[Federal Register Volume 83, Number 163 (Wednesday, August 22, 2018)]
[Notices]
[Pages 42465-42490]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2018-18056]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XG105


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Mission Bay Ferry and Water 
Taxi Landing Project in San Francisco Bay, California

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

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

-----------------------------------------------------------------------

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

DATES: Comments and information must be received no later than 
September 21, 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 <a href="/cdn-cgi/l/email-protection#521b06027c203736363b3c35123c3d33337c353d24"><span class="__cf_email__" data-cfemail="733a27235d011617171a1d14331d1c12125d141c05">[email protected]</span></a>.
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted online at https://www.fisheries.noaa.gov/node/23111 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: Gray Redding, 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

    The MMPA prohibits the ``take'' of marine mammals, with certain 
exceptions. Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 
et seq.) direct the Secretary of Commerce (as delegated to NMFS) to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region if certain findings are made and either regulations 
are issued or, if the taking is limited to harassment, a notice of a 
proposed incidental take authorization may be provided to the public 
for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s) and will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for taking for subsistence uses 
(where relevant). Further, NMFS must prescribe the permissible methods 
of taking and other ``means of effecting the least practicable 
[adverse] impact'' on the affected species or stocks and their habitat, 
paying particular attention to rookeries, mating grounds, and areas of 
similar significance, and on the availability of such species or stocks 
for taking for certain subsistence uses (referred to in shorthand as 
``mitigation''); and requirements pertaining to the mitigation, 
monitoring and reporting of such takings are set forth. The definitions 
of all applicable MMPA statutory terms cited above are included in the 
relevant sections below.

[[Page 42466]]

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 November 2, 2017, NMFS received a request from the Port of San 
Francisco for an IHA to take marine mammals incidental to pile driving 
and drilling in San Francisco Bay. NMFS determined that a revised 
version of the Port's application was adequate and complete on June 22, 
2018. The Port of San Francisco's request is for take of seven species 
of marine mammals by Level B harassment only. Neither the Port of San 
Francisco nor NMFS expects serious injury or mortality to result from 
this activity and, therefore, an IHA is appropriate.

Description of Proposed Activity

Overview

    The port of San Francisco proposes to construct the Mission Bay 
Ferry Landing (MBFL) and Water Taxi Landing (WTL) on San Francisco Bay, 
within the Port of San Francisco's Southern Waterfront in the Mission 
Bay/Central Waterfront area (see Figure 1 of IHA Application). The 
project's proposed activities that have the potential to take marine 
mammals include vibratory and impact pile driving, vibratory pile 
removal, and down the hole drilling. In addition, the project will 
include dredging, however authorization of take from this activity is 
neither requested nor proposed for authorization.
    The Mission Bay Ferry Landing, a single[hyphen]float, 
two[hyphen]berth ferry landing will provide critical regional ferry 
service to and from the Mission Bay neighborhood, one of the fastest 
growing neighborhoods in San Francisco, as well as the Dogpatch, 
Potrero Hill, Pier 70, and the Central Waterfront neighborhoods. The 
separate single float, two[hyphen]berth Water Taxi Landing will provide 
local water taxi access to the Mission Bay area and surrounding 
neighborhoods.

Dates and Duration

    The Port of San Francisco's construction, including dredging, 
vibratory and impact pile driving, and drilling for installation of the 
pier and floating docks will occur from June through November of 2019 
(environment working windows for dredging in this region of the San 
Francisco Bay established by the San Francisco Bay Long Term Management 
Strategy (LTMS Agencies, 2001). The maximum number of construction days 
possible, including dredging and all other activities, is 55 days. The 
maximum total number of days for pile installation and removal are 15 
days.

Specific Geographic Region

    As stated, the project is located in San Francisco Bay within the 
Port of San Francisco's Southern Waterfront in the Mission Bay/Central 
Waterfront area. The specific geographic location for the project is 
provided in Figures 1 and 2 of the IHA Application. The project site is 
approximately three kilometers south of the San Francisco-Oakland Bay 
Bridge, on the western side of San Francisco Bay in the Central Basin. 
The nearby waterfront is an active recreational and commercial port and 
shipyard.

Detailed Description of Specific Activity

Demolition
    Based on preliminary bathymetric surveys and historic information, 
The Port anticipates that buried remnants of concrete and wood debris 
from Pier 64-66 apron may be encountered within the Ferry Landing 
dredge boundary. All debris encountered during dredging operations will 
be removed and disposed of at an approved upland location.
    In addition, existing piles will be pulled with a cable choker or 
removed with a vibratory hammer and every effort will be made to remove 
the entire pile length. If it is necessary to utilize vibratory hammer 
to remove a pile the process will consist of approximately 1-2 minutes 
of initial vibratory use while pulling the pile up to loosen it from 
the sediment. The barge/crane then moves to the next pile to loosen. 
The operator will do this for five to eight piles then remove the 
vibratory driver and go back to dead pull the loosened piles and place 
them on a debris barge for disposal at a permitted facility. The 
vibratory use is minimal to just loosen the pile. Noise generated from 
the operation of the vibratory hammer is expected to result in the 
behavioral disturbance of marine mammals and, therefore, take 
authorization is requested, and accounted for in the ``Take Calculation 
and Estimation'' section below.
Dredging
    Dredging of approximately 129,374 cubic yards will be conducted to 
a depth of -15 feet (ft) MLLW +2 ft of overdepth within the Ferry 
Landing dredge boundary, and to a depth of -8ft MLLW +1 ft overdepth 
within the Water Taxi Landing dredge boundary.
    Best Management Practices (BMPs) will be detailed in a Dredge 
Operations Plan (DOP) submitted to the regulatory agencies for approval 
before dredging begins, and implemented. Dredging will be performed 
from a barge[hyphen]mounted crane with a clam shell bucket. Sediment 
will be transferred into adjacent barges for transport to permitted 
placement site(s). All debris encountered during dredging operations 
will be removed and disposed of at an approved upland location. Noise 
measurements of dredging activities are rare in the literature, but 
dredging is considered to be a low-impact activity for marine mammals, 
producing non-pulsed sound and being substantially quieter in terms of 
acoustic energy output than sources such as seismic airguns and impact 
pile driving. Noise produced by dredging operations has been compared 
to that produced by a commercial vessel travelling at modest speed 
(Robinson et al., 2011). Further discussion of dredging sound 
production may be found in the literature (e.g., Richardson et al., 
1995, Nedwell et al., 2008, Parvin et al., 2008, Ainslie et al., 2009). 
Generally, the effects of dredging on marine mammals are not expected 
to rise to the level of a take. As stated, take is highly unlikely and 
is not proposed to be authorized for dredging activities.
Pile Installation
    A total of 28 permanent piles will be installed as part of this 
project. Four 24-inch concrete piles will be installed on land above 
the mean highwater (MHW)

[[Page 42467]]

line, and the remaining piles will all be installed in-water as 
outlined in Table 1.
    Concrete piles used for in[hyphen]water construction of the pier 
structure for the Mission Bay Ferry Landing will involve the temporary 
installation of a steel caisson sleeve followed by drilling of the rock 
socket, with this installation and drilling process outlined below. 
Four 14-inch steel H piles will be driven with a vibratory driver to 
provide support for a 30-inch steel caisson sleeve, a large tubular 
steel pile. The steel sleeve will also be installed using a vibratory 
driver until refusal. Once the caisson is in place, sediment/soil/rock 
within the caisson will be drilled out using a Bauer BG18 drill or 
similar. All drilled sediment/soil/rock will be collected for disposal 
and transported to an appropriate permitted facility. The concrete 
piles are then inserted after the hole has been drilled. The 24-inch 
concrete piles will then be placed/seated in bedrock for grouting then 
the outer caisson and four H[hyphen]piles will be pulled. Figure 3 in 
the IHA Application provides a depiction of this process. This method 
of construction creates less overall noise and turbidity during 
installation than driven piles. Drilling also is beneficial as it 
reduces the stress and therefore chance of breakage or damage to the 
pile during installation. Overall, ten 24-inch octagonal concrete piles 
will be driven using these methods, including down the hole drilling. 
Authorization of take by Level B harassment was requested and is 
proposed for authorization by NMFS for drilling activities associated 
with 24-inch concrete piles.
    For the remaining piles, noise generated by vibratory and/or impact 
hammers is expected to result in the disturbance of marine mammals and, 
therefore, authorization of incidental take is proposed. Eight 36-inch 
steel piles for the MBFL guide piles and donut fenders and two 16-inch 
steel piles for the WTL platform will be installed with a combination 
of vibratory driver and/or impact hammer. The four remaining 20-inch 
square concrete piles to be installed in-water will be installed with 
an impact hammer.
    The Port estimates a production rate for pile driving of two to six 
piles per day, resulting in a 15 days of pile driving and removal as 
outlined in Table 1. Piles installed using an impact hammer will use a 
Delmag D36/D46/D62 or similar diesel hammer. An overview of the sound 
source levels for this pile installation can be found in Table 3. It 
should be noted that the contractor will be instructed to implement 
vibratory installation as much as possible.
    All pile driving will be performed in compliance with the ``U.S. 
Army Corps of Engineers Proposed Procedures for Permitting Projects 
that will Not Adversely Affect Selected Listed Species in California'' 
and the associated USFWS and NMFS section 7 consultation documents 
associated with these procedures.

                                 Table 1--Summary of In Water Pile Installation
----------------------------------------------------------------------------------------------------------------
                                   Pile
  Locations    Project element   diameter      Pile type     Number of       Method      Piles/day  Construction
                                  (inch)                       piles                                    days
----------------------------------------------------------------------------------------------------------------
Debris Removal................         12  Steel...........         12  If necessary, a         12
                                                                         vibratory
                                                                         hammer will be
                                                                         used to remove
                                                                         up to 12 piles
                                                                         60-120 seconds/
                                                                         pile while
                                                                         pulling the
                                                                         pile up to
                                                                         loosen it from
                                                                         the sediment.
----------------------------------------------------------------------------------------------------------------
MBFL........  Pier............         14  H-pile steel....          4  Four 14-inch             4            10
                                       30  Steel caisson...          1   steel H beams           1
                                       24  Octagonal                10   will be driven          1
                                            concrete.                    with Vibratory
                                                                         Driver 600
                                                                         seconds/pile
                                                                         to support 30-
                                                                         inch steel
                                                                         caisson sleeve
                                                                         driven with
                                                                         Vibratory
                                                                         Driver (900
                                                                         sec/pile) to
                                                                         refusal, drill
                                                                         out hole
                                                                         removing
                                                                         soils, place
                                                                         and position
                                                                         concrete pile,
                                                                         grout pile in
                                                                         place while
                                                                         simultaneously
                                                                         pulling the
                                                                         caisson.
              Float Guide              36  Steel...........          6  Vibratory                5             2
               Piles.                                                    Driver 1200
                                                                         sec/pile then
                                                                         Impact Hammer
                                                                         last 15 ft
                                                                         (150 strikes/
                                                                         pile ~20
                                                                         minutes);
                                                                         bubble curtain
                                                                         will be used
                                                                         during impact
                                                                         duration.
              Donut Fender             36  Steel...........          2  Vibratory                5  ............
               Piles.                                                    Driver 1200
                                                                         sec/pile then
                                                                         Impact Hammer
                                                                         last 15 ft
                                                                         (150 strikes/
                                                                         pile ~20
                                                                         minutes);
                                                                         bubble curtain
                                                                         will be used
                                                                         during impact
                                                                         duration.
WTL.........  Platform........         16  Steel...........          2  Vibratory                2             1
                                                                         Driver 600 sec/
                                                                         pile then
                                                                         Impact Hammer
                                                                         last 15 ft
                                                                         (500 strikes/
                                                                         pile ~20
                                                                         minutes);
                                                                         bubble curtain
                                                                         will be used
                                                                         during impact
                                                                         duration.
              Guide Piles.....         20  Square Concrete.          4  Impact Hammer            4             1
                                                                         500 strikes/
                                                                         pile (max 20
                                                                         minutes); if
                                                                         necessary
                                                                         bubble curtain
                                                                         will be used
                                                                         during impact
                                                                         duration.
----------------------------------------------------------------------------------------------------------------

Installation of Ferry Landing Structural Elements
    Installation of the pier deck, pier canopy, float, and gangway 
would be conducted from land and water-based vessels. This work would 
include the use of generators, cranes, and other heavy equipment but is 
not expected to result in any harassment of marine mammals. Therefore, 
no take is requested or proposed for authorization for these 
activities.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of Specified Activities

    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior

[[Page 42468]]

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; https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments) and 
more general information about these species (e.g., physical and 
behavioral descriptions) may be found on NMFS's website (https://www.fisheries.noaa.gov/find-species).
    Table 2 lists all species with expected potential for occurrence in 
the Mission Bay/Central Waterfront area of San Francisco Bay 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 the Committee on 
Taxonomy (2017). 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 
NMFS neither anticipates nor proposes to authorize mortality 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. 2017 SARs (Carretta et al., 2017). All values presented in 
Table 2 are the most recent available at the time of publication and 
are available in the 2017 SARs (Carretta et al., 2017).

--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                            Stock  abundance  (CV,
                                                                                        ESA/ MMPA  status;    Nmin,  most recent               Annual  M/
             Common name                  Scientific name               Stock             strategic  (Y/N)  abundance  survey) \2\     PBR       SI \3\
                                                                                                \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          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).
                                                               Eastern North Pacific..  -/-; N              626,734 (n/a, 530,474,     11,405        1.1
                                                                                                             2014).
Guadalupe fur seal..................  Arctocephalus townsendi  Mexico to California...  T/D; Y              20,000 (n/a, 15,830,          542       >3.2
                                                                                                             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 angustirostris  California Breeding....  -/-; N              179,000 (n/a, 81,368,       4,882        8.8
                                                                                                             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: https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-stock-assessments assessments. 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 NMFSs SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value or range. A CV associated
  with estimated mortality due to commercial fisheries is presented in some cases.
Note: Italicized species are not expected to be taken or proposed for authorization.

    All species that could potentially occur in the Port's proposed 
project area in San Francisco Bay are included in Table 2. However, the 
temporal and/or spatial occurrence of humpback whale and Guadalupe fur 
seal 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

[[Page 42469]]

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 2017a). Because 
Guadalupe fur seals are highly rare in the area, and sightings are 
associated with abnormal weather conditions, such as El Ni[ntilde]o 
events, NMFS has determined that no Guadalupe fur seals are likely to 
occur in the project vicinity and, therefore, no take is expected to 
occur.

Harbor Seal

    Harbor seals are found from Baja California to the eastern Aleutian 
Islands of Alaska. The species primarily hauls out on remote mainland 
and island beaches and reefs, and estuary areas. Harbor seals tend to 
forage locally within 53 miles (mi) (85 kilometers (km)) of haul-out 
sites (Harvey and Goley 2011). Harbor seal is the most common marine 
mammal species observed in the Bay and individuals are commonly seen 
near the San Francisco-Oakland Bay Bridge east span (CalTrans 2013b, 
2013c). Tagging studies have shown that most seals tagged in the Bay 
remain in the Bay (Harvey and Goley 2011; Manugian 2013). Foraging 
often occurs in the Bay, as noted by observations of seals exhibiting 
foraging behavior (short dives less than five minutes, moving back and 
forth in an area, and sometimes tearing up prey at the surface).

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. Western North Pacific Gray whales have summer and 
fall feeding grounds in the Okhotsk Sea off northeast Sakhalin Island, 
Russia, and off southeastern Kamchatka in the Bering Sea (NMFS 2017c), 
so they would not be expected to occur in San Francisco Bay during 
construction activity for this project. 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 Biologically Important Area for the northward 
progression of gray whales (Calambokidis et al., 2015). During this 
time, recently pregnant females, adult males, immature females, and 
females with calves move north to the feeding grounds (Calambokidis et 
al., 2014). A few individuals enter into the San Francisco Bay during 
their northward migration.

Bottlenose Dolphins

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

Harbor Porpoise

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

California Sea Lion

    California sea lions breed on the offshore islands of California 
from May through July (Heath and Perrin 2009). During the non-breeding 
season, adult and sub-adult males and juveniles migrate northward along 
the coast, to central and northern California, Oregon, Washington, and 
Vancouver Island (Jefferson et al., 1993). They return south the 
following spring (Lowry and Forney 2005; Heath and Perrin 2009). 
Females and some juveniles tend to

[[Page 42470]]

remain closer to rookeries (Antonelis et al., 1990; Melin et al., 
2008).
    In San Francisco Bay, California sea lions have been observed at 
Angel Island and occupying the docks near Pier 39 which is the largest 
California sea lion haul[hyphen]out in San Francisco Bay. A maximum of 
1,706 sea lions were counted at Pier 39 in 2009. However, since then 
the population has averaged at about 50-300 depending upon the season 
(TMMC 2017). This group of sea lions has decreased in size in recent 
years, coincident with a fluctuating decrease in the herring population 
in the Bay. There are no known breeding sites within San Francisco Bay. 
Their primary breeding site is in the Channel Islands (USACE 2011). The 
sea lions appear at Pier 39 after returning from the Channel Islands at 
the beginning of August (Bauer 1999). No other sea lion haul[hyphen]out 
sites have been identified in the Bay and no pupping has been observed 
at the Pier 39 site or any other site in San Francisco Bay under normal 
conditions (USACE 2011). Although there has been documentation of 
pupping on docks in the Bay, this event was during a domoic acid event. 
The Port does not anticipate that any domoic events will occur during 
the project construction activities.
    The project site is approximately four miles away from Pier 39. 
Although there is little information regarding the foraging behavior of 
the California sea lion in southern San Francisco Bay, they have been 
observed foraging on a regular basis in the shipping channel south of 
Yerba Buena Island.
    Foraging grounds have also been identified for pinnipeds, including 
sea lions, between Yerba Buena Island and Treasure Island, as well as 
off the Tiburon Peninsula (Caltrans, 2006). The California sea lions 
that use the Pier 39 haul[hyphen]out site may be feeding on Pacific 
herring (Clupea harengus), northern anchovy, and other prey in the 
waters of San Francisco Bay (Caltrans, 2013a). In addition to the Pier 
39 haul[hyphen]out, California sea lions haul out on buoys and similar 
structures throughout San Francisco Bay. They mainly are seen swimming 
off the San Francisco and Marin shorelines within San Francisco Bay, 
but may occasionally enter the project area to forage.

Northern Elephant Seal

    Northern elephant seal is common on California coastal mainland and 
island sites, where the species pups, breeds, rests, and molts. The 
largest rookeries are on San Nicolas and San Miguel islands in the 
northern Channel Islands. Near the Bay, elephant seals breed, molt, and 
haul out at A[ntilde]o Nuevo Island, the Farallon Islands, and Point 
Reyes National Seashore.
    Northern elephant seals haul out to give birth and breed from 
December through March. Pups remain onshore or in adjacent shallow 
water through May. Both sexes make two foraging migrations each year: 
One after breeding and the second after molting (Stewart 1989; Stewart 
and DeLong 1995). Adult females migrate to the central North Pacific to 
forage, and males migrate to the Gulf of Alaska to forage (Robinson et 
al. 2012). Pup mortality is high when they make the first trip to sea 
in May, and this period correlates with the time of most strandings. 
Pups of the year return in the late summer and fall, to haul out at 
breeding rookery and small haul out sites, but occasionally they may 
make brief stops in the Bay.
    Generally, only juvenile elephant seals enter the Bay and do not 
remain long. The most recent sighting near the project area was in 
2012, on the beach at Clipper Cove on Treasure Island, when a healthy 
yearling elephant seal hauled out for approximately 1 day. 
Approximately 100 juvenile northern elephant seals strand in or near 
the Bay each year, including individual strandings at Yerba Buena 
Island (YBI) and Treasure Island (less than 10 strandings per year).

Northern Fur Seal

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

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten, 1999; Au and Hastings, 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2018) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 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):
    <bullet> Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz;
    <bullet> Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz;
    <bullet> 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.
    <bullet> Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 Hz to 86 kHz;
    <bullet> 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 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,

[[Page 42471]]

please see NMFS (2018) 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, the gray whale is classified as a 
low-frequency cetacean, the bottlenose dolphin is classified as a mid-
frequency cetacean, and the harbor porpoise is classified as a high-
frequency cetacean.

Potential Effects of Specified Activities on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity may impact marine mammals and 
their habitat. The ``Estimated Take'' section later in this document 
includes a quantitative analysis of the number of individuals that are 
expected to be taken by this activity. The ``Negligible Impact Analysis 
and Determination'' section considers the content of this section, the 
``Estimated Take'' section, and the ``Proposed Mitigation'' section, to 
draw conclusions regarding the likely impacts of these activities on 
the reproductive success or survivorship of individuals and how those 
impacts on individuals are likely to impact marine mammal species or 
stocks.

Description of Sound

    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. 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 one microPascal ([mu]Pa). One pascal is 
the pressure resulting from a force of one newton exerted over an area 
of one square meter (m\2\). 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 [mu]Pa and all airborne sound levels in this document are 
referenced to a pressure of 20 [mu]Pa.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse. Rms is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick 1983). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures.
    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):
    <bullet> 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 
kilohertz (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.
    <bullet> 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.
    <bullet> 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.
    <bullet> 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 source levels (as 
determined by current weather conditions and levels of biological and 
shipping activity) but also on the ability of sound to propagate 
through the environment. In turn, sound propagation is dependent on the 
spatially and temporally varying properties of the water column and sea 
floor, and is frequency-dependent. As a result of the dependence on a 
large number of varying factors, ambient sound levels can be expected 
to vary widely over both coarse and fine spatial and temporal scales. 
Sound levels at a given frequency and location can vary by 10-20 dB 
from day to day (Richardson et al., 1995). The result is that, 
depending on the source type and its intensity, sound from the 
specified activity may be a negligible addition to the local 
environment or could form a distinctive signal that may affect marine 
mammals.

Description of Sound Sources

    In-water construction activities associated with the project would 
include impact pile driving, vibratory

[[Page 42472]]

pile driving, vibratory pile removal, and down the hole drilling. The 
sounds produced by these activities fall into one of two general sound 
types: Impulsive and non-impulsive (defined in the following). The 
distinction between these two sound types is important because they 
have differing potential to cause physical effects, particularly with 
regard to hearing (e.g., Ward 1997 in Southall et al., 2007). Please 
see Southall et al. (2007) for an in-depth discussion of these 
concepts.
    Impulsive 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. Impulsive 
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-impulsive sounds can be tonal, narrowband, or broadband, brief 
or prolonged, and may be either continuous or non-continuous (NIOSH 
1998). Some of these non-impulsive sounds can be transient signals of 
short duration but without the essential properties of impulses (e.g., 
rapid rise time). Examples of non-impulsive sounds include those 
produced by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems. The 
duration of such sounds, as received at a distance, can be greatly 
extended in a highly reverberant environment.
    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

    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 
direct impacts on marine mammals; 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 the Port of San Fancisco'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 the Port of San Francisco'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, 2005). TS can be permanent (PTS), 
in which case the loss of hearing sensitivity is not fully recoverable, 
or temporary (TTS), in which case the animal's hearing threshold would 
recover over time (Southall et al., 2007). Repeated sound exposure that 
leads to TTS could cause PTS. In severe cases of PTS, there can be 
total or partial deafness, while in most cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter 
1985).
    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals--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 found that inducing mild 
TTS (a 6-dB threshold shift) approximates TTS onset (e.g., Southall et 
al., 2007). Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS thresholds for impulsive sounds (such as 
impact pile driving sounds received close to the source) are at least 6 
dB higher than the TTS threshold on a peak-pressure basis and PTS 
cumulative sound exposure level thresholds are 15 to 20 dB higher than 
TTS cumulative sound exposure level thresholds (Southall et al., 2007). 
Given the higher level of sound or longer exposure duration necessary 
to cause PTS as compared with TTS, it is considerably less likely that 
PTS could occur.
    TTS is the mildest form of hearing impairment that can occur during 
exposure to sound (Kryter 1985). While experiencing TTS, the hearing 
threshold rises, and a sound must be at a higher

[[Page 42473]]

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 a time when 
communication is critical for successful mother/calf interactions could 
have more serious impacts.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise, and Yangtze finless porpoise (Neophocoena 
asiaeorientalis) and three species of pinnipeds (northern elephant 
seal, harbor seal, and California sea lion) exposed to a limited number 
of sound sources (i.e., mostly tones and octave-band noise) in 
laboratory settings (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 Finneran (2015).
    In addition to PTS and TTS, there is a potential for 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. These 
impacts can 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). The Port of San 
Francisco'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. These impacts are not anticipated to occur as a 
result of the Port's work and are not discussed further.
    When a live or dead marine mammal swims or floats onto shore and is 
incapable of returning to sea, the event is termed a ``stranding'' (16 
U.S.C. 1421h(3)). Marine mammals are known to strand for a variety of 
reasons, such as infectious agents, biotoxicosis, starvation, fishery 
interaction, ship strike, unusual oceanographic or weather events, 
sound exposure, or combinations of these stressors sustained 
concurrently or in series (e.g., Geraci et al., 1999). However, the 
cause or causes of most strandings are unknown (e.g., Best 1982). 
Combinations of dissimilar stressors may combine to kill an animal or 
dramatically reduce its fitness, even though one exposure without the 
other would not be expected to produce the same outcome (e.g., Sih et 
al., 2004). For further description of stranding events see, e.g., 
Southall et al., 2006; Jepson et al., 2013; Wright et al., 2013.
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-impulsive sound sources (typically seismic airguns or acoustic 
harassment devices) have been varied but often consist of avoidance 
behavior or other behavioral changes suggesting discomfort (Morton and 
Symonds 2002; see also Richardson et al., 1995; Nowacek et al., 2007).
    Available studies show wide variation in response to underwater 
sound; therefore, it is difficult to predict specifically how any given 
sound in a particular instance might affect marine mammals perceiving 
the signal. If a marine mammal does react briefly to an underwater 
sound by changing its behavior or moving a small distance, the impacts 
of the change are unlikely to be significant to the individual, let 
alone the stock or population. However, if a sound source displaces 
marine mammals from an important feeding or breeding area for a 
prolonged period, impacts on individuals and populations could be 
significant (e.g., Lusseau and Bejder 2007; Weilgart 2007; NRC 2005). 
However, there are broad categories of potential response, which we 
describe in greater detail here, that include alteration of dive 
behavior, alteration of foraging behavior, effects to breathing,

[[Page 42474]]

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 occur with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure (e.g., Kastelein et al., 2001, 2005, 2006; Gailey et 
al., 2007).
    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 
(Eubalaena glacialis) have been observed to shift the frequency content 
of their calls upward while reducing the rate of calling in areas of 
increased anthropogenic noise (Parks et al., 2007). In some cases, 
animals may cease sound production during production of aversive 
signals (Bowles et al., 1994).
    Avoidance is the displacement of an individual from an area or 
migration path because 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.
Behavioral Effects of the Port's Activities (Pile Driving and Drilling)
    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). Due to the nature of the 
pile driving sounds

[[Page 42475]]

in the project, behavioral disturbance is the most likely effect from 
the proposed activity. Marine mammals exposed to high intensity sound 
repeatedly or for prolonged periods can experience hearing threshold 
shifts. PTS constitutes injury, but TTS does not (Southall et al., 
2007). Based on the nature of the Port's activity and the anticipated 
effectiveness of the mitigation measures (i.e., use of a bubble 
curtain, wood cushion, and shutdown--discussed in detail below in the 
Proposed Mitigation section), PTS is not anticipated. Therefore, the 
Port is not requesting and NMFS is not proposing to authorize take by 
Level A harassment related to this project.
    The effects of sounds from pile driving, by impact or vibratory 
means, pile removal, and down the hole drilling 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 and drilling 
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 and pile removal 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 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.
    Responses to continuous sound, such as vibratory pile installation 
or down the hole drilling, have not been documented as well as 
responses to impulsive 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, based on more 
general observations of behavioral responses to sound exposure 
(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).
    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 Port's 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 
impulsive sounds occurring for approximately 20 minutes per pile in 
this project. 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 and if it occurred, it 
would be for a short duration. Vibratory pile driving is also 
relatively short-term, with rapid oscillations occurring for 
approximately 20 minutes per pile in this project. 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.
    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 recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with their heads above 
water. Most likely, airborne sound would cause behavioral responses 
similar to those discussed above in relation to underwater sound. For 
instance, anthropogenic sound could cause hauled-out pinnipeds to 
exhibit changes in their normal behavior, such as reduction in 
vocalizations, or cause them to temporarily abandon the area and move 
further from the source. However, these animals would likely previously 
have been `taken' because of exposure to underwater sound above the 
behavioral harassment thresholds, which are in all cases larger than 
those associated with airborne sound. Thus, the behavioral harassment 
of these animals by airborne sound is already accounted for in the 
estimates of potential take from underwater exposure to pile driving 
sounds. Therefore, we do not believe that authorization of additional 
incidental take resulting from airborne sound for pinnipeds is 
warranted, and airborne sound is not discussed further here.
Stress Responses
    An animal's perception of a threat may be sufficient to trigger 
stress responses consisting of some combination of behavioral 
responses, autonomic nervous system responses, neuroendocrine 
responses, or immune responses (e.g., Seyle 1950; Moberg 2000). In many 
cases, an animal's first and sometimes most economical (in terms of 
energetic costs) response is behavioral avoidance of the potential 
stressor. Autonomic nervous system responses to stress typically 
involve changes in heart rate, blood pressure, and gastrointestinal 
activity. These responses have a relatively short duration and may or 
may not have a significant long-term effect on an animal's fitness.

[[Page 42476]]

    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).

Anticipated Effects on Habitat

    The proposed activities at the project area 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 during the 
construction window. The project area is located in an industrial and 
commercial shipping port. 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, drilling, and sediment 
removal in the area. However, other potential impacts to the 
surrounding habitat from physical disturbance are also possible, 
although this will be minimal since construction is occurring in an 
already industrial and commercial shipping area.

In-Water Construction Effects on Potential Prey (Fish)

    Construction activities would produce continuous (i.e., vibratory 
pile driving, drilling) and impulsive (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 
impulsive sounds 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 and pile removal 
activities at the Port's 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 (15 days) 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 the Mission Bay/Central Waterfront 
area of 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 nearby 
vicinity of the MBFL and WTL on San Francisco Bay.
    The duration of the construction activities, including pile driving 
and dredging is relatively short, estimated at 55 days. The 
construction window for pile driving and drilling is a maximum of 15 
days and each day, activities 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 and removal events and the relatively small 
areas being affected, pile driving and pile removal 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,

[[Page 42477]]

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. Based on the nature of the 
activity and the anticipated effectiveness of the mitigation measures 
(i.e., use of a bubble curtain, wood cushion, and shutdown--discussed 
in detail below in the 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.
    Generally speaking, we estimate take by considering: (1) Acoustic 
thresholds above which NMFS believes the best available science 
indicates marine mammals will be behaviorally harassed or incur some 
degree of permanent hearing impairment; (2) the area or volume of water 
that will be ensonified above these levels in a day; (3) the density or 
occurrence of marine mammals within these ensonified areas; and, (4) 
and the number of days of activities. We note that while these basic 
factors can contribute to a basic calculation to provide an initial 
prediction of takes, additional information that can qualitatively 
inform take estimates is also sometimes available (e.g., previous 
monitoring results or average group size). Below, we describe 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 reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2012). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to underwater anthropogenic noise above 
received levels of 120 dB re 1 [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., impact pile driving) sources.
    The Port of San Francisco's proposed activity includes the use of 
continuous (vibratory pile driving, down the hole drilling) and 
impulsive (impact pile driving) sources, and therefore the 120 and 160 
dB re 1 [mu]Pa (rms) thresholds are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Version 2.0) (NMFS, 2018) identifies dual criteria to 
assess auditory injury (Level A harassment) to five different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise from two different types of sources (impulsive or non-impulsive). 
The Port of San Francisco's proposed activity includes the use of 
impulsive (impact pile driving) and non-impulsive (vibratory pile 
driving) sources.
    These thresholds are provided in Table 3 below. The references, 
analysis, and methodology used in the development of the thresholds are 
described in NMFS's 2018 Technical Guidance, which may be accessed at: 
https://www.fisheries.noaa.gov/national/marine-mammal-protection/marine-mammal-acoustic-technical-guidance.
BILLING CODE 3510-22-P

[[Page 42478]]

[GRAPHIC] [TIFF OMITTED] TN22AU18.000

BILLING CODE 3510-22-C

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds, which include source levels and transmission loss 
coefficients.
    Reference sound source levels used by the Port of San Francisco for 
all vibratory and impact piling/removal and drilling activities were 
derived from source level data from construction projects within 
Caltrans (2015) except for two cases noted below where Navy and Alaska 
Department of Transportation sources were used. To determine the 
ensonified areas for both the Level A and Level B harassment zones for 
vibratory piling of the 36-inch, 30-inch, and 16-inch steel piles and 
14-inch steel H piles, the Port of San Francisco used SPLs of 170 dB re 
1 [mu]Pa rms, 170 dB re 1 [mu]Pa rms, 158 dB re 1 [mu]Pa rms, and 158 
dB re 1 [mu]Pa rms, respectively. These were derived from vibratory 
pile driving data of 36-inch (for 36-inch and 30-inch steel piles), 18-
inch (for 16-inch steel piles) and 14-inch (for 14-inch steel H-pile) 
steel piles reported in the values listed in Table 1.2-2 and Table 
1.2.3 of Caltrans (2015), and Table 6-1 of Navy (2017). For vibratory 
pile removal, the Port of San Francisco used an SPL of 155 dB re 1 
[mu]Pa rms. This proxy source level was derived from vibratory pile 
driving data of 12-inch steel pipe piles in Caltrans (2015; Table 1.2-
2). In addition, for down the hole drilling activities used to place 
24-inch octagonal concrete piles, an SPL of 168 dB was used, 
corresponding to the mean SPL reported in Table 72 of the Alaska 
Department of Transportation (2016) hydroacoustic report.
    For impact pile driving, the Port of San Francisco used both SPLs 
and Sound Exposure Levels (SEL) derived from summary source level 
values reported in Caltrans (2015). These source levels were then 
reduced by 7 dB due to the Port of San Francisco's use of a bubble 
curtain. NMFS used a reduction value of 7 dB as it was roughly the 
average sound reduction value derived from sound measurements of piles 
that used bubble curtains within Caltrans (2015). For piling of 36-inch 
steel piles, a source

[[Page 42479]]

level of 183 dB SEL was chosen as a proxy value for modeling Level A 
harassment zones (Caltrans 2015, Table 1.2-1). This source level was 
reduced to 176 dB SEL with the 7 dB reduction. For piling of 20-inch 
concrete piles, a source level of 167 dB SEL was chosen as a proxy 
value for modeling Level A harassment zones (Caltrans 2015, Table 1.5-
4, reported from 24-inch concrete pile measurements at a project in the 
Port of Oakland). This source level was selected as a proxy because of 
the proximity of the Port of Oakland project to the proposed work and 
is more conservative than Caltrans (2015) summary value reported in 
Table 1.2-1. This source level was reduced to 160 dB SEL with the 7 dB 
reduction. In addition, for impact piling of 16-inch steel piles, a 
source level of 158 dB SEL was chosen as a proxy value for modeling 
Level A harassment zones (Joaquin River Project; Caltrans 2015, Table 
1.2-3). This source level was reduced to 151 dB SEL with the 7 dB 
reduction. The stated source levels and their corresponding activity 
are presented in Table 4 below.

                     Table 4--Project Source Levels
------------------------------------------------------------------------
                Activity                  Source level at 10 meters (dB)
------------------------------------------------------------------------
                     Vibratory Pile Driving/Removal
------------------------------------------------------------------------
36-inch steel pile installation.........  170 SPL
30-inch steel pile installation           170 SPL
 (Caisson).
14-inch steel H pile installation.......  158 SPL
Removal of pre-existing piles...........  155 SPL
16-inch steel pile installation.........  158 SPL
------------------------------------------------------------------------
                          Impact Pile Driving *
------------------------------------------------------------------------
36-inch steel pile installation.........  176 SEL/186 SPL
20-inch concrete pile installation......  160 SEL/172 SPL
16-inch steel pile installation.........  151 SEL/177 SPL
------------------------------------------------------------------------
                         Down the Hole Drilling
------------------------------------------------------------------------
24[hyphen]inch Octagonal Concrete         168 SPL
 (drilling of 30-inch hole).
------------------------------------------------------------------------
* The values in the cells reflect a 7dB reduction due to the Port of San
  Francisco's use of a bubble curtain.

Level B Harassment Zones

    The practical spreading model was used by the Port of San Francisco 
to generate the Level B harassment zones for all piling/removal 
activities. Practical spreading is described in full detail below.
    Pile driving and drilling generates underwater noise that can 
potentially result in disturbance to marine mammals in the project 
area. Transmission loss (TL) is the decrease in acoustic intensity as 
an acoustic pressure wave propagates out from a source. TL parameters 
vary with frequency, temperature, sea conditions, current, source and 
receiver depth, water depth, water chemistry, and bottom composition 
and topography. The general formula for underwater TL is:

TL = B * log10 (R1/R2),

Where:

R1 = the distance of the modeled SPL from the driven pile, and
R2 = the distance from the driven pile of the initial measurement.

This formula neglects loss due to scattering and absorption, which is 
assumed to be zero here. The degree to which underwater sound 
propagates away from a sound source is dependent on a variety of 
factors, most notably the water bathymetry and presence or absence of 
reflective or absorptive conditions including in-water structures and 
sediments. Spherical spreading occurs in a perfectly unobstructed 
(free-field) environment not limited by depth or water surface, 
resulting in a 6 dB reduction in sound level for each doubling of 
distance from the source (20 * log[range]). Cylindrical spreading 
occurs in an environment in which sound propagation is bounded by the 
water surface and sea bottom, resulting in a reduction of 3 dB in sound 
level for each doubling of distance from the source (10 * log[range]). 
A practical spreading value of 15 is often used under conditions where 
water increases with depth as the receiver moves away from the 
shoreline, resulting in an expected propagation environment that would 
lie between spherical and cylindrical spreading loss conditions.
    Utilizing the practical spreading loss model, the Port of San 
Francisco determined underwater noise will fall below the behavioral 
effects threshold of 120 dB rms for marine mammals at a maximum radial 
distance of 21,544 meters for vibratory piling and drilling (36 and 30-
inch steel piles; drilling for 24-inch octagonal concrete pile). The 
maximum Level B harassment zone for this activity will therefore be set 
at 21,544 meters. However, previous sound monitoring for other projects 
in San Francisco Bay (i.e. Caltrans 2015; 2016) have shown background 
sound levels in the active portions of the Bay, near the project area, 
to range from 110 to 140 dB rms, with typical background levels in the 
range of 110 to 120 dB rms. This ambient noise may affect the ability 
to distinguish sound from vibratory pile driving in the region (Rodkin, 
2009), but direct applicability of that finding to the Port's work is 
unknown, and therefore no reduction in Level B harassment zone is 
applied. The maximum radial distance of the Level B harassment zone for 
impact pile driving equaled 541.2 meters (impact driving 36-inch steel 
piles). At this radial distance, the entire Level B harassment zone for 
impact piling equaled 0.3699 km\2\. This ensonified area is based on a 
GIS map of the area accounting for structures and landmasses which 
would block sound spreading (Please see Figure 9 of the Application). 
Table 5 below provides all Level B radial distances and their 
corresponding areas for each activity during the Port of San 
Francisco's project. Level B harassment zone areas are calculated using 
a GIS map (See Figure 9 of the Application).

    Table 5--Level B Harassment Zones Calculated Using the Practical
                             Spreading Model
------------------------------------------------------------------------
                                            Calculated        Level B
                                            distance to     harassment
                 Source                       Level B      zone (square
                                             threshold      kilometers
                                             (meters)         km\2\)
------------------------------------------------------------------------
                         Vibratory Pile Driving
------------------------------------------------------------------------
36-inch steel pile installation.........          21,544         47.1608
30-inch steel pile installation.........          21,544         47.1608
16-inch steel pile installation.........          21,544         47.1608
14-inch steel H pile installation.......           3,415          7.6431
Removal of pre-existing concrete and               2,154          3.1511
 wood piles.............................
------------------------------------------------------------------------

[[Page 42480]]

 
                           Impact Pile Driving
------------------------------------------------------------------------
36-inch steel pile installation.........           541.2         0.36993
20-inch concrete pile installation......            63.1        0.006650
16-inch steel pile installation.........             215        0.074044
------------------------------------------------------------------------
                         Down the Hole Drilling
------------------------------------------------------------------------
                                                  21,544         47.1608
------------------------------------------------------------------------

Level A Harassment Zones

    When the NMFS Technical Guidance (2016) was published, in 
recognition of the fact that the ensonified area 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 
overestimate of Level A harassment. However, these tools offer the best 
way to predict appropriate isopleths when more sophisticated 3D 
modeling methods are not available, and NMFS continues to develop ways 
to quantitatively refine these tools, and will qualitatively address 
the output where appropriate. For stationary sources (i.e. pile 
driving), NMFS's 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. Daily 
ensonified areas for Level A harassment are approximated as a semi-
circle because the pile driving and drilling are occurring close to 
shore and the coastline is approximately linear.

                                                                    Table 6--Parameters of Pile Driving and Drilling Activity
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Vibratory pile    Vibratory pile   Vibratory pile   Vibratory pile
                                  Vibratory pile        driver            driver           driver           driver         Impact pile        Impact pile        Impact pile      Drilling (24-
         Equipment type           driver (removal  (installation of   (installation    (installation    (installation    driver (36-inch    driver (20-inch    driver (16-inch    inch octagonal
                                  of concrete and    36-inch steel      of 30-inch       of 16-inch       of 14-inch       steel piles)     concrete piles)      steel piles)     concrete pile)
                                    wood piles)         piles)         steel piles)     steel piles)    steel H piles)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Spreadsheet Tab Used...........  Non-impulsive,    Non-impulsive,    Non-impulsive,   Non-impulsive,   Non-impulsive,   Impulsive, Non-    Impulsive, Non-    Impulsive, Non-    Non-impulsive,
                                  continuous.       continuous.       continuous.      continuous.      continuous.      continuous.        continuous.        continuous.        continuous.
Source Level...................  155 SPL.........  170 SPL.........  170 SPL........  158 SPL........  158 SPL........  176 SEL..........  160 SEL..........  151 SEL..........  168 SPL.
Weighting Factor Adjustment      2.5.............  2.5.............  2.5............  2.5............  2.5............  2................  2................  2................  2.
 (kHz).
(a) Activity duration (hours)    (a) 0.4.........  (a) 0.33........  (a) 0.25.......  (a) .33........  (a) 0.33.......  (b) 150, (c) 4...  (b) 500, (c) 4...  (b) 500, (c) 2...  (a) 6.
 within 24 hours, (b) Number of
 strikes per pile, (c) Number
 of piles per day.
Propagation (xLogR)............  15..............  15..............  15.............  15.............  15.............  15...............  15...............  15...............  15.
Distance of source level         10..............  10..............  10.............  10.............  10.............  10...............  10...............  10...............  10.
 measurement (meters)+.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------


           Table 7--Level A Harassment Zone Isopleth and Ensonified Area for Pile Driving and Drilling
----------------------------------------------------------------------------------------------------------------
                                                                         PTS isopleth (meters)
                                                     -----------------------------------------------------------
                     Source type                         Low-        Mid-        High-
                                                       frequency   frequency   frequency    Phocid      Otariid
                                                       cetaceans   cetaceans   cetaceans   pinnipeds   pinnipeds
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driver (Removal of concrete and wood          1.5         0.1         2.2         0.9         0.1
 piles).............................................
Vibratory Pile Driver (Installation of 36-inch steel        13.1         1.2        19.3         7.9         0.6
 piles).............................................
Vibratory Pile Driver (Installation of 30-inch steel        10.8         1.0        16.0         6.6         0.5
 piles).............................................
Vibratory Pile Driver (Installation of 14-inch steel         2.1         0.2         3.0         1.3         0.1
 H piles)...........................................
Vibratory Pile Driver (Installation of 16-inch steel         2.1         0.2         3.0         1.3         0.1
 H piles)...........................................
Impact Pile Driver (36-inch steel piles)............       242.6         8.6       288.9       129.8         9.5
Impact Pile Driver (20-inch concrete piles).........        46.4         1.7        55.3        24.8         1.8
Impact Pile Driver (16-inch steel piles)............         7.3         0.3         8.8         3.9         0.3
Drilling (24-inch octagonal concrete pile)..........         6.3         0.4         5.5         3.4         0.2
----------------------------------------------------------------------------------------------------------------
                                            Daily ensonified area (m)
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driver (Removal of concrete and wood          3.5        0.02         7.6         1.3        0.02
 piles).............................................
Vibratory Pile Driver (Installation of 36-inch steel         270         2.3         585          98         0.6
 piles).............................................
Vibratory Pile Driver (Installation of 30-inch steel         183         1.6         402          68         0.4
 piles).............................................

[[Page 42481]]

 
Vibratory Pile Driver (Installation of 14-inch steel         6.9        0.06          14         2.7        0.02
 H piles)...........................................
Vibratory Pile Driver (Installation of 16-inch steel         6.9        0.06          14         2.7        0.02
 H piles)...........................................
Impact Pile Driver (36-inch steel piles)............       92450         120      131100       26460         140
Impact Pile Driver (20-inch concrete piles).........        3380         4.5        4800         966         5.1
Impact Pile Driver (16-inch steel piles)............          84         0.1         120          24         0.1
Drilling (24-inch octagonal concrete pile)..........          62         0.3          48          18        0.06
----------------------------------------------------------------------------------------------------------------

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.
    No systematic line transect surveys of marine mammals have been 
performed in San Francisco Bay. Therefore, the in-water densities of 
harbor seals, California sea lions, and harbor porpoises were 
calculated based on 17 years of observations during monitoring for the 
San Francisco Bay-Oakland Bay Bridge (SFOBB) construction and 
demolition project (Caltrans 2018). Care was taken to eliminate 
multiple observations of the same animal, although this can be 
difficult and is likely that the same individual may have been counted 
multiple times on the same day. The amount of monitoring performed per 
year varied, depending on the frequency and duration of construction 
activities with the potential to affect marine mammals. During the 257 
days of monitoring from 2000 through 2017 (including 15 days of 
baseline monitoring in 2003), 1,029 harbor seals, 83 California sea 
lions, and 24 harbor porpoises were observed in waters in the project 
vicinity in total. In 2015, 2016, and 2017, the number of harbor seals 
in the project area increased significantly. In 2017, the number of 
harbor porpoise in the project area also increased significantly. 
Therefore, a harbor seal density estimate was calculated using the 
2015-2017 data, and a harbor porpoise density estimate was calculated 
using the 2017 data, which may better reflect the current use of the 
project area by these animals. These observations included data from 
baseline, pre-, during, and post-pile driving, mechanical dismantling, 
on-shore blasting, and off-shore implosion activities.
    Insufficient sighting data exist to estimate the density of 
bottlenose dolphins. However, a single bottlenose dolphin has been 
observed regularly near the project site. One individual was documented 
regularly, through photo ID, over several months off the coast of the 
former Alameda Air Station (Perlman 2017).
    Insufficient sighting data exist to estimate elephant seal 
densities in the Bay. Generally, only juvenile elephant seals enter the 
Bay and do not remain long. The most recent sighting near the project 
area was in 2012, on the beach at Clipper Cove on Treasure Island, when 
a healthy yearling elephant seal hauled out for approximately 1 day. 
Approximately 100 juvenile northern elephant seals strand in or near 
the Bay each year, including individual strandings at YBI and Treasure 
Island (less than 10 strandings per year).
    In addition, insufficient sighting data exist to estimate northern 
fur seal and gray whale densities in the Bay. Only two to four northern 
fur seals strand in the Bay each year, and they are unlikely to occur 
in the project area. Also, during the 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.
    Numbers used for density calculations are shown in Table 8. These 
numbers were calculated from observations in nearby waters of the San 
Francisco Bay during San Francisco-Oakland Bay Bridge construction 
conducted by Caltrans (Caltrans 2018). These observations occurred from 
2000 to 2017 in a 2 km\2\ monitoring zone for California sea lions, 
from 2015-2017 in a 2 km\2\ monitoring zone for harbor seals, and in 
2017 in a 15 km\2\ zone for harbor porpoise. In the cases where 
densities were refined to capture a narrower range of years to be 
conservative, bold densities were used for take calculations.

             Table 8--Estimated In-Water Density of Marine Mammal Species in San Francisco Bay Area
                                                 [Caltrans 2017]
----------------------------------------------------------------------------------------------------------------
                                            Area of                        Number of
           Species observed               monitoring        Days of         animals       Density animals/km\2\
                                         zone (km\2\)     monitoring       observed
----------------------------------------------------------------------------------------------------------------
Harbor Seals 2000-2017................               2             257            1029  2.002.
Harbor Seals 2015-2017................               2              47             372  3.957.
California Sea Lions 2000-2017........               2             257              83  0.161.
Bottlenose Dolphins 2017..............               2               6               2  Insufficient sighting
                                                                                         data exists to estimate
                                                                                         density.
Harbor Porpoise 2000-2017.............               3             257              24  0.031.

[[Page 42482]]

 
Harbor Porpoise 2017..................              15               6              15  0.167.
Elephant Seal 2000-2017...............               2             257               0  Insufficient sighting
                                                                                         data exists to estimate
                                                                                         density.
Northern Fur Seal 2000-2017...........               2             257               0  Insufficient sighting
                                                                                         data exists to estimate
                                                                                         density.
Gray Whale 2000-2017..................               2             257               0  Insufficient sighting
                                                                                         data exists to estimate
                                                                                         density.
----------------------------------------------------------------------------------------------------------------
Notes:
Densities for Pacific harbor seals, California sea lions, and harbor porpoises are based on monitoring for the
  east span of the SFOBB from 2000 to 2017.
A second set of Pacific harbor seal densities were calculated from the increase in sightings recorded from 2015
  to 2017.
A second set of harbor porpoise densities were calculated for the increase in sightings that were recorded in
  2017.
Bold densities were used for take calculations.
Sources: CalTrans 2001, 2004b, 2013b, 2013c, 2014, 2015b, 2016, 2017; Perlman 2017.

    For species without enough sightings to construct a density 
estimate, we used information based on group size and frequency of 
sightings from previous years of work to inform the number of animals 
estimated to be taken, which is detailed in the Take Estimation section 
below.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    When density data was available, Level B take for the project was 
calculated by multiplying the density times the largest Level B 
harassment zone (km\2\) times the number of construction days. Since 
density data was only available for harbor seals, harbor porpoises, and 
California sea lions, these were the only species whose take was 
calculated used this methodology. Table 9 shows the number of take 
calculated for species with density and without density estimates. For 
species without density information, information on average group size 
of the species was used. This is discussed below Table 9.

                           Table 9--Take Estimates as a Percentage of Stock Abundance
----------------------------------------------------------------------------------------------------------------
                                                      Level B
                                Density animals/    harassment     Construction   Proposed Level   Percentage of
            Species                   km\2\        zone (km\2\)      days \2\         B take           stock
                                                        \1\
----------------------------------------------------------------------------------------------------------------
Harbor Seal...................  3.957...........         47.1608              15            2928             9.5
California Sea Lions..........  0.161...........         47.1608              15             120           0.040
Harbor Porpoise...............  0.167...........         47.1608              15             124             1.3
Northern Elephant Seal........  Insufficient             47.1608              15               1          0.0006
                                 sighting data
                                 exists to
                                 estimate
                                 density.
Northern Fur Seal.............  Insufficient             47.1608              15               1          0.0002
                                 sighting data
                                 exists to
                                 estimate
                                 density.
Gray Whale....................  Insufficient             47.1608              15               3           0.014
                                 sighting data
                                 exists to
                                 estimate
                                 density.
Bottlenose Dolphin............  Insufficient             47.1608              15              15             3.3
                                 sighting data
                                 exists to
                                 estimate
                                 density.
----------------------------------------------------------------------------------------------------------------
\1\ Represents area of largest Level B zone during pile driving/removal and drilling activities.
\2\ Total construction days for pile driving/removal and drilling.

Gray Whale
    Gray whales occasionally enter San Francisco Bay during their 
northward migration period of February and March. Pile driving and 
drilling are 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 conservatively estimated that, at most, 3 gray whales, or one 
average sized group, may be exposed to Level B harassment during the 15 
days of pile driving/drilling.
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) and one individual has 
been observed near Alameda (GGCR 2016). Observations of bottlenose 
dolphins are primarily west of Treasure Island and concentrated along 
the nearshore areas of San Francisco south to Redwood City (Caltrans 
2018). Bottlenose dolphins rarely occur in San Francisco Bay, but given 
the size of the Level B harassment zone NMFS is proposing to authorize 
take of 15 bottlenose dolphins by level B harassment.

[[Page 42483]]

Northern Fur Seal
    Observations of northern fur seals are too few to establish a 
density for this species in San Francisco Bay. The Marine Mammal Center 
(TMMC) reported only two to four northern fur seal strandings in the 
Bay in 2015 and 2016 (in Marin, San Francisco, and Santa Clara 
counties) (TMMC 2017). To account for the possible rare presence of the 
species in the action area, NMFS proposes to authorize one level B take 
of northern fur seal.
Northern Elephant Seal
    Elephant seals breed between December and March and have been 
rarely cited in San Francisco Bay. It is anticipated that if an 
elephant seal is encountered at all during pile driving or drilling it 
would be a juvenile. To account for the possible rare presence of the 
species in the action area, NMFS proposed to authorize one level B take 
of elephant seal.
Level A Harassment
    High frequency cetaceans (including harbor porpoise) have the 
largest Level A harassment zone resulting from this project as shown in 
Table 7. Estimated take by Level A harassment for harbor porpoise, 
based on density reported in Table 8 and the Level A harassment zone, 
is less than one individual (Density * Days * Ensonified Area). Given 
the required mitigation measures, including shutdown zones which exceed 
the Level A harassment zone, NMFS proposes no authorization of Level A 
harassment for harbor porpoise or any marine mammal.

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.
    In addition to the specific measures described later in this 
section, the Port must conduct briefings for construction supervisors 
and crews, the monitoring team, and Port staff prior to the start of 
all pile driving activity, and when new personnel join the work, in 
order to explain responsibilities, communication procedures, the marine 
mammal monitoring protocol, and operational procedures.

Timing Restrictions

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

Sound Attenuation

    Sound attenuation methods will be implemented for the duration of 
impact pile driving to install 36[hyphen]inch and 16[hyphen]inch steel 
and 20[hyphen]inch concrete piles (i.e., cushion block, bubble curtain, 
sleeve etc.) and shall implement the following bubble curtain 
performance standards:
    <bullet> The bubble curtain must distribute air bubbles around 100 
percent of the piling perimeter for the full depth of the water column.
    <bullet> 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.
    <bullet> The selected contractor will ensure that personnel are 
trained in the proper balancing of air flow to the bubblers and shall 
require that construction contractors submit an inspection/performance 
report for approval by the Port within 72 hours following the 
performance test. Corrections to the attenuation device to meet the 
performance standards shall occur prior to impact driving.

Shutdown Zone for In-Water Heavy Machinery Work

    For in-water heavy machinery work (using, e.g., standard barges, 
tug boats, barge-mounted excavators, or clamshell equipment used to 
place or remove material), a minimum 10 meter shutdown zone shall be 
implemented. If a marine mammal comes within 10 meters of such 
operations, operations shall cease and vessels shall reduce speed to 
the minimum level required to maintain steerage and safe working 
conditions. This type of work could include (but is not limited to) the 
following activities: (1) Vibratory pile driving; (2) movement of the 
barge to the pile location; (3) positioning of the pile on the 
substrate via a crane (i.e., stabbing the pile); or (4) removal of the 
pile from the water column/substrate via a crane (i.e., deadpull).

Additional Shutdown Zones

    For all pile driving/removal and drilling activities, The Port of 
San Francisco will establish a shutdown zone for a marine mammal 
species that is greater than its corresponding Level A harassment zone. 
The purpose of a shutdown zone is generally to define an area within 
which shutdown of the activity would occur upon sighting of a marine 
mammal (or in anticipation of an animal entering the defined area). The 
shutdown zones for each of the pile driving and drilling activities are 
listed below in Table 10.

[[Page 42484]]



                                            Table 10--Shutdown Zones
----------------------------------------------------------------------------------------------------------------
                                                              Shutdown zones (meters)
                                 -------------------------------------------------------------------------------
                                                                       High-
                                  Low- frequency  Mid- frequency     frequency
             Source                  cetaceans       cetaceans       cetaceans
                                     (humpback       (Pacific-        (Dall's     Phocid (harbor   Otariid (sea
                                   whale, minke     white sided      porpoise,         seal)           lion)
                                      whale)         dolphin)         harbor
                                                                     porpoise)
----------------------------------------------------------------------------------------------------------------
                                       In-Water Construction Activities *
----------------------------------------------------------------------------------------------------------------
In Water Heavy Construction                   10              10              10              10              10
 (i.e., Barge movements, pile
 positioning, deadpulling, and
 sound attenuation).............
----------------------------------------------------------------------------------------------------------------
                                             Vibratory Pile Driving
----------------------------------------------------------------------------------------------------------------
Vibratory Pile Driver (Removal                10              10              10              10              10
 of concrete and wood piles)....
Vibratory Pile Driver                         10              10              10              10              10
 (Installation of 14-inch steel
 H piles).......................
Vibratory Pile Driver                         10              10              10              10              10
 (Installation of 16-inch steel
 H piles).......................
Vibratory Pile Driver                         25              10              25              10              10
 (Installation of 30-inch steel
 piles).........................
Vibratory Pile Driver                         25              10              25              10              10
 (Installation of 36-inch steel
 piles).........................
----------------------------------------------------------------------------------------------------------------
                                               Impact Pile Driving
----------------------------------------------------------------------------------------------------------------
Impact Pile Driver (16-inch                  125              10             150              75              10
 steel piles)...................
Impact Pile Driver (20-inch                   75              10              75              30              10
 concrete piles)................
Impact Pile Driver (36-inch                  250              25             300             150              25
 steel piles)...................
----------------------------------------------------------------------------------------------------------------
                                                    Drilling
----------------------------------------------------------------------------------------------------------------
24-inch concrete pile (1 pile)                10              10              10              10              10
 (3 hours per day on 1 day).....
----------------------------------------------------------------------------------------------------------------

Monitoring Zones

    The Port of San Francisco will establish and observe a monitoring 
zone. The monitoring zones for this project will differ based on 
activity. For vibratory pile driving and down the hole drilling, it may 
not be possible to observe the entire Level B harassment zones (areas 
where SPLs are equal to or exceed 120 dB rms) due to their size. The 
Port is expected to monitor and record observations in the largest 
reasonable portion of this Level B harassment zone based on the number 
of observers and visibility, but conditions may require efforts to be 
focused in a smaller monitoring zone. For impact pile driving, the 
monitoring zones are areas where SPLs are equal to or exceed 160 dB 
rms. For vibratory pile driving/drilling and impact pile driving the 
Level B Harassment zones are presented in Table 11 below. For the 
vibratory pile driving and drilling activities, it is noted that Level 
B harassment zone radius and area will not necessarily equal the 
monitoring zone. These zones provide utility for monitoring conducted 
for mitigation purposes (i.e., shutdown zone monitoring) by 
establishing monitoring protocols for areas adjacent to the shutdown 
zones. Monitoring of disturbance zones enables observers to be aware of 
and communicate the presence of marine mammals in the project area, but 
outside the shutdown zone, and thus prepare for potential shutdowns of 
activity. However, the primary purpose of disturbance zone monitoring 
is for documenting instances of Level B harassment; disturbance zone 
monitoring is discussed in detail later (see Monitoring and Reporting).

                       Table 11--Monitoring Zones
------------------------------------------------------------------------
                                              Radial
                                            distance to       Level B
                 Source                       Level B       harassment
                                             threshold     zone (km\2\)
                                             (meters)
------------------------------------------------------------------------
                         Vibratory Pile Driving
------------------------------------------------------------------------
36-inch steel pile installation.........        * 21,544       * 47.1608
30-inch steel pile installation.........        * 21,544       * 47.1608
16-inch steel pile installation.........        * 21,544       * 47.1608
14-inch steel H pile installation.......         * 3,415        * 7.6431
Removal of pre-existing concrete and            * 21,544       * 47.1608
 wood piles.............................
------------------------------------------------------------------------
                           Impact Pile Driving
------------------------------------------------------------------------
36-inch steel pile installation.........           541.2          0.3699
20-inch concrete pile installation......            63.1        0.006650

[[Page 42485]]

 
16-inch steel pile installation.........             215        0.074044
------------------------------------------------------------------------
                         Down the Hole Drilling
------------------------------------------------------------------------
                                                * 21,544       * 47.1608
------------------------------------------------------------------------
* The monitored radius and area of the Level B harassment zone may vary
  based on visibility.

Non-Authorized Take Prohibited

    If a species enters or approaches the Level B harassment zone and 
that species is either not authorized for take or its authorized takes 
are met, pile driving, pile removal, and drilling activities must shut 
down immediately using delay and shut-down procedures. Activities must 
not resume until the animal has been confirmed to have left the area or 
an observation time period of 15 minutes has elapsed.

Soft Start

    The use of a soft-start procedure is believed to provide additional 
protection to marine mammals by providing warning and/or giving marine 
mammals a chance to leave the area prior to the impact hammer operating 
at full capacity. For impact pile driving, contractors will be required 
to provide an initial set of strikes from the hammer at 40 percent 
energy, each strike followed by no less than a 30-second waiting 
period. This procedure will be conducted a total of three times before 
impact pile driving begins. This soft start procedure must be 
implemented at the start of a day's impact pile driving and at any time 
following cessation of impact driving of 30 minutes or greater. Soft 
start is not required during vibratory pile driving/removal or drilling 
activities.

Pre-Activity Monitoring

    Prior to the start of daily in-water construction activity, or 
whenever a break in pile driving or drilling of 30 minutes or longer 
occurs, the observer will observe the shutdown and monitoring zones for 
a period of 30 minutes. The shutdown zone will be cleared when a marine 
mammal has not been observed within the zone for that 30-minute period. 
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 is observed within the shutdown zone, a soft-start cannot 
proceed until the animal has left the zone or has not been observed for 
15 minutes. If the monitoring zone has been observed for 30 minutes and 
non-permitted species are not present within the zone, soft start 
procedures can commence and work can continue even if visibility 
becomes impaired within the monitoring zone. When a marine mammal 
permitted for Level B take is present in the monitoring zone, pile 
driving, pile removal, and drilling activities may begin and Level B 
take will be recorded. As stated above, if the entire Level B zone is 
not visible at the start of construction, piling or drilling activities 
can begin. If work ceases for more than 30 minutes, the pre-activity 
monitoring of both the monitoring zone and shutdown zone will commence.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, Section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth, requirements pertaining to 
the monitoring and reporting of such taking. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
authorizations must include the suggested means of accomplishing the 
necessary monitoring and reporting that will result in increased 
knowledge of the species and of the level of taking or impacts on 
populations of marine mammals that are expected to be present in the 
proposed action area. Effective reporting is critical both to 
compliance as well as ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
    <bullet> Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density);
    <bullet> Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
    <bullet> Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
    <bullet> How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
populations, species, or stocks;
    <bullet> Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
    <bullet> Mitigation and monitoring effectiveness.

Hydroacoustic Monitoring

    The Port recognizes in their application the need to implement a 
sound monitoring plan (SMP) as required by the Regional NMFS and U.S. 
Army Corps of Engineers programmatic review for pile driving activities 
in San Francisco Bay. The Port indicates that this SMP will recommend 
sound monitoring stations at 10 m, 100 m, and 300 m to monitor ambient 
noise conditions in the area. NMFS feels that ambient noise 
measurements are highly specific to the time and place they were taken, 
and therefore might have limited

[[Page 42486]]

use to future projects. However, there are few source level 
measurements for down the hole drilling activities, as shown by the use 
of Alaska DOT proxy data in this IHA. NMFS feels that rigorous 
hydroacoustic monitoring of source level for the down the hole drilling 
activity will be more beneficial for future projects in this region and 
others. While NMFS is not requiring these source level measurements, if 
the Port were already planning to conduct measurements, we recommend 
focusing on source level verification and could offer guidance on its 
implementation.

Visual Monitoring

    Monitoring would be conducted 30 minutes before, during, and 30 
minutes after all pile driving/removal and drilling activities. In 
addition, observers shall record all incidents of marine mammal 
occurrence, regardless of distance from activity, and shall document 
any behavioral reactions in concert with distance from piles being 
driven, removed, or pile holes being drilled. Pile driving and drilling 
activities include the time to install, remove, or drill a hole for a 
single pile or series of piles, as long as the time elapsed between 
uses of the pile driving equipment is no more than thirty minutes.
    Monitoring will be conducted by NMFS approved Protected Species 
Observers (PSOs). There will be at least two PSOs, but this number 
could be higher, depending on the type of pile driving/drilling and 
size of pile, which determines the size of the harassment zones. At 
least two land-based PSOs will monitor during all pile driving/removal 
and drilling activities.
    PSOs shall scan the waters using binoculars, and/or spotting 
scopes, and shall use a handheld GPS or range-finder device to verify 
the distance to each sighting from the project site. All PSOs shall be 
trained in marine mammal identification and behaviors and are required 
to have no other project-related tasks while conducting monitoring. In 
addition, monitoring shall be conducted by qualified observers, who 
shall be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator. Qualified observers 
are trained and/or experienced professionals, with the following 
minimum qualifications:
    i. At least one PSO must have prior experience working as a marine 
mammal observer during construction activities;
    <bullet> Independent observers (i.e., not construction personnel);
    ii. Other PSOs may substitute education (degree in biological 
science or related field) or training for experience;
    iii. Where a team of three or more PSOs are required, a lead 
observer or monitoring coordinator shall be designated. The lead 
observer must have prior experience working as a marine mammal observer 
during construction;
    iv. The Port of San Francisco shall submit PSO CVs for approval by 
NMFS; The Port of San Francisco shall ensure that observers have the 
following additional qualifications:
    <bullet> Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
    <bullet> Ability to conduct field observations and collect data 
according to assigned protocols;
    <bullet> Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
    <bullet> 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;
    <bullet> Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary; and
    <bullet> Sufficient training, orientation, or experience with the 
construction operations to provide for personal safety during 
observations.
    The Port of San Francisco shall submit a draft report to NMFS not 
later than 90 days following the end of construction activities. The 
Port of San Francisco shall provide a final report within 30 days 
following resolution of NMFS' comments on the draft report. Reports 
shall contain, at minimum, the following:
    <bullet> Date and time that monitored activity begins and ends for 
each day conducted (monitoring period);
    <bullet> Construction activities occurring during each daily 
observation period, including how many and what type of piles driven;
    <bullet> Deviation from initial proposal in pile numbers, pile 
types, average driving times, etc.;
    <bullet> Weather parameters in each monitoring period (e.g., wind 
speed, percent cloud cover, visibility);
    <bullet> Water conditions in each monitoring period (e.g., sea 
state, tide state);
    <bullet> Extrapolated estimates of the total observed Level B 
harassment takes based on the percentage of the Level B harassment zone 
that was not visible or was not monitored
    <bullet> For each marine mammal sighting:
    [cir] Species, numbers, and, if possible, sex and age class of 
marine mammals;
    [cir] Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity;
    [cir] Location and distance from pile driving activities to marine 
mammals and distance from the marine mammals to the observation point;
    [cir] Estimated amount of time that the animals remained in the 
Level B harassment zone;
    [cir] Description of implementation of mitigation measures within 
each monitoring period (e.g., shutdown or delay);
    [cir] Other human activity in the area within each monitoring 
period; and
    [cir] A summary of the following:
    [ssquf] Total number of individuals of each species detected within 
the monitoring zone, and estimated as taken if correction factor 
appropriate;
    [ssquf] Total number of individuals of each species detected within 
the Level A harassment zone and the average amount of time that they 
remained in that zone; and
    [ssquf] Daily average number of individuals of each species 
(differentiated by month as appropriate) detected within the monitoring 
zone, and estimated as taken, if appropriate.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity,

[[Page 42487]]

duration), the context of any responses (e.g., critical reproductive 
time or location, migration), as well as effects on habitat, and the 
likely effectiveness of the mitigation. We also assess the number, 
intensity, and context of estimated takes by evaluating this 
information relative to population status. Consistent with the 1989 
preamble for NMFS's implementing regulations (54 FR 40338; September 
29, 1989), the impacts from other past and ongoing anthropogenic 
activities are incorporated into this analysis via their impacts on the 
environmental baseline (e.g., as reflected in the regulatory status of 
the species, population size and growth rate where known, ongoing 
sources of human-caused mortality, or ambient noise levels).
    As stated in the mitigation section, bubble curtains will be used 
and shutdown zones that encompass the area in which Level A harassment 
might be expected to occur will be implemented. As a result, no Level A 
take is expected nor authorized for this activity. Exposures to 
elevated sound levels produced during pile driving activities may cause 
behavioral responses by an animal, but they are expected to be mild and 
temporary. Effects on individuals that are taken by Level B harassment, 
on the basis of reports in the literature as well as monitoring from 
other similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff, 
2006; Lerma, 2014). Most likely, individuals will simply move away from 
the sound source and be temporarily displaced from the areas of pile 
driving, although even this reaction has been observed primarily only 
in association with impact pile driving. These reactions and behavioral 
changes are expected to subside quickly when the exposures cease. 
Within the project area, there are no critical habitats or other 
biologically important areas (Calambokidis et al., 2015). The area is 
an active commercial port, and while harbor seals, California sea 
lions, and other marine mammals may be present, the area is not an 
established rookery or breeding ground for local populations.
    During all impact driving, implementation of soft start procedures, 
the use of a bubble curtain, and monitoring of established shutdown 
zones will be required. Given sufficient notice through use of soft 
start (for impact driving), marine mammals are expected to move away 
from an irritating sound source prior to it becoming potentially 
injurious. In addition, PSOs will be stationed within the action area 
whenever pile driving/removal and drilling operations are underway. 
Depending on the activity, The Port of San Francisco will employ the 
use of at least two PSOs to ensure all monitoring and shutdown zones 
are properly observed.
    Although the Mission Bay Ferry and Water Taxi Landing Project would 
have some permanent removal of habitat available to marine mammals, the 
area lost would negligible. Construction of the MBFL and WTL structures 
and dredging for the project will result in the disturbance of up to 
approximately 8.4 acres of predominantly fine[hyphen]grained sediment 
and the associated benthic infaunal community. Total habitat disturbed 
from the project activities is estimated at 0.000071 percent of the 
total South San Francisco Bay subtidal habitat available (NOAA 2007). 
This is a relatively small fraction of area relative to the total 
available habitat for foraging and transit for marine mammals. In 
addition, to minimize impacts, in[hyphen]water construction will be 
limited to locally established environmental work windows between June 
and November.
    Overall, impacts to marine mammals and prey species due to the 
Mission Bay Ferry and Water Taxi Landing Project are expected to be 
minor and temporary. The area impacted by the project is very small 
compared to the available habitat around San Francisco Bay. The most 
likely impact to prey will be temporary behavioral avoidance of the 
immediate area. During pile driving and drilling, it is expected that 
fish and marine mammals would temporarily move to nearby locations and 
return to the area following cessation of in-water construction 
activities. Therefore, indirect effects on marine mammal prey during 
the construction are not expected to be substantial.
    In summary and as described above, the following factors primarily 
support our determination that the impacts resulting from this activity 
are not expected to adversely affect the species or stock through 
effects on annual rates of recruitment or survival:
    <bullet> Mortality is not anticipated or authorized;
    <bullet> Minimal impacts to marine mammal habitat are expected;
    <bullet> Bubble curtain and other sound attenuating devices are 
used during impact pile driving will lessen the amount of behavioral 
disturbance and contribute to the alleviation of the likelihood of 
injury;
    <bullet> Impacts are not occurring in rookeries, or known areas or 
features of special significance for foraging or reproduction in the 
project area;
    <bullet> Anticipated incidents of Level B harassment consist of, at 
worst, temporary modifications in behavior; and
    <bullet> Required mitigation measures (i.e. shutdown zones) are 
expected to be effective in reducing the effects of the specified 
activity.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the monitoring and mitigation 
measures, NMFS preliminarily finds that the total marine mammal take 
from the activity will have a negligible impact on all affected marine 
mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities.
    Take for all species authorized except harbor seal is less than 
five percent of their respective stock abundance. For harbor seal, the 
authorized take is less than 10 percent of the stock abundance. Based 
on this and the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

Unmitigable Adverse Impact Analysis and Determination

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

[[Page 42488]]

Endangered Species Act (ESA)

    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 the Port of San Francisco for conducting pile driving/
removal and drilling in San Francisco Bay from June 1, 2019 to May 31, 
2020, provided the previously mentioned mitigation, monitoring, and 
reporting requirements are incorporated. This section contains a draft 
of the IHA itself. The wording contained in this section is proposed 
for inclusion in the IHA (if issued).
    1. This Incidental Harassment Authorization (IHA) is valid from 
June 1, 2019, to May 31, 2020.
    2. This IHA is valid only for impact pile driving, vibratory pile 
driving, vibratory pile removal, and drilling activities associated 
with the construction of the Mission Bay Ferry and Water Taxi Landing 
Project in San Francisco Bay, California
    3. General Conditions
    (a) A copy of this IHA must be in the possession of the Port of San 
Francisco, its designees, and work crew personnel operating under the 
authority of this IHA;
    (b) The species authorized for taking are gray whale (Eschrichtius 
robustus), bottlenose dolphin (Tursiops truncatus), harbor porpoise 
(Phocoena phocoena), California sea lion (Zalophus californianus), 
northern fur seal (Callorhinus ursinus), Pacific harbor seal (Phoca 
vitulina richardii), and northern elephant seal (Mirounga 
angustirostris);
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b). See Table 9 for numbers of take 
authorized;
    (d) The taking by 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) The Port of San Francisco must conduct briefings between 
construction supervisors and crews and marine mammal monitoring team 
prior to the start of all pile driving, pile removal, and drilling, and 
when new personnel join the work, in order to explain responsibilities, 
communication procedures, marine mammal monitoring protocol, and 
operational procedures; and
    (f) Pile driving and drilling activities authorized under this IHA 
may only occur during daylight hours.
    4. Mitigation Measures
    The holder of this Authorization is required to implement the 
following mitigation measures:
    (a) For all pile driving/removal, drilling, and in-water heavy 
machinery work, the Port of San Francisco must implement a shutdown 
zone around the pile or work zone. If a marine mammal comes within or 
approaches the shutdown zone, such operations must cease. See Table 10 
for minimum radial distances required for shutdown zones;
    (b) After a shutdown occurs, impact pile driving, vibratory piling 
driving/removal, and/or drilling can only begin after the animal is 
observed leaving the shutdown zone or has not been observed for 15 
minutes;
    (c) The Port of San Francisco must use sound attenuation devices 
(i.e. cushion block, and bubble curtain) during all impact pile driving 
and a caisson sleeve during drilling. The Port of San Francisco must 
implement the following bubble curtain performance standards:
    (1) The bubble curtain must distribute air bubbles around 100 
percent of the piling perimeter for the full depth of the water column;
    (2) The lowest bubble ring must be in contact with the mudline for 
the full circumference of the ring, and the weights attached to the 
bottom ring must ensure 100 percent mudline contact. No parts of the 
ring or other objects shall prevent full mudline contact; and
    (3) The selected contractor must ensure that personnel are trained 
in the proper balancing of air flow to the bubblers and must require 
that construction contractors submit an inspection/performance report 
for approval by the Port within 72 hours following the performance 
test. Corrections to the attenuation device to meet the performance 
standards must occur prior to impact driving;
    (d) The Port of San Francisco must use a soft-start procedure for 
impact pile driving. During a soft start, The Port of San Francisco is 
required to provide an initial set of three strikes from the impact 
hammer at 40 percent energy, followed by a 30-second waiting period, 
then two subsequent 3-strike sets. This soft-start must be applied 
prior to beginning pile driving activities each day or when impact pile 
driving hammers have been idle for more than 30 minutes;
    (e) If a species enters or approaches the Level B harassment zone 
and that species is either not authorized for take or its authorized 
takes are met, pile driving and removal activities must shut down 
immediately using delay and shut-down procedures; and
    (f) The Port of San Francisco must establish monitoring locations 
as described below.
    5. Monitoring
    The holder of this Authorization is required to conduct marine 
mammal monitoring during all pile driving/removal and drilling 
activities. Monitoring and reporting must be conducted in accordance 
with the Monitoring Plan as described below.
    (a) The Port of San Francisco must monitor the Level B harassment 
zones and shutdown zones shown in Tables 10 and 11 during all pile 
driving/removal and drilling activities. Monitoring efforts in the 
Level B harassment zone can be concentrated in a subset of the zone if 
it is not feasible to observe the entire zone.
    (b) If waters exceed a sea-state which restricts the observers' 
ability to make observations within the marine mammal shutdown zone, 
pile installation/removal and drilling must cease. Pile driving and/or 
drilling must not be initiated or continue until the entire largest 
shutdown zone for the activity is visible.
    (c) Prior to the start of daily in-water construction activity, or 
whenever a break in pile driving/removal and/or drilling of 30 minutes 
or longer occurs, the PSOs must observe the shutdown and monitoring 
zones for a period of 30 minutes before construction activities can 
begin.
    (d) If the shutdown zones have been observed to be clear of marine 
mammals for 30 minutes, in-water construction can commence and work can 
continue even if visibility becomes impaired within the Level B 
harassment zone.
    (e) Monitoring must be conducted by qualified PSOs, with minimum 
qualifications as described previously in the Monitoring and Reporting 
section of the proposed Federal Notice. PSO requirements include:
    (i) At least two PSOs must be on site to actively observe the 
shutdown and disturbance zones during all pile driving, removal, and 
drilling;
    (ii) Observers must use their naked eye with the aid of binoculars, 
and/or a spotting scope during all pile driving and extraction 
activities;
    (iii) All PSOs must be positioned in the best vantage point to have 
an unobstructed view of all water within the shutdown zone and as much 
of the Level B harassment zone as possible for pile driving/removal 
and/or drilling;
    (iv) Observers must be independent (i.e., not construction 
personnel);

[[Page 42489]]

    (v) At least one PSO must have prior experience working as a marine 
mammal observer during construction activities;
    (vi) (Other PSOs may substitute education (degree in biological 
science or related field) or training for experience;
    (vii) Where a team of three or more PSOs are required, a lead 
observer or monitoring coordinator shall be designated. The lead 
observer must have prior experience working as a marine mammal observer 
during construction;
    (viii) The Port of San Francisco shall submit PSO CVs for approval 
by NMFS;
    (f) Marine mammal location must be determined using a rangefinder 
and a GPS or compass;
    (g) Post-construction monitoring must be conducted for 30 minutes 
beyond the cessation of piling and drilling activities at end of day.
    6. Reporting
    The holder of this Authorization is required to:
    (a) Submit a draft report on all monitoring conducted under the IHA 
within 90 calendar days of the completion of marine mammal monitoring. 
This report must detail the monitoring protocol, summarize the data 
recorded during monitoring, and estimate the number of marine mammals 
that may have been harassed, including the total number extrapolated 
from observed animals across the entirety of relevant monitoring zones. 
Given that the entire Level B harassment zone may not be readily 
observable, takes must be recorded and extrapolated based upon the 
amount of total observed takes and the percentage of the Level B 
harassment zone that was not visible.
    A final report must be prepared and submitted within 30 days 
following resolution of comments on the draft report from NMFS. This 
report must contain the following:
    (i) Date and time a monitored activity begins or ends;
    (ii) Construction activities occurring during each observation 
period;
    (iii) Record of 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;
    (iv) An estimated total take extrapolated from the number of marine 
mammals observed during the course of construction activities, if 
necessary.
    (v) Deviation from initial proposal in pile numbers, pile types, 
average driving times, etc.;
    (vi) Weather parameters (e.g., percent cover, visibility);
    (vii) Water conditions (e.g., sea state, tide state);
    (viii) Species, numbers, and, if possible, sex and age class of 
marine mammals;
    (ix) Description of any observable marine mammal behavior patterns,
    (x) Distance from pile driving activities to marine mammals and 
distance from the marine mammals to the observation point;
    (x) Locations of all marine mammal observations; and
    (xi) Other human activity in the area.
    (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, 
The Port of San Francisco must immediately cease the specified 
activities and report the incident to the Office of Protected 
Resources, NMFS, and the West Coast 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 must not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with the Port of 
San Francisco to determine what measures are necessary to minimize the 
likelihood of further prohibited take and ensure MMPA compliance. The 
Port of San Francisco may not resume their activities until notified by 
NMFS;
    (i) In the event that the Port of San Francisco discovers an 
injured or dead marine mammal, and the lead observer determines that 
the cause of the injury or death is unknown and the death is relatively 
recent (e.g., in less than a moderate state of decomposition), the Port 
of San Francisco must immediately report the incident to the Office of 
Protected Resources, NMFS, and the West Coast Stranding Coordinator, 
NMFS;
    (ii) 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 the Port of San 
Francisco to determine whether additional mitigation measures or 
modifications to the activities are appropriate;
    (iii) In the event that the Port of San Francisco 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), the Port of 
San Francisco must report the incident to the Office of Protected 
Resources, NMFS, and the West Coast Stranding Coordinator, NMFS, within 
24 hours of the discovery. The Port of San Francisco must 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.

Request for Public Comments

    We request comment on our analyses, the proposed authorization, the 
Port's potential sound source verification efforts, 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.
    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:
    <bullet> A request for renewal is received no later than 60 days 
prior to expiration of the current IHA;
    <bullet> 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

[[Page 42490]]

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;
    <bullet> 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: August 16, 2018.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2018-18056 Filed 8-21-18; 8:45 am]
 BILLING CODE 3510-22-P


</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>