Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to Treasure Island Ferry Dock Project, San Francisco, California, 35271-35292 [2020-12363]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 85, Number 111 (Tuesday, June 9, 2020)]
[Notices]
[Pages 35271-35292]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-12363]



[[Page 35271]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[RTID 0648-XA180]


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to Treasure Island Ferry Dock Project, 
San Francisco, California

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and 
Atmospheric Administration (NOAA), Commerce.

ACTION: Notice; proposed incidental harassment authorization; request 
for comments on proposed authorization and possible renewal.

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SUMMARY: NMFS has received a request from the City and County of San 
Francisco, CA (San Francisco) for authorization to take marine mammals 
incidental to the Treasure Island Ferry Dock Project in San Francisco, 
California. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS 
is requesting comments on its proposal to issue an incidental 
harassment authorization (IHA) to incidentally take marine mammals 
during the specified activities. NMFS is also requesting comments on a 
possible one-year renewal that could be issued under certain 
circumstances and if all requirements are met, as described in Request 
for Public Comments at the end of this notice. NMFS will consider 
public comments prior to making any final decision on the issuance of 
the requested MMPA authorizations and agency responses will be 
summarized in the final notice of our decision.

DATES: Comments and information must be received no later than July 9, 
2020.

ADDRESSES: Comments should be addressed to Jolie Harrison, Chief, 
Permits and Conservation Division, Office of Protected Resources, 
National Marine Fisheries Service. Physical comments should be sent to 
1315 East-West Highway, Silver Spring, MD 20910 and electronic comments 
should be sent to [email protected].
    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 received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://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: Dwayne Meadows, Ph.D., 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 issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be 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 IHA 
qualifies 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 request.

Summary of Request

    On February 6, 2020, NMFS received an application from San 
Francisco requesting an IHA to take small numbers of seven species of 
marine mammals incidental to pile driving associated with the Treasure 
Island Ferry Dock Project. The application was deemed adequate and 
complete on May 13, 2020. San Francisco's request is for take of a 
small number of seven species of marine mammals by Level B harassment 
and Level A harassment. Neither San Francisco nor NMFS expects serious 
injury or mortality to result from this activity and, therefore, an IHA 
is appropriate.

Description of Proposed Activity

Overview

    The project consists of the construction of a ferry terminal, 
breakwater, fireboat access pier, and removal of an old pier on 
Treasure Island in the middle of San Francisco Bay. San Francisco would 
install and then remove two temporary 36-inch-diameter steel piles for 
moorings and 186 temporary 14-inch by 89 foot steel H piles as 
templates. Final construction requires installation of nine 36-inch-
diameter steel piles, five 48-inch-diameter steel piles, 52 24-inch 
octagonal concrete breakwater piles, and 120 14-inch by 89 foot steel H 
piles for the breakwater. Removing the old pier

[[Page 35272]]

requires removal of 198 12-inch diameter timber piles. Pile driving/
removal is expected to take no more than 1,890 hours over 189 days. 
Pile driving would be by vibratory pile driving until resistance is too 
great and driving would switch to an impact hammer. Removal of 
temporary piles would use vibratory methods only.
    The pile driving/removal can result in take of marine mammals from 
sound in the water which results in behavioral harassment or auditory 
injury.

Dates and Duration

    The work described here is scheduled for June 8, 2020 through 
January 15, 2021. California Department of Fish and Wildlife (CDFW) 
regulates activities in San Francisco Bay with the potential to affect 
Pacific herring (Clupea pallasi) breeding, and special work windows 
have been established to avoid potential impacts to Pacific herring 
spawning activities. From November 30th through January 15, 2021, a 
biological monitor trained by CFDW to monitor Pacific herring must be 
present on site during pile installation. If a herring spawning event 
is observed, work will cease for a period of two weeks following the 
spawning event. The area must be surveyed by the biological monitor 
prior to resumption of work. This measure is anticipated to avoid 
impacts to marine mammal prey species within the project area. San 
Francisco has proposed the daily construction window for pile removal 
and driving would begin no sooner than 30 minutes after sunrise and 
would end 30 minutes prior to sunset to allow for marine mammal 
monitoring.

Specific Geographic Region

    The project site is located in the middle of San Francisco Bay on 
the western shoreline of Treasure Island just where the island ends and 
connects by a narrow road to the smaller Yerba Buena Island to the 
south (Figure 1). The San Francisco-Oakland Bay Bridge runs through a 
tunnel on Yerba Buena Island. There is a known harbor seal haulout 
location on Yerba Buena Island on the southern shoreline just east of 
the bridge. The project location is separated from the haulout by 
approximately 0.85 miles (1.4 km) of shoreline but there is no direct 
line of sight with the project. After November 30, when more seals may 
be present at the Yerba Buena haulout, only concrete piles or vibratory 
driving/extraction of steel piles will occur.
[GRAPHIC] [TIFF OMITTED] TN09JN20.003


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Detailed Description of Specific Activity

    The proposed project includes an approximately 5,175-square-foot 
float with a temporary water taxi landing supported by 36-inch-diameter 
steel piles and an approximately 1,170-square-foot gangway; an 
approximately 2,400-square foot section of a pier with a canopy 
supported by 48-inch diameter steel piles (driven using a combination 
of vibratory and impact); a fireboat access platform with supporting 
utilities consisting of a 2,500 square foot pier supported by 48-inch 
diameter steel piles and 36-inch diameter steel piles; and a 
breakwater, approximately 820 feet long supported by 24-inch diameter 
concrete batter piles and 14-inch by 48-inch sheet piles north of the 
terminal with an approximately 2,400-square-foot rock revetment 
connecting the breakwater to the shoreline (see application Figure 2). 
The temporary water taxi landing is to allow smaller watercraft ferry 
dock landing access when the ferry service is limited to one ferryboat. 
The project will also remove an approximately 11,684-square-foot old 
pier, including 12-inch diameter timber piles and bents and an 
approximately 258-square-foot gangway. These timber piles will be 
pulled or vibrated out entirely unless broken; broken piles will be cut 
3 feet below the mudline. A number of temporary 14-inch by 89-foot 
steel template h-piles will be driven using a vibratory hammer, as well 
as temporary 14-inch by 89-foot steel template batter piles (h-piles) 
will be driven using a vibratory hammer. Temporary 36-inch diameter 
steel mooring piles will be driven using a vibratory hammer, and 14-
inch by 89-foot mooring batter piles (steel h-piles) will be driven 
using a vibratory hammer. Temporary piles will also be removed by 
vibratory hammer. A total of 784 piles will be driven or removed; see 
Table 1 for detailed summary of pile activities. The piles will be 
installed to an estimated depth of embedment of 50 to 90 feet below the 
bay bottom, to be confirmed by geotechnical investigation.
    The pile driving equipment will be deployed and operated from 
barges, on water. Materials will be delivered on barges. Between 3 and 
15 piles will be placed/removed daily (with the larger piles taking 
more time to install, and therefore fewer will be installed per day). 
Temporary piles will be placed to assist in the installation of the 
supporting piles for each structure. The temporary piles will be 
removed when the associated permanent piles are installed. Pile 
installation will be completed with the use of two to three cranes and 
hammers, at times operating simultaneously.
    Work is proposed to occur on the following schedule:
     Ferry pier pile and North breakwater template H pile 
driving will occur on 27 days in June 2020.
     North breakwater sheet pile and template H pile driving 
will occur on 162 days from July 2020 to January 15, 2021.
     Old pier timber piles will be removed during the north 
breakwater pile driving from July 2020 to December 2020.

                                   Table 1--Summary of Pile Driving Activities
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                                                                                         Piles
                                                                     -------------------------------------------
                Activity                           Location               Number
                                                                         (maximum)               Type
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Install Piles for Ferry Pier (impact and/ Ferry Pier................               4  36-inch steel pipe
 or vibratory).                                                                        (mooring piles)/
                                                                                       vibratory.
                                          Ferry Pier................               2  48-inch steel pipe
                                                                                       vibratory & impact.
                                          Ferry Pier................               2  36-inch steel pipe (fender
                                                                                       piles)/vibratory.
Install Temporary Steel Template Piles    Ferry Pier................              20  14-inch x 89-foot steel H-
 (Vibratory).                                                                          piles.
Remove Temporary Steel Template Piles     Ferry Pier................              20  14-inch x 89-foot steel H-
 (Vibratory).                                                                          piles.
Install Octagonal for North Breakwater    North Breakwater..........              52  24-inch octagonal
 (impact).                                                                             concrete.
Install Sheetpiles for North Breakwater   North Breakwater..........             120  14 x 48-inch concrete
 (impact).                                                                             sheetpiles.
Install Temporary Steel Template Piles    North Breakwater..........             108  14-inch x 89-foot steel H-
 (Vibratory).                                                                          piles.
Remove Temporary Steel Template Piles     North Breakwater..........             108  14-inch x 89-foot steel H-
 (Vibratory).                                                                          piles.
Install Temporary Steel Template Batter   North Breakwater..........              46  14-inch x 89-foot steel H-
 Piles (Vibratory).                                                                    piles.
Remove Temporary Steel Template Batter    North Breakwater..........              46  14-inch x 89-foot steel H-
 Piles (Vibratory).                                                                    piles.
Install Temporary Mooring Piles           Mooring...................               2  36-inch steel pipe.
 (Vibratory).
Remove Temporary Mooring Piles            Mooring...................               2  36-inch steel pipe.
 (Vibratory).
Install Temporary Mooring Batter Piles    Mooring...................               4  14-inch x 89-foot steel H-
 (Vibratory).                                                                          piles.
Remove Temporary Mooring Batter Piles     Mooring...................               4  14-inch x 89-foot steel H-
 (Vibratory).                                                                          piles.
Install Crew Access Piles (Vibratory)...  Mooring...................               2  14-inch x 89-foot steel H-
                                                                                       piles.
Remove Crew Access Piles (Vibratory)....  Mooring...................               2  14-inch x 89-foot steel H-
                                                                                       piles.
Install Fireboat Access Pier (Vibratory   North Breakwater..........               3  48-inch steel pipe.
 & Impact).
Install Fireboat Access Pier (Vibratory)  North Breakwater..........               2  36-inch steel pipe.
Install Temporary Fireboat Steel          North Breakwater..........              16  14-inch x 89-foot steel H-
 Template Piles (Vibratory).                                                           piles.
Remove Temporary Fireboat Steel Template  North Breakwater..........              16  14-inch x 89-foot steel H-
 Piles (Vibratory).                                                                    piles.
Remove Existing Pier (vibratory or crane  Pier......................             198  12-inch timber.
 cable).
                                         -----------------------------------------------------------------------
    Total...............................  ..........................             784  N/A.
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    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 with expected potential for occurrence in 
the project area near Treasure Island and summarizes information 
related to the population or stock, including regulatory status under 
the MMPA and ESA and potential biological removal (PBR), where known. 
For taxonomy, we

[[Page 35274]]

follow Committee on Taxonomy (2019). 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 SARs and draft SARs (e.g., Caretta et al. 2019).

                    Table 2--Species That Spatially Co-Occur With the Activity to the Degree That Take Is Reasonably Likely To Occur
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                                                                                                             Stock abundance (CV,
                                                                                         ESA/MMPA status;      Nmin, most recent               Annual M/
             Common name                  Scientific name               Stock            Strategic (Y/N) 1    abundance survey) 2      PBR        SI 3
 
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                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Eschrichtiidae:
    Gray Whale......................  Eschrichtius robustus..  Eastern North Pacific..  -, -, N             26,960 (0.05, 25,849,         801        138
                                                                                                             2016).
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                            Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Delphinidae:
    Bottlenose Dolphin..............  Tursiops truncatus.....  California Coastal.....  -, -, N             453 (0.06, 346, 2011).        2.7       >2.0
Family Phocoenidae (porpoises):
    Harbor porpoise.................  Phocoena phocoena......  San Francisco/Russian    -, -, N             9,886 (0.51, 2019)....         66          0
                                                                River.
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                                                         Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California Sea Lion.............  Zalophus californianus.  United States..........  -, -, N             257,606 (N/A, 233,515,     14,011       >321
                                                                                                             2014).
    Northern fur seal...............  Callorhinus ursinus....  California.............  -, D, N             14,050 (N/A, 7,524,           451        1.8
                                                                                                             2013).
                                                               Eastern North Pacific..  -, D, N             620,660 (0.2, 525,333,     11,295        399
                                                                                                             2016).
Family Phocidae (earless seals):
    Northern elephant seal..........  Mirounga angustirostris  California Breeding....  -, -, N             179,000 (N/A, 81,368,       4,882        8.8
                                                                                                             2010).
    Harbor seal.....................  Phoca vitulina.........  California.............  -, -, N             30,968 (N/A, 27,348,        1,641          4
                                                                                                             2012).
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1 Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
2 NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance.
3 These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
  with estimated mortality due to commercial fisheries is presented in some cases.

    Harbor seal, California sea lion, bottlenose dolphin and Harbor 
porpoise spatially co-occur with the activity to the degree that take 
is reasonably likely to occur, and we have proposed authorizing take of 
these species. For gray whale, northern fur seal and northern elephant 
seal, occurrence is such that take is possible, and we have proposed 
authorizing take of these species also. All species that could 
potentially occur in the proposed survey areas are included in San 
Francisco's IHA application (see application, Table 2). Humpback whales 
could potentially occur in the area. However the spatial and temporal 
occurrence of this species is very rare, the species is readily 
observed, and the applicant would shut down pile driving if humpback 
whales enter the project area. Thus take is not expected to occur, and 
they are not discussed further.

Bottlenose Dolphin

    The California coastal stock of common bottlenose dolphin is found 
within 0.6 mi (1 km) of shore (Defran and Weller, 1999) and occurs from 
northern Baja California, Mexico to Bodega Bay, CA. Their range has 
extended north over the last several decades with El Ni[ntilde]o events 
and increased ocean temperatures (Hansen and Defran, 1990). Genetic 
studies have shown that no mixing occurs between the California coastal 
stock and the offshore common bottlenose dolphin stock (Lowther-
Thieleking et al., 2015). Bottlenose dolphins are opportunistic 
foragers: Time of day, tidal state, and oceanographic habitat influence 
where they pursue prey (Hanson and Defran, 1993). Dive durations up to 
15 minutes have been recorded for trained Navy bottlenose dolphins, 
(Ridgway et al., 1969), but typical dives are shallower and of a much 
shorter duration (approximately 30; et al., 1999, Mate et al., 1995).
    Bottlenose dolphins began entering San Francisco Bay in 2010 
(Szczepaniak, 2013). They primarily occur in the western Central and 
South Bay, from the Golden Gate Bridge to Oyster Point and Redwood 
City. However, one individual has been regularly seen in San Francisco 
Bay since 2016 near the former Alameda Air Station (Perlman, 2017; W. 
Keener, pers. comm. 2017), and five animals were regularly seen in the 
summer and fall of 2018 in the same location (W. Keener, pers. comm. 
2019).

[[Page 35275]]

Harbor Porpoise

    Harbor porpoise occur along the U.S. west coast from southern 
California to the Bering Sea (Carretta et al., 2019). They rarely occur 
in waters warmer than 62.6 degrees Fahrenheit (17 degrees Celsius; 
Read, 1990). The San Francisco-Russian River stock is found from 
Pescadero, 18 mi (30 km) south of the San Francisco Bay, to 99 mi (160 
km) north of the bay at Point Arena (Carretta et al., 2014). In most 
areas, harbor porpoise occur in small groups of just a few individuals.
    Harbor porpoise sightings in the San Francisco Bay declined in the 
1930's and were functionally extirpated shortly after. Harbor porpoise 
occur frequently outside San Francisco Bay and re-entered the bay 
beginning in 2008 (Stern et al., 2017). They now commonly occur year-
round within San Francisco Bay, primarily on the west and northwest 
side of the Central Bay near the Golden Gate Bridge, near Marin County, 
and near the city of San Francisco (Duffy 2015, Keener et al., 2012; 
Stern et al., 2017). In the summer of 2017 and 2018, mom-calf pairs and 
small groups (one to four individuals) were seen to the north and west 
of Treasure Island, and just south of Yerba Buena Island (Caltrans 
2018a, 2019; M. Schulze, pers. comm. 2019).
    Harbor porpoise must forage nearly continuously to meet their high 
metabolic needs (Wisniewska et al., 2016). They consume up to 550 small 
fish (1.2-3.9 in [3-10 cm]; e.g. anchovies) per hour at a nearly 90 
percent capture success rate (Wisniewska et al., 2016).

California Sea Lion

    California sea lions occur from Vancouver Island, British Columbia, 
to the southern tip of Baja California. Sea lions breed on the offshore 
islands of southern and central California from May through July (Heath 
and Perrin, 2008). During the non-breeding season, adult and subadult 
males and 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 (Heath 
and Perrin 2008, Lowry and Forney 2005). Females and some juveniles 
tend to remain closer to rookeries (Antonelis et al., 1990; Melin et 
al., 2008).
    California sea lions have occupied docks near Pier 39 in San 
Francisco, a few miles from the project area, since 1987. The highest 
number of sea lions recorded at Pier 39 was 1,701 individuals in 
November 2009. Occurrence of sea lions here is typically lowest in June 
(during pupping and breeding seasons) and highest in August. 
Approximately 85 percent of the animals that haul out at this site are 
males, and no pupping has been observed here or at any other site in 
San Francisco Bay. Pier 39 is the only regularly used haulout site in 
the project vicinity, but sea lions occasionally haul out on human-made 
structures such as bridge piers, jetties, or navigation buoys (Riedman 
1990).
    Pupping occurs primarily on the California Channel Islands from 
late May until the end of June (Peterson and Bartholomew 1967). Weaning 
and mating occur in late spring and summer during the peak upwelling 
period (Bograd et al., 2009). After the mating season, adult males 
migrate northward to feeding areas as far away as the Gulf of Alaska 
(Lowry et al., 1992), and they remain away until spring (March-May), 
when they migrate back to the breeding colonies. Adult females 
generally remain south of Monterey Bay, California throughout the year, 
feeding in coastal waters in the summer and offshore waters in the 
winter, alternating between foraging and nursing their pups on shore 
until the next pupping/breeding season (Melin and DeLong, 2000; Melin 
et al., 2008).

Northern Fur Seal

    Two northern fur seal stocks may occur near San Francisco Bay: The 
California and Eastern North Pacific stocks. The California stock 
breeds and pups on the offshore islands of California, and forages off 
the California coast. The Eastern Pacific stock breeds and pups on 
islands in the North Pacific Ocean and Bering Sea, including the 
Aleutian Islands, Pribilof Islands, and Bogoslof Island, but females 
and juveniles move south to California waters to forage in the fall and 
winter months (Gelatt and Gentry, 2018). Breeding and pupping occur 
from mid- to late-May into July. Pups are weaned in September and move 
south to feed offshore California (Gentry, 1998).
    Both the California and Eastern North Pacific stocks forage in the 
offshore waters of California, but usually only sick or emaciated 
juvenile fur seals seasonally enter the bay. The Marine Mammal Center 
(TMMC) occasionally picks up stranded fur seals around Yerba Buena and 
Treasure Islands (NMFS, 2019b).

Northern Elephant Seal

    Northern elephant seals are common on California coastal mainland 
and island sites, where the species pups, breeds, rests, and molts. The 
largest rookeries are on San Nicolas and San Miguel islands in the 
northern Channel Islands. Near San Francisco Bay, elephant seals breed, 
molt, and haul out at A[ntilde]o Nuevo Island, the Farallon Islands, 
and Point Reyes National Seashore.
    Northern elephant seals haul out to give birth and breed from 
December through March. Pups remain onshore or in adjacent shallow 
water through May. Both sexes make two foraging migrations each year: 
One after breeding and the second after molting (Stewart, 1989; Stewart 
and DeLong, 1995). Adult females migrate to the central North Pacific 
to forage, and males migrate to the Gulf of Alaska to forage (Robinson 
et al., 2012). Pup mortality is high when they make the first trip to 
sea in May, and this period correlates with the time of most 
strandings. Young-of-the-year pups return in the late summer and fall 
to haul out at breeding rookeries and small haulout sites, but 
occasionally may make brief stops in San Francisco Bay.

Harbor Seal

    Harbor seals are found from Baja California to the eastern Aleutian 
Islands of Alaska (Harvey and Goley, 2011). In California there are 
approximately 500 haulout sites along the mainland and on offshore 
islands, including intertidal sandbars, rocky shores, and beaches 
(Hanan, 1996; Lowry et al., 2008).
    Harbor seals are the most common marine mammal species observed in 
the San Francisco Bay. Within the bay they primarily haul out on 
exposed rocky ledges and on sloughs in the southern San Francisco Bay. 
Harbor seals are central-place foragers (Orians and Pearson, 1979) and 
tend to exhibit strong site fidelity within season and across years, 
generally forage close to haulout sites, and repeatedly visit specific 
foraging areas (Grigg et al., 2012; Suryan and Harvey, 1998; Thompson 
et al., 1998). Harbor seals in San Francisco Bay forage mainly within 7 
mi (10 km) of their primary haulout site (Grigg et al., 2012), and 
often within just 1-3 mi (1-5 km; Torok, 1994). Depth, bottom relief, 
and prey abundance also influence foraging location (Grigg et al., 
2012).
    Harbor seals molt from May through June. Peak numbers of harbor 
seals haul out in central California during late May to early June, 
which coincides with the peak molt. During both pupping and molting 
seasons, the number of seals and the length of time hauled out per day 
increase, from an average of 7 hours per day to 10-12 hours (Harvey and 
Goley, 2011; Huber et al., 2001; Stewart and Yochem, 1994).

[[Page 35276]]

    Harbor seals tend to forage at night and haul out during the day 
with a peak in the afternoon between 1 p.m. and 4 p.m. (Grigg et al., 
2012; London et al., 2001; Stewart and Yochem, 1994; Yochem et al., 
1987). Tide levels affect the maximum number of seals hauled out, with 
the largest number of seals hauled out at low tide, but time of day and 
season have the greatest influence on haul out behavior (Manugian et 
al., 2017; Patterson and Acevedo-Guti[eacute]rrez, 2008; Stewart and 
Yochem, 1994).
    The closest haulout to the project area is on Yerba Buena Island as 
noted above. This haulout site has a daily range of zero to 109 harbor 
seals during fall months, with the highest numbers hauled out during 
afternoon low tides (Caltrans, 2004). The Golden Gate National 
Recreation Area contains a number of haul out areas in San Francisco 
Bay including Alcatraz Island and Point Bonita at the entrance to the 
bay (NPS, 2016).
    Large concentrations of spawning Pacific herring (Clupea pallasii) 
and migrating salmonids likely attract seals into San Francisco Bay 
during the winter months (Greig and Allen, 2015). Harbor seals forage 
for Pacific herring in eelgrass beds in the winter (Schaeffer et al., 
2007).
    Pupping occurs from March through May in central California (Codde 
and Allen, 2018). Pups are weaned in four weeks, most by mid-June 
(Codde and Allen, 2018). Harbor seals molt from June through July 
(Codde and Allen, 2018) and breed between late March and June (Greig 
and Allen, 2015). The closest recognized harbor seal pupping site to 
the project is at Castro Rocks, approximately 12 miles (20 km) from the 
project area.

Gray Whale

    In the fall, gray whales migrate from their summer feeding grounds, 
heading south along the coast of North America to spend the winter in 
their breeding and calving areas off the coast of Baja California, 
Mexico. From mid-February to May, the Eastern North Pacific stock of 
gray whales can be seen migrating northward with newborn calves along 
the west coast of the U.S. During the migration, gray whales will 
occasionally enter rivers and bays (such as San Francisco Bay) along 
the coast but not in high numbers. In recent years there have been an 
increased number of gray whales in the San Francisco Bay (W. Keener, 
pers. comm. 2019).

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.

           Table 3--Marine Mammal Hearing Groups (NMFS, 2018)
------------------------------------------------------------------------
                                                   Generalized hearing
                 Hearing group                           range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen whales)..  7 Hz to 35 kHz.
Mid-frequency (MF) cetaceans (dolphins,         150 Hz to 160 kHz.
 toothed whales, beaked whales, bottlenose
 whales).
High-frequency (HF) cetaceans (true porpoises,  275 Hz to 160 kHz.
 Kogia, river dolphins, cephalorhynchid,
 Lagenorhynchus cruciger & L. australis).
Phocid pinnipeds (PW) (underwater) (true        50 Hz to 86 kHz.
 seals).
Otariid pinnipeds (OW) (underwater) (sea lions  60 Hz to 39 kHz.
 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. 
Harbor seals are in the phocid group and Dall's and harbor porpoises 
are classified as high-frequency cetaceans.

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.
    Acoustic effects on marine mammals during the specified activity 
can occur from vibratory and impact pile driving. The effects of 
underwater noise from Pacific Shops' proposed activities have the 
potential to result in Level A or Level B harassment of marine mammals 
in the action area.

Description of Sound Sources

    The marine soundscape is comprised of both ambient and 
anthropogenic sounds. Ambient sound is defined as the all-encompassing 
sound in a given

[[Page 35277]]

place and is usually a composite of sound from many sources both near 
and far (ANSI 1994, 1995). 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 (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on 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 
from day to day (Richardson et al., 1995). The result is that, 
depending on 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 may affect marine 
mammals.
    In-water construction activities associated with the project would 
include impact pile driving, vibratory pile driving, and vibratory pile 
removal. The sounds produced by these activities fall into one of two 
general sound types: Impulsive and non-impulsive. 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). Non-impulsive sounds (e.g., 
machinery operations such as drilling or dredging, vibratory pile 
driving, 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 raid rise/decay time that 
impulsive sounds do (ANSI 1995; NIOSH 1998; NMFS 2018). The distinction 
between these two sound types 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).
    Two types of pile hammers would be used on this project: Impact and 
vibratory. 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 piles by vibrating them and allowing 
the weight of the hammer to push them into the sediment. 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 impact pile 
driving of the same-sized 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 San Francisco'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 the equipment and personnel; however, any impacts 
to marine mammals are expected to primarily be acoustic in nature. 
Acoustic stressors include effects of heavy equipment operation during 
pile installation and removal.

Acoustic Impacts

    The introduction of anthropogenic noise into the aquatic 
environment from pile driving and removal is the primary means by which 
marine mammals may be harassed from San Francisco's specified activity. 
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). Generally, exposure to 
pile driving and drilling noise has the potential to result in auditory 
threshold shifts 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 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 driving and drilling 
noise on marine mammals are dependent on several factors, including, 
but not limited to, sound type (e.g., impulsive vs. non-impulsive), 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 physical auditory effects (threshold shifts) followed by 
behavioral effects and potential impacts on habitat.
    NMFS defines a noise-induced threshold shift (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 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 the 
TS, time to recovery (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 animal uses sound within the 
frequency band of the signal; e.g., Kastelein 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; Ahroon et al., 1996; Henderson and 
Hu, 2008). PTS levels for marine mammals are estimates, 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)--A temporary, reversible increase 
in the threshold of audibility at a specified

[[Page 35278]]

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 (2016), 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 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). The potential for TTS from impact pile driving 
exists. After exposure to playbacks of impact pile driving sounds (rate 
2760 strikes/hour) in captivity, mean TTS increased from 0 dB after 15 
minute exposure to 5 dB after 360 minute exposure; recovery occurred 
within 60 minutes (Kastelein et al., 2016). 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).
    Installing piles requires a combination of impact pile driving and 
vibratory pile driving. For this project, these activities could occur 
at the same time because of the use of multiple hammers. There would 
likely be pauses in activities producing the sound during each day. 
Given these pauses and that many marine mammals are likely moving 
through the action area and not remaining for extended periods of time, 
the potential for TS declines.
    Behavioral Harassment--Exposure to noise from pile driving and 
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., Lusseau and Bejder, 2007; Weilgart, 2007; NRC, 2005).
    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; 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 the source). 
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. Please see Appendices B and 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.
    In 2016, the Alaska Department of Transportation and Public 
Facilities (ADOT&PF) documented observations of marine mammals during 
construction activities (i.e., pile driving) at the Kodiak Ferry Dock 
(see 80 FR 60636, October 7, 2015). In the marine mammal monitoring 
report for that project (ABR 2016), 1,281 Steller sea lions were 
observed within the Level B disturbance zone during pile driving or 
drilling (i.e., documented as Level B harassment take). Of these, 19 
individuals

[[Page 35279]]

demonstrated an alert behavior, 7 were fleeing, and 19 swam away from 
the project site. All other animals (98 percent) were engaged in 
activities such as milling, foraging, or fighting and did not change 
their behavior. In addition, two sea lions approached within 20 meters 
of active vibratory pile driving activities. Three harbor seals were 
observed within the disturbance zone during pile driving activities; 
none of them displayed disturbance behaviors. Fifteen killer whales and 
three harbor porpoise were also observed within the Level B harassment 
zone during pile driving. The killer whales were travelling or milling 
while all harbor porpoises were travelling. No signs of disturbance 
were noted for either of these species. Given the similarities in 
activities and habitat and the fact the some of same species are 
involved, we expect similar behavioral responses of marine mammals to 
San Francisco's specified activity. That is, disturbance, if any, is 
likely to be temporary and localized (e.g., small area movements).
    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., 2002b) and, more rarely, studied in wild populations (e.g., 
Romano et al., 2002a). 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. The 
San Francisco area contains active commercial shipping, cruise ship and 
ferry operations, as well as numerous recreational and other commercial 
vessels; therefore, background sound levels in the area are already 
elevated.
    Airborne Acoustic Effects--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal that have the potential to cause behavioral harassment, 
depending on their distance from pile driving activities. Cetaceans are 
not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.
    Airborne noise would 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 their heads above 
water. Most likely, airborne sound would cause behavioral responses 
similar to those discussed above in relation to underwater sound. For 
instance, anthropogenic sound could cause hauled-out pinnipeds to 
exhibit changes in their normal behavior, such as reduction in 
vocalizations, or cause them to temporarily abandon the area and move 
further from the source. However, these animals would previously have 
been `taken' because of exposure to underwater sound above the 
behavioral harassment thresholds, which are in all cases larger than 
those associated with airborne sound. Thus, the behavioral harassment 
of these animals is already accounted for in these estimates of 
potential take. In the case of the Yerba Buena haulout nearest to this 
project, airborne sounds would also be blocked by the island and the 
haulout is too far from the project site. Therefore, we do not believe 
that authorization of incidental take resulting from airborne sound for

[[Page 35280]]

pinnipeds is warranted, and airborne sound is not discussed further 
here.

Marine Mammal Habitat Effects

    San Francisco's construction activities could have localized, 
temporary impacts on marine mammal habitat and their prey by increasing 
in-water sound pressure levels and slightly decreasing water quality. 
Increased noise levels may affect acoustic habitat (see masking 
discussion above) and adversely affect marine mammal prey in the 
vicinity of the project area (see discussion below). During impact and 
vibratory pile driving, elevated levels of underwater noise would 
ensonify San Francisco Bay where both fishes and mammals occur and 
could affect foraging success. Additionally, marine mammals may avoid 
the area during construction, however, displacement due to noise is 
expected to be temporary and is not expected to result in long-term 
effects to the individuals or populations. Construction activities are 
of short duration and would likely have temporary impacts on marine 
mammal habitat through increases in underwater and airborne sound.
    A temporary and localized increase in turbidity near the seafloor 
would occur in the immediate area surrounding the area where piles are 
installed or removed. In general, turbidity associated with pile 
installation is localized to about a 25-foot (7.6-meter) radius around 
the pile (Everitt et al. 1980). Cetaceans are not expected to be close 
enough to the pile driving areas to experience effects of turbidity, 
and any pinnipeds could avoid localized areas of turbidity. Local 
strong currents are anticipated to disburse any additional suspended 
sediments produced by project activities at moderate to rapid rates 
depending on tidal stage. Therefore, we expect the impact from 
increased turbidity levels to be discountable to marine mammals and do 
not discuss it further.

In-Water Construction Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat (e.g., most of the impacted area is 
west of Treasure Island) of San Francisco Bay and does not include any 
Biologically Important Areas or other habitat of known importance. The 
area is highly influenced by anthropogenic activities. The total 
seafloor area affected by pile installation and removal is a very small 
area compared to the vast foraging area available to marine mammals in 
the San Francisco Bay. At best, the impact area provides marginal 
foraging habitat for marine mammals and fish, while the new pilings 
installed would provide substrate for invertebrate prey to settle on. 
Furthermore, pile driving and removal at the project site would not 
obstruct movements or migration of marine mammals.
    Avoidance by potential prey (i.e., fish) of the immediate area due 
to the temporary loss of this foraging habitat is also possible. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity.
    In-water Construction Effects on Potential Prey--Sound may affect 
marine mammals through impacts on the abundance, behavior, or 
distribution of prey species (e.g., crustaceans, cephalopods, fish, 
zooplankton). 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 and Mann., 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. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. 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. Additional studies 
have documented effects of pile driving on fish, although several are 
based on studies in support of large, multiyear bridge construction 
projects (e.g., Scholik and Yan, 2001, 2002; Popper and Hastings, 
2009). Several studies have demonstrated that impulse sounds might 
affect the distribution and behavior of some fishes, potentially 
impacting foraging opportunities or increasing energetic costs (e.g., 
Fewtrell and McCauley, 2012; Pearson et al., 1992; Skalski et al., 
1992; Santulli et al., 1999; Paxton et al., 2017). However, some 
studies have shown no or slight reaction to impulse sounds (e.g., Pena 
et al., 2013; Wardle et al., 2001; 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 driving activities at the 
project area would be temporary behavioral avoidance of the area. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated.
    Construction activities, in the form of increased turbidity, have 
the potential to adversely affect forage fish and juvenile salmonid out 
migratory routes in the project area. Both herring and salmon form a 
significant prey base for many marine mammal species that occur in the 
project area. Increased turbidity is expected to occur in the immediate 
vicinity (on the order of 10 feet (3 m) or less) of construction 
activities. However, suspended sediments and particulates are expected 
to dissipate quickly within a single tidal cycle. Given the limited 
area affected and high tidal dilution rates any effects on forage fish 
and salmon are expected to be minor or negligible. Finally, exposure to 
turbid waters from construction activities is not expected to be 
different from the current exposure; fish and marine mammals in San 
Francisco Bay are routinely exposed to substantial levels of suspended

[[Page 35281]]

sediment from natural and anthropogenic sources.
    In summary, given the short daily duration of sound associated with 
individual pile driving events and the relatively small areas being 
affected, pile driving activities associated with the proposed action 
are not likely to have a permanent, adverse effect on any fish habitat, 
or populations of fish species. Any behavioral avoidance by fish of the 
disturbed area would still leave significantly large areas of fish and 
marine mammal foraging habitat in the nearby vicinity. Thus, we 
conclude that impacts of the specified activity are not likely to have 
more than short-term adverse effects on any prey habitat or populations 
of prey species. Further, any impacts to marine mammal habitat are not 
expected to result in significant or long-term consequences for 
individual marine mammals, or to contribute to adverse impacts on their 
populations.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, 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 use 
of the acoustic source (i.e., vibratory or impact pile driving) has the 
potential to result in disruption of behavioral patterns for individual 
marine mammals. There is also some potential for auditory injury (Level 
A harassment) to result for pinnipeds and harbor porpoise because 
predicted auditory injury zones are larger. 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) 
and 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). Due to the lack of marine 
mammal density for some species, NMFS relied on local occurrence data 
and group size to estimate take. Below, we describe the factors 
considered here in more detail and present the proposed take estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed 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).
    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) and above 160 dB 
re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., impact pile 
driving) or intermittent (e.g., scientific sonar) sources.
    San Francisco's proposed activity includes the use of continuous 
(vibratory pile-driving) and impulsive (impact pile-driving) sources, 
and therefore the 120 and 160 dB re 1 [mu]Pa (rms) thresholds are 
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). PSSA's activity includes the use of 
impulsive (impact pile-driving) and non-impulsive (vibratory pile 
driving/removal) sources.
    These thresholds are provided in Table 4. 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 acoustic thresholds \*\ (received level)
             Hearing group              ------------------------------------------------------------------------
                                                  Impulsive                         Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans...........  Cell 1: Lpk,flat: 219 dB;   Cell 2: LE,LF,24h: 199 dB.
                                          LE, LF,24h: 183 dB.
Mid-Frequency (MF) Cetaceans...........  Cell 3: Lpk,flat: 230 dB;   Cell 4: LE,MF,24h: 198 dB.
                                          LE,MF,24h: 185 dB.
High-Frequency (HF) Cetaceans..........  Cell 5: Lpk,flat: 202 dB;   Cell 6: LE,HF,24h: 173 dB.
                                          LE,HF,24h: 155 dB.
Phocid Pinnipeds (PW)..................  Cell 7: Lpk,flat: 218 dB;   Cell 8: LE,PW,24h: 201 dB.
(Underwater)...........................   LE,PW,24h: 185 dB.

[[Page 35282]]

 
Otariid Pinnipeds (OW).................  Cell 9: Lpk,flat: 232 dB;   Cell 10: LE,OW,24h: 219 dB.
(Underwater)...........................   LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for
  calculating PTS onset. If a non-impulsive sound has the potential of exceeding the peak sound pressure level
  thresholds associated with impulsive sounds, these thresholds should also be considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [micro]Pa, and cumulative sound exposure level (LE)
  has a reference value of 1[micro]Pa\2\s. In this Table, thresholds are abbreviated to reflect American
  National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined by ANSI as
  incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript
  ``flat'' is being included to indicate peak sound pressure should be flat weighted or unweighted within the
  generalized hearing range. The subscript associated with cumulative sound exposure level thresholds indicates
  the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could
  be exceeded in a multitude of ways (i.e., varying exposure levels and durations, duty cycle). When possible,
  it is valuable for action proponents to indicate the conditions under which these acoustic thresholds will be
  exceeded.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficient.
    The sound field in the project area is the existing background 
noise plus additional construction noise from the proposed project. 
Marine mammals are expected to be affected via sound generated by the 
primary components of the project (i.e., impact pile driving, vibratory 
pile driving, vibratory pile removal).
    Vibratory hammers produce constant sound when operating, and 
produce vibrations that liquefy the sediment surrounding the pile, 
allowing it to penetrate to the required seating depth. An impact 
hammer would then generally be used to place the pile at its intended 
depth through rock or harder substrates. The actual durations of each 
installation method vary depending on the type and size of the pile. An 
impact hammer is a steel device that works like a piston, producing a 
series of independent strikes to drive the pile. Impact hammering 
typically generates the loudest noise associated with pile 
installation.
    In order to calculate distances to the Level A harassment and Level 
B harassment sound thresholds for piles of various sizes being used in 
this project, NMFS used acoustic monitoring data from other locations 
to develop source levels or the various pile types, sizes and methods 
(see Table 5).

                                                          Table 5--Project Sound Source Levels
--------------------------------------------------------------------------------------------------------------------------------------------------------
                         Pile driving activity                             Estimated sound source level at 10 meters
-----------------------------------------------------------------------               without attenuation
                                                                       ------------------------------------------------            Data source
               Hammer type                          Pile type               dB RMS          dB SEL          dB peak
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact...................................  36-inch steel pipe.........             193             183             210  Compendium pg. 131 (Buehler et
                                                                                                                         al. 2015) Humboldt
                                           48-inch steel pipe.........             195             185           * 210  Compendium pg. 132 (Buehler et
                                                                                                                         al. 2015) Russian River
                                           24-inch octagonal concrete.             170             164             189  Measurements at Pile 3B, 9/10/
                                                                                                                         2019 at Alameda Seaplane Lagoon
                                                                                                                         Project (Illingworth and
                                                                                                                         Rodkin, Inc., 2019a)
                                           14-inch x 48-inch concrete              156             146             167  Treasure Island (Illingworth and
                                            sheetpile (measured at                                                       Rodkin, Inc., 2019b)
                                            33m).
Vibratory................................  36-inch steel pipe.........             170  ..............  ..............  Compendium pg. 129 (Buehler et
                                                                                                                         al. 2015)
                                           48'' steel pipe............          ** 170  ..............  ..............  Pile-Driving Noise Measurements
                                                                                                                         at Atlantic Fleet Naval
                                                                                                                         Installations (Illingworth and
                                                                                                                         Rodkin, Inc., 2017)
                                           14-inch x 89-foot steel H-              150  ..............  ..............  Compendium pg. 129 (Buehler et
                                            piles.                                                                       al. 2015)
Vibratory Removal........................  12-inch timber piles                    150  ..............  ..............  Port Townsend Dolphin Timber
                                            (measured at 15.8m).                                                         Pile Removal (WSDOT 2011) ***
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: It is assumed that noise levels during pile installation and removal are similar. Use of an impact hammer will be limited to 5-10 minutes per
  pile, if necessary. SEL = single strike sound exposure level; dB peak = peak sound level; rms = root mean square.
* The peak source level from the Compendium is 205 dB; because the peak source for 36-inch piles was 210 dB we conservatively increased this source
  level to 210 dB to be no less than the 36-inch piles.
** No sound source level information for vibratory driving for 48-inch steel pipes is available in the Compendium. Sound source levels of 48-inch piles
  for the Atlantic Fleet Naval Installations (162 dB) were lower than those listed for 36-inch piles in the Compendium (170 dB rms). Sound source levels
  for 48-inch piles are expected to be at least as high as those measured for 36-inch piles. Sound source levels from the Compendium for 72inch piles
  were also 170 dB rms. As such, 170 dB rms was used for isopleth calculations for 48-inch piles.
*** NMFS typically uses Greenbusch Group (2018) data for source levels for timber pile removal, but the applicant chose the more conservative WSDOT
  (2011). The source level from Greenbush Group (2018) is 152 dB at 10m, the equivalent source level for WSDOT (2011) at 10m is 153 dB.


[[Page 35283]]

    During pile driving installation activities, there may be times 
when multiple hammers are used simultaneously. For impact hammering, it 
is unlikely that the two hammers would strike at the same exact 
instant, and therefore, the sound source levels will not be adjusted 
regardless of the distance between the hammers. For this reason, 
multiple impact hammering is not discussed further. For simultaneous 
vibratory hammering, the likelihood of such an occurrence is 
anticipated to be infrequent and would be for short durations on that 
day. In-water pile installation is an intermittent activity, and it is 
common for installation to start and stop multiple times as each pile 
is adjusted and its progress is measured. When two continuous noise 
sources, such as vibratory hammers, have overlapping sound fields, 
there is potential for higher sound levels than for non-overlapping 
sources. When two or more vibratory hammers are used simultaneously, 
and the sound field of one source encompasses the sound field of 
another source, the sources are considered additive and combined using 
the following rules (see Table 6): For addition of two simultaneous 
vibratory hammers, the difference between the two sound source levels 
(SSLs) is calculated, and if that difference is between 0 and 1 dB, 3 
dB are added to the higher SSL; if difference is between 2 or 3 dB, 2 
dB are added to the highest SSL; if the difference is between 4 to 9 
dB, 1 dB is added to the highest SSL; and with differences of 10 or 
more dB, there is no addition.

                  Table 6--Rules for Combining Sound Levels Generated During Pile Installation
----------------------------------------------------------------------------------------------------------------
             Hammer types                 Difference in SSL          Level A zones            Level B zones
----------------------------------------------------------------------------------------------------------------
Vibratory, Impact....................  Any....................  Use impact zones.......  Use vibratory zone.
Impact, Impact.......................  Any....................  Use zones for each pile  Use zone for each pile
                                                                 size and number of       size.
                                                                 strikes.
Vibratory, Vibratory.................  0 or 1 dB..............  Add 3 dB to the higher   Add 3 dB to the higher
                                                                 source level.            source level.
                                       2 or 3 dB..............  Add 2 dB to the higher   Add 2 dB to the higher
                                                                 source level.            source level.
                                       4 to 9 dB..............  Add 1 dB to the higher   Add 1 dB to the higher
                                                                 source level.            source level.
                                       10 dB or more..........  Add 0 dB to the higher   Add 0 dB to the higher
                                                                 source level.            source level.
----------------------------------------------------------------------------------------------------------------
Source: Modified from USDOT 1995, WSDOT 2018, and NMFS 2018b.
Note: dB = decibels; SSL = sound source level.

    For simultaneous usage of three or more continuous sound sources, 
such as vibratory hammers, the three overlapping sources with the 
highest SSLs are identified. Of the three highest SSLs, the lower two 
are combined using the above rules, then the combination of the lower 
two is combined with the highest of the three. For example, with 
overlapping isopleths from 24-, 36-, and 42-inch diameter steel pipe 
piles with SSLs of 161, 167, and 168 dB rms respectively, the 24- and 
36-inch would be added together; given that 167 - 161 = 6 dB, then 1 dB 
is added to the highest of the two SSLs (167 dB), for a combined noise 
level of 168 dB. Next, the newly calculated 168 dB is added to the 42-
inch steel pile with SSL of 168 dB. Since 168 - 168 = 0 dB, 3 dB is 
added to the highest value, or 171 dB in total for the combination of 
24-, 36-, and 42-inch steel pipe piles (NMFS 2018b; WSDOT 2018). As 
described in Table 6, dB addition calculations were carried out for all 
possible combinations of vibratory installation.
    In consideration of the various pile types and sizes and the 
construction work plan for the different structures and components of 
the project, San Francisco developed a set of likely worst case 
scenarios for the activities that would be carried out over the course 
of individual days (Table 7). These scenarios encompass the worst 
possible combinations of simultaneous pile driving over the worst 
possible number of days it might take to complete those tasks. There 
are four basic scenarios plus the short-term addition of pile removal 
of the timber piles from the old pier. The course of the project is 
broken up into work windows for the first month of the project versus 
the remaining months. Within each of these temporal work windows there 
are some days with driving of larger and louder piles (called the 
maximum exposure days) and some days where driving will be of smaller 
piles (called average exposure days). The table shows what pile driving 
source is used to calculate the Level A and level B zones under each 
scenario.
    The applicant discusses how they will follow the California 
Environmental Quality Act requirement that a bubble curtain be used 
during operation of an impact hammer if sound pressures exceeded 160 dB 
at 500 meters from the source. Because San Francisco will not use a 
bubble curtain for all impact hammering of any pile size, we do not 
include a source level reduction for bubble curtain use or isopleth 
calculation for this project.

                       Table 7--Work Scenarios With Simultaneous Pile Driving Sources Used To Calculate Level A and Level B Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                    Piles                                              Loudest potential sound source
                                                                    driven                                                       combination
              Date                    Location       Total days   during 24       Drive type         Pile type     -------------------------------------
                                                                    hours                                                Level A            Level B
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Maximum Exposure Days
--------------------------------------------------------------------------------------------------------------------------------------------------------
June...........................  Ferry Pier.......            7            2  Impact...........  48-inch steel      Impact 48-inch     2 vibratory 14-
                                                                                                  pipe.              steel pipe.        inch x 89-foot
                                                                                                                                        steel H-pile.
                                 North Breakwater.  ...........            4  Vibratory........  14-inch x 89-foot                     .................
                                                                                                  steel H-piles.
July to January 15.............  North Breakwater.           50            4  Impact...........  24-inch octagonal  Impact 24-inch     2 vibratory 14-
                                                                                                  concrete or        octagonal          inch x 89-foot
                                                                                                  14x48-inch         concrete.          steel H-pile.
                                                                                                  concrete
                                                                                                  sheetpiles.
                                                                           4  Vibratory........  14-inch x 89-foot                     .................
                                                                                                  steel H-piles
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 35284]]

 
                                                                  Average Exposure Days
--------------------------------------------------------------------------------------------------------------------------------------------------------
June...........................  Ferry Pier.......           20            1  Vibratory........  48-inch steel      2 vibratory (48-   2 vibratory (48-
                                                                                                  pipe.              inch and 36-       inch and 36-
                                                                                                                     inch) steel        inch) steel
                                                                                                                     pipes.             pipes.
                                                                           1  Vibratory........  36-inch steel                         .................
                                                                                                  pipe (fender and/
                                                                                                  or mooring
                                                                                                  piles).
                                                                           2  Vibratory........  14-inch x 89-foot                     .................
                                                                                                  steel H-piles
July to January 15.............  North Breakwater.          112            1  Impact...........  14 x 48-inch       Impact 14 x 48-    2 vibratory 14-
                                                                                                  concrete           inch.              inch x 89-foot
                                                                                                  sheetpiles.                           steel H-pile.
                                                                           2  Vibratory........  14-inch x 89-foot                     .................
                                                                                                  steel H-piles
Existing Timber Pier Removal...  .................         * 14           15  Vibratory........  12-inch Timber     Same as above....  12-inch timber
                                                                                                  Piles.                                pile plus 14-
                                                                                                                                        inch x 89-foot
                                                                                                                                        steel H-pile.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Pier removal will overlap with work days in July to December 2020, but is kept separate as it is located north of the project area and could have more
  piles per day, though most will likely be pulled and not vibrated. Based on the rules from Table 6, vibratory pile removal at the pier would not add
  to total sound source levels when combined with the other stimuluous sources.

Level B Harassment Zones

    Transmission loss (TL) is the decrease in acoustic intensity as an 
acoustic pressure wave propagates out from a source. TL parameters vary 
with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * Log10 (R1/R2), where
TL = transmission loss in dB
B = transmission loss coefficient; for practical spreading equals 15
R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement

    The recommended TL coefficient for most nearshore environments is 
the practical spreading value of 15. This value results in an expected 
propagation environment that would lie between spherical and 
cylindrical spreading loss conditions, which is the most appropriate 
assumption for San Francisco's proposed activity.
    Using the practical spreading model, San Francisco determined 
underwater noise would fall below the behavioral effects threshold of 
120 dB rms for marine mammals at distances of 1,585 to 34,164 m 
depending on the pile type(s) and number of simultaneous vibratory 
hammers. The distance determines the maximum Level B harassment zones 
for the project. Other activities have smaller Level B harassment 
zones. It should be noted that based on the geography of Treasure 
Island, sound will not reach the full distance of the largest Level B 
harassment isopleth, except a potential sliver that would exit San 
Francisco Bay. We do not expect significant sound to exit San Francisco 
Bay however because the entrance to the bay is 13 km from the project 
location, there is extensive anthropogenic ambient noise from vessels 
and development in San Francisco that would mask the project sounds, 
and the geography and bathymetry of the bay is not conducive to sounds 
originating from Treasure Island escaping the San Francisco Bay.

                                Table 8--Level B Isopleths for Each Work Scenario
----------------------------------------------------------------------------------------------------------------
                                           Maximum exposure day                    Average exposure day
                                 -------------------------------------------------------------------------------
                                         June            July-January            June            July-January
----------------------------------------------------------------------------------------------------------------
Loudest Pile Type or Combination  2 vibratory 14-     2 vibratory 14-     2 vibratory (48-    2 vibratory 14-
                                   inch x 89-foot      inch x 89-foot      inch and 36-inch)   inch x 89-foot
                                   steel H-pile.       steel H-pile.       steel pipes.        steel H-pile *.
Level B Isolpleth (meters)......  1585..............  1585..............  34,164............  1585.
----------------------------------------------------------------------------------------------------------------
* One vibratory removal of 12-inch timber piles could be substituted for one 14-inch x 89-foot steel H-pile.
  Since source levels are identical for each type of pile, Level B isopleth distance does not change.

Level A Harassment Zones

    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that ensonified area/volume could be more 
technically challenging to predict because of the duration component in 
the new thresholds, we developed a User Spreadsheet that includes tools 
to help predict a simple isopleth that can be used in conjunction with 
marine mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which may result in some degree of 
overestimate of take by Level A harassment. However, these tools offer 
the best way to predict appropriate isopleths when more sophisticated 
3D modeling methods are not available, and NMFS continues to develop 
ways to quantitatively refine these tools, and will qualitatively 
address the output where appropriate. For stationary sources such as 
impact/vibratory pile driving or drilling, NMFS User Spreadsheet 
predicts the closest distance at which, if a marine mammal remained at 
that distance the whole duration of the activity, it would not incur 
PTS.
    Inputs used in the User Spreadsheet (Table 9), and the resulting 
isopleths are reported below (Table 10) for each of the work scenarios. 
These inputs follow the

[[Page 35285]]

rules for simultaneous pile driving as described in Table 6.

                Table 9--NMFS Technical Guidance User Spreadsheet Input To Calculate Level A Isopleths for a Combination of Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    High exposure day                                        Average exposure day
                                    --------------------------------------------------------------------------------------------------------------------
                                              June                July-January                June               July-January
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pile Type..........................  48-inch Steel Pipe      24-inch Octagonal       48-inch Steel........  14x48-inch Concrete    Vibratory Removal of
                                      Impact.                 Concrete Impact.       Pipe & 36-inch Steel    Sheet Pile Impact.     12-inch Timber Pile.
                                                                                      Simultaneous.
                                                                                     Vibratory............
Source Level (RMS SPL).............  195...................  170...................  173..................  156..................  150.
Source Level (Peak)................  210...................  189...................  .....................  167                    .....................
Number of Piles per day............  2.....................  4.....................  * 2..................  1....................  15.
Number of Strikes per Pile/Duration  225 strikes...........  1000 strikes..........  45 minutes...........  600 strikes..........  5 minutes.
 to drive.
a single pile......................
Distance of source level             10....................  10....................  10...................  33...................  15.8.
 measurement.
(m)................................
--------------------------------------------------------------------------------------------------------------------------------------------------------
Note: Propagation loss coefficient is 15LogR for all cells.
* Two combined piling events, four piles total.

    The above input scenarios lead to PTS isopleth distances (Level A 
thresholds) of 3.6 to 322.5 meters, depending on the marine mammal 
group and scenario (Table 10).

Table 10--Calculated Distances (meters) to Level A Harassment Isopleths (m) During Pile Installation and Removal
                                    for Each Hearing Group and Work Scenario
----------------------------------------------------------------------------------------------------------------
                                 Low-frequency   Mid-frequency   High-frequency       Phocid          Otariid
     Pile driving activity      cetaceans  (m)  cetaceans  (m)   cetaceans  (m)   pinnipeds  (m)  pinnipeds  (m)
----------------------------------------------------------------------------------------------------------------
                                              Maximum Exposure Day
----------------------------------------------------------------------------------------------------------------
June
    48-inch steel pipe impact.             798              28               950             427              31
July-January
    24-inch Octagonal Concrete              74               3                88              39               3
     Impact...................
----------------------------------------------------------------------------------------------------------------
                                              Average Exposure Day
----------------------------------------------------------------------------------------------------------------
June
    48-inch steel and 36-inch               57               5                84              34               2
     steel simultaneous
     vibratory................
July-January
    14x48-inch concrete sheet                8             0.3                10               4             0.3
     pile impact..............
Vibratory Removal of 12-inch                 2             0.2                 3               1             0.1
 Timber pile..................
----------------------------------------------------------------------------------------------------------------
Note: a 10-meter shutdown zone will be implemented for all species and activity types to prevent direct injury
  of marine mammals.

Marine Mammal Occurrence and Take Calculation and Estimation

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations. For the three most common species (harbor seal, 
California sea lion, and Harbor porpoise) density data exists from the 
multiple years of the San Francisco-Oakland Bay Bridge (SFOBB) 
demolition and reconstruction project (Caltrans 2015, 2018). For other 
species we used more qualitative data on observations from the SFOBB 
project and observations from year one of this project along with local 
information on strandings and other biology. Take by Level A and B 
harassment is proposed for authorization and summarized in Table 11.
    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.

Bottlenose Dolphin

    Density data for this species in the project vicinity do not exist. 
SFOBB monitoring showed two observations of this species over 6 days of 
monitoring in 2017 (CalTrans 2018). No common bottlenose dolphins were 
observed over the course of 264 monitoring hours within the 1,000 foot 
(305 m) monitoring zone for the Treasure Island Ferry Dock project in 
2019. One common bottlenose dolphin is sighted with regularity near 
Alameda (GGCR

[[Page 35286]]

2016). Based on the regularity of the sighting in Alameda and the SFOBB 
observations of approximately 0.33 dolphin a day, we propose the Level 
B harassment take equivalent to 0.33 dolphins per day for the 189 
proposed days of the project, or 63 common bottlenose dolphin. Because 
the Level A harassment zones are relatively small and we believe the 
Protected Species Observer (PSO) will be able to effectively monitor 
the Level A harassment zones, we do not anticipate or propose take by 
Level A harassment of bottlenose dolphins.

Harbor Porpoise

    Density data for this species from SFOBB monitoring was 0.17/km\2\ 
(CalTrans 2018). Based on the work scenarios of different pile types 
there are two different sized ensonified areas to be considered to 
estimate Level B harassment take (Table 12). These are the smaller area 
from simultaneous driving of the H-piles and the larger area from 
simultaneous driving of the largest pipe piles. There are 169 days of 
work for the H-pile scenario and 20 days of work for the pipe pile 
scenario. Multiplication of the above density times the corresponding 
scenario area and duration, and summing the results for the two 
scenarios leads to a proposed Level B harassment take of 537 harbor 
porpoise (Table 12).
    Given the relatively high density and large size of the Level A 
isopleths for many of the scenarios for Harbor porpoises (Table 10, 
high-frequency cetaceans) we consider Level A harassment take is a 
possibility. Based on density alone it is estimated only two harbor 
porpoises will enter a Level A harassment zone (see Table 14 of 
application). However, we recognize that harbor porpoises travel in 
groups of up to 10 individuals and observers of the Treasure Island 
Ferry Dock project in 2019 recorded two harbor porpoises over 264 hours 
of observation, or 0.008 per hour. Based on this observation we request 
take equivalent to this rate (0.008 per hour) over the entire project 
period of 189 days (10 hours per day or 1890 hours). As such, we 
propose Level A harassment take of 15 harbor porpoise.
    Because any harbor porpoises that enter the Level A harassment zone 
would initially be counted as entering the Level B harassment zone, we 
deduct the Level A harassment take form the Level B harassment take 
calculation in Table 12 to avoid double-counting and arrive at the 
proposed Level B harassment take in Table 11.

California Sea Lion

    Density data for this species from SFOBB monitoring was 0.16/km\2\ 
(CalTrans 2018). Based on the work scenarios of different pile types 
there are two different sized ensonified areas to be considered to 
estimate Level B harassment take (Table 12). These are the smaller area 
from simultaneous driving of the H-piles and the larger area from 
simultaneous driving of the largest pipe piles. There are 169 days of 
work for the H-pile scenario and 20 days of work for the pipe pile 
scenario. Multiplication of the above density times the corresponding 
scenario area and duration, and summing the results for the two 
scenarios leads to a proposed Level B harassment take of 505 California 
sea lions (Table 12).
    Given the relatively high density for California sea lions we 
consider Level A harassment take a possibility. Based on density alone 
it is estimated only one California sea lion will enter a Level A 
harassment zone (see Table 13 of application). However, we recognize 
that observers of the Treasure Island Ferry Dock project in 2019 
recorded five California sea lions over 264 hours of observation, or 
0.019 per hour. Because the observation area in 2019 is much larger 
than the small otariid Level A harassment zones we propose take at less 
than half this rate. Specifically we propose take of 15 California sea 
lions.
    Because any California sea lions that enter the Level A harassment 
zone would initially be counted as entering the Level B harassment 
zone, we deduct the Level A harassment take form the Level B harassment 
take calculation in Table 12 to avoid double-counting and arrive at the 
proposed Level B harassment take in Table 11.

Northern Fur Seal

    Density data for this species in the project vicinity do not exit. 
SFOBB monitoring showed no observations of this species (CalTrans 
2018). None were observed for the Treasure Island Ferry Dock project in 
2019. The Marine Mammal Center rescues about five northern fur seals in 
a year, and they occasionally rescue them from Yerba Buena Island and 
Treasure Island (TMMC, 2019). To be conservative we propose Level B 
harassment take of five northern fur seals. Because the Level A 
harassment zones are relatively small and we believe the PSO will be 
able to effectively monitor the Level A harassment zones, and the 
species is rare, we do not anticipate or propose take by Level A 
harassment of northern fur seals.

Northern Elephant Seal

    Density data for this species in the project vicinity do not exist. 
SFOBB monitoring showed no observations of this species (CalTrans 
2018). None were observed for the Treasure Island Ferry Dock project in 
2019. Out of the approximately 100 annual northern elephant seal 
strandings in San Francisco Bay, approximately 10 individuals strand at 
Yerba Buena or Treasure Islands each year (TMMC, 2020). Therefore, we 
propose the Level B harassment take of 10 northern elephant seals. 
Because the Level A harassment zones are relatively small and we 
believe the PSO will be able to effectively monitor the Level A 
harassment zones, and the species is rare, we do not anticipate or 
propose take by Level A harassment of northern elephant seals.

Harbor Seal

    Density data for this species from SFOBB monitoring was 3.92/km\2\ 
(CalTrans 2018). Based on the work scenarios of different pile types 
there are two different sized ensonified areas to be considered to 
estimate Level B harassment take (Table 12). These are the smaller area 
from simultaneous driving of the H-piles and the larger area from 
simultaneous driving of the largest pipe piles. There are 169 days of 
work for the H-pile scenario and 20 days of work for the pipe pile 
scenario. Multiplication of the above density times the corresponding 
scenario area and duration leads to an estimate of 13.54 harbor seals 
per day for the H-pile driving and 511 harbor seals per day for the 
pipe pile scenario. Summing the results for the two scenarios leads to 
an expectation of 12,509 instances of Level B harassment take of harbor 
seals.
    The number of expected takes per day for the pipe pile scenario 
(511) exceeds the estimate that there is only 500 harbor seals in San 
Francisco Bay (NPS 2016). It is our normal practice not to issue more 
than one take per individual per day. Therefore, we cap the number of 
takes per day for this scenario at 500 per day. Thus, summing the 
results for the two scenarios leads to a proposed Level B harassment 
take of 12,289 harbor seals (Table 12).
    Given the relatively high density and large size of the Level A 
isopleths for many of the scenarios for harbor seals (Table 10, phocid 
pinnipeds) we consider Level A harassment take is a possibility. Based 
on density alone it is estimated that nine harbor seals will enter a 
Level A harassment zone (see Table 12 of application). However, we 
recognize that harbor seals can occur in

[[Page 35287]]

moderate and rarely large size groups and observers of the Treasure 
Island Ferry Dock project in 2019 recorded 324 harbor seals over 264 
hours of observation, or 6.12 per km\2\ per hour. Most of the Level A 
take is expected to occur during the driving of the 48-inch pipe piles 
that have the largest level harassment zones (Table 10). Using the area 
of this zone of 0.27 km\2\, and seven 10-hour work days results in an 
estimate of 116 takes. As such, we propose Level A harassment take of 
116 harbor seals.
    Because any harbor seals that enter the Level A harassment zone 
would initially be counted as entering the Level B harassment zone, we 
deduct the Level A harassment take form the Level B harassment take 
calculation in Table 12 to avoid double-counting and arrive at the 
proposed Level B harassment take in Table 11.

Gray Whale

    Density data for this species in the project vicinity do not exist. 
SFOBB monitoring showed no observations of this species (CalTrans 
2018). None were observed for the Treasure Island Ferry Dock project in 
2019. Approximately 12 gray whales were stranded in San Francisco Bay 
from January to May of 2019 (TMMC, 2019). Because recent observations 
are not well understood, Treasure Island sits near the entrance to the 
bay, and as a conservative measure, we propose Level B harassment take 
of 10 gray whales. Because the Level A harassment zones are relatively 
small and we believe the PSO will be able to effectively monitor the 
Level A harassment zones, and the species is rare, we do not anticipate 
or propose take by Level A harassment of gray whales.

  Table 11--Proposed Authorized Amount of Taking, by Level A Harassment and Level B Harassment, by Species and
                                       Stock and Percent of Take by Stock
----------------------------------------------------------------------------------------------------------------
                                                                          Authorized take
                             Species                             --------------------------------   Percent of
                                                                      Level B         Level A          stock
----------------------------------------------------------------------------------------------------------------
Harbor seal (Phoca vitulina) California Stock...................          12,173             116             1.6
Harbor porpoise (Phocoena phocoena) San Francisco--Russian River             522              15             5.4
 Stock..........................................................
California sea lion (Zalophus californianus) U.S. Stock.........             490              15             0.2
Gray whale (Eschrichtius robustus) Eastern North Pacific Stock..              10               0            <0.1
Common bottlenose dolphin (Tursiops truncatus) California                     63               0            13.9
 Coastal Stock..................................................
Northern elephant seal (Mirounga angustirostris) California                   10               0            <0.1
 breeding Stock.................................................
Northern fur seal (Callorhinus ursinus) California and Eastern                 5               0            <0.1
 North Pacific Stocks...........................................
----------------------------------------------------------------------------------------------------------------


                 Table 12--Calculations of Level B Harassment Take From Density Data by Species
----------------------------------------------------------------------------------------------------------------
                                                                      Harbor      California sea
                                                                     porpoise          lion         Harbor seal
----------------------------------------------------------------------------------------------------------------
SFOBB density (animals/square km)...............................            0.17            0.16            3.96
----------------------------------------------------------------------------------------------------------------
                                  Piling Scenario/Level B isopleth Distance (m)
----------------------------------------------------------------------------------------------------------------
Days of Pile Driving
    2 vibratory 14-inch x 89-foot steel H-pile/1585 m...........             169             169             169
    2 vibratory (48-inch and 36-inch) steel pipes/34,164 m......              20              20              20
Area of Isopleth in square kilometers
    2 vibratory 14-inch x 89-foot steel H-pile/1585 m...........            3.42            3.42            3.42
    2 vibratory (48-inch and 36-inch) steel pipes/34,164 m......             129             129             129
Per day take Level B
    2 vibratory 14-inch x 89-foot steel H-pile/1585 m...........             0.6             0.5            13.5
    2 vibratory (48-inch and 36-inch) steel pipes/34,164 m......            21.9            20.6           * 500
                                                                 -----------------------------------------------
        Total Level B Take Calculated...........................             537             505          12,289
----------------------------------------------------------------------------------------------------------------
* Capped at maximum population size (500) in San Francisco Bay per day (NPS 2016).

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, and on 
the availability of the species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting the 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, 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,

[[Page 35288]]

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.
    The following mitigation measures are proposed in the IHA:
     For in-water heavy machinery work other than pile driving 
(e.g., standard barges, etc.), if a marine mammal comes within 10 m, 
operations shall cease and vessels shall reduce speed to the minimum 
level required to maintain steerage and safe working conditions. This 
type of work could include the following activities: (1) Movement of 
the barge to the pile location; or (2) positioning of the pile on the 
substrate via a crane (i.e., stabbing the pile);
     Conduct briefings between construction supervisors and 
crews and the marine mammal monitoring team prior to the start of all 
pile driving activity and when new personnel join the work, to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures;
     For those marine mammals for which Level B harassment take 
has not been requested, in-water pile installation/removal will shut 
down immediately if such species are observed within or entering the 
Level B harassment zone; and
     If take reaches the authorized limit for an authorized 
species, pile installation will be stopped as these species approach 
the Level B harassment zone to avoid additional take.
    The following mitigation measures would apply to San Francisco's 
in-water construction activities.
     Establishment of Shutdown Zones--San Francisco will 
establish shutdown zones for all pile driving and removal activities. 
The purpose of a shutdown zone is generally to define an area within 
which shutdown of the activity would occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area). 
Shutdown zones will vary based on the activity type and marine mammal 
hearing group (Table 4). The largest shutdown zones are generally for 
high frequency cetaceans, as shown in Table 13.
     The placement of PSOs during all pile driving and removal 
activities (described in detail in the Proposed Monitoring and 
Reporting section) will ensure that the entire shutdown zone is visible 
during pile installation. Should environmental conditions deteriorate 
such that marine mammals within the entire shutdown zone would not be 
visible (e.g., fog, heavy rain), pile driving and removal must be 
delayed until the PSO is confident marine mammals within the shutdown 
zone could be detected.

                          Table 13--Shutdown Zones During Pile Installation and Removal
----------------------------------------------------------------------------------------------------------------
                                 Low-frequency   Mid-frequency   High-frequency       Phocid          Otariid
     Pile driving activity         cetaceans       cetaceans        cetaceans        pinnipeds       pinnipeds
----------------------------------------------------------------------------------------------------------------
                                                High Exposure Day
----------------------------------------------------------------------------------------------------------------
June
    48-inch steel pipe impact.           * 100              30             * 100           * 100              40
July-January
    24-inch Octagonal Concrete              80              10               100              40              10
     Impact...................
----------------------------------------------------------------------------------------------------------------
                                              Average Exposure Day
----------------------------------------------------------------------------------------------------------------
June
    48-inch steel and 36-inch               60              10               100              40              10
     steel simultaneous
     vibratory................
July-January
    14 x 48-inch concrete                   10              10                10              10              10
     sheet pile impact........
Vibratory Removal of 12-inch                10              10                10              10              10
 Timber pile..................
----------------------------------------------------------------------------------------------------------------
* This shutdown zone is smaller than the Level A harassment zone. NMFS expects that PSOs will be able to monitor
  this zone more effectively, and that the smaller zone will reduce unnecessary shutdowns.

     Monitoring for Level B Harassment--San Francisco will 
monitor the Level B harassment zones and the Level A harassment zones. 
Monitoring zones provide utility for observing by establishing 
monitoring protocols for areas adjacent to the shutdown zones. 
Monitoring zones enable observers to be aware of and communicate the 
presence of marine mammals in the project area outside the shutdown 
zone and thus prepare for a potential halt of activity should the 
animal enter the shutdown zone. Placement of PSOs will allow PSOs to 
observe marine mammals within the Level B harassment zones. However, 
due to the large Level B harassment zones (Table 8), PSOs will not be 
able to effectively observe the entire zone. Therefore, Level B 
harassment exposures will be recorded and extrapolated based upon the 
number of observed takes and the percentage of the Level B harassment 
zone that was not visible.
     Pre-activity Monitoring--Prior to the start of daily in-
water construction activity, or whenever a break in pile driving/
removal of 30 minutes or longer occurs, PSOs will observe the shutdown 
and monitoring zones for a period of 30 minutes. The shutdown zone will 
be considered cleared when a marine mammal has not been observed within 
the zone for that 30-minute period. If a marine mammal is observed 
within the shutdown zone, a soft-start cannot proceed until the animal 
has left the zone or has not been observed for 15 minutes. When a 
marine mammal for which Level B harassment take is authorized is 
present in the Level B harassment zone, activities may begin and Level 
B harassment take will be recorded. If the entire Level B harassment 
zone is not visible at the start of construction, pile driving 
activities can begin. If work ceases for more than 30 minutes, the pre-
activity monitoring of the shutdown zones will commence.
     Soft Start--Soft-start procedures are believed to provide 
additional protection to marine mammals by providing warning and/or 
giving marine mammals a chance to leave the area prior to the hammer 
operating at full capacity. For impact pile driving, contractors will 
be required to provide an initial set of three strikes from the hammer 
at reduced energy, followed by a thirty-second waiting period. This

[[Page 35289]]

procedure will be conducted three times before impact pile driving 
begins. Soft start will be implemented at the start of each day's 
impact pile driving and at any time following cessation of impact pile 
driving for a period of thirty minutes or longer.
     Pile driving or removal must occur during daylight hours.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means 
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:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Visual Monitoring

    Marine mammal monitoring must be conducted in accordance with the 
Monitoring section of the application and Section 5 of the IHA. Marine 
mammal monitoring during pile driving and removal must be conducted by 
NMFS-approved PSOs in a manner consistent with the following:
     Independent PSOs (i.e., not construction personnel) who 
have no other assigned tasks during monitoring periods must be used;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
     San Francisco must submit PSO Curriculum Vitae for 
approval by NMFS prior to the onset of pile driving.
    PSOs must have the following additional qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    Two PSOs will be employed. PSO locations will provide an 
unobstructed view of all water within the shutdown zone, and as much of 
the Level A and Level B harassment zones as possible. PSO locations are 
as follows:
    (1) At the pile driving site or best vantage point practicable to 
monitor the shutdown zones; and
    (2) For the large Level B harassment zone associated with 
simultaneous driving of large pipe piles, a second PSO will be placed 
near Pier 33 in San Francisco. This PSO is not needed for other 
activities.
    Monitoring will be conducted 30 minutes before, during, and 30 
minutes after pile driving/removal activities. In addition, observers 
shall record all incidents of marine mammal occurrence, regardless of 
distance from activity, and shall document any behavioral reactions in 
concert with distance from piles being driven or removed. Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving or drilling equipment is no more than 30 minutes.

Reporting

    A draft marine mammal monitoring report will be submitted to NMFS 
within 90 days after the completion of pile driving and removal 
activities, or 60 days prior to a requested date of issuance of any 
future IHAs for projects at the same location, whichever comes first. 
The report will include an overall description of work completed, a 
narrative regarding marine mammal sightings, and associated PSO data 
sheets. Specifically, the report must include:
     Dates and times (begin and end) of all marine mammal 
monitoring.
     Construction activities occurring during each daily 
observation period, including how many and what type of piles were 
driven or removed and by what method (i.e., impact or vibratory).
     Weather parameters and water conditions during each 
monitoring period (e.g., wind speed, percent cover, visibility, sea 
state).
     The number of marine mammals observed, by species, 
relative to the pile location and if pile driving or removal was 
occurring at time of sighting.
     Age and sex class, if possible, of all marine mammals 
observed.
     PSO locations during marine mammal monitoring.
     Distances and bearings of each marine mammal observed to 
the pile being driven or removed for each sighting (if pile driving or 
removal was occurring at time of sighting).
     Description of any marine mammal behavior patterns during 
observation, including direction of travel and estimated time spent 
within the Level A and Level B harassment zones while the source was 
active.

[[Page 35290]]

     Number of individuals of each species (differentiated by 
month as appropriate) detected within the monitoring zone, and 
estimates of number of marine mammals taken, by species (a correction 
factor may be applied to total take numbers, as appropriate).
     Detailed information about any implementation of any 
mitigation triggered (e.g., shutdowns and delays), a description of 
specific actions that ensued, and resulting behavior of the animal, if 
any.
     Description of attempts to distinguish between the number 
of individual animals taken and the number of incidences of take, such 
as ability to track groups or individuals.
     An extrapolation of the estimated takes by Level B 
harassment based on the number of observed exposures within the Level B 
harassment zone and the percentage of the Level B harassment zone that 
was not visible, when applicable.
    If no comments are received from NMFS within 30 days, the draft 
final report will constitute the final report. If comments are 
received, a final report addressing NMFS comments must be submitted 
within 30 days after receipt of comments.

Reporting Injured or Dead Marine Mammals

    In the event that personnel involved in the construction activities 
discover an injured or dead marine mammal, San Francisco shall report 
the incident to the Office of Protected Resources (OPR), NMFS and to 
the regional stranding coordinator as soon as feasible. If the death or 
injury was clearly caused by the specified activity, San Francisco must 
immediately cease the specified activities until NMFS is able to review 
the circumstances of the incident and determine what, if any, 
additional measures are appropriate to ensure compliance with the terms 
of the IHA. The IHA-holder must not resume their activities until 
notified by NMFS. The report must include the following information:
     Time, date, and location (latitude/longitude) of the first 
discovery (and updated location information if known and applicable);
     Species identification (if known) or description of the 
animal(s) involved;
     Condition of the animal(s) (including carcass condition if 
the animal is dead);
     Observed behaviors of the animal(s), if alive;
     If available, photographs or video footage of the 
animal(s); and
     General circumstances under which the animal was 
discovered.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), 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's 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 environmental 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, this introductory discussion of our analyses 
applies to all of the species listed in Table 11, given that many of 
the anticipated effects of this project on different marine mammal 
stocks are expected to be relatively similar in nature. Additional 
discussion is included for harbor seals, which occur more densely in 
the area and may be disturbed repeatedly during the season. Pile 
driving activities have the potential to disturb or displace marine 
mammals. Specifically, the project activities may result in take, in 
the form of Level A harassment and Level B harassment from underwater 
sounds generated from pile driving and removal. Potential takes could 
occur if individuals are present in the ensonified zone when these 
activities are underway.
    The takes from Level A and Level B harassment would be due to 
potential behavioral disturbance, TTS, and PTS. No mortality is 
anticipated given the nature of the activity and measures designed to 
minimize the possibility of injury to marine mammals. The potential for 
harassment is minimized through the construction method and the 
implementation of the planned mitigation measures (see Proposed 
Mitigation section).
    The Level A harassment zones identified in Table 10 are based upon 
an animal exposed to impact pile driving multiple piles per day. 
Considering duration of impact driving each pile (up to 10 minutes) and 
breaks between pile installations (to reset equipment and move pile 
into place), this means an animal would have to remain within the area 
estimated to be ensonified above the Level A harassment threshold for 
multiple hours. This is highly unlikely given marine mammal movement 
throughout the area. If an animal was exposed to accumulated sound 
energy, the resulting PTS would likely be small (e.g., PTS onset) at 
lower frequencies where pile driving energy is concentrated, and 
unlikely to result in impacts to individual fitness, reproduction, or 
survival.
    The nature of the pile driving project precludes the likelihood of 
serious injury or mortality. For all species and stocks, take would 
occur within a limited, confined area (western San Francisco Bay) of 
any given stock's range. Level A and Level B harassment will be reduced 
to the level of least practicable adverse impact through use of 
mitigation measures described herein. Further the amount of take 
proposed to be authorized for any given stock is extremely small when 
compared to stock abundance.
    Behavioral responses of marine mammals to pile driving at the 
project site, if any, are expected to be mild and temporary. Marine 
mammals within the Level B harassment zone may not show any visual cues 
they are disturbed by activities (as noted during modification to the 
Kodiak Ferry Dock) or could become alert, avoid the area, leave the 
area, or display other mild responses that are not observable such as 
changes in vocalization patterns. Given the short duration of noise-
generating activities per day and that pile driving and removal would 
occur across six months, any harassment would be temporary. There are 
no other areas or times of known biological importance for any of the 
affected species.
    We are authorizing large numbers of take of harbor seals. As 
discussed above, there are approximately 500 harbor seals in San 
Francisco Bay. Thus we expect most of the harbor seal take to consist 
of repeated take of a smaller number of

[[Page 35291]]

individuals, rather than a large proportion of the stock. Most of the 
take is expected to occur from the 20 days of simultaneous vibratory 
pile driving of large piles. However, we are not concerned about 
fitness impacts as the daily exposure is likely to be brief and 
intermittent. The 20 days of simultaneous pile driving are not expected 
to be sequential, providing the animals recovery time. The presence of 
the large simultaneous level B harassment zones are also likely to be 
of very short duration within a day on any given day given the dynamics 
of operating and adjusting different pile driving rigs and thus the 
likelihood that both rigs will be operating simultaneously. It is also 
the case that some of the simultaneous pile driving will consist of one 
large pile and smaller, quieter H-piles (see Table 7), so that effects 
are likely to be less significant. In addition, this area of the bay 
lacks important habitat areas, including haulouts within the level B 
harassment zone, and the existing industrialized nature and loud 
ambient noise of the area minimize the degradation of habitat and 
effects on individual fitness, reproduction, or survival. Moreover, 
harbor seals resident in San Francisco Bay are likely habituated to 
this noise and activity as evident in the low number of observed 
responses, none of which seemed severe, from monitoring. Finally, the 
status of this stock is not of concern.
    In addition, it is unlikely that minor noise effects in a small, 
localized area of habitat would have any effect on the stocks' ability 
to recover. In combination, we believe that these factors, as well as 
the available body of evidence from other similar activities, 
demonstrate that the potential effects of the specified activities will 
have only minor, short-term effects on individuals. The specified 
activities are not expected to impact rates of recruitment or survival 
and will therefore not result in population-level impacts.
    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:
     No mortality is anticipated or authorized.
     Authorized Level A harassment would be very small amounts 
and of low degree.
     No biologically important areas have been identified 
within the project area.
     For all species, San Francisco Bay is a very small and 
peripheral part of their range.
     For harbor seals take is concentrated in a small number of 
individuals with the 20 days of major activity spread out, the most 
severe simultaneous pile driving likely of short duration on any given 
day in an area of unimportant habitat with significant exiting 
anthropomorphic noise and disturbance and evidence the animals are 
habituated to these circumstances.
     San Francisco would implement mitigation measures such as 
vibratory driving piles to the maximum extent practicable, soft-starts, 
and shut downs.
     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.
    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 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 Section 101(a)(5)(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 of all species or 
stocks is below one third of the estimated stock abundance. These are 
all likely conservative estimates because they assume all takes are of 
different individual animals which is likely not the case. Some 
individuals may return multiple times in a day, but PSOs would count 
them as separate takes if they cannot be individually identified.
    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 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 (ESA)

    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, in this case with the West Coast Region 
Protected Resources Division Office, 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 an IHA to San Francisco to conduct the Treasure Island Ferry Dock 
project in San Francisco, CA for one year from the date of issuance, 
provided the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated. A draft of the proposed IHA 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 authorization, and 
any other aspect of this Notice of Proposed IHA for the proposed 
Treasure Island Ferry Dock project. We also request at this time 
comment on the potential renewal of this proposed IHA as

[[Page 35292]]

described in the paragraph below. Please include with your comments any 
supporting data or literature citations to help inform decisions on the 
request for this IHA or a subsequent Renewal IHA.
    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 
Activity section of this notice is planned or (2) the activities as 
described in the Description of Proposed Activity 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:
     A request for renewal is received no later than 60 days 
prior to the needed Renewal IHA effective date (recognizing that 
Renewal IHA expiration date cannot extend beyond one year from 
expiration of the initial IHA);
     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); 
and
    (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; and
     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: June 3, 2020.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2020-12363 Filed 6-8-20; 8:45 am]
 BILLING CODE 3510-22-P