Their
Habitat
This section includes a summary and discussion of the ways that
components of the specified activity may impact marine mammals and
their habitat. The Estimated Take section later in this document
includes a quantitative analysis of the number of individuals that are
expected to be taken by this activity. The Negligible Impact Analysis
and Determination section considers the content of this section, the
Estimated Take section, and the Proposed Mitigation section, to draw
conclusions regarding the likely impacts of these activities on the
reproductive success or survivorship of individuals and how those
impacts on individuals are likely to impact marine mammal species or
stocks.
The marine soundscape is comprised of both ambient and
anthropogenic sounds. Ambient sound is defined as the all-encompassing
sound in a given place and is usually a composite of sound from many
sources both near and far. The sound level of an area is defined by the
total acoustical energy being generated by known and unknown sources.
These sources may include physical (e.g., waves, wind, precipitation,
earthquakes, ice, atmospheric sound), biological (e.g., sounds produced
by marine mammals, fish, and invertebrates), and anthropogenic sound
(e.g., vessels, dredging, aircraft, construction).
The sum of the various natural and anthropogenic sound sources at
any given location and time--which comprise ``ambient'' or
``background'' sound--depends not only on the source levels (determined
by current weather conditions and levels of biological and shipping
activity) but also on the ability of sound to propagate through the
marine environment. In turn, sound propagation is dependent upon the
spatially and temporally varying properties of the water column and sea
floor. As a result of the dependence upon a large number of varying
factors, ambient sound levels can be expected to vary widely over both
coarse and fine spatial and temporal scales. Sound levels at a given
frequency and location can vary by 10-20 dB per day (Richardson et al.,
1995). The result is that, depending upon the source type and its
intensity, sound from the specified activity may be a negligible
addition to the local environment or could form a distinctive signal
that could affect marine mammals.
In-water construction activities associated with the project would
include vibratory pile removal, a type of non-impulsive sound. Non-
impulsive sounds (e.g., aircraft, machinery operations such as drilling
or dredging, vibratory pile driving/removal, and active sonar systems)
can be broadband, narrowband, or tonal, brief or prolonged (continuous
or intermittent), and typically do not have the high peak sound
pressure with rapid rise/decay time that impulsive sounds do (ANSI
1995; NIOSH 1998; NMFS 2018). Impulsive sounds (e.g., explosions,
gunshots, sonic booms, impact pile driving) are typically transient,
brief (less than 1 second), broadband, and consist of high peak sound
pressure with rapid rise time and rapid decay (ANSI 1986; NIOSH 1998;
ANSI 2005; NMFS 2018). The distinction between impulsive and non-
impulsive sounds is important because they have differing potential to
cause physical effects, particularly with regard to hearing (e.g., Ward
1997 in Southall et al., 2007).
Impact hammers operate by repeatedly dropping a heavy piston onto a
pile to drive the pile into the substrate. Sound generated by impact
hammers is characterized by rapid rise times and high peak levels, a
potentially injurious combination (Hastings and Popper, 2005).
Vibratory hammers install or remove piles by vibrating them, allowing
the weight of the hammer to push the pile into the sediment during
installation. The vibrations produced also cause liquefaction of the
substrate surrounding the pile, enabling the pile to be extracted or
driven into the ground more easily. Vibratory hammers produce
significantly less sound than impact hammers. Peak sound pressure
levels (SPLs) may be 180 dB or greater, but are generally 10 to 20 dB
lower than SPLs generated during pile driving of the same size pile
(Oestman et al., 2009). Rise time is slower, reducing the probability
and severity of injury, and sound energy is distributed over a greater
amount of time (Nedwell and Edwards, 2002; Carlson et al., 2005). The
likely or possible impacts of Chevron's proposed activity on marine
mammals could involve both non-acoustic and acoustic stressors.
Potential non-acoustic stressors could result from the physical
presence of equipment and personnel; however, any impacts to marine
mammals are expected to be acoustic in nature. Acoustic stressors
involve effects of vibratory pile removal.
[[Page 24958]]
Acoustic Impacts
In general, animals exposed to natural or anthropogenic sound may
experience physical and psychological effects, ranging in magnitude
from none to severe (Southall et al., 2007). Exposure to pile removal
noise has the potential to result in auditory threshold shift and
behavioral reactions (e.g., avoidance, temporary cessation of foraging
and vocalizing, changes in dive behavior). Exposure to anthropogenic
noise can also lead to non-observable physiological responses, such as
an increase in stress hormones. Additional noise in a marine mammal's
habitat can mask acoustic cues used by marine mammals to carry out
daily functions such as communication and predator and prey detection.
The effects of pile removal noise on marine mammals are dependent upon
several factors, including but not limited to the species, age, and sex
class (e.g., adult male vs. mom with calf), duration of exposure, the
distance between the pile and the animal, received levels, behavior at
time of exposure, and previous history with exposure (Wartzok et al.,
2004; Southall et al., 2007). Here we discuss the physical auditory
effects (threshold shifts) followed by behavioral effects and potential
impacts on habitat.
NMFS defines a noise-induced threshold (TS) as a change, usually an
increase, in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a previously established
reference level (NMFS 2018). The amount of threshold shift is
customarily expressed in decibels (dB). A TS can be permanent or
temporary. As described in NMFS (2018), there are numerous factors to
consider when examining the consequence of TS including, but not
limited to, the signal temporal pattern (e.g., impulsive or non-
impulsive), likelihood an individual would be exposed for a long enough
duration or to a high enough level to induce a TS, the magnitude of a
TS, time to recover (seconds to minutes or hours to days), the
frequency range of the exposure (i.e., spectral content), the hearing
and vocalization frequency range of the exposed species relative to the
signal's frequency spectrum (i.e., how an animal uses sound within the
frequency band of the signal; e.g., Kalstein et al., 2014), and the
overlap between the animal and the source (e.g., spatial, temporal, and
spectral).
Permanent Threshold Shift (PTS)--NMFS defines PTS as a permanent,
irreversible increase in the threshold of audibility at a specified
frequency or portion of an individual's hearing range above a
previously established reference level (NMFS 2018). Available data from
humans and other terrestrial mammals indicate that a 40 dB threshold
shift approximates PTS onset (see Ward et al., 1958, 1959; Ward 1960;
Kryter et al., 1966; Miller 1974; Henderson et al., 2008). PTS levels
for marine mammals are estimates, as with the exception of a single
study unintentionally inducing PTS in a harbor seal (Kastak et al.,
2008), there are no empirical data measuring PTS in marine mammals
largely due to the fact that, for various ethical reasons, experiments
involving anthropogenic noise exposure at levels inducing PTS are not
typically pursued or authorized (NMFS 2018).
Temporary Threshold Shift (TTS)--TTS is a temporary, reversible
increase in the threshold of audibility at a specified frequency or
portion of an individual's hearing range above a previously established
reference level (NMFS 2018). Based on data from cetacean TTS
measurements (see Southall et al., 2007), a TTS of 6 dB is considered
the minimum threshold shift clearly larger than any day-to-day or
session-to-session variation in a subject's normal hearing ability
(Schlundt et al., 2000; Finneran et al., 2000, 2002). As described in
Finneran (2015), marine mammal studies have shown the amount of TTS
increases with cumulative sound exposure level (SELcum) in an
accelerating fashion: At low exposures with lower SELcum, the amount of
TTS is typically small and the growth curves have shallow slopes. At
exposures with higher SELcum, the growth curves become steeper and
approach linear relationships with the noise SEL.
Depending on the degree (elevation of threshold in dB), duration
(i.e., recovery time), and frequency range of TTS, and the context in
which it is experienced, TTS can have effects on marine mammals ranging
from discountable to serious (similar to those discussed in auditory
masking, below). For example, a marine mammal may be able to readily
compensate for a brief, relatively small amount of TTS in a non-
critical frequency range that takes place during a time when the animal
is traveling through the open ocean, where ambient noise is lower and
there are not as many competing sounds present. Alternatively, a larger
amount and longer duration of TTS sustained during a time when
communication is critical for successful mother/calf interactions could
have more serious impacts. We note that reduced hearing sensitivity as
a simple function of aging has been observed in marine mammals, as well
as humans and other taxa (Southall et al., 2007), so we can infer that
strategies exist for coping with this condition to some degree, though
likely not without cost.
Currently, TTS data only exist for four species of cetaceans
(bottlenose dolphin, beluga whale (Delphinapterus leucas), harbor
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis)
and five species of pinnipeds exposed to a limited number of sound
sources (i.e., mostly tones and octave-band noise) in laboratory
settings (Finneran 2015). TTS was not observed in trained spotted
(Phoca largha) and ringed (Pusa hispida) seals exposed to impulsive
noise at levels matching previous predictions of TTS onset (Reichmuth
et al., 2016). In general, harbor seals and harbor porpoises have a
lower TTS onset than other measured pinniped or cetacean species
(Finneran 2015). Additionally, the existing marine mammal TTS data come
from a limited number of individuals within these species. No data are
available on noise-induced hearing loss for mysticetes. For summaries
of data on TTS in marine mammals or for further discussion of TTS onset
thresholds, please see Southall et al., (2007), Finneran and Jenkins
(2012), Finneran (2015), and Table 5 in NMFS (2018). Extracting piles
for this project requires vibratory pile removal, yet removal of only
one pile type would occur at a time. There would also be pauses in pile
removal activities; given these pauses and that any marine mammals in
the ensonified area would likely move through the area and not remain
for extended periods of time, the potential for TS declines.
Behavioral Harassment--Exposure to noise from pile removal also has
the potential to behaviorally disturb marine mammals. Available studies
show wide variation in response to underwater sound; therefore, it is
difficult to predict specifically how any given sound in a particular
instance might affect marine mammals perceiving the signal. If a marine
mammal does react briefly to an underwater sound by changing its
behavior or moving a small distance, the impacts of the change are
unlikely to be significant to the individual, let alone the stock or
population. However, if a sound source displaces marine mammals from an
important feeding or breeding area for a prolonged period, impacts on
individuals and populations could be significant (e.g., Forney et al.,
2017; Lusseau and Bejder 2007; Weilgart 2007).
Disturbance may result in changing durations of surfacing and
dives, number of blows per surfacing, or moving direction and/or speed;
reduced/increased vocal activities;
[[Page 24959]]
changing/cessation of certain behavioral activities (such as
socializing or feeding); visible startle response or aggressive
behavior (such as tail/fluke slapping or jaw clapping); avoidance of
areas where sound sources are located. Pinnipeds may increase their
haul out time, possibly to avoid in-water disturbance (Thorson and
Reyff, 2006). Behavioral responses to sound are highly variable and
context-specific and any reactions depend on numerous intrinsic and
extrinsic factors (e.g., species, state of maturity, experience,
current activity, reproductive state, auditory sensitivity, time of
day), as well as the interplay between factors (e.g., Richardson et
al., 1995; Wartzok et al., 2003; Southall et al., 2007; Weilgart 2007;
Archer et al., 2010). Behavioral reactions can vary not only among
individuals but also within an individual, depending on previous
experience with a sound source, context, and numerous other factors
(Ellison et al., 2012), and can vary depending on characteristics
associated with the sound source (e.g., whether it is moving or
stationary, number of sources, distance from source). Please see
Appendices B-C of Southall et al. (2007) for a review of studies
involving marine mammal behavioral responses to sound.
Disruption of feeding behavior can be difficult to correlate with
anthropogenic sound exposure, so it is usually inferred by observed
displacement from known foraging areas, the appearance of secondary
indicators (e.g., bubble nets or sediment plumes), or changes in dive
behavior. As for other types of behavioral response, the frequency,
duration, and temporal pattern of signal presentation, as well as
differences in species sensitivity, are likely contributing factors to
differences in response in any given circumstance (e.g., Croll et al.,
2001; Nowacek et al., 2004; Madsen et al., 2006; Yazvenko et al.,
2007). A determination of whether foraging disruptions incur fitness
consequences would require information on or estimates of the energetic
requirements of the affected individuals and the relationship between
prey availability, foraging effort and success, and the life history
stage of the animal.
Stress responses--An animal's perception of a threat may be
sufficient to trigger stress responses consisting of some combination
of behavioral responses, autonomic nervous system responses,
neuroendocrine responses, or immune responses (e.g., Seyle 1950; Moberg
2000). In many cases, an animal's first and sometimes most economical
(in terms of energetic costs) response is behavioral avoidance of the
potential stressor. Autonomic nervous system responses to stress
typically involve changes in heart rate, blood pressure, and
gastrointestinal activity. These responses have a relatively short
duration and may or may not have a significant long-term effect on an
animal's fitness.
Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that
are affected by stress--including immune competence, reproduction,
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been
implicated in failed reproduction, altered metabolism, reduced immune
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha
2000). Increases in the circulation of glucocorticoids are also equated
with stress (Romano et al., 2004).
The primary distinction between stress (which is adaptive and does
not normally place an animal at risk) and ``distress'' is the cost of
the response. During a stress response, an animal uses glycogen stores
that can be quickly replenished once the stress is alleviated. In such
circumstances, the cost of the stress response would not pose serious
fitness consequences. However, when an animal does not have sufficient
energy reserves to satisfy the energetic costs of a stress response,
energy resources must be diverted from other functions. This state of
distress will last until the animal replenishes its energetic reserves
sufficient to restore normal function.
Relationships between these physiological mechanisms, animal
behavior, and the costs of stress responses are well studied through
controlled experiments and for both laboratory and free-ranging animals
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003;
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to
exposure to anthropogenic sounds or other stressors and their effects
on marine mammals have also been reviewed (Fair and Becker, 2000;
Romano et al., 2002a) and, more rarely, studied in wild populations
(e.g., Romano et al., 2002b). For example, Rolland et al., (2012) found
that noise reduction from reduced ship traffic in the Bay of Fundy was
associated with decreased stress in North Atlantic right whales. These
and other studies lead to a reasonable expectation that some marine
mammals will experience physiological stress responses upon exposure to
acoustic stressors and that it is possible that some of these would be
classified as ``distress.'' In addition, any animal experiencing TTS
would likely also experience stress responses (NRC 2003), however
distress is an unlikely result of this project based on observations of
marine mammals during previous, similar projects in the area.
Masking--Sound can disrupt behavior through masking, or interfering
with, an animal's ability to detect, recognize, or discriminate between
acoustic signals of interest (e.g., those used for intraspecific
communication and social interactions, prey detection, predator
avoidance, navigation) (Richardson et al., 1995). Masking occurs when
the receipt of a sound is interfered with by another coincident sound
at similar frequencies and at similar or higher intensity, and may
occur whether the sound is natural (e.g., snapping shrimp, wind, waves,
precipitation) or anthropogenic (e.g., pile driving, shipping, sonar,
seismic exploration) in origin. The ability of a noise source to mask
biologically important sounds depends on the characteristics of both
the noise source and the signal of interest (e.g., signal-to-noise
ratio, temporal variability, direction), in relation to each other and
to an animal's hearing abilities (e.g., sensitivity, frequency range,
critical ratios, frequency discrimination, directional discrimination,
age or TTS hearing loss), and existing ambient noise and propagation
conditions. Masking of natural sounds can result when human activities
produce high levels of background sound at frequencies important to
marine mammals. Conversely, if the background level of underwater sound
is high (e.g., on a day with strong wind and high waves), an
anthropogenic sound source would not be detectable as far away as would
be possible under quieter conditions and would itself be masked.
Habituation--Habituation can occur when an animal's response to a
stimulus wanes with repeated exposure, usually in the absence of
unpleasant associated events (Wartzok et al., 2003). Animals are most
likely to habituate to sounds that are predictable and unvarying. The
opposite process is sensitization, when an unpleasant experience leads
to subsequent responses, often in the form of avoidance, at a lower
level of exposure. Behavioral state may affect the type of response.
For example, animals that are resting may show greater behavioral
change in response to disturbing sound levels than animals that are
highly motivated to remain in an area for feeding (Richardson et al.,
1995; NRC 2003; Wartzok et al., 2003). Controlled experiments with
captive
[[Page 24960]]
marine mammals have showed pronounced behavioral reactions, including
avoidance of loud sound sources (Ridgway et al., 1997; Finneran et al.,
2003). Observed responses of wild marine mammals to loud-impulsive
sound sources (typically seismic airguns or acoustic harassment
devices) have been varied but often consist of avoidance behavior or
other behavioral changes suggesting discomfort (Morton and Symonds
2002; see also Richardson et al., 1995; Nowacek et al., 2007). In
general, pinnipeds seem more tolerant of, or at least habituate more
quickly to, potentially disturbing underwater sound than do cetaceans,
and generally seem to be less responsive to exposure to industrial
sound than most cetaceans.
Airborne Acoustic Effects from the Proposed Activities--Pinnipeds
that occur near the project site could be exposed to airborne sounds
associated with pile removal that have the potential to cause
behavioral harassment, depending on their distance from construction
activities. Cetaceans are not expected to be exposed to airborne sounds
that would result in harassment as defined under the MMPA.
Airborne noise will primarily be an issue for pinnipeds that are
swimming or hauled out near the project site within the range of noise
levels elevated above the acoustic criteria. We recognize that
pinnipeds in the water could be exposed to airborne sound that may
result in behavioral harassment when looking with heads above water.
Most likely, airborne sound would cause behavioral responses similar to
those discussed above in relation to underwater sound. However, these
animals would previously have been ``taken'' as a result of exposure to
underwater sound above the behavioral harassment thresholds, which are
in all cases larger than those associated with airborne sound. Multiple
instances of exposure to sound above NMFS' thresholds for behavioral
harassment are not believed to result in increased behavioral
disturbance, in either nature or intensity of disturbance reaction. As
the behavioral harassment of these animals is already accounted for in
these estimates of potential take, effects of airborne noise will not
be considered further.
Marine Mammal Habitat Effects
Chevron's construction activities could have localized temporary
impacts on marine mammal prey and foraging habitat by increasing in-
water sound pressure levels and slightly decreasing water quality.
However, construction activities are of relatively short duration and
the removal of the creosote treated piles of the Wharf will have a
long-term beneficial effect on marine mammal habitat.
Effects on Potential Prey--Sound may affect marine mammals through
impacts on the abundance, behavior, or distribution of prey species
(e.g., fish). Marine mammal prey varies by species, season, and
location. Here, we describe studies regarding the effects of noise on
known marine mammal prey.
Fish utilize the soundscape and components of sound in their
environment to perform important functions such as foraging, predator
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay 2009).
Depending on their hearing anatomy and peripheral sensory structures,
which vary among species, fishes hear sounds using pressure and
particle motion sensitivity capabilities and detect the motion of
surrounding water (Fay et al., 2008). The potential effects of noise on
fishes depends on the overlapping frequency range, distance from the
sound source, water depth of exposure, and species-specific hearing
sensitivity, anatomy, and physiology. Key impacts to fishes may include
behavioral responses, hearing damage, barotrauma (pressure-related
injuries), and mortality.
Fish react to sounds which are especially strong and/or
intermittent low-frequency sounds, and behavioral responses such as
flight or avoidance are the most likely effects. The reaction of fish
to noise depends on the physiological state of the fish, past
exposures, motivation (e.g., feeding, spawning, migration), and other
environmental factors. Hastings and Popper (2005) identified several
studies that suggest fish may relocate to avoid certain areas of sound
energy. However, some studies have shown no or slight reaction to
impulse sounds (e.g., Pena et al., 2013; Jorgenson and Gyselman, 2009;
Cott et al., 2012).
SPLs of sufficient strength have been known to cause injury to fish
and fish mortality. However, in most fish species, hair cells in the
ear continuously regenerate and loss of auditory function likely is
restored when damaged cells are replaced with new cells. Halvorsen et
al., (2012a) showed that a TTS of 4-6 dB was recoverable within 24
hours for one species. Impacts would be most severe when the individual
fish is close to the source and when the duration of exposure is long.
Injury caused by barotrauma can range from slight to severe and can
cause death, and is most likely for fish with swim bladders. Barotrauma
injuries have been documented during controlled exposure to impact pile
driving (Halvorsen et al., 2012b; Casper et al., 2013).
The most likely impact to fish from pile removal activities at the
project area would be temporary behavioral avoidance of the area. The
duration of fish avoidance of an area after pile removal stops is
unknown, but a rapid return to normal recruitment, distribution and
behavior is anticipated. In addition, the affected area represents an
extremely small portion of the total foraging area available to marine
mammals within San Francisco Bay.
Effects on Potential Foraging Habitat--A temporary, small-scale
loss of foraging habitat may occur for marine mammals if marine mammals
avoid the area during Wharf demolition. Pile removal may temporarily
impact foraging habitat by increasing turbidity resulting from
suspended sediments. Impacts to benthic invertebrate species would be
primarily associated with disturbance of sediments that may cover or
displace some invertebrates. The impacts will be highly localized, and
no habitat will be permanently displaced by construction activities. As
previously noted, the affected area represents a small portion of the
total area within foraging range of marine mammals that may be present.
Therefore, it is expected that impacts on foraging opportunities for
marine mammals due to the removal of the Point Orient Wharf would be
minimal.
Estimated Take
This section provides an estimate of the number of incidental takes
proposed for authorization through these IHAs, which will inform both
NMFS' consideration of ``small numbers'' and the negligible impact
determination.
Harassment is the only type of take expected to result from these
activities. Except with respect to certain activities not pertinent
here, section 3(18) of the MMPA defines ``harassment'' as any act of
pursuit, torment, or annoyance, which (i) has the potential to injure a
marine mammal or marine mammal stock in the wild (Level A harassment);
or (ii) has the potential to disturb a marine mammal or marine mammal
stock in the wild by causing disruption of behavioral patterns,
including, but not limited to, migration, breathing, nursing, breeding,
feeding, or sheltering (Level B harassment).
Authorized takes would primarily be by Level B harassment, as noise
generated from in-water pile removal (vibratory) has the potential to
result in disruption of behavioral patterns for individual marine
mammals. There is also some potential for auditory injury
[[Page 24961]]
(Level A harassment) to result, primarily for high- and low-frequency
species and phocids because predicted auditory injury zones are larger
than for mid-frequency species. However, auditory injury is unlikely to
occur due to the proposed shutdown zones (see Proposed Mitigation
section). Additionally, the proposed mitigation and monitoring measures
are expected to minimize the severity of the taking to the extent
practicable.
As described previously, no mortality is anticipated or proposed to
be authorized for this activity. Below we describe how the take is
estimated.
Generally speaking, we estimate take by considering: (1) Acoustic
thresholds above which NMFS believes the best available science
indicates marine mammals 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 basic
factors can contribute to a basic calculation to provide an initial
prediction of takes, additional information that can qualitatively
inform take estimates is also sometimes available (e.g., previous
monitoring results or average group size). Below, we describe the
factors considered here in more detail and present the proposed take
estimate.
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 PTS of some degree (equated to Level A
harassment). Thresholds have also been developed identifying the
received level of in-air sound above which exposed pinnipeds would
likely be behaviorally harassed.
Level B Harassment for non-explosive sources--Though significantly
driven by received level, the onset of behavioral disturbance from
anthropogenic noise exposure is also informed to varying degrees by
other factors related to the source (e.g., frequency, predictability,
duty cycle), the environment (e.g., bathymetry), and the receiving
animals (hearing, motivation, experience, demography, behavioral
context) and can be difficult to predict (Southall et al., 2007,
Ellison et al., 2012). Based on what the available science indicates
and the practical need to use a threshold based on a factor that is
both predictable and measurable for most activities, NMFS uses a
generalized acoustic threshold based on received level to estimate the
onset of behavioral harassment. NMFS predicts that marine mammals are
likely to be behaviorally harassed in a manner we consider Level B
harassment when exposed to underwater anthropogenic noise above
received levels of 120 dB re 1 micropascal ([mu]Pa) root mean square
(rms) for continuous (e.g., vibratory pile-driving, drilling) and above
160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., seismic
airguns) or intermittent (e.g., scientific sonar) sources.
Chevron's Point Orient Wharf Removal includes the use of continuous
non-impulsive (vibratory pile removal) sources, and therefore the 120
dB re 1 [mu]Pa (rms) is applicable.
Level A harassment for non-explosive sources--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 Point Orient Wharf Removal
includes the use of non-impulsive vibratory pile removal.
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 4--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: 1183 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: 1185 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: 1185 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 will feed into identifying the area ensonified above the
acoustic thresholds, which include source levels and transmission loss
coefficient.
Pile extraction using a vibratory hammer will generate underwater
noise that potentially 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 vibratory pile extraction for each pile type. Vibratory pile
extraction (and if not available,
[[Page 24962]]
vibratory driving) sound from similar type and sized piles have been
measured from other projects and can be used to estimate the noise
levels that this project would generate. This analysis uses the
practical spreading loss model, a standard assumption regarding sound
propagation for similar environments, to estimate transmission of sound
through water. For this analysis, the transmission loss factor of 15
(4.5 dB per doubling of distance) is used. A weighting adjustment
factor of 2.5, a standard default value for vibratory pile driving and
removal, was used to calculate Level A harassment areas.
Pile extraction will include the removal of existing 12-inch timber
piles during Year 1 and Year 2, and the removal of various sizes of
steel piles during Year 2. Approximately 543 timber piles would be
removed in Year 1 and 376 timber piles in Year 2. Of the timber piles
in Year 1, 133 piles are encased in concrete, however, since the
concrete wrapping is only present on the upper portion of the pile,
these piles are expected to behave as the unwrapped timber piles in
regards to generation of underwater noise. Although some piles may be
extracted with direct pulling, this analysis assumes that a vibratory
pile driver will be used to remove all piles. Up to 18 of the unwrapped
piles or 11 of the wrapped piles could be extracted in one work day,
but on most days a co-mingling of the two types would likely be
removed. Vibratory extraction time needed for each pile could require
approximately 6 minutes for each of the unwrapped piles and 9 minutes
for each of the concrete wrapped piles (Table 1). An estimated 35 work
days will be spent in Year 1 removing timber piles and approximately 27
work days will be spent removing timber piles in Year 2 (Table 1). The
most applicable noise values for timber pile removal from which to base
estimates for the proposed project are the values used for the Pier 62/
63 pile removal in Seattle, Washington (City of Seattle 2017). During
vibratory pile extraction associated with this project, the RMS was
estimated to be approximately 152 dB at a distance of 10 meters (City
of Seattle, 2017) (Table 5).
In Year 2, 34 36-inch steel piles will be extracted. Each 36-inch
steel pipe pile may require approximately 45 minutes of vibratory
extraction for removal. Up to two of these piles could be removed in a
single work day (Table 1). Chevron is planning a total of 18 work days
to remove the 36-inch steel piles (Table 1). Installation of this pile
type was hydro-acoustically monitored during the CLWMEP in 2019 (AECOM
2020). As pile installation typically produces more sound than
vibratory removal, the sound levels during vibratory extraction in this
project are expected to be equal to or less than the maximum sound
levels recorded during that installation. The maximum measured peak
sound value was 196 dB measured at 10 meters, and the highest median
RMS value recorded was 167 dB measured at 15 meters (AECOM 2020) (Table
5).
Approximately 40 30-inch steel piles would also be removed in Year
2. Each 30-inch steel pipe pile may require approximately 32 minutes of
vibratory extraction for removal. Up to three of these piles could be
removed in a single work day (Table 1). Chevron has planned
approximately 10 work days to remove the 30-inch steel piles (Table 1).
Installation of this pile type was hydro-acoustically monitored at the
WETA Downtown Ferry Terminal in San Francisco, CA (Caltrans 2020). The
sound levels during vibratory extraction are expected to be equal to or
less than the maximum sound levels recorded during that installation.
The maximum measured peak sound value was 183 dB measured at 7 meters,
and the highest median rms value recorded was 156 dB measured at 7
meters (Caltrans 2020) (Table 5).
In Year 2, approximately 16 24-inch steel piles would be removed.
Each 24-inch steel pile may require up to 26 minutes of vibration to
remove (Table 1). Chevron has planned approximately 6 work days to
remove the 24-inch steel piles (Table 1). Installation of this pile
type was hydro-acoustically monitored at the WETA Downtown Ferry
Terminal in San Francisco, CA (Caltrans 2020). The sound levels during
vibratory extraction are expected to be equal to or less than the
maximum sound levels recorded during that installation. For the 24-inch
piles, the maximum measured peak sound value was 178 dB measured at 15
meters, and the highest median RMS value recorded was 157 dB measured
at 15 meters (Caltrans 2020) (Table 5).
Table 5--Source Levels for Vibratory Removal of Piles for Year 1 and Year 2
----------------------------------------------------------------------------------------------------------------
Source levels/source distance
(m)
Pile type Diameter (in) -------------------------------
Peak RMS
----------------------------------------------------------------------------------------------------------------
Year 1
----------------------------------------------------------------------------------------------------------------
Timber.......................................................... 12 NA 152/10
----------------------------------------------------------------------------------------------------------------
Year 2
----------------------------------------------------------------------------------------------------------------
Timber.......................................................... 12 NA 152/10
Steel........................................................... 36 196/10 167/15
Steel........................................................... 30 183/7 156/7
Steel........................................................... 24 178/15 157/15
----------------------------------------------------------------------------------------------------------------
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 vibratory pile removal),
[[Page 24963]]
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. Inputs used in the User
Spreadsheet are reported in Table 1 and source levels used in the
spreadsheet are reported in Table 5. The resulting Level A and Level B
harassment isopleths as well as area encompassed by the Level B
harassment isopleths are reported below in Table 6.
Table 6--Level A and Level B Harassment Isopleths by Pile Type
----------------------------------------------------------------------------------------------------------------
Hearing group
------------------------------------------------------------ Level B
Level A isopleths (m) Level B isopleth
Pile type ------------------------------------------------------------ isopleths area
LF MF HF Phocid Otariid (m) (km\2\)
cetaceans cetaceans cetaceans pinnipeds pinnipeds
----------------------------------------------------------------------------------------------------------------
Timber...................... 3 1 4 2 1 1,359 3.81
36'' steel.................. 34 3 50 21 2 20,390 26.93
30'' steel.................. 3 1 5 2 1 1,758 0.93
24'' steel.................. 8 1 12 5 1 4,393 5.14
----------------------------------------------------------------------------------------------------------------
The maximum distance to the Level A harassment threshold during
construction would be during the vibratory removal of the 36 inch steel
piles during Year 2 (34 m for gray whales, 3 m for bottlenose dolphins,
50 m for harbor porpoises, 21 m for harbor seals, and 2 m for sea
lions). The largest Level B harassment zone extends out to 20,390 m for
extraction of the 36 inch steel piles. Area was calculated for each
Level B harassment isopleth through a GIS exercise and incorporated
into take calculations for California sea lions and harbor porpoises
(see below).
Marine Mammal Occurrence and Take Estimation and Calculation
In this section we provide the information about the presence,
density, or group dynamics of marine mammals that will inform the take
calculations. We will also describe how this information is brought
together to produce a quantitative take estimate for each species.
Harbor Seals
Limited at-sea densities are available for Pacific harbor seals in
San Francisco Bay. To estimate the number of harbor seals potentially
exposed to Level B harassment, take estimates were developed based upon
annual surveys of haul outs in San Francisco 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, haul out counts may provide
accurate estimates of harbor seals in the area during that time. Due to
the close proximity of Castro Rocks to the project area, haul out
occupancy of Castro Rocks was selected to determine take estimates.
Calculations of take estimates were based upon the highest mean value
of harbor seals observed 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 (Table 7).
Based upon radio and telemetry data in San Francisco Bay, it is
expected that harbor seals concentrate within 10 m of Castro Rocks in
all directions while foraging (Grigg et al., 2012). Due to the close
proximity of the project area to Castro Rocks, it is expected that all
seals assumed to be present (237) on a given day would enter the Level
B harassment zone during steel pile extraction and half of the seals
(119) would enter the Level B harassment zone during timber pile
extraction. Chevron is requesting authorization of a total of 4,165
takes of harbor seals by Level B harassment across the 35 planned work
days in Year 1 (Table 8). In Year 2, Chevron is requesting
authorization of a total of 11,271 takes of harbor seals by Level B
harassment across the 61 planned work days (Table 9).
Chevron plans to implement shutdown zones based upon the distances
to the Level A threshold for each hearing group (Table 6). Therefore,
takes of harbor seals by Level A harassment were not requested, nor are
takes by Level A harassment proposed for authorization by NMFS.
California Sea Lions
Although there are no haul out sites for California sea lions in
close proximity to the Wharf, sea lions have consistently been sighted
in San Francisco Bay while monitoring during past construction projects
(AECOM 2019, 2020; Caltrans 2017). During a long-term monitoring effort
for the demolition and reuse of the original east span of the San
Francisco-Oakland Bay Bridge in the central Bay, 83 California sea
lions were observed in the vicinity of the bridge over a 17-year period
(2000 to 2017) (Caltrans 2017). In order to calculate the estimated at-
sea density of sea lions, the number of sea lions observed over the 17
year period (83 animals) was divided by the number of monitoring days
(257 days) to find the number of sea lions observed per day. The total
number of sea lions observed per day was then divided by the area of
the monitoring zone (2 km\2\) to derive an estimated at-sea density of
0.16 animals per square kilometer (Caltrans 2017) (Table 7). In order
to calculate a daily take estimate for the current Wharf removal
project, sea lion density was multiplied by the area of the Level B
harassment zone for each pile type (Tables 6). The daily take estimate
was then multiplied by the number of work days for that pile type to
receive a total take estimate per year (Tables 1, 8, 9). Chevron is
requesting authorization of a total of 22 takes of California sea lions
by Level B harassment in Year 1, and a total of 542 takes of California
sea lions by Level B harassment in Year 2 (Tables 8, 9).
Level A harassment takes of California sea lions were not requested
by Chevron, nor with they be authorized by NMFS. As Chevron plans to
implement a shutdown zone for all Level A harassment isopleths for each
hearing group, Level A harassment takes are not expected.
Harbor Porpoise
The harbor porpoise population has been growing over time in San
Francisco Bay (Stern et al., 2017). Although commonly sighted in the
vicinity of Angel Island and the Golden Gate, approximately 6 and 12
kilometers (3.7 and 7.5 miles, respectively) southwest of the Wharf,
individuals may use other areas of central San
[[Page 24964]]
Francisco Bay (Keener 2011), as well as the project area.
As in the case of California sea lions, density estimates
temporally and spatially aligned with the project work period were
available for harbor porpoises based upon long term monitoring for the
demolition and reuse of the original east span of the San Francisco-
Oakland Bay Bridge in the central Bay (Caltrans 2017). During the 257
days of monitoring from 2000-2017, approximately 24 harbor porpoises
were observed in the bridge vicinity. The total number of harbor
porpoises observed per day was calculated by dividing the total number
of harbor porpoises observed by the number of monitoring days. This
estimate per day was then divided by the area of the monitoring zone
for harbor porpoises (15 km\2\) to calculate an at-sea density of
harbor porpoises (0.17 harbor porpoises/square kilometer). In order to
calculate a daily take estimate for the current Wharf removal project,
the density of harbor porpoises (0.17) was multiplied by the area of
the Level B harassment zone for each pile type (Table 6). To calculate
a total take estimate of harbor porpoises per year, the daily estimate
was multiplied by the number of anticipated work days for each pile
type (Tables 1, 8, 9). Chevron is requesting authorization of a total
of 23 takes of harbor porpoises by Level B harassment in Year 1 (Table
8), and a total of 576 takes of harbor porpoises by Level B harassment
in Year 2 (Table 9).
Takes of harbor porpoises by Level A harassment are not expected as
Chevron plans to shut down construction activities within the Level A
harassment zones for all pile types and hearing groups. NMFS does not
propose to authorize Level A harassment takes of harbor porpoises, nor
have Level A harassment takes been requested.
Bottlenose Dolphin
Bottlenose dolphins in San Francisco Bay are typically observed
west of Treasure Island, near the Golden Gate at the mouth of the Bay,
and along the nearshore areas of San Francisco south to Redwood City
(Bay Nature Institute 2014; NMFS 2017). The numbers of dolphins in San
Francisco Bay have been increasing over the years (Perlman 2017;
Szczepaniak et al., 2013). Although dolphins may occur in the Bay year-
round, density estimates are limited. Beginning in 2015, two
individuals have been observed frequently in the vicinity of Alameda
(APER 2019; Perlman 2017). The average reported group size for
bottlenose dolphins in this area is five. Assuming a group of five
dolphins comes into San Francisco Bay on two week intervals and
vibratory pile extraction occurs over 6 two-week periods, 30 bottlenose
dolphin takes would be expected if the group enters the area over which
the Level B harassment thresholds may be exceeded (Tables 8, 9).
Chevron is requesting authorization of 30 takes of bottlenose dolphins
by Level B harassment per year (Tables 8, 9).
Takes of bottlenose dolphins by Level A harassment are not
anticipated as Chevron plans to implement a shutdown zone for all Level
A harassment isopleths. Takes of bottlenose dolphins by Level A
harassment were not requested by Chevron nor will they be authorized by
NMFS.
Gray Whale
Gray whales are most often sighted in San Francisco Bay during
February and March, however, Wharf removal is 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, 2020). Limited sightings of gray whales in the
Bay include strandings, (Bartlett 2022; TMMC 2019), monitoring during
work on the RSRB (Winning 2008), and whale watch reports (Bartlett
2022). At-sea densities and regular observational data for gray whales
in San Francisco Bay during the planned project time are not available.
Therefore, take estimates are based upon the potential for one pair of
gray whales to be present in the project area each year. In the event
that gray whales are in the project area during the time of
construction activities, Chevron is requesting authorization for two
gray whale takes by Level B harassment per year (Tables 8, 9).
Takes of gray whales by Level A harassment are not anticipated as
Chevron plans to shut down construction activities within the Level A
harassment zones for all pile types and hearing groups. NMFS does not
plan to authorize any takes by Level A harassment of gray whales, nor
have any takes by Level A harassment been requested.
Northern Elephant Seal
Small numbers of elephant seals may haul out or strand within
central San Francisco Bay (Caltrans 2015; Hern[aacute]ndez 2020).
Previous monitoring, however, has shown northern elephant seal
densities to be very low in the area and out of season for the proposed
Wharf removal project. Additionally, northern elephant seals were not
observed during pile driving monitoring for the CLWMEP from 2018-2020,
which was located just south of the proposed project area. However, as
northern elephant seals have been sighted in the Bay, and on assumption
that an elephant seal enters the Level B harassment zone once every
three days during pile extraction, Chevron is requesting authorization
of a total of 12 takes of elephant seals by Level B harassment during
Year 1 and 21 takes of elephant seals by Level B harassment during Year
2 (Tables 8, 9).
Takes of elephant seals by Level A harassment are not anticipated
as Chevron plans to implement a shutdown zone for all Level A
harassment isopleths. Takes of elephant seals by Level A harassment
were not requested by Chevron nor will they be authorized by NMFS.
Northern Fur Seal
The presence of northern fur seals in San Francisco Bay depends
upon oceanic conditions, as more fur seals are likely to 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, and La Ni[ntilde]a conditions are likely to remain for most of
spring 2022. During summer 2022, La Ni[ntilde]a conditions are expected
to remain or transition into neutral El Ni[ntilde]o conditions (NOAA
2022). Since there are no estimated at-sea densities for this species
in San Francisco Bay, Chevron conservatively requested authorization
for, and NMFS proposes to authorize, 10 takes of fur seals per year by
Level B harassment (Tables 8, 9).
Takes of northern fur seals by Level A harassment are not
anticipated as Chevron plans to shut down construction activities
within the Level A harassment zones for all pile types and hearing
groups. NMFS does not plan to authorize takes of northern fur seals by
Level A harassment, nor have takes by Level A harassment been
requested.
[[Page 24965]]
Table 7--Estimated Marine Mammal Densities and Occurrences
----------------------------------------------------------------------------------------------------------------
Estimated density/
Species Stock occurrence References
----------------------------------------------------------------------------------------------------------------
Harbor Seals......................... California............. 237 per day in June- (Codde and Allen 2013,
July (molt season). 2015, 2017, 2020;
Codde 2020).
California Sea Lions................. U.S.................... 0.16 animals/km\2\..... (Caltrans 2017).
Harbor Porpoise...................... SF-Russian River....... 0.17 animals/km\2\..... (Caltrans 2017).
Bottlenose Dolphin................... CA Coastal............. Average group size of 5 (APER 2019; Perlman
present in the Bay in 2017).
two week intervals.
Gray Whale........................... Eastern N Pacific...... Rare; 2 whales per year (TMMC 2019; Winning
2008).
Northern Elephant Seal............... CA Breeding............ Rare; once every 3 days (Caltrans 2015;
Hern[aacute]ndez
2020).
Northern Fur Seal.................... California............. Rare; 10 seals per year (TMMC 2016).
----------------------------------------------------------------------------------------------------------------
Table 8--Proposed Authorized Amount of Marine Mammal Level B Takes by Species and Stock, and Percent of Takes by
Stock Year 1
----------------------------------------------------------------------------------------------------------------
Requested Percent of
Species Stock Pile type/size total take stock
----------------------------------------------------------------------------------------------------------------
Harbor Seals..................... California *....... timber 12''............. * 4,165 * 13.4
California Sea Lions............. U.S................ timber 12''............. 22 <0.01
Harbor Porpoise.................. San Francisco- timber 12''............. 23 0.3
Russian River.
Bottlenose Dolphin............... CA Coastal......... timber 12''............. 30 6.6
Gray Whale....................... Eastern North timber 12''............. 2 <0.01
Pacific.
Northern Elephant Seal........... California Breeding timber 12''............. 12 <0.01
Northern Fur Seal................ California......... timber 12''............. 10 0.07
----------------------------------------------------------------------------------------------------------------
* Assumes multiple repeated takes of the same individuals from a small portion of the stock. Please see the
small numbers section for additional information.
Abundance estimates are taken from the 2020 U.S. Pacific Marine Mammal Stock Assessments (Carretta et al.,
2021).
Table 9--Proposed Authorized Amount of Marine Mammal Level B Takes by Species and Stock, and Percent of Takes by
Stock Year 2
----------------------------------------------------------------------------------------------------------------
Requested Percent of
Species Stock Pile type/size total take stock
----------------------------------------------------------------------------------------------------------------
Harbor Seals..................... California *....... timber 12''............. 3,213 ..............
steel 36''.............. 4,266 ..............
steel 30''.............. 2,370 ..............
steel 24''.............. 1,422 ..............
------------------------------------------------------------------------------
Total........................ ................... ........................ * 11,271 * 36.4
California Sea Lions............. U.S................ timber 12''............. 17 ..............
steel 36''.............. 485 ..............
steel 30''.............. 9 ..............
steel 24''.............. 31 ..............
------------------------------------------------------------------------------
Total........................ ................... ........................ 542 1.3
Harbor Porpoise.................. San Francisco- timber 12''............. 18 ..............
Russian River.
steel 36''.............. 515 ..............
steel 30''.............. 10 ..............
steel 24''.............. 33 ..............
------------------------------------------------------------------------------
Total........................ ................... ........................ 576 7.4
Bottlenose Dolphin............... California Coastal. ........................ 30 6.6
Gray Whale....................... Eastern North ........................ 2 <0.01
Pacific.
Northern Elephant Seal........... California Breeding ........................ 21 0.01
Northern Fur Seal................ California......... ........................ 10 0.07
----------------------------------------------------------------------------------------------------------------
* Assumes multiple repeated takes of the same individuals from a small portion of the stock. Please see the
small numbers section for additional information.
Abundance estimates are taken from the 2020 U.S. Pacific Marine Mammal Stock Assessments (Carretta et al.,
2021).
Proposed 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. 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)).
[[Page 24966]]
In evaluating how mitigation may or may not be appropriate to
ensure the least practicable adverse impact on species or stocks and
their habitat, as well as subsistence uses where applicable, we
carefully consider two primary factors:
(1) The manner in which, and the degree to which, the successful
implementation of the measure(s) is expected to reduce impacts to
marine mammals, marine mammal species or stocks, and their habitat.
This considers the nature of the potential adverse impact being
mitigated (likelihood, scope, range). It further considers the
likelihood that the measure will be effective if implemented
(probability of accomplishing the mitigating result if implemented as
planned), the likelihood of effective implementation (probability
implemented as planned), and;
(2) The practicability of the measures for applicant
implementation, which may consider such things as cost, impact on
operations, and, in the case of a military readiness activity,
personnel safety, practicality of implementation, and impact on the
effectiveness of the military readiness activity.
Mitigation for Marine Mammals and Their Habitat
The following mitigation measures are proposed for Chevron's
removal of the Point Orient Wharf:
<bullet> Time restriction: For all in-water pile removal
activities, Chevron shall operate only when the shutdown zone is
visible and visual monitoring of marine mammals can be conducted;
<bullet> Establishment of shutdown zones: As proposed by Chevron,
shutdown zones will be established for each pile type to include the
Level A harassment zone for each hearing group. The Level A harassment
zone encompasses all of the area where underwater sound pressure levels
are expected to reach or exceed the cumulative SEL thresholds for Level
A harassment (Table 6), and will be no less than 10 m. The radii of the
shutdown zones are rounded to the next largest 5 m interval if the
value is greater than 10 m; and
<bullet> PSOs: Trained PSOs will conduct visual monitoring from
clear, elevated vantage points, along the shoreline or construction
barges, where the entirety of the shutdown zones can be observed. PSOs
will monitor the shutdown zones for 30 minutes prior to any pile
extraction activity to be sure marine mammals are not in the zones.
Pile extraction will not commence until marine mammals have not been
sighted within the shutdown zone for 30 minutes. If a marine mammal is
observed entering a shutdown zone during pile extraction, construction
activities will stop until the marine mammal leaves the zone, and will
not resume until no marine mammals are observed in the shutdown zone
for 30 minutes. If a marine mammal is seen above water and dives below,
a 15 minute wait period will begin. If the marine mammal is not
redetected in that time, it will be assumed that the marine mammal has
moved beyond the shutdown zone, and construction activities will
continue.
Based on our evaluation of the applicant's proposed measures, NMFS
has preliminarily determined that the proposed 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.
Proposed Monitoring and Reporting
In order to issue an IHA for an activity, section 101(a)(5)(D) of
the MMPA states that NMFS must set forth requirements pertaining to the
monitoring and reporting of such taking. The MMPA implementing
regulations at 50 CFR 216.104(a)(13) indicate that requests for
authorizations must include the suggested means of accomplishing the
necessary monitoring and reporting that will result in increased
knowledge of the species and of the level of taking or impacts on
populations of marine mammals that are expected to be present in the
proposed action area. Effective reporting is critical both to
compliance as well as ensuring that the most value is obtained from the
required monitoring.
Monitoring and reporting requirements prescribed by NMFS should
contribute to improved understanding of one or more of the following:
<bullet> Occurrence of marine mammal species or stocks in the area
in which take is anticipated (e.g., presence, abundance, distribution,
density).
<bullet> Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
affected species (e.g., life history, dive patterns); (3) co-occurrence
of marine mammal species with the action; or (4) biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
<bullet> Individual marine mammal responses (behavioral or
physiological) to acoustic stressors (acute, chronic, or cumulative),
other stressors, or cumulative impacts from multiple stressors.
<bullet> How anticipated responses to stressors impact either: (1)
Long-term fitness and survival of individual marine mammals; or (2)
populations, species, or stocks.
<bullet> Effects on marine mammal habitat (e.g., marine mammal prey
species, acoustic habitat, or other important physical components of
marine mammal habitat).
<bullet> Mitigation and monitoring effectiveness.
Chevron will monitor to collect sighting data and record behavioral
responses to construction activities for all marine mammal species
observed in the project location during the period of activity. The
monitoring zone will include all shutdown zones and areas where
underwater sound pressure levels are expected to reach or exceed the
thresholds for Level B harassment. Monitoring will be conducted by
qualified protected species observers (PSOs), trained biologists
familiar with marine mammal species and their behavior.
Chevron will monitor the shutdown zones and monitoring zones
before, during, and after pile removal activities with at least two
PSOs located at the best practicable vantage points. Based upon our
requirements, the Marine Mammal Monitoring Plan would implement the
following procedures for pile removal:
<bullet> PSOs must be independent observers (i.e., not construction
personnel). All PSOs must have the ability to conduct field
observations and collect data according to assigned protocols, be
experienced in field identification of marine mammals and their
behaviors, and submit their resumes to NMFS for approval;
<bullet> Biological monitoring will occur within one week of the
project's start date to establish baseline observation;
<bullet> Observation periods will encompass different tide levels
at different hours of the day;
<bullet> Monitoring will occur from elevated locations along the
shoreline or on barges where the entire shutdown zones and monitoring
zones are visible. If visibility decreases, such as due to fog or
weather, vibratory pile extraction would be stopped until PSOs are able
to view the entire shutdown zone;
<bullet> PSOs will be equipped with high quality binoculars for
monitoring and radios or cells phones for maintaining contact with work
crews;
[[Page 24967]]
<bullet> PSOs will implement clearing of the shutdown and
monitoring zones as well as shutdown procedures; and
<bullet> At the end of the pile removal day, post-construction
monitoring will be conducted for 30 minutes beyond the cessation of
pile removal.
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 removal activities to marine
mammals;
<bullet> Record of 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 Measures
Chevron shall submit a draft report to NMFS within 90 days of the
completion of marine mammal monitoring, or 60 days prior to the
issuance of any subsequent IHA for this project (if required),
whichever comes first. The annual report would detail the monitoring
protocol, summarize the data recorded during monitoring, and estimate
the number of marine mammals that may have been harassed. If no
comments are received from NMFS within 30 days, the draft final report
will become final. If comments are received, a final report must be
submitted up to 30 days after receipt of comments. All PSO datasheets
and/or raw sighting data must be submitted with the draft marine mammal
report.
Reports shall contain the following information:
<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
removed; and (b) the total duration of time for removal of each pile;
<bullet> PSO locations during 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.
Upon observation of a marine mammal, the following information must
be reported:
<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 removal for each sighting;
<bullet> Estimated number of animals by species (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> Detailed information about implementation of any
mitigation (e.g., shutdowns and delays), a description of specified
actions that ensured, and resulting changes in behavior of the
animal(s), if any.
In the unanticipated event that the specified activity clearly
causes the take of a marine mammal in a manner prohibited by the IHA
(if issued), such as an injury (Level A harassment), serious injury or
mortality (e.g., ship-strike, gear interaction, and/or entanglement),
Chevron would immediately cease the specified activities and
immediately report the incident to the Office of Protected Resources
(<a href="/cdn-cgi/l/email-protection#3e6e6c10776a6e10735150574a514c5750596c5b4e514c4a4d7e50515f5f10595148"><span class="__cf_email__" data-cfemail="7525275b3c21255b381a1b1c011a071c1b122710051a070106351b1a14145b121a03">[email protected]</span></a>) and the West Coast Regional
Stranding Coordinator. The report would include the following
information:
<bullet> Time, date, and location (latitude/longitude) of the
incident;
<bullet> Name and type of vessel involved (if applicable);
<bullet> Vessel's speed during and leading up to the incident (if
applicable);
<bullet> Description of the incident;
<bullet> Status of all sound source used in the 24 hours preceding
the incident;
<bullet> Water depth;
<bullet> Environmental conditions (e.g., wind speed and direction,
Beaufort sea state, cloud cover, and visibility);
<bullet> Description of all marine mammal observations in the 24
hours preceding the incident;
<bullet> Species identification or description of the animal(s)
involved;
<bullet> Fate of the animal(s); and
<bullet> Photographs or video footage of the animal(s) (if
equipment is available).
Activities would not resume until NMFS is able to review the
circumstances of the prohibited take. NMFS would work with Chevron to
determine necessary actions to minimize the likelihood of further
prohibited take and ensure MMPA compliance. Chevron would not be able
to resume their activities until notified by NMFS via letter, email, or
telephone.
In the event that Chevron discovers an injured or dead marine
mammal, and the lead PSO determines that the cause of the injury or
death is unknown and the death is relatively recent (i.e., in less than
a moderate state of decomposition as described in the next paragraph),
Chevron would immediately report the incident to the Office of
Protected Resources, NMFS, and the West Coast Regional Stranding
Coordinator. The report would include the same information identified
in the section above. Activities would be able to continue while NMFS
reviews the circumstances of the incident. NMFS would work with Chevron
to determine whether modifications in the activities are appropriate.
In the event that Chevron discovers an injured or dead marine
mammal, and the lead PSO determines that the injury or death is not
associated with or related to the activities authorized in the IHA
(e.g., previously wounded animal, carcass with moderate to advanced
decomposition, or scavenger damage), Chevron would report the incident
to Office of Protected Resources, NMFS, and West Coast Regional
Stranding Coordinator, within 24 hours of the discovery. Chevron would
provide photographs or video footage (if available) or other
documentation of the stranded animal sighting to NMFS and the Marine
Mammal Stranding Network.
[[Page 24968]]
Pile removal activities would be permitted to continue.
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.
Pile removal activities have the potential to disturb or displace
marine mammals. The proposed project activities may result in take in
the form of Level B harassment from underwater sounds generated by
vibratory pile removal. Potential takes could occur if individuals move
into in the ensonified area when construction activities are underway.
The takes from Level B harassment would be due to potential
behavioral disturbance. No serious injury or mortality is anticipated
for any stocks presented in this analysis given the nature of the
activity and mitigation measures designed to minimize the possibility
of injury. The potential for harassment is minimized through
construction method and the implementation of planned mitigation
strategies (see Proposed Mitigation section).
No marine mammal stocks for which incidental take authorization is
proposed are listed as threatened or endangered under the ESA or
determined to be strategic or depleted under the MMPA. The relatively
low marine mammal density, small shutdown zones, and proposed
monitoring also make injury takes of marine mammals unlikely. The
shutdown zones would be thoroughly monitored before the proposed
vibratory pile removal begins and construction activities would be
postponed if a marine mammal is sighted within the shutdown zone. There
is a high likelihood that marine mammals would be detected by trained
observers under environmental conditions described for the proposed
project. Limiting construction activities to daylight hours will also
increase detectability of marine mammal in the area. Therefore, the
proposed mitigation and monitoring measures are expected to eliminate
the potential for injury and Level A harassment as well as reduce the
amount and intensity for Level B behavioral harassment. Furthermore,
the pile removal activities analyzed here are similar to, or less
impactful than, numerous construction activities conducted in other
similar locations which have occurred with no reported injuries or
mortality to marine mammals, and no known long-term adverse
consequences from behavioral harassment.
Anticipated and authorized takes are expected to be limited to
short-term Level B harassment (behavioral disturbance) as construction
activities will occur over the course of 12 weeks and removal of each
pile lasts only approximately 6-45 minutes. Effects on individuals
taken by Level B harassment, based upon reports in the literature as
well as monitoring from other similar activities, may include increased
swimming speeds, increased surfacing time, or decreased foraging (e.g.,
Thorson and Reyff 2006). Individual animals, even if taken multiple
times, will likely move away from the sound source and be temporarily
displaced from the area due to elevated noise level during pile
removal. Marine mammals could also experience TTS if they move into the
Level B monitoring zone. TTS is a temporary loss of hearing sensitivity
when exposed to loud sound, and the hearing threshold is expected to
recover completely within minutes to hours. Thus, it is not considered
an injury. While TTS could occur, it is not considered a likely outcome
of this activity. Repeated exposures of individuals to levels of sounds
that could cause Level B harassment are unlikely to considerably
significantly disrupt foraging behavior or result in significant
decrease in fitness, reproduction, or survival for the affected
individuals. In all, there would be no adverse impacts to the stock as
a whole.
As previously described, a UME has been declared for Eastern
Pacific gray whales. However, we do not expected proposed takes for
authorization in this action to exacerbate the ongoing UME. As
mentioned previously, no injury or mortality is proposed for
authorization, and Level B harassment takes of gray whales will be
reduced to the level of least practicable adverse impact through
incorporation of the proposed mitigation measures. Given that only 2
takes by Level B harassment are proposed for this stock annually, we do
not expect the proposed take authorization to compound the ongoing UME.
The proposed project is not expected to have significant adverse
effects on marine mammal habitat. There are no Biologically Important
Areas or ESA-designated habitat within the project area. While EFH for
several fish species does exist in the proposed project area, the
proposed activities would not permanently modify existing marine mammal
habitat. The activities may cause fish to leave the area temporarily.
This could impact marine mammals' foraging opportunities in a limited
portion of the foraging range, however, due to the short duration of
activities and the relatively small area of affected habitat, the
impacts to marine mammal habitat are not expected to cause significant
or long-term negative consequences.
In summary and as described above, the following factors primarily
support our preliminary determination that the impacts resulting from
this activity are not expected to adversely affect the species or stock
through effects on annual rates of recruitment or survival:
<bullet> No mortality is anticipated or authorized;
<bullet> No Level A harassment, including injury or serious injury,
is anticipated or authorized;
[[Page 24969]]
<bullet> Anticipated impacts of Level B harassment include
temporary behavior modifications;
<bullet> Short duration and intermittent nature of in-water
construction activities;
<bullet> The specified activity and associated ensonified areas are
very small relative to the overall habitat ranges of all species and do
not include habitat areas of special significance (Biologically
Important Areas 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;
<bullet> Monitoring reports from similar work in San Francisco Bay
have documented little to no effect on individuals of the same species
impacted by the specified activities.
These factors, in addition to the available body of evidence from
prior similar activities, demonstrate that the potential effects of the
specified activity will have only short-term effects on individuals.
The specified activity is not expected to impact rates of recruitment
or survival, and will therefore not result in population-level impacts.
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 proposed monitoring and
mitigation measures, NMFS preliminarily finds, specific to both the
Year 1 and Year 2 proposed IHAs, that the total marine mammal take from
the proposed activity will have a negligible impact on all affected
marine mammal species or stocks.
Small Numbers
As noted above, only small numbers of incidental take may be
authorized under sections 101(a)(5)(A) and (D) of the MMPA for
specified activities other than military readiness activities. The MMPA
does not define small numbers and so, in practice, where estimated
numbers are available, NMFS compares the number of individuals taken to
the most appropriate estimation of abundance of the relevant species or
stock in our determination of whether an authorization is limited to
small numbers of marine mammals. When the predicted number of
individuals to be taken is fewer than one third of the species or stock
abundance, the take is considered to be of small numbers. Additionally,
other qualitative factors may be considered in the analysis, such as
the temporal or spatial scale of the activities.
The amount of take NMFS proposes to authorize in Year 1 is below
one-third of the estimated stock abundance for all impacted stocks
(Table 8). The number of animals authorized to be taken during Year 1
would be considered small relative to the relevant stocks or
populations, even if each estimated take occurred to a new individual.
Furthermore, these takes are likely to only occur within a small
portion of the overall regional stock and the likelihood that each take
would occur to a new individual is low.
The amount of take NMFS proposes to authorize in Year 2 is below
one-third of the estimated stock abundance for California sea lions,
harbor porpoises, bottlenose dolphins, gray whales, northern elephant
seals, and northern fur seals (Table 9). The take percentage of the
estimated stock of harbor seals is approximately 36.4 percent, however,
take estimates are likely conservative as they assume all takes are of
different individuals which is likely not the case. Some individuals
may return to the area multiple times a week, but PSOs would count them
as separate takes if they are not individually identified. Therefore,
since take estimates likely include repeated takes of the same
individuals over time, take estimates are expected to represent a
smaller percentage of the total stock. Furthermore, the project area
represents a small portion of the overall range of harbor seals and
activities are will most likely to impact only a small portion of the
stock.
Based on the analysis contained herein of the proposed activity
(including the proposed mitigation and monitoring measures) and the
anticipated take of marine mammals, NMFS preliminarily finds, specific
to both the Year 1 and Year 2 proposed IHAs 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 proposed for
authorization 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.
Proposed Authorization
As a result of these preliminary determinations, NMFS proposes to
issue two consecutive IHAs to Chevron for conducting the Point Orient
Wharf Removal in San Francisco Bay, CA from June 1-November 30, 2022
and June 1-November 30, 2023, provided the previously mentioned
mitigation, monitoring, and reporting requirements are incorporated.
Drafts of the proposed IHAs can be found at <a href="https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act">https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act</a>.
Request for Public Comments
We request comment on our analyses, the proposed authorizations,
and any other aspect of this notice of proposed IHAs for the proposed
Point Orient Wharf Removal. We also request at this time comment on the
potential renewal of this proposed IHAs as described in the paragraph
below. Please include with your comments any supporting data or
literature citations to help inform decisions on the request for these
IHAs or subsequent Renewal IHAs.
On a case-by-case basis, NMFS may issue a one-time, one-year
Renewal IHA following notice to the public providing an additional 15
days for public comments when (1) up to another year of identical or
nearly identical activities as described in the Description of Proposed
Activities section of this notice is planned or (2) the activities as
described in the Description of Proposed Activities section of this
notice would not be completed by the time the IHA expires and a renewal
would allow for completion of the activities beyond that described in
the Dates and Duration section of this notice, provided all of the
following conditions are met:
<bullet> A request for renewal is received no later than 60 days
prior to the needed Renewal IHA effective date (recognizing
[[Page 24970]]
that the Renewal IHA expiration date cannot extend beyond 1 year from
expiration of the initial IHA).
<bullet> The request for renewal must include the following:
(1) An explanation that the activities to be conducted under the
requested Renewal IHA are identical to the activities analyzed under
the initial IHA, are a subset of the activities, or include changes so
minor (e.g., reduction in pile size) that the changes do not affect the
previous analyses, mitigation and monitoring requirements, or take
estimates (with the exception of reducing the type or amount of take).
(2) A preliminary monitoring report showing the results of the
required monitoring to date and an explanation showing that the
monitoring results do not indicate impacts of a scale or nature not
previously analyzed or authorized.
Upon review of the request for renewal, the status of the affected
species or stocks, and any other pertinent information, NMFS determines
that there are no more than minor changes in the activities, the
mitigation and monitoring measures will remain the same and
appropriate, and the findings in the initial IHA remain valid.
Dated: April 21, 2022.
Catherine Marzin,
Deputy Director, Office of Protected Resources, National Marine
Fisheries Service.
[FR Doc. 2022-08888 Filed 4-26-22; 8:45 am]
BILLING CODE 3510-22-P
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This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.