Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Central Bay Operations and Maintenance Facility Project, 29486-29511 [2017-13580]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 82, Number 124 (Thursday, June 29, 2017)]
[Notices]
[Pages 29486-29511]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-13580]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF457


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Central Bay Operations and 
Maintenance Facility Project

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

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

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SUMMARY: NMFS has received a request from the San Francisco Bay Area 
Water Emergency Transportation Authority (WETA) for authorization to 
take marine mammals incidental to construction activities as part of 
its Central Bay Operations and Maintenance Facility project. Pursuant 
to the Marine Mammal Protection Act (MMPA), NMFS is requesting public 
comment on its proposal to issue an incidental harassment authorization 
(IHA) to WETA to incidentally take marine mammals, by Level A and Level 
B harassment only, during the specified activity. NMFS will consider 
public comments prior to making any final decision on the issuance of 
the requested MMPA authorizations and agency responses will be 
summarized in the final notice of our decision.

DATES: Comments and information must be received no later than July 31, 
2017.

ADDRESSES: Comments on this proposal 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 ITP.mccue@noaa.gov.
    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 www.nmfs.noaa.gov/pr/permits/incidental/construction.html 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: Laura McCue, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the applications 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION: 

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce (as delegated to NMFS) to allow, upon 
request, the incidental, but not intentional, taking of small numbers 
of marine mammals by U.S. citizens who engage in a specified activity 
(other than commercial fishing) within a specified geographical region 
if certain findings are made and either regulations are issued or, if 
the taking is limited to harassment, a notice of a proposed 
authorization is provided to the public for review.
    An authorization for incidental takings shall be granted if NMFS 
finds that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth.
    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as an 
impact resulting from the specified activity that cannot be reasonably 
expected to, and is not reasonably likely to, adversely affect the 
species or stock through effects on annual rates of recruitment or 
survival.
    The MMPA states that the term ``take'' means to harass, hunt, 
capture, kill or attempt to harass, hunt, capture, or kill any marine 
mammal.
    Except with respect to certain activities not pertinent here, the 
MMPA defines ``harassment'' as: Any act of pursuit, torment, or 
annoyance which (i) has the potential to injure a marine mammal or 
marine mammal stock in the wild (Level A harassment); or (ii) has the 
potential to disturb a marine mammal or marine mammal stock in the wild 
by causing disruption of behavioral patterns, including, but not 
limited to, migration, breathing, nursing, breeding, feeding, or 
sheltering (Level B harassment).

National Environmental Policy Act

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to environmental 
consequences on the human environment.
    This action is consistent with categories of activities identified 
in CE B4 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

[[Page 29487]]

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 May 3, 2017, NMFS received a request from WETA for an IHA to 
take marine mammals incidental to pile driving and removal in 
association with the Central Bay Operations and Maintenance Facility 
Project (Project) in Alameda, California. WETA's request is for take of 
seven species by Level A and Level B harassment. Neither WETA nor NMFS 
expect mortality to result from this activity and, therefore, an IHA is 
appropriate.
    This is the second year of a 2-year project. In-water work 
associated with the second year of construction is expected to be 
completed within 22 days. This proposed IHA is for the second phase of 
construction activities (August 1, 2017 through November 30, 2017). 
WETA received authorization for take of marine mammals incidental to 
these same activities for the first phase of construction in 2016 (80 
FR 10060; February 25, 2015). In addition, similar construction and 
pile driving activities in San Francisco Bay have been authorized by 
NMFS in the past. These projects include construction activities at the 
San Francisco Ferry Terminal (81 FR 43993, July 6, 2016); Exploratorium 
(75 FR 66065, October 27, 2010); Pier 36 (77 FR 20361, April 4, 2012); 
and the San Francisco-Oakland Bay Bridge (71 FR 26750, May 8, 2006; 72 
FR 25748, August 9, 2007; 74 FR 41684, August 18, 2009; 76 FR 7156, 
February 9, 2011; 78 FR 2371, January 11, 2013; 79 FR 2421, January 14, 
2014; and 80 FR 43710, July 23, 2015). This IHA would be valid from 
August 1, 2017, through July 31, 2018.

Description of the Specified Activity

Overview

    WETA is constructing a Central Bay Operations and Maintenance 
Facility to serve as the central San Francisco Bay base for WETA's 
ferry fleet, Operations Control Center (OCC), and Emergency Operations 
Center (EOC). The Project will provide maintenance services such as 
fueling, engine oil changes, concession supply, and light repair work 
for WETA ferry boats operating in the central San Francisco Bay. In 
addition, the project will be the location for operational activities 
of WETA, including day-to-day management and oversight of services, 
crew, and facilities. In the event of a regional disaster, the facility 
will also function as an EOC, serving passengers and sustaining water 
transit service for emergency response and recovery.
    The first year of the Project included construction to the landside 
facility, marine facility, berthing floats, gangway, fueling facility, 
utilities, stormwater drainage, and site access. Construction occurred 
over 4 months in 2016 and included seawall construction and floating 
marina pile removal.

Dates and Duration

    The total project is expected to require a maximum of 22 days of 
in-water pile driving. In-water activities are limited to occurring 
between August 1 and November 30 of any year to minimize impacts to 
special-status and commercially important fish species, as established 
in WETA's Long-Term Management Strategy. This proposed authorization 
would be effective from August 1, 2017 through July 31, 2018.

Specific Geographic Region

    The Central Bay operations and maintenance facility is located at 
Alameda Point in San Francisco Bay, Alameda, CA (see Figure 1 of WETA's 
application). The project site is bounded on the east by the Bay Trail 
and an undeveloped park; and on the north by a paved open area and West 
Hornet Avenue (presently not a public right-of-way), which is defined 
by curbs and pavement stripes. Pier 3 lies to the west of the site, 
along with the USS Hornet, a functioning museum and designated national 
historic landmark. The United States Department of Transportation 
Maritime Administration leases the property west and north of the site, 
including a landside building and several piers from the City of 
Alameda. A concrete seawall delineates the southern edge of the 
landside portion; the seawall is tilted and cracked, and riprap and 
broken concrete span the area between the seawall and the water. 
Ambient sound levels are not available near Alameda Point; however, in 
this industrial area, ambient sound levels may exceed 120 dB RMS as a 
result of the nearly continuous noise from recreational and commercial 
boat traffic.

Detailed Description of Activities

    The second phase of the project includes construction of berthing 
slips and a system of platforms and access ramps. In 2017, the project 
activities will include both the removal and installation of steel 
piles as summarized in Table 1. Demolition and construction could be 
completed within 22 days. Structural piles in the water will be driven 
in place by a diesel impact hammer or with a vibratory hammer. 
Vibratory driving is the preferred method and will be used unless a 
pile encounters harder substrate that requires the use of an impact 
hammer to complete installation. Vibratory driving would require 200 to 
320 seconds of driving per pile. For impact driving, each pile will 
require approximately 450 to 600 hammer strikes to put each pile in 
place. It is estimated that two to three piles will be driven per day 
during in-water pile-driving operations. Temporary template piles will 
be installed to guide pile installation. These template piles will 
consist of steel H-piles and would be installed and extracted using 
vibratory methods.
    A total of 29 steel pipe piles, ranging from 24 inches to 42 inches 
in diameter, will be driven in 2017; 20 (14-inch) H-piles will 
temporarily be installed and then removed in 2017 (Table 1).

                      Table 1--Summary of Pile Removal and Installation for 2017 Activities
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                                                                                                Total number of
         Project element             Pile diameter         Pile type            Method            piles/days
----------------------------------------------------------------------------------------------------------------
Float Guide Pile Installation...  42 inches.........  Steel Pipe........  Impact Driver, 600  15 piles/8 days (2
                                                                           blows/pile OR       piles per day).
                                                                           Vibratory Driver,
                                                                           320 seconds/pile.
Donut Pile Installation.........  36 inches.........  Steel Pipe........  Impact Driver, 600  6 piles/3 days (2
                                                                           blows/pile OR       piles per day).
                                                                           Vibratory Driver,
                                                                           300 seconds/pile.
Dolphin Pile Installation.......  24 inches.........  Steel Pipe........  Impact Driver, 450  8 piles/3 days (3
                                                                           blows/pile OR       piles per day).
                                                                           Vibratory Driver,
                                                                           205 seconds/pile.
Template Pile Installation and    14 inches.........  Steel H[dash]piles  Vibratory Driver,   20 piles/days (5
 Extraction.                                                               120 seconds/pile.   piles per day,
                                                                                               installation and
                                                                                               extraction).
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[[Page 29488]]

    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 the Specified Activity

    There are seven marine mammal species that may inhabit or may 
likely transit through the waters nearby the project area, and are 
expected to potentially be taken by the specified activity. These 
include the Pacific harbor seal (Phoca vitulina), California sea lion 
(Zalophus californianus), northern elephant seal (Mirounga 
angustirostris), northern fur seal (Callorhinus ursinus), harbor 
porpoise (Phocoena phocoena), gray whale (Eschrichtius robustus), and 
bottlenose dolphin (Tursiops truncatus). Multiple additional marine 
mammal species may occasionally enter the activity area in San 
Francisco Bay but would not be expected to occur in shallow nearshore 
waters of the action area. Guadalupe fur seals (Arctocephalus philippii 
townsendi) generally do not occur in San Francisco Bay, however, there 
have been recent sightings of this species due to an El Ni[ntilde]o 
event. Only single individuals of this species have occasionally been 
sighted inside San Francisco Bay, and their presence near the action 
area is considered unlikely. No takes are requested for this species, 
and a shutdown zone will be in effect for this species if observed 
approaching the Level B harassment zone. Although it is possible that a 
humpback whale (Megaptera novaeangliae) may enter San Francisco Bay and 
find its way into the project area during construction activities, 
their occurrence is unlikely, since humpback whales very rarely enter 
the San Francisco Bay area. No takes are requested for this species, 
and a delay and shutdown procedure will be in effect for this species 
if observed approaching the Level B harassment zone.
    Sections 4 and 5 of WETA's application summarize available 
information regarding status and trends, distribution and habitat 
preferences, and behavior and life history, of the potentially affected 
species. Additional information regarding population trends and threats 
may be found in NMFS's Stock Assessment Reports (SAR; 
www.nmfs.noaa.gov/pr/sars/) and more general information about these 
species (e.g., physical and behavioral descriptions) may be found on 
NMFS's Web site (www.nmfs.noaa.gov/pr/species/mammals/).
    Table 2 lists all species with expected potential for occurrence in 
San Francisco Bay near Alameda Point and summarizes information related 
to the population or stock, including potential biological removal 
(PBR), where known. For taxonomy, we follow Committee on Taxonomy 
(2016). PBR is defined by the MMPA as the maximum number of animals, 
not including natural mortalities, that may be removed from a marine 
mammal stock while allowing that stock to reach or maintain its optimum 
sustainable population (as described in NMFS's SARs). While no 
mortality is anticipated or authorized here, PBR and annual serious 
injury and mortality are included here as gross indicators of the 
status of the species and other threats.
    Species that could potentially occur in the proposed survey areas, 
but are not expected to have reasonable potential to be harassed by in-
water construction, are described briefly but omitted from further 
analysis. These include extralimital species, which are species that do 
not normally occur in a given area but for which there are one or more 
occurrence records that are considered beyond the normal range of the 
species (e.g. humpback whales and Guadalupe fur seal). For status of 
species, we provide information regarding U.S. regulatory status under 
the MMPA and ESA.
    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 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 draft 
U.S. Pacific SARs (e.g., NMFS 2016). All values presented in Table 2 
are the most recent available at the time of publication and are 
available in the draft 2016 SARs (NMFS 2016).

                                                          Table 2--Marine Mammals Potentially Present in the Vicinity of Alameda Point
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                                                               ESA/MMPA status;
               Species                         Stock            Strategic (Y/N)        Stock abundance (CV, Nmin, most recent          PBR \3\       Relative occurrence in San Francisco Bay;
                                                                      \1\                      abundance survey) \2\                                           season of  occurrence
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
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Family Phocoenidae (porpoises):
    Harbor porpoise (Phocoena         San Francisco-Russian   -; N..............  9,886 (0.51; 6,625; 2011)......................              66  Common.
     phocoena).                        River.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae (dolphins):
    Bottlenose dolphin \4\ (Tursiops  California coastal....  -; N..............  453 (0.06; 346; 2011)..........................             2.4  Rare.
     truncatus).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Order Cetartiodactyla--Cetacea--Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae:
    Gray whale (Eschrichtius          Eastern N. Pacific....  -; N..............  20,990 (0.05; 20,125; 2011)....................             624  Rare.
     robustus).
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[[Page 29489]]

 
                                                              Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
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Family Balaenopteridae:
    Humpback whale (Megaptera         California/Oregon/      T \5\; S..........  1,918 (0.05; 1,876; 2014)......................              11  Unlikely.
     novaeangliae).                    Washington stock.
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                                                                             Order Carnivora--Superfamily Pinnipedia
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Family Otariidae (eared seals and
 sea lions):
    California sea lion (Zalophus     U.S...................  -; N..............  296,750 (n/a; 153,337; 2011)...................           9,200  Common.
     californianus).
    Guadalupe fur seal \5\            Mexico to California..  T; S..............  20,000 (n/a; 15,830; 2010).....................              91  Unlikely.
     (Arctocephalus philippii
     townsendi).
    Northern fur seal (Callorhinus    California stock......  -; N..............  14,050 (n/a; 7,524; 2013)......................             451  Unlikely.
     ursinus).
    Family Phocidae (earless seals):
    Harbor seal (Phoca vitulina)....  California............  -; N..............  30,968 (n/a; 27,348; 2012).....................           1,641  Common; Year-round resident.
    Northern elephant seal (Mirounga  California breeding     -; N..............  179,000 (n/a; 81,368; 2010)....................           4,882  Rare.
     angustirostris).                  stock.
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\1\ 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 (see footnote 3) 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\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For certain stocks, abundance estimates are actual counts of animals
  and there is no associated CV. The most recent abundance survey that is reflected in the abundance estimate is presented; there may be more recent surveys that have not yet been incorporated
  into the estimate.
\3\ Potential biological removal, 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 size (OSP).
\4\ Abundance estimates for these stocks are greater than eight years old and are, therefore, not considered current. PBR is considered undetermined for these stocks, as there is no current
  minimum abundance estimate for use in calculation. We nevertheless present the most recent abundance estimates and PBR values, as these represent the best available information for use in
  this document.
\5\ The humpback whales considered under the MMPA to be part of this stock could be from any of three different DPSs. In CA, it would be expected to primarily be whales from the Mexico DPS but
  could also be whales from the Central America DPS.

    Below, for those species that are likely to be taken by the 
activities described, we offer a brief introduction to the species and 
relevant stock. We also provide information regarding population trends 
and threats, and describe any information regarding local occurrence.

Harbor Seal

    The Pacific harbor seal is one of five subspecies of Phoca 
vitulina, or the common harbor seal. There are five species of harbor 
seal in the Pacific EEZ: (1) California stock; (2) Oregon/Washington 
coast stock; (3) Washington Northern inland waters stock; (4) Southern 
Puget Sound stock; and (5) Hood Canal stock. Only the California stock 
occurs in the action area and is analyzed in this document. The current 
abundance estimate for this stock is 30,968. This stock is not 
considered strategic or designated as depleted under the MMPA and is 
not listed under the ESA. PBR is 1,641 animals per year. The average 
annual rate of incidental commercial fishery mortality (30 animals) is 
less than 10 percent of the calculated PBR (1,641 animals); therefore, 
fishery mortality is considered insignificant (Carretta et al., 2016).
    Although generally solitary in the water, harbor seals congregate 
at haulouts to rest, socialize, breed, and molt. Habitats used as haul-
out sites include tidal rocks, bayflats, sandbars, and sandy beaches 
(Zeiner et al., 1990). Haul-out sites are relatively consistent from 
year-to-year (Kopec and Harvey 1995), and females have been recorded 
returning to their own natal haul-out when breeding (Cunningham et al., 
2009).
    Long-term monitoring studies have been conducted at the largest 
harbor seal colonies in Point Reyes National Seashore and Golden Gate 
National Recreation Area since 1976. Castro Rocks and other haulouts in 
San Francisco Bay are part of the regional survey area for this study 
and have been included in annual survey efforts. Between 2007 and 2012, 
the average number of adults observed ranged from 126 to 166 during the 
breeding season (March through May), and from 92 to 129 during the 
molting season (June through July) (Truchinski et al., 2008; Flynn et 
al., 2009; Codde et al., 2010; Codde et al., 2011; Codde et al., 2012; 
Codde and Allen 2015). Marine mammal monitoring at multiple locations 
inside San Francisco Bay was conducted by Caltrans from May 1998 to 
February 2002, and determined that at least 500 harbor seals populate 
San Francisco Bay (Green et al., 2002). This estimate is consistent 
with previous seal counts in the San Francisco Bay, which ranged from 
524 to 641 seals from 1987

[[Page 29490]]

to 1999 (Goals Project 2000). Although harbor seals haul-out at 
approximately 20 locations in San Francisco Bay, there are three 
locations that serve as primary locations: Mowry Slough in the south 
Bay, Corte Madera Marsh and Castro Rocks in the north Bay, and Yerba 
Buena Island in the central Bay (Grigg 2008; Gibble 2011). The main 
pupping areas in the San Francisco Bay are at Mowry Slough and Castro 
Rocks (Caltrans 2012). Pupping season for harbor seals in San Francisco 
Bay spans from approximately March 15 through May 31, with pup numbers 
generally peaking in late April or May (Carretta et al., 2016). Births 
of harbor seals have not been observed at Corte Madera Marsh and Yerba 
Buena Island, but a few pups have been seen at these sites.
    Harbor seals occasionally use the westernmost tip of Breakwater 
Island as a haul[hyphen]out site and forage in the Breakwater Gap area. 
The tip is approximately one mile west of the project site. Aerial 
surveys of seal haul[hyphen]outs conducted in 1995-97 and incidental 
counts made during summer tern foraging studies conducted in 1984-93 
usually counted fewer than 10 seals present at any one time. There is 
some evidence that more harbor seals have been using the westernmost 
tip of Breakwater Island in recent years, or that it is more important 
as a winter haul[hyphen]out. Seventy[hyphen]three seals were counted on 
Breakwater Island in January 1997, and 20 were observed 
hauled[hyphen]out on April 4, 1998. A small pup was observed during May 
1997; however, site characteristics are not ideal for the island to be 
a major pupping area (USFWS, 1998). Recent observations indicate that 
as many as 32 harbor seals irregularly haul out on Breakwater Island 
(Klein 2017).
    WETA constructed a floating haul-out platform to replace the 
deteriorating dock that hosted hauled out harbor seals since 2010, 
which was removed at the project site. This new platform is 
approximately 1,000 feet (305 meters (m)) southwest of the project site 
and was constructed in June 2016. Use of the platform by seals has 
increased steadily since its installation, with as many as 70 seals 
observed on the platform at once (Bay Nature 2017). Volunteer 
monitoring of harbor seal use of the haul-out platform has been 
conducted since its installation. The average number of animals hauled 
out from June 2016 to April 2017 is 15 seals. Monitoring during pile 
driving work in September 2016 found that approximately 0.5 harbor seal 
per day were observed within 130 meters of the point source. During 
dredging monitoring in November 2016, approximately 1.6 harbor seals 
per day were observed within 130 meters of the source (i.e., the dredge 
bucket). The increase in seal observations may be due to seasonal 
changes, or may be due to increased visitation of the platform as more 
seals became aware and familiar with the structure that was installed 
in June of 2016. Using the higher (November 2016) average, it is 
estimated that up to 18 harbor seals (1.6 seals per day on 11 
anticipated days of impact driving) may enter the 130 meter Level A 
zone during impact pile driving of the 42- and 36-in steel piles.
    The nearest harbor seal pupping location is Yerba Buena Island, 
approximately 4.5 miles from the project vicinity. Harbor seals use 
Yerba Buena Island year-round, with the largest numbers seen during 
winter months, when Pacific Herring spawn (Grigg 2008). During marine 
mammal monitoring for construction of the new Bay Bridge, harbor seal 
counts at Yerba Buena Island ranged from zero to a maximum of 188 
individuals (Caltrans 2012). Higher numbers also occur during molting 
and breeding seasons. Foraging areas in the vicinity are concentrated 
between Yerba Buena Island and Treasure Island, and an area southeast 
of Yerba Buena Island (Caltrans 2015b).

California Sea Lion

    California sea lions range all along the western border of North 
America. The breeding areas of the California sea lion are on islands 
located in southern California, western Baja California, and the Gulf 
of California (Allen and Angliss 2015). Although California sea lions 
forage and conduct many activities in the water, they also use haul-
outs. California sea lions breed in Southern California and along the 
Channel Islands during the spring. The current population estimate for 
California sea lions is 296,750 animals. This species is not considered 
strategic under the MMPA, and is not designated as depleted. This 
species is also not listed under the ESA. PBR is 9,200 (Carretta et 
al., 2016). Interactions with fisheries, boat collisions, human 
interactions, and entanglement are the main threats to this species 
(Carretta et al., 2016).
    El Ni[ntilde]o affects California sea lion populations, with 
increased observations and strandings of this species in the area. 
Current observations of this species in CA have increased significantly 
over the past few years. Additionally, as a result of the large numbers 
of sea lion strandings in 2013, NOAA declared an unusual mortality 
event (UME). Although the exact causes of this UME are unknown, two 
hypotheses meriting further study include nutritional stress of pups 
resulting from a lack of forage fish available to lactating mothers and 
unknown disease agents during that time period.
    In San Francisco Bay, sea lions haul out primarily on floating K 
docks at Pier 39 in the Fisherman's Wharf area of the San Francisco 
Marina. The Pier 39 haul out is approximately 6.5 miles from the 
project vicinity. The Marine Mammal Center (TMMC) in Sausalito, 
California has performed monitoring surveys at this location since 
1991. A maximum of 1,706 sea lions was seen hauled out during one 
survey effort in 2009 (TMMC 2015). Winter numbers are generally over 
500 animals (Goals Project 2000). In August to September, counts 
average from 350 to 850 (NMFS 2004). Of the California sea lions 
observed, approximately 85 percent were male. No pupping activity has 
been observed at this site or at other locations in the San Francisco 
Bay (Caltrans 2012). The California sea lions usually frequent Pier 39 
in August after returning from the Channel Islands (Caltrans 2013). In 
addition to the Pier 39 haul-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.
    California sea lions have not been documented using the Alameda 
breakwater or haul-out platform, though it is anticipated that they may 
occasionally use the structures in Alameda Harbor that are known to be 
used by harbor seals.
    Although there is little information regarding the foraging 
behavior of the California sea lion in the San Francisco Bay, they have 
been observed foraging on a regular basis in the shipping channel south 
of Yerba Buena Island. Foraging grounds have also been identified for 
pinnipeds, including sea lions, between Yerba Buena Island and Treasure 
Island, as well as off the Tiburon Peninsula (Caltrans 2001).

Northern Elephant Seal

    Northern elephant seals breed and give birth in California (U.S.) 
and Baja California (Mexico), primarily on offshore islands (Stewart et 
al., 1994), from December to March (Stewart and Huber 1993). Although 
movement and genetic exchange continues between rookeries, most 
elephant seals return to natal rookeries when they start breeding 
(Huber et al., 1991). The California breeding population is now 
demographically isolated from the Baja

[[Page 29491]]

California population, and is the only stock to occur near the action 
area. The current abundance estimate for this stock is 179,000 animals, 
with PBR at 4,882 animals (Carretta et al., 2016). The population is 
reported to have grown at 3.8 percent annually since 1988 (Lowry et 
al., 2014). Fishery interactions and marine debris entanglement are the 
biggest threats to this species (Carretta et al., 2016). Northern 
elephant seals are not listed under the Endangered Species Act, nor are 
they designated as depleted, or considered strategic under the MMPA.
    Northern elephant seals are common on California coastal mainland 
and island sites where they pup, breed, rest, and molt. The largest 
rookeries are on San Nicolas and San Miguel islands in the Northern 
Channel Islands. In the vicinity of San Francisco Bay, elephant seals 
breed, molt, and haul out at A[ntilde]o Nuevo Island, the Farallon 
Islands, and Point Reyes National Seashore (Lowry et al., 2014). Adults 
reside in offshore pelagic waters when not breeding or molting. 
Northern elephant seals haul out to give birth and breed from December 
through March, and pups remain onshore or in adjacent shallow water 
through May, when they may occasionally make brief stops in San 
Francisco Bay (Caltrans 2015b). The most recent sighting was in 2012 on 
the beach at Clipper Cove on Treasure Island, when a healthy yearling 
elephant seal hauled out for approximately one day. Approximately 100 
juvenile northern elephant seals strand in San Francisco Bay each year, 
including individual strandings at Yerba Buena Island and Treasure 
Island (fewer than 10 strandings per year) (Caltrans 2015b). When pups 
of the year return in the late summer and fall to haul out at rookery 
sites, they may also occasionally make brief stops in San Francisco 
Bay.

Northern Fur Seal

    Northern fur seals (Callorhinus ursinus) occur from southern 
California north to the Bering Sea and west to the Okhotsk Sea and 
Honshu Island, Japan. During the breeding season, approximately 74 
percent of the worldwide population is found on the Pribilof Islands in 
the southern Bering Sea, with the remaining animals spread throughout 
the North Pacific Ocean (Lander and Kajimura 1982). Of the seals in 
U.S. waters outside of the Pribilofs, approximately one percent of the 
population is found on Bogoslof Island in the southern Bering Sea, San 
Miguel Island off southern California (NMFS 2007), and the Farallon 
Islands off central California. Two separate stocks of northern fur 
seals are recognized within U.S. waters: an Eastern Pacific stock and a 
California stock (including San Miguel Island and the Farallon 
Islands). Only the California breeding stock is considered here since 
it is the only stock to occur near the action area. The current 
abundance estimate for this stock is 14,050 and PBR is set at 451 
animals (Carretta et al., 2015). This stock has grown exponentially 
during the past several years. Interaction with fisheries remains the 
top threat to this species (Carretta et al., 2015). This stock is not 
considered depleted or classified as strategic under the MMPA, and is 
not listed under the ESA.

Harbor Porpoise

    In the Pacific, harbor porpoise are found in coastal and inland 
waters from Point Conception, California to Alaska and across to 
Kamchatka and Japan (Gaskin 1984). Harbor porpoise appear to have more 
restricted movements along the western coast of the continental U.S. 
than along the eastern coast. Regional differences in pollutant 
residues in harbor porpoise indicate that they do not move extensively 
between California, Oregon, and Washington (Calambokidis and Barlow 
1991). That study also showed some regional differences within 
California (Allen and Angliss 2014). Of the 10 stocks of Pacific harbor 
porpoise, only the San Francisco-Russian River stock is considered here 
since it is the only stock to occur near the action area. This current 
abundance estimate for this stock is 9,886 animals, with a PBR of 66 
animals (Carretta et al., 2015). Current population trends are not 
available for this stock. The main threats to this stock include 
fishery interactions. This stock is not designated as strategic or 
considered depleted under the MMPA, and is not listed under the ESA.
    In recent years, however, there have been increasingly common 
observations of harbor porpoises in central, north, and south San 
Francisco Bay. According to observations by the Golden Gate Cetacean 
Research team as part of their multi-year assessment, more than 100 
porpoises may be seen at one time entering San Francisco Bay; and more 
than 600 individual animals are documented in a photo-ID database. 
Porpoise activity inside San Francisco Bay is thought to be related to 
foraging and mating behaviors (Keener 2011; Duffy 2015). 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 (Keener 2011) and near the project area.

Gray Whale

    Once common throughout the Northern Hemisphere, the gray whale was 
extinct in the Atlantic by the early 1700s. Gray whales are now only 
commonly found in the North Pacific. Genetic comparisons indicate there 
are distinct ``Eastern North Pacific'' (ENP) and ``Western North 
Pacific'' (WNP) population stocks, with differentiation in both 
mitochondrial DNA (mtDNA) haplotype and microsatellite allele 
frequencies (LeDuc et al., 2002; Lang et al., 2011a; Weller et al., 
2013). Only the ENP stock occurs in the action area and is considered 
in this document. The current population estimate for this stock is 
20,990 animals, with PBR at 624 animals (Carretta et al., 2015). The 
population size of the ENP gray whale stock has increased over several 
decades despite an UME in 1999 and 2000 and has been relatively stable 
since the mid-1990s. Interactions with fisheries, ship strikes, 
entanglement in marine debris, and habitat degradation are the main 
concerns for the gray whale population (Carretta et al., 2015). This 
stock is not listed under the ESA, and is not considered a strategic 
stock or designated as depleted under the MMPA.
    Marine Mammal Monitors (MMO) with the Caltrans Richmond-San Rafael 
Bridge project 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 specific years were unreported). The Oceanic Society has tracked 
gray whale sightings since they began returning to San Francisco Bay 
regularly in the late 1990s. The Oceanic Society data show that all age 
classes of gray whales are entering San Francisco Bay, and that they 
enter as singles or in groups of as many as five individuals. However, 
the data do not distinguish between sightings of gray whales and number 
of individual whales (Winning, 2008). It is estimated that two to six 
gray whales enter San Francisco Bay in any given year.

Bottlenose Dolphin

    Bottlenose dolphins are distributed worldwide 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 is distinct from the offshore stock based on significant 
differences in cranial morphology and

[[Page 29492]]

genetics, where the two stocks only share one of 56 haplotypes 
(Carretta et al., 2016). California coastal bottlenose dolphins are 
found within about one kilometer of shore (Hansen 1990; Carretta et 
al., 1998; Defran and Weller 1999) from central California south into 
Mexican waters, at least as far south as San Quintin, Mexico, and the 
area between Ensenada and San Quintin, Mexico may represent a southern 
boundary for the California coastal population (Carretta et al., 2016). 
Oceanographic events appear to influence the distribution of animals 
along the coasts of California and Baja California, Mexico, as 
indicated by El Ni[ntilde]o events. There are seven stocks of 
bottlenose dolphins in the Pacific; however, only the California 
coastal stock may occur in the action area, and is analyzed in this 
proposed IHA. The current stock abundance estimate for the California 
coastal stock is 453 animals, with PBR at 3.3 animals (Carretta et al., 
2016). Pollutant levels in California are a threat to this species, and 
this stock may be vulnerable to disease outbreaks, particularly 
morbillivirus (Carretta et al., 2008). This stock is not listed under 
the ESA, and is not considered strategic or designated as depleted 
under the MMPA.
    Since the 1982-83 El Ni[ntilde]o, which increased water 
temperatures off California, bottlenose dolphins have been consistently 
sighted along the central California coast (NMFS 2008). The northern 
limit of their regular range is currently the Pacific coast off San 
Francisco and Marin County, and they occasionally enter San Francisco 
Bay, sometimes foraging for fish in Fort Point Cove, just east of the 
Golden Gate Bridge, but are most often seen just within the Golden Gate 
when they are present (GGCR, 2016).
    In the summer of 2015, a lone bottlenose dolphin was seen swimming 
in the Oyster Point area of South San Francisco (GGCR 2016) and west of 
Breakwater Island near a navigational buoy (Perlman 2017). It is 
believed that this is the same individual that regularly frequents the 
area (Perlman 2017). Such behavior may be considered abnormal as 
bottlenose dolphins almost always live in social groups.
    Members of the California Coastal Stock are transient and make 
movements up and down the coast, and into some estuaries, throughout 
the year. This stock is highly transitory in nature, and is generally 
not expected to spend extended periods of time in San Francisco Bay. 
Incidental take of this species is being requested in the rare event 
they are present in San Francisco Bay during pile driving.

Potential Effects of the Specified Activity on Marine Mammals and Their 
Habitat

    This section includes a summary and discussion of the ways that 
components of the specified activity (e.g., sound produced by pile 
driving and removal) may impact marine mammals and their habitat. The 
Estimated Take by Incidental Harassment section later in this document 
will include a quantitative analysis of the number of individuals that 
are expected to be taken by this activity. The Negligible Impact 
Analysis section will consider the content of this section, the 
Estimated Take by Incidental Harassment section and the Proposed 
Mitigation section, to draw conclusions regarding the likely impacts of 
these activities on the reproductive success or survivorship of 
individuals and how those impacts on individuals are likely to impact 
marine mammal species or stocks.

Description of Sound Sources

    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude. Frequency is the number 
of pressure waves that pass by a reference point per unit of time and 
is measured in hertz (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 decibel (dB) scale. A dB is the ratio 
between a measured pressure (with sound) and a reference pressure 
(sound at a constant pressure, established by scientific standards). It 
is a logarithmic unit that accounts for large variations in amplitude; 
therefore, relatively small changes in dB ratings correspond to large 
changes in sound pressure. When referring to sound pressure levels 
(SPLs; the sound force per unit area), sound is referenced in the 
context of underwater sound pressure to 1 microPascal ([mu]Pa). One 
pascal is the pressure resulting from a force of one newton exerted 
over an area of one square meter. The source level (SL) represents the 
sound level at a distance of 1 m from the source (referenced to 1 
[mu]Pa). The received level is the sound level at the listener's 
position. Note that all underwater sound levels in this document are 
referenced to a pressure of 1 [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):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson 1995). In general, ambient sound levels tend to increase 
with increasing wind speed and wave height. Surf noise becomes 
important near shore, with measurements collected at a distance of 8.5 
km from shore showing an increase of 10 dB in the 100 to 700 Hz band 
during heavy surf conditions.
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise at 
frequencies above 500 Hz, and

[[Page 29493]]

possibly down to 100 Hz during quiet times.
     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz.
     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.
    The underwater acoustic environment near Alameda Point is likely to 
be dominated by noise from day-to-day port and vessel activities. This 
is a highly industrialized area with high-use from small- to medium-
sized vessels, and larger vessels that use the nearby major shipping 
channel.
    In-water construction activities associated with the project would 
include impact pile driving and vibratory pile driving and removal. The 
sounds produced by these activities fall into one of two general sound 
types: Pulsed and non-pulsed (defined in the following). The 
distinction between these two sound types is important because they 
have differing potential to cause physical effects, particularly with 
regard to hearing (e.g., Ward, 1997 in Southall et al., 2007). Please 
see Southall et al., (2007) for an in-depth discussion of these 
concepts.
    Pulsed sound sources (e.g., explosions, gunshots, sonic booms, 
impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI 1986; Harris 1998; NIOSH 1998; ISO 2003; ANSI 2005) and occur 
either as isolated events or repeated in some succession. Pulsed sounds 
are all characterized by a relatively rapid rise from ambient pressure 
to a maximal pressure value followed by a rapid decay period that may 
include a period of diminishing, oscillating maximal and minimal 
pressures, and generally have an increased capacity to induce physical 
injury as compared with sounds that lack these features.
    Non-pulsed sounds can be tonal, narrowband, or broadband, brief or 
prolonged, and may be either continuous or non-continuous (ANSI 1995; 
NIOSH 1998). Some of these non-pulsed sounds can be transient signals 
of short duration but without the essential properties of pulses (e.g., 
rapid rise time). Examples of non-pulsed sounds include those produced 
by vessels, aircraft, machinery operations such as drilling or 
dredging, vibratory pile driving, and active sonar systems (such as 
those used by the U.S. Navy). The duration of such sounds, as received 
at a distance, can be greatly extended in a highly reverberant 
environment.
    Impact hammers operate by repeatedly dropping a heavy piston onto a 
pile to drive the pile into the substrate. Sound generated by impact 
hammers is characterized by rapid rise times and high peak levels, a 
potentially injurious combination (Hastings and Popper 2005). Vibratory 
hammers install piles by vibrating them and allowing the weight of the 
hammer to push them into the sediment. Vibratory hammers produce 
significantly less sound than impact hammers. Peak SPLs may be 180 dB 
or greater, but are generally 10 to 20 dB lower than SPLs generated 
during impact pile driving of the same-sized pile (Oestman et al., 
2009). Rise time is slower, reducing the probability and severity of 
injury, and sound energy is distributed over a greater amount of time 
(Nedwell and Edwards 2002; Carlson et al., 2005).

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals, 
and exposure to sound can have deleterious effects. To appropriately 
assess these potential effects, 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 
measured or estimated hearing ranges on the basis of available 
behavioral data, audiograms derived using auditory evoked potential 
techniques, anatomical modeling, and other data. The lower and/or upper 
frequencies for some of these functional hearing groups have been 
modified from those designated by Southall et al. (2007). The marine 
mammal hearing groups and the associated frequencies are indicated 
below in Table 3 (note that these frequency ranges do not necessarily 
correspond to the range of best hearing, which varies by species).

   Table 3--Marine Mammal Hearing Groups and Their Generalized Hearing
                                  Range
------------------------------------------------------------------------
             Hearing group                 Generalized hearing range *
------------------------------------------------------------------------
Low-frequency (LF) cetaceans (baleen     7 Hz to 35 kHz.
 whales).
Mid-frequency (MF) cetaceans (dolphins,  150 Hz to 160 kHz.
 toothed whales, beaked whales,
 bottlenose whales).
High-frequency (HF) cetaceans (true      275 Hz to 160 kHz.
 porpoises, Kogia, river dolphins,
 cephalorhynchid, Lagenorhynchus
 cruciger and L. australis).
Phocid pinnipeds (PW) (underwater)       50 Hz to 86 kHz.
 (true seals).

[[Page 29494]]

 
Otariid pinnipeds (OW) (underwater)      60 Hz to 39 kHz.
 (sea lions and fur seals).
------------------------------------------------------------------------
* Represents the generalized hearing range for the entire group as a
  composite (i.e., all species within the group), where individual
  species' hearing ranges are typically not as broad. Generalized
  hearing range chosen based on ~65 dB threshold from normalized
  composite audiogram, with the exception for lower limits for LF
  cetaceans (Southall et al., 2007) and PW pinniped (approximation).

    As mentioned previously in this document, seven marine mammal 
species (three cetaceans and four pinnipeds) may occur in the project 
area. Of these three cetaceans, one is classified as a low-frequency 
cetacean (i.e., gray whale), one is classified as a mid-frequency 
cetacean (i.e., bottlenose dolphin), and one is classified as a high-
frequency cetaceans (i.e., harbor porpoise) (Southall et al., 2007). 
Additionally, harbor seals, Northern fur seals, and Northern elephant 
seals are classified as members of the phocid pinnipeds in water 
functional hearing group while California sea lions are grouped under 
the Otariid pinnipeds in water functional hearing group. A species' 
functional hearing group is a consideration when we analyze the effects 
of exposure to sound on marine mammals.

Acoustic Impacts

    Please refer to the information given previously (Description of 
Sound Sources) regarding sound, characteristics of sound types, and 
metrics used in this document. Anthropogenic sounds cover a broad range 
of frequencies and sound levels and can have a range of highly variable 
impacts on marine life, from none or minor to potentially severe 
responses, depending on received levels, duration of exposure, 
behavioral context, and various other factors. The potential effects of 
underwater sound from active acoustic sources can potentially result in 
one or more of the following; temporary or permanent hearing 
impairment, non-auditory physical or physiological effects, behavioral 
disturbance, stress, and masking (Richardson et al., 1995; Gordon et 
al., 2004; Nowacek et al., 2007; Southall et al., 2007; Gotz et al., 
2009). The degree of effect is intrinsically related to the signal 
characteristics, received level, distance from the source, and duration 
of the sound exposure. In general, sudden, high level sounds can cause 
hearing loss, as can longer exposures to lower level sounds. Temporary 
or permanent loss of hearing will occur almost exclusively for noise 
within an animal's hearing range. We first describe specific 
manifestations of acoustic effects before providing discussion specific 
to WETA's construction activities.
    Richardson et al., (1995) described zones of increasing intensity 
of effect that might be expected to occur, in relation to distance from 
a source and assuming that the signal is within an animal's hearing 
range. First is the area within which the acoustic signal would be 
audible (potentially perceived) to the animal, but not strong enough to 
elicit any overt behavioral or physiological response. The next zone 
corresponds with the area where the signal is audible to the animal and 
of sufficient intensity to elicit behavioral or physiological 
responsiveness. Third is a zone within which, for signals of high 
intensity, the received level is sufficient to potentially cause 
discomfort or tissue damage to auditory or other systems. Overlaying 
these zones to a certain extent is the area within which masking (i.e., 
when a sound interferes with or masks the ability of an animal to 
detect a signal of interest that is above the absolute hearing 
threshold) may occur; the masking zone may be highly variable in size.
    We describe the more severe effects (i.e., permanent hearing 
impairment, certain non-auditory physical or physiological effects) 
only briefly as we do not expect that there is a reasonable likelihood 
that WETA's activities may result in such effects (see below for 
further discussion). Marine mammals exposed to high-intensity sound, or 
to lower-intensity sound for prolonged periods, can experience hearing 
threshold shift (TS), which is the loss of hearing sensitivity at 
certain frequency ranges (Kastak et al., 1999; Schlundt et al., 2000; 
Finneran et al., 2002, 2005b). TS can be permanent (PTS), in which case 
the loss of hearing sensitivity is not fully recoverable, or temporary 
(TTS), in which case the animal's hearing threshold would recover over 
time (Southall et al., 2007). Repeated sound exposure that leads to TTS 
could cause PTS. In severe cases of PTS, there can be total or partial 
deafness, while in most cases the animal has an impaired ability to 
hear sounds in specific frequency ranges (Kryter 1985).
    When PTS occurs, there is physical damage to the sound receptors in 
the ear (i.e., tissue damage), whereas TTS represents primarily tissue 
fatigue and is reversible (Southall et al., 2007). In addition, other 
investigators have suggested that TTS is within the normal bounds of 
physiological variability and tolerance and does not represent physical 
injury (e.g., Ward 1997). Therefore, NMFS does not consider TTS to 
constitute auditory injury.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals--PTS data exists only for a single harbor seal 
(Kastak et al., 2008)--but are assumed to be similar to those in humans 
and other terrestrial mammals. PTS typically occurs at exposure levels 
at least several dB above a 40-dB threshold shift approximates PTS 
onset; e.g., Kryter et al., 1966; Miller, 1974) that inducing mild TTS 
(a 6-dB threshold shift approximates TTS onset; e.g., Southall et al., 
2007). Based on data from terrestrial mammals, a precautionary 
assumption is that the PTS thresholds for impulse sounds (such as 
impact pile driving pulses as received close to the source) are at 
least 6 dB higher than the TTS threshold on a peak-pressure basis and 
PTS cumulative sound exposure level thresholds are 15 to 20 dB higher 
than TTS cumulative sound exposure level thresholds (Southall et al., 
2007). Given the higher level of sound or longer exposure duration 
necessary to cause PTS as compared with TTS, it is considerably less 
likely that PTS could occur.
    Non-auditory physiological effects or injuries that theoretically 
might occur in marine mammals exposed to high level underwater sound or 
as a secondary effect of extreme behavioral reactions (e.g., change in 
dive profile as a result of an avoidance reaction) caused by exposure 
to sound include neurological effects, bubble formation, resonance 
effects, and other types of organ or tissue damage (Cox et al., 2006; 
Southall et al., 2007; Zimmer and Tyack 2007). WETA's activities do not 
involve the use of devices such as explosives or mid-frequency active 
sonar that are associated with these types of effects.

[[Page 29495]]

    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.
    1. Temporary threshold shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to sound (Kryter, 1985). 
While experiencing TTS, the hearing threshold rises, and a sound must 
be at a higher level in order to be heard. In terrestrial and marine 
mammals, TTS can last from minutes or hours to days (in cases of strong 
TTS). In many cases, hearing sensitivity recovers rapidly after 
exposure to the sound ends. Few data on sound levels and durations 
necessary to elicit mild TTS have been obtained for marine mammals.
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to 
serious. For example, a marine mammal may be able to readily compensate 
for a brief, relatively small amount of TTS in a non-critical frequency 
range that occurs during a time where ambient noise is lower and there 
are not as many competing sounds present. Alternatively, a larger 
amount and longer duration of TTS sustained during 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, beluga whale (Delphinapterus leucas), harbor 
porpoise, and Yangtze finless porpoise (Neophocoena asiaeorientalis) 
and three species of pinnipeds (northern elephant seal, harbor seal, 
and California sea lion) exposed to a limited number of sound sources 
(i.e., mostly tones and octave-band noise) in laboratory settings 
(e.g., Finneran et al., 2002; Nachtigall et al., 2004; Kastak et al., 
2005; Lucke et al., 2009; Popov et al., 2011). In general, harbor seals 
(Kastak et al., 2005; Kastelein et al., 2012a) and harbor porpoises 
(Lucke et al., 2009; Kastelein et al., 2012b) have a lower TTS onset 
than other measured pinniped or cetacean species. Additionally, the 
existing marine mammal TTS data come from a limited number of 
individuals within these species. There are no data available on noise-
induced hearing loss for mysticetes. For summaries of data on TTS in 
marine mammals or for further discussion of TTS onset thresholds, 
please see Southall et al., (2007) and Finneran and Jenkins (2012).
    2. Behavioral effects--Behavioral disturbance may include a variety 
of effects, including subtle changes in behavior (e.g., minor or brief 
avoidance of an area or changes in vocalizations), more conspicuous 
changes in similar behavioral activities, and more sustained and/or 
potentially severe reactions, such as displacement from or abandonment 
of high-quality habitat. Behavioral responses to sound are highly 
variable and context-specific and any reactions depend on numerous 
intrinsic and extrinsic factors (e.g., species, state of maturity, 
experience, current activity, reproductive state, auditory sensitivity, 
time of day), as well as the interplay between factors (e.g., 
Richardson et al., 1995; Wartzok et al., 2003; Southall et al., 2007; 
Weilgart, 2007; Archer et al., 2010). Behavioral reactions can vary not 
only among individuals but also within an individual, depending on 
previous experience with a sound source, context, and numerous other 
factors (Ellison et al., 2012), and can vary depending on 
characteristics associated with the sound source (e.g., whether it is 
moving or stationary, number of sources, distance from the source). 
Please see Appendices B-C of Southall et al., (2007) for a review of 
studies involving marine mammal behavioral responses to sound.
    Habituation can occur when an animal's response to a stimulus wanes 
with repeated exposure, usually in the absence of unpleasant associated 
events (Wartzok et al., 2003). Animals are most likely to habituate to 
sounds that are predictable and unvarying. It is important to note that 
habituation is appropriately considered as a ``progressive reduction in 
response to stimuli that are perceived as neither aversive nor 
beneficial,'' rather than as, more generally, moderation in response to 
human disturbance (Bejder et al., 2009). The opposite process is 
sensitization, when an unpleasant experience leads to subsequent 
responses, often in the form of avoidance, at a lower level of 
exposure. As noted, behavioral state may affect the type of response. 
For example, animals that are resting may show greater behavioral 
change in response to disturbing sound levels than animals that are 
highly motivated to remain in an area for feeding (Richardson et al., 
1995; NRC, 2003; Wartzok et al., 2003). Controlled experiments with 
captive marine mammals have showed pronounced behavioral reactions, 
including avoidance of loud sound sources (Ridgway et al., 1997; 
Finneran et al., 2003). Observed responses of wild marine mammals to 
loud pulsed sound sources (typically seismic airguns or acoustic 
harassment devices) have been varied but often consist of avoidance 
behavior or other behavioral changes suggesting discomfort (Morton and 
Symonds, 2002; see also Richardson et al., 1995; Nowacek et al., 2007).
    Available studies show wide variation in response to underwater 
sound; therefore, it is difficult to predict specifically how any given 
sound in a particular instance might affect marine mammals perceiving 
the signal. If a marine mammal does react briefly to an underwater 
sound by changing its behavior or moving a small distance, the impacts 
of the change are unlikely to be significant to the individual, let 
alone the stock or population. However, if a sound source displaces 
marine mammals from an important feeding or breeding area for a 
prolonged period, impacts on individuals and populations could be 
significant (e.g., Lusseau and Bejder 2007; Weilgart 2007; NRC 2005). 
However, there are broad categories of potential response, which we 
describe in greater detail here, that include alteration of dive 
behavior, alteration of foraging behavior, effects to breathing, 
interference with or alteration of vocalization, avoidance, and flight.
    Changes in dive behavior can vary widely, and may consist of 
increased or decreased dive times and surface intervals as well as 
changes in the rates of ascent and descent during a dive (e.g., Frankel 
and Clark 2000; Costa et al., 2003; Ng and Leung 2003; Nowacek et al., 
2004; Goldbogen et al., 2013a,b). Variations in dive behavior may 
reflect interruptions in biologically significant activities (e.g., 
foraging) or they may be of little biological significance. The impact 
of an alteration to dive behavior resulting from an acoustic exposure 
depends on what the animal is doing at

[[Page 29496]]

the time of the exposure and the type and magnitude of the response.
    Disruption of feeding behavior can be difficult to correlate with 
anthropogenic sound exposure, so it is usually inferred by observed 
displacement from known foraging areas, the appearance of secondary 
indicators (e.g., bubble nets or sediment plumes), or changes in dive 
behavior. As for other types of behavioral response, the frequency, 
duration, and temporal pattern of signal presentation, as well as 
differences in species sensitivity, are likely contributing factors to 
differences in response in any given circumstance (e.g., Croll et al., 
2001; Nowacek et al.; 2004; Madsen et al., 2006; Yazvenko et al., 
2007). A determination of whether foraging disruptions incur fitness 
consequences would require information on or estimates of the energetic 
requirements of the affected individuals and the relationship between 
prey availability, foraging effort and success, and the life history 
stage of the animal.
    Variations in respiration naturally vary with different behaviors 
and alterations to breathing rate as a function of acoustic exposure 
can be expected to co-occur with other behavioral reactions, such as a 
flight response or an alteration in diving. However, respiration rates 
in and of themselves may be representative of annoyance or an acute 
stress response. Various studies have shown that respiration rates may 
either be unaffected or could increase, depending on the species and 
signal characteristics, again highlighting the importance in 
understanding species differences in the tolerance of underwater noise 
when determining the potential for impacts resulting from anthropogenic 
sound exposure (e.g., Kastelein et al., 2001, 2005b, 2006; Gailey et 
al., 2007).
    Marine mammals vocalize for different purposes and across multiple 
modes, such as whistling, echolocation click production, calling, and 
singing. Changes in vocalization behavior in response to anthropogenic 
noise can occur for any of these modes and may result from a need to 
compete with an increase in background noise or may reflect increased 
vigilance or a startle response. For example, in the presence of 
potentially masking signals, humpback whales and killer whales have 
been observed to increase the length of their songs (Miller et al., 
2000; Fristrup et al., 2003; Foote et al., 2004), while right whales 
have been observed to shift the frequency content of their calls upward 
while reducing the rate of calling in areas of increased anthropogenic 
noise (Parks et al., 2007b). In some cases, animals may cease sound 
production during production of aversive signals (Bowles et al., 1994).
    Avoidance is the displacement of an individual from an area or 
migration path as a result of the presence of a sound or other 
stressors, and is one of the most obvious manifestations of disturbance 
in marine mammals (Richardson et al., 1995). For example, gray whales 
are known to change direction--deflecting from customary migratory 
paths--in order to avoid noise from seismic surveys (Malme et al., 
1984). Avoidance may be short-term, with animals returning to the area 
once the noise has ceased (e.g., Bowles et al., 1994; Goold, 1996; 
Stone et al., 2000; Morton and Symonds, 2002; Gailey et al., 2007). 
Longer-term displacement is possible, however, which may lead to 
changes in abundance or distribution patterns of the affected species 
in the affected region if habituation to the presence of the sound does 
not occur (e.g., Blackwell et al., 2004; Bejder et al., 2006; Teilmann 
et al., 2006).
    A flight response is a dramatic change in normal movement to a 
directed and rapid movement away from the perceived location of a sound 
source. The flight response differs from other avoidance responses in 
the intensity of the response (e.g., directed movement, rate of 
travel). Relatively little information on flight responses of marine 
mammals to anthropogenic signals exist, although observations of flight 
responses to the presence of predators have occurred (Connor and 
Heithaus 1996). The result of a flight response could range from brief, 
temporary exertion and displacement from the area where the signal 
provokes flight to, in extreme cases, marine mammal strandings (Evans 
and England 2001). However, it should be noted that response to a 
perceived predator does not necessarily invoke flight (Ford and Reeves 
2008), and whether individuals are solitary or in groups may influence 
the response.
    Behavioral disturbance can also impact marine mammals in more 
subtle ways. Increased vigilance may result in costs related to 
diversion of focus and attention (i.e., when a response consists of 
increased vigilance, it may come at the cost of decreased attention to 
other critical behaviors such as foraging or resting). These effects 
have generally not been demonstrated for marine mammals, but studies 
involving fish and terrestrial animals have shown that increased 
vigilance may substantially reduce feeding rates (e.g., Beauchamp and 
Livoreil 1997; Fritz et al., 2002; Purser and Radford 2011). In 
addition, chronic disturbance can cause population declines through 
reduction of fitness (e.g., decline in body condition) and subsequent 
reduction in reproductive success, survival, or both (e.g., Harrington 
and Veitch, 1992; Daan et al., 1996; Bradshaw et al., 1998). However, 
Ridgway et al. (2006) reported that increased vigilance in bottlenose 
dolphins exposed to sound over a five-day period did not cause any 
sleep deprivation or stress effects.
    Many animals perform vital functions, such as feeding, resting, 
traveling, and socializing, on a diel cycle (24-hour cycle). Disruption 
of such functions resulting from reactions to stressors such as sound 
exposure are more likely to be significant if they last more than one 
diel cycle or recur on subsequent days (Southall et al., 2007). 
Consequently, a behavioral response lasting less than one day and not 
recurring on subsequent days is not considered particularly severe 
unless it could directly affect reproduction or survival (Southall et 
al., 2007). Note that there is a difference between multi-day 
substantive behavioral reactions and multi-day anthropogenic 
activities. For example, just because an activity lasts for multiple 
days does not necessarily mean that individual animals are either 
exposed to activity-related stressors for multiple days or, further, 
exposed in a manner resulting in sustained multi-day substantive 
behavioral responses.
    3. Stress responses--An animal's perception of a threat may be 
sufficient to trigger stress responses consisting of some combination 
of behavioral responses, autonomic nervous system responses, 
neuroendocrine responses, or immune responses (e.g., Seyle, 1950; 
Moberg, 2000). In many cases, an animal's first and sometimes most 
economical (in terms of energetic costs) response is behavioral 
avoidance of the potential stressor. Autonomic nervous system responses 
to stress typically involve changes in heart rate, blood pressure, and 
gastrointestinal activity. These responses have a relatively short 
duration and may or may not have a significant long-term effect on an 
animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha 
2000).

[[Page 29497]]

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).
    4. Auditory masking--Sound can disrupt behavior through masking, or 
interfering with, an animal's ability to detect, recognize, or 
discriminate between acoustic signals of interest (e.g., those used for 
intraspecific communication and social interactions, prey detection, 
predator avoidance, navigation) (Richardson et al., 1995). Masking 
occurs when the receipt of a sound is interfered with by another 
coincident sound at similar frequencies and at similar or higher 
intensity, and may occur whether the sound is natural (e.g., snapping 
shrimp, wind, waves, precipitation) or anthropogenic (e.g., shipping, 
sonar, seismic exploration) in origin. The ability of a noise source to 
mask biologically important sounds depends on the characteristics of 
both the noise source and the signal of interest (e.g., signal-to-noise 
ratio, temporal variability, direction), in relation to each other and 
to an animal's hearing abilities (e.g., sensitivity, frequency range, 
critical ratios, frequency discrimination, directional discrimination, 
age or TTS hearing loss), and existing ambient noise and propagation 
conditions.
    Under certain circumstances, marine mammals experiencing 
significant masking could also be impaired from maximizing their 
performance fitness in survival and reproduction. Therefore, when the 
coincident (masking) sound is man-made, it may be considered harassment 
when disrupting or altering critical behaviors. It is important to 
distinguish TTS and PTS, which persist after the sound exposure, from 
masking, which occurs during the sound exposure. Because masking 
(without resulting in TS) is not associated with abnormal physiological 
function, it is not considered a physiological effect, but rather a 
potential behavioral effect.
    The frequency range of the potentially masking sound is important 
in determining any potential behavioral impacts. For example, low-
frequency signals may have less effect on high-frequency echolocation 
sounds produced by odontocetes but are more likely to affect detection 
of mysticete communication calls and other potentially important 
natural sounds such as those produced by surf and some prey species. 
The masking of communication signals by anthropogenic noise may be 
considered as a reduction in the communication space of animals (e.g., 
Clark et al., 2009) and may result in energetic or other costs as 
animals change their vocalization behavior (e.g., Miller et al., 2000; 
Foote et al., 2004; Parks et al., 2007b; Di Iorio and Clark 2009; Holt 
et al., 2009). Masking can be reduced in situations where the signal 
and noise come from different directions (Richardson et al., 1995), 
through amplitude modulation of the signal, or through other 
compensatory behaviors (Houser and Moore 2014). Masking can be tested 
directly in captive species (e.g., Erbe 2008), but in wild populations 
it must be either modeled or inferred from evidence of masking 
compensation. There are few studies addressing real-world masking 
sounds likely to be experienced by marine mammals in the wild (e.g., 
Branstetter et al., 2013).
    Masking affects both senders and receivers of acoustic signals and 
can potentially have long-term chronic effects on marine mammals at the 
population level as well as at the individual level. Low-frequency 
ambient sound levels have increased by as much as 20 dB (more than 
three times in terms of SPL) in the world's ocean from pre-industrial 
periods, with most of the increase from distant commercial shipping 
(Hildebrand 2009). All anthropogenic sound sources, but especially 
chronic and lower-frequency signals (e.g., from vessel traffic), 
contribute to elevated ambient sound levels, thus intensifying masking.

Acoustic Effects, Underwater

    Potential Effects of Pile Driving and Removal Sound--The effects of 
sounds from pile driving and removal 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 removal 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/removal 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 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. Soft porous substrates would also 
likely require less time to drive the pile, and possibly less forceful 
equipment, which would ultimately decrease the intensity of the 
acoustic source.
    In the absence of mitigation, impacts to marine species could be 
expected to include physiological and behavioral responses to the 
acoustic signature (Viada et al., 2008). Potential effects from 
impulsive sound sources like pile driving can range in severity from 
effects such as behavioral disturbance to

[[Page 29498]]

temporary or permanent hearing impairment (Yelverton et al., 1973).
    Hearing Impairment and Other Physical Effects--Marine mammals 
exposed to high intensity sound repeatedly or for prolonged periods can 
experience hearing threshold shifts. PTS constitutes injury, but TTS 
does not (Southall et al., 2007). Based on the best scientific 
information available, the SPLs for the construction activities in this 
project are below the thresholds that could cause TTS or the onset of 
PTS (Table 5).
    Non-auditory Physiological Effects--Non-auditory physiological 
effects or injuries that theoretically might occur in marine mammals 
exposed to strong underwater sound include stress, neurological 
effects, bubble formation, resonance effects, and other types of organ 
or tissue damage (Cox et al., 2006; Southall et al., 2007). Studies 
examining such effects are limited. In general, little is known about 
the potential for pile driving or removal to cause auditory impairment 
or other physical effects in marine mammals. Available data suggest 
that such effects, if they occur at all, would presumably be limited to 
short distances from the sound source and to activities that extend 
over a prolonged period. The available data do not allow identification 
of a specific exposure level above which non-auditory effects can be 
expected (Southall et al., 2007) or any meaningful quantitative 
predictions of the numbers (if any) of marine mammals that might be 
affected in those ways. Marine mammals that show behavioral avoidance 
of pile driving, including some odontocetes and some pinnipeds, are 
especially unlikely to incur auditory impairment or non-auditory 
physical effects.

Disturbance Reactions

    Responses to continuous sound, such as vibratory pile installation, 
have not been documented as well as responses to pulsed sounds. With 
both types of pile driving, it is likely that the onset of pile driving 
could result in temporary, short term changes in an animal's typical 
behavior and/or avoidance of the affected area. These behavioral 
changes may include (Richardson et al., 1995): Changing durations of 
surfacing and dives, number of blows per surfacing, or moving direction 
and/or speed; reduced/increased vocal activities; changing/cessation of 
certain behavioral activities (such as socializing or feeding); visible 
startle response or aggressive behavior (such as tail/fluke slapping or 
jaw clapping); avoidance of areas where sound sources are located; and/
or flight responses (e.g., pinnipeds flushing into water from haul-outs 
or rookeries). Pinnipeds may increase their haul-out time, possibly to 
avoid in-water disturbance (Thorson and Reyff 2006). If a marine mammal 
responds to a stimulus by changing its behavior (e.g., through 
relatively minor changes in locomotion direction/speed or vocalization 
behavior), the response may or may not constitute taking at the 
individual level, and is unlikely to affect the stock or the species as 
a whole. However, if a sound source displaces marine mammals from an 
important feeding or breeding area for a prolonged period, impacts on 
animals, and if so potentially on the stock or species, could 
potentially be significant (e.g., Lusseau and Bejder 2007; Weilgart 
2007).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification could be expected to be biologically significant if the 
change affects growth, survival, or reproduction. Significant 
behavioral modifications that could potentially lead to effects on 
growth, survival, or reproduction include:
     Drastic changes in diving/surfacing patterns (such as 
those thought to cause beaked whale stranding due to exposure to 
military mid-frequency tactical sonar);
     Longer-term habitat abandonment due to loss of desirable 
acoustic environment; and
     Longer-term cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic sound 
depends on both external factors (characteristics of sound sources and 
their paths) and the specific characteristics of the receiving animals 
(hearing, motivation, experience, demography) and is difficult to 
predict (Southall et al., 2007).

Auditory Masking

    Natural and artificial sounds can disrupt behavior by masking. The 
frequency range of the potentially masking sound is important in 
determining any potential behavioral impacts. Because sound generated 
from in-water pile driving and removal is mostly concentrated at low 
frequency ranges, it may have less effect on high frequency 
echolocation sounds made by porpoises. The most intense underwater 
sounds in the proposed action are those produced by impact pile 
driving. Given that the energy distribution of pile driving covers a 
broad frequency spectrum, sound from these sources would likely be 
within the audible range of marine mammals present in the project area. 
Impact pile driving activity is relatively short-term, with rapid 
pulses occurring for approximately fifteen minutes per pile. The 
probability for impact pile driving resulting from this proposed action 
masking acoustic signals important to the behavior and survival of 
marine mammal species is low. Vibratory pile driving is also relatively 
short-term, with rapid oscillations occurring for approximately one and 
a half hours per pile. It is possible that vibratory pile driving 
resulting from this proposed action may mask acoustic signals important 
to the behavior and survival of marine mammal species, but the short-
term duration and limited affected area would result in insignificant 
impacts from masking. Any masking event that could possibly rise to 
Level B harassment under the MMPA would occur concurrently within the 
zones of behavioral harassment already estimated for vibratory and 
impact pile driving, and which have already been taken into account in 
the exposure analysis.
    Acoustic Effects, Airborne--Pinnipeds that occur near the project 
site could be exposed to airborne sounds associated with pile driving 
and removal that have the potential to cause behavioral harassment, 
depending on their distance from pile driving activities. Cetaceans are 
not expected to be exposed to airborne sounds that would result in 
harassment as defined under the MMPA.
    Airborne noise will primarily be an issue for pinnipeds that are 
swimming or hauled out near the project site within the range of noise 
levels elevated above the acoustic criteria. We recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with their heads above 
water. Most likely, airborne sound would cause behavioral responses 
similar to those discussed above in relation to underwater sound. For 
instance, anthropogenic sound could cause hauled-out pinnipeds to 
exhibit changes in their normal behavior, such as reduction in 
vocalizations, or cause them to temporarily abandon the area and move 
further from the source. However, these animals would previously have 
been `taken' as a result of exposure to underwater sound above the 
behavioral harassment thresholds, which are in all cases larger than 
those associated with airborne sound. Thus, the behavioral harassment 
of these animals is already accounted for in these estimates of 
potential take. Multiple instances of exposure to sound

[[Page 29499]]

above NMFS' thresholds for behavioral harassment are not believed to 
result in increased behavioral disturbance, in either nature or 
intensity of disturbance reaction. Therefore, we do not believe that 
authorization of incidental take resulting from airborne sound for 
pinnipeds is warranted, and airborne sound is not discussed further 
here.

Anticipated Effects on Habitat

    The proposed activities at the 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. Therefore, the main 
impact issue associated with the proposed activity would be temporarily 
elevated sound levels and the associated direct effects on marine 
mammals, as discussed previously in this document. The primary 
potential acoustic impacts to marine mammal habitat are associated with 
elevated sound levels produced by vibratory and impact pile driving and 
removal in the area. However, other potential impacts to the 
surrounding habitat from physical disturbance are also possible.

Pile Driving Effects on Potential Prey (Fish)

    Construction activities would produce continuous (i.e., vibratory 
pile driving sounds) and pulsed (i.e. impact driving) sounds. Fish 
react to sounds that are especially strong and/or intermittent low-
frequency sounds. Short duration, sharp sounds can cause overt or 
subtle changes in fish behavior and local distribution. Hastings and 
Popper (2005) identified several studies that suggest fish may relocate 
to avoid certain areas of sound energy. Additional studies have 
documented effects of pile driving on fish, although several are based 
on studies in support of large, multiyear bridge construction projects 
(e.g., Scholik and Yan 2001, 2002; Popper and Hastings 2009). Sound 
pulses at received levels of 160 dB may cause subtle changes in fish 
behavior. SPLs of 180 dB may cause noticeable changes in behavior 
(Pearson et al., 1992; Skalski et al., 1992). SPLs of sufficient 
strength have been known to cause injury to fish and fish mortality.
    The most likely impact to fish from pile driving activities at the 
project area would be temporary behavioral avoidance of the area. The 
duration of fish avoidance of this area after pile driving stops is 
unknown, but a rapid return to normal recruitment, distribution and 
behavior is anticipated. In general, impacts to marine mammal prey 
species are expected to be minor and temporary due to the short 
timeframe for the project.

Pile Driving Effects on Potential Foraging Habitat

    The area likely impacted by the project is relatively small 
compared to the available habitat in San Francisco Bay. Avoidance by 
potential prey (i.e., fish) of the immediate area due to the temporary 
loss of this foraging habitat is also possible. The duration of fish 
avoidance of this area after pile driving stops is unknown, but a rapid 
return to normal recruitment, distribution and behavior is anticipated. 
Any behavioral avoidance by fish of the disturbed area would still 
leave significantly large areas of fish and marine mammal foraging 
habitat in the nearby vicinity in San Francisco Bay.
    In summary, given the short daily duration of sound associated with 
individual pile driving events and the relatively small areas being 
affected, pile driving activities associated with the proposed action 
are not likely to have a permanent, adverse effect on any fish habitat, 
or populations of fish species. Thus, any impacts to marine mammal 
habitat are not expected to cause significant or long-term consequences 
for individual marine mammals or their populations.

Estimated Take by Incidental Harassment

    This section provides an estimate of the number of incidental takes 
proposed for authorization through this IHA, which will inform both 
NMFS' consideration of whether the number of takes is ``small'' and the 
negligible impact determination.
    Harassment is the only type of take expected to result from these 
activities. Except with respect to certain activities not pertinent 
here, section 3(18) of the MMPA defines ``harassment'' as: any act of 
pursuit, torment, or annoyance which (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild (Level A harassment); 
or (ii) has the potential to disturb a marine mammal or marine mammal 
stock in the wild by causing disruption of behavioral patterns, 
including, but not limited to, migration, breathing, nursing, breeding, 
feeding, or sheltering (Level B harassment).
    Authorized takes would be by Level A and Level B harassment, in the 
form of disruption of behavioral patterns for individual marine mammals 
resulting from exposure to vibratory and impact pile driving and 
removal, and potential permanent threshold shift (PTS) for harbor seals 
that may transit through the Level A zone to their haulout. Based on 
the nature of the activity and the anticipated effectiveness of the 
mitigation measures (i.e., bubble curtain, soft start, etc.--discussed 
in detail below in Proposed Mitigation section), Level A harassment is 
neither anticipated nor proposed to be authorized for all other 
species.
    As described previously, no mortality is anticipated or proposed to 
be authorized for this activity. Below we describe how the take is 
estimated.
    Described in the most basic way, we estimate take by considering: 
(1) Acoustic thresholds above which NMFS believes the best available 
science indicates marine mammals will be behaviorally harassed or incur 
some degree of permanent hearing impairment; (2) the area or volume of 
water that will be ensonified above these levels in a day; (3) the 
density or occurrence of marine mammals within these ensonified areas; 
and, (4) and the number of days of activities. Below, we describe these 
components in more detail and present the proposed take estimate.

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007, 
Ellison et al., 2011). Based on what the available science indicates 
and the practical need to use a threshold based on a factor that is 
both predictable and measurable for most activities, NMFS uses a 
generalized acoustic threshold based on received level to estimate the 
onset of behavioral harassment. NMFS predicts that marine mammals are 
likely to be behaviorally harassed in a manner we consider Level B 
harassment when exposed to

[[Page 29500]]

underwater anthropogenic noise above received levels of 120 dB re 1 
[mu]Pa (rms) for continuous (e.g. vibratory pile-driving, drilling) and 
above 160 dB re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., 
seismic airguns) or intermittent (e.g., scientific sonar) sources.
    WETA's proposed activities include the use of continuous (vibratory 
pile driving) and impulsive (impact pile driving) sources, and 
therefore the 120 and 160 dB re 1 [mu]Pa (rms) are applicable.
    Level A harassment for non-explosive sources--NMFS' Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (Technical Guidance 2016) identifies dual criteria to 
assess auditory injury (Level A harassment) to five different marine 
mammal groups (based on hearing sensitivity) as a result of exposure to 
noise from two different types of sources (impulsive or non-impulsive). 
WETA's proposed activity includes the use of impulsive (impact pile 
driving) and non-impulsive (vibratory pile driving) sources.
    These thresholds were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers to inform the final product, and are 
provided in the table below. The references, analysis, and methodology 
used in the development of the thresholds are described in NMFS 2016 
Technical Guidance, which may be accessed at: https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

                     Table 4--Thresholds Identifying the Onset of Permanent Threshold Shift
----------------------------------------------------------------------------------------------------------------
                                                   PTS onset acoustic thresholds *  (received level)
            Hearing group             --------------------------------------------------------------------------
                                              Impulsive                           Non-impulsive
----------------------------------------------------------------------------------------------------------------
Low-frequency cetaceans..............  Cell 1: Lpk,flat: 219    Cell 2: LI,LE,LF,24h: 199 dB.
                                        dB; LE,LF,24h: 183 dB.
Mid-frequency cetaceans..............  Cell 3: Lpk,flat: 230    Cell 4: LE,MF,24h: 198 dB.
                                        dB; LE,MF,24h: 185 dB.
High-frequency cetaceans.............  Cell 5: Lpk,flat: 202    Cell 6: LE,HF,24h: 173 dB.
                                        dB; LE,HF,24h: 155 dB.
Phocid Pinnipeds (underwaters).......  Cell 7: Lpk,flat: 218    Cell 8: LE,PW,24h: 201 dB.
                                        dB; LE,PW,24h: 185 dB.
Otariid Pinnipeds (underwater).......  Cell 9: Lpk,flat: 232    Cell 10: LE,OW,24h: 219 dB.
                                        dB; LE,OW,24h: 203 dB.
----------------------------------------------------------------------------------------------------------------
\1\ NMFS 2016.

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds.
    Pile driving and removal 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, such 
as at the Central Bay operations and maintenance facility, 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. Practical 
spreading loss (4.5 dB reduction in sound level for each doubling of 
distance) is assumed here.
    Underwater Sound--The intensity of pile driving and removal sounds 
is greatly influenced by factors such as the type of piles, hammers, 
and the physical environment in which the activity takes place. A 
number of studies, primarily on the west coast, have measured sound 
produced during underwater pile driving projects. These data are 
largely for impact driving of steel pipe piles and concrete piles as 
well as vibratory driving of steel pipe piles.
    In order to determine reasonable source levels and their associated 
effects on marine mammals that are likely to result from vibratory or 
impact pile driving or removal at the Project area, we considered 
existing measurements from similar physical environments (e.g. 
substrate of bay mud and water depths ranging from 14 to 38 ft).

Level A Isopleths (Table 5)

    The values used to calculate distances at which sound would be 
expected to exceed the Level A thresholds for impact driving of and 36 
in and 42 in piles include peak values of 185 dB and anticipated SELs 
for unattenuated impact pile-driving of 175 dB, and peak values of 193 
dB and SEL values of 167 for 24 in piles (Caltrans 2015a). Bubble 
curtains will be used during the installation of these piles, which is 
expected to reduce noise levels by about 10 dB rms (Caltrans 2015a), 
which are the values used in Table 5. Vibratory driving source levels 
include 175 dB RMS for 42-in piles, 170 dB RMS for 36-in piles, 165 dB 
RMS for 24 in piles, and 150 dB RMS for 14 in H piles (Caltrans 2015a). 
The inputs for the user spreadsheet from NMFS' Guidance are as follows: 
For impact driving, 450 strikes per pile with 3 piles per day for 24 in 
piles, and 600 strikes per pile with 2 piles per day for 36 in and 42 
in piles. The total duration for vibratory driving of 14-in, 24-in, 36-
in, and 42-in piles were all approximately 10 minutes (0.166666, 
0.1708333 hours, 0.16666 hours, and 0.177777 hours, respectively).

[[Page 29501]]



               Table 5--Expected Pile-Driving Noise Levels and Distances of Level A Threshold Exceedance With Impact and Vibratory Driver
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                    Source  levels at  10 meters  (dB)               Distance to level A threshold in meters
                                                 -------------------------------------------------------------------------------------------------------
   Project element requiring pile installation                                                                         LF *         MF *         HF *
                                                    Peak \1\       SEL          RMS        Phocids      Otariids    Cetaceans    Cetaceans    Cetaceans
--------------------------------------------------------------------------------------------------------------------------------------------------------
42 in steel piles--Vibratory Driver.............  ...........  ...........          175         11.3          0.8         18.5          1.6         27.4
42 in steel piles--Impact Driver (BCA)\1\.......          200          173  ...........          130          9.5          243          8.6        289.4
36-Inch Steel Piles--Vibratory Driver...........  ...........  ...........          170            5          0.4          8.2          0.7         12.2
36-Inch Steel Piles--Impact Driver (BCA)\1\.....          200          173  ...........          130          9.5          243          8.6        289.4
24-Inch Steel Piles--Vibratory Driver...........  ...........  ...........          160          1.1          0.1          1.8          0.2          2.7
24-Inch Steel Piles--Impact Driver (BCA) \1\....      193 \2\      167 \2\  ...........           56          4.1        104.6          3.7        124.6
14 in H-piles--Vibratory Driver.................  ...........  ...........          150          0.2            0          0.4            0          0.6
14 in H-piles Vibratory Extraction..............  ...........  ...........          150          0.2            0          0.4            0          0.6
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Low frequency (LF) cetaceans, Mid frequency (MF) cetaceans, High frequency (HF) cetaceans.
\1\ Bubble curtain attenuation (BCA). A bubble curtain will be used for impact driving and is assumed to reduce the source level by 10dB. Therefore,
  source levels were reduced by this amount for take calculations.

Level B Isopleths (Table 6)

    Approximately 15 steel piles, 42-in in diameter, will be installed, 
with approximately 2 installed per day over 8 days. The source level 
for this pile size during impact driving came from the Caltrans summary 
table (Caltrans 2015a) for 36 in piles at approximately 10 m depth. The 
source level for this pile size during vibratory driving came from the 
Caltrans summary table for the ``loudest values'' for 36 in piles.
    Approximately 6 steel piles, 36-in in diameter, will be installed, 
with approximately 2 installed per day over 3 days. The source level 
for this pile size during impact driving came from the Caltrans summary 
table (Caltrans 2015a) for 36 in piles at approximately 10 m depth. The 
source level for this pile size during vibratory driving came from the 
Caltrans summary table for the ``typical values'' for 36 in piles.
    Approximately 8 steel piles, 24-in in diameter, will be installed, 
with approximately 3 installed per day over 3 days. The source level 
for this pile size during impact driving came from the Caltrans summary 
table (Caltrans 2015a) for 24 in piles at approximately 5 m depth. The 
source level for this pile size during vibratory driving came from the 
Caltrans table for the Trinidad Pier Reconstruction project (Caltrans 
2015a).
    Approximately 20 14-in H piles (10 temporary and 10 permanent), 
with approximately 5 installed or removed per day over 8 days. The 
source level for this pile size during impact and vibratory driving 
came from the Caltrans summary table (Caltrans 2015a) for 10 in H 
piles.
    Tables 6 and 7 show the expected underwater sound levels for pile 
driving activities and the estimated distances to the Level A (Table 5) 
and Level B (Table 6) thresholds.
    When NMFS Technical Guidance (2016) was published, in recognition 
of the fact that ensonified area/volume could be more technically 
challenging to predict because of the duration component in the new 
thresholds, we developed a User Spreadsheet that includes tools to help 
predict a simple isopleth that can be used in conjunction with marine 
mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which will result in some degree of 
overestimate of Level A take. However, these tools offer the best way 
to predict appropriate isopleths when more sophisticated 3D-modeling 
methods are not available, and NMFS continues to develop ways to 
quantitatively refine these tools, and will qualitatively address the 
output where appropriate. For stationary sources (such as WETA's 
Project), NMFS User Spreadsheet predicts the closest distance at which, 
if a marine mammal remained at that distance the whole duration of the 
activity, it would not incur PTS. Inputs used in the User Spreadsheet, 
and the resulting isopleths are reported below.

    Table 6--Expected Pile-Driving Noise Levels and Distances of Level B Threshold Exceedance With Impact and
                                                Vibratory Driver
----------------------------------------------------------------------------------------------------------------
                                                                                    Distance to       Area of
                                                                                      level B        potential
                                                                   Source levels   threshold, in      level B
                                                                   at 10 meters       meters         threshold
           Project element requiring pile installation             (33 feet) (dB ---------------- exceedance (in
                                                                       rms)       160/120 dB RMS      square
                                                                                    (level B) 2    kilometers) 1
 
----------------------------------------------------------------------------------------------------------------
42 in steel piles--Vibratory Driver.............................             175          46,416           12.97
42 in steel piles--Impact Driver (BCA) 1........................           1 200             341            0.27

[[Page 29502]]

 
36-Inch Steel Piles--Vibratory Driver...........................             170          21,544           12.97
36-Inch Steel Piles--Impact Driver (BCA) 1......................           1 200             341            0.27
24-Inch Steel Piles--Vibratory Driver...........................             160           4,642            4.92
24-Inch Steel Piles--Impact Driver (BCA) 1......................           1 193             215            0.13
14-Inch H Piles--Vibratory Driver...............................             150           1,000            1.01
14-Inch H Piles--Vibratory Extraction...........................             150           1,000            1.01
----------------------------------------------------------------------------------------------------------------
1 For underwater noise, the Level B harassment (disturbance) threshold is 160 dB for impulsive noise and 120 dB
  for continuous noise.
2 Bubble curtain attenuation (BCA). A bubble curtain will be used for impact driving and is expected to reduce
  the source level by 10dB.

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.
    At-sea densities for marine mammal species have been determined for 
harbor seals and California sea lions in San Francisco Bay based on 
marine mammal monitoring by Caltrans for the San Francisco-Oakland Bay 
Bridge Project from 2000 to 2015 (Caltrans 2016); all other estimates 
here are determined by using observational data taken during marine 
mammal monitoring associated with the Richmond-San Rafael Bridge 
retrofit project, the San Francisco-Oakland Bay Bridge (SFOBB), which 
has been ongoing for the past 15 years, and anecdotal observational 
reports from local entities.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    All estimates are conservative and include the following 
assumptions:
     All pilings installed at each site would have an 
underwater noise disturbance equal to the piling that causes the 
greatest noise disturbance (i.e., the piling farthest from shore) 
installed with the method that has the largest zone of influence (ZOI). 
The largest underwater disturbance (Level B) ZOI would be produced by 
vibratory driving steel piles; therefore take estimates were calculated 
using the vibratory pile-driving ZOIs. The ZOIs for each threshold are 
not spherical and are truncated by land masses on either side of the 
project area, which would dissipate sound pressure waves.
     Exposures were based on an estimated total of 22 work 
days. Each activity ranges in amount of days needed to be completed 
(Table 1).
     In the absence of site specific underwater acoustic 
propagation modeling, the practical spreading loss model was used to 
determine the ZOI.
     All marine mammal individuals potentially available are 
assumed to be present within the relevant area, and thus incidentally 
taken;
     An individual can only be taken once during a 24-hour 
period; and,
     Exposures to sound levels at or above the relevant 
thresholds equate to take, as defined by the MMPA.
    The estimation of marine mammal takes typically uses the following 
calculation:
    For California sea lions: Level B exposure estimate = D (density) * 
Area of ensonification * Number of days of noise generating activities.
    For harbor seals: Level B exposure estimate = ((D * area of 
ensonification) + 15) * number of days of noise generating activities.
    For all other marine mammal species: Level B exposure estimate = N 
(number of animals) in the area * Number of days of noise generating 
activities.
    To account for the increase in California sea lion density due to 
El Ni[ntilde]o, the daily take estimated from the observed density has 
been increased by a factor of 10 for each day that pile driving or 
removal occurs.
    There are a number of reasons why estimates of potential instances 
of take may be overestimates of the number of individuals taken, 
assuming that available density or abundance estimates and estimated 
ZOI areas are accurate. We assume, in the absence of information 
supporting a more refined conclusion, that the output of the 
calculation represents the number of individuals that may be taken by 
the specified activity. In fact, in the context of stationary 
activities such as pile driving and in areas where resident animals may 
be present, this number represents the number of instances of take that 
may accrue to a smaller number of individuals, with some number of 
animals being exposed more than once per individual. While pile driving 
and removal can occur any day throughout the in-water work window, and 
the analysis is conducted on a per day basis, only a fraction of that 
time (typically a matter of hours on any given day) is actually spent 
pile driving/removal. The potential effectiveness of mitigation 
measures in reducing the number of takes is typically not quantified in 
the take estimation process. For these reasons, these take estimates 
may be conservative, especially if each take is considered a separate 
individual animal, and especially for pinnipeds.

Description of Marine Mammals in the Area of the Specified Activity

Harbor Seals
    Monitoring of marine mammals in the vicinity of the SFOBB has been 
ongoing for 15 years; from those data, Caltrans has produced at-sea 
density estimates for Pacific harbor seal of 0.83 animals per square 
kilometer for the fall season (Caltrans 2016). Since the construction 
of the new pier that is currently being used as a haul out for harbor 
seals, there are additional seals that need to be taken into account 
for the take calculation. The average number of seals that use the 
haulout at any given time is 15 animals; therefore, we would add an 
additional 15 seals per day. Using this density and the additional 15 
animals per day, the potential average daily take for the areas over 
which the Level B harassment thresholds may be exceeded are estimated 
in Table 7.

[[Page 29503]]



                                    Table 7--Take Calculation for Harbor Seal
----------------------------------------------------------------------------------------------------------------
                                                                                  Number of days
           Activity                Pile type         Density       Area (km\2\)     of activity    Take estimate
----------------------------------------------------------------------------------------------------------------
Vibratory driving............  36-in and 42-in   0.83 animal/              12.97            3; 8         77; 206
                                steel pile.       km\2\.
Vibratory driving............  24-in steel pile  0.83 animal/               4.92               3              57
                                                  km\2\.
Vibratory driving and removal  14-in steel H     0.83 animal/               1.01               8             127
                                piles.            km\2\.
----------------------------------------------------------------------------------------------------------------

    A total of 467 harbor seal takes are estimated for 2017 (Table 9). 
Because seals may traverse the Level A zone when going to and from the 
healout that is approximately 300 m from the project area, it would not 
be practicable to shutdown every time. Therefore 18 Level A takes are 
requested for this species by assuming 1.6 harbor seals per day over 11 
days of impact driving of 36 in and 42 in piles may enter the zone (see 
the Description of Marine Mammals in the Area of the Specified Activity 
for information on seal occurrence per day). While the Level A zone is 
relatively large for this hearing group (approximately 290 m), there 
will be 2 MMOs monitoring the zone in the most advantageous locations 
to spot marine mammals to initiate a shutdown to avoid take by Level A 
harassment.
California Sea Lion
    Monitoring of marine mammals in the vicinity of the SFOBB has been 
ongoing for 15 years; from those data, Caltrans has produced at-sea 
density estimates for California sea lion of 0.09 animal per square 
kilometer for the post-breeding season (Caltrans 2016). Using this 
density, the potential average daily take for the areas over which the 
Level B harassment thresholds may be exceeded is estimated in Table 8.

                                Table 8--Take Calculation for California Sea Lion
----------------------------------------------------------------------------------------------------------------
                                                                                  Number of days   Take Estimate
           Activity                Pile type         Density       Area (km\2\)     of activity     [supcaret]
----------------------------------------------------------------------------------------------------------------
Vibratory driving............  36-in and 42-in   0.09 animal/              12.97            3; 8          35; 93
                                steel pile.       km\2\.
Vibratory driving............  24-in steel pile  0.09 animal/               4.92               3              13
                                                  km\2\.
Vibratory driving............  14-in steel H     0.09 animal/               1.01               8               7
                                piles.            km\2\.
----------------------------------------------------------------------------------------------------------------
* All California sea lion estimates were multiplied by 10 to account for the increased occurrence of this
  species due to El Ni[ntilde]o.
[supcaret] Total take number is 149, not 148 because we round at the end, whereas here, it shows rounding per
  day.

    All California sea lion estimates were multiplied by 10 to account 
for the increased occurrence of this species due to El Ni[ntilde]o. A 
total of 149 California sea lion takes is estimated for 2017 (Table 9). 
Level A take is not expected for California sea lion based on area of 
ensonification and density of the animals in that area.
Northern Elephant Seal
    Monitoring of marine mammals in the vicinity of the SFOBB has been 
ongoing for 15 years; from those data, Caltrans has produced an 
estimated at-sea density for northern elephant seal of 0.03 animal per 
square kilometer (Caltrans 2016). Most sightings of northern elephant 
seal in San Francisco Bay occur in spring or early summer, and are less 
likely to occur during the periods of in-water work for this project 
(June through November). As a result, densities during pile driving and 
removal for the proposed action would be much lower. Therefore, we 
estimate that it is possible that a lone northern elephant seal may 
enter the Level B harassment area once per week during pile driving or 
removal, for a total of 18 takes in 2017 (Table 9). Level A take of 
Northern elephant seal is not requested, nor is it proposed to be 
authorized because although one animal may approach the large Level B 
zones, it is not expected that it will continue in the area of 
ensonification into the Level A zone. Further, if the animal does 
approach the Level A zone, construction will be shut down.
Northern Fur Seal
    During the breeding season, the majority of the worldwide 
population is found on the Pribilof Islands in the southern Bering Sea, 
with the remaining animals spread throughout the North Pacific Ocean. 
On the coast of California, small breeding colonies are present at San 
Miguel Island off southern California, and the Farallon Islands off 
central California (Carretta et al., 2014). Northern fur seal are a 
pelagic species and are rarely seen near the shore away from breeding 
areas. Juveniles of this species occasionally strand in San Francisco 
Bay, particularly during El Ni[ntilde]o events, for example, during the 
2006 El Ni[ntilde]o event, 33 fur seals were admitted to the Marine 
Mammal Center (TMMC 2016). Some of these stranded animals were 
collected from shorelines in San Francisco Bay. Due to the recent El 
Ni[ntilde]o event, northern fur seals were observed in San Francisco 
bay more frequently, as well as strandings all along the California 
coast and inside San Francisco Bay (TMMC, personal communication); a 
trend that may continue this summer through winter if El Ni[ntilde]o 
conditions occur. Because sightings are normally rare; instances 
recently have been observed, but are not common, and based on estimates 
from local observations (TMMC, personal communication), it is estimated 
that ten northern fur seals will be taken in 2017 (Table 9). Level A 
take is not requested or proposed to be authorized for this species.
Harbor Porpoise
    In the last six decades, harbor porpoises were observed outside of 
San Francisco Bay. The few harbor porpoises that entered were not 
sighted past central Bay close to the Golden Gate Bridge. In recent 
years, however, there have been increasingly common observations of 
harbor porpoises in central, north, and south San Francisco Bay. 
Porpoise activity inside San Francisco Bay is thought to be related to 
foraging and mating behaviors (Keener 2011; Duffy 2015). According to 
observations by the Golden Gate Cetacean Research team as part of their 
multi-year assessment, over 100

[[Page 29504]]

porpoises may be seen at one time entering San Francisco Bay; and over 
600 individual animals are documented in a photo-ID database. However, 
sightings are concentrated in the vicinity of the Golden Gate Bridge 
and Angel Island, north of the project area, with lesser numbers 
sighted south of Alcatraz and west of Treasure Island (Keener 2011). 
Harbor porpoise generally travel individually or in small groups of two 
or three (Sekiguchi 1995).
    Monitoring of marine mammals in the vicinity of the SFOBB has been 
ongoing for 15 years; from those data, Caltrans has produced an 
estimated at-sea density for harbor porpoise of 0.021 animal per square 
kilometer (Caltrans 2016). However, this estimate would be an 
overestimate of what would actually be seen in the project area since 
it is a smaller area than the monitoring area of SFOBB. In order to 
estimate a more realistic take number, we assume it is possible that a 
small group of individuals (five harbor porpoises) may enter the Level 
B harassment area on as many as two days of pile driving or removal, 
for a total of ten harbor porpoise takes per year (Table 9). It is 
possible that harbor porpoise may enter the Level A harassment zone for 
high frequency cetaceans; however, 2 MMOs will be monitoring the area 
and WETA would implement a shutdown for the entire zone if a harbor 
porpoise (or any other marine mammal) approaches the Level A zone; 
therefore Level A take is not being requested, nor authorized for this 
species.
Gray Whale
    Historically, gray whales were not common in San Francisco Bay. The 
Oceanic Society has tracked gray whale sightings since they began 
returning to San Francisco Bay regularly in the late 1990s. The Oceanic 
Society data show that all age classes of gray whales are entering San 
Francisco Bay, and that they enter as singles or in groups of up to 
five individuals. However, the data do not distinguish between 
sightings of gray whales and number of individual whales (Winning 
2008). 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 specific years were 
unreported). It is estimated that two to six gray whales enter San 
Francisco Bay in any given year. Because construction activities are 
only occurring during a maximum of 22 days in 2017, it is estimated 
that two gray whales may potentially enter the area during the 
construction period, for a total of 2 gray whale takes in 2017 (Table 
9).
Bottlenose Dolphin
    Since the 1982-83 El Ni[ntilde]o, which increased water 
temperatures off California, bottlenose dolphins have been consistently 
sighted along the central California coast (Carretta et al., 2008). The 
northern limit of their regular range is currently the Pacific coast 
off San Francisco and Marin County, and they occasionally enter San 
Francisco Bay, sometimes foraging for fish in Fort Point Cove, just 
east of the Golden Gate Bridge. Members of this stock are transient and 
make movements up and down the coast, and into some estuaries, 
throughout the year. Bottlenose dolphins are being observed in San 
Francisco bay more frequently in recent years (TMMC, personal 
communication). Groups with an average group size of five animals enter 
the bay and occur near Yerba Buena Island once per week for a two week 
stint and then depart the bay (TMMC, personal communication). Assuming 
groups of five individuals may enter San Francisco Bay approximately 
three times during the construction activities, and may enter the 
ensonified area once per week over the two week stint, for a total of 
30 takes of bottlenose dolphins. Additionally, in the summer of 2015, a 
lone bottlenose dolphin was seen swimming in the Oyster Point area of 
South San Francisco (GGCR 2016). We estimate that this lone bottlenose 
dolphin may be present in the project area each day of construction, an 
additional 22 takes. The 30 takes for a small group, and the 22 takes 
for the lone bottlenose dolphin equate to 52 bottlenose dolphin takes 
for 2017 (Table 9).

                                                  Table 9--Calculations for Incidental Take Estimation
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                          Estimated take by Level B harassment
                                                   Number of  ------------------------------------------------------------------------------------------
           Pile type            Pile-driver type    driving                                Northern      Harbor                   Northern
                                                      days     Harbor seal  CA sea lion    elephant     porpoise    Gray whale    fur seal    Bottlenose
                                                                                \1\        seal \2\       \2\          \2\          \2\        dolphin
--------------------------------------------------------------------------------------------------------------------------------------------------------
42-in steel pile..............  Vibratory \3\...            8           77           35           NA           NA           NA           NA            8
36-in steel...................  Vibratory \3\...            3          206           93           NA           NA           NA           NA            3
24-in steel piles.............  Vibratory \3\...            3           57           13           NA           NA           NA           NA            3
14-in steel H pile............  Vibratory.......            8          127            7           NA           NA           NA           NA            8
                                                 -------------------------------------------------------------------------------------------------------
Project Total (2017)..........  ................           22          467   [supcaret]       \2\ 18       \2\ 10        \2\ 2       \2\ 10         * 52
                                                                                    149
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ To account for potential El Ni[ntilde]o conditions, take calculated from at-sea densities for California sea lion has been increased by a factor of
  10.
\2\ Take is not calculated by activity type for these species with a low potential to occur, only a yearly total is given.
\3\ Piles of this type may also be installed with an impact hammer, which would reduce the estimated take.
* Total take includes an additional 30 takes to account for a transitory group of dolphins that may occur in the project area over the course of the
  project.
[supcaret] Total take number is 149, not 148 because we round at the end, whereas here, it shows rounding per day.

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

[[Page 29505]]

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 balance 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--
which considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range), as well as the likelihood that 
the measure will be effective if implemented; and the likelihood of 
effective implementation, and;
    (2) the practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    Measurements from similar pile driving events were coupled with 
practical spreading loss to estimate zones of influence (ZOI; see 
Estimated Take by Incidental Harassment); these values were used to 
develop mitigation measures for pile driving and removal activities at 
the Project area. The ZOIs effectively represent the mitigation zone 
that would be established around each pile to prevent Level A 
harassment to marine mammals, while providing estimates of the areas 
within which Level B harassment might occur. In addition to the 
specific measures described later in this section, WETA would conduct 
briefings between construction supervisors and crews, marine mammal 
monitoring team, and WETA staff prior to the start of all pile driving 
activity, and when new personnel join the work, in order to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures.

Monitoring and Shutdown for Construction Activities

    The following measures would apply to WETA's mitigation through 
shutdown and disturbance zones:
    Shutdown Zone--For all pile driving activities, WETA will establish 
a shutdown zone intended to contain the area in which SPLs equal or 
exceed the auditory injury criteria for cetaceans and pinnipeds. The 
purpose of a shutdown zone is to define an area within which shutdown 
of activity would occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area), thus preventing 
injury of marine mammals (as described previously under Potential 
Effects of the Specified Activity on Marine Mammals, serious injury or 
death are unlikely outcomes even in the absence of mitigation 
measures). Modeled radial distances for shutdown zones are shown in 
Table 5. However, a minimum shutdown zone of 30 m will be established 
during all pile driving activities, regardless of the estimated zone.
    Disturbance Zone--Disturbance zones are the areas in which SPLs 
equal or exceed 160 and 120 dB rms (for impulse and continuous sound, 
respectively). Disturbance 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 greater detail later (see Proposed 
Monitoring and Reporting). Nominal radial distances for disturbance 
zones are shown in Table 6.
    Given the size of the disturbance zone for vibratory pile driving, 
it is impossible to guarantee that all animals would be observed or to 
make comprehensive observations of fine-scale behavioral reactions to 
sound, and only a portion of the zone (e.g., what may be reasonably 
observed by visual observers stationed within the turning basin) would 
be observed. In order to document observed instances of harassment, 
monitors record all marine mammal observations, regardless of location. 
The observer's location, as well as the location of the pile being 
driven, is known from a GPS. The location of the animal is estimated as 
a distance from the observer, which is then compared to the location 
from the pile. It may then be estimated whether the animal was exposed 
to sound levels constituting incidental harassment on the basis of 
predicted distances to relevant thresholds in post-processing of 
observational and acoustic data, and a precise accounting of observed 
incidences of harassment created. This information may then be used to 
extrapolate observed takes to reach an approximate understanding of 
actual total takes.
    Monitoring Protocols--Monitoring would be conducted before, during, 
and after pile driving and vibratory removal activities. In addition, 
observers shall record all instances of marine mammal occurrence, 
regardless of distance from activity, and shall document any behavioral 
reactions in concert with distance from piles being driven. 
Observations made outside the shutdown zone will not result in 
shutdown; that pile segment would be completed without cessation, 
unless the animal approaches or enters the shutdown zone, at which 
point all pile driving activities would be halted. Monitoring will take 
place from 30 minutes prior to initiation through thirty minutes post-
completion of pile driving and removal activities. Pile driving 
activities include the time to install or remove a single pile or 
series of piles, as long as the time elapsed between uses of the pile 
driving equipment is no more than 30 minutes. Please see the Monitoring 
Plan (www.nmfs.noaa.gov/pr/permits/incidental/construction.htm), 
developed by WETA in agreement with NMFS, for full details of the 
monitoring protocols.
    The following additional measures apply to visual monitoring:
    (1) Monitoring will be conducted by qualified observers, who will 
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. A minimum of two 
observers will be required for all pile driving/removal activities. 
Marine Mammal Observer (MMO) requirements for construction actions are 
as follows:
    (a) Independent observers (i.e., not construction personnel) are 
required;
    (b) At least one observer must have prior experience working as an 
observer;
    (c) Other observers (that do not have prior experience) may 
substitute education (undergraduate degree in biological science or 
related field) or training for experience;
    (d) Where a team of three or more observers are required, one 
observer

[[Page 29506]]

should be designated as lead observer or monitoring coordinator. The 
lead observer must have prior experience working as an observer; and
    (e) NMFS will require submission and approval of observer CVs.
    (2) Qualified MMOs are trained biologists, and need the following 
additional minimum qualifications:
    (a) 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;
    (b) Ability to conduct field observations and collect data 
according to assigned protocols;
    (c) Experience or training in the field identification of marine 
mammals, including the identification of behaviors;
    (d) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    (e) 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 and times when in-water construction activities were 
suspended to avoid potential incidental injury from construction sound 
of marine mammals observed within a defined shutdown zone; and marine 
mammal behavior; and
    (f) 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.
    (3) Prior to the start of pile driving activity, the shutdown zone 
will be monitored for thirty minutes to ensure that it is clear of 
marine mammals. Pile driving will only commence once observers have 
declared the shutdown zone clear of marine mammals; animals will be 
allowed to remain in the shutdown zone (i.e., must leave of their own 
volition) and their behavior will be monitored and documented. The 
shutdown zone may only be declared clear, and pile driving started, 
when the entire shutdown zone is visible (i.e., when not obscured by 
dark, rain, fog, etc.). In addition, if such conditions should arise 
during impact pile driving that is already underway, the activity would 
be halted.
    (4) If a marine mammal approaches or enters the shutdown zone 
during the course of pile driving operations, activity will be halted 
and delayed until either the animal has voluntarily left and been 
visually confirmed beyond the shutdown zone or fifteen minutes have 
passed without re-detection of small cetaceans and pinnipeds, and 
thirty minutes for gray whales. Monitoring will be conducted throughout 
the time required to drive a pile.
    (5) Using delay and shut-down procedures, if a species for which 
authorization has not been granted (including but not limited to 
Guadalupe fur seals and humpback whales) or if a species for which 
authorization has been granted but the authorized takes are met, 
approaches or is observed within the Level B harassment zone, 
activities will shut down immediately and not restart until the animals 
have been confirmed to have left the area.

Soft Start

    The use of a soft start procedure is believed to provide additional 
protection to marine mammals by warning or providing a chance to leave 
the area prior to the hammer operating at full capacity, and typically 
involves a requirement to initiate sound from the hammer at reduced 
energy followed by a waiting period. This procedure is repeated two 
additional times. It is difficult to specify the reduction in energy 
for any given hammer because of variation across drivers and, for 
impact hammers, the actual number of strikes at reduced energy will 
vary because operating the hammer at less than full power results in 
``bouncing'' of the hammer as it strikes the pile, resulting in 
multiple ``strikes.'' For impact driving, we require an initial set of 
three strikes from the impact hammer at reduced energy, followed by a 
30-second waiting period, then two subsequent 3 strike sets. Soft start 
will be required at the beginning of each day's impact pile driving 
work and at any time following a cessation of impact pile driving of 30 
minutes or longer.

Sound Attenuation Devices

    Two types of sound attenuation devices would be used during impact 
pile-driving: Bubble curtains and pile cushions. WETA would employ the 
use of a bubble curtain during impact pile-driving, which is assumed to 
reduce the source level by 10 dB. WETA would also employ the use of 12-
inch-thick wood cushion block on impact hammers to attenuate underwater 
sound levels.
    We have carefully evaluated WETA's proposed mitigation measures and 
considered their effectiveness in past implementation to preliminarily 
determine whether they are likely to effect the least practicable 
impact on the affected marine mammal species and stocks and their 
habitat.
    Any mitigation measure(s) we prescribe should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    (1) Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal);
    (2) A reduction in the number (total number or number at 
biologically important time or location) of individual marine mammals 
exposed to stimuli expected to result in incidental take (this goal may 
contribute to 1, above, or to reducing takes by behavioral harassment 
only);
    (3) A reduction in the number (total number or number at 
biologically important time or location) of times any individual marine 
mammal would be exposed to stimuli expected to result in incidental 
take (this goal may contribute to 1, above, or to reducing takes by 
behavioral harassment only);
    (4) A reduction in the intensity of exposure to stimuli expected to 
result in incidental take (this goal may contribute to 1, above, or to 
reducing the severity of behavioral harassment only);
    (5) Avoidance or minimization of adverse effects to marine mammal 
habitat, paying particular attention to the prey base, blockage or 
limitation of passage to or from biologically important areas, 
permanent destruction of habitat, or temporary disturbance of habitat 
during a biologically important time; and
    (6) For monitoring directly related to mitigation, an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on our evaluation of WETA's proposed measures, as well as any 
other potential measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means of 
effecting the least practicable impact on marine mammal 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

[[Page 29507]]

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 to 
both compliance and ensuring that the most value is obtained from the 
required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species in action area (e.g., 
presence, abundance, distribution, density);
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
affected species (e.g., life history, dive patterns); (3) co-occurrence 
of marine mammal species with the action; or (4) biological or 
behavioral context of exposure (e.g., age, calving or feeding areas);
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or cumulative impacts from multiple stressors;
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of individual marine mammals; or (2) 
population, species, or stock;
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat); and
     Mitigation and monitoring effectiveness.
    WETA's proposed monitoring and reporting is also described in their 
Marine Mammal Monitoring Plan, on the Internet at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.

Visual Marine Mammal Observations

    WETA will collect sighting data and behavioral responses to 
construction for marine mammal species observed in the region of 
activity during the period of activity. All marine mammal observers 
(MMOs) will be trained in marine mammal identification and behaviors 
and are required to have no other construction-related tasks while 
conducting monitoring. A minimum of two MMOs will be required for all 
pile driving/removal activities. WETA will monitor the shutdown zone 
and disturbance zone before, during, and after pile driving, with 
observers located at the best practicable vantage points. Based on our 
requirements, WETA would implement the following procedures for pile 
driving and removal:
     MMOs would be located at the best vantage point(s) in 
order to properly see the entire shutdown zone and as much of the 
disturbance zone as possible;
     During all observation periods, observers will use 
binoculars and the naked eye to search continuously for marine mammals;
     If the shutdown zones are obscured by fog or poor lighting 
conditions, pile driving at that location will not be initiated until 
that zone is visible. Should such conditions arise while impact driving 
is underway, the activity would be halted; and
     The shutdown and disturbance zones around the pile will be 
monitored for the presence of marine mammals before, during, and after 
any pile driving or removal activity.
    Individuals implementing the monitoring protocol will assess its 
effectiveness using an adaptive approach. The monitoring biologists 
will use their best professional judgment throughout implementation and 
seek improvements to these methods when deemed appropriate. Any 
modifications to protocol will be coordinated between NMFS and WETA.
    In additions, the MMO(s) will survey the potential Level A and 
nearby Level B harassment zones (areas within approximately 2,000 feet 
of the pile-driving area observable from the shore) on 2 separate 
days--no earlier than 7 days before the first day of construction--to 
establish baseline observations. Special attention will be given to the 
harbor seal haul-out sites in proximity to the project (i.e., the 
harbor seal platform and Breakwater Island). Monitoring will be timed 
to occur during various tides (preferably low and high tides) during 
daylight hours from locations that provide the best vantage point 
available, including the pier, breakwater, and adjacent docks within 
the harbor. The information collected from baseline monitoring will be 
used for comparison with results of monitoring during pile-driving 
activities.

Data Collection

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

Hydroacousting Monitoring

    The monitoring will be done in accordance with the methodology 
outlined in this Hydroacoustic Monitoring Plan (see Appendix B of 
WETA's application for more information on this Plan, including the 
methodology, equipment, and reporting information). The monitoring is 
based on dual metric criteria that will include: The following:
     Establish the distance to the 206-dB peak sound pressure 
criteria;
     Verify the extent of Level A harassment zones for marine 
mammals; and
     Verify the attenuation provided by bubble curtains.
     Provide all monitoring data to NMFS.

Reporting

    A draft report would be submitted to NMFS within 90 days of the 
completion of marine mammal monitoring, or sixty days prior to the 
requested date of issuance of any future IHA for projects at the same 
location, whichever comes first. The report will include marine mammal 
observations pre-activity, during-activity, and post-activity during 
pile driving and removal days, and will also provide descriptions of 
any behavioral responses to construction activities by marine mammals 
and a complete description of all mitigation

[[Page 29508]]

shutdowns and the results of those actions and an extrapolated total 
take estimate based on the number of marine mammals observed during the 
course of construction. A final report must be submitted within 30 days 
following resolution of comments on the draft report.

Negligible Impact Analysis and Determinations

    NMFS has defined negligible impact as an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes alone is not enough 
information on which to base an impact determination. In addition to 
considering estimates of the number of marine mammals that might be 
``taken'' through harassment, NMFS considers other factors, such as the 
likely nature of any responses (e.g., intensity, duration), the context 
of any responses (e.g., critical reproductive time or location, 
migration), as well as effects on habitat, and the likely effectiveness 
of the mitigation. We also assess the number, intensity, and context of 
estimated takes by evaluating this information relative to population 
status. Consistent with the 1989 preamble for NMFS's implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into this 
analysis via their impacts on the environmental baseline (e.g., as 
reflected in the regulatory status of the species, population size and 
growth rate where known, ongoing sources of human-caused mortality, or 
ambient noise levels).
    Pile driving and removal activities associated with the facility 
construction project, as outlined previously, have the potential to 
disturb or displace marine mammals. Specifically, the specified 
activities may result in take, in the form of Level A and Level B 
harassment (PTS and behavioral disturbance), from underwater sounds 
generated from pile driving and removal. Potential takes could occur if 
individuals of these species are present in the ensonified zone when 
pile driving and removal occurs.
    No injury, serious injury, or mortality is anticipated given the 
nature of the activities and measures designed to minimize the 
possibility of injury to marine mammals. The potential for these 
outcomes is minimized through the construction method and the 
implementation of the planned mitigation measures. Specifically, 
vibratory hammers will be the primary method of installation (impact 
driving is included only as a contingency). Impact pile driving 
produces short, sharp pulses with higher peak levels and much sharper 
rise time to reach those peaks. If impact driving is necessary, 
implementation of soft start and shutdown zones significantly reduces 
any possibility of injury. Given sufficient ``notice'' through use of 
soft start (for impact driving), marine mammals are expected to move 
away from a sound source that is annoying prior to it becoming 
potentially injurious. WETA will also employ the use of 12-inch-thick 
wood cushion block on impact hammers, and a bubble curtain as sound 
attenuation devices. Environmental conditions at Alameda Point mean 
that marine mammal detection ability by trained observers is high, 
enabling a high rate of success in implementation of shutdowns to avoid 
injury.
    WETA's proposed activities are localized and of relatively short 
duration (a maximum of 22 days for pile driving and removal). The 
entire project area is limited to the Central Bay operations and 
maintenance facility area and its immediate surroundings. These 
localized and short-term noise exposures may cause short-term 
behavioral modifications in harbor seals, northern fur seals, northern 
elephant seals, California sea lions, harbor porpoises, bottlenose 
dolphins, and gray whales. Moreover, the proposed mitigation and 
monitoring measures are expected to reduce the likelihood of injury and 
behavior exposures. Additionally, no important feeding and/or 
reproductive areas for marine mammals are known to be within the 
ensonified area during the construction time frame.
    The project also is not expected to have significant adverse 
effects on affected marine mammals' habitat. The project activities 
would not modify existing marine mammal habitat for a significant 
amount of time. The activities may cause some fish to leave the area of 
disturbance, thus temporarily impacting marine mammals' foraging 
opportunities in a limited portion of the foraging range. However, 
because of the short duration of the activities and the relatively 
small area of the habitat that may be affected, the impacts to marine 
mammal habitat are not expected to cause significant or long-term 
negative consequences.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from other 
similar activities, will likely be limited to reactions such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging (if such activity were occurring) (e.g., Thorson and Reyff 
2006; Lerma 2014). Most likely, individuals will simply move away from 
the sound source and be temporarily displaced from the areas of pile 
driving, although even this reaction has been observed primarily only 
in association with impact pile driving. Thus, even repeated Level B 
harassment of some small subset of the overall stock is unlikely to 
result in any significant realized decrease in fitness for the affected 
individuals, and thus would not result in any adverse impact to the 
stock as a whole. For harbor seals that may transit through the 
ensonified area to get to their haul out located approximately 300 m 
from the project area, Level A harassment may occur. However, harbor 
seals are not expected to be in the injurious ensonified area for long 
periods of time; therefore, the potential for those seals to actually 
have PTS is considered unlikely.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No mortality or serious injury is anticipated or 
authorized;
     Level B harassment may consist of, at worst, temporary 
modifications in behavior (e.g. temporary avoidance of habitat or 
changes in behavior);
     The lack of important feeding, pupping, or other areas in 
the action area;
     The high level of ambient noise already in the Alameda 
Point area; and
     The small percentage of the stock that may be affected by 
project activities (<11.479 percent for all species).
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from WETA's construction activities will have a negligible 
impact on the 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

[[Page 29509]]

for specified activities other than military readiness activities. The 
MMPA does not define small numbers and so, in practice, where estimated 
numbers are available, NMFS compares the number of individuals taken to 
the most appropriate estimation of abundance of the relevant species or 
stock in our determination of whether an authorization is limited to 
small numbers of marine mammals. Additionally, other qualitative 
factors may be considered in the analysis, such as the temporal or 
spatial scale of the activities.
    Table 10 details the number of instances that animals could be 
exposed to received noise levels that could cause Level B behavioral 
harassment for the proposed work at the project site relative to the 
total stock abundance. The numbers of animals authorized to be taken 
for all species would be considered small relative to the relevant 
stocks or populations even if each estimated instance of take occurred 
to a new individual--an extremely unlikely scenario. The total percent 
of the population (if each instance was a separate individual) for 
which take is requested is approximately 1.5 percent for harbor seals, 
approximately 11 percent for bottlenose dolphins, and less than 1 
percent for all other species (Table 10). For pinnipeds, especially 
harbor seals occurring in the vicinity of the project area, there will 
almost certainly be some overlap in individuals present day-to-day, and 
the number of individuals taken is expected to be notably lower.
    Based on the analysis contained herein of the proposed activity 
(including the proposed mitigation and monitoring measures) and the 
anticipated take of marine mammals, NMFS preliminarily finds that small 
numbers of marine mammals will be taken relative to the population size 
of the affected species or stocks.

          Table 10--Estimated Numbers and Percentage of Stock That May Be Exposed to Level B Harassment
----------------------------------------------------------------------------------------------------------------
                                                                     Proposed        Stock(s)      Percentage of
                             Species                                authorized       abundance      total stock
                                                                       takes       estimate \1\      (percent)
----------------------------------------------------------------------------------------------------------------
Harbor Seal (Phoca vitulina) California stock...................             467          30,968             1.5
California sea lion (Zalophus californianus) U.S. Stock.........             149         296,750            0.05
Northern elephant seal (Mirounga angustirostris) California                   18         179,000           0.010
 breeding stock.................................................
Northern fur seal (Callorhinus ursinus) California stock........              10          14,050           0.071
Harbor Porpoise (Phocoena phocoena) San Francisco-Russian River               10           9,886           0.101
 Stock..........................................................
Gray whale (Eschrichtius robustus) Eastern North Pacific stock..               2          20,990           0.009
Bottlenose dolphin (Tursiops truncatus) California coastal stock              52             453          11.479
----------------------------------------------------------------------------------------------------------------
\1\ All stock abundance estimates presented here are from the 2015 Pacific Stock Assessment Report.

Unmitigable Adverse Impact Analysis and Determination

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

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the West Coast regional 
Protected Resources Division Office, whenever we propose to authorize 
take for endangered or threatened species.
    No incidental take of ESA-listed marine mammal species is proposed 
for authorization or expected to result from these activities. 
Therefore, NMFS has determined that formal consultation under section 7 
of the ESA is not required for this action.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to WETA for conducting their Central Bay Operations and 
Maintenance Facility Project, 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 for 1 
year from August 1, 2017 through July 31, 2018.
    2. This IHA is valid only for pile driving and removal activities 
associated with the Central Bay Operations and Maintenance Facility 
Project in San Francisco Bay, CA.
    3. General Conditions.
    (a) A copy of this IHA must be in the possession of WETA, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking are summarized in Table 1.
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b). See Table 1 for numbers of take 
authorized.

                    Table 1--Authorized Take Numbers
------------------------------------------------------------------------
                                                  Authorized take
                 Species                 -------------------------------
                                              Level A         Level B
------------------------------------------------------------------------
Harbor seal.............................              18             467
California sea lion.....................               0             149
Northern elephant seal..................               0              18
Northern fur seal.......................               0              10
Harbor porpoise.........................               0              10
Gray whale..............................               0               2

[[Page 29510]]

 
Bottlenose dolphin......................               0              52
------------------------------------------------------------------------

    (d) The taking by injury (Level A harassment), serious injury, or 
death 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, 
unless authorization of take by Level A harassment is listed in 
condition 3(b) of this Authorization.
    (e) WETA shall conduct briefings between construction supervisors 
and crews, marine mammal monitoring team, and WETA staff prior to the 
start of all pile driving and removal activities, and when new 
personnel join the work.
    4. Mitigation Measures.
    The holder of this Authorization is required to implement the 
following mitigation measures.
    (a) For all pile driving and removal, WETA shall implement a 
minimum shutdown zone of 30 m radius around the pile. If a marine 
mammal comes within or approaches the shutdown zone, such operations 
shall cease.
    (b) For in-water heavy machinery work other than pile driving 
(e.g., standard barges, tug boats, barge-mounted excavators, or 
clamshell equipment used to place or remove material), if a marine 
mammal comes within 10 meters, operations shall cease and vessels shall 
reduce speed to the minimum level required to maintain steerage and 
safe working conditions.
    (c) WETA shall establish monitoring locations as described below. 
Please also refer to the Marine Mammal Monitoring Plan (see 
www.nmfs.noaa.gov/pr/permits/incidental/construction.htm).
    i. For all pile driving and removal activities, a minimum of two 
observers shall be deployed, with one positioned to achieve optimal 
monitoring of the shutdown zone and the second positioned to achieve 
optimal monitoring of surrounding waters of Alameda Point and portions 
of San Francisco Bay. If practicable, the second observer should be 
deployed to an elevated position with clear sight lines to the Project 
area.
    ii. These observers shall record all observations of marine 
mammals, regardless of distance from the pile being driven, as well as 
behavior and potential behavioral reactions of the animals. 
Observations near Alameda Point shall be distinguished from those in 
the nearshore waters of San Francisco Bay.
    iii. All observers shall be equipped for communication of marine 
mammal observations amongst themselves and to other relevant personnel 
(e.g., those necessary to effect activity delay or shutdown).
    (d) Monitoring shall take place from thirty minutes prior to 
initiation of pile driving and removal activity through thirty minutes 
post-completion of pile driving and removal activity. In the event of a 
delay or shutdown of activity resulting from marine mammals in the 
shutdown zone, animals shall be allowed to remain in the shutdown zone 
(i.e., must leave of their own volition) and their behavior shall be 
monitored and documented. Monitoring shall occur throughout the time 
required to drive a pile. The shutdown zone must be determined to be 
clear during periods of good visibility (i.e., the entire shutdown zone 
and surrounding waters must be visible to the naked eye).
    (e) If a marine mammal approaches or enters the shutdown zone, all 
pile driving and removal activities at that location shall be halted. 
If pile driving is halted or delayed due to the presence of a marine 
mammal, the activity may not commence or resume until either the animal 
has voluntarily left and been visually confirmed beyond the shutdown 
zone or fifteen minutes have passed without re-detection of small 
cetaceans and pinnipeds and 30 minutes for gray whales.
    (f) Level A and Level B zones may be modified if additional 
hydroacoustic measurements of construction activities have been 
conducted and NMFS has approved of the revised zones.
    (g) Using delay and shut-down procedures, if a species for which 
authorization has not been granted (including but not limited to 
Guadalupe fur seals and humpback whales) or if a species for which 
authorization has been granted but the authorized takes are met, 
approaches or is observed within the Level B harassment zone, 
activities will shut down immediately and not restart until the animals 
have been confirmed to have left the area.
    (h) Monitoring shall be conducted by qualified observers, as 
described in the Monitoring Plan. Trained observers shall be placed 
from the best vantage point(s) practicable to monitor for marine 
mammals and implement shutdown or delay procedures when applicable 
through communication with the equipment operator. Observer training 
must be provided prior to project start and in accordance with the 
monitoring plan, and shall include instruction on species 
identification (sufficient to distinguish the species listed in 3(b)), 
description and categorization of observed behaviors and interpretation 
of behaviors that may be construed as being reactions to the specified 
activity, proper completion of data forms, and other basic components 
of biological monitoring, including tracking of observed animals or 
groups of animals such that repeat sound exposures may be attributed to 
individuals (to the extent possible).
    (i) WETA shall use soft start techniques recommended by NMFS for 
impact pile driving. Soft start requires contractors to provide an 
initial set of strikes at reduced energy, followed by a thirty-second 
waiting period, then two subsequent reduced energy strike sets. Soft 
start shall be implemented at the start of each day's impact pile 
driving and at any time following cessation of impact pile driving for 
a period of thirty minutes or longer.
    (j) Sound attenuation devices--Approved sound attenuation devices 
(e.g. bubble curtain, pile cushion) shall be used during impact pile 
driving operations. WETA shall implement the necessary contractual 
requirements to ensure that such devices are capable of achieving 
optimal performance, and that deployment of the device is implemented 
properly such that no reduction in performance may be attributable to 
faulty deployment.
    (k) Pile driving shall only be conducted during daylight hours.
    5. Monitoring.
    The holder of this Authorization is required to conduct marine 
mammal monitoring during pile driving and removal activities. Marine 
mammal monitoring and reporting shall be conducted in accordance with 
the Monitoring Plan.
    (a) WETA shall collect sighting data and behavioral responses to 
pile driving and removal for marine mammal species

[[Page 29511]]

observed in the region of activity during the period of activity. All 
observers shall be trained in marine mammal identification and 
behaviors, and shall have no other construction-related tasks while 
conducting monitoring.
    (b) For all marine mammal monitoring, the information shall be 
recorded as described in the Monitoring Plan.
    6. Reporting.
    The holder of this Authorization is required to:
    (a) Submit a draft report on all monitoring conducted under the IHA 
within ninety days of the completion of marine mammal monitoring, or 
sixty days prior to the issuance of any subsequent IHA for projects at 
the Project area, whichever comes first. A final report shall be 
prepared and submitted within thirty days following resolution of 
comments on the draft report from NMFS. This report must contain the 
informational elements described in the Monitoring Plan, at minimum 
(see www.nmfs.noaa.gov/pr/permits/incidental/construction.htm), and 
shall also include:
    i. Detailed information about any implementation of shutdowns, 
including the distance of animals to the pile and description of 
specific actions that ensued and resulting behavior of the animal, if 
any.
    ii. Description of attempts to distinguish between the number of 
individual animals taken and the number of incidents of take, such as 
ability to track groups or individuals.
    iii. An estimated total take estimate extrapolated from the number 
of marine mammals observed during the course of construction 
activities, if necessary.
    (b) Reporting injured or dead marine mammals:
    i. In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this IHA, 
such as a serious injury or mortality, WETA shall immediately cease the 
specified activities and report the incident to the Office of Protected 
Resources, NMFS, and the West Coast Regional Stranding Coordinator, 
NMFS. The report must include the following information:
    A. Time and date of the incident;
    B. Description of the incident;
    C. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    D. Description of all marine mammal observations in the 24 hours 
preceding the incident;
    E. Species identification or description of the animal(s) involved;
    F. Fate of the animal(s); and
    G. Photographs or video footage of the animal(s).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with WETA to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. WETA may not resume 
their activities until notified by NMFS.
    ii. In the event that WETA discovers an injured or dead marine 
mammal, and the lead observer determines that the cause of the injury 
or death is unknown and the death is relatively recent (e.g., in less 
than a moderate state of decomposition), WETA shall immediately report 
the incident to the Office of Protected Resources, NMFS, and the West 
Coast Regional Stranding Coordinator, NMFS.
    The report must include the same information identified in 6(b)(i) 
of this IHA. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS will work with WETA to determine 
whether additional mitigation measures or modifications to the 
activities are appropriate.
    iii. In the event that WETA discovers an injured or dead marine 
mammal, and the lead observer determines that the injury or death is 
not associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, scavenger damage), WETA shall report the incident to the 
Office of Protected Resources, NMFS, and the West Coast Regional 
Stranding Coordinator, NMFS, within 24 hours of the discovery. WETA 
shall provide photographs or video footage or other documentation of 
the stranded animal sighting to NMFS.
    7. This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein, or if 
NMFS determines the authorized taking is having more than a negligible 
impact on the species or stock of affected marine mammals.

Request for Public Comments

    We request comment on our analyses, the draft authorization, and 
any other aspect of this Notice of Proposed IHAs for WETA's Central Bay 
construction activities. Please include with your comments any 
supporting data or literature citations to help inform our final 
decision on WETA's request for MMPA authorization.

    Dated: June 23, 2017.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2017-13580 Filed 6-28-17; 8:45 am]
BILLING CODE 3510-22-P