Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to the Chevron Richmond Refinery Long Wharf Maintenance and Efficiency Project in San Francisco Bay, California, 15025-15044 [2017-05843]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 82, Number 56 (Friday, March 24, 2017)]
[Notices]
[Pages 15025-15044]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-05843]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF246


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to the Chevron Richmond Refinery Long 
Wharf Maintenance and Efficiency Project in San Francisco Bay, 
California

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

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

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SUMMARY: NMFS has received an application from Chevron for an 
Incidental Harassment Authorization (IHA) to take marine mammals, by 
harassment, incidental to pile driving and removal associated with the 
Long Wharf Maintenance and Efficiency Project (WMEP). Pursuant to the 
Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its 
proposal to issue an IHA to Chevron to incidentally take marine mammals 
during the specified activity.

DATES: Comments and information must be received no later than April 
24, 2017.

ADDRESSES: Comments on the applications 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.pauline@noaa.gov.
    Instructions: Comments sent by any other method, to any other 
address or individual, or received after the end of the comment period, 
may not be considered by NMFS. 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 for public 
viewing on the Internet at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm 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: Rob Pauline, 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 to allow, upon request by U.S. 
citizens who engage in a specified activity (other than commercial 
fishing) within a specified area, the incidental, but not intentional, 
taking of small numbers of marine mammals, providing that certain 
findings are made and the necessary prescriptions are established.
    The incidental taking of small numbers of marine mammals may be

[[Page 15026]]

allowed only if NMFS (through authority delegated by the Secretary) 
finds that the total taking by the specified activity during the 
specified time period will (i) have a negligible impact on the species 
or stock(s) and (ii) not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant). Further, the permissible methods of taking, as well as the 
other means of effecting the least practicable adverse impact on the 
species or stock and its habitat (i.e., mitigation) must be prescribed. 
Last, requirements pertaining to the monitoring and reporting of such 
taking must be set forth.
    Where there is the potential for serious injury or death, the 
allowance of incidental taking requires promulgation of regulations 
under section 101(a)(5)(A). Subsequently, a Letter (or Letters) of 
Authorization (LOA) may be issued as governed by the prescriptions 
established in such regulations, provided that the level of taking will 
be consistent with the findings made for the total taking allowable 
under the specific regulations. Under section 101(a)(5)(D), NMFS may 
authorize incidental taking by harassment only (i.e., no serious injury 
or mortality), for periods of not more than one year, pursuant to 
requirements and conditions contained within an IHA. The promulgation 
of regulations or issuance of IHAs (with their associated prescripted 
mitigation, monitoring, and reporting) requires notice and opportunity 
for public comment.
    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.''
    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).

Summary of Request

    On July 21, 2014, NMFS received a request from Chevron for 
authorization to take marine mammals incidental to pile driving and 
pile removal associated with the WMEP in San Francisco Bay, California. 
The project was delayed due to funding constraints. Chevron submitted a 
revised version of the request on November 16, 2016, which was deemed 
adequate and complete on January 12, 2017. Chevron proposes to 
undertake the WMEP in order to comply with current Marine Oil Terminal 
Engineering and Maintenance Standards (MOTEMS) requirements and to 
improve safety and efficiency at the Long Wharf. Construction would 
start in 2018, and be complete by the fourth quarter of 2022. 
Therefore, Chevron expects to request additional IHAs in association 
with this multi-year project. The effective dates for this first 
proposed IHA would be from January 1, 2018 through December 31, 2018. 
The use of both vibratory and impact pile driving during pile removal 
and installation during the four-year construction period is expected 
to produce underwater sound at levels that have the potential to result 
in Level B (behavioral) harassment of marine mammals. However, only 
impact driving will occur during 2018 and would be covered under the 
proposed IHA. Species expected to occur in the area and for which 
authorization is requested include California sea lion (Zalophus 
californianus) and Pacific harbor seal (Phoca vitulina).

Description of the Specified Activity

Overview

    The Chevron's Richmond Refinery Long Wharf (Long Wharf) is the 
largest marine oil terminal in California. Its operations are regulated 
primarily by the California State Lands Commission (CSLC) through a 
State Lands lease, Article 5 of CSLC regulations, and MOTEMS 
(California Building Code (CBC) Chapter 31F). The Long Wharf has 
existed in its current location since the early 1900s (Figure 1-1 in 
Application). The Berth 2 fender system (timber pile and whaler) was 
designed and installed in 1940. Marine loading arms, gangways, and 
fender systems at Berths 1, 3 and 4 were installed in 1972. The Berth 4 
fender panels were replaced in 2011 and the Berth 1 fender panels were 
replaced in 2012. The existing configuration of these systems have 
limitations to accepting more modern, fuel efficient vessels with 
shorter parallel mid-body hulls and in some cases do not meet current 
MOTEMS requirements.
    The purpose of the proposed WMEP is to comply with current MOTEMS 
requirements and to improve safety and efficiency at the Long Wharf. To 
meet MOTEMS requirements, the fendering system at Berth 2 is being 
updated and the Berth 4 loading platform will be seismically 
retrofitted to stiffen the structure and reduce movement of the Long 
Wharf in the event of a level 1 or 2 earthquake. Safety will be 
improved by replacing gangways and fire monitors. Efficiency at the 
Long Wharf will be improved by updating the fender system configuration 
at Berth 4 to accommodate newer, more fuel efficient vessels and thus 
reduce idling time for vessels waiting to berth. Further, efficiency 
will be improved by updating the fender system at Berth 1 to 
accommodate barges, enabling balanced utilization across Berths 1, 2, 
and 3.

Dates and Duration

    Project construction would start in 2018, and be completed by the 
fourth quarter of 2022. Pile driving activities would be timed to occur 
within the standard NMFS work windows for listed fish species (June 1 
through November 30) in those four years. The effective date for the 
first proposed IHA would be from January 1, 2018 through December 31, 
2018. Over the course of the multi-year project 249 piles of various 
sizes will be installed via impact and vibratory driving; 161 piles 
will be removed via vibratory removal; and 209 driving days are 
planned. During the first year of construction covered under this 
proposed IHA, eight 24-inch concrete piles would be installed by impact 
driving over 4 workdays at Berth 2.

Specified Geographic Region

    The Long Wharf is located in San Francisco Bay (the Bay) just south 
of the eastern terminus of the Richmond-San Rafael Bridge (RSRB) in 
Contra Costa County. The wharf is located in the northern portion of 
the Central Bay, which is generally defined as the area between the 
RSRB, Golden Gate Bridge, and San Francisco-Oakland Bay Bridge. The 
South Bay is located south of the San Francisco-Oakland Bay Bridge. San 
Pablo Bay extends north of the RSRB.

Detailed Description of Specified Activities

    The complete multi-year project would involve modifications at four 
berths (Berths 1, 2, 3, and 4) as shown in Figure 1-1 in the 
Application. Proposed modifications to the Long Wharf include replacing 
gangways and cranes, adding new mooring hooks and standoff fenders, 
adding new dolphins and catwalks, and modifying the fire water system 
at Berths 1, 2, 3 and/or 4, as well as the seismic retrofit to the 
Berth 4 loading platform. The type and numbers of piles to be 
installed, as well

[[Page 15027]]

as those that will be removed, are summarized in Table 1-1 in the 
Application and an overview of the modifications at Berths 1 to 4 are 
shown in Figure 1-2 in the Application.
    The combined modifications to Berths 1-4 would require the 
installation of 141 new concrete piles to support new and replacement 
equipment and their associated structures. The Berth 4 loading platform 
would add eight, 60-inch diameter steel piles as part of the seismic 
retrofit.
    The project would also add four clusters of 13 composite piles each 
(52 total) as markers and protection of the new batter (driven at an 
angle) piles on the east side of the Berth 4 retrofit. The project 
would remove 106 existing timber piles, two existing 18[hyphen]inch and 
two existing 24[hyphen]inch concrete piles. A total of 12 24-inch 
temporary steel piles would also be installed and removed during the 
seismic retrofit of Berth 4. The modifications at each berth are 
summarized below.
    Modifications at Berth 1 include the following:
     Replace gangway to accommodate barges and add a new raised 
fire monitor.
     Construct a new 24' x 20' mooring dolphin and hook to 
accommodate barges.
     Construct a new 24' x 25' breasting dolphin and 13' x 26' 
breasting point with standoff fenders to accommodate barges.The new 
breasting dolphin will require removal of an existing catwalk and two 
piles and moving a catwalk to a slightly different location to maintain 
access to currently existing dolphins. A new catwalk will be installed 
to provide access to the new breasting dolphin.
     A portion of the existing gangway will be removed. The 
remaining portion is used for other existing services located on its 
structure.
    Much of this work will be above the water or on the deck of the 
terminal. The mooring dolphin and hook, breasting dolphin, and new 
gangway will require installation of 42 new 24[hyphen]inch square 
concrete piles using impact driving methods.
    Modifications at Berth 2 include the following:
     Install new gangway to replace portable gangway and add a 
new elevated fire monitor.
     Replace one bollard with a new hook.
     Install four new standoff fenders (to replace timber 
fender pile system).
     Replace existing auxiliary and hose cranes and vapor 
recovery crane to accommodate the new standoff fenders.
     Remove the existing timber fender pile system along the 
length of the Berth (~650 ft.)
     Three (3) existing brace piles (22-inch square concrete 
jacketed timber piles) would be removed by cutting below the mud line 
if possible.
    These modifications will require the installation of 51 new 24-inch 
square concrete piles, using impact driving methods, to support the 
gangway, standoff fenders, hose crane, and auxiliary crane. To keep 
Berth 2 operational during construction, four temporary fenders will be 
installed, supported by 36 temporary 14-inch H-piles driven using 
vibratory methods. It is expected that the H-piles would largely sink 
under their own weight and would require very little driving. The H-
piles and temporary fenders will be removed once the permanent standoff 
fenders are complete. The auxiliary and hose cranes are being replaced 
with cranes with longer reach to accommodate the additional distance of 
the new standoff fenders. The new vapor recovery crane would be mounted 
on an existing pedestal and not require in[hyphen]water work.
    Modifications at Berth 3 include the following:
     Install new fixed gangway to replace portable gangway and 
add a new raised fire monitor. The gangway would be supported by four, 
24-inch square concrete piles. This would be the only in-water work for 
modifications at Berth 3.
    Modifications at Berth 4 include the following:
     Install two new 36' x 20' dolphins with standoff fenders 
(two per dolphin) and two catwalks.
     Seismically retrofit the Berth 4 loading platform 
including bolstering and relocation of piping and electrical 
facilities.
    The new fenders would add 44 new 24-inch square concrete piles.
    The seismic retrofit would structurally stiffen the Berth 4 Loading 
Platform under seismic loads. This will require cutting holes in the 
concrete decking and driving eight, 60-inch diameter hollow steel 
batter piles, using impact pile driving. To accommodate the new 
retrofit, an existing sump will be replaced with a new sump and two, 
24-inch square concrete piles will be removed or cut to the 
``mudline.'' The engineering team has determined that to drive the 60-
inch batter piles, twelve temporary steel piles, 24 inches in diameter, 
will be needed to support templates for the angled piles during 
driving. Two templates are required, each 24 feet by 4 feet and 
supported by up to six 24-inch steel pipe piles. The templates will be 
above water. The project would also add 4 clusters of 13 composite 
piles each (52 total composite piles) as markers and protection of the 
new batter piles on the east side of the retrofit. See Table 1 for pile 
summary information.

[[Page 15028]]

[GRAPHIC] [TIFF OMITTED] TN24MR17.000

    Note that the proposed IHA covers actions occurring during 2018 
only. These actions include only the installation of eight 24-inch 
concrete piles by impact hammer driving over four workdays. These piles 
would replace existing auxiliary and hose cranes and vapor recovery 
crane at Berth 2. Impact installation would occur utilizing a DelMag 
D62 22 or similar diesel hammer, producing approximately 165,000 ft lbs 
maximum energy (may not need full energy) over a duration of 
approximately 20 minutes per pile.
    Proposed mitigation, monitoring, and reporting measures are 
described in in detail later in the document (Mitigation and Monitoring 
and Reporting sections).

Description of Marine Mammals in the Area of the Specified Activity

    Although 35 species of marine mammals can be found off the coast of 
California, few species venture into San Francisco Bay, and only 
Pacific harbor seals (Phoca vitulina), California sea lions (Zalophus 
californianus), and harbor porpoises (Phocoena phocoena) make the Bay a 
permanent home. Small numbers of gray whales (Eschrichtius robustus) 
are regularly sighted in the Bay during their yearly migration, though 
most sightings tend to occur in the Central Bay near the Golden Gate 
Bridge. Two other species that may occasionally occur within San 
Francisco Bay include the Steller sea lion (Eumetopias jubatus) and 
bottlenose dolphin (Tursiops truncatus).

Pacific Harbor Seal

    The Pacific harbor seal is one of five subspecies of Phoca 
vitulina, or the common harbor seal. They are a true seal, with a 
rounded head and visible ear canal, distinct from the eared seals, or 
sea lions, which have a pointed head and an external ear. Although 
generally solitary in the water, harbor seals come ashore at ``haul-
outs''--shoreline areas where pinnipeds congregate to rest, socialize, 
breed, and molt--that are used for resting, thermoregulation, birthing, 
and nursing pups. 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 (Green et al., 2006). The 
nearest haul-out site to the project site is Castro Rocks, 
approximately 650 meters north

[[Page 15029]]

of the northernmost point on the Long Wharf.
    The haul-out sites at Mowry Slough (~55 km distant from project 
site), in the South Bay, Corte Madera Marsh (~8 km distant) and Castro 
Rocks (~650 m distant), in the northern portion of the Central Bay, and 
Yerba Buena Island (~12 km distant) in the Central Bay, support the 
largest concentrations of harbor seals within the San Francisco Bay. 
The California Department of Transportation (Caltrans) conducted marine 
mammal surveys before and during seismic retrofit work on the RSRB in 
northern San Francisco Bay. The RSRB is located north of the project 
site, The surveys included extensive monitoring of marine mammals at 
points throughout the Bay. Although the study focused on harbor seals 
hauled out at Castro Rocks and Red Rock Island near the RSRB, all other 
observed marine mammals were recorded. Monitoring took place from May 
1998 to February 2002 (Green et al., 2002.) and determined that at 
least 500 harbor seals populate San Francisco Bay. This estimate agrees 
with previous seal counts in San Francisco Bay, which ranged from 524 
to 641 seals from 1987 to 1999 (Goals Project 2000).
    Although births of harbor seals have not been observed at Corte 
Madera Marsh and Yerba Buena Island, a few pups have been seen at these 
sites. The main pupping areas in the San Francisco Bay are at Mowry 
Slough and Castro Rocks (Caltrans 2012). Seals haul out year-round on 
Castro Rocks during medium to low tides; few low tide sites are 
available within San Francisco Bay. The seals at Castro Rocks are 
habituated, to a degree, to some sources of human disturbance such as 
large tanker traffic and the noise from vehicle traffic on the bridge, 
but often flush into the water when small boats maneuver close by or 
when people work on the bridge (Kopec and Harvey 1995). Long-term 
monitoring studies have been conducted at the largest harbor seal 
colonies in Point Reyes National Seashore (~45 km west of the project 
site on Pacific coast) and Golden Gate National Recreation Area (~15 km 
southwest of the project site) since 1976. Castro Rocks and other haul-
outs 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 at Castro Rocks 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 2013).

California Sea Lion

    The California sea lion (Zalophus californianus) belongs to the 
family Otariidae or ``eared seals,'' referring to the external ear 
flaps not shared by other pinniped families. While California sea lions 
forage and conduct many activities within the water, they also use 
haul-outs. California sea lions breed in Southern California and along 
the Channel Islands during the spring.
    In the Bay, sea lions haul out primarily on floating docks at Pier 
39 in the Fisherman's Wharf area of the San Francisco Marina, 
approximately 12.5 km southwest of the project site. The California sea 
lions usually arrive at 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 the Bay. They are seen swimming off mainly the San Francisco 
and Marin County shorelines within the Bay but may occasionally enter 
the project area to forage. Over the monitoring period for the RSRB, 
monitors sighted California sea lions on 90 occasions in the northern 
portion of the Central Bay and at least 57 times in the Central Bay. No 
pupping activity has been observed at this site or at other locations 
within the San Francisco Bay (Caltrans 2012).
    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. Because California sea lions forage over a wide 
range in San Francisco Bay, it is possible that a limited number of 
individuals would be incidentally harassed during construction.

Harbor Porpoise

    The harbor porpoise (Phocoena phocoena) is a member of the 
Phocoenidae family. They generally occur in groups of two to five 
individuals, and are considered to be shy, relatively nonsocial 
animals.
    In prior years, harbor porpoises were observed primarily outside of 
San Francisco Bay. The few harbor porpoises that entered did not 
venture far into the Bay. No harbor porpoises were observed during 
marine mammal monitoring conducted before and during seismic retrofit 
work on the RSRB. In recent years, there have been increasingly common 
observations of harbor porpoises within San Francisco Bay. According to 
observations by the Golden Gate Cetacean Research team, as part of 
their multi- year assessment, approximately 650 harbor porpoises have 
been observed in the San Francisco Bay, and up to 100 may occur on a 
single day (Golden Gate Cetacean Research 2017). In San Francisco Bay, 
harbor porpoises are concentrated in the vicinity of the Golden Gate 
Bridge (approximately 12 km southwest of the project site) and Angel 
Island (5.5 km southwest), with lesser numbers sighted in the vicinity 
of Alcatraz (11 km south) and west of Treasure Island (10 km southeast) 
(Keener 2011). Because this species may venture into the Bay east of 
Angel Island, there is a slight chance that a small number of 
individuals could occur in the vicinity of the proposed project.

Gray Whale

    Gray whales (Eschrichtius robustus) are large baleen whales. They 
are one of the most frequently seen whales along the California coast, 
easily recognized by their mottled gray color and lack of dorsal fin. 
They feed in northern waters primarily off the Bering, Chukchi, and 
western Beaufort seas during the summer, before heading south to the 
breeding and calving grounds off Mexico over the winter. Between 
December and January, late-stage pregnant females, adult males, and 
immature females and males will migrate southward. The northward 
migration peaks between February and March. During this time, recently 
pregnant females, adult males, immature females, and females with 
calves move north to the feeding grounds (NOAA 2003). A few individuals 
will enter into the San Francisco Bay during their northward migration.
    RSRB project monitors recorded 12 living and 2 dead gray whales, 
all in either the Central Bay or San Pablo Bay, and all but 2sightings 
occurred during the months of April and May (Winning 2008). 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 the Bay regularly in the late 1990s. The 
Oceanic Society data show that all age classes of gray whales are 
entering the 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). It is possible that a small number of gray whales enter the Bay 
in any given year, typically from March to May. However, this is 
outside of the June to November window when pile driving would occur.

[[Page 15030]]

Steller Sea Lion

    Steller sea lions (Eumetopias jubatus) have been reported at 
A[ntilde]o Nuevo Island between Santa Cruz and Half Moon Bay and at the 
Farallon Islands about 48 km off the coast of San Francisco (Fuller 
2012). Two studies of Steller sea lion distribution did not detect 
individuals in San Francisco Bay. The SF Bay Subtidal Habitat Goals 
Report, Appendix 2-1 contains one reference to Steller sea lions in the 
San Francisco Bay, stating that since 1989, several hundred California 
sea lions have congregated in the winter on docks at Pier 39, which are 
on rare occasions joined by a few Steller sea lions (Cohen 2010). Over 
a 2-year period from 2010-2012, 16 Steller sea lions were sighted in 
the Bay from land or from the Golden Gate Bridge (GGCR, 2012) This 
species is an uncommon visitor to San Francisco Bay and is not expected 
to occur in the project area during construction. As a result, this 
species is not considered further.

Bottlenose Dolphin

    The range of the bottlenose dolphin (Tursiops truncatus) has 
expanded northward along the Pacific Coast since the 1982-1983 El 
Ni[ntilde]o (Carretta et al., 2013; Wells and Baldridge 1990). They now 
occur as far north as the San Francisco Bay region and have been 
observed along the coast in Half Moon Bay, San Mateo, Ocean Beach in 
San Francisco, and Rodeo Beach in Marin County. Observations indicate 
that bottlenose dolphin occasionally enter San Francisco Bay, sometimes 
foraging for fish in Fort Point Cove, just east of the Golden Gate 
Bridge (Golden Gate Cetacean Research 2014). While individuals of this 
species occasionally enter San Francisco Bay, observations indicate 
that they remain in proximity to the Golden Gate near the mouth of the 
Bay and would not be within the project area during construction. As a 
result, this species is not considered further.
    Table 2 lists the marine mammal species with the potential for 
occurrence in the vicinity of the project during the project timeframe 
and summarizes key information regarding stock status and abundance. 
None of these species are listed as threatened or endangered under the 
Endangered Species Act. Furthermore, they are not listed as depleted or 
as strategic stocks under the MMPA. Section 3 and 4 of Chevron's 
application contains summaries of marine mammal species' status and 
trends, distribution and habitat preferences, behavior and life 
history, and auditory capabilities. Please also refer to NMFS' Web site 
(www.nmfs.noaa.gov/pr/species/mammals/) for generalized species 
accounts. NMFS' Stock Assessment Reports are also available at https://www.nmfs.noaa.gov/pr/sars, and provide more detailed accounts of these 
stocks' status and abundance.

                                     Table 2--Marine Mammals Potentially Present in the Vicinity of the Project \1\
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                                                     ESA/MMPA
                                                     status;        Stock abundance  (CV/Nmin) \3\               Occurrence in/
           Species                   Stock        strategic  (Y/                                      PBR \4\     near project           Seasonal
                                                      N) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
Pacific harbor seal Phoca      California Stock  -/N              30,968 (-/27,348)................      1,641  Common.........  Year-round.
 vitulina.
California sea lion Zalophus   Eastern U.S.      -/N              296,750 (-/153,337)..............      9,200  Uncommon.......  Year-round.
 californianus.                 Stock.
Harbor porpoise Phocoena       San Francisco-    -/N              9,886 (0.51/6,625)...............         66  Common in the    Year-round.
 phocoena.                      Russian River                                                                    vicinity of
                                Stock.                                                                           the Golden
                                                                                                                 Gate and
                                                                                                                 Richardson's
                                                                                                                 Bay, Rare
                                                                                                                 elsewhere.
Gray whale Eschrichtius        Eastern North     -/N              20,990 (0.05/20,125).............        624  Rare to          December-April.
 robustus.                      Pacific Stock.                                                                   occasional.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Source: Carretta et al. 2016.
\2\ 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.
\3\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For certain stocks of
  pinnipeds, abundance estimates are based upon observations of animals (often pups) ashore multiplied by some correction factor derived from knowledge
  of the species' (or similar species') life history to arrive at a best abundance estimate; therefore, there is no associated CV. In these cases, the
  minimum abundance may represent actual counts of all animals ashore.
\4\ 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).

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 may impact marine mammals and 
their habitat. The Estimated Take section later in this document will 
include an analysis of the number of individuals that are expected to 
be taken by this activity. The Negligible Impact Analyses and 
Determination section will consider the content of this section, the 
Estimated Take by Incidental Harassment section, and the 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.
    Impact pile driving may create underwater noise at levels that 
could injure or behaviorally disturb marine mammals. In order to assess 
the level of impacts of sound on marine mammals it is necessary to have 
a basic understanding of underwater sound characteristics and potential 
effects. A brief overview is provided below.

Description of Sound Sources

    Sound travels in waves, the basic components of which are 
frequency, wavelength, velocity, and amplitude.

[[Page 15031]]

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 and attenuate (decrease) more rapidly in shallower water. 
Amplitude is the height of the sound pressure wave or the `loudness' of 
a sound and is typically measured using the 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 [micro]Pa.
    Root mean square (rms) is the quadratic mean sound pressure over 
the duration of an impulse, and is calculated by squaring all of the 
sound amplitudes, averaging the squares, and then taking the square 
root of the average (Urick 1983). Rms accounts for both positive and 
negative values; squaring the pressures makes all values positive so 
that they may be accounted for in the summation of pressure levels 
(Hastings and Popper, 2005). This measurement is often used in the 
context of discussing behavioral effects, in part because behavioral 
effects, which often result from auditory cues, may be better expressed 
through averaged units than by peak pressures.
    When underwater objects vibrate or activity occurs, sound-pressure 
waves are created. These waves alternately compress and decompress the 
water as the sound wave travels. Underwater sound waves radiate in all 
directions away from the source (similar to ripples on the surface of a 
pond), except in cases where the source is directional. The 
compressions and decompressions associated with sound waves are 
detected as changes in pressure by aquatic life and man-made sound 
receptors such as hydrophones.
    Even in the absence of sound from the specified activity, the 
underwater environment is typically loud due to ambient sound. Ambient 
sound is defined as environmental background sound levels lacking a 
single source or point (Richardson et al., 1995), and the sound level 
of a region is defined by the total acoustical energy being generated 
by known and unknown sources. These sources may include physical (e.g., 
waves, earthquakes, ice, atmospheric sound), biological (e.g., sounds 
produced by marine mammals, fish, and invertebrates), and anthropogenic 
sound (e.g., vessels, dredging, aircraft, construction). A number of 
sources contribute to ambient sound, including the following 
(Richardson et al., 1995):
     Wind and waves: The complex interactions between wind and 
water surface, including processes such as breaking waves and wave-
induced bubble oscillations and cavitation, are a main source of 
naturally occurring ambient noise for frequencies between 200 Hz and 50 
kHz (Mitson 1995). In general, ambient sound levels tend to increase 
with increasing wind speed and wave height. Surf noise becomes 
important near shore, with measurements collected at a distance of 8.5 
km from shore showing an increase of 10 dB in the 100 to 700 Hz band 
during heavy surf conditions.
     Precipitation: Sound from rain and hail impacting the 
water surface can become an important component of total noise at 
frequencies above 500 Hz, and possibly down to 100 Hz during quiet 
times.
     Biological: Marine mammals can contribute significantly to 
ambient noise levels, as can some fish and shrimp. The frequency band 
for biological contributions is from approximately 12 Hz to over 100 
kHz.
     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.
    In-water construction activities associated with the project would 
include impact pile driving. Underwater sounds produced by pile driving 
fall into one of two general sound types: Impulsive and non-impulsive 
(defined in the following). The distinction between these two sound 
types is important because they have differing potential to cause 
physical effects, particularly with regard to hearing (e.g., Ward, 1997 
in Southall et al., 2007). Please see Southall et al., (2007) for an 
in-depth discussion of these concepts. Only impulsive sound is 
described as part of this notice of proposed IHA.
    Impulsive sound sources (e.g., explosions, gunshots, sonic booms, 
impact pile driving) produce signals that are brief (typically 
considered to be less than one second), broadband, atonal transients 
(ANSI, 1986; Harris, 1998; NIOSH, 1998; ISO, 2003; ANSI, 2005) and 
occur either as isolated events or repeated in some succession. 
Impulsive sounds are all characterized by a relatively rapid rise from 
ambient pressure to a maximal pressure value followed by a rapid decay 
period that may include a period of diminishing, oscillating maximal 
and minimal pressures, and generally have an increased capacity to 
induce physical injury as compared with sounds that lack these 
features.
    Impact hammers used as part of the proposed project 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).

[[Page 15032]]

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), and the 
revised generalized hearing ranges are presented in the new Guidance. 
The functional hearing groups and the associated frequencies are 
indicated in Table 3 below.

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

Acoustic Effects, Underwater

    Potential Effects of Pile Driving Sound--The effects of sounds from 
pile driving might result in 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., 2004; Nowacek et al., 2007; Southall et al., 2007). The 
effects of pile driving on marine mammals are dependent on several 
factors, including the size, type, and depth of the animal; the depth, 
intensity, and duration of the pile driving sound; the depth of the 
water column; the substrate of the habitat; the standoff distance 
between the pile and the animal; and the sound propagation properties 
of the environment. Impacts to marine mammals from pile driving 
activities are expected to result primarily from acoustic pathways. As 
such, the degree of effect is intrinsically related to the 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. Shallow environments are typically more structurally 
complex, which leads to rapid sound attenuation. 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 would be 
expected to result from physiological and behavioral responses to both 
the type and strength of the acoustic signature (Viada et al., 2008). 
The type and severity of behavioral impacts are more difficult to 
define due to limited studies addressing the behavioral effects of 
impulsive sounds on marine mammals. Potential effects from impulsive 
sound sources can range in severity from effects such as behavioral 
disturbance or tactile perception to physical discomfort, slight injury 
of the internal organs and the auditory system, or mortality (Yelverton 
et al., 1973).
    Hearing Impairment and Other Physical Effects--Marine mammals 
exposed to high intensity sound repeatedly or for prolonged periods can 
experience hearing threshold shift (TS), which is defined as ``a 
change, usually an increase, in the threshold of audibility at a 
specified frequency or portion of an individual's hearing range above a 
previously established reference level'' (NMFS, 2016). The amount of 
threshold shift is customarily expressed in decibels (ANSI 1995, Yost 
2007). A TS can be permanent (PTS) or temporary (TTS). PTS is a 
permanent, irreversible increase in the threshold of audibility at a 
specified frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2016). TTS is a temporary, 
reversible increase in the threshold of audibility at a specified 
frequency or portion of an individual's hearing range above a 
previously established reference level (NMFS 2016).
    Marine mammals depend on acoustic cues for vital biological 
functions (e.g., orientation, communication, finding prey, avoiding 
predators); thus, TTS may result in reduced fitness in survival and 
reproduction. However, this depends on the frequency and duration of 
TTS, as well as the biological context in which it occurs. TTS of 
limited duration, occurring in a frequency range that does not coincide 
with that used for recognition of important acoustic cues, would have 
little to no effect on an animal's fitness. Repeated sound exposure 
that leads to TTS could cause PTS. PTS constitutes injury, but TTS does 
not (Southall et al., 2007). The following subsections discuss in 
somewhat more detail the possibilities of TTS, PTS, and non-auditory 
physical effects.
    Temporary Threshold Shift--TTS is the mildest form of hearing 
impairment that can occur during exposure to a strong sound (Kryter 
1985). While experiencing TTS, the hearing threshold rises, and a sound 
must be stronger in order to be heard. In terrestrial mammals, TTS can 
last from minutes or hours to days (in cases of strong TTS). For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
in both terrestrial and marine mammals recovers rapidly after exposure 
to the sound ends.
    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

[[Page 15033]]

threshold in dB), duration (i.e., recovery time), and frequency range 
of TTS, and the context in which it is experienced, TTS can have 
effects on marine mammals ranging from discountable to serious. For 
example, a marine mammal may be able to readily compensate for a brief, 
relatively small amount of TTS in a non-critical frequency range that 
occurs during a time where ambient noise is lower and there are not as 
many competing sounds present. Alternatively, a larger amount and 
longer duration of TTS sustained during time when communication is 
critical for successful mother/calf interactions could have more 
serious impacts.
    Currently, TTS data only exist for four species of cetaceans 
(bottlenose dolphin (Tursiops truncatus), beluga whale (Delphinapterus 
leucas), harbor porpoise (Phocoena phocoena), and Yangtze finless 
porpoise (Neophocaena asiaeorientalis)) and three species of pinnipeds 
(northern elephant seal (Mirounga angustirostris), harbor seal (Phoca 
vitulina) and California sea lion (Zalophus californianus)) exposed to 
a limited number of sound sources (i.e., mostly tones and octave-band 
noise) in laboratory settings (e.g., Finneran, 2016; Finneran et al., 
2002; Finneran and Schlundt, 2010, 2013; Nachtigall et al., 2004; 
Kastaket et al., 2005; Lucke et al., 2009; Popov et al., 2011). In 
general, harbor seals and harbor porpoises have a lower TTS onset than 
other measured pinniped or cetacean species (Kastak et al., 2005; 
Kastelein et al., 2011, 2012a, 2012b, 2013a, 2013b, 2014a, 2014b, 
2015a, 2015b, 2015c, 2016). Additionally, the existing marine mammal 
TTS data come from a limited number of individuals within these 
species. There are no data available on noise-induced hearing loss for 
mysticetes. For summaries of data on TTS in marine mammals or for 
further discussion of TTS onset thresholds, please see Southall et al., 
(2007), Finneran and Jenkins (2012), and Finneran (2016).
    Permanent Threshold Shift--When PTS occurs, there is physical 
damage to the sound receptors in the ear. In severe cases, there can be 
total or partial deafness, while in other cases the animal has an 
impaired ability to hear sounds in specific frequency ranges (Kryter 
1985). There is no specific evidence that exposure to pulses of sound 
can cause PTS in any marine mammal. However, given the possibility that 
mammals close to a sound source might incur TTS, there has been further 
speculation about the possibility that some individuals might incur 
PTS. Single or occasional occurrences of mild TTS are not indicative of 
permanent auditory damage, but repeated or (in some cases) single 
exposures to a level well above that causing TTS onset might elicit 
PTS.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals but are assumed to be similar to those in humans and 
other terrestrial mammals. Available data from humans and other 
terrestrial mammals indicate that a 40 dB threshold shift approximates 
PTS onset (see Ward et al., 1958, 1959; Ward 1960; Kryter et al., 1966; 
Miller 1974; Ahroon et al., 1996; Henderson et al., 2008).
    PTS onset acoustic thresholds for marine mammals have not been 
directly measured and must be extrapolated from available TTS onset 
measurements. Thus, based on cetacean measurements from TTS studies 
(see Southall et al., 2007; Finneran, 2015; Finneran, 2016 (found in 
Appendix A of the Guidance)) a threshold shift of 6 dB is considered 
the minimum threshold shift clearly larger than any day-to-day or 
session-to-session variation in a subject's normal hearing ability and 
is typically the minimum amount of threshold shift that can be 
differentiated in most experimental conditions (Finneran et al., 2000; 
Schlundt et al., 2000; Finneran et al., 2002).
    Measured peak underwater source levels from impact pile driving can 
be as high as 214 dB re 1 [micro]Pa (Laughlin 2011). Although no marine 
mammals have been shown to experience TTS or PTS as a result of being 
exposed to pile driving activities, captive bottlenose dolphins and 
beluga whales exhibited changes in behavior when exposed to strong-
pulsed sounds (Finneran et al., 2000, 2002, 2005). The animals 
tolerated high received levels of sound before exhibiting aversive 
behaviors. Experiments on a beluga whale showed that exposure to a 
single watergun impulse at a received level of 207 kilopascal (kPa) (30 
psi) peak-to-peak (p-p), which is equivalent to 228 dB p-p, resulted in 
a 7 and 6 dB TTS in the beluga whale at 0.4 and 30 kHz, respectively. 
Thresholds returned to within 2 dB of the pre-exposure level within 
four minutes of the exposure (Finneran et al., 2002). Although the 
source level of pile driving from one hammer strike is expected to be 
much lower than the single watergun impulse cited here, animals being 
exposed for a prolonged period to repeated hammer strikes could receive 
more sound exposure in terms of sound exposure level (SEL) than from 
the single watergun impulse (estimated at 188 dB re 1 [mu]Pa\2\-s) in 
the aforementioned experiment (Finneran et al., 2002). However, in 
order for marine mammals to experience TTS or PTS, the animals have to 
be close enough to be exposed to high intensity sound levels for a 
prolonged period.
    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 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. Given the modest number of piles that will be driven, 
limited driving time per pile, short duration of the project, 
relatively low sound source levels, and small Level A (injury) 
harassment zones, NMFS is confident that marine mammals would not 
experience auditory or non-acoustic physiological impacts.

Disturbance Reactions

    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

[[Page 15034]]

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. Behavioral state may affect the type of response as well. 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 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 guns or acoustic harassment devices, but 
also including pile driving) have been varied but often consist of 
avoidance behavior or other behavioral changes suggesting discomfort 
(Morton and Symonds 2002; Thorson and Reyff 2006; see also Gordon et 
al., 2004; Wartzok et al., 2003; Nowacek et al., 2007).
    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 
(cetaceans only), 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; 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 the amount of time 
spent hauled out, possibly to avoid in-water disturbance (Thorson and 
Reyff 2006). Since pile driving would likely only occur for a few hours 
a day, over a short period, it is unlikely to result in permanent 
displacement. Any potential impacts from pile driving activities could 
be experienced by individual marine mammals, but would not be likely to 
cause population level impacts, or affect the long-term fitness of the 
species.
    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);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     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).

Stress Responses

    An animal's perception of a threat may be sufficient to trigger 
stress responses consisting of some combination of behavioral 
responses, autonomic nervous system responses, neuroendocrine 
responses, or immune responses (e.g., Seyle 1950; Moberg 2000). In many 
cases, an animal's first and sometimes most economical (in terms of 
energetic costs) response is behavioral avoidance of the potential 
stressor. Autonomic nervous system responses to stress typically 
involve changes in heart rate, blood pressure, and gastrointestinal 
activity. These responses have a relatively short duration and may or 
may not have a significant long-term effect on an animal's fitness.
    Neuroendocrine stress responses often involve the hypothalamus-
pituitary-adrenal system. Virtually all neuroendocrine functions that 
are affected by stress--including immune competence, reproduction, 
metabolism, and behavior--are regulated by pituitary hormones. Stress-
induced changes in the secretion of pituitary hormones have been 
implicated in failed reproduction, altered metabolism, reduced immune 
competence, and behavioral disturbance (e.g., Moberg 1987; Blecha 
2000). Increases in the circulation of glucocorticoids are also equated 
with stress (Romano et al., 2004).
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and ``distress'' is the cost of 
the response. During a stress response, an animal uses glycogen stores 
that can be quickly replenished once the stress is alleviated. In such 
circumstances, the cost of the stress response would not pose serious 
fitness consequences. However, when an animal does not have sufficient 
energy reserves to satisfy the energetic costs of a stress response, 
energy resources must be diverted from other functions. This state of 
distress will last until the animal replenishes its energetic reserves 
sufficient to restore normal function.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses are well-studied through 
controlled experiments and for both laboratory and free-ranging animals 
(e.g., Holberton et al., 1996; Hood et al., 1998; Jessop et al., 2003; 
Krausman et al., 2004; Lankford et al., 2005). Stress responses due to 
exposure to anthropogenic sounds or other stressors and their effects 
on marine mammals have also been reviewed (Fair and Becker 2000; Romano 
et al., 2002b) and, more rarely, studied in wild populations (e.g., 
Romano et al., 2002a). For example, Rolland et al. (2012) found that 
noise reduction from reduced ship traffic in the Bay of Fundy was 
associated with decreased stress in North Atlantic right whales. These 
and other studies lead to a reasonable expectation that some marine 
mammals will experience physiological stress responses upon exposure to 
acoustic stressors and that it is possible that some of these would be 
classified as ``distress.'' In addition, any animal experiencing TTS 
would likely also experience stress responses (NRC 2003).

Auditory Masking

    Natural and artificial sounds can disrupt behavior by masking, or 
interfering with, a marine mammal's ability to hear other sounds. 
Masking occurs when the receipt of a sound is interfered with by 
another coincident

[[Page 15035]]

sound at similar frequencies and at similar or higher levels. Chronic 
exposure to excessive, though not high-intensity, sound could cause 
masking at particular frequencies for marine mammals that utilize sound 
for vital biological functions. Masking can interfere with detection of 
acoustic signals such as communication calls, echolocation sounds, and 
environmental sounds important to marine mammals. Therefore, under 
certain circumstances, marine mammals whose acoustical sensors or 
environment are being severely masked could also be impaired from 
maximizing their performance fitness in survival and reproduction. If 
the coincident (masking) sound were man-made, it could be potentially 
harassing if it disrupted hearing-related behavior. 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. Because sound 
generated from in-water pile driving is mostly concentrated at low 
frequency ranges, it may affect detection of communication calls and 
other potentially important natural sounds such as surf and prey sound. 
It may also affect communication signals when they occur near the sound 
band and thus reduce the communication space of animals (e.g., Clark et 
al., 2009) and cause increased stress levels (e.g., Foote et al., 2004; 
Holt et al., 2009).
    Masking has the potential to impact species at the population or 
community levels as well as at individual levels. Masking affects both 
senders and receivers of the signals and can potentially have long-term 
chronic effects on marine mammal species and populations. Recent 
research suggests that 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, and that most of 
these increases are from distant shipping (Hildebrand 2009). All 
anthropogenic sound sources, such as those from vessel traffic, pile 
driving, and dredging activities, contribute to the elevated ambient 
sound levels, thus intensifying masking.
    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 twenty 
minutes per pile.

Anticipated Effects on Habitat

    The proposed project would result in small net increase in bay fill 
of approximately 0.01 acre of benthic habitat due to the placement of 
piles. The piles would generally be placed within the existing 
footprint of the Long Wharf. This would not have a measurable influence 
on habitat for marine mammals in the Bay. A temporary, small-scale loss 
of foraging habitat may occur for marine mammals if marine mammals 
leave the area during pile driving activities. Acoustic energy created 
during pile replacement work would have the potential to disturb fish 
within the vicinity of the pile replacement work. As a result, the 
affected area could have a temporarily decreased foraging value to 
marine mammals. During pile driving, high noise levels may exclude fish 
from the vicinity of pile driving; Hastings and Popper (2005) 
identified several studies that suggest fish will relocate to avoid 
areas of damaging noise energy. An analysis of potential noise output 
of the proposed project indicates that the distance from underwater 
pile driving at which noise has the potential to cause temporary 
hearing loss in fish ranges from approximately 10 to 158 m (32 ft to 
520 ft) from pile driving activity, depending on the type of pile. 
Therefore, if fish leave the area of disturbance, pinniped foraging 
habitat may have temporarily decreased foraging value when piles are 
driven.
    The duration of fish avoidance of this area after pile driving 
stops is unknown. However, the affected area represents an extremely 
small portion of the total area within foraging range of marine mammals 
that may be present in the project area.
    As such, the main impact 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 most likely impact to marine mammal habitat occurs from pile 
driving effects on likely marine mammal prey (i.e., fish) near the 
project location, and minor impacts to the immediate substrate during 
installation and removal of piles during the dock construction project.
    Effects on Potential Prey--Construction activities would produce 
impulsive 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) 
and are therefore not directly comparable with the proposed project. 
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. In 
general, impacts to marine mammal prey species from the proposed 
project are expected to be minor and temporary due to the relatively 
short timeframe of four days of pile driving activities for a total of 
160 minutes that would occur under the proposed IHA.
    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.
    Effects on Potential Foraging Habitat--San Francisco Bay is 
classified as Essential Fish Habitat (EFH) under the Magnuson-Stevens 
Fisheries Conservation and Management Act, as amended by the 
Sustainable Fisheries Act. The EFH provisions of the Sustainable 
Fisheries Act are designed to protect fisheries habitat from being lost 
due to disturbance and degradation. The act requires implementation of 
measures to conserve and enhance EFH. San Francisco Bay, including the 
area of the project, is classified as EFH for 20 species of 
commercially important fish and sharks that are federally managed under 
three fisheries management plans (FMPs): Coastal Pelagic, Pacific 
Groundfish, and Pacific Coast Salmon (Table 9-1 in the Application). 
The Pacific Coast Salmon FMP includes Chinook salmon.
    In addition to EFH designations, San Francisco Bay is designated as 
a Habitat Area of Particular Concern (HAPC) for various fish species 
within the Pacific Groundfish and Coastal Pelagic FMPs, as this 
estuarine system serves as breeding and rearing grounds important to 
these fish stocks. A number of these

[[Page 15036]]

fish species are prey species for pinnipeds.
    Given the short duration of increased underwater noise levels and 
small project footprint associated with the proposed project, there is 
not likely to be a permanent, adverse effect on EFH. Therefore, the 
project is not likely to have a permanent, adverse effect on marine 
mammal foraging habitat.
    Any behavioral avoidance by fish of the disturbed area would still 
leave significantly large areas of fish and marine mammal foraging 
habitat in San Francisco Bay. While the proposed project would result 
in a small net increase in Bay fill of approximately 0.01 acre of 
benthic foraging habitat, this would not have a measurable influence on 
habitat for marine mammals in the Bay.
    In summary, given the short duration of sound associated with 
individual pile driving events and the relatively small area that would 
be affected, pile driving activities associated with the proposed 
action are not likely to have a permanent, adverse effect on any fish 
habitat, or populations of fish species. Thus, any impacts to marine 
mammal habitat are not expected to cause significant or long-term 
consequences for individual marine mammals or their populations.

Estimated Take

    This section includes an estimate of the number of incidental 
``takes'' proposed for authorization pursuant to this IHA, which will 
inform both NMFS' consideration of whether the number of takes is 
``small'' and the negligible impact determination.
    Harassment is the primary means of take expected to result from 
these activities. 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).
    As described previously in the Effects section, Level B Harassment 
is expected to occur and is proposed to be authorized for select 
species in numbers identified below. Based on the nature of the 
activity and the anticipated effectiveness of the mitigation measures, 
Level A harassment is neither anticipated nor proposed to be 
authorized.
    In order to estimate the potential incidents of take that may occur 
incidental to the specified activity, we must first estimate the extent 
of the sound field that may be produced by the activity and then 
consider the sound field in combination with information about marine 
mammal density or abundance in the project area. We first provide 
information on applicable sound thresholds for determining effects to 
marine mammals before describing the information used in estimating the 
sound fields, the available marine mammal density or abundance 
information, and the method of estimating potential incidences of take
    Sound Thresholds--NMFS uses sound exposure thresholds to determine 
when an activity that produces underwater sound might result in impacts 
to a marine mammal such that a ``take'' by harassment might occur. On 
August 4, 2016, NMFS released its Technical Guidance for Assessing the 
Effects of Anthropogenic Sound on Marine Mammal Hearing (Guidance) (81 
FR 51694) (available at https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm). This new guidance established new thresholds for 
predicting auditory injury, which equates to Level A harassment under 
the MMPA. As will be discussed below, NMFS has revised PTS (and TTS) 
onset acoustic thresholds for impulsive and non-impulsive sound as part 
of its new acoustic guidance. The Guidance does not address Level B 
harassment; therefore, NMFS uses the current acoustic exposure criteria 
to determine exposure to underwater noise sound pressure levels for 
Level B harassment (Table 4).
    During the installation of piles, the project has the potential to 
increase airborne noise levels. Airborne pile-driving RMS noise levels 
above the NMFS airborne noise thresholds are not expected to extend to 
the Castro Rocks haul-out site, which is located 650 m north of Long 
Wharf. In addition, the Castro Rocks haul out is subject to high levels 
of background noise from the Richmond Bridge, ongoing vessel activity 
at the Long Wharf, ferry traffic, and other general boat traffic. Any 
pinnipeds that surface in the area over which the airborne noise 
thresholds may be exceeded would have already been exposed to 
underwater noise levels above the applicable thresholds and thus would 
not result in an additional incidental take. Airborne noise is not 
considered further.
    Source Levels--Pile driving generates underwater noise that can 
potentially result in disturbance to marine mammals in the project 
area. In order to establish distances to PTS and behavioral harassment 
isopleths, the sound source level associated with a specific pile 
driving activity must be measured directly or estimated using proxy 
information. The intensity of pile driving sounds is greatly influenced 
by factors such as the material type and dimension of piles. To 
estimate the noise effects of the 24-inch square concrete piles 
proposed for use in Year 1 of this project, Chevron reviewed sound 
pressure levels (SPLs) from other projects conducted under similar 
circumstances. These projects include the Pier 40 Berth Construction in 
San Francisco, and the Berth 22 and Berth 32 reconstruction projects at 
the Port of Oakland. However, NMFS elected to use data from only the 
Pier 40 project since 24-inch square concrete piles were installed at 
that location. At Berth 22 and Berth 32, 24-inch octagonal concrete 
piles were installed. The differences in pile shape may result in 
varying SPLs. Impact pile driving at Pier 40 resulted in measured RMS 
values ranging from 162-174 dB and peak SPLs from 172 to 186 dB. SEL 
measurements were not recorded. From Pier 40, NMFS selected a RMS value 
of 170 dB, which was the average of the eight piles tested, excluding 2 
piles that utilized ``jetting''. Jetting consists of employing a 
carefully directed and pressurized flow of water to assist in pile 
placement by liquefying soils at the pile tip during pile placement. 
Jetting tends to increase driving efficiency while decreasing sound 
levels and will not be utilized by Chevron during this project. NMFS 
used an identical approach to arrive at an average peak value of 181 
dB.
Based on Pier 40 Results
    Sound Propagation--Transmission loss (TL) is the decrease in 
acoustic intensity as an acoustic pressure wave propagates out from a 
source. TL parameters vary with frequency, temperature, sea conditions, 
current, source and receiver depth, water depth, water chemistry, and 
bottom composition and topography. The general formula for underwater 
TL is:

TL = B * log10 (R1/R2),

Where:

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

[[Page 15037]]

absence of reflective or absorptive conditions including in-water 
structures and sediments. Spherical spreading occurs in a perfectly 
unobstructed (free-field) environment not limited by depth or water 
surface, resulting in a 6 dB reduction in sound level for each doubling 
of distance from the source (20*log(range)). Cylindrical spreading 
occurs in an environment in which sound propagation is bounded by the 
water surface and sea bottom, resulting in a reduction of 3 dB in sound 
level for each doubling of distance from the source (10*log(range)). As 
is common practice in coastal waters, here we assume practical 
spreading loss (4.5 dB reduction in sound level for each doubling of 
distance) here. Practical spreading is a compromise that is often used 
under conditions where water increases with depth as the receiver moves 
away from the shoreline, resulting in an expected propagation 
environment that would lie between spherical and cylindrical spreading 
loss conditions.
    Level A Zone--Chevron's Level A harassment zone was calculated by 
utilizing the methods presented in Appendix D of NMFS' Guidance and the 
accompanying User Spreadsheet. The Guidance provides updated PTS onset 
thresholds using the cumulative SEL (SELcum) metric, which 
incorporates marine mammal auditory weighting functions, to identify 
the received levels, or acoustic thresholds, at which individual marine 
mammals are predicted to experience changes in their hearing 
sensitivity for acute, incidental exposure to all underwater 
anthropogenic sound sources. The Guidance (Appendix D) and its 
companion User Spreadsheet provide alternative methodology for 
incorporating these more complex thresholds and associated weighting 
functions.
    The User Spreadsheet accounts for weighting functions using 
Weighting Factor Adjustments (WFAs), and NMFS used the recommended 
values for impact driving therein (2 kHz). Pile driving durations were 
estimated based on similar project experience. NMFS' new acoustic 
thresholds use dual metrics of SELcum and peak sound level (PK) for 
impulsive sounds (e.g., impact pile driving). The noise levels noted 
above were used in the Spreadsheet for 24-inch square concrete piles. 
It was estimated that two piles would be installed in one 24-hr workday 
with installation for each pile requiring approximately 300 blows. NMFS 
used an RMS of 170 dB and pulse duration of 0.1 seconds. Measured SEL 
values were not available for 24-inch square concrete piles.
    Utilizing the User Spreadsheet, NMFS applied the updated PTS onset 
thresholds for impulsive PK and SELcum in the new acoustic guidance to 
determine distance to the isopleths for PTS onset for impact pile 
driving. In determining the cumulative sound exposure levels, the 
Guidance considers the duration of the activity, the sound exposure 
level produced by the source during a 24-hr period, and the generalized 
hearing range of the receiving species. In the case of the duel metric 
acoustic thresholds for impulsive sound, the larger of the two 
isopleths for calculating PTS onset is used. Results in Table 4 display 
the Level A injury zones for the various hearing groups.

          Table 4--Injury Zones and Shutdown Zones for Hearing Groups Associated With Installation of 24-Inch Concrete Piles via Impact Driving
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         High-frequency
           Hearing group                  Low-frequency           Mid-frequency        cetaceans (harbor       Phocid pinnipeds    Otariid pinnipeds (CA
                                     cetaceans (gray whale)         cetaceans              porpoise)            (harbor seal)            sea lion)
--------------------------------------------------------------------------------------------------------------------------------------------------------
PTS Onset Acoustic Thresholds--      Lpk,flat: 219 dB......  Lpk,flat: 230 dB......  Lpk,flat: 202 dB.....  Lpk,flat: 218 dB.....  Lpk,flat: 232 dB.
 Impulsive * (Received Level).       LE,LF,24h: 183 dB.....  LE,MF,24h: 185 dB.....  LE,HF,24h: 155 dB....  LE,PW,24h: 185 dB....  LE,OW,24h: 203 dB.
PTS Isopleth to threshold (m)......  20.8..................  0.7...................  24.8.................  11.1.................  0.8.
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Dual metric acoustic thresholds for impulsive sounds: Use whichever results in the largest isopleth for calculating PTS onset. If a non-impulsive
  sound has the potential of exceeding the peak sound pressure level thresholds associated with impulsive sounds, these thresholds should also be
  considered.
Note: Peak sound pressure (Lpk) has a reference value of 1 [mu]Pa, and cumulative sound exposure level (LE) has a reference value of 1 [mu]Pa\2\s. In
  this Table, thresholds are abbreviated to reflect American National Standards Institute standards (ANSI 2013). However, peak sound pressure is defined
  by ANSI as incorporating frequency weighting, which is not the intent for this Technical Guidance. Hence, the subscript ``flat'' is being included to
  indicate peak sound pressure should be flat weighted or unweighted within the generalized hearing range. The subscript associated with cumulative
  sound exposure level thresholds indicates the designated marine mammal auditory weighting function (LF, MF, and HF cetaceans, and PW and OW pinnipeds)
  and that the recommended accumulation period is 24 hours. The cumulative sound exposure level thresholds could be exceeded in a multitude of ways
  (i.e., varying exposure levels and durations, duty cycle). When possible, it is valuable for action proponents to indicate the conditions under which
  these acoustic thresholds will be exceeded.

    The zone of influence (ZOI) refers to the area(s) in which SPLs 
equal or exceed NMFS' current Level B harassment thresholds (160 dB for 
impulse sound). Calculated radial distances to the 160 dB threshold 
assume a field free of obstruction. Assuming a source level of 170 dB 
RMS, installation of the 24-inch concrete piles is expected to produce 
underwater sound exceeding the Level B 160 dB RMS threshold over a 
distance of 46 meters (150 feet) (Table 5).

        Table 5--Isopleth for Level B Harassment Associated With Impact Driving of 24-Inch Concrete Piles
----------------------------------------------------------------------------------------------------------------
                                                                                                     Isopleth
                Criterion                         Definition                   Threshold          (distance from
                                                                                                      source)
----------------------------------------------------------------------------------------------------------------
Level B harassment......................  Behavioral disruption.....  160 dB RMS (impulse                   46 m
                                                                       sources).
----------------------------------------------------------------------------------------------------------------


[[Page 15038]]

    Density/Abundance--Data specifying a marine mammal's density or 
abundance in a given area can often be used to generate exposure 
estimates. However, no systematic line transect surveys of marine 
mammals have been performed in the San Francisco Bay near the project 
site. Density information for marine mammal species has been generated 
by Caltrans based on 15 years (2000-2015) of observations as part of 
the San Francisco-Oakland Bay Bridge replacement project (Caltrans 
2016). The data revealed densities of 0.00004 animals/km\2\ for gray 
whale, 0.021 animals/km\2\ for harbor porpoise, 0.09 animals/km\2\ for 
California sea lion, and 0.17 animals/km\2\ for harbor seal. 
Utilization of these data to develop exposure estimates results in very 
small exposure values. Despite the near zero estimate provided through 
use of the Caltrans density data, local observational data leads us to 
believe that this estimate may not be accurate in illustrating the 
potential for take at this particular site, so we have to use other 
information. Instead, NMFS relied on local observational data as 
described below.
    Take Estimate--The estimated number of marine mammals that may be 
exposed to noise at levels expected to result in take as defined in the 
MMPA is determined by comparing the calculated areas over which the 
Level B harassment threshold may be exceeded, as described above, with 
the expected distribution of marine mammal species within the vicinity 
of the proposed project. NMFS calculated take qualitatively utilizing 
observational data taken during marine mammal monitoring associated 
with the RSRB retrofit project, the San Francisco-Oakland Bay Bridge 
replacement project, and other marine mammal observations for San 
Francisco Bay. As described previously in the Effects section, Level B 
Harassment is expected to occur and is proposed to be authorized in the 
numbers identified below.

Pacific Harbor Seal

    Castro Rocks is the largest harbor seal haul out site in the 
northern part of San Francisco Bay and is the second largest pupping 
site in the Bay (Green et al., 2002). The pupping season is from March 
to June in San Francisco Bay. During the molting season (typically 
June-July and coinciding with the period when piles will be driven) as 
many as 129 harbor seals have been observed using Castro Rocks as a 
haul out. Harbor seals are more likely to be hauled out in the late 
afternoon and evening, and are more likely to be in the water during 
the morning and early afternoon (Green et al., 2002). However, during 
the molting season, harbor seals spend more time hauled out and tend to 
enter the water later in the evening. During molting, harbor seals can 
stay onshore resting for an average of 12 hours per day during the molt 
compared to around 7 hours per day outside of the pupping/molting 
seasons (NPS 2014).
    Tidal stage is a major controlling factor of haul out usage at 
Castro Rocks with more seals present during low tides than high tide 
periods (Green et al., 2002). Additionally, the number of seals hauled 
out at Castro Rocks also varies with the time of day, with 
proportionally more animals hauled out during the nighttime hours 
(Green et al. 2002). Therefore, the number of harbor seals in the water 
around Castro Rocks will vary throughout the work period. The take 
estimates are based on the highest number of harbor seals observed at 
Castro Rocks during 2007 to 2012 annual surveys (approximately 129 
seals). Without site-specific data, it is impossible to determine how 
many hauled out seals enter the water and, of those, how many enter 
into the Level B harassment area. Given the relatively small size of 
the Level B harassment area compared to the large expanse of Bay water 
that is available to the seals, NMFS will assume that no more than 6 
seals per day would enter into the Level B harassment area during the 
40 minutes of pile driving per day scheduled to occur over 4 days. 
Therefore, NMFS proposes that up to 6 seals per day may be exposed to 
Level B harassment over 4 days of impact driving, resulting in a total 
of 24 takes.

California Sea Lion

    Relatively few California sea lions are expected to be present in 
the project area during periods of pile driving, as there are no haul-
outs utilized by this species in the vicinity. However, monitoring for 
the RSRB did observe small numbers of this species in the north and 
central portions of the Bay during working hours. During monitoring 
that occurred over a period of May 1998 to February 2002, California 
sea lions were sighted at least 90 times in the northern portion of the 
Central Bay and at least 57 times near the San Francisco-Oakland Bay 
Bridge in the Central Bay. During monitoring for the San Francisco-
Oakland Bay Bridge Project in the Central Bay, California sea lions 
were observed on 69 occasions in the vicinity of the bridge over a 14-
year period from 2000-2014 (Caltrans 2015b). The limited data regarding 
these observations do not allow a quantitative assessment of potential 
take. Given the limited driving time, low number of sea lions that are 
likely to be found in the northern part of the Bay, and small size of 
the level B zone, NMFS is proposing a total of 2 California sea lion 
takes.

Harbor Porpoise

    A small but growing population of harbor porpoises utilizes San 
Francisco Bay. Harbor porpoises are typically spotted in the vicinity 
of Angel Island and the Golden Gate Bridge (6 and 12 km southwest 
respectively) (Keener 2011), but may utilize other areas in the Central 
Bay in low numbers, including the project area. The density and 
frequency of this usage throughout the Bay is unknown. For this 
proposed IHA, NMFS is not authorizing take of any harbor porpoise since 
the proposed exclusion zone will be conservatively set at 50 m, which 
is larger than the Level B zone isopleth of 46 m, and take can be 
avoided.

Gray Whale

    The only whale species that enters San Francisco bay with any 
regularity is the gray whale. Gray whales occasionally enter the Bay 
during their northward migration period, and are most often sighted in 
the Bay between February and May. Most venture only about 2 to 3 km 
past the Golden Gate Bridge, but gray whales have occasionally been 
sighted as far north as San Pablo Bay. Impact pile driving is not 
expected to occur during this time, however, and gray whales are not 
likely to be present at other times of year. Furthermore, the proposed 
exclusion zone of 50 m for this species is larger than the Level B zone 
isopleth of 46 m. As such, NMFS is not proposing to authorize any gray 
whale take.
    Table 6 shows estimated Level B take for authorized species.

[[Page 15039]]



                                                      Table 6--Summary of Estimated Take by Species
                                                                  [Level B Harassment]
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                                                                     Species
                    Pile type                              Pile driver type           Number of piles     Number of    ---------------------------------
                                                                                                         driving days     Harbor seal      CA sea lion
--------------------------------------------------------------------------------------------------------------------------------------------------------
24-inch square concrete.........................  Impact............................               8                4               24                2
--------------------------------------------------------------------------------------------------------------------------------------------------------

Mitigation

    Under section 101(a)(5)(D) of the MMPA, NMFS shall prescribe the 
``permissible methods of taking by harassment pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for subsistence uses.''
    To ensure that the ``least practicable impact'' will be achieved, 
NMFS evaluates mitigation measures in consideration of the following 
factors in relation to one another: 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, 
their habitat, and their availability for subsistence uses (latter 
where relevant); the proven or likely efficacy of the measures; and the 
practicability of the measures for applicant implementation.

Mitigation for Mammals and Their Habitat

    The following measures would apply to Chevron's mitigation through 
the exclusion zone and zone of influence ZOI:
    Time Restriction--For all in-water pile driving activities, Chevron 
shall operate only during daylight hours when visual monitoring of 
marine mammals can be conducted.
    Seasonal Restriction--To minimize impacts to listed fish species, 
pile-driving activities would occur between June 1 and November 30.
    Exclusion Zone--For all pile driving activities, Chevron will 
establish an exclusion zone intended to contain the area in which Level 
A harassment thresholds are exceeded. The purpose of the exclusion zone 
is to define an area within which shutdown of construction activity 
would occur upon sighting of a marine mammal within that area (or in 
anticipation of an animal entering the defined area), thus preventing 
potential injury of marine mammals. The calculated distance to Level A 
harassment isopleths threshold during impact pile driving, assuming a 
maximum of 2 piles per day is 25 m for harbor porpoise; 11.1 m for 
harbor seal; 0.8 m for California sea lion, and; 20.8 m for gray 
whales.
    NMFS proposes to require a 15 m exclusion zone for harbor seals and 
California sea lions. In order to prevent any take of the cetacean 
species, a 50 m exclusion zone is proposed for harbor porpoises and 
gray whales. A shutdown will occur prior to a marine mammal entering 
the shutdown zones. Activity will cease until the observer is confident 
that the animal is clear of the shutdown zone. The animal will be 
considered clear if:
     It has been observed leaving the shutdown zone; or
     It has not been seen in the shutdown zone for 30 minutes 
for cetaceans and 15 minutes for pinnipeds.
    10-meter Shutdown Zone--During the in-water operation of heavy 
machinery (e.g., barge movements), a 10-m shutdown zone for all marine 
mammals will be implemented. If a marine mammal comes within 10 m, 
operations shall cease and vessels shall reduce speed to the minimum 
level required to maintain steerage and safe working conditions.
    Level B Harassment Zone (Zone of Influence)--The ZOI refers to the 
area(s) in which SPLs equal or exceed NMFS' current Level B harassment 
thresholds (160 dB rms for pulse sources). ZOIs provide utility for 
monitoring that is conducted for mitigation purposes (i.e., exclusion 
zone monitoring) by establishing monitoring protocols for areas 
adjacent to the exclusion zone. Monitoring of the ZOI enables observers 
to be aware of, and communicate about, the presence of marine mammals 
within the project area but outside the exclusion zone and thus prepare 
for potential shutdowns of activity should those marine mammals 
approach the exclusion zone. However, the primary purpose of ZOI 
monitoring is to allow documentation of incidents of Level B 
harassment; ZOI monitoring is discussed in greater detail later (see 
Monitoring and Reporting). The modeled radial distances for the ZOI for 
impact pile driving of 24-inch square concrete piles is 46 m. NMFS 
proposes a 50 m Level B zone for harbor seals and California sea lions.
    In order to document observed incidents of harassment, monitors 
will record all marine mammals observed within the ZOI. Due to the 
relatively small ZOI and to the monitoring locations chosen by Chevron 
we expect that two monitors will be able to observe the entire ZOI.
    Ramp up/Soft-start--A ``soft-start'' technique is intended to allow 
marine mammals to vacate the area before the pile driver reaches full 
power. For impact driving, an initial set of three strikes would be 
made by the hammer at reduced energy, followed by a 30-sec waiting 
period, then two subsequent three- strike sets before initiating 
continuous driving. 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 thirty minutes or longer.
    Pile Caps/Cushions--Chevron will employ the use of pile caps or 
cushions as sound attenuation devices to reduce impacts from sound 
exposure during impact pile driving.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means 
effecting the least practicable impact on the affected species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance.

Monitoring and Reporting

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

[[Page 15040]]

    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the 
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) 
populations, species, or stocks.
     Effects on marine mammal habitat (e.g., marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.
    Chevron will collect sighting data and will record behavioral 
responses to construction activities for marine mammal species observed 
in the project location during the period of activity. Monitoring will 
be conducted by qualified marine mammal observers (MMO), who are 
trained biologists, with the following minimum qualifications:
     Independent observers (i.e., not construction personnel) 
are required;
     At least one observer must have prior experience working 
as an observer;
     Other observers may substitute education (undergraduate 
degree in biological science or related field) or training for 
experience;
     Ability to conduct field observations and collect data 
according to assigned protocols;
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates 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;
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary; and
     NMFS will require submission and approval of observer CVs.
    Chevron will monitor the exclusion zones and Level B harassment 
zone before, during, and after pile driving, with at least two 
observers located at the best practicable vantage points. Based on our 
requirements, the Marine Mammal Monitoring Plan would implement the 
following procedures for pile driving:
     During observation periods, observers will continuously 
scan the area for marine mammals using binoculars and the naked eye;
     Monitoring shall begin 30 minutes prior to impact pile 
driving;
     Observers will conduct observations, meet training 
requirements, fill out data forms, and report findings in accordance 
with this IHA;
     If the exclusion zone is obscured by fog or poor lighting 
conditions, pile driving will not be initiated until the exclusion zone 
is clearly visible. Should such conditions arise while impact driving 
is underway, the activity would be halted;
     Observers will be in continuous contact with the 
construction personnel via two-way radio. A cellular phone will be used 
for back-up communications and for safety purposes;
     Observers will implement mitigation measures including 
monitoring of the proposed shutdown and monitoring zones, clearing of 
the zones, and shutdown procedures; and
     At the end of the pile-driving day, post-construction 
monitoring will be conducted for 30 minutes beyond the cessation of 
pile driving.

Data Collection

    We require that observers use approved data forms. Among other 
pieces of information, chevron will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile being driven, a description of specific actions that ensued, 
and resulting behavior of the animal, if any. In addition, Chevron will 
attempt to distinguish between the number of individual animals taken 
and the number of incidents of take, when possible. We require that, at 
a minimum, that the following information be recorded on sighting 
forms:
     Date and time that permitted construction activity begins 
or ends;
     Weather parameters (e.g., percent cloud cover, percent 
glare, visibility) and Beaufort sea state;
     Species, numbers, and, if possible, sex and age class of 
observed marine mammals;
     Construction activities occurring during each sighting;
     Marine mammal behavior patterns observed, including 
bearing and direction of travel;
     Specific focus should be paid to behavioral reactions just 
prior to, or during, soft-start and shutdown procedures;
     Location of marine mammal, distance from observer to the 
marine mammal, and distance from pile driving activities to marine 
mammals;
     Record of whether an observation required the 
implementation of mitigation measures, including shutdown procedures 
and the duration of each shutdown; and
     Other human activity in the area. Record the hull numbers 
of fishing vessels if possible.

Reporting Measures

    Chevron shall submit a draft report to NMFS within 90 days of the 
completion of marine mammal monitoring, or 60 days prior to the 
issuance of any subsequent IHA for this project (if required), 
whichever comes first. The annual report would detail the monitoring 
protocol, summarize the data recorded during monitoring, and estimate 
the number of marine mammals that may have been harassed. If no 
comments are received from NMFS within 30 days, the draft final report 
will become final. If comments are received, a final report must be 
submitted up to 30 days after receipt of comments. Reports shall 
contain the following information:
     Summaries of monitoring effort (e.g., total hours, total 
distances, and marine mammal distribution through the study period, 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals);
     Analyses of the effects of various factors influencing 
detectability of

[[Page 15041]]

marine mammals (e.g., sea state, number of observers, and fog/glare); 
and
     Species composition, occurrence, and distribution of 
marine mammal sightings, including date, numbers, age/size/gender 
categories (if determinable), and group sizes.
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury (Level A harassment), serious injury or 
mortality (e.g., ship-strike, gear interaction, and/or entanglement), 
Chevron would immediately cease the specified activities and 
immediately report the incident to the Office of Protected Resources, 
NMFS, and the West Coast Regional Stranding Coordinator. The report 
would include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved (if applicable);
     Vessel's speed during and leading up to the incident (if 
applicable);
     Description of the incident;
     Status of all sound source used in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with Chevron to 
determine necessary actions to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. Chevron would not be able 
to resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that Chevron discovers an injured or dead marine 
mammal, and the lead MMO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
Chevron would immediately report the incident to the Office of 
Protected Resources, NMFS, and the West Coast Regional Stranding 
Coordinator. The report would include the same information identified 
in the section above. Activities would be able to continue while NMFS 
reviews the circumstances of the incident. NMFS would work with Chevron 
to determine whether modifications in the activities are appropriate.
    In the event that Chevron discovers an injured or dead marine 
mammal, and the lead MMO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), Chevron would report the incident 
to Office of Protected Resources, NMFS, and West Coast Regional 
Stranding Coordinator, within 24 hours of the discovery. Chevron would 
provide photographs or video footage (if available) or other 
documentation of the stranded animal sighting to NMFS and the Marine 
Mammal Stranding Network. Pile driving activities would be permitted to 
continue.

Negligible Impact Analysis and Determination

    NMFS has defined negligible impact as ``an impact resulting from 
the specified activity that cannot be reasonably expected to, and is 
not reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival'' (50 CFR 216.103). 
A negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of takes, alone, is not 
enough information on which to base an impact determination. In 
addition to considering the authorized 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, etc.), as well as effects on habitat, the status 
of the affected stocks, and the likely effectiveness of the mitigation. 
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 these analyses 
via their impacts on the environmental baseline (e.g., as reflected in 
the regulatory status of the species, population size and growth rate 
where known, ongoing sources of human-caused mortality, or ambient 
noise levels).
    To avoid repetition, this introductory discussion of our analyses 
applies to all the species listed in Table 7 given that the anticipated 
effects of Chevron's construction activities involving impact pile 
driving on marine mammals are expected to be relatively similar in 
nature. There is no information about the nature or severity of the 
impacts, or the size, status, or structure of any species or stock that 
would lead to a different analysis for this activity, or else species-
specific factors would be identified and analyzed.
    Impact pile driving activities associated with the proposed 
project, as outlined previously, have the potential to disturb or 
displace marine mammals. Specifically, the specified activities may 
result in take, in the form of Level B harassment (behavioral 
disturbance) from underwater sounds generated from pile driving. 
Potential takes could occur if individuals of these species are present 
in the ensonified zone when in-water construction is under way.
    No marine mammal stocks for which incidental take authorization is 
proposed are listed as threatened or endangered under the ESA or 
determined to be strategic or depleted under the MMPA. No injuries or 
mortalities are anticipated to occur as a result of Chevron's impact 
pile driving activities. The relatively low marine mammal density and 
small shutdown zones make injury takes of marine mammals unlikely. In 
addition, the Level A exclusion zones would be thoroughly monitored 
before the proposed impact pile driving occurs and driving activities 
would be would be postponed if a marine mammal is sighted entering the 
exclusion zones. The likelihood that marine mammals will be detected by 
trained observers is high under the environmental conditions described 
for the proposed project. The employment of the soft-start mitigation 
measure would also allow marine mammal in or near the ZOI or exclusion 
zone to move away from the impact driving sound source. Therefore, the 
proposed mitigation and monitoring measures are expected to eliminate 
the potential for injury and reduce the amount and intensity of 
behavioral harassment. Furthermore, the pile driving activities 
analyzed here are similar to, or less impactful than, numerous 
construction activities conducted in other similar locations which have 
taken place with no reported injuries or mortality to marine mammals, 
and no known long-term adverse consequences from behavioral harassment.
    The takes that are anticipated and authorized are expected to be 
limited to short-term Level B harassment (behavioral and TTS) as only 
eight piles will be driven over 4 days with each pile requiring 
approximately 20 minutes of driving time. Marine mammals

[[Page 15042]]

present near the action area and taken by Level B harassment would most 
likely show overt brief disturbance (e.g. startle reaction) and 
avoidance of the area from elevated noise level during pile driving. A 
few marine mammals could experience TTS if they move into the Level B 
ZOI. However, TTS is a temporary loss of hearing sensitivity when 
exposed to loud sound, and the hearing threshold is expected to recover 
completely within minutes to hours. Therefore, it is not considered an 
injury. Repeated exposures of individuals to levels of sound that may 
cause Level B harassment are unlikely to significantly disrupt foraging 
behavior. 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.
    The proposed project is not expected to have significant adverse 
effects on affected marine mammals' habitat. While EFH for several 
species does exist in the proposed project area, the proposed 
activities would not permanently modify existing marine mammal habitat. 
The activities may cause fish to leave the area temporarily. This could 
impact marine mammals' foraging opportunities in a limited portion of 
the foraging range; but, because of the short duration of the 
activities and the relatively small area of affected habitat, the 
impacts to marine mammal habitat are not expected to cause significant 
or long-term negative consequences.
    In summary, this negligible impact analysis is founded on the 
following factors: (1) The possibility of non-auditory injury, serious 
injury, or mortality may reasonably be considered discountable; (2) the 
anticipated incidents of Level B harassment consist of, at worst, TTS 
or temporary modifications in behavior; (3) the short duration of in-
water construction activities (4 days, 160 minutes total driving time); 
(4) limited spatial impacts to marine mammal habitat; and (5) the 
presumed efficacy of the proposed mitigation measures in reducing the 
effects of the specified activity to the level of least practicable 
impact. In combination, we believe that these factors, as well as the 
available body of evidence from other similar activities, demonstrate 
that the potential effects of the specified activity will have only 
short-term effects on individuals. The specified activity is not 
expected to impact rates of recruitment or survival and will therefore 
not result in population-level impacts.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, NMFS compares the number of 
individuals taken to the most appropriate estimation of the relevant 
species or stock size in our determination of whether an authorization 
is limited to small numbers of marine mammals.
    The numbers of animals authorized to be taken would be considered 
small relative to the relevant stocks or populations (<0.01 percent for 
both species as shown in Table 7) even if each estimated taking 
occurred to a new individual. However, the likelihood that each take 
would occur to a new individual is extremely low. Further, these takes 
are likely to occur only within some small portion of the overall 
regional stock.

 Table 7--Population Abundance Estimates, Total Proposed Level B Take, and Percentage of Population That may be
                     Taken for the Potentially Affected Species During the Proposed Project
----------------------------------------------------------------------------------------------------------------
                                                                                                   Percentage of
                             Species                                Abundance *   Total proposed     stock or
                                                                                   Level B take     population
----------------------------------------------------------------------------------------------------------------
Harbor seal.....................................................       30,968\1\              24           <0.01
California sea lion (U.S. Stock)................................         296,750               2           <0.01
----------------------------------------------------------------------------------------------------------------
* Abundance estimates are taken from the 2015 U.S. Pacific Marine Mammal Stock Assessments (Carretta et al.,
  2016).
\1\ California stock abundance estimate

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

Unmitigable Adverse Impact Analysis and Determination

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

Endangered Species Act (ESA)

    Issuance of an MMPA authorization requires compliance with the ESA. 
No incidental take of ESA-listed species is proposed for authorization 
or expected to result from this activity. Therefore, NMFS has 
determined that consultation under section 7 of the ESA is not required 
for this action.

National Environmental Policy Act (NEPA)

    Issuance of an MMPA authorization requires compliance with NEPA. 
NMFS will pursue categorical exclusion (CE) status under NEPA for this 
action. As such, we have preliminary determined the issuance of the 
proposed IHA is consistent with categories of activities identified in 
CE B4 of the Companion Manual for NAO 216-6A and we have not identified 
any extraordinary circumstances listed in Chapter 4 of the Companion 
Manual for NAO 216-6A that would preclude this categorical exclusion. 
If, at the close of the public comment period, NMFS has not received 
comments or information contradictory to our initial CE determination, 
we will prepare a CE memorandum for the record.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to Chevron for conducting

[[Page 15043]]

impact pile driving at the MWEP in San Francisco Bay. This section 
contains a draft of the IHA itself. The wording contained in this 
section is proposed for inclusion in the IHA (if issued).
    1. This Incidental Harassment Authorization (IHA) is valid from 
January 1, 2018 through December 31, 2018.
    2. This Authorization is valid only for in-water construction work 
associated with the Chevron Long Wharf Maintenance and Efficiency 
Project.
    3. General Conditions.
    (a) A copy of this IHA must be in the possession of Chevron, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking by Level B harassment include 
Pacific harbor seal (Phoca vitulina) and California sea lion (Zalophus 
californianus). Table 1 shows the number of takes permitted for each 
species.

                  Table 8--Total Proposed Level B Takes
------------------------------------------------------------------------
                                                          Total proposed
                         Species                           Level B takes
------------------------------------------------------------------------
Harbor seal.............................................              24
California sea lion.....................................               2
------------------------------------------------------------------------

    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b). See Table 1 above.
    (d) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in condition 3(b) or any taking of 
any other species of marine mammal is prohibited and may result in the 
modification, suspension, or revocation of this IHA.
    (e) Chevron shall conduct briefings between construction 
supervisors and crews, marine mammal monitoring team, and staff prior 
to the start of all in-water pile driving, and when new personnel join 
the work.
    4. Mitigation Measures.
    The holder of this Authorization is required to implement the 
following mitigation measures:
    (a) Time Restrictions: For all in-water pile driving activities, 
Chevron shall operate only during daylight hours.
    (b) Establishment of Shutdown zone: For all pile driving 
activities, Chevron shall establish shutdown zones of 50 m for harbor 
porpoises and gray whales and 15 m for harbor seals and California sea 
lions.
    (c) Establishment of Level B harassment zone (ZOI): For all pile 
driving activities, Chevron shall establish a ZOI of 50 m for species 
listed in 3(b).
    (d) The shutdown zone and ZOI shall be monitored throughout the 
time required to install a pile. If a harbor seal or California sea 
lion is observed entering the ZOI, a Level B exposure shall be recorded 
and behaviors documented. That pile segment shall be completed without 
cessation, unless the animal approaches the shutdown zone. Pile 
installation shall be halted immediately before the animal enters the 
Level A zone.
    (e) If any marine mammal species other than those listed in 
condition 3(b) enters or approaches the ZOI zone all activities shall 
be shut down until the animal is seen leaving the ZOI or it has not 
been seen in the shutdown zone for 30 minutes for cetaceans and 15 
minutes for pinnipeds.
    (f) Use of Ramp Up/Soft Start.
    (i) The project shall utilize soft start techniques for all impact 
pile driving. We require Chevron to implement an initial set of three 
strikes would be made by the hammer at reduced energy, followed by a 
30-second waiting period, then two subsequent three- strike sets.
    (ii) Soft start shall be required at the beginning of each day's 
impact pile driving work and at any time following a cessation of pile 
driving of 30 minutes or longer.
    (iii) If a marine mammal is present within a shutdown zone, ramping 
up shall be delayed until the animal(s) leaves the relevant shutdown 
zone. Activity shall begin only after the MMO has determined, through 
sighting, that the animal(s) has moved outside the relevant shutdown 
zone or it has not been seen in the shutdown zone for 30 minutes for 
cetaceans and 15 minutes for pinnipeds.
    (iv) If species listed in 3(b) is present in the Level B harassment 
zone, ramping up shall begin and a Level B take shall be documented. 
Ramping up shall occur when these species are in the Level B harassment 
zone whether they entered the Level B zone from the Level A zone, or 
from outside the project area.
    (g) Pile caps or cushions shall be used during all impact pile-
driving activities.
    (h) 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.
    5. Monitoring and Reporting.
    The holder of this Authorization is required to submit a report to 
NMFS within 90 days of the completion of marine mammal monitoring, or 
60 days prior to the issuance of any subsequent IHA for this project 
(if required), whichever comes first.
    (a) Visual Marine Mammal Monitoring and Observation.
    (i) At least two individuals meeting the minimum qualifications 
below shall monitor the shutdown zones and Level B harassment zone from 
best practicable vantage points during impact pile driving,
    (ii) Requirements when choosing MMOs 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 may substitute education (undergraduate degree 
in biological science or related field) or training for experience.
    d. Ability to conduct field observations and collect data according 
to assigned protocols
    e. Experience or training in the field identification of marine 
mammals, including the identification of behaviors.
    f. Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations.
    g. 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.
    h. 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.
    i. Chevron shall submit observer CVs for NMFS approval.
    (iii) If the exclusion zone is obscured by fog or poor lighting 
conditions, pile driving shall not be initiated until the exclusion 
zone is clearly visible. Should such conditions arise while impact 
driving is underway, the activity shall be halted.
    (iv) At the end of the pile-driving day, post-construction 
monitoring will be conducted for 30 minutes beyond the cessation of 
pile driving
    (b) Data Collection.
    (i) Observers are required to use approved data forms. Among other 
pieces of information, Chevron shall record detailed information about 
any implementation of shutdowns,

[[Page 15044]]

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, Chevron shall attempt to distinguish between the 
number of individual animals taken and the number of incidents of take. 
At a minimum, the following information shall be collected on the 
sighting forms:
    a. Date and time that monitored activity begins or ends;
    b. Weather parameters (e.g., percent cloud cover, percent glare, 
visibility) and Beaufort sea state.
    c. Species, numbers, and, if possible, sex and age class of 
observed marine mammals;
    d. Construction activities occurring during each sighting;
    e. Marine mammal behavior patterns observed, including bearing and 
direction of travel;
    f. Specific focus should be paid to behavioral reactions just prior 
to, or during, soft-start and shutdown procedures;
    g. Location of marine mammal, distance from observer to the marine 
mammal, and distance from pile driving activities to marine mammals;
    h. Record of whether an observation required the implementation of 
mitigation measures, including shutdown procedures and the duration of 
each shutdown; and
    i. Other human activity in the area.
    (c) Reporting Measures.
    (i) In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA, 
such as an injury (Level A harassment), serious injury or mortality 
(e.g., ship-strike, gear interaction, and/or entanglement), Chevron 
would immediately cease the specified activities and immediately report 
the incident to the Office of Protected Resources, NMFS, and the West 
Coast Regional Stranding Coordinator. The report would include the 
following information:
    a. Time, date, and location (latitude/longitude) of the incident;
    b. Name and type of vessel involved;
    c. Vessel's speed during and leading up to the incident;
    d. Description of the incident;
    e. Status of all sound source use in the 24 hours preceding the 
incident;
    f. Water depth;
    g. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    h. Description of all marine mammal observations in the 24 hours 
preceding the incident;
    i. Species identification or description of the animal(s) involved;
    j. Fate of the animal(s); and
    k. Photographs or video footage of the animal(s) (if equipment is 
available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with Chevron to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. Chevron would not be able 
to resume their activities until notified by NMFS via letter, email, or 
telephone.
    (ii) In the event that Chevron discovers an injured or dead marine 
mammal, and the lead MMO determines that the cause of the injury or 
death is unknown and the death is relatively recent (i.e., in less than 
a moderate state of decomposition as described in the next paragraph), 
Chevron would immediately report the incident to the Office of 
Protected Resources, NMFS, and the West Coast Regional Stranding 
Coordinator. The report would include the same information identified 
in the paragraph above. Activities would be able to continue while NMFS 
reviews the circumstances of the incident. NMFS would work with Chevron 
to determine whether modifications in the activities are appropriate.
    (iii) In the event that Chevron discovers an injured or dead marine 
mammal, and the lead MMO determines that the injury or death is not 
associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), Chevron would report the incident 
to the Office of Protected Resources, NMFS, and the West Coast Regional 
Coordinator, within 24 hours of the discovery. Chevron would provide 
photographs or video footage (if available) or other documentation of 
the stranded animal sighting to NMFS and the Marine Mammal Stranding 
Network.
    6. 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

    NMFS requests comment on our analysis, the draft authorization, and 
any other aspect of the Notice of Proposed IHA for impact pile driving 
associated with Chevron's Long Wharf Maintenance and Efficiency Project 
from January 1, 2018 through December 31, 2018. Please include with 
your comments any supporting data or literature citations to help 
inform our final decision on Chevron's request for an MMPA 
authorization.

    Dated: March 17, 2017.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2017-05843 Filed 3-23-17; 8:45 am]
 BILLING CODE 3510-22-P