Taking of Marine Mammals Incidental to Specific Activities; Taking of Marine Mammals Incidental To Pile Driving Activities During Construction of a Ferry Terminal at Seaplane Lagoon, Alameda Point, San Francisco, California, 34347-34371 [2019-15299]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 84, Number 138 (Thursday, July 18, 2019)]
[Notices]
[Pages 34347-34371]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2019-15299]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XR009


Taking of Marine Mammals Incidental to Specific Activities; 
Taking of Marine Mammals Incidental To Pile Driving Activities During 
Construction of a Ferry Terminal at Seaplane Lagoon, Alameda Point, 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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[[Page 34348]]

SUMMARY: NMFS has received a request from the City of Alameda (City) 
for authorization to take marine mammals incidental to pile driving 
activities during construction of a ferry terminal at Seaplane Lagoon, 
Alameda Point, 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 August 
19, 2019.

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: Stephanie Egger, 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 such 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 such takings are set forth.

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 
incidental harassment authorization) with respect to potential impacts 
on the human environment. This action is consistent with categories of 
activities identified in Categorical Exclusion B4 (incidental 
harassment authorizations 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 22, 2019, NMFS received a request from the City for an 
IHA to take marine mammals incidental to pile driving activities during 
construction of a ferry terminal in Seaplane Lagoon, Alameda, 
California. The application was deemed adequate and complete on June 
28, 2019. The applicant's request is for take seven species of marine 
mammals by Level B harassment only. Neither the City nor NMFS expects 
serious injury or mortality to result from this activity and, 
therefore, an IHA is appropriate.

Description of Proposed Activity

Overview

    The purpose of this project is to provide facilities to expand the 
existing ferry service from Alameda and Oakland to San Francisco in 
order to address the limited capacity at the existing Main Street Ferry 
Terminal, accommodate the anticipated increase in demand for ferry 
service from Alameda to San Francisco due to planned development of the 
Alameda Point Project, and to provide enhanced emergency response 
services to Alameda in the event of transbay service disruptions.
    Currently, the nearest operational ferry terminal to Alameda Point 
is the Alameda Main Street Terminal along the Oakland Alameda Estuary. 
There is also a ferry terminal that serves Oakland's Jack London 
Square. Both of these terminals are owned and operated by the San 
Francisco Bay Area Water Emergency Transportation Authority (WETA). 
Peak time ferry service demand is at capacity. It is not unusual for 
passengers to be left behind at Alameda during the morning commutes, 
and parking demand at the facility currently outstrips available 
spaces. Ferry ridership at the Alameda Main Street WETA terminal is 
currently at 94 percent capacity and rose 12 percent in the last 
calendar year. WETA and the City intend to establish a commute-oriented 
ferry service between Seaplane Lagoon and San Francisco once operating 
funds and terminal and vessel assets are secured to operate the 
expansion service.
    The Project encompasses both landside and waterside components;

[[Page 34349]]

however, the in-water work components are discussed in this document. 
Please refer to the application for more information on landside 
components.
    The in-water sound from the pile driving and removal activities, 
may incidentally take seven species of marine mammals by Level B 
harassment only.

Dates and Duration

    Project construction is proposed to begin in during early August 
2019 and will be completed within approximately one year of initiation. 
All of the in-water work (float installation with piles and gangway) is 
expected to be completed within one environmental work season (August 1 
to November 30). Construction will occur during weekdays and on 
weekends if needed. Site preparation and ground improvements will occur 
over one month, and could overlap with in-water work. Construction of 
landside improvements will require approximately 4 to 6 months. 
Approximately 24 total days of pile driving activities are estimated to 
occur, with 12 days of vibratory hammering installation and removal for 
template piles, 6 days of vibratory hammering for permanent piles, and 
6 days of impact hammering for permanent piles. These are discussed in 
further detail below.

Specific Geographic Region

    Seaplane Lagoon is located at the western end of Alameda Island 
within the 150-acre Waterfront Town Center area of Alameda Point and on 
the former Alameda Point Naval Air Station in Alameda, California. The 
project area is located along the eastern shoreline of Seaplane Lagoon, 
west of Ferry Point, south of West Atlantic Avenue, and north of West 
Oriskany Avenue (Figure 1).
    Seaplane Lagoon is a rectangular basin approximately 3,000 feet 
(ft) by 1,600 ft. Breakwaters protect the basin from wind-generated 
waves, providing typically calm conditions. Seaplane Lagoon is bordered 
by an existing concrete and steel sheet pile bulkhead to the north, 
rock slope revetments to the east and west, and a breakwater with a 
600-ft opening to the south. The proposed location of the ferry 
terminal is on the eastern shoreline of the lagoon.

[[Page 34350]]

[GRAPHIC] [TIFF OMITTED] TN18JY19.085

Detailed Description of Specific Activity

    The Project encompasses both landside and waterside components, 
including the construction and operation of a new ferry terminal along 
the eastern edge of Seaplane Lagoon (see Figure 3 of the application). 
Only waterside components are discussed below. Please see the 
application for information on landside components.
    A pier and abutment are required at the entrance to the ferry 
terminal to provide secure and safe entry from the land to the 
passenger access gangway (see Figure 3 of the application). The pier 
will extend out from the abutment to provide sufficient depth for the 
ferry vessels and float. The abutment will be located on the shoreline 
and will consist of a concrete abutment (24 feet (ft) long by 3 ft 
wide) supported on steel piles. The pier will be placed in the water 
and consist of a cast-in-place concrete structure (83.1 ft long by 20 
ft wide) supported on piles with a perimeter guardrail. Approximately 
six 24-inch (in) diameter octagonal concrete piles offshore of the 
revetment and four 24-in diameter steel piles inshore of the revetment 
will be used for the pier. The abutment and pier deck will be installed 
above the high tide line.
    The pier will be covered by a canopy similar to those on other San 
Francisco Bay Area WETA terminals in the San Francisco Bay Area. 
Dimensions would be longer than the pier by 16 ft (100 ft long by 20 ft 
wide), with an approximate height of 8.5 ft to 20 ft above the pier 
deck. The additional length would overhang the pier landside and shade 
the stairs up to the pier.
    A gangway will connect the pier to the boarding float. The aluminum 
gangway (90 ft long by 10 ft wide) will

[[Page 34351]]

be supported on the landside end of the pier by cantilevered seat 
supports, and the waterside end of the gangway will be supported by a 
boarding float. The finished walking surface, which will consist of 
fiberglass micromesh decking, will range in elevation from 8.4 ft at 
the pier to approximately 4.4 ft above the water surface on the 
boarding float.
    The Seaplane Lagoon Ferry Terminal will include a boarding float 
where passengers will board and disembark from the ferry (see Figure 3 
of the application). The float structure will be a steel pontoon barge 
(135 ft long by 42 ft wide by 8 ft deep) with internal compartments. 
Fenders and mooring cleats will be located around the perimeter of the 
float to accommodate vessel berthing scenarios. The float will be held 
in position with an arrangement of four 36-in diameter steel guide 
piles and two 36-in diameter steel fender piles, totaling six piles.
    Piles will be installed for the abutment, pier, and float. The 36-
in steel piles will be installed with a vibratory hammer, 24-in 
concrete piles will be installed with an impact hammer, and 14-in steel 
template piles will be installed with a vibratory hammer (see Table 1 
below). The abutment piles will be installed from the landside, and are 
expected to require an impact hammer to penetrate the underlying 
material. Four steel piles (the abutment piles) will be installed above 
the high tide line and therefore are not discussed further.
    Template piles will be used to support the in-water piles. These 
will consist of 12 to 18 14-inch steel H-type piles (see Table 1 
below). One template typically includes four piles, but up to six 
template piles would be used at one time (see Table 1 below).

                 Table 1--Pile Driving and Removal Activities for Seaplane Lagoon Ferry Terminal
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                                                                         Project component
                                                 ---------------------------------------------------------------
                   Description                       Temporary       Temporary
                                                   template pile   template pile  Permanent pile  Permanent pile
                                                   installation       removal      installation    installation
----------------------------------------------------------------------------------------------------------------
Diameter of Steel Pile (inches).................              14              14              24              36
# of Piles......................................              18              18               6               6
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                                             Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
Total Quantity..................................              18              18               0               6
Max # Piles Vibrated per Day....................               6               6               0               1
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                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
Total Quantity..................................               0               0               6               0
Max # Piles Impacted per Day....................               0               0               1               0
----------------------------------------------------------------------------------------------------------------

    For further details on the proposed action and project components, 
please refer to the application.
    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 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 
follow Committee on Taxonomy (2016). 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 and SARs (Carretta et al., 2018). All values 
presented in Table 2 are the most recent available at the time of 
publication (draft SARS available online at: https://www.fisheries.noaa.gov/national/marine-mammal-protection/draft-marine-mammal-stock-assessment-reports).

[[Page 34352]]



                                                 Table 2--Marine Mammals Occurrence in the Project Area
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                                                                                 ESA/MMPA       Stock abundance
                                                                                  status;       (CV, Nmin, most                                Annual M/
           Common name                Scientific name           Stock          strategic (Y/   recent  abundance               PBR               SI \3\
                                                                                  N) \1\          survey) \2\
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                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Eschrichtiidae:
    Gray whale...................  Eschrichtius          Eastern North        -/- ; N         26,960 (0.05,        801.......................        138
                                    robustus.             Pacific.                             25,849, 2016).
Family Balaenopteridae
 (rorquals):
    Humpback whale...............  Megaptera             California/Oregon/   E/D ; Y         2,900 (0.048,        16.7 (U.S. waters)........       18.8
                                    novaeangliae.         Washington.                          2,784, 2014).
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                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae:
    Bottlenose dolphin...........  Tursiops truncatus..  California Coastal.  -/- ; N         453 (0.06, 346,      2.7.......................         >2
                                                                                               2011).
Family Phocoenidae (porpoises):
    Harbor porpoise..............  Phocoena phocoena...  San Francisco-       -/- ; N         9,886 (0.51, 6,625,  66........................          0
                                                          Russian River.                       2011).
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                                                         Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California sea lion..........  Zalophus              U.S................  -/- ; N         257,606 (n/a,        14,011....................      >=319
                                    californianus.                                             233,515, 2014).
    Northern fur seal............  Callorhinus ursinus.  California.........  -/- ; N         14,050 (n/a, 7,524,  451.......................        1.8
                                                         Eastern North        -/- ; N          2013).              11,405....................        1.1
                                                          Pacific.                            626,734 (n/a,
                                                                                               530,474, 2014).
    Guadalupe fur seal...........  Arctocephalus         Mexico to            T/D ; Y         20,000 (n/a,         542.......................       >3.2
                                    townsendi.            California.                          15,830, 2010).
Family Phocidae (earless seals):
    Pacific harbor seal..........  Phoca vitulina        California.........  -/- ; N         30,968 (n/a,         1,641.....................         43
                                    richardii.                                                 27,348, 2012).
    Northern elephant seal.......  Mirounga              California Breeding  -/- ; N         179,000 (n/a,        4,882.....................        8.8
                                    angustirostris.                                            81,368, 2010).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species or stock listed
  under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ NMFS marine mammal stock assessment reports online at: www.nmfs.noaa.gov/pr/sars/. CV is coefficient of variation; Nmin is the minimum estimate of
  stock abundance. In some cases, CV is not applicable [explain if this is the case].
\3\ These values, found in NMFS's SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g.,
  commercial fisheries, ship strike). Annual M/SI 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.
NOTE--Italicized species are not expected to be taken or proposed for authorization.

    All species that could potentially occur in the proposed survey 
areas are included in Table 2. However, the temporal and/or spatial 
occurrence of humpback whales and Guadalupe fur seals is such that take 
is not expected to occur, and they are not discussed further beyond the 
explanation provided here.
    Humpback whales do enter San Francisco Bay to feed on schooling 
fish from late April through October, but are rarer visitors to the 
interior of San Francisco Bay. A recent, seasonal influx of humpback 
whales inside San Francisco Bay near the Golden Gate was recorded from 
April to November in 2016 and 2017 (Keener 2017). In May and June 2019, 
a lone humpback was observed in the waters off Alameda; however, this 
is a rare occurrence and the whale was thought to be in poor health. 
The whale was observed on May 27, 2019 in the Alameda Seaplane Lagoon, 
where it remained until June 5, 2019. It was determined to be an adult, 
and malnourished, based on the thin blubber layer. On June 6, 2019, the 
whale re-located to an area outside the Seaplane Lagoon, but still 
within the breakwater protecting the Alameda ferry docks and the USS 
Hornet. It remained there for 8 days, exhibiting the same suite of 
behaviors seen in the Seaplane Lagoon. On June 14, 2019, it left 
Alameda and moved farther out towards the main opening of the 
breakwater, near the open bay (The Marine Mammal Center (TMMC), B. 
Keener, pers. comm. 2019) and has not been observed since. It is 
unlikely that this humpback whale will be in the waters off Alameda 
when the project begins. NMFS does expect take to occur.
    Guadalupe fur seals occasionally range into the waters of northern 
California and the Pacific Northwest. The Farallon Islands (off central 
California) and Channel Islands (off southern California) are used as 
haul outs during these movements (Simon 2016). Juvenile Guadalupe fur 
seals occasionally strand in the vicinity of San Francisco, especially 
during El Ni[ntilde]o events. Most strandings along the California 
coast are animals younger than two years old, with evidence of 
malnutrition (NMFS 2017a). Because Guadalupe fur seals are highly rare 
in the area, and sightings are associated with abnormal weather 
conditions, such as El Ni[ntilde]o events, NMFS has determined that no 
Guadalupe fur seals are likely to occur in the project vicinity and, 
therefore, no take is expected to occur.

Gray Whale

    Gray whales are large baleen whales. They grow to approximately 50 
ft in length and weigh up to 40 tons. They are one of the most 
frequently seen whales along the California coast, easily recognized by 
their mottled gray color and lack of dorsal fin. Adult whales carry 
heavy loads of attached barnacles,

[[Page 34353]]

which add to their mottled appearance. Gray whales are divided into the 
Eastern North Pacific and Western North Pacific stocks. Both stocks 
migrate each year along the west coast of continental North America and 
Alaska. The Eastern North Pacific stock is much larger and is more 
likely to occur in the San Francisco Bay area. Western North Pacific 
Gray whales have summer and fall feeding grounds in the Okhotsk Sea off 
northeast Sakhalin Island, Russia, and off southeastern Kamchatka in 
the Bering Sea (NMFS 2017).
    Gray whales are the only baleen whale known to feed on the sea 
floor, where they scoop up bottom sediments to filter out benthic 
crustaceans, mollusks, and worms (NMFS 2015). They feed in northern 
waters primarily off the Bering, Chukchi, and western Beaufort Seas 
during the summer. Between December and January, late-stage pregnant 
females, adult males, and immature females and males migrate southward 
to breeding areas around Mexico. The northward migration occurs between 
February and March. Coastal waters just outside San Francisco Bay are 
considered a migratory Biologically Important Area for the northward 
progression of gray whales (Calambokidis et al., 2015). During this 
time, recently pregnant females, adult males, immature females, and 
females with calves move north to the feeding grounds (Calambokidis et 
al., 2014). A few individuals enter into the San Francisco Bay during 
their northward migration. Foraging individuals in the San Francisco 
Bay may occur in small numbers in waters adjacent to Alameda Point, 
outside of the breakwaters, typically from December to May.
    Since January 1, 2019, elevated gray whale strandings have occurred 
along the west coast of North America from Mexico through Alaska. This 
event has been declared an Unusual Mortality Event. As of June 21, 
2019, 37 gray whales have stranded in California. Full or partial 
necropsy examinations were conducted on a subset of the whales. 
Preliminary findings in several of the whales have shown evidence of 
emaciation. These findings are not consistent across all of the whales 
examined, so more research is needed.

Bottlenose Dolphins

    Bottlenose dolphins are distributed world-wide in tropical and 
warm-temperate waters. In many regions, including California, separate 
coastal and offshore populations are known (Walker 1981; Ross and 
Cockcroft 1990; Van Waerebeek et al. 1990). The California coastal 
stock of bottlenose dolphins is distinct from the offshore stock, based 
on significant differences in genetics and cranial morphology (Perrin 
et al. 2011, Lowther-Thielking et al. 2015). California coastal 
bottlenose dolphins are found within about one kilometer (km) of shore 
(Hansen, 1990; Carretta et al. 1998; Defran and Weller 1999) with the 
range extending north over the last several decades related to El 
Ni[ntilde]o events and increased ocean temperatures. As the range of 
bottlenose dolphins extended north, dolphins began entering the Bay in 
2010 (Szczepaniak 2013). Until 2016, most bottlenose dolphins in San 
Francisco Bay were observed in the western Bay, from the Golden Gate 
Bridge to Oyster Point and Redwood City (Perlman 2017). Members of the 
California Coastal stock are transient and make movements up and down 
the coast into some estuaries, throughout the year.

Harbor Porpoise

    Harbor porpoise are seldom found in waters warmer than 62.6 degrees 
Fahrenheit (17 degrees Celsius) (Read 1990) or south of Point 
Conception, and occurs as far north as the Bering Sea (Barlow and Hanan 
1995; Carretta et al., 2017). The San Francisco-Russian River stock is 
found from Pescadero, 18 mi (30 km) south of the Bay, to 99 mi (160 km) 
north of the Bay at Point Arena (Carretta et al., 2017). In most areas, 
harbor porpoise occurs in small groups, consisting of just a few 
individuals.
    Occasional sightings of harbor porpoises in the Bay, including near 
the Yerba Buena Island harbor seal haul[hyphen]out site, were reported 
by the Caltrans marine mammal monitoring program beginning in 2008 
(Caltrans 2018). Continued sightings from Caltrans and the Golden Gate 
Cetacean Research (GGCR) Organization suggests that the species is 
returning to San Francisco Bay after an absence of approximately 65 
years (GGCR 2010). This re[hyphen]immergence is not unique to San 
Francisco Bay, but rather indicative of the harbor porpoise in general 
along the west coast. GGCR has been issued a scientific research permit 
from NMFS for a multi[hyphen]year assessment to document the population 
abundance and distribution in the Bay (82 FR 60374). Recent 
observations of harbor porpoises have been reported by GGCR researchers 
off Cavallo Point, outside Raccoon Strait between Tiburon and Angel 
Island, off Fort Point and as far into the Bay as Carquinez Strait 
(Perlman 2010). Based on the Caltrans and GGCR monitoring, over 100 
porpoises were seen at one time entering San Francisco Bay; and over 
600 individual animals have been documented in a photo[hyphen]ID 
database. Reported sightings are concentrated in the vicinity of the 
Golden Gate Bridge and Angel Island, with lesser numbers sighted south 
of Alcatraz and west of Treasure Island (AECOM 2017).

Harbor Seal

    Harbor seals are found from Baja California to the eastern Aleutian 
Islands of Alaska. The species primarily hauls out on remote mainland 
and island beaches and reefs, and estuary areas. Harbor seals tend to 
forage locally within 53 miles (mi) (85 km) of haul-out sites (Harvey 
and Goley 2011). Harbor seal is the most common marine mammal species 
observed in the Bay and individuals are commonly seen near the San 
Francisco-Oakland Bay Bridge east span (CalTrans 2013b, 2013c). Tagging 
studies have shown that most seals tagged in the Bay remain in the Bay 
(Harvey and Goley 2011; Manugian 2013). Foraging often occurs in the 
Bay, as noted by observations of seals exhibiting foraging behavior 
(short dives less than five minutes, moving back and forth in an area, 
and sometimes tearing up prey at the surface). Moderate to small 
numbers are known to forage in Seaplane Lagoon.
    Although solitary in the water, harbor seals come ashore at haul 
outs to rest, socialize, breed, nurse, molt, and thermoregulate. 
Habitats used as haul out sites include tidal rocks, bayflats, 
sandbars, and sandy beaches (Zeiner et al., 1990). Haul out sites are 
relatively consistent from year to year (Kopec and Harvey 1995) and 
females have been recorded returning to their own natal haul out to 
breed (Cunningham et al., 2009). Although harbor seals haul out at 
approximately 20 locations around San Francisco Bay, there are three 
primary sites: Mowry Slough in the South Bay, Corte Madera Marsh and 
Castro Rocks in the North Bay, and Yerba Buena Island in the Central 
Bay (Grigg 2008; Gibble 2011). Yerba Buena Island haul out is located 
approximately five mi north project area. Harbor seals use Yerba Buena 
Island year-round, with the largest numbers seen during winter months, 
when Pacific herring spawn (Grigg 2008). Two known pinniped haul-out 
sites in the vicinity of the project area are located on an existing 
haul out platform approximately 0.5 mi southeast of the project area 
(separated from project activities by approximately 0.3 mi of developed 
areas on-land), and at the western end of Breakwater Island, 
approximately 1.0 mi southwest of the pile driving activities (see 
Figure 4 of the application).

[[Page 34354]]

California Sea Lion

    California sea lions breed on the offshore islands of California 
from May through July (Heath and Perrin 2009). During the non-breeding 
season, adult and sub-adult 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 (Lowry and Forney 2005; Heath and Perrin 2009). 
Females and some juveniles tend to remain closer to rookeries 
(Antonelis et al., 1990; Melin et al., 2008).
    In San Francisco Bay, California sea lions have been observed at 
Angel Island and occupying the docks near Pier 39 which is the largest 
California sea lion haul[hyphen]out in San Francisco Bay. A maximum of 
1,706 sea lions were counted at Pier 39 in 2009. However, since then 
the population has averaged at about 50-300 depending upon the season 
(TMMC 2017). This group of sea lions has decreased in size in recent 
years, coincident with a fluctuating decrease in the herring population 
in the Bay. There are no known breeding sites within San Francisco Bay. 
Their primary breeding site is in the Channel Islands (USACE 2011). The 
sea lions appear at Pier 39 after returning from the Channel Islands at 
the beginning of August (Bauer 1999). No other sea lion haul out sites 
have been identified in the Bay and no pupping has been observed at the 
Pier 39 site or any other site in San Francisco Bay under normal 
conditions (USACE 2011). Although there has been documentation of 
pupping on docks in the Bay, this event was during a domoic acid event. 
There is no reason to anticipate that any domoic events will occur 
during the project construction activities.
    The project site is approximately 4 mi away from Pier 39. Although 
there is little information regarding the foraging behavior of the 
California sea lion in southern San Francisco Bay, they have been 
observed foraging on a regular basis in the shipping channel south of 
Yerba Buena Island.
    Foraging grounds have also been identified for pinnipeds, including 
sea lions, between Yerba Buena Island and Treasure Island, as well as 
off the Tiburon Peninsula (Caltrans, 2006). The California sea lions 
that use the Pier 39 haul[hyphen]out site may be feeding on Pacific 
herring (Clupea harengus), northern anchovy, and other prey in the 
waters of San Francisco Bay (Caltrans, 2013a). In addition to the Pier 
39 haul[hyphen]out, California sea lions haul out on buoys and similar 
structures throughout San Francisco Bay. They mainly are seen swimming 
off the San Francisco and Marin shorelines within San Francisco Bay, 
but may occasionally enter the project area to forage and could 
possibly haul-out on nearby breakwater islands or platforms.

Northern Elephant Seal

    The northern elephant seal is 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 the 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. 
Pups of the year return in the late summer and fall, to haul out at 
breeding rookery and small haul out sites, but occasionally they may 
make brief stops in the Bay.
    Generally, only juvenile elephant seals enter the Bay and do not 
remain long. The most recent sighting near the project area was in 
2012, on the beach at Clipper Cove on Treasure Island (5 mi north of 
the project area), when a healthy yearling elephant seal hauled out for 
approximately 1 day. Approximately 100 juvenile northern elephant seals 
strand in or near the Bay each year, including individual strandings at 
Yerba Buena Island and Treasure Island (less than 10 strandings per 
year).

Northern Fur Seal

    Northern fur seal breeds on the offshore islands of California and 
in the Bering Sea from May through July. Two stocks of Northern fur 
seals may occur near the Bay, the California and Eastern Pacific 
stocks. The California stock breeds, pups, and forages off the 
California coast. The Eastern Pacific stock breeds and pups on islands 
in the Bering Sea, but females and juveniles move south to California 
waters to forage in the fall and winter months.
    Both the California and Eastern Pacific stocks forage in the 
offshore waters of California, but only sick, emaciated, or injured fur 
seals enter the Bay. The Marine Mammal Center (TMMC) occasionally picks 
up stranded fur seals around Yerba Buena Island and Treasure Island.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. Marine mammal hearing 
groups and their associated hearing ranges are provided in Table 3.

[[Page 34355]]



                  Table 3--Marine Mammal Hearing Groups
                               [NMFS 2018]
------------------------------------------------------------------------
            Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen   7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans           150 Hz to 160 kHz.
 (dolphins, toothed whales, beaked
 whales, bottlenose whales).
High-frequency (HF) cetaceans (true    275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus
 cruciger & L. australis).
Phocid pinnipeds (PW) (underwater)     50 Hz to 86 kHz.
 (true seals).
Otariid pinnipeds (OW) (underwater)    60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al. 2007) and PW pinniped (approximation).

    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt, 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2018) for a review of available information. 
Seven marine mammal species (3 cetacean and 4 pinniped (2 otariid and 2 
phocid) species) have the reasonable potential to occur during the 
proposed activities. Please refer to Table 2. Of the cetacean species 
that may be present, one is classified as low-frequency cetacean (i.e., 
all mysticete species), one is classified as mid-frequency cetacean 
(i.e., all delphinid species), and one is classified as high-frequency 
cetacean (i.e., harbor porpoise).

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 by Incidental Harassment 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 by Incidental Harassment 
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 the City's proposed activities have the potential 
to result in Level B harassment of marine mammals in the vicinity of 
the action area.

Description of Sound Sources

    This section contains a brief technical background on sound, on the 
characteristics of certain sound types, and on metrics used in this 
proposal inasmuch as the information is relevant to the specified 
activity and to a discussion of the potential effects of the specified 
activity on marine mammals found later in this document. For general 
information on sound and its interaction with the marine environment, 
please see, e.g., Au and Hastings (2008); Richardson et al. (1995); 
Urick (1983).
    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz (Hz) or cycles per second. Wavelength is the 
distance between two peaks or corresponding points of a sound wave 
(length of one cycle). Higher frequency sounds have shorter wavelengths 
than lower frequency sounds, and typically attenuate (decrease) more 
rapidly, except in certain cases in shallower water. Amplitude is the 
height of the sound pressure wave or the ``loudness'' of a sound and is 
typically described using the relative unit of the decibel (dB). A 
sound pressure level (SPL) in dB is described as the ratio between a 
measured pressure and a reference pressure (for underwater sound, this 
is 1 microPascal ([mu]Pa)), and is a logarithmic unit that accounts for 
large variations in amplitude; therefore, a relatively small change in 
dB corresponds to large changes in sound pressure. The source level 
(SL) represents the SPL referenced at a distance of 1 m from the source 
(referenced to 1 [mu]Pa), while the received level is the SPL at the 
listener's position (referenced to 1 [mu]Pa).
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick, 1983). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper, 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures.
    Sound exposure level (SEL; represented as dB re 1 [mu]Pa\2\-s) 
represents the total energy in a stated frequency band over a stated 
time interval or event, and considers both intensity and duration of 
exposure. The per-pulse SEL is calculated over the time window 
containing the entire pulse (i.e., 100 percent of the acoustic energy). 
SEL is a cumulative metric; it can be accumulated over a single pulse, 
or calculated over periods containing multiple pulses. Cumulative SEL 
represents the total energy accumulated by a receiver over a defined 
time window or during an event. Peak sound pressure (also referred to 
as zero-to-peak sound pressure or 0-pk) is the maximum instantaneous 
sound pressure measurable in the water at a specified distance from the 
source, and is represented in the same units as the rms sound pressure.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in a 
manner similar to ripples on the surface of a pond and may be either 
directed in a beam or beams or may radiate in all directions

[[Page 34356]]

(omnidirectional sources), as is the case for sound produced by the 
pile driving activity considered here. The compressions and 
decompressions associated with sound waves are detected as changes in 
pressure by aquatic life and man-made sound receptors such as 
hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound, which is 
defined as environmental background sound levels lacking a single 
source or point (Richardson et al., 1995). The sound level of a region 
is defined by the total acoustical energy being generated by known and 
unknown sources. These sources may include physical (e.g., wind and 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
(e.g., vessels, dredging, construction) sound. A number of sources 
contribute to ambient sound, including wind and waves, which are a main 
source of naturally occurring ambient sound for frequencies between 200 
hertz (Hz) and 50 kilohertz (kHz) (Mitson, 1995). In general, ambient 
sound levels tend to increase with increasing wind speed and wave 
height. Precipitation can become an important component of total sound 
at frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times. Marine mammals can contribute significantly to ambient sound 
levels, as can some fish and snapping shrimp. The frequency band for 
biological contributions is from approximately 12 Hz to over 100 kHz. 
Sources of ambient sound related to human activity include 
transportation (surface vessels), dredging and construction, oil and 
gas drilling and production, geophysical surveys, sonar, and 
explosions. Vessel noise typically dominates the total ambient sound 
for frequencies between 20 and 300 Hz. In general, the frequencies of 
anthropogenic sounds are below 1 kHz and, if higher frequency sound 
levels are created, they attenuate rapidly.
    The sum of the various natural and anthropogenic sound sources that 
comprise ambient sound at any given location and time depends not only 
on the source levels (as determined by current weather conditions and 
levels of biological and human 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 decibels (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.
    Sounds are often considered to fall into one of two general types: 
Pulsed and non-pulsed (defined in the following). 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). Please see 
Southall et al. (2007) for an in-depth discussion of these concepts. 
The distinction between these two sound types is not always obvious, as 
certain signals share properties of both pulsed and non-pulsed sounds. 
A signal near a source could be categorized as a pulse, but due to 
propagation effects as it moves farther from the source, the signal 
duration becomes longer (e.g., Greene and Richardson, 1988).
    Pulsed sound sources (e.g., airguns, explosions, gunshots, sonic 
booms, impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986, 2005; Harris, 1998; NIOSH, 1998; ISO, 2003) and occur 
either as isolated events or repeated in some succession. Pulsed sounds 
are all characterized by a relatively rapid rise from ambient pressure 
to a maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or intermittent (ANSI, 1995; 
NIOSH, 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems. The 
duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment.
    The impulsive sound generated by impact hammers is characterized by 
rapid rise times and high peak levels. Vibratory hammers produce non-
impulsive, continuous noise at levels significantly lower than those 
produced by impact hammers. Rise time is slower, reducing the 
probability and severity of injury, and sound energy is distributed 
over a greater amount of time (e.g., Nedwell and Edwards, 2002; Carlson 
et al., 2005).

Acoustic Effects on Marine Mammals

    We previously provided general background information on marine 
mammal hearing (see Description of Marine Mammals in the Area of the 
Specified Activity). Here, we discuss the potential effects of sound on 
marine mammals.
    Note that, in the following discussion, we refer in many cases to a 
review article concerning studies of noise-induced hearing loss 
conducted from 1996-2015 (i.e., Finneran, 2015). For study-specific 
citations, please see that work. Anthropogenic sounds cover a broad 
range of frequencies and sound levels and can have a range of highly 
variable impacts on marine life, from none or minor to potentially 
severe responses, depending on received levels, duration of exposure, 
behavioral context, and various other factors. The potential effects of 
underwater sound from active acoustic sources can potentially result in 
one or more of the following: Temporary or permanent hearing 
impairment, non-auditory physical or physiological effects, behavioral 
disturbance, stress, and masking (Richardson et al., 1995; Gordon et 
al., 2004; Nowacek et al., 2007; Southall et al., 2007; G[ouml]tz et 
al., 2009). The degree of effect is intrinsically related to the signal 
characteristics, received level, distance from the source, and duration 
of the sound exposure. In general, sudden, high level sounds can cause 
hearing loss, as can longer exposures to lower level sounds. Temporary 
or permanent loss of hearing will occur almost exclusively for noise 
within an animal's hearing range. We first describe specific 
manifestations of acoustic effects before providing discussion specific 
to pile driving and removal activities.
    Richardson et al. (1995) described zones of increasing intensity of 
effect that might be expected to occur, in relation to distance from a 
source and assuming that the signal is within an animal's hearing 
range. First is the area within which the acoustic signal would be 
audible (potentially perceived) to the animal but not strong enough to 
elicit any overt behavioral or physiological

[[Page 34357]]

response. The next zone corresponds with the area where the signal is 
audible to the animal and of sufficient intensity to elicit behavioral 
or physiological responsiveness. Third is a zone within which, for 
signals of high intensity, the received level is sufficient to 
potentially cause discomfort or tissue damage to auditory or other 
systems. Overlaying these zones to a certain extent is the area within 
which masking (i.e., when a sound interferes with or masks the ability 
of an animal to detect a signal of interest that is above the absolute 
hearing threshold) may occur; the masking zone may be highly variable 
in size.
    We describe the more severe effects (i.e., certain non-auditory 
physical or physiological effects) only briefly as we do not expect 
that there is a reasonable likelihood that pile driving may result in 
such effects (see below for further discussion). Potential effects from 
explosive impulsive sound sources can range in severity from effects 
such as behavioral disturbance or tactile perception to physical 
discomfort, slight injury of the internal organs and the auditory 
system, or mortality (Yelverton et al., 1973). Non-auditory 
physiological effects or injuries that theoretically might occur in 
marine mammals exposed to high level underwater sound or as a secondary 
effect of extreme behavioral reactions (e.g., change in dive profile as 
a result of an avoidance reaction) caused by exposure to sound include 
neurological effects, bubble formation, resonance effects, and other 
types of organ or tissue damage (Cox et al., 2006; Southall et al., 
2007; Zimmer and Tyack, 2007; Tal et al., 2015). The construction 
activities considered here do not involve the use of devices such as 
explosives or mid-frequency tactical sonar that are associated with 
these types of effects.
    Threshold Shift--Marine mammals exposed to high-intensity sound, or 
to lower-intensity sound for prolonged periods, can experience hearing 
threshold shift (TS), which is the loss of hearing sensitivity at 
certain frequency ranges (Finneran, 2015). TS can be permanent (PTS), 
in which case the loss of hearing sensitivity is not fully recoverable, 
or temporary (TTS), in which case the animal's hearing threshold would 
recover over time (Southall et al., 2007). Repeated sound exposure that 
leads to TTS could cause PTS. In severe cases of PTS, there can be 
total or partial deafness, while in most cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter, 
1985).
    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward, 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, and there is no PTS data for cetaceans, but such 
relationships are assumed to be similar to those in humans and other 
terrestrial mammals. PTS typically occurs at exposure levels at least 
several decibels above (a 40-dB threshold shift approximates PTS onset; 
e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS (a 6-dB 
threshold shift approximates TTS onset; e.g., Southall et al. 2007). 
Based on data from terrestrial mammals, a precautionary assumption is 
that the PTS thresholds for impulse sounds (such as impact pile driving 
pulses as received close to the source) are at least 6 dB higher than 
the TTS threshold on a peak-pressure basis and PTS cumulative sound 
exposure level thresholds are 15 to 20 dB higher than TTS cumulative 
sound exposure level thresholds (Southall et al., 2007). Given the 
higher level of sound or longer exposure duration necessary to cause 
PTS as compared with TTS, it is considerably less likely that PTS could 
occur.
    TTS is the mildest form of hearing impairment that can occur during 
exposure to sound (Kryter, 1985). While experiencing TTS, the hearing 
threshold rises, and a sound must be at a higher level in order to be 
heard. In terrestrial and marine mammals, TTS can last from minutes or 
hours to days (in cases of strong TTS). In many cases, hearing 
sensitivity recovers rapidly after exposure to the sound ends. Few data 
on sound levels and durations necessary to elicit mild TTS have been 
obtained for marine mammals.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. 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. 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 occurs during a time 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.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis)) and three species of pinnipeds (northern elephant 
seal, harbor seal, and California sea lion) exposed to a limited number 
of sound sources (i.e., mostly tones and octave-band noise) in 
laboratory settings (Finneran, 2015). TTS was not observed in trained 
spotted (Phoca largha) and ringed (Pusa hispida) seals exposed to 
impulsive noise at levels matching previous predictions of TTS onset 
(Reichmuth et al., 2016). In general, harbor seals and harbor porpoises 
have a lower TTS onset than other measured pinniped or cetacean species 
(Finneran, 2015). Additionally, the existing marine mammal TTS data 
come from a limited number of individuals within these species. There 
are no data 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 NMFS (2018).
    Behavioral Effects--Behavioral disturbance may include a variety of 
effects, including subtle changes in behavior (e.g., minor or brief 
avoidance of an area or changes in vocalizations), more conspicuous 
changes in similar behavioral activities, and more sustained and/or 
potentially severe reactions, such as displacement from or abandonment 
of high-quality habitat. 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

[[Page 34358]]

sources, distance from the source). Please see Appendices B-C of 
Southall et al. (2007) for a review of studies involving marine mammal 
behavioral responses to sound.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance (Bejder et al., 2009). The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. As noted, behavioral state may affect the type of response. 
For example, animals that are resting may show greater behavioral 
change in response to disturbing sound levels than animals that are 
highly motivated to remain in an area for feeding (Richardson et al., 
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with 
captive marine mammals have showed pronounced behavioral reactions, 
including avoidance of loud sound sources (Ridgway et al., 1997; 
Finneran et al., 2003). Observed responses of wild marine mammals to 
loud pulsed sound sources (typically airguns or acoustic harassment 
devices) have been varied but often consist of avoidance behavior or 
other behavioral changes suggesting discomfort (Morton and Symonds, 
2002; see also Richardson et al., 1995; Nowacek et al., 2007). However, 
many delphinids approach low-frequency airgun source vessels with no 
apparent discomfort or obvious behavioral change (e.g., Barkaszi et 
al., 2012), indicating the importance of frequency output in relation 
to the species' hearing sensitivity.
    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). However, there are broad categories of potential response, which 
we describe in greater detail here, that include alteration of dive 
behavior, alteration of foraging behavior, effects to breathing, 
interference with or alteration of vocalization, avoidance, and flight.
    Changes in dive behavior can vary widely and may consist of 
increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive (e.g., Frankel 
and Clark, 2000; Costa et al., 2003; Ng and Leung, 2003; Nowacek et 
al.; 2004; Goldbogen et al., 2013a, 2013b). Variations in dive behavior 
may reflect interruptions in biologically significant activities (e.g., 
foraging) or they may be of little biological significance. The impact 
of an alteration to dive behavior resulting from an acoustic exposure 
depends on what the animal is doing at the time of the exposure and the 
type and magnitude of the response.
    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.
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure (e.g., Kastelein et al., 2001, 2005, 2006; Gailey et 
al., 2007; Gailey et al., 2016).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors, and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
are known to change direction--deflecting from customary migratory 
paths--in order to avoid noise from airgun surveys (Malme et al., 
1984). Avoidance may be short-term, with animals returning to the area 
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996; 
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007). 
Longer-term displacement is possible, however, which may lead to 
changes in abundance or distribution patterns of the affected species 
in the affected region if habituation to the presence of the sound does 
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann 
et al., 2006).
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, although observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus, 1996). The result of a flight response could range from 
brief, temporary exertion and displacement

[[Page 34359]]

from the area where the signal provokes flight to, in extreme cases, 
marine mammal strandings (Evans and England, 2001). However, it should 
be noted that response to a perceived predator does not necessarily 
invoke flight (Ford and Reeves, 2008), and whether individuals are 
solitary or in groups may influence the response.
    Behavioral disturbance can also impact marine mammals in more 
subtle ways. Increased vigilance may result in costs related to 
diversion of focus and attention (i.e., when a response consists of 
increased vigilance, it may come at the cost of decreased attention to 
other critical behaviors such as foraging or resting). These effects 
have generally not been demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (e.g., Beauchamp and 
Livoreil, 1997; Fritz et al., 2002; Purser and Radford, 2011). In 
addition, chronic disturbance can cause population declines through 
reduction of fitness (e.g., decline in body condition) and subsequent 
reduction in reproductive success, survival, or both (e.g., Harrington 
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption 
of such functions resulting from reactions to stressors such as sound 
exposure are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multi-day 
substantive behavioral reactions and multi-day anthropogenic 
activities. For example, just because an activity lasts for multiple 
days does not necessarily mean that individual animals are either 
exposed to activity-related stressors for multiple days or, further, 
exposed in a manner resulting in sustained multi-day substantive 
behavioral responses.
    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).
    Auditory 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; Erbe et al., 
2016). 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., 
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.
    Under certain circumstances, marine mammals experiencing 
significant masking could also be impaired from maximizing their 
performance fitness in survival and reproduction. Therefore, when the 
coincident (masking) sound is man-made, it may be considered harassment 
when disrupting or altering critical behaviors. It is important to 
distinguish TTS and PTS, which persist after the sound exposure, from 
masking, which occurs during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by

[[Page 34360]]

anthropogenic noise may be considered as a reduction in the 
communication space of animals (e.g., Clark et al., 2009) and may 
result in energetic or other costs as animals change their vocalization 
behavior (e.g., Miller et al., 2000; Foote et al., 2004; Parks et al., 
2007; Di Iorio and Clark, 2009; Holt et al., 2009). Masking can be 
reduced in situations where the signal and noise come from different 
directions (Richardson et al., 1995), through amplitude modulation of 
the signal, or through other compensatory behaviors (Houser and Moore, 
2014). Masking can be tested directly in captive species (e.g., Erbe, 
2008), but in wild populations it must be either modeled or inferred 
from evidence of masking compensation. There are few studies addressing 
real-world masking sounds likely to be experienced by marine mammals in 
the wild (e.g., Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial shipping 
(Hildebrand, 2009). All anthropogenic sound sources, but especially 
chronic and lower-frequency signals (e.g., from vessel traffic), 
contribute to elevated ambient sound levels, thus intensifying masking.
    Potential Effects of the City's Activity--As described previously 
(see Description of Active Acoustic Sound Sources), the City proposes 
to conduct pile driving, including impact and vibratory driving. The 
effects of pile driving on marine mammals are dependent on several 
factors, including the size, type, and depth of the animal; the depth, 
intensity, and duration of the pile driving sound; the depth of the 
water column; the substrate of the habitat; the standoff distance 
between the pile and the animal; and the sound propagation properties 
of the environment. With both types, it is likely that the pile driving 
could result in temporary, short term changes in an animal's typical 
behavioral patterns and/or avoidance of the affected area. These 
behavioral changes may include (Richardson et al., 1995): 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; and/or flight responses.
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, or reproduction. Significant 
behavioral modifications that could lead to effects on growth, 
survival, or reproduction, such as drastic changes in diving/surfacing 
patterns or significant habitat abandonment are extremely unlikely in 
this area (i.e., shallow waters in modified industrial areas).
    Whether impact or vibratory driving, sound sources would be active 
for relatively short durations, with relation to potential for masking. 
The frequencies output by pile driving activity are lower than those 
used by most species expected to be regularly present for communication 
or foraging. We expect insignificant impacts from masking, and any 
masking event that could possibly rise to Level B harassment under the 
MMPA would occur concurrently within the zones of behavioral harassment 
already estimated for vibratory and impact pile driving, and which have 
already been taken into account in the exposure analysis.

Anticipated Effects on Marine Mammal Habitat

    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals except the actual footprint of 
the project. The footprint of the project is small, and equal to the 
area the ferry associated pile placement. The installation of piles for 
the new pier will result in permanent impacts on 61 square feet (ft\2\) 
of aquatic habitat. At best, the impact area, which is located in 
Seaplane Lagoon, provides marginal foraging habitat for marine mammals 
and fish. The net loss of such a small area (25 ft\2\) of benthic 
habitat is not expected to impair the health of these species or affect 
their populations. Project construction and long-term operation are not 
expected to disturb nearby harbor seal haul-outs, which are located 1.0 
mi to the southwest on Breakwater Island and 0.5 mi to the southeast on 
a platform installed by the City.
    The proposed activities may have potential short-term impacts to 
food sources such as forage fish. The proposed activities could also 
affect acoustic habitat (see masking discussion above), but meaningful 
impacts are unlikely. There are no known foraging hotspots, or other 
ocean bottom structures of significant biological importance to marine 
mammals present in the marine waters in the vicinity of the project 
areas. Therefore, the main impact issue associated with the proposed 
activity would be temporarily elevated sound levels and the associated 
direct effects on marine mammals, as discussed previously. The most 
likely impact to marine mammal habitat occurs from pile driving effects 
on likely marine mammal prey (i.e., fish) near where the piles are 
installed. Impacts to the immediate substrate during installation and 
removal of piles are anticipated, but these would be limited to minor, 
temporary suspension of sediments, which could impact water quality and 
visibility for a short amount of time, but which would not be expected 
to have any effects on individual marine mammals. Impacts to substrate 
are therefore not discussed further.
    Effects to 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 and, for some, is not well documented. 
Here, we describe studies regarding the effects of noise on known 
marine mammal prey.
    Fish utilize the soundscape and components of sound in their 
environment to perform important functions such as foraging, predator 
avoidance, mating, and spawning (e.g., Zelick et al., 1999; Fay, 2009). 
Depending on their hearing anatomy and peripheral sensory structures, 
which vary among species, fishes hear sounds using pressure and 
particle motion sensitivity capabilities and detect the motion of 
surrounding water (Fay et al., 2008). The potential effects of noise on 
fishes depends on the overlapping frequency range, distance from the 
sound source, water depth of exposure, and species-specific hearing 
sensitivity, anatomy, and physiology. Key impacts to fishes may include 
behavioral responses, hearing damage, barotrauma (pressure-related 
injuries), and mortality.
    Fish react to sounds which are especially strong and/or 
intermittent low-frequency sounds, and behavioral responses such as 
flight or avoidance are the most likely effects. Short duration, sharp 
sounds can cause overt or subtle changes in fish behavior and local 
distribution. The reaction of fish to

[[Page 34361]]

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). More commonly, though, the 
impacts of noise on fish are temporary.
    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 action area supports marine habitat for prey species including 
large populations of anadromous fish including Pacific salmon (five 
species), cutthroat and steelhead trout, and Dolly Varden (NMFS 2018) 
and other species of marine fish such as halibut, rock sole, sculpins, 
Pacific cod, herring, and eulachon (NMFS 2018). The most likely impact 
to fish from pile driving activities at the project areas would be 
temporary behavioral avoidance of the area. The duration of fish 
avoidance of an area after pile driving stops is unknown, but a rapid 
return to normal recruitment, distribution and behavior is anticipated. 
In general, impacts to marine mammal prey species are expected to be 
minor and temporary due to the expected short daily duration of 
individual pile driving events and the relatively small areas being 
affected.
    The area impacted by the project is relatively small compared to 
the available habitat in San Francisco Bay. 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. As 
described in the preceding, the potential for the City's construction 
to affect the availability of prey to marine mammals or to meaningfully 
impact the quality of physical or acoustic habitat is considered to be 
insignificant. Effects to habitat will not be discussed further in this 
document.

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.
    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).
    Take of marine mammals incidental to the City's pile driving and 
removal activities could occur as a result of Level B harassment. Below 
we describe how the potential take is estimated. 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). 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--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 [mu]Pa (rms) 
for continuous (e.g., vibratory pile driving) and above 160 dB re 1 
[mu]Pa (rms) for impulsive sources (e.g., impact pile driving). The 
City'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) are applicable.
    Level A harassment--NMFS' Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Version 2.0) 
(Technical Guidance, 2018) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise. The 
technical guidance identifies the received levels, or thresholds, above 
which individual marine mammals are predicted to experience changes in 
their hearing sensitivity for all underwater anthropogenic sound 
sources, and reflects the best available science on the potential for 
noise to affect auditory sensitivity by:
    [ssquf] Dividing sound sources into two groups (i.e., impulsive and 
non-

[[Page 34362]]

impulsive) based on their potential to affect hearing sensitivity;
    [ssquf] Choosing metrics that best address the impacts of noise on 
hearing sensitivity, i.e., sound pressure level (peak SPL) and sound 
exposure level (SEL) (also accounts for duration of exposure); and
    [ssquf] Dividing marine mammals into hearing groups and developing 
auditory weighting functions based on the science supporting that not 
all marine mammals hear and use sound in the same manner.
    These thresholds were developed by compiling and synthesizing the 
best available science, and are provided in Table 4 below. The 
references, analysis, and methodology used in the development of the 
thresholds are described in NMFS 2018 Technical Guidance, which may be 
accessed at https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
    The City's pile driving and removal activity includes the use of 
impulsive (impact pile driving) and non-impulsive (vibratory pile 
driving and removal) sources.

                                         Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
                                                                    (Auditory Injury)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                         PTS Onset Acoustic Thresholds *  (received level)
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Hearing group                                           Impulsive                                             Non-impulsive
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low-Frequency (LF) Cetaceans............     Cell 1                                                            Cell 2
                                          Lpk,flat: 219 dB; LE,LF,24h: 183 dB                               LE,LF,24h: 199 dB
Mid-Frequency (MF) Cetaceans............     Cell 3                                                            Cell 4
                                          Lpk,flat: 230 dB; LE,MF,24h: 185 dB                               LE,MF,24h: 198 dB
High-Frequency (HF) Cetaceans...........     Cell 5                                                            Cell 6
                                          Lpk,flat: 202 dB; LE,HF,24h: 155 dB                               LE,HF,24h: 173 dB
Phocid Pinnipeds (PW) (Underwater)......     Cell 7                                                            Cell 8
                                          Lpk,flat: 218 dB; LE,PW,24h: 185 dB                               LE,PW,24h: 201 dB
Otariid Pinnipeds (OW) (Underwater).....     Cell 9                                                            Cell 10
                                          Lpk,flat: 232 dB; LE,OW,24h: 203 dB                               LE,OW,24h: 219 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 [mu]Pa, and cumulative sound exposure level (LE) has a reference value of 1[mu]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.

Sound Propagation

    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:

B = transmission loss coefficient (assumed to be 15)
R1 = the distance of the modeled SPL from the driven 
pile, and
R2 = the distance from the driven pile of the initial 
measurement.

    This formula neglects loss due to scattering and absorption, which 
is assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20*log(range)). Cylindrical spreading occurs 
in an environment in which sound propagation is bounded by the water 
surface and sea bottom, resulting in a reduction of 3 dB in sound level 
for each doubling of distance from the source (10*log(range)). As is 
common practice in coastal waters, here we assume practical spreading 
loss (4.5 dB reduction in sound level for each doubling of distance). 
Practical spreading is a compromise that is often used under conditions 
where water depth increases as the receiver moves away from the 
shoreline, resulting in an expected propagation environment that would 
lie between spherical and cylindrical spreading loss conditions.

Sound Source Levels

    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. There are source level 
measurements available for certain pile types and sizes from the 
similar environments recorded from underwater pile driving projects 
(CALTRANS 2015) that were evaluated and used as proxy sound source 
levels to determine reasonable sound source levels likely result from 
the City's pile driving and removal activities (Table 5). Many source 
levels used were more conservation as the values were from larger pile 
sizes.

[[Page 34363]]



                 Table 5--Predicted Sound Source Levels
------------------------------------------------------------------------
                                   Sound source
           Activity                level at 10          Sound source
                                      meters
------------------------------------------------------------------------
                     Vibratory Pile Driving/Removal
------------------------------------------------------------------------
14-inch H pile steel pile       155 SPL..........  CALTRANS 2015 (12-in
 temporary.                                         H piles sound source
                                                    value used, as no 14-
                                                    in H pile sound
                                                    source level is
                                                    available)
36-inch steel pile permanent..  170 SPL..........  CALTRANS 2015
------------------------------------------------------------------------
                           Impact Pile Driving
------------------------------------------------------------------------
24-inch concrete pile           166 SEL/176 SPL..  CALTRANS 2015
 permanent.
------------------------------------------------------------------------
Notes: These are unattentuated values, as the applicant proposes to use
  a bubble curtain for a 7dB reduction for impact driving.

Level A Harassment

    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 Level A harassment take. 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 from 
impact and vibratory pile driving), 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 (Tables 6 and 7), and the resulting isopleths 
are reported below (Table 8).

    Table 6--NMFS Technical Guidance (2018) User Spreadsheet Input to
           Calculate PTS Isopleths for Vibratory Pile Driving
------------------------------------------------------------------------
   User Spreadsheet Input--Vibratory Pile Driving; Spreadsheet Tab A.1
                       Vibratory Pile Driving Used
-------------------------------------------------------------------------
                                           14-in H piles
                                            (temporary      36-in piles
                                             install/       (permanent)
                                             removal)
------------------------------------------------------------------------
Source Level (RMS SPL)..................             155             170
Weighting Factor Adjustment (kHz).......             2.5             2.5
Number of piles within 24-hr period.....               6               2
Duration to drive a single pile (min)...               4              30
Propagation (xLogR).....................              15              15
Distance of source level measurement                  10              10
 (meters) [dagger]......................
------------------------------------------------------------------------


    Table 7--NMFS Technical Guidance (2018) User Spreadsheet Input To
             Calculate PTS Isopleths for Impact Pile Driving
------------------------------------------------------------------------
 User Spreadsheet Input--Impact Pile Driving;Spreadsheet Tab E.1 Impact
                           Pile Driving Used.
-------------------------------------------------------------------------
                                                          24-in concrete
                                                               piles
                                                            (permanent)
------------------------------------------------------------------------
Source Level (Single Strike/shot SEL)...................           * 159
Weighting Factor Adjustment (kHz).......................               2
Number of strikes per pile..............................            3100
Number of piles per day.................................               1
Propagation (xLogR).....................................              15
Distance of source level measurement (meters) *.........              10
------------------------------------------------------------------------
* This includes the 7dB reduction from use of a bubble curtain.


[[Page 34364]]


                     Table 8--NMFS Technical Guidance (2018) User Spreadsheet Outputs to Calculate Level A Harassment PTS Isopleths
--------------------------------------------------------------------------------------------------------------------------------------------------------
                        User Spreadsheet Output                                                       PTS isopleths (meters)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                        Level A harassment
                                                                        --------------------------------------------------------------------------------
                 Activity                   Sound source level at 10 m    Low-frequency   Mid-frequency   High-frequency
                                                                            cetaceans       cetaceans        cetaceans        Phocid          Otariid
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Vibratory Pile Driving/Removal
--------------------------------------------------------------------------------------------------------------------------------------------------------
14-in H pile steel installation/removal..  155 dB SPL..................             1.5              0.1             2.2             0.9             0.1
36-in steel permanent installation.......  170 dB SPL..................            13.1              1.2            19.3             7.9             0.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Impact Pile Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in concrete permanent installation....  166 SEL/176 SPL (159 dB SEL             53.3              1.9            63.5            28.5             2.1
                                            as attenuated).
--------------------------------------------------------------------------------------------------------------------------------------------------------

Level B Harassment

    Utilizing the practical spreading loss model, the City determined 
underwater noise will fall below the behavioral effects threshold of 
120 dB rms for marine mammals at the distances shown in Table 9 for 
vibratory pile driving/removal. For calculating the Level B Harassment 
Zone for impact driving, the practical spreading loss model was used 
with a behavioral threshold of 160 dB rms for marine mammals at the 
distances shown in Table 9 for impact pile driving. Table 9 below 
provides all Level B Harassment radial distances (m) and their 
corresponding areas (km\2\) during the City's proposed activities.

   Table 9--Radial Distances (meters) to Relevant Behavioral Isopleths and Associated Ensonified Areas (square
                             kilometers (km\2\)) Using the Practical Spreading Model
----------------------------------------------------------------------------------------------------------------
                                                                                      Level B         Level B
                   Activity                          Received level at 10 m         harassment      harassment
                                                                                    zone  (m) *    zone  (km\2\)
----------------------------------------------------------------------------------------------------------------
                                         Vibratory Pile Driving/Removal
----------------------------------------------------------------------------------------------------------------
14-inch H piles installation/removal..........  155 dB SPL......................           2,154           2.190
36-inch steel permanent installation..........  170 dB SPL......................          21,544           21.49
----------------------------------------------------------------------------------------------------------------
                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
24-inch concrete permanent installation.......  166 dB..........................            39.8           0.004
                                                SEL/176 dB......................
                                                SPL (169 dB.....................
                                                SPL attenuated).................
----------------------------------------------------------------------------------------------------------------

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. Potential exposures to impact pile driving and vibratory 
pile driving/removal for each acoustic threshold were estimated using 
group size estimates and local observational data to create a density 
estimate. As previously stated, take by Level B harassment only will be 
considered for this action. Distances to Level A harassment thresholds 
are relatively small and mitigation is expected to avoid Level A 
harassment from these activities.
Gray Whales
    There are no density estimates of gray whales available in the 
project area. Gray whales travel alone or in small, unstable groups, 
although large aggregations may be seen in feeding and breeding grounds 
(NMFS 2018). Gray whales are uncommon in the San Francisco Bay. It is 
estimated that approximately 2-6 individuals enter the bay in a typical 
year (CALTRANS 2018). However nine gray whales have stranded in the San 
Francisco Bay in 2019 (Katz 2019). To be conservative, NMFS proposes to 
authorize seven instances of take by Level B harassment of gray whales. 
Because the required shutdown measures are larger than the associated 
Level A harassment zones, and those zones are relatively small (53.3 m 
at the largest during impact pile driving), and activities will occur 
over a small number of days, we believe the PSO will be able to 
effectively monitor the Level A harassment zones and we do not 
anticipate take by Level A harassment of gray whales.
Bottlenose Dolphin
    There are no density estimates of Bottlenose dolphin available in 
the project area. Individuals in the San Francisco Bay are typically 
sighted near the Golden Gate Bridge, where an average of five dolphins 
enter the bay approximately three times annually. Two individuals are 
sighted regularly near Alameda Point, outside of the Seaplane Lagoon 
(CALTRANS 2018). Low numbers (ranging from 1 to 5) of individually 
identified coastal bottlenose dolphins have been seen

[[Page 34365]]

along the southwest side of Alameda Island since July 2016. Much of the 
time, the dolphins were close to the south side of the main outer 
breakwater that separates the bay from the lagoon areas. The last 
reliable sighting there was April 7, 2019 of a single individual (TMMC, 
B. Keener pers. comm. 2019). For the purpose of this assessment it is 
predicted that two bottlenose dolphins may occur in the San Francisco 
Bay in the Project vicinity on all pile driving days (i.e., up to 48 
individuals in 24 days. Therefore, NMFS proposes to authorize 48 
instances of take of bottlenose dolphin by Level B harassment. The 
Level A harassment zones are all under 2 m for mid-frequency cetaceans; 
therefore, no take by Level A harassment is anticipated.
Harbor Porpoise, Harbor Seals, and California Sea Lions
    In-water densities of harbor porpoises, harbor seals, California 
sea lions were calculated based on 17 years of observations during 
monitoring for the San Francisco Bay-Oakland Bay Bridge (SFOBB) 
construction and demolition project (Caltrans 2018). Care was taken to 
eliminate multiple observations of the same animal, although this can 
be difficult and is likely that the same individual may have been 
counted multiple times on the same day. The amount of monitoring 
performed per year varied, depending on the frequency and duration of 
construction activities with the potential to affect marine mammals. 
During the 257 days of monitoring from 2000 through 2017 (including 15 
days of baseline monitoring in 2003), 1,029 harbor seals, 83 California 
sea lions, and 24 harbor porpoises were observed in waters in the 
project vicinity in total. In 2015, 2016, and 2017, the number of 
harbor seals in the project area increased significantly. A California 
sea lion density estimate of 0.161 animals/km\2\ was calculated using 
the data from 2000-2017. In 2017, the number of harbor porpoise in the 
project area also increased significantly. Therefore, a harbor seal 
density estimate of 3.957 animals/km\2\ was calculated using the 2015-
2017 data. A harbor porpoise density estimate of 0.167 animals/km\2\ 
was calculated using the 2017 data, which may better reflect the 
current use of the project area by these animals. These observations 
included data from baseline, pre-, during, and post-pile driving, 
mechanical dismantling, on-shore blasting, and off-shore implosion 
activities.
    In addition to the information provided above regarding harbor seal 
density estimates, harbor seals are known to use the tip of Breakwater 
Island, which is located approximately 1.0 mi southwest of the project 
area, as a haul-out site. These seals forage in the project area as 
well (WETA 2011). In recent years, up to 32 harbor seals have been 
observed making irregular use of the Breakwater Island haul-out (AECOM 
2017). The City of Alameda has also recently installed a haul-out 
platform approximately 0.5 mi southeast of the site. Although these 
locations are not considered primary haul-outs for harbor seals due to 
the relatively low numbers of individuals that are present, Breakwater 
Island and the City haul-out platform are reportedly the only haul-out 
sites in the central Bay that are accessible to seals throughout the 
full tidal range.
    A local group of Alameda Point Harbor Seal Monitors regularly 
counts the number of harbor seals at Alameda Point, and based on count 
data from 2014 to 2019 an average of 11.7 harbor seals is present at 
Alameda Point year-round (Bangert pers. comm. 2019 in the application). 
However, the numbers of harbor seals present in the area varies 
considerably with season, with higher numbers in the winter due to the 
presence of spawning Pacific herring (Clupea pallasii) in the San 
Francisco Bay. Project pile driving activities will occur during the 
months of August and September, and therefore we estimated the average 
number of harbor seals based on count data these months only. The data 
summary indicated that the numbers of harbor seals present at Alameda 
increased in 2017 and 2018 compared to 2015 and 2016, and therefore 
only count data from 2017 and 2018 was used to ensure that the density 
estimate reflects current conditions. The average number of harbor 
seals counted at Alameda Point in August and September of 2017 and 2018 
was 6.5 individuals. These densities described above for harbor 
porpoise, harbor seals, and California sea lions are then used to 
calculate estimated take and described in the sub-sections below for 
these species.

Harbor Porpoise

    A predicted density of 0.167 animals/km\2\ based for harbor 
porpoise was used to estimate take (Table 10). The estimated take was 
calculated using this density multiplied by the area ensonified above 
the threshold multiplied by the number of days per activity (e.g., 6 
days of impact pile driving) (Table 10). Therefore, a total of 26 
instances of take by Level B harassment are proposed for harbor 
porpoise. Because the required shutdown measures are larger than the 
associated Level A harassment zones, and the harassment zones ar not 
very larger (63.5 m at the largest during impact pile driving), and 
will only occur over a small number of days, we believe the PSO can 
effectively monitor the Level A harassment zones and therefore we do 
not anticipate take by Level A harassment of harbor porpoise.

                   Table 10--Proposed Estimated Take by Level B Harassment of Harbor Porpoise
----------------------------------------------------------------------------------------------------------------
                                                      Density                                        Proposed
                     Source                          (animals/     Area  (km\2\)      Days of      Level B  take
                                                      km\2\)                         activity     by  harassment
----------------------------------------------------------------------------------------------------------------
Vibratory Installation and Removal 14-in H piles           0.167           2.190              12           4.389
Vibratory 36-in piles...........................           0.167          21.490               6          21.533
Impact 24-in piles..............................           0.167           0.004               6           0.004
                                                 ---------------------------------------------------------------
    Total Take by Level B harassment............  ..............  ..............  ..............          25.926
                                                                                                     (rounded to
                                                                                                             26)
----------------------------------------------------------------------------------------------------------------

Harbor Seal

    A predicted a density of 3.957 animals/km\2\ for harbor seals was 
used to estimate take by Level B harassment (Table 11). This density 
should account for harbor seals exposed in the water while moving to 
and from the breakwater haul out since those animals would be in the 
bay and accounted for

[[Page 34366]]

by the density estimate. The estimated take was calculated using this 
density multiplied by the area ensonified above the threshold 
multiplied by the number of days per activity (e.g., 6 days of impact 
pile driving) (Table 11). Therefore, a total of 615 instances of take 
by Level B harassment are proposed for harbor seals. Because the 
required shutdown measures are larger than the associated Level A 
harassment zones, and those zones are relatively small (28.5 m at the 
largest during impact pile driving), we believe the PSO can effectively 
monitor the Level A harassment zones and therefore we do not anticipate 
any take by Level A harassment of harbor seals.

                     Table 11--Proposed Estimated Take by Level B Harassment of Harbor Seal
----------------------------------------------------------------------------------------------------------------
                                                      Density                                        Proposed
                     Source                          (animals/     Area  (km\2\)      Days of      Level B  take
                                                      km\2\)                         activity     by  harassment
----------------------------------------------------------------------------------------------------------------
Vibratory Installation and Removal 14-in H piles           3.957           2.190              12         103.999
Vibratory 36-in piles...........................           3.957          21.490               6         510.216
Impact 24-in piles..............................           3.957           0.004               6           0.095
                                                 ---------------------------------------------------------------
    Total Take by Level B harassment............  ..............  ..............  ..............          614.31
                                                                                                     (rounded to
                                                                                                            615)
----------------------------------------------------------------------------------------------------------------

California Sea Lions

    A predicted a density of 0.161 animals/km\2\ based for California 
sea lions was used to estimate take by Level B harassment (Table 12). 
The estimated take was calculated using this density multiplied by the 
area ensonified above the threshold multiplied by the number of days 
per activity (e.g., 6 days of impact pile driving) (Table 12). 
Therefore, a total of 25 instances of take by Level B harassment are 
proposed for California sea lions. The Level A harassment zones are all 
under 2.1 m for otariids; therefore, no take by Level A harassment of 
California sea lions is anticipated.

                 Table 12--Proposed Estimated Take by Level B Harassment of California Sea Lions
----------------------------------------------------------------------------------------------------------------
                                                      Density                                        Proposed
                     Source                          (animals/     Area  (km\2\)      Days of      Level B  take
                                                      km\2\)                         activity     by  harassment
----------------------------------------------------------------------------------------------------------------
Vibratory Installation and Removal 14-in H piles           0.161           2.190              12           4.231
Vibratory 36-in piles...........................           0.161          21.490               6          20.759
Impact 24-in piles..............................           0.161           0.004               6           0.004
                                                 ---------------------------------------------------------------
    Total Take by Level B harassment............  ..............  ..............  ..............          24.994
                                                                                                     (rounded to
                                                                                                             25)
----------------------------------------------------------------------------------------------------------------

Northern Elephant Seal

    There are no density estimates of northern elephant seals available 
in the project area. Elephant seals breed between December and March 
and have been rarely cited in San Francisco Bay. It is anticipated that 
if an elephant seal is encountered at all during pile driving or 
drilling it would be a juvenile. For the purpose of this assessment, we 
predict that up to one northern elephant seal may occur in the San 
Francisco Bay in the Project vicinity on up to 20 percent of pile 
driving days (i.e., up to 4.8 individuals in 24 days). This assumption 
is consistent with the recent IHA for the demolition and reuse of the 
marine foundations of the original east span of the San Francisco-
Oakland Bay Bridge (CALTRANS 2018). Therefore, NMFS proposes to 
authorize five takes (0.2 seals/day multiplied by 24 project days) by 
Level B harassment of elephant seals. Because the required shutdown 
measures are larger than the associated Level A harassment zones, and 
those zones are relatively small (28.5 m at the largest during impact 
pile driving), we believe the PSO can effectively monitor the Level A 
harassment zones and therefore we do not anticipate any take by Level A 
harassment of northern elephant seals.

Northern Fur Seals

    There are no density estimates of northern fur seals available in 
the project area. The Marine Mammal Center (TMMC) reported only two to 
four northern fur seal strandings in the Bay in 2015 and 2016 (in 
Marin, San Francisco, and Santa Clara counties) (TMMC 2017). To account 
for the possible rare presence of the species in the action area, NMFS 
proposes to authorize three takes by Level B harassment of northern fur 
seals. The Level A harassment zones are all under 2.1 m for otariids; 
therefore, no take by Level A harassment of Northern fur seals is 
anticipated.
    Table 13 below summarizes the proposed estimated take for all the 
species described above as a percentage of stock abundance.

                                          Table 13--Proposed Take Estimates as a Percentage of Stock Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Species                      Stock  (NEST)           Level A  harassment       Level B  harassment              Percent  of stock
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray Whale........................  Eastern North Pacific       0.......................  7.......................  Less than 1 percent.
                                     (26,960).

[[Page 34367]]

 
Bottlenose Dolphin................  California Coastal (453)..  0.......................  48......................  10.596 percent.
Harbor Porpoise...................  San Francisco-Russian       0.......................  27......................  Less than one percent.
                                     River (9,886).
Harbor Seal.......................  California (30,968).......  0.......................  615.....................  Less than 2 percent.
Northern Elephant Seal............  California Breeding         0.......................  5.......................  Less than one percent.
                                     (179,000).
California Sea Lion...............  U.S. (257,606)............  0.......................  25......................  Less than one percent.
Northern fur seal.................  Eastern DPS, California     0.......................  3.......................  Less than one percent.
                                     (20,000 ).
--------------------------------------------------------------------------------------------------------------------------------------------------------

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 such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such 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 such 
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, 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:

Timing Restrictions

    All work will be conducted during daylight hours. If poor 
environmental conditions restrict visibility full visibility of the 
shutdown zone, pile installation would be delayed.

Sound Attenuation

    To minimize noise during impact pile driving, a 12-inch thick wood 
cushion block will be used. Bubble curtains will be also used during 
any impact pile driving of piles located in the water. The bubble 
curtain will be operated in a manner consistent with the following 
performance standards:
    a. The bubble curtain will distribute air bubbles around 100 
percent of the piling perimeter for the full depth of the water column;
    b. The lowest bubble ring will be in contact with the mudline for 
the full circumference of the ring, and the weights attached to the 
bottom ring shall ensure 100 percent mudline contact. No parts of the 
ring or other objects shall prevent full mudline contact; and
    c. Air flow to the bubblers must be balanced around the 
circumference of the pile.

Soft Start

    Soft start requires contractors to provide an initial set of 
strikes at reduced energy, followed by a thirty-second waiting period, 
then two subsequent reduced energy strike sets. A soft start must 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.

Shutdown Zone for In-Water Heavy Machinery Work

    For in-water heavy machinery work other than pile driving, if a 
marine mammal comes within 10 m of such operations, operations shall 
cease and vessels shall reduce speed to the minimum level required to 
maintain steerage and safe working conditions.

Shutdown Zones

    For all pile driving/removal and drilling activities, the City will 
establish shutdown zones for a marine mammal species that is greater 
than its corresponding Level A harassment zone. The calculated PTS 
isopleths were rounded up to a whole number to determine the actual 
shutdown zones that the applicant will operate under (Table 14). 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).

                                                                 Table 14--Pile Driving Shutdown Zones During Project Activities
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Shutdown Zones (radial distance in meters, area in km \2\*)
              Activity              ------------------------------------------------------------------------------------------------------------------------------------------------------------
                                        Low-frequency cetaceans        Mid-frequency cetaceans        High-frequency cetaceans                Phocid                         Otariid
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                In-Water Construction Activities
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Heavy machinery work (other than     10 (0.00015 km\2\)...........  10 (0.00015 km\2\)...........  10 (0.00015 km\2\)...........  10 (0.00015 km\2\)...........  10 (0.00015 km\2\)
 pile driving).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                 Vibratory Pile Driving/Removal
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
14-in H pile steel installation/     10 (0.00015 km\2\............  10 (0.00015 km\2\............  10 (0.00015 km\2\............  10 (0.00015 km\2\............  10 (0.00015 km\2\
 removal.

[[Page 34368]]

 
36-in steel permanent installation.  15 (0.00035 km\2\)...........  10 (0.00015 km\2\)...........  20 (0.00063 km\2\)...........  10 (0.00015 km\2\)...........  10 (0.00015 km\2\)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                       Impact Pile Driving
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
24-in concrete permanent             55 (0.00475 km\2\)...........  10 (0.00015 km\2\)...........  65 (0.00663 km\2\)...........  30 (0.00141 km\2\)...........  10 (0.00015 km\2\)
 installation.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
* Note: km\2\ were divided by two to account for land.

Non-Authorized Take Prohibited

    If a species enters or approaches the Level B zone and that species 
is either not authorized for take or its authorized takes are met, pile 
driving and removal activities must shut down immediately using delay 
and shut-down procedures. Activities must not resume until the animal 
has been confirmed to have left the area or an observation time period 
of 15 minutes has elapsed for pinnipeds and small cetaceans and 30 
minutes for large whales.
    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 of 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, requirements pertaining to 
the monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
    [ssquf] Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    [ssquf] 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);
    [ssquf] Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    [ssquf] How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    [ssquf] Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    [ssquf] Mitigation and monitoring effectiveness.

Pre-Activity Monitoring

    Prior to the start of daily in-water construction activity, or 
whenever a break in pile driving of 30 min or longer occurs, PSOs will 
observe the shutdown and monitoring zones for a period of 30 min. The 
shutdown zone will be cleared when a marine mammal has not been 
observed within the zone for that 30-min period. If a marine mammal is 
observed within the shutdown zone, pile driving activities will not 
begin until the animal has left the shutdown zone or has not been 
observed for 15 min. If the Level B Harassment Monitoring Zone has been 
observed for 30 min and no marine mammals (for which take has not been 
authorized) are present within the zone, work can continue even if 
visibility becomes impaired within the Monitoring Zone. When a marine 
mammal permitted for Level B harassment take has been permitted is 
present in the Monitoring zone, piling activities may begin and Level B 
harassment take will be recorded.

Monitoring Zones

    The City will establish and observe monitoring zones for Level B 
harassment as presented in Table 9. The monitoring zones for this 
project are areas where SPLs are equal to or exceed 120 dB rms (for 
vibratory pile driving/removal) and 160 dB rms (for impact pile 
driving). These zones provide utility for monitoring conducted for 
mitigation purposes (i.e., shutdown zone monitoring) by establishing 
monitoring protocols for areas adjacent to the shutdown zones. 
Monitoring of the Level B harassment zones enables observers to be 
aware of and communicate the presence of marine mammals in the project 
area, but outside the shutdown zone, and thus prepare for potential 
shutdowns of activity.

Visual Monitoring

    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after all pile driving/removal and socking/rock anchoring 
activities. In addition, PSO 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/removed. Pile driving/removal activities include the time 
to install, remove a single pile or series of piles, as long as the 
time elapsed between uses of the pile driving equipment is no more than 
thirty minutes.
    Monitoring will be conducted by PSOs from on land. The number of 
PSOs will vary from one to two, depending on the type of pile driving, 
method of pile driving and size of pile, all of which determines the 
size of the harassment zones. Monitoring locations will be selected to 
provide an unobstructed view of all water within the shutdown zone and 
as much of the Level B harassment zone as possible for pile driving 
activities. A single monitor will be present during impact pile 
driving, when impacts of the project

[[Page 34369]]

will be limited to the area within the Alameda Lagoon, and two monitors 
will be present during vibratory pile driving when project impacts will 
extend into the waters of the San Francisco Bay.
    In addition, PSOs will work in shifts lasting no longer than 4 
hours with at least a 1-hour break between shifts, and will not perform 
duties as a PSO for more than 12 hours in a 24[hyphen]hour period (to 
reduce PSO fatigue).
    Monitoring of pile driving shall be conducted by qualified, NMFS-
approved PSOs, who shall have no other assigned tasks during monitoring 
periods. The City shall adhere to the following conditions when 
selecting PSOs:
    [ssquf] Independent PSOs shall be used (i.e., not construction 
personnel);
    [ssquf] At least one PSO must have prior experience working as a 
marine mammal observer during construction activities;
    [ssquf] Other PSOs may substitute education (degree in biological 
science or related field) or training for experience;
    [ssquf] Where a team of three or more PSOs are required, a lead 
observer or monitoring coordinator shall be designated. The lead 
observer must have prior experience working as a marine mammal observer 
during construction; and
    [ssquf] The City shall submit PSO CVs for approval by NMFS for all 
observers prior to monitoring.
    The City shall ensure that the PSOs have the following additional 
qualifications:
    [ssquf] Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
    [ssquf] Experience and ability to conduct field observations and 
collect data according to assigned protocols;
    [ssquf] Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    [ssquf] Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    [ssquf] 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;
    [ssquf] 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; and
    [ssquf] Sufficient training, orientation, or experience with the 
construction operations to provide for personal safety during 
observations.

Acoustic Monitoring

    The City has developed a sound attenuation monitoring plan to 
protect fish and marine mammals during pile driving activities (see 
Appendix B of the application for further details). The acoustic 
monitoring will include documentation of the following, at a minimum:
    [ssquf] Hydrophone equipment and methods: recording device, 
sampling rate, distance from the pile where recordings were made; and 
depth of recording device(s);
    [ssquf] Type of pile being driven and method of driving during 
recordings; and
    [ssquf] Mean, medium, and maximum sound levels (dB re: 1[micro]Pa): 
cumulative sound exposure level, peak sound pressure level, rms sound 
pressure level, and single-strike sound exposure level.

Reporting of Injured or Dead Marine Mammals

    In the unanticipated event that the planned activity clearly causes 
the take of a marine mammal in a manner prohibited by the IHA, such as 
serious injury, or mortality, the City must immediately cease the 
specified activities and report the incident to the NMFS Office of 
Protected Resources and the West Coast Region Stranding Coordinator. 
The report must include the following information:
    [ssquf] Time and date of the incident;
    [ssquf] Description of the incident;
    [ssquf] Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    [ssquf] Description of all marine mammal observations and active 
sound source use in the 24 hours preceding the incident;
    [ssquf] Species identification or description of the animal(s) 
involved;
    [ssquf] Fate of the animal(s); and
    [ssquf] Photographs or video footage of the animal(s).
    Activities must not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with the City to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. The City may not 
resume their activities until notified by NMFS.
    In the event the City discovers an injured or dead marine mammal, 
and the lead observer determines that the cause of the injury or death 
is unknown and the death is relatively recent (e.g., in less than a 
moderate state of decomposition), the City must immediately report the 
incident to the Office of Protected Resources, NMFS, and the West Coast 
Region Stranding Coordinator, NMFS. The report must include the same 
information as the bullets described above. Activities may continue 
while NMFS reviews the circumstances of the incident. NMFS will work 
with the City to determine whether additional mitigation measures or 
modifications to the activities are appropriate.
    In the event that the City discovers an injured or dead marine 
mammal, and the lead observer determines that the injury or death is 
not associated with or related to the specified activities (e.g., 
previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), the City must report the incident 
to the Office of Protected Resources, NMFS, and the West Coast Region 
Stranding Coordinator, NMFS, within 24 hours of the discovery.

Final Report

    The City shall submit a draft report to NMFS no later than 90 days 
following the end of construction activities or 60 days prior to the 
issuance of any subsequent IHA for the project. The City shall provide 
a final report within 30 days following resolution of NMFS' comments on 
the draft report. Reports shall contain, at minimum, the following:
    [ssquf] Date and time that monitored activity begins and ends for 
each day conducted (monitoring period);
    [ssquf] Construction activities occurring during each daily 
observation period, including how many and what type of piles driven;
    [ssquf] Deviation from initial proposal in pile numbers, pile 
types, average driving times, etc.;
    [ssquf] Weather parameters in each monitoring period (e.g., wind 
speed, percent cloud cover, visibility);
    [ssquf] Water conditions in each monitoring period (e.g., sea 
state, tide state);
    [ssquf] For each marine mammal sighting:
    [cir] Species, numbers, and, if possible, sex and age class of 
marine mammals;
    [cir] Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
    [cir] Type of construction activity that was taking place at the 
time of sighting;

[[Page 34370]]

    [cir] Location and distance from pile driving activities to marine 
mammals and distance from the marine mammals to the observation point;
    [cir] If shutdown was implemented, behavioral reactions noted and 
if they occurred before or after shutdown.
    [cir] Estimated amount of time that the animals remained in the 
Level A or B Harassment Zone.
    [ssquf] Description of implementation of mitigation measures within 
each monitoring period (e.g., shutdown or delay);
    [ssquf] Other human activity in the area within each monitoring 
period;
    [ssquf] A summary of the following:
    [cir] Total number of individuals of each species detected within 
the Level B Harassment Zone, and estimated as taken if correction 
factor appropriate;
    [cir] Total number of individuals of each species detected within 
the Level A Harassment Zone and the average amount of time that they 
remained in that zone; and
    [cir] Daily average number of individuals of each species 
(differentiated by month as appropriate) detected within the Level B 
Harassment Zone, and estimated as taken, if appropriate.

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).
    As stated in the proposed mitigation section, shutdown zones that 
are larger than the Level A harassment zones and are expected avoid the 
likelihood of Level A harassment for all seven species.
    Exposures to elevated sound levels produced during pile driving 
activities may cause behavioral disturbance of marine mammals, but they 
are expected to be mild and temporary. Effects on individuals that are 
taken by Level B harassment, on the basis of reports in the literature 
as well as monitoring from other similar activities, will likely be 
limited to reactions such as increased swimming speeds, increased 
surfacing time, or decreased foraging (if such activity were occurring) 
(e.g., Thorson and Reyff, 2006; Lerma, 2014). Most likely, individuals 
will simply move away from the sound source and be temporarily 
displaced from the areas of pile driving, although even this reaction 
has been observed primarily only in association with impact pile 
driving. These reactions and behavioral changes are expected to subside 
quickly when the exposures cease.
    To minimize noise during pile driving, and thereby both the scale 
and potential severity of the anticipated effects, the City will use 
pile cushions and a bubble curtain during impact pile driving.
    During all impact driving, implementation of soft start procedures 
and monitoring of established shutdown zones will be required, 
significantly reducing the possibility of injury. Given sufficient 
notice through use of soft start (for impact driving), marine mammals 
are expected to move away from an irritating sound source prior to it 
becoming potentially injurious. In addition, PSOs will be stationed 
within the action area whenever pile driving/removal activities are 
underway. Depending on the activity, the City will employ one to two 
PSOs to ensure all monitoring and shutdown zones are properly observed.
    Two known pinniped haul-out sites (non-pupping sites) are located 
in the vicinity of the project area. One is an existing haul out 
platform approximately 0.5 mi southeast of the project area (separated 
from project activities by approximately 0.3 mi of developed areas on-
land). The second haul out is the western end of Breakwater Island, 
approximately 1.0 mi southwest of the location of pile driving 
activities (Figure 4 of the application). They are both well outside 
the PTS isopleths for pinnipeds and no Level A harassment is expected. 
Exposures to elevated sound levels produced during pile driving 
activities once the animals enter the water from the haul outs may 
cause behavioral responses by an animal, but they are expected to be 
mild and temporary and limited to Level B harassment,
    The proposed activities would not result in permanent impacts to 
habitats used directly by marine mammals except the actual footprint of 
the project. The footprint of the project is small, and equal to the 
area the ferry associated pile placement. The installation of piles for 
the new pier will result in permanent impacts on 61 ft\2\ of aquatic 
habitat. At best, the impact area, which is located in Seaplane Lagoon, 
provides marginal foraging habitat for marine mammals and fish. In 
addition, impacts to marine mammal prey species are expected to be 
minor and temporary. Overall, the area impacted by the project is very 
small compared to the available habitat in the bay. The most likely 
impact to prey will be temporary behavioral avoidance of the immediate 
area. During pile driving/removal activities, it is expected that fish 
and marine mammals would temporarily move to nearby locations and 
return to the area following cessation of in-water construction 
activities. Therefore, indirect effects on marine mammal prey during 
the construction are not expected to be substantial.
    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:
    [ssquf] No serious injury or mortality is anticipated;
    [ssquf] No Level A Harassment is anticipated or proposed for 
authorization;
    [ssquf] Minimal impacts to marine mammal habitat are expected;
    [ssquf] The action area is located and within an active marine 
commercial area;
    [ssquf] There are no rookeries, or other known areas or features of 
special significance for foraging or reproduction in the project area;
    [ssquf] Anticipated incidents of Level B harassment consist of, at 
worst, temporary modifications in behavior; and
    [ssquf] The required mitigation measures (i.e. shutdown zones and 
pile cushion, and bubble curtain) are expected to be

[[Page 34371]]

effective in reducing the effects of the specified activity.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the 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. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities.
    The take of six marine mammal stocks proposed for authorization 
comprises less than two percent of the stock abundance, and less than 
11 percent for bottlenose dolphins (California coastal).
    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.

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. No ESA listed species are proposed for take. 
Therefore, NMFS has determined consultation under the ESA is not 
required.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the City for conducting for the proposed pile driving 
and removal activities for construction of the Alameda Seaplane Lagoon 
ferry terminal for one year, beginning August 2019, 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 pile 
driving and removal activities for construction of the ferry terminal. 
We also request comment on the potential for renewal of this proposed 
IHA as described in the paragraph below. Please include with your 
comments any supporting data or literature citations to help inform our 
final decision on the request for MMPA authorization.
    [ssquf] On a case-by-case basis, NMFS may issue a one-year IHA 
renewal with an additional 15 days for public comments when (1) another 
year of identical or nearly identical activities as described in the 
Specified Activities section of this notice is planned or (2) the 
activities as described in the Specified Activities section of this 
notice would not be completed by the time the IHA expires and a second 
IHA 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 expiration of the current IHA.
    [ssquf] The request for renewal must include the following:
    (1) An explanation that the activities to be conducted under the 
requested Renewal 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 
because only a subset of the initially analyzed activities remain to be 
completed under the Renewal); 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;
    [ssquf] 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: July 15, 2019.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2019-15299 Filed 7-17-19; 8:45 am]
 BILLING CODE 3510-22-P