[Federal Register Volume 87, Number 81 (Wednesday, April 27, 2022)]
[Notices]
[Pages 24950-24970]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[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 
www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act 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: https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act. 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).
----------------------------------------------------------------------------------------------------------------
                                           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; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and more general information about these species 
(e.g., physical and behavioral descriptions) may be found on NMFS's 
website (https://www.fisheries.noaa.gov/find-species).
    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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

                                               Table 2--Marine Mammals Likely To Occur in the Project Area
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                                                                                         ESA/ MMPA status;   Stock abundance  (CV,
             Common name                  Scientific name               Stock            strategic  (Y/N)      Nmin, most recent       PBR     Annual  M/
                                                                                                \1\          abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          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)
--------------------------------------------------------------------------------------------------------------------------------------------------------
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).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         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).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\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: www.nmfs.noaa.gov/pr/sars/. 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 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.

                     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 https://www.fisheries.noaa.gov/permit/incidental-take-authorizations-under-marine-mammal-protection-act.

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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