Takes of Marine Mammals Incidental To Specified Activities; Taking Marine Mammals Incidental to the South Basin Improvements Project at the San Francisco Ferry Terminal, 18507-18533 [2018-08888]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 83, Number 82 (Friday, April 27, 2018)]
[Notices]
[Pages 18507-18533]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-08888]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG132


Takes of Marine Mammals Incidental To Specified Activities; 
Taking Marine Mammals Incidental to the South Basin Improvements 
Project at the San Francisco Ferry Terminal

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

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SUMMARY: NMFS has received a request from the San Francisco Bay Area 
Water Emergency Transportation Authority (WETA) for authorization to 
take marine mammals incidental to Downtown San Francisco Ferry Terminal 
Expansion Project, South Basin Improvements Project in San Francisco, 
California. Pursuant to the Marine Mammal Protection Act (MMPA), NMFS 
is requesting comments on its proposal to issue an incidental 
harassment authorization (IHA) to incidentally take marine mammals 
during the specified activities. NMFS 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 May 29, 
2018.

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-

[[Page 18508]]

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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities 
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: Amy Fowler, 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/national/marine-mammal-protection/incidental-take-authorizations-construction-activities. In case of problems 
accessing these documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

    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 
authorization is provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 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.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 
mammal.
    Except with respect to certain activities not pertinent here, 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).

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 January 22, 2018, NMFS received a request from WETA for an IHA 
to take marine mammals incidental to expansion and improvements at the 
downtown San Francisco ferry terminal. The application was determined 
to be adequate and complete on April 10, 2018. WETA's request is for 
take of seven species of marine mammals by Level B harassment only. 
This authorization would be valid from June 1, 2018 to May 31, 2019. 
Neither WETA nor NMFS expect serious injury or mortality to result from 
this activity and, therefore, an IHA is appropriate.
    NMFS previously issued an IHA to WETA for similar work (82 FR 
29521, June 29, 2017). WETA complied with all the requirements (e.g., 
mitigation, monitoring, and reporting) of the previous IHA and 
information regarding their monitoring results may be found in the 
``Estimated Take'' section.

Description of Proposed Activity

Overview

    WETA is proposing to expand berthing capacity at the Downtown San 
Francisco Ferry Terminal, located at the San Francisco Ferry Building, 
to support existing and future planned water transit services operated 
on San Francisco Bay by WETA and WETA's emergency operations.
    The Downtown San Francisco Ferry Terminal Expansion Project would 
eventually include phased construction of three new water transit gates 
and overwater berthing facilities, in addition to supportive landside 
improvements, such as additional passenger waiting and queueing areas, 
circulation improvements, and other water transit-related amenities. 
The new gates and other improvements would be designed to accommodate 
future planned water transit services between Downtown San Francisco 
and Antioch, Berkeley, Martinez, Hercules, Redwood City, Richmond, and 
Treasure Island, as well as emergency operation needs. According to 
current planning and operating assumptions, WETA will not require all 
three new gates (Gates A, F, and G) to support existing and new 
services immediately. As a result, WETA is planning that project 
construction will be phased. The first phase will include construction 
of Gates F and G, as well as other related improvements in the South 
Basin.

Dates and Duration

    In-water construction activities (i.e., pile driving) will be 
scheduled to be completed during the authorized work window for 
construction in San Francisco Bay established by the Long-Term 
Management Strategy. In the project area, the authorized in-water work 
window is June 1 through November 30. WETA estimates the project may 
take up to 41 days of activity within the in-water work window. This 
proposed authorization would be valid from June 1, 2018 through May 31, 
2019.

Specific Geographic Region

    The San Francisco ferry terminal is located in the western shore of 
San Francisco Bay (see Figure 1 of WETA's application). The ferry 
terminal is five blocks north of the San Francisco-Oakland Bay Bridge 
(Bay Bridge). More

[[Page 18509]]

specifically, the South Basin of the terminal is located between Pier 
14 and the ferry plaza. San Francisco Bay and the adjacent Sacramento-
San Joaquin Delta make up one of the largest estuarine systems on the 
continent. The Bay has undergone extensive industrialization, but 
remains an important environment for healthy marine mammal populations 
year round. The area surrounding the proposed activity is an intertidal 
landscape with heavy industrial use and boat traffic.

Detailed Description of Specific Activity

    The project supports existing and future planned water transit 
services operated by WETA and regional policies to encourage transit 
uses. Furthermore, the project addresses deficiencies in the 
transportation network that impede water transit operation, passenger 
access, and passenger circulation at the Ferry Terminal.
    The project will accommodate the existing and future planned water 
transit service outlined in WETA's Implementation and Operations Plan 
for the San Francisco Bay Area. The addition of two new gates will 
accommodate an expansion of WETA services from 5,100 to 19,160 
passengers per weekday by the year 2035; and an increase in peak-period 
WETA vessel arrivals from 14 to approximately 30. In addition to 
regularly scheduled ferry transit, facility improvements would allow 
for increased capacity for emergency use. With the improvements in 
place, WETA will have the capacity to evacuate approximately 7,200 
passengers per hour from its four gates.
    The new gates (Gates F and G) will be built similarly. Each gate 
will be designed with an entrance portal--a prominent doorway providing 
passenger information and physically separating the berthing structures 
from the surrounding area. The entrance portal will also contain doors, 
which can be secured.
    Berthing structures will be provided for each new gate, consisting 
of floats, gangways, and guide piles. Figure 3 of WETA's application 
depicts a simulated view of the proposed berthing structures. The steel 
floats will be approximately 42 feet (ft) wide by 135 ft long. The 
steel truss gangways will be approximately 14 ft wide and 105 ft long. 
The gangway will be designed to rise and fall with tidal variations 
while meeting Americans with Disabilities Act (ADA) requirements. The 
gangway and the float will be designed with canopies, consistent with 
the current design of Gates B and E. The berthing structures will be 
fabricated offsite and floated to the project area by barge.
    Six steel guide piles will be required to secure each float in 
place. In addition, dolphin piles may be used at each berthing 
structure to protect against the collision of vessels with other 
structures or vessels. A total of up to 14 dolphin piles may be 
installed, consisting of ten new dolphin piles and four relocated 
dolphin piles.
    Chock-block fendering will be added along the East Bayside 
Promenade, to adjacent structures to prevent collision. The chock-block 
fendering will consist of square, 12-inch-wide, polyurethane-coated, 
pressure-treated wood blocks that are connected along the side of the 
adjacent pier structure, and supported by polyurethane-coated, 
pressure-treated wood piles.
    In addition, the existing Gate E float will be moved 43 ft to the 
east, to align with the new gates and the East Bayside Promenade. The 
existing six 36-inch (in) diameter steel guide piles will be removed 
using vibratory extraction, and reinstalled to secure the Gate E float 
in place. Because of Gate E's new location, to meet ADA requirements, 
the existing 90 ft steel truss gangway will be replaced with a longer, 
105 ft gangway.

                                      Table 1--Summary of Pile Installation
----------------------------------------------------------------------------------------------------------------
                                  Pile diameter
        Project element               (in)          Pile length (ft)      Number of piles      Schedule (days)
----------------------------------------------------------------------------------------------------------------
Embarcadero Plaza, East Bayside              30  135 to 155...........  18................  Up to 9.
 Promenade, and Interim Access
 Structure.
Embarcadero Plaza, East Bayside              24  135 to 155...........  30................  Up to 15.
 Promenade, and Interim Access
 Structure.
Gates E, F, and G Dolphin Piles              36  145 to 155...........  10 (two at each of  Up to 5.
                                                                         the floats for
                                                                         protection, two
                                                                         between each of
                                                                         the floats).
Gate F and G Guide Piles.......              36  140 to 150...........  12 (six per gate).  Up to 6.
Gate E Guide Piles.............              36  145 to 155...........  6.................  Up to 3.
Barrier Piles near Pier 14.....              24  135 to 155...........  5.................  Up to 3.
    Total......................  ..............  .....................  81 piles..........  41.
----------------------------------------------------------------------------------------------------------------

    Construction of the project improvements requires pile driving. 
Pile driving for the project includes impact or vibratory pile driving 
associated with construction of the berthing structures, the 
Embarcadero Plaza, and East Bayside Promenade. Much of the pile driving 
associated with the project was completed in 2017 and was covered under 
a previous IHA. All pile driving completed in 2017 was vibratory; no 
impact pile driving was conducted. The pile sizes and numbers that will 
be driven in 2018 are detailed in Table 1. Pile driving will occur 
during daylight hours only and one hammer will be used at a time. 
Vibratory driving may install up to four piles per day and impact 
driving may install up to three piles per day but a conservative 
estimate of two piles per day is used to estimate the duration of the 
project. Vibratory driving of 24-in and 30-in piles may take up to 15 
minutes per pile while vibratory driving of 36-in piles may take up to 
20 minutes per pile. Piles driven with an impact hammer will require an 
estimated 1800 strikes per pile, regardless of pile size. Underwater 
sound and acoustic pressure resulting from pile driving could affect 
marine mammals by causing behavioral avoidance of the construction 
area, and/or injury to sensitive species.
    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 4 and 5 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 (SAR;

[[Page 18510]]

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 (www.fisheries.noaa.gov/find-species).
    Table 2 lists all species with expected potential for occurrence 
near downtown San Francisco 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. 2016 SARs (Caretta et al., 2017). All values presented in 
Table 2 are the most recent available at the time of publication and 
are available in the 2016 SARs (Caretta et al., 2017).

                                            Table 2--Marine Mammals in the Vicinity of Downtown San Francisco
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             Stock abundance (CV,
            Common name                  Scientific name              Stock             ESA/MMPA status;       Nmin, most recent       PBR     Annual M/
                                                                                      strategic (Y/N) \1\    abundance survey) \2\               SI \3\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Family Eschrichtiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray whale.........................  Eschrichtius robustus.  Eastern North Pacific.  -/-; N                 20,990 (0.05, 20,125,         624        132
                                                                                                             2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Family Balaenopteridae (rorquals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Humpback whale.....................  Megaptera novaeangliae  California/Oregon/      E/D; Y                 1,918 (0.03, 1,876,            11       >6.5
                                                              Washington.                                    2014).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin.................  Tursiops truncatus....  California Coastal....  -/-; N                 453 (0.06, 346, 2011).        2.7         >2
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocoenidae (porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor porpoise....................  Phocoena phocoena.....  San Francisco-Russian   -/-; N                 9,886 (0.51, 6,625,            66          0
                                                              River.                                         2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion................  Zalophus californianus  U.S...................  -/-; N                 296,750 (n/a, 153,337,      9,200        389
                                                                                                             2011).
Northern fur seal..................  Callorhinus ursinus...  California............  -/-; N                 14,050 (n/a, 7,524,           451        1.8
                                                                                                             2013).
Guadalupe fur seal.................  Arctocephalus           Mexico to California..  T/D; Y                 20,000 (n/a, 15,830,          542       >3.2
                                      townsendi.                                                             2010).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific harbor seal................  Phoca vitulina          California............  -/-; N                 30,968 (n/a, 27,348,        1,641         43
                                      richardii.                                                             2012).
Northern elephant seal.............  Mirounga                California Breeding...  -/-; N                 179,000 (n/a, 81,368,       4,882        8.8
                                      angustirostris.                                                        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.
\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.


[[Page 18511]]

    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 are rare 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). The Golden Gate is 
outside of this project's action area and humpback whales are not 
expected to be present during the project. 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 haulouts 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 
2017c). In the rare event that a Guadalupe fur seal is detected within 
the Level A or Level B harassment zones, work will cease until the 
animal has left the area (see ``Proposed Mitigation'').

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, 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. With the exception of an unusual mortality event in 
1999 and 2000, the population of Eastern North Pacific stock has 
increased over the last 20 years and has been stable since the 1990s 
(NMFS 2015c).
    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 2015c). 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 Biological 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. Some gray whales summer along the west coast 
of North America to forage and are additionally defined as the Pacific 
Coast Feeding Group. This group is separately monitored between June 1 
and November 1 between northern California and northern British 
Columbia by the International Whaling Commission (IWC 2012; 
Calambokidis et al., 2015). The Pacific Coast Feeding Group has 
increased in abundance estimates since the 1990s and has been stable 
since 2003 (Calambokidis et al., 2014).

Bottlenose Dolphin

    Since the 1982-83 El Ni[ntilde]o, which increased water 
temperatures off California, bottlenose dolphins have been consistently 
sighted along the central California coast (NMFS 2017b). The northern 
limit of their regular range is currently the Pacific coast off San 
Francisco and Marin Country and they occasionally enter San Francisco 
Bay, sometimes foraging for fish in Fort Point Cove, just inside the 
Golden Gate Bridge. The California Coastal Stock is frequently seen in 
nearshore waters (NMFS 2017b). 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 porpoises generally occur in groups of two to five 
individuals and are considered to be shy, relatively nonsocial animals. 
The harbor porpoise has a small body, with a short beak and medium-
sized dorsal fin. They can grow to approximately 5 ft and 170 pounds. 
Distribution of harbor porpoises is discontinuous due to a habitat 
preference of continental shelf waters. Harbor porpoises are typically 
found in waters less than 250 ft deep along the coast and in bays, 
estuaries, and harbors. Their prey consists of demersal and benthic 
species, such as schooling fish and cephalopods (NMFS 2014).

California Sea Lion

    California sea lions are sexually dimorphic eared seals (family 
Otariidae). Males can reach up to 8 ft long and weigh 700 pounds 
whereas females are smaller, approximately 6 ft long and 200 pounds. 
California sea lions breed in southern California and along the Channel 
Islands during the spring. Although most females remain in southern 
California waters year-round, males and some subadult females range 
widely and occupy protected embayments like San Francisco Bay 
throughout the year (Caltrans 2012). Pupping does not occur in San 
Francisco Bay. They are extremely intelligent and social, and spend 
much of their time aggregated at communal haulouts. Group hunting is 
common and they may cooperate with other species, such as dolphins, 
when hunting large schools of fish. California sea lions feed on a 
variety of fish and squid species (NMFS 2015b).
    During El Ni[ntilde]o events, there is an increase in pup and 
juvenile mortality, which in turn affects future age and sex classes. 
Additionally, because there are fewer females present in the population 
after such events, pup production is further limited. Declines in pup 
production observed in 2000 and 2003 can be attributed in part to 
previous El Ni[ntilde]o events, which affected the number of 
reproductive females in the population, and in part to domoic poisoning 
and an infestation of hook worms, which caused an increase in pup 
mortality (NMFS 2017a). There was an unusual mortality event declared 
in 2013 due to a high number of strandings with reasons unknown, but 
hypothesized to be associated with low forage fish availability close 
to pupping areas (NMFS 2015b). Despite intermittent years of increased 
pup mortality, statistical analyses of pup counts between 1975 and 2011 
determined an approximate 5.4 percent annual increase between 1975 and 
2008 (NMFS 2017a).
    Although there is little information regarding the foraging 
behavior of the California sea lion in the 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 2001). 
California sea lions in the San Francisco Bay may be feeding on Pacific 
herring (Clupea harengus pallasii), northern

[[Page 18512]]

anchovy (Engraulis mordax), or other prey species (Caltrans 2013).

Northern Fur Seal

    The range of the northern fur seal extends from southern 
California, north to the Bering Sea and west to the Okhotsk Sea and 
Honshu Island, Japan (NMFS 2015e). There are two stocks of northern fur 
seal, the California stock and the Eastern Pacific stock. The Eastern 
Pacific stock is listed as strategic and depleted under the MMPA but 
the California stock is not (NMFS 2015e). Both the Eastern Pacific and 
California stocks forage in offshore waters outside San Francisco Bay. 
During the breeding season, the majority of the worldwide population is 
found on the Pribilof Islands in the Southern Bering Sea, with the 
remaining animals spread throughout the North Pacific Ocean. On the 
coast of California, small breeding colonies are present at San Miguel 
Island off southern California and the Farallon Islands off central 
California (NMFS 2015e). Northern fur seals are a pelagic species and 
are rarely seen near the shore away from breeding areas.

Harbor Seal

    The Pacific harbor seal is one of five subspecies of Phoca 
vitulina, or the common harbor seal. They are a true seal, with a 
rounded head and visible ear canal. Males and females are similar in 
size and can exceed 6 ft and 300 pounds. Harbor seals generally do not 
migrate annually. They display year-round site fidelity, although they 
have been known to swim several hundred miles to find food or suitable 
breeding habitat.
    Harbor seals have the broadest range of any pinniped, inhabiting 
both the Atlantic and Pacific oceans. In the Pacific, they are found in 
nearshore coastal and estuarine habitats form Baja California to 
Alaska, and from Russia to Japan. Of the three recognized populations 
of harbor seals along the west coast of the continental U.S., the 
California stock occurs in California coastal waters.
    Harbor seals forage in shallow waters on a variety of fish and 
crustaceans that are present throughout San Francisco Bay, and 
therefore could occasionally be found foraging in the action area. They 
are opportunistic, general foragers (Gibble 2011). In San Francisco 
Bay, harbor seals forage in shallow, intertidal waters on a variety of 
fish, crustaceans, and a few cephalopods. The most numerous prey items 
identified in harbor seal fecal samples from haulouts in San Francisco 
Bay include yellow fin goby (Acanthogobius flavimanus), northern 
anchovy, Pacific herring, staghorn sculpin (Leptocottus armatus), 
plainfin midshipman (Porichthys notatus), and white croaker (Genyonemus 
lineatas) (Harvey and Torok 1994).
    Although solitary in the water, harbor seals come ashore at 
haulouts to rest, socialize, breed, nurse, molt, and thermoregulate. 
Habitats used as haulout sites include tidal rocks, bayflats, sandbars, 
and sandy beaches (Zeiner et al., 1990). Haulout sites are relatively 
consistent from year to year (Kopec and Harvey 1995) and females have 
been recorded returning to their own natal haulout 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 is the closest haulout to the project, 
located approximately 1.5 miles from the project location. Harbor seals 
use Yerba Buena Island year-round, with the largest numbers seen during 
winter months, when Pacific herring spawn (Grigg 2008). During marine 
mammal monitoring for construction of the new Bay Bridge, harbor seal 
counts at Yerba Buena Island ranged from zero to a maximum of 188 
individuals (Caltrans 2012). Higher numbers may occur during molting 
and breeding seasons.

Northern Elephant Seal

    Northern elephant seals are common on California coastal mainland 
and island sites where they pup, breed, rest, and molt. The largest 
rookeries are on San Nicolas and San Miguel Islands in the Northern 
Channel Islands. In the vicinity of San Francisco, elephant seals 
breed, molt, and haul out at A[ntilde]o Nuevo Island, the Farallon 
Islands, and Point Reyes National Seashore (Lowry et al., 2014). Both 
sexes make two foraging migrations each year, one after breeding and 
the second after molting (Stewart and DeLong 1995). Adults reside in 
offshore pelagic waters when not breeding or molting. Northern elephant 
seals haul out to give birth and breed from December through March, and 
pups remain onshore or in adjacent shallow water through May, when they 
may occasionally make brief stops in San Francisco Bay (Caltrans 
2015b).

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 (2016) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibels (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. The functional groups and 
the associated frequencies are indicated below (note that these 
frequency ranges correspond to the range for the composite group, with 
the entire range not necessarily reflecting the capabilities of every 
species within that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 hertz (Hz) and 35 
kilohertz (kHz);
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz;
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 Hz to 86 kHz; 
and
     Pinnipeds in water; Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz.
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating

[[Page 18513]]

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 (2016) for a review of available information. 
Seven marine mammal species (three cetacean and four pinniped (two 
otariid and two phocid) species) have the reasonable potential to co-
occur with the proposed survey activities. Please refer to Table 2. Of 
the cetacean species that may be present, one is classified as a low-
frequency cetacean (gray whale), one is classified as a mid-frequency 
cetacean (bottlenose dolphin), and one is classified as a high-
frequency cetacean (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.

Description of Sound Sources

    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 Hz or cycles per second. Wavelength is the distance 
between two peaks of a sound wave; lower frequency sounds have longer 
wavelengths than higher frequency sounds and attenuate (decrease) more 
rapidly in shallower water. Amplitude is the height of the sound 
pressure wave or the `loudness' of a sound and is typically measured 
using the dB scale. A dB is the ratio between a measured pressure (with 
sound) and a reference pressure (sound at a constant pressure, 
established by scientific standards). It is a logarithmic unit that 
accounts for large variations in amplitude; therefore, relatively small 
changes in dB ratings correspond to large changes in sound pressure. 
When referring to sound pressure levels (SPLs; the sound force per unit 
area), sound is referenced in the context of underwater sound pressure 
to 1 microPascal ([mu]Pa). One pascal is the pressure resulting from a 
force of one newton exerted over an area of one square meter. The 
source level (SL) represents the sound level at a distance of 1 m from 
the source (referenced to 1 [mu]Pa). The received level is the sound 
level at the listener's position. Note that all underwater sound levels 
in this document are referenced to a pressure of 1 [micro]Pa and all 
airborne sound levels in this document are referenced to a pressure of 
20 [micro]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.
    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 all 
directions away from the source (similar to ripples on the surface of a 
pond), except in cases where the source is directional. 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. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al., 1995), and 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., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction). A number of 
sources contribute to ambient sound, including the following 
(Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson 1995). In general, ambient sound levels tend to increase 
with increasing wind speed and wave height. Surf noise becomes 
important near shore, with measurements collected at a distance of 8.5 
km from shore showing an increase of 10 dB in the 100 to 700 Hz band 
during heavy surf conditions;
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times;
     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz; and
     Anthropogenic: Sources of ambient noise related to human 
activity include transportation (surface vessels and aircraft), 
dredging and construction, oil and gas drilling and production, seismic 
surveys, sonar, explosions, and ocean acoustic studies. Shipping noise 
typically dominates the total ambient noise 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 (Richardson et al., 1995). Sound from identifiable 
anthropogenic sources other than the activity of interest (e.g., a 
passing vessel) is sometimes termed background sound, as opposed to 
ambient sound.
    The sum of the various natural and anthropogenic sound sources at 
any given location and time--which comprise ``ambient'' or 
``background'' sound--depends not only on the SLs (as determined by 
current weather conditions and levels of biological and shipping 
activity) but also on the ability of sound to propagate through the 
environment. In turn, sound propagation is dependent on the spatially 
and temporally varying properties of the water column and sea floor, 
and is frequency-dependent. As a result of the dependence on a large 
number of varying factors, ambient sound levels can be expected to vary 
widely over both coarse and fine spatial and temporal scales. Sound 
levels at a given frequency and location can vary

[[Page 18514]]

by 10-20 dB from day to day (Richardson et al., 1995). The result is 
that, depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.
    The underwater acoustic environment at the ferry terminal is likely 
to be dominated by noise from day-to-day port and vessel activities. 
This is a highly industrialized area with high-use from small- to 
medium-sized vessels, and larger vessel that use the nearby major 
shipping channel. Underwater sound levels for water transit vessels, 
which operate throughout the day from the San Francisco Ferry Building 
ranged from 152 dB to 177 dB (WETA 2003a). While there are no current 
measurements of ambient noise levels at the ferry terminal, it is 
likely that levels within the basin periodically exceed the 120 dB 
threshold and, therefore, that the high levels of anthropogenic 
activity in the basin create an environment far different from quieter 
habitats where behavioral reactions to sounds around the 120 dB 
threshold have been observed (e.g., Malme et al., 1984, 1988).
    In-water construction activities associated with this project would 
include impact and vibratory pile driving. The sounds produced by these 
activities fall into one of two general sound types: Pulsed and non-
pulsed (defined in the following section). 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.
    Pulsed sound sources (e.g., 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; Harris 1998; NIOSH 1998; ISO 2003; ANSI 2005) 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 non-continuous (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 (such as 
those used by the U.S. Navy). The duration of such sounds, as received 
at a distance, can be greatly extended in a highly reverberant 
environment.
    Impact hammers operate by repeatedly dropping a heavy piston onto a 
pile to drive the pile into the substrate. Sound generated by impact 
hammers is characterized by rapid rise times and high peak levels, a 
potentially injurious combination (Hastings and Popper 2005). Vibratory 
hammers install piles by vibrating them and allowing the weight of the 
hammer to push them into the sediment. Vibratory hammers produce 
significantly less sound than impact hammers. Peak SPLs may be 180 dB 
or greater, but are generally 10 to 20 dB lower than SPLs generated 
during impact pile driving of the same-sized pile (Oestman et al., 
2009). Rise time is slower, reducing the probability and severity of 
injury, and sound energy is distributed over a greater amount of time 
(Nedwell and Edwards 2002; Carlson et al., 2005).

Acoustic Impacts

    Please refer to the information given previously (Description of 
Sound Sources) regarding sound, characteristics of sound types, and 
metrics used in this document. 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; Gotz 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 WETA's construction 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 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., permanent hearing 
impairment, certain non-auditory physical or physiological effects) 
only briefly as we do not expect that there is a reasonable likelihood 
that WETA's activities may result in such effects (see below for 
further discussion). 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 (Kastak et al., 1999; Schlundt et al., 2000; 
Finneran et al., 2002, 2005b). 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

[[Page 18515]]

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--PTS data exists only for a single harbor seal 
(Kastak et al., 2008)--but are assumed to be similar to those in humans 
and other terrestrial mammals. PTS typically occurs at exposure levels 
at least several dB above a 40-dB threshold shift approximates PTS 
onset; e.g., Kryter et al., 1966; Miller 1974) that inducing mild TTS 
(a 6-dB TS 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.
    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). WETA's activities do not 
involve the use of devices such as explosives or mid-frequency active 
sonar that are associated with these types of effects.
    Temporary threshold shift--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, 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 
(e.g., Finneran et al., 2002; Nachtigall et al., 2004; Kastak et al., 
2005; Lucke et al., 2009; Popov et al., 2011). In general, harbor seals 
(Kastak et al., 2005; Kastelein et al., 2012a) and harbor porpoises 
(Lucke et al., 2009; Kastelein et al., 2012b) have a lower TTS onset 
than other measured pinniped or cetacean species. 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) and Finneran and Jenkins (2012).
    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 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 seismic airguns or acoustic 
harassment devices) have been varied but often consist of avoidance 
behavior or other behavioral changes suggesting discomfort (Morton and 
Symonds 2002; see also Richardson et al., 1995; Nowacek et al., 2007).
    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,

[[Page 18516]]

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,b). 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, 2005b, 2006; Gailey et 
al., 2007).
    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., 2007b). 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 seismic 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 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;

[[Page 18517]]

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). 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 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., 2007b; 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.

Acoustic Effects, Underwater

    Potential Effects of Pile Driving--The effects of sounds from pile 
driving might include one or more of the following: temporary or 
permanent hearing impairment, non-auditory physical or physiological 
effects, behavioral disturbance, and masking (Richardson et al., 1995; 
Gordon et al., 2003; Nowacek et al., 2007; Southall et al., 2007). The 
effects of pile driving on marine mammals are dependent on several 
factors, including the type and depth of the animal; the pile size and 
type, and the intensity and duration of the pile driving sound; the 
substrate; the standoff distance between the pile and the animal; and 
the sound propagation properties of the environment. Impacts to marine 
mammals from pile driving activities are expected to result primarily 
from acoustic pathways. As such, the degree of effect is intrinsically 
related to the frequency, received level, and duration of the sound 
exposure, which are in turn influenced by the distance between the 
animal and the source. The further away from the source, the less 
intense the exposure

[[Page 18518]]

should be. The substrate and depth of the habitat affect the sound 
propagation properties of the environment. In addition, substrates that 
are soft (e.g., sand) would absorb or attenuate the sound more readily 
than hard substrates (e.g., rock) which may reflect the acoustic wave. 
Soft porous substrates would also likely require less time to drive the 
pile, and possibly less forceful equipment, which would ultimately 
decrease the intensity of the acoustic source.
    In the absence of mitigation, impacts to marine species could be 
expected to include physiological and behavioral responses to the 
acoustic signature (Viada et al., 2008). Potential effects from 
impulsive sound sources like pile driving can range in severity from 
effects such as behavioral disturbance to temporary or permanent 
hearing impairment (Yelverton et al., 1973).
    Hearing Impairment and Other Physical Effects-- Marine mammals 
exposed to high intensity sound repeatedly or for prolonged periods can 
experience hearing TSs. PTS constitutes injury, but TTS does not 
(Southall et al., 2007). Based on the best scientific information 
available, the SPLs for the construction activities in this project are 
below the thresholds that could cause TTS or the onset of PTS (Table 
3).
    Non-auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance effects, and other types of organ 
or tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited. In general, little is known about 
the potential for pile driving or removal to cause auditory impairment 
or other physical effects in marine mammals. Available data suggest 
that such effects, if they occur at all, would presumably be limited to 
short distances from the sound source and to activities that extend 
over a prolonged period. The available data do not allow identification 
of a specific exposure level above which non-auditory effects can be 
expected (Southall et al., 2007) or any meaningful quantitative 
predictions of the numbers (if any) of marine mammals that might be 
affected in those ways. Marine mammals that show behavioral avoidance 
of pile driving, including some odontocetes and some pinnipeds, are 
especially unlikely to incur auditory impairment or non-auditory 
physical effects.

Disturbance Reactions

    Responses to continuous sound, such as vibratory pile installation, 
have not been documented as well as responses to pulsed sounds. With 
both types of pile driving, it is likely that the onset of pile driving 
could result in temporary, short term changes in an animal's typical 
behavior 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 (e.g., pinnipeds flushing into water from haulouts 
or rookeries). Pinnipeds may increase their haul out time, possibly to 
avoid in-water disturbance (Thorson and Reyff 2006). If a marine mammal 
responds to a stimulus by changing its behavior (e.g., through 
relatively minor changes in locomotion direction/speed or vocalization 
behavior), the response may or may not constitute taking at the 
individual level, and is unlikely to affect the stock or the species as 
a whole. However, if a sound source displaces marine mammals from an 
important feeding or breeding area for a prolonged period, impacts on 
animals, and if so potentially on the stock or species, could 
potentially be significant (e.g., Lusseau and Bejder 2007; Weilgart 
2007).
    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 potentially lead to effects on 
growth, survival, or reproduction include:
     Drastic changes in diving/surfacing patterns (such as 
those thought to cause beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Longer-term habitat abandonment due to loss of desirable 
acoustic environment; and
     Longer-term cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic sound 
depends on both external factors (characteristics of sound sources and 
their paths) and the specific characteristics of the receiving animals 
(hearing, motivation, experience, demography) and is difficult to 
predict (Southall et al., 2007).

Auditory Masking

    Natural and artificial sounds can disrupt behavior by masking. The 
frequency range of the potentially masking sound is important in 
determining any potential behavioral impacts. Because sound generated 
from in-water pile driving and removal is mostly concentrated at low 
frequency ranges, it may have less effect on high frequency 
echolocation sounds made by porpoises. The most intense underwater 
sounds in the proposed action are those produced by impact pile 
driving. Given that the energy distribution of pile driving covers a 
broad frequency spectrum, sound from these sources would likely be 
within the audible range of marine mammals present in the project area. 
Impact pile driving activity is relatively short-term, with rapid 
pulses occurring for approximately fifteen minutes per pile. The 
probability for impact pile driving resulting from this proposed action 
masking acoustic signals important to the behavior and survival of 
marine mammal species is low. Vibratory pile driving is also relatively 
short-term, with rapid oscillations occurring for approximately one and 
a half hours per pile. It is possible that vibratory pile driving 
resulting from this proposed action may mask acoustic signals important 
to the behavior and survival of marine mammal species, but the short-
term duration and limited affected area would result in insignificant 
impacts from masking. 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.

Acoustic Effects, Airborne

    Pinnipeds that occur near the project site could be exposed to 
airborne sounds associated with pile driving and removal that have the 
potential to cause behavioral harassment, depending on their distance 
from pile driving activities. Cetaceans are not expected to be exposed 
to airborne sounds that would result in harassment as defined under the 
MMPA.
    Airborne noise will primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria. We

[[Page 18519]]

recognize that pinnipeds in the water could be exposed to airborne 
sound that may result in behavioral harassment when looking with heads 
above water. Most likely, airborne sound would cause behavioral 
responses similar to those discussed above in relation to underwater 
sound. For instance, anthropogenic sound could cause hauled-out 
pinnipeds to exhibit changes in their normal behavior, such as 
reduction in vocalizations, or cause them to temporarily abandon the 
area and move further from the source. However, these animals would 
previously have been `taken' as a result of exposure to underwater 
sound above the behavioral harassment thresholds, which are in all 
cases larger than those associated with airborne sound. Thus, the 
behavioral harassment of these animals is already accounted for in 
these estimates of potential take. Multiple instances of exposure to 
sound above NMFS' thresholds for behavioral harassment are not believed 
to result in increased behavioral disturbance, in either nature or 
intensity of disturbance reaction. Therefore, we do not believe that 
authorization of incidental take resulting from airborne sound for 
pinnipeds is warranted, and airborne sound is not discussed further 
here.

Anticipated Effects on Habitat

    The proposed activities at the Ferry Terminal would not result in 
permanent negative impacts to habitats used directly by marine mammals, 
but may have potential short-term impacts to food sources such as 
forage fish and may affect acoustic habitat (see masking discussion 
above). There are no known foraging hotspots or other ocean bottom 
structure of significant biological importance to marine mammals 
present in the marine waters of the project area. 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 in this document. The primary 
potential acoustic impacts to marine mammal habitat are associated with 
elevated sound levels produced by vibratory and impact pile driving and 
removal in the area. However, other potential impacts to the 
surrounding habitat from physical disturbance (i.e., increased 
turbidity) are also possible.

Pile Driving Effects on Potential Prey (Fish)

    Construction activities would produce continuous (i.e., vibratory 
pile driving) sounds and pulsed (i.e. impact driving) sounds. Fish 
react to sounds that are especially strong and/or intermittent low-
frequency sounds. Short duration, sharp sounds can cause overt or 
subtle changes in fish behavior and local distribution. 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). Sound 
pulses at received levels of 160 dB may cause subtle changes in fish 
behavior. SPLs of 180 dB may cause noticeable changes in behavior 
(Pearson et al., 1992; Skalski et al., 1992). SPLs of sufficient 
strength have been known to cause injury to fish and fish mortality.
    The most likely impact to fish from pile driving activities at the 
project area would be temporary behavioral avoidance of the area. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. In general, impacts to marine mammal prey 
species are expected to be minor and temporary due to the short 
timeframe for the project.

Pile Driving Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in San Francisco Bay. Avoidance by 
potential prey (i.e., fish) of the immediate area due to the temporary 
loss of this foraging habitat is also possible. The duration of fish 
avoidance of this area after pile driving stops is unknown, but a rapid 
return to normal recruitment, distribution and behavior is anticipated. 
Any behavioral avoidance by fish of the disturbed area would still 
leave significantly large areas of fish and marine mammal foraging 
habitat in the San Francisco ferry terminal and nearby vicinity in San 
Francisco Bay.
    The duration of the construction activities is relatively short. 
The construction window is six months long, with construction expected 
to take no more than 41 days. Each day, construction would only occur 
for a few hours during the day. Impacts to habitat and prey are 
expected to be minimal based on the short duration of activities.
    In summary, given the short daily duration of sound associated with 
individual pile driving events and the relatively small areas being 
affected, pile driving activities associated with the proposed action 
are not likely to have a permanent, adverse effect on any fish habitat, 
or populations of fish species. Thus, any impacts to marine mammal 
habitat are not expected to cause significant or long-term consequences 
for individual marine mammals or their populations.

Estimated Take

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of ``small numbers'' and the negligible impact 
determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as: any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would be by Level B harassment only, in the form 
of disruption of behavioral patterns for individual marine mammals 
resulting from exposure to acoustic sources (i.e., impact and vibratory 
pile driving). Based on the nature of the activity and the anticipated 
effectiveness of the mitigation measures (i.e., bubble curtain, soft 
start, shutdowns, etc.--discussed in detail below in Proposed 
Mitigation section), Level A harassment is neither anticipated nor 
proposed to be authorized. As described previously, no mortality is 
anticipated or proposed to be authorized for this activity. Below we 
describe how the take is estimated.
    Described in the most basic way, 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. Below, we describe these 
components 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

[[Page 18520]]

reasonably expected to be behaviorally harassed (equated to Level B 
harassment) or to incur PTS of some degree (equated to Level A 
harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2011). 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, drilling) and above 160 dB re 1 [mu]Pa (rms) 
for non-explosive impulsive (e.g., seismic airguns and impact pile 
driving) or intermittent (e.g., scientific sonar) sources.
    WETA'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 for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Technical Guidance, 2016) identifies dual criteria to 
assess auditory injury (Level A harassment) to five different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise from two different types of sources (impulsive or non-impulsive). 
WETA's proposed activity includes the use of impulsive (impact pile 
driving) and non-impulsive (vibratory pile driving) sources.
    These thresholds are provided in the table below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS 2016 Technical Guidance, which may be accessed at: 
https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

[[Page 18521]]

[GRAPHIC] [TIFF OMITTED] TN27AP18.001

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds.
Level B Harassment
    In-Water Disturbance during Vibratory Pile Driving--Level B 
behavioral disturbance may occur incidental to the use of a vibratory 
hammer due to propagation of underwater noise during installation of 
new steel piles. A total of 81 steel piles will be installed at the 
Ferry Terminal. During the 2017 construction season, all piles were 
installed using a vibratory hammer. The hydroacoustic monitoring 
conducted for vibratory driving during the 2017 season has been used to 
establish the expected source values of piles driven during the 2018 
construction season. The SLs were measured at 10 m for the 30- and 36-
in piles and between 9 and 15 m for the 24-in piles. The SLs for 24-in 
piles were calculated using the measured values from 9 to 15 m 
normalized to 10 m. The maximum peak, maximum rms, and mean SEL values 
for each of the pile types (24-, 30-, and 36-in steel piles) were used 
as the SLs to estimate take from vibratory driving. These values are 
provided in Table 4.

                                    Table 4--Sound Source Levels by Pile Type
----------------------------------------------------------------------------------------------------------------
                                                                       Source level at 10 m (dB re 1 [mu]Pa)
                Pile size and installation method                -----------------------------------------------
                                                                       Peak             RMS             SEL
----------------------------------------------------------------------------------------------------------------
24-in Vibratory.................................................             183             165             160

[[Page 18522]]

 
24-in Impact 1 2................................................             193             180             167
30-in Vibratory.................................................             181             157             153
30-in Impact 1 2................................................             200             180             167
36-in Vibratory.................................................             191             173             159
36-in Impact 1 2................................................             200             183             173
----------------------------------------------------------------------------------------------------------------
\1\ Caltrans 2009.
\2\ Impact SLs include 10 dB reduction due to bubble curtain.

    Additionally, monitoring conducted during 2017 construction 
established that for vibratory pile driving in the project area, the 
transmission loss is greater than the standard value of 15 used in 
typical take calculations. For estimating take from vibratory pile 
driving, Level B harassment zones are calculated using the average 
transmission loss measured in 2017 minus one standard deviation of 
those measurements (22.26 - 3.51 = 18.75). Using the calculated 
transmission loss model (18.75logR), the in-water Level B harassment 
zones were determined for each pile size (Table 5). For 24-in steel 
piles driven with a vibratory hammer, the Level B harassment zone is 
expected to be 2,512 m (8,421 ft). For 30-in piles, the Level B 
harassment zone is expected to be 940 m (3,084 ft). For 36-in piles, 
the Level B harassment zone is expected to be 6,709 m (22,011 ft).
    In-Water Disturbance during Impact Pile Driving--As stated 
previously, all piles installed in the 2017 construction season were 
installed solely using a vibratory hammer. However, the use of an 
impact hammer to install piles may be required; therefore, the effects 
of impact pile driving is discussed here. Level B behavioral 
disturbance may occur incidental to the use of an impact hammer due to 
the propagation of underwater noise during the installation of steel 
piles. Piles will be driven to approximately 120 to 140 ft below Mean 
Lower Low Water (MLLW). Installation of these pipe piles may require up 
to 1,800 strikes per piles from an impact hammer using a DelMag D46-32, 
or similar diesel hammer, producing approximately 122,000 foot-pounds 
maximum energy per blow, and 1.5 seconds per blow average.
    Other projects constructed under similar circumstances were 
reviewed to estimate the approximate noise produced by the 24-, 30-, 
and 36-in steel piles. These projects include the driving of similarly 
sized piles at the Alameda Bay Ship and Yacht project, the Rodeo Dock 
Repair project, and the Amorco Wharf Repair Project (Caltrans 2012). 
Bubble curtains will be used during the installation of these piles, 
which, based on guidance provided by Caltrans for a mid-sized steel 
piles (with a diameter greater than 24 but less than 48 in), is 
expected to reduce noise levels by 10 dB rms (Caltrans 2015a).
    Because no impact pile driving was used in the 2017 construction 
season, no site-specific transmission loss measurements exist for this 
project. The Practical Spreading Loss Model (15logR) is used to 
determine the Level B harassment zones for each pile size (Table 5). 
Both 24- and 30-in steel piles have a SL of 180 dB rms re 1 [micro]Pa 
and therefore have the same Level B harassment zone of 215 m (705 ft). 
For 36-in piles, the Level B harassment zone is expected to be 341 m 
(1,120 ft).

                                            Table 5--Pile Driving Source Levels and Level B Harassment Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                              Level B threshold                                         Area of Level B
            Pile size and installation method               Source level (dB   (dB re 1 [mu]Pa      Propagation     Distance to Level   harassment zone
                                                            re 1 [mu]Pa rms)         rms)             (xLogR)        B threshold (m)      (square km)
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Vibratory..........................................                165                120              18.75              2,512               7.30
24-in Impact.............................................            \a\ 180                160                 15                215               0.08
30-in Vibratory..........................................                157                120              18.75                940               1.08
30-in Impact.............................................            \a\ 180                160                 15                215               0.08
36-in Vibratory..........................................                173                120              18.75              6,709               33.5
36-in Impact.............................................            \a\ 183                160                 15                341               0.18
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Impact source levels include 10 dB reduction due to bubble curtain.

Level A Harassment
    When 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 will result in some degree of 
overestimate of Level A 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 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, and the resulting isopleths are reported below.

[[Page 18523]]



                                         Table 6--Inputs for Determining Distances to Cumulative PTS Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                             Number of                       Activity
            Pile size and installation method              Source level    Source level     Propagation     strikes per      Number of       duration
                                                           at 10 m (SEL)   at 10 m (rms)      (xLogR)          pile        piles per day     (seconds)
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Vibratory.........................................  ..............             165           18.75  ..............               4             900
24-in Impact............................................         \a\ 167  ..............              15           1,800               3  ..............
30-in Vibratory.........................................  ..............             157           18.75  ..............               4             900
30-in Impact............................................         \a\ 167  ..............              15           1,800               3  ..............
36-in Vibratory.........................................  ..............             173           18.75  ..............               4           1,200
36-in Impact............................................         \a\ 173  ..............              15           1,800               2  ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Source level includes 10 dB reduction due to bubble curtain.


                                      Table 7--Resulting Level A Isopleths
----------------------------------------------------------------------------------------------------------------
                                                         Distance to Level A threshold (m)
                                 -------------------------------------------------------------------------------
   Pile size and installation                                          High-
             method                Low-frequency   Mid-frequency     frequency        Phocid          Otariid
                                     cetaceans       cetaceans       cetaceans       pinnipeds       pinnipeds
----------------------------------------------------------------------------------------------------------------
24-in Vibratory.................              12               2              17               8              <1
24-in Impact....................             264               9             314             141              10
30-in Vibratory.................               4              <1               6               3              <1
30-in Impact....................             264               9             314             141              10
36-in Vibratory.................              38               5              52              26               3
36-in Impact....................             505              18             602             270              20
----------------------------------------------------------------------------------------------------------------

    The resulting PTS isopleths assume an animal would remain 
stationary at that distance for the duration of the activity. The 
largest isopleths result from impact pile driving. All piles installed 
in the 2017 construction season were driven solely using a vibratory 
hammer indicating that vibratory driving will be the most likely method 
of installation in the 2018 season. Given the short duration within a 
day that impact driving may be conducted and the mitigation measures 
proposed by WETA, Level A take is neither expected nor proposed to be 
authorized.

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
Gray Whale
    Caltrans Richmond-San Rafael Bridge project monitors recorded 12 
living and two dead gray whales in the surveys performed in 2012. All 
sightings were in either the Central or North Bay, and all but two 
sightings occurred during the months of April and May. One gray whale 
was sighted in June and one in October. The Oceanic Society has tracked 
gray whale sightings since they began returning to San Francisco Bay 
regularly in the late 1990s. Most sightings occurred just a mile or two 
inside of the Golden Gate, with some traveling into San Pablo Bay in 
the northern part of the San Francisco Bay (Self 2012). The Oceanic 
Society data show that all age classes of gray whales enter San 
Francisco Bay and they enter as singles or in groups of up to five 
individuals (Winning 2008). It is estimated that two to six gray whales 
enter San Francisco Bay in any given year.
Bottlenose Dolphin
    Bottlenose dolphins are most often seen just within the Golden Gate 
or just east of the bridge when they are present in San Francisco Bay, 
and their presence may depend on the tides (GGCR 2016). Beginning in 
the summer of 2015, one to two bottlenose dolphins have been observed 
frequently swimming in the Oyster Point area of South San Francisco 
(GGCR 2016, 2017; Perlman 2017). Despite this recent occurrence, this 
stock is highly transitory in nature and is not expected to spend 
extended periods of time in San Francisco Bay. However, the number of 
sightings in the Central Bay has increased, suggesting that bottlenose 
dolphins are becoming more of a resident species.
Harbor Porpoise
    In the last six decades, harbor porpoises have been observed 
outside of San Francisco Bay. The few porpoises that entered were not 
sighted past the Central Bay close to the Golden Gate Bridge. In recent 
years, however, there have been increasingly common observations of 
harbor porpoises in central, North, and South San Francisco Bay. 
According to observations by the Golden Gate Cetacean Research team as 
part of their multi-year assessment, over 100 porpoises may be seen at 
one time entering San Francisco Bay and over 600 individual animals 
have been documented in a photo-ID database. Porpoise activity inside 
San Francisco Bay is thought to be related to tide-dependent foraging, 
as well as mating behaviors (Keener 2011; Duffy 2015). Sightings are 
concentrated in the vicinity of the Golden Gate Bridge and Angel 
Island, with fewer numbers sighted south of Alcatraz and west of 
Treasure Island (Keener 2011).
California Sea Lion
    In San Francisco Bay, sea lions haul out primarily on floating K 
docks at Pier 39 in the Fisherman's Wharf area of the San Francisco 
Marine. The Pier 39 haulout is approximately 1.5 miles from the project 
vicinity. The Marine Mammal Center (TMMC) in Sausalito, California has 
performed monitoring surveys at this location since 1991. A maximum of 
1,706 sea lions was seen hauled out during one survey effort in 2009 
(TMMC 2015). Winter numbers are generally over 500 animals (Goals 
Project 2000). In August to September, counts average from 350 to 850 
(NMFS 2004). Of the California sea lions observed, approximately 85 
percent were male. No pupping activity has been observed at this site 
or at other locations in the San Francisco Bay (Caltrans 2012). The 
California sea lions usually frequent Pier 39 in August after

[[Page 18524]]

returning from the Channel Islands (Caltrans 2013). In addition to the 
Pier 39 haulout, California sea lions haul out on buoys and similar 
structures throughout San Francisco Bay. They are mainly seen swimming 
off the San Francisco and Marin shorelines within San Francisco Bay, 
but may occasionally enter the project area to forage.
Northern Fur Seal
    Juvenile northern fur seals occasionally strand during El 
Ni[ntilde]o events (TMMC 2016). In normal years, TMMC admits about five 
northern fur seals that strand on the central California coast. During 
El Ni[ntilde]o years, this number dramatically increases. For example, 
during the 2006 El Ni[ntilde]o event, 33 fur seals were admitted. Some 
of these stranded animals were collected from shorelines in San 
Francisco Bay (TMMC 2016). The shoreline in the vicinity of the project 
is developed waterfront, consisting of piers and wharves where northern 
fur seals are unlikely to strand.
Pacific Harbor Seal
    Long-term monitoring studies have been conducted at the largest 
harbor seal colonies in Point Reyes National Seashore and Golden Gate 
National Recreation Area since 1976. Castro Rocks and other haulouts in 
San Francisco Bay are part of the regional survey area for this study 
and have been included in annual survey efforts. Between 2007 and 2012, 
the average number of adults observed ranged from 126 to 166 during the 
breeding season (March through May), and from 92 to 129 during the 
molting season (June through July) (Truchinski et al., 2008; Flynn et 
al., 2009; Codde et al., 2010, 2011, 2012; Codde and Allen 2015). 
Marine mammal monitoring at multiple locations inside San Francisco Bay 
was conducted by the California Department of Transportation (Caltrans) 
from May 1998 to February 2002, and determined that at least 500 harbor 
seals populate San Francisco Bay (Green et al., 2002). This estimate 
agrees with previous seal counts in the San Francisco Bay, which ranged 
from 524 to 641 seals from 1987 to 1999 (Goals Project 2000).
    Yerba Buena Island is the nearest harbor seal haulout site, with as 
many as 188 individuals observed hauled out. Harbor seals are more 
likely to be hauled out in the late afternoon and evening, and are more 
likely to be in the water during the morning and early afternoon. Tidal 
stage is a major controlling factor of haulout use by harbor seals, 
with more seals present during low tides than high tide periods (Green 
et al., 2002). Therefore, the number of harbor seals in the vicinity of 
Yerba Buena Island will vary throughout the work period.
Northern Elephant Seal
    Northern elephant seals are seen frequently on the California 
coast. Elephant seals aggregate at various sites along the coast to 
give birth and breed from December through March. Pups remain onshore 
or in adjacent shallow water through May. Adults make two foraging 
migrations each year, one after breeding and the second after molting 
(Stewart and DeLong 1995). Most strandings occur in May as young pups 
make their first trip out to sea. When those pups return to their 
rookery sites to molt in late summer and fall, some make brief stops in 
San Francisco Bay. Approximately 100 juvenile elephant seals strand in 
San Francisco Bay each year, including individual strandings at Yerba 
Buena Island and Treasure Island (fewer than 10 strandings per year) 
(Caltrans 2015b).

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    While impact pile driving may be used during this project, all 
piles in the previous year of construction were installed completely 
with vibratory pile driving. Impact driving take calculations are 
included for informational purposes (Tables 8 and 9). However, only 
vibratory pile driving take calculations are conservatively used for 
the take estimation in this IHA as vibratory driving is the most likely 
method of pile installation and results in greater Level B harassment 
zones.
Gray Whale
    Gray whales occasionally enter San Francisco Bay during their 
northward migration period of February and March. Pile driving is not 
proposed to occur during this time and gray whales are not likely to be 
present at other times of the year. It is estimated that two to six 
gray whales enter the Bay in any given year, but they are unlikely to 
be present during the work period (June 1 through November 30). 
However, individual gray whales have occasionally been observed in San 
Francisco Bay during the work period, and therefore it is estimated 
that, at most, one gray whale may be exposed to Level B harassment 
during two days of pile driving if they enter the Level B harassment 
zones (Table 12).
Bottlenose Dolphin
    When bottlenose dolphins are present in San Francisco Bay, they are 
more typically found close to the Golden Gate. Recently, beginning in 
2015, two individuals have been observed frequently in the vicinity of 
Oyster Point (GGCR 2016, 2017; Perlman 2017). The average reported 
group size for bottlenose dolphins is five. Reports show that a group 
normally comes into San Francisco Bay and transits past Yerba Buena 
Island once per week for approximately a two week stint, then leaves 
(NMFS 2017b). Assuming the dolphins come into San Francisco Bay three 
times per year, the group of five dolphins would make six passes 
through the Level B harassment zone for a total of 30 takes (Table 12).
Harbor Porpoise
    A small but growing population of harbor porpoises uses San 
Francisco Bay. Porpoises are usually spotted in the vicinity of Angel 
Island and the Golden Gate Bridge (Keener 2011), but may use other 
areas of the Central Bay in low numbers. During construction activities 
in 2017, marine mammal observers recorded eight sightings of harbor 
porpoises, including a group of two to three individuals that was seen 
three times over the course of the pile-driving season. Harbor 
porpoises generally travel individually or in small groups of two or 
three (Sekiguchi 1995), and a pod of up to four individuals was 
observed in the area south of Yerba Buena Island during the 2017 Bay 
Bridge monitoring window. A pod of four harbor porpoises could 
potentially enter the Level B harassment zone on as many as eight days 
of pile driving, for 32 total takes (Table 12).
California Sea Lion
    Caltrans has conducted monitoring of marine mammals in the vicinity 
of the Bay Bridge for 16 years. From those data, Caltrans has produced 
at-sea density estimates for California sea lions of 0.09 animals per 
square kilometer (0.23 per square mile) for the summer-late fall season 
(Caltrans 2016). Marine mammal monitoring observations from the 2017 
construction season were used to calculate a project-specific estimate 
of take per driving day (1.29 animals per day). Observations from 
marine mammal monitoring in 2017 were assumed to represent the 
occurrence of California sea lions along the waterfront while the 
Caltrans density represents the occurrence of California sea lions in 
open water in the bay. The two numbers were combined to calculate the 
daily

[[Page 18525]]

average take over the entire Level B harassment zone (Table 8).

                                                   Table 8--Estimated Daily California Sea Lion Takes
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Area of Level B     At-sea density                        Takes per day
            Pile size and installation method               harassment zone      (animals per      Takes per day        from 2017      Total daily Level
                                                              (square km)       square km) \a\      from density        monitoring          B takes
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Vibratory..........................................              7.304               0.23               0.66               1.29               1.95
24-in Impact.............................................              0.084               0.23               0.01               1.29               1.30
30-in Vibratory..........................................              1.083               0.23               0.10               1.29               1.39
30-in Impact.............................................              0.084               0.23               0.01               1.29               1.30
36-in Vibratory..........................................             33.497               0.23               3.02               1.29               4.31
36-in Impact.............................................              0.177               0.23               0.02               1.29               1.31
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Caltrans 2016.

    During El Ni[ntilde]o conditions, the density of California sea 
lions in San Francisco Bay may be much greater than the value used 
above. The likelihood of El Ni[ntilde]o conditions occurring in 2018 is 
currently low, with La Ni[ntilde]a conditions expected to develop (NOAA 
2018). However, to account for the potential of El Ni[ntilde]o 
developing in 2018, daily take estimated has been increase by a factor 
of 5 for each pile type (Table 9).

                 Table 9--Estimated Total California Sea Lion Takes From Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
                                                                                                 Total takes by
              Pile size                Number of piles     Number of days      Daily takes            pile
----------------------------------------------------------------------------------------------------------------
24-in...............................                 35                 18               9.75                176
30-in...............................                 18                  9               6.95                 63
36-in...............................                 28                 14              21.55                302
                                     ---------------------------------------------------------------------------
    Total...........................  .................  .................  .................                541
----------------------------------------------------------------------------------------------------------------

Northern Fur Seal
    The incidence of northern fur seals in San Francisco Bay depends 
largely on oceanic conditions, with animals more likely to strand 
during El Ni[ntilde]o events. El Ni[ntilde]o conditions are unlikely to 
develop in 2018 (NOAA 2018) but it is anticipated that up to 10 
northern fur seals may be in San Francisco Bay and enter the Level B 
harassment zone (Table 12) (NMFS 2016b).
Pacific Harbor Seal
    Caltrans has produced at-sea density estimates for Pacific harbor 
seals of 0.83 animals per square kilometer (2.15 per square mile) for 
the fall-winter season (Caltrans 2016). Even though work will 
predominantly occur during the summer, when at-sea density has been 
observed to be lower (Caltrans 2016), the higher value of fall-winter 
density is conservatively used. Additionally, marine mammal monitoring 
observations from the 2017 construction season were used to calculate a 
project-specific estimate of take per driving day (3.18 animals per 
day). Observations from marine mammal monitoring in 2017 were assumed 
to represent the occurrence of harbor seals along the waterfront while 
the Caltrans density represents the occurrence of harbor seals in open 
water in the bay. The two numbers were combined to calculate the daily 
average take over the entire Level B harassment zone (Table 10). The 
daily take and days of pile installation were used to calculate total 
harbor seal Level B takes (Table 11).

                                                       Table 10--Estimated Daily Harbor Seal Takes
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Area of Level B     At-sea density                        Takes per day
            Pile size and installation method               harassment zone      (animals per      Takes per day        from 2017      Total daily Level
                                                              (square km)       square km) \a\      from density        monitoring          B takes
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-in Vibratory..........................................              7.304               0.83               6.06               3.18               9.24
24-in Impact.............................................              0.084               0.83               0.07               3.18               3.25
30-in Vibratory..........................................              1.083               0.83               0.90               3.18               4.08
30-in Impact.............................................              0.084               0.83               0.07               3.18               3.25
36-in Vibratory..........................................             33.497               0.83               27.8               3.18              30.98
36-in Impact.............................................              0.177               0.83               0.15               3.18               3.33
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ Caltrans 2016.


                 Table 11--Estimated Total Pacific Harbor Seal Takes From Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
                                                                                                 Total takes by
              Pile size                Number of piles     Number of days      Daily takes            pile
----------------------------------------------------------------------------------------------------------------
24-in...............................                 35                 18               9.24                166
30-in...............................                 18                  9               4.08                 37
36-in...............................                 28                 14              30.98                434
                                     ---------------------------------------------------------------------------

[[Page 18526]]

 
    Total...........................  .................  .................  .................                637
----------------------------------------------------------------------------------------------------------------

Northern Elephant Seal
    Small numbers of elephant seals haul out or strand on Yerba Buena 
Island and Treasure Island each year. Monitoring of marine mammals in 
the vicinity of the Bay Bridge has been ongoing for 15 years. From 
these data, Caltrans has produced an estimated at-sea density for 
elephant seals of 0.06 animals per square kilometer (0.16 per square 
mile) (Caltrans 2015b). Most sightings of elephant seals occur in 
spring or early summer, and are less likely to occur during the period 
of in-water work for this project. As a result, densities during pile 
driving would be much lower. It is possible that a lone elephant seal 
may enter the Level B harassment zone once per week during the 26 week 
pile driving window (June 1 to November 30) for a total of 26 takes 
(Table 12).

                                                         Table 12--Total Level B Estimated Takes
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            Bottlenose        Harbor      California sea   Northern fur   Pacific harbor     Northern
                                            Gray whale        dolphin        porpoise          lion            seal            seal        elephant seal
--------------------------------------------------------------------------------------------------------------------------------------------------------
Take Estimate...........................               2              30              32             541              10             637              26
--------------------------------------------------------------------------------------------------------------------------------------------------------

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.

Mitigation for Marine Mammals and Their Habitat

General Construction Measures
    A Spill Prevention Control and Countermeasure (SPCC) plan has been 
prepared to address the emergency cleanup of any hazardous material, 
and will be available onsite. The SPCC plan incorporates SPCC, 
hazardous waste, stormwater, and other emergency planning requirements. 
In addition, the project will comply with the Port's stormwater 
regulations. Fueling of land and marine-based equipment will be 
conducted in accordance with procedures outlined in the SPCC. Well-
maintained equipment will be used to perform work, and except in the 
case of a failure or breakdown, equipment maintenance will be performed 
offsite. Equipment will be inspected daily by the operator for leaks or 
spills. If leaks or spills are encountered, the source of the leak will 
be identified, leaked material will be cleaned up, and the cleaning 
materials will be collected and properly disposed. Fresh cement or 
concrete will not be allowed to enter San Francisco Bay. All 
construction materials, wastes, debris, sediment, rubbish, trash, 
fencing, etc. will be removed from the site once project construction 
is complete, and transported to an authorized disposal area.
Pile Driving
    Pre-activity monitoring will take place from 30 minutes prior to 
initiation of pile driving activity and post-activity monitoring will 
continue through 30 minutes post-completion of pile driving activity. 
Pile driving may commence at the end of the 30-minute pre-activity 
monitoring period, provided observers have determined that the shutdown 
zone (described below) is clear of marine mammals, which includes 
delaying start of pile driving activities if a marine mammal is sighted 
in the zone, as described below. A determination that the shutdown zone 
is clear must be made during a period of good visibility (i.e., the 
entire shutdown zone and surrounding waters must be visible to the 
naked eye).
    If a marine mammal approaches or enters the shutdown zone during 
activities or pre-activity monitoring, all pile driving activities at 
that location shall be halted or delayed, respectively. If pile driving 
is halted or delayed due to the presence of a marine mammal, the 
activity may not resume or commence until either the animal has 
voluntarily left and been visually confirmed beyond the shutdown zone 
and 15 or 30 minutes (for pinnipeds/small cetaceans or large cetaceans, 
respectively) have passed without re-detection of the animal. Pile 
driving activities include the time to install or remove a single pile 
or series of piles, as long as the time elapsed between uses of the 
pile driving equipment is no more than thirty minutes.
    For all pile driving activities, a minimum of one protected species 
observed (PSO) will be required,

[[Page 18527]]

stationed at the active pile driving rig or at the best vantage 
point(s) practicable to monitor the shutdown zones for marine mammals 
and implement shutdown or delay procedures when applicable through 
communication with the equipment operator.
    Monitoring of pile driving will be conducted by qualified PSOs (see 
below) who will have no other assigned tasks during monitoring periods. 
WETA will adhere to the following conditions when selecting observers:
     Independent PSOs will be used (i.e., not construction 
personnel);
     At least one PSO must have prior experience working as a 
marine mammal observer during construction activities;
     Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
     WETA will submit PSO CVs for approval by NMFS.
    WETA will ensure that observers have the following additional 
qualifications:
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates, times, and reason for implementation 
of mitigation (or why mitigation was not implemented when required); 
and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    To prevent Level A take of any species, shutdown zones equivalent 
to the Level A harassment zones will be established. If the Level A 
harassment zone is less than 10 m, a minimum 10 m shutdown zone will be 
enforced. WETA will implement shutdown zones as follows:

                                      Table 13--Pile Driving Shutdown Zones
----------------------------------------------------------------------------------------------------------------
                                                                 Shutdown zone (m)
                                 -------------------------------------------------------------------------------
   Pile size and installation                                          High-
             method                Low-frequency   Mid-frequency     frequency        Phocid          Otariid
                                     Cetaceans       cetaceans       cetaceans       pinnipeds       pinnipeds
----------------------------------------------------------------------------------------------------------------
24-in Vibratory.................              12              10              17              10              10
24-in Impact....................             264              10             314             141              10
30-in Vibratory.................              10              10              10              10              10
30-in Impact....................             264              10             314             141              10
36-in Vibratory.................              38              10              52              26              10
36-in Impact....................             505              18             602             270              20
----------------------------------------------------------------------------------------------------------------

    If a species for which authorization has not been granted, or a 
species for which authorization has been granted but the authorized 
takes are met, is observed approaching or within the Level B harassment 
zones (Table 5), pile driving and removal activities must cease 
immediately using delay and shut-down procedures. Activities must not 
resume until the animal has been confirmed to have left the area or 15 
or 30 minutes (pinniped/small cetacean or large cetacean, respectively) 
has elapsed.
    Piles driven with an impact hammer will employ a ``soft start'' 
technique to give fish and marine mammals an opportunity to move out of 
the area before full-powered impact pile driving begins. This soft 
start will include an initial set of three strikes from the impact 
hammer at reduced energy, followed by a 30 second waiting period, then 
two subsequent three-strike sets. Soft start will be required at the 
beginning of each day's impact pile driving work and at any time 
following a cessation of impact pile driving of 30 minutes or longer.
    Impact hammers will be cushioned using a 12-in thick wood cushion 
block. WETA will also employ a bubble curtain during impact pile 
driving. WETA will implement the following performance standards:
     The bubble curtain must distribute air bubbles around 100 
percent of the piling perimeter for the full depth of the water column;
     The lowest bubble ring shall 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
     WETA shall require that construction contractors train 
personnel in the proper balancing of air flow to the bubblers, and 
shall require that construction contractors submit an inspection/
performance report for approval by WETA within 72 hours following the 
performance test. Corrections to the attenuation device to meet the 
performance standards shall occur prior to impact driving.
    Based on our evaluation of the applicant's proposed measures, NMFS 
has preliminarily determined that the proposed mitigation measures 
provide the means effecting the least practicable impact on the 
affected species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, requirements pertaining to 
the monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104 (a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which

[[Page 18528]]

take is anticipated (e.g., presence, abundance, distribution, density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.

Hydroacoustic Monitoring

    WETA's proposed monitoring and reporting is also described in their 
Hydroacoustic Monitoring Plan and Marine Mammal Monitoring Plan, 
available at https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities.
    Hydroacoustic monitoring will be conducted in consultation with the 
California Department of Fish and Wildlife (CDFW) during a minimum of 
ten percent of all impact pile driving activities. Hydroacoustic 
monitoring of vibratory pile driving was completed during the 2017 
construction season and will not be conducted in 2018. Monitoring of 
impact pile driving will be done in accordance with the methodology 
outlined in the Hydroacoustic Monitoring Plan. The monitoring will be 
conducted to achieve the following:
     Be based on the dual metric criteria (Popper et al., 2006) 
and the accumulated SEL;
     Establish field locations that will be used to document 
the extent of the area experiencing 187 dB SEL accumulated;
     Verify the distance of the Marine Mammal Level A 
harassment/shutdown zone and Level B harassment zone thresholds;
     Describe the methods necessary to continuously assess 
underwater noise on a real-time basis, including details on the number, 
location, distance, and depth of hydrophones and associated monitoring 
equipment;
     Provide a means of recording the time and number of pile 
strikes, the peak sound energy per strike, and interval between 
strikes; and
     Provide provisions to provide all monitoring data to the 
CDFW and NMFS.

Visual Marine Mammal Observations

    WETA will collect sighting data and behavioral responses to 
construction for marine mammal species observed in the Level B 
harassment zones during the period of activity. All PSOs will be 
trained in marine mammal identification and behaviors and are required 
to have no other construction-related tasks while conducting 
monitoring. WETA proposes to use one PSO to monitor the shutdown zones 
and Level B harassment zone. During previous hydroacoustic monitoring 
for the Bay Bridge construction and demolition, it has not been 
possible to detect or distinguish sound from vibratory pile driving 
beyond 1,000 to 2,000 m (3,280 to 6,562 ft) from the source (Rodkin 
2009). Thus, the monitoring zone for the vibratory driving of 24- and 
36-in piles will be set at 2,000 m (6,562 ft). The monitoring zone for 
the vibratory driving of 30-in piles will be set equivalent to the 
Level B harassment zone (940 m, 3,084 ft). The PSO will monitor the 
shutdown zones and monitoring zones before, during, and after pile 
driving. Based on our requirements, WETA will implement the following 
procedures for pile driving and removal:
     The PSO will be located at the best vantage point in order 
to properly see the entire shutdown zone and as much of the monitoring 
zone as possible;
     During all observation periods, the observer will use 
binoculars and the naked eye to search continuously for marine mammals;
     If the shutdown zones are obscured by fog or poor lighting 
conditions, pile driving will not be initiated until that zone is 
visible. Should such conditions arise while pile driving is underway, 
the activity would be halted; and
     The shutdown and monitoring zones will be monitored for 
the presence of marine mammals before, during, and after any pile 
driving activity.
    PSOs implementing the monitoring protocol will assess its 
effectiveness using an adaptive approach. The monitoring biologist will 
use their best professional judgment throughout implementation and seek 
improvements to these methods when deemed appropriate. Any 
modifications to the protocol will be coordinated between NMFS and 
WETA.
    In addition, the PSO will survey the Level A and Level B harassment 
zones (areas within approximately 2,000 ft of the pile-driving area 
observable from the shore) on two separate days--no earlier than seven 
days before the first day of construction--to establish baseline 
observations. Monitoring will be timed to occur during various tides 
(preferably low and high tides) during daylight hours from locations 
that are publicly accessible (e.g., Pier 14 or the Ferry Plaza). The 
information collected from baseline monitoring will be used for 
comparison with results of monitoring during pile-driving activities.

Data Collection

    WETA will record detailed information about any implementation of 
shutdowns, including the distance of animals to the pile and 
description of specific actions that ensued and resulting behavior of 
the animal, if any. In addition, WETA will attempt to distinguish 
between the number of individual animals taken and the number of 
incidences of take. We require that, at a minimum, the following 
information be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, age and sex class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel, and if possible, 
the correlation to SPLs;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Description of implementation of mitigation measures 
(e.g., shutdown or delay);
     Locations of all marine mammal observations; and
     Other human activity in the area.

Reporting

    A draft report will be submitted to NMFS within 90 days of the 
completion of marine mammal monitoring, or sixty days prior to the 
requested date of issuance of any future IHA for projects

[[Page 18529]]

at the same location, whichever comes first. The report will include 
marine mammal observations pre-activity, during-activity, and post-
activity during pile driving and removal days, and will also provide 
descriptions of any behavioral responses to construction activities by 
marine mammals and a complete description of all mitigation shutdowns 
and the results of those actions and an extrapolated total take 
estimate based on the number of marine mammals observed during the 
course of construction. A final report must be submitted within 30 days 
following resolution of comments on the draft report.

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).
    Pile driving activities associated with the ferry terminal 
construction project, as outlined previously, have the potential to 
disturb or displace marine mammals. Specifically, the specified 
activities may result in take, in the form of Level B harassment 
(behavioral disturbance) only, from underwater sounds generated from 
pile driving and removal. Potential takes could occur if individuals of 
these species are present in the ensonified zone when pile driving and 
removal occurs.
    No injury, serious injury, or mortality is anticipated given the 
nature of the activities and measures designed to minimize the 
possibility of injury to marine mammals. The potential for these 
outcomes is minimized through the construction method and the 
implementation of the planned mitigation measures. Specifically, 
vibratory hammers will be the primary method of installation (impact 
driving is included only as a contingency). Impact pile driving 
produces short, sharp pulses with higher peak levels and much sharper 
rise time to reach those peaks. If impact driving is necessary, 
implementation of soft start and shutdown zones significantly reduces 
any possibility of injury. Given sufficient ``notice'' through use of 
soft start (for impact driving), marine mammals are expected to move 
away from a sound source that is annoying prior to it becoming 
potentially injurious. WETA will also employ the use of 12-in-thick 
wood cushion block on impact hammers, and a bubble curtain as sound 
attenuation devices. Environmental conditions in San Francisco Ferry 
Terminal mean that marine mammal detection ability by trained observers 
is high, enabling a high rate of success in implementation of shutdowns 
to avoid injury.
    WETA's activities are localized and of relatively short duration (a 
maximum of 41 days of pile driving over the work season). The entire 
project area is limited to the San Francisco ferry terminal area and 
its immediate surroundings. These localized and short-term noise 
exposures may cause short-term behavioral modifications in harbor 
seals, northern fur seals, northern elephant seals, California sea 
lions, harbor porpoises, bottlenose dolphins, and gray whales. 
Moreover, the planned mitigation and monitoring measures are expected 
to reduce the likelihood of injury and behavior exposures. 
Additionally, no important feeding and/or reproductive areas for marine 
mammals are known to be within the ensonified area during the 
construction time frame.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The project activities 
will not modify existing marine mammal habitat for a significant amount 
of time. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range; but, because 
of the short duration of the activities and the relatively small area 
of the habitat that may be affected, the impacts to marine mammal 
habitat are not expected to cause significant or long-term negative 
consequences.
    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. Thus, even repeated Level B 
harassment of some small subset of the overall stock is unlikely to 
result in any significant realized decrease in fitness for the affected 
individuals, and thus will not result in any adverse impact to the 
stock as a whole.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No mortality is anticipated or authorized;
     Injurious takes are not expected due to the presumed 
efficacy of the planned mitigation measures in reducing the effects of 
the specified activity to the level of least practicable impact;
     Level B harassment may consist of, at worst, temporary 
modifications in behavior (e.g., temporary avoidance of habitat or 
changes in behavior);
     The lack of important feeding, pupping, or other areas in 
the action area;
     The high level of ambient noise already in the ferry 
terminal area; and
     The small percentage of the stock that may be affected by 
project activities (less than seven percent for all species).
    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.

[[Page 18530]]

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.
    Table 12 details the number of instances that animals could be 
exposed to received noise levels that could cause Level B harassment 
for the planned work at the ferry terminal project site relative to the 
total stock abundance. The instances of take proposed to be authorized 
to be taken for all stocks are considered small relative to the 
relevant stocks or populations even if each estimated instance of take 
occurred to a new individual--an unlikely scenario. The total percent 
of the population (if each instance was a separate individual) for 
which take is requested is approximately seven percent for bottlenose 
dolphins, two percent for harbor seals, and less than one percent for 
all other species (Table 14). For pinnipeds occurring in the vicinity 
of the ferry terminal, there will almost certainly be some overlap in 
individuals present day-to-day, and the number of individuals taken is 
expected to be notably lower. Similarly, the number of bottlenose 
dolphins that could be subject to Level B harassment is expected to be 
a single pod of five individuals exposed up to six times over the 
course of the project.

                 Table 14-- Estimated Numbers and Percentage of Stocks Proposed To Be Authorized
----------------------------------------------------------------------------------------------------------------
                                                                                       Stock       Percentage of
                             Species                                Authorized       abundance      total stock
                                                                       takes         Estimate           (%)
----------------------------------------------------------------------------------------------------------------
Gray whale (Eschrichtius robustus)..............................               2          20,990            0.01
Eastern North Pacific stock.....................................
Bottlenose dolphin (Tursiops truncatus).........................              30             453             6.9
California coastal stock........................................
Harbor Porpoise (Phocoena phocoena).............................              32           9,886            0.32
San Francisco-Russian River Stock...............................
California sea lion (Zalophus californianus)....................             541         296,750            0.18
U.S. Stock......................................................
Northern fur seal (Callorhinus ursinus).........................              10          14,050            0.07
California stock................................................
Pacific harbor seal (Phoca vitulina richardii)..................             637          30,968            2.06
California stock................................................
Northern elephant seal (Mirounga angustirostris)................              26         179,000            0.01
California breeding stock.......................................
----------------------------------------------------------------------------------------------------------------

    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

    There are no relevant subsistence uses of the affected marine 
mammal stocks or species implicated by this action. Therefore, NMFS has 
preliminarily determined that the total taking of affected species or 
stocks would not have an unmitigable adverse impact on the availability 
of such species or stocks for taking for subsistence purposes.

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat.
    No incidental take of ESA-listed species is proposed for 
authorization or expected to result from this activity. Therefore, NMFS 
has determined that formal consultation under section 7 of the ESA is 
not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to WETA for conducting their Downtown San Francisco Ferry 
Terminal Expansion Project, South Basin Improvements Project in San 
Francisco, CA, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. This IHA would 
be valid from June 1, 2018 to May 31, 2019. This section contains a 
draft of the IHA itself. The wording contained in this section is 
proposed for inclusion in the IHA (if issued).
    The San Francisco Bay Area Water Emergency Transportation Authority 
(WETA) is hereby authorized under section 101(a)(5)(D) of the Marine 
Mammal Protection Act (MMPA; 16 U.S.C. 1371(a)(5)(D)) to harass marine 
mammals incidental to conducting their Downtown San Francisco Ferry 
Terminal Expansion Project, South Basin Improvements Project in San 
Francisco, California (CA), when adhering to the following terms and 
conditions.
    1. This Incidental Harassment Authorization (IHA) is valid for one 
year from June 1, 2018 through May 31, 2018.
    2. This IHA is valid only for pile driving activities associated 
with the Downtown San Francisco Ferry Terminal Expansion Project, South 
Basin Improvements Project in San Francisco Bay, CA.
    3. General Conditions
    (a) A copy of this IHA must be in the possession of WETA, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking are summarized in Table 1.
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b). See Table 1 (attached) for numbers of 
take authorized.

[[Page 18531]]

    (d) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in condition 3(b) of the 
Authorization or any taking of any other species of marine mammal is 
prohibited and may result in the modification, suspension, or 
revocation of this IHA.
    (e) WETA shall conduct briefings between construction supervisors 
and crews, marine mammal monitoring team, acoustical monitoring team, 
and WETA staff prior to the start of all pile driving activities, and 
when new personnel join the work, in order to explain responsibilities, 
communication procedures, marine mammal monitoring protocol, and 
operational procedures.
    4. Mitigation Measures
    The holder of this Authorization is required to implement the 
following mitigation measures:
    (a) For in-water heavy machinery work other than pile driving 
(e.g., standard barges, tug boats, barge-mounted excavators, or 
clamshell equipment used to place or remove material), if a marine 
mammal comes within 10 meters, operations shall cease and vessels shall 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions.
    (b) For all pile driving, WETA shall implement shutdown zones 
equivalent to the Level A harassment zones. If the calculated Level A 
harassment zone is less than 10 m, WETA shall implement a minimum 10 m 
shutdown zone. Table 2 outlines the shutdown zones for each pile 
driving activity.
    (c) If a species for which authorization has not been granted 
(including, but not limited to, Guadalupe fur seals and humpback 
whales) or if a species for which authorization has been granted but 
the authorized takes are met, approaches or is observed within the 
Level B harassment zone, activities shall shut down immediately and 
shall not restart until the animals have been confirmed to have left 
the area.
    (d) WETA shall establish monitoring protocols as described below.
    (i) For all pile driving activities, a Protected Species Observer 
(PSO) shall be employed to achieve optimal monitoring of the shutdown 
zones and the surrounding waters of the ferry terminal and San 
Francisco Bay.
    (ii) This observer shall record all observations of marine mammals, 
regardless of distance from the pile being driven, as well as behavior 
and potential behavioral reactions of the animals. Observations within 
the ferry terminal shall be distinguished from those in the nearshore 
waters of San Francisco Bay.
    (iii) The observer shall be equipped for commotional of marine 
mammal observations to relevant personnel (e.g., those necessary to 
effect activity delay or shutdown).
    (iv) Pre-activity monitoring shall take place from 30 minutes prior 
to initiation of pile driving activity and post-activity monitoring 
shall continue through 30 minutes post-completion of pile driving 
activity. Pile driving may commence at the end of the 30-minute pre-
activity monitoring period, provided observers have determined that the 
shutdown zone is clear of marine mammals, which includes delaying start 
of pile driving activities if a marine mammal is sighted in the zone.
    (v) If a marine mammal approaches or enters the shutdown zone 
during activities or pre-activity monitoring, all pile driving 
activities at that location shall be halted or delayed, respectively. 
If pile driving is halted or delayed due to the presence of a marine 
mammal, the activity may not resume or commence until either the animal 
has voluntarily left and been visually confirmed beyond the shutdown 
zone and 15 minutes have passed without re-detection of the pinniped or 
small cetacean, or 30 minutes have passed without re-detection of the 
gray whale. Pile driving activities include the time to install or 
remove a single pile or series of piles, as long as the time elapsed 
between uses of the pile driving equipment is no more than thirty 
minutes.
    (e) WETA shall use soft start techniques when impact pile driving. 
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. Soft start shall 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.
    (f) WETA shall employ a bubble curtain during impact pile driving 
of steel piles and shall implement the following performance standards:
    (i) The bubble curtain must distribute air bubbles around 100 
percent of the piling perimeter for the full depth of the water column.
    (ii) The lowest bubble ring shall 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.
    5. Monitoring
    The holder of this Authorization is required to conduct marine 
mammal monitoring during pile driving activities. Monitoring and 
reporting shall be conducted in accordance with the Monitoring Plan.
    (a) WETA shall collect sighting data and behavioral responses to 
pile driving for marine mammal species observed in the monitoring zones 
during the period of activity. All observers shall be trained in marine 
mammal identification and behaviors, and shall have no other 
construction-related tasks while conducting monitoring.
    (b) WETA shall adhere to the following conditions when selecting 
observers:
    (i) Independent PSOs must be used (i.e., not construction 
personnel);
    (ii) At least one PSOs must have prior experience working as a 
marine mammal observer during construction activities;
    (iii) Other PSOs may substitute education (degree in biological 
science or related field) or training for experience; and
    (iv) WETA shall submit PSO CVs for approval by NMFS.
    (c) WETA shall ensure that observers have the following additional 
qualifications:
    (i) Ability to conduct field observations and collect data 
according to assigned protocols;
    (ii) Experience or training in the field identification of marine 
mammals, including the identification of behaviors;
    (iii) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    (iv) 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 reasons for implementation of mitigation 
(or why mitigation was not implemented when required); and marine 
mammal behavior; and
    (v) 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.
    6. Reporting
    The holder of this Authorization is required to:
    (a) Submit a draft report on all monitoring conducted under the IHA 
within ninety calendar days of the completion of marine mammal and 
acoustic monitoring, or sixty days prior to the issuance of any 
subsequent IHA for this project, whichever comes first. A final report 
shall be prepared and submitted within thirty days following

[[Page 18532]]

resolution of comments on the draft report from NMFS. This report must 
contain the informational elements described in the Monitoring Plan, at 
minimum (see https://www.fisheries.noaa.gov/national/marine-mammal-protection/incidental-take-authorizations-construction-activities), and 
shall also include:
    (i) Detailed information about any implementation of shutdowns, 
including the distance of animals to the pile driving location and 
description of specific actions that ensued and resulting behavior of 
the animal, if any.
    (ii) Description of attempts to distinguish between the number of 
individual animals taken and the number of incidences of take, such as 
ability to track groups or individuals.
    (iii) An estimated total take extrapolated from the number of 
marine mammals observed during the course of construction activities, 
if necessary.
    (b) Reporting injured or dead marine mammals:
    (i) In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this IHA, 
such as an injury (Level A harassment), serious injury, or mortality, 
WETA shall immediately cease the specified activities and report the 
incident to the Office of Protected Resources, NMFS, and the West Coast 
Regional Stranding Coordinator, NMFS. The report must include the 
following information:
    (1) Time and date of the incident;
    (2) Description of the incident;
    (3) Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    (4) Description of all marine mammal observations and active sound 
source use in the 24 hours preceding the incident;
    (5) Species identification or description of the animal(s) 
involved;
    (6) Fate of the animal(s); and
    (7) Photographs or video footage of the animal(s).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with WETA to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. WETA may not resume 
their activities until notified by NMFS.
    (ii) In the event that WETA 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), WETA shall immediately report 
the incident to the Office of Protected Resources, NMFS, and the West 
Coast Regional Stranding Coordinator, NMFS. The report must include the 
same information identified in 6(b)(i) of this IHA. Activities may 
continue while NMFS reviews the circumstances of the incident. NMFS 
will work with WETA to determine whether additional mitigation measures 
or modifications to the activities are appropriate.
    (iii) In the event that WETA 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 activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), WETA shall report the incident to 
the Office of Protected Resources, NMFS, and the West Coast Regional 
Stranding Coordinator, NMFS, within 24 hours of the discovery. WETA 
shall provide photographs or video footage or other documentation of 
the stranded animal sighting to NMFS.
    7. This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein, or if 
NMFS determines the authorized taking is having more than a negligible 
impact on the species or stock of affected marine mammals.

                    Table 15--Authorized Take Numbers
------------------------------------------------------------------------
                                                  Authorized take
                 Species                 -------------------------------
                                              Level A         Level B
------------------------------------------------------------------------
Harbor seal.............................               0             637
California sea lion.....................               0             541
Northern elephant seal..................               0              26
Northern fur seal.......................               0              10
Harbor porpoise.........................               0              32
Gray whale..............................               0               2
Bottlenose dolphin......................               0              30
------------------------------------------------------------------------


                                      Table 16--Pile Driving Shutdown Zones
----------------------------------------------------------------------------------------------------------------
                                                                 Shutdown zone (m)
                                 -------------------------------------------------------------------------------
   Pile size and installation                                          High-
             method                Low-frequency   Mid-frequency     frequency        Phocid          Otariid
                                     cetaceans       cetaceans       cetaceans       pinnipeds       pinnipeds
----------------------------------------------------------------------------------------------------------------
24-in Vibratory.................              12              10              17              10              10
24-in Impact....................             264              10             314             141              10
30-in Vibratory.................              10              10              10              10              10
30-in Impact....................             264              10             314             141              10
36-in Vibratory.................              38              10              52              26              10
36-in Impact....................             505              18             602             270              20
----------------------------------------------------------------------------------------------------------------

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 
[action]. 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.

[[Page 18533]]

    On a case-by-case basis, NMFS may issue a second one-year IHA 
without additional notice when (1) another year of identical or nearly 
identical activities as described in the Specified Activities section 
is planned or (2) the activities 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, 
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.
     The request for renewal must include the following:
    (1) An explanation that the activities to be conducted beyond the 
initial dates either are identical to the previously analyzed 
activities or include changes so minor (e.g., reduction in pile size) 
that the changes do not affect the previous analyses, take estimates, 
or mitigation and monitoring requirements; 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.
     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 remain the same and appropriate, 
and the original findings remain valid.

    Dated: April 24, 2018.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2018-08888 Filed 4-26-18; 8:45 am]
 BILLING CODE 3510-22-P