[Federal Register Volume 82, Number 149 (Friday, August 4, 2017)]
[Notices]
[Pages 36360-36384]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2017-16453]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XF541


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Pier Replacement Project in San 
Diego, CA

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

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

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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for 
authorization to take marine mammals incidental to construction and 
demolition activities as part of a pier replacement project. Pursuant 
to the Marine Mammal Protection Act (MMPA), NMFS is requesting comments 
on its proposal to issue an incidental harassment authorization (IHA) 
to the Navy to incidentally take marine mammals, by Level B Harassment 
only, during the specified activity. NMFS will consider public comments 
prior to making any final decision on the issuance of the requested 
MMPA authorizations and agency responses will be summarized in the 
final notice of our decision.

DATES: Comments and information must be received no later than 
September 5, 2017.

ADDRESSES: Comments on the application should be addressed to Jolie 
Harrison, Chief, Permits and Conservation Division, Office of Protected 
Resources, National Marine Fisheries Service. Physical comments should 
be sent to 1315 East-West Highway, Silver Spring, MD 20910 and 
electronic comments should be sent to [email protected].
    Instructions: NMFS is not responsible for comments sent by any 
other method, to any other address or individual, or received after the 
end of the comment period. Comments received electronically, including 
all attachments, must not exceed a 25-megabyte file size. Attachments 
to electronic comments will be accepted in Microsoft Word or Excel or 
Adobe PDF file formats only. All comments received are a part of the 
public record and will generally be posted to 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: Laura McCue, Office of Protected 
Resources, NMFS, (301) 427-8401. Electronic copies of the application 
and supporting documents, as well as a list of the references cited in 
this document, may be obtained online at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing these 
documents, please call the contact listed above.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce (as delegated to NMFS) to allow, upon 
request, the

[[Page 36361]]

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

National Environmental Policy Act (NEPA)

    To comply with the National Environmental Policy Act of 1969 (NEPA; 
42 U.S.C. 4321 et seq.) and NOAA Administrative Order (NAO) 216-6A, 
NMFS must review our proposed action (i.e., the issuance of an 
incidental harassment authorization) with respect to potential impacts 
on the human environment.
    This action is consistent with categories of activities identified 
in CE B4 of the Companion Manual for NOAA Administrative Order 216-6A, 
which do not individually or cumulatively have the potential for 
significant impacts on the quality of the human environment and for 
which we have not identified any extraordinary circumstances that would 
preclude this categorical exclusion. Accordingly, NMFS has 
preliminarily determined that the issuance of the proposed IHA 
qualifies to be categorically excluded from further NEPA review.
    We will review all comments submitted in response to this notice 
prior to concluding our NEPA process or making a final decision on the 
IHA request.

Summary of Request

    On June 19, 2017, we received a request from the Navy for an IHA to 
take marine mammals incidental to pile installation and demolition 
associated with a pier replacement project in San Diego Bay at Naval 
Base Point Loma in San Diego, CA (NBPL), including a separate 
monitoring plan. The Navy also submitted a draft monitoring report on 
June 13, 2017, pursuant to requirements of the previous IHA. These 
final application and monitoring plan were deemed adequate and complete 
on July 20, 2017. The pier replacement project is planned to occur over 
multiple years; this proposed IHA would cover only the fifth year of 
work and would be valid for a period of one year from the date of 
issuance. Hereafter, use of the generic term ``pile driving'' may refer 
to both pile installation and removal unless otherwise noted. The 
Navy's request is for take of nine species of marine mammals by Level B 
harassment. Neither the Navy nor NMFS expect mortality to result from 
this activity and, therefore, an IHA is appropriate.
    Monitoring reports are available online at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm and provide environmental 
information related to proposed issuance of this IHA for public review 
and comment.
    This proposed IHA would cover one year of a larger project for 
which the Navy obtained prior IHAs and this request for take 
authorization is for the fifth year of the project, following the IHAs 
issued effective from October 8, 2016, through October 7, 2017 (81 FR 
66628), September 1, 2013, through August 31, 2014 (78 FR 44539), from 
October 8, 2014, through October 7, 2015 (79 FR 65378), and from 
October 8, 2015, through October 7, 2016 (80 FR 62032). The Navy 
complied with all the requirements (e.g., mitigation, monitoring, and 
reporting) of the previous IHA. Monitoring reports are available online 
at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm and provide 
environmental information related to proposed issuance of this IHA for 
public review and comment.

Description of the Specified Activity

Overview

    NBPL provides berthing and support services for Navy submarines and 
other fleet assets. The existing fuel pier serves as a fuel depot for 
loading and unloading tankers and Navy underway replenishment vessels 
that refuel ships at sea (``oilers''), as well as transferring fuel to 
local replenishment vessels and other small craft operating in San 
Diego Bay, and is the only active Navy fueling facility in southern 
California. Portions of the pier are over one hundred years old, while 
the newer segment was constructed in 1942. The pier as a whole is 
significantly past its design service life and does not meet current 
construction standards.
    The Navy plans to demolish and remove the existing pier and 
associated pipelines and appurtenances while simultaneously replacing 
it with a generally similar structure that meets relevant standards for 
seismic strength and is designed to better accommodate modern Navy 
ships. Demolition and construction are planned to occur in two phases 
to maintain the fueling capabilities of the existing pier while the new 
pier is being constructed. During the fifth year of construction (the 
specified activity considered under this proposed IHA), the Navy 
anticipates construction at two locations: The fuel pier area and at 
the Naval Mine and Anti-Submarine Warfare Command (NMAWC), where the 
Navy's Marine Mammal Program (MMP) was temporarily moved during fuel 
pier construction (see Figure 1-1 in the Navy's application). At the 
fuel pier, the Navy anticipates finishing all the demolition, including 
removal of 180 square precast (PC) concrete and poly-concrete piles of 
varying sizes up to 24-in using a hydraulic pile cutter; cutting 30 66-
in and 5 84-in concrete-filled steel caissons with a diamond wire saw; 
and removing 12 30-in steel piles by cutting with a plasma torch. Only 
the hydraulic pile cutting and diamond saw cutting of caissons reach 
Level B acoustic thresholds.
    At the NMAWC, twenty-three 16-in diameter PC concrete guide piles 
would be driven (by vibratory and/or impact hammer) to restore gangway 
access to the recreational marina. Sixty-four 16-in diameter round PC 
concrete guide piles will be removed at NMAWC by jetting followed by 
dry-pulling; dry pulling does not reach the Level B acoustic 
thresholds. Table 1 summarizes the construction activities during the 
fifth year of the Navy's project.

[[Page 36362]]



 Table 1--Construction Proposed To Be Complete During Fifth Year of NBPL
                                 Project
------------------------------------------------------------------------
           Location and pile type or structure                Number
------------------------------------------------------------------------
                           Removal/Demolition
------------------------------------------------------------------------
Pier 180 (Fuel Pier):
    Poly-concrete and PC concrete piles up to 24-in                  180
     square.............................................
    66'' concrete filled steel caissons.................              30
    84'' concrete filled steel caissons.................               5
    30'' steel at temporary south dolphin...............              12
        Total--Pier 180 (Fuel Pier).....................             227
NMAWC:
    Extract 16'' PC round concrete......................              64
                                                         ---------------
        Total--NMAWC....................................              64
                                                         ---------------
            Total Piles Removed.........................             291
------------------------------------------------------------------------
                              Installation
------------------------------------------------------------------------
NMAWC:
    16'' PC concrete guide piles........................              23
                                                         ---------------
            Total Piles Removed.........................              23
------------------------------------------------------------------------
Notes: PC = precast.

    The proposed actions with the potential to incidentally harass 
marine mammals within the waters adjacent to NBPL are vibratory and 
impact pile installation and certain demolition (i.e., pile removal) 
techniques. Concurrent use of multiple pile driving rigs is not 
planned.

Dates and Duration

    The proposed activities that would be authorized by this IHA, 
during the fifth year of work associated with the fuel pier project, 
would occur for one year from the date of issuance of this proposed 
IHA. Under the terms of a memorandum of understanding (MOU) between the 
Navy and the U.S. Fish and Wildlife Service (FWS), all noise- and 
turbidity-producing in-water activities in designated least tern 
foraging habitat are to be avoided during the period when least terns 
are present and engaged in nesting and foraging (a window from 
approximately May 1 through September 15). However, it is possible that 
in-water work not expected to result in production of significant noise 
or turbidity (e.g., demolition activities) could occur at any time 
during the period of validity of this proposed IHA. The conduct of any 
such work would be subject to approval from FWS under the terms of the 
MOU. We expect that in-water construction work would primarily occur 
from October through April. Pile driving would occur during normal 
working hours (approximately 7 a.m. to 6 p.m.), and would not occur 
earlier than 45 minutes after sunrise or later than 45 minutes before 
sunset.

Specific Geographic Region

    NBPL is located on the peninsula of Point Loma near the mouth and 
along the northern edge of San Diego Bay (see Figures 1-1 and 1-2 in 
the Navy's application). San Diego Bay is a narrow, crescent-shaped 
natural embayment oriented northwest-southeast with an approximate 
length of 24 kilometers (km) and a total area of roughly 4,500 hectares 
(ha). The width of the bay ranges from 0.3 to 5.8 km, and depths range 
from 23 meters (m) mean lower low water (MLLW) near the tip of Ballast 
Point to less than 2 m at the southern end (see Figure 2-1 of the 
Navy's application). San Diego Bay is a heavily urbanized area with a 
mix of industrial, military, and recreational uses. The northern and 
central portions of the bay have been shaped by historic dredging to 
support large ship navigation. Dredging occurs as necessary to maintain 
constant depth within the navigation channel. Outside the navigation 
channel, the bay floor consists of platforms at depths that vary 
slightly. Sediments in northern San Diego Bay are relatively sandy as 
tidal currents tend to keep the finer silt and clay fractions in 
suspension, except in harbors and elsewhere in the lee of structures 
where water movement is diminished. Much of the shoreline consists of 
riprap and manmade structures. San Diego Bay is heavily used by 
commercial, recreational, and military vessels, with an average of over 
80,000 vessel movements (in or out of the bay) per year (not including 
recreational boating within the Bay) (see Table 2-2 of the Navy's 
application). For more information about the specific geographic 
region, please see section 2.3 of the Navy's application.

Detailed Description of Activities

    In order to provide context, we described the entire project in our 
Federal Register notice of proposed authorization associated with the 
first-year IHA (78 FR 30873; May 23, 2013). Please see that document 
for an overview of the entire fuel pier replacement project, or see the 
Navy's Environmental Assessment (2013) for more detail. Here, we 
provide an overview of relevant construction methods before describing 
only the specific project portions scheduled for completion during the 
fifth work window. Please see Section 1 of the Navy's application for 
full detail of construction scheduling for this period. For the fifth 
year of work, approximately 23 concrete piles would be installed at 
NMAWC. The Navy does not anticipate needing future IHAs related to 
completion of construction at NBPL, but would apply for a sixth IHA if 
construction is not completed under this IHA.
    Methods, Pile Installation--Vibratory hammers, which can be used to 
either install or extract a pile, contain a system of counter-rotating 
eccentric weights powered by hydraulic motors and are designed in such 
a way that horizontal vibrations cancel out, while vertical vibrations 
are transmitted into the pile. The pile driving machine is lifted and 
positioned over the pile by means of an excavator or crane, and is 
fastened to the pile by a clamp and/or bolts. The vibrations produced 
cause liquefaction

[[Page 36363]]

of the substrate surrounding the pile, enabling the pile to be 
extracted or driven into the ground using the weight of the pile plus 
the hammer. Impact hammers use a rising and falling piston to 
repeatedly strike a pile and drive it into the ground.
    Non-steel piles are typically impact-driven for their entire 
embedment depth, in part because non-steel piles are often displacement 
piles (as opposed to pipe piles) and require some impact to allow 
substrate penetration. However, jetting may be used to advance 
displacement piles to a certain embedment depth. Pile jetting utilizes 
a directed flow of pressurized water to assist in pile placement. The 
jetting technique liquefies the soils at the pile tip during pile 
placement, reducing the friction between adjacent sub-grade soil 
particles around the water jet. This greatly decreases the bearing 
capacity of the soils below the pile tip, causing the pile to descend 
toward its final tip elevation with much less soil resistance, largely 
under its own weight.
    Methods, Pile Removal--There are multiple methods for pile removal. 
During previous demolition, piles were generally removed by cutting at 
the mudline, which can be accomplished in various ways. Piles are 
expected to be removed during this fifth-year IHA primarily using a 
pile cutter, which is a bladed hydraulic device that shears the pile 
off. The preferred method of removing the caisson elements is to cut 
them at the mudline and then into two sections using a diamond wire 
cutting saw. Existing caisson elements would be removed with a 
clamshell, which is a dredging bucket consisting of two similar halves 
that open/close at the bottom and are hinged at the top. The clamshell 
would be used to grasp and lift large components.
    Piles may also be removed by simply dry pulling, or pulling after 
the pile has been loosened using a vibratory hammer or a pneumatic 
chipper. Jetting may be another option to loosen piles that could not 
be removed through the previous procedures. Pile removal is not 
generally expected to require the use of vibratory extraction or 
pneumatic chipping, and these methods are considered as contingency in 
the event other methods of extraction are not successful.
    Construction--Construction work during the proposed fifth year of 
activity would include driving of concrete piles to restore dock access 
at NMAWC following Navy Marine Mammal Program (MMP) removal from NMAWC. 
This work is expected to require a total of 25 days.
    Demolition--Demolition of the old pier will be completed now that 
the new pier is operational. Much of the demolition work will be above-
water, involving removal of the pier, pilings, plastic camels and 
fenders, but in-water structure removal will also occur, as described 
above under Methods, Pile Removal. The in-water portion of demolition 
work planned during the period of this proposed IHA is expected to 
require 156 days in total.
    NMAWC--As described above, the Navy also plans to return the MMP to 
its permanent location near the fuel pier, requiring extraction and 
installation of concrete piles to return the NMAWC site to its original 
condition. This work is expected to require 15 days.

Description of Work Accomplished

    During the first in-water work season (2013-14), two primary 
activities were conducted: Relocation of the MMP and the Indicator Pile 
Program (IPP). During the second in-water work season (2014-15), the 
IPP was concluded and simultaneous construction of the new pier and 
demolition of the old pier begun. Production pile driving continued 
during the third in-water work season (2015-16). During the fourth in-
water work season (2016-17) pile driving of fender piles and structural 
piles for the mooring dolphins for the new fuel pier was conducted, 
including two IPP piles, demolition of the old fuel pier, and pile 
driving and extraction at NMAWC.
    The Navy MMP, administered by Space and Naval Warfare Systems 
(SPAWAR) Command Systems Center (SSC), was moved approximately three 
kilometers to the NMAWC (see Figures 1-1 and 1-2 of the Navy's Year 1 
monitoring report). Although not subject to the MMPA, SSC's working 
animals were temporarily relocated so that they will not be affected by 
the project. Over the course of 25 in-water construction days from 
January 28 to March 13, 2014, the Navy removed thirty and installed 81 
concrete piles (12- and 16-in). See Table 3-2 of the Navy's Year 1 
monitoring report for details. Installation was accomplished via a D19-
42 American Pile Driving Equipment, Inc. (APE) diesel hammer with 
energy capacity of 23,566-42,800 ft-lbs and fitted with a hydraulic 
tripping cylinder with four adjustable power settings that could be 
reset while driving. Pile removal was accomplished by jetting and dead 
pull.
    The IPP was designed to validate the length of pile required and 
the method of installation (vibratory and impact) as well as to 
validate acoustic sound pressure levels of the various sizes and 
locations (i.e., shallow versus deeper water) of installed piles. Nine 
steel pipe test piles were vibratory- and impact-driven over ten work 
days from April 28 to May 15, 2014, including two 30-in and seven 36-in 
piles. All piles were initially installed using an APE Variable Moment 
250 VM Vibratory Hammer Extractor powered by a model 765 hydraulic 
power source creating a maximum driving force of 2,389 kilonewtons (269 
tons). Impact pile driving equipment consisted of a single acting 
diesel impact hammer model D62-22 DELMAG with energy capacity of 
76,899-153,799 ft-lbs and fitted with a hydraulic tripping cylinder 
with four adjustable power settings that could be reset while driving. 
One additional 36-in pile was installed in Spring 2015, under the Year 
2 IHA, to conclude the IPP.
    Production pile driving associated with construction of the new 
pier was begun in Fall 2014 and continued into Spring 2015. Both 
vibratory and impact driving was used, as described above, to install 
238 steel pipe piles (four 18-in, 31 30-in, and 203 36-in diameter). 
Hammers used were the same as those described above. Demolition 
activity began in Spring 2015, and included the removal of four 
caissons, eighteen concrete fender piles, and a portion of concrete 
decking from the existing fuel pier. In total, this work consisted of 
100 days of activity from October 16, 2014, through April 29, 2015. Of 
these 100 days of in-water work, 18 days involved only impact driving, 
15 days included only vibratory driving, and 65 days where both types 
of driving occurred. The remaining two days involved only demolition 
activities. Please see the Year 2 monitoring report for more 
information.
    Production pile driving continued in early 2016 during three 
distinct construction periods from January 11 through April 30, 2016, 
with 161 piles installed over the course of 50 days. Because most 
structural steel pipe piles were installed under the Year 2 IHA, this 
work primarily involved placement of non-structural concrete fender 
piles. Both vibratory and impact driving was used, as described above, 
to install 132 16-in polycarbonate coated concrete fender piles and 23 
24 x 30-in concrete fender piles. In addition, six 30-in steel pipe 
piles were installed as structural elements to support a mooring 
dolphin. Hammers used for the steel piles were the same as those 
described above. The 16-in concrete piles were driven using an APE 
single action diesel impact hammer model D25-32, with energy capacity 
of 29,484-58,245 ft-lbs and

[[Page 36364]]

fitted with a manual power level modulator and shut off trip. The 24 x 
30-in concrete piles were driven using an APE single action diesel 
impact hammer model D80-42, with energy capacity of 127,008-198,450 ft-
lbs and fitted with a manual power level modulator and shut off trip. 
No demolition occurred during this period. Of the 50 days of in-water 
work, 45 days involved only impact driving, two days included only 
vibratory driving, and three days where both types of driving occurred. 
Please see the Year 3 monitoring report for more information.
    Production pile driving during Year 4 construction, from October 8, 
2016 to April 30, 2017, included 68 piles of three types of piles 
driven with two different methods over 34 days: 30-in steel piles were 
driven with both vibratory and impact hammers, and the 24 x 30-in 
concrete and 16-in poly-concrete piles were installed with impact 
hammers. High pressure water jetting were used to ``pre-drill'' holes 
for the 24 x 30 in piles. In addition, Structural piles were installed 
for two dolphins to the south of the new fuel pier, fender piles were 
installed on the east and west sides of the new fuel pier as well as on 
one of the dolphins, and a single 16-inch poly-concrete pile (concrete 
pile lined with a polycarbonate outer sheath) was driven on the west 
side of the pier.
    Demolition during Year 4 included removal of the caissons from the 
north side of the old fuel pier, as well as removal of structural and 
fender piles sizes under, and adjacent to, the south and north sections 
of the old pier. Eighteen 84-in caissons were cut using a wire saw. A 
total of 278 piles were clipped, including 14-in, 18-in, and 24-in 
fender piles and 13-in polycarbonate and poly-concrete piles. Of the 69 
days of in-water work, 42 days involved pile clipping and 27 days 
involved pile cutting. Please see the Year 4 monitoring report for more 
information.
    Additional work may be conducted under the existing IHA between 
September 15 and October 7, 2017, in which case the submitted 
monitoring report would be amended as necessary.
    Proposed mitigation, monitoring, and reporting measures are 
described in detail later in this document (please see Proposed 
Mitigation and Proposed Monitoring and Reporting).

Description of Marine Mammals in the Area of the Specified Activity

    Species with the expected potential to be present during all or a 
portion of the in-water work window include the California sea lion 
(Zalophus californianus), harbor seal (Phoca vitulina richardii), 
northern elephant seal (Mirounga angustirostris), gray whale 
(Eschrichtius robustus), bottlenose dolphin (Tursiops truncatus 
truncatus), Pacific white-sided dolphin (Lagenorhynchus obliquidens), 
Risso's dolphin (Grampus griseus), and either short-beaked or long-
beaked common dolphins (Delphinus spp.). California sea lions are 
present year-round and are very common in the project area, while 
bottlenose dolphins and harbor seals are common and likely to be 
present year-round but with more variable occurrence in San Diego Bay. 
Gray whales may be observed in San Diego Bay sporadically during 
migration periods. The remaining species are known to occur in 
nearshore waters outside San Diego Bay, but are generally only rarely 
observed near or in the bay. However, recent observations indicate that 
these species may occur in the project area and therefore could 
potentially be subject to incidental harassment from the aforementioned 
activities.
    There are four marine mammal species which are either resident or 
have known seasonal occurrence in the vicinity of San Diego Bay, 
including the California sea lion, harbor seal, bottlenose dolphin, and 
gray whale (see Figures 3-1 through 3-4 and 4-1 in the Navy's 
application). In addition, common dolphins (see Figure 3-4 in the 
Navy's application), the Pacific white-sided dolphin, Risso's dolphin, 
and northern elephant seals are known to occur in deeper waters in the 
vicinity of San Diego Bay and/or have been observed within the bay 
during the course of this project's monitoring. Although the latter 
three species of cetacean would not generally be expected to occur 
within the project area, the potential for changes in occurrence 
patterns in conjunction with recent observations leads us to believe 
that authorization of incidental take is warranted. Common dolphins 
have been documented regularly at the Navy's nearby Silver Strand 
Training Complex, and were observed in the project area during previous 
years of project activity. The Pacific white-sided dolphin has been 
sighted along a previously used transect on the opposite side of the 
Point Loma peninsula (Merkel and Associates, 2008) and there were 
several observations of Pacific white-sided dolphins during Year 2 
monitoring. Risso's dolphin is fairly common in southern California 
coastal waters (e.g., Campbell et al., 2010), and could occur in the 
bay. Northern elephant seals are included based on their continuing 
increase in numbers along the Pacific coast (Carretta et al., 2016) and 
the likelihood that animals that reproduce on the islands offshore of 
Baja California and mainland Mexico--where the population is also 
increasing--could move through the project area during migration, as 
well as the observation of a juvenile seal near the fuel pier in April 
2015.
    Note that common dolphins could be either short-beaked (Delphinus 
delphis delphis) or long-beaked (D. delphis bairdii) subspecies. While 
it is likely that common dolphins observed in the project area would be 
long-beaked, as it is the most frequently stranded species in the area 
from San Diego Bay to the U.S.-Mexico border (Danil and St. Leger 
2011), the species distributions overlap and it is unlikely that 
observers would be able to differentiate them in the field. Therefore, 
we consider that any common dolphins observed--and any incidental take 
of common dolphins--could be either long- or short-beaked common 
dolphins.
    In addition, other species that occur in the Southern California 
Bight may have the potential for isolated occurrence within San Diego 
Bay or just offshore. In particular, a short-finned pilot whale 
(Globicephala macrorhynchus) was observed off Ballast Point, and a 
Steller sea lion (Eumetopias jubatus monteriensis) was seen in the 
project area during Year 2. These species are not typically observed 
near the project area and, unlike the previously mentioned species, we 
do not believe it likely that they will occur in the future. Given the 
unlikelihood of their exposure to sound generated from the project, 
these species are not considered further.
    Sections 3 and 4 of the application summarize available information 
regarding status and trends, distribution and habitat preferences, and 
behavior and life history, of the potentially affected species. 
Additional information regarding population trends and threats may be 
found in NMFS's Stock Assessment Reports (SAR; www.nmfs.noaa.gov/pr/sars/) and more general information about these species (e.g., physical 
and behavioral descriptions) may be found on NMFS's Web site 
(www.nmfs.noaa.gov/pr/species/mammals/).
    Table 2 lists all marine mammal species with expected potential for 
occurrence in the vicinity of NBPL during the project timeframe and 
summarizes key information, including regulatory status under the MMPA 
and ESA and potential biological removal (PBR), where known. See also 
Figures 3-1 through 3-5 of the Navy's application for observed 
occurrence of

[[Page 36365]]

marine mammals in the project area. For taxonomy, we follow Committee 
on Taxonomy (2016). PBR is defined by the MMPA as the maximum number of 
animals, not including natural mortalities, that may be removed from a 
marine mammal stock while allowing that stock to reach or maintain its 
optimum sustainable population (as described in NMFS's SARs). While no 
mortality is anticipated or authorized here, PBR and annual serious 
injury and mortality from anthropogenic sources are included here as 
gross indicators of the status of the species and other threats.
    Marine mammal abundance estimates presented in this document 
represent the total number of individuals that make up a given stock or 
the total number estimated within a particular study or survey area. 
NMFS's stock abundance estimates for most species represent the total 
estimate of individuals within the geographic area, if known, that 
comprises that stock. For some species, this geographic area may extend 
beyond U.S. waters. All managed stocks in this region are assessed in 
NMFS's U.S. 2016 stock assessment report (SARs) (e.g., NMFS 2016). All 
values presented in Table 2 are the most recent available at the time 
of publication and are available in the 2016 SAR (available online at 
www.nmfs.noaa.gov/pr/sars).

                                           Table 2--Marine Mammals Potentially Present in the Vicinity of NBPL
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                     Stock abundance  (CV,                        Relative occurrence in
              Species                         Stock             ESA/MMPA status;      Nmin, most  recent     PBR \3\   Annual M/   San Diego Bay; season
                                                              strategic  (Y/N) \1\  abundance  survey) \2\               SI \4\        of occurrence
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                          Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                  Family Eschrichtiidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Gray whale.........................  Eastern North Pacific.  -; N                   20,990 (0.05; 20,125;         624        132  Occasional migratory
                                                                                     2011).                                        visitor; winter.
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                            Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                   Family Delphinidae
--------------------------------------------------------------------------------------------------------------------------------------------------------
Bottlenose dolphin.................  California coastal....  -; N                   453 (0.06; 346; 2011).        2.7      >=2.0  Common; year-round.
Short-beaked common dolphin........  California/Oregon/      -; N                   969,861 (0.17;              8,393       >=40  Occasional; year-round
                                      Washington.                                    839,325; 2014).                               (but more common in
                                                                                                                                   warm season).
Long-beaked common dolphin.........  California............  -; N                   101,305 (0.49; 68,432;        657     >=35.4  Occasional; year-round
                                                                                     2014).                                        (but more common in
                                                                                                                                   warm season).
Pacific white-sided dolphin........  California/Oregon/      -; N                   26,814 (0.28; 21,195;         191        7.5  Uncommon; year-round.
                                      Washington.                                    2014).
Risso's dolphin....................  California/Oregon/      -; N                   6,336 (0.32; 4,817;            46      >=3.7  Rare; year-round (but
                                      Washington.                                    2014).                                        more common in cool
                                                                                                                                   season).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                         Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                      Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion................  U.S...................  -; N                   296,750 (n/a; 153,337;      9,200        389  Abundant; year-round.
                                                                                     2011).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                             Family Phocidae (earless seals)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Harbor seal........................  California............  -; N                   30,968 (n/a; 27,348;        1,641         43  Common; year-round.
                                                                                     2012).
Northern elephant seal.............  California breeding...  -; N                   179,000 (n/a; 81,368;       4,882        8.8  Rare; year-round.
                                                                                     2010).
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Endangered Species Act (ESA) status: Endangered (E), Threatened (T)/MMPA status: Depleted (D). A dash (-) indicates that the species is not listed
  under the ESA or designated as depleted under the MMPA. Under the MMPA, a strategic stock is one for which the level of direct human-caused mortality
  exceeds PBR (see footnote 3) or which is determined to be declining and likely to be listed under the ESA within the foreseeable future. Any species
  or stock listed under the ESA is automatically designated under the MMPA as depleted and as a strategic stock.
\2\ CV is coefficient of variation; Nmin is the minimum estimate of stock abundance. In some cases, CV is not applicable. For certain stocks 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.
\3\ Potential biological removal, defined by the MMPA as the maximum number of animals, not including natural mortalities, that may be removed from a
  marine mammal stock while allowing that stock to reach or maintain its optimum sustainable population size (OSP).
\4\ These values, found in NMFS' SARs, represent annual levels of human-caused mortality plus serious injury from all sources combined (e.g., commercial
  fisheries, subsistence hunting, ship strike). Annual M/SI often cannot be determined precisely and is in some cases presented as a minimum value.

    All species that could potentially occur in the proposed survey 
areas are included in Table 2. As described below, all eight species 
(with nine managed stocks) temporally and spatially co-occur with the 
activity to the degree that take is reasonably likely to occur, and we 
have proposed authorizing it.

[[Page 36366]]

Gray Whale

    Two populations of gray whales are recognized, Eastern and Western 
North Pacific (ENP and WNP). The two populations have historically been 
considered geographically isolated from each other; however, recent 
data from satellite-tracked whales indicates that there is some overlap 
between the stocks. Two WNP whales were tracked from Russian foraging 
areas along the Pacific rim to Baja California (Mate et al., 2011), 
and, in one case where the satellite tag remained attached to the whale 
for a longer period, a WNP whale was tracked from Russia to Mexico and 
back again (IWC, 2012). Between 22-24 WNP whales are known to have 
occurred in the eastern Pacific through comparisons of ENP and WNP 
photo-identification catalogs (IWC 2012; Weller et al., 2011; Burdin et 
al., 2011), and WNP animals comprised 8.1 percent of gray whales 
identified during a recent field season off of Vancouver Island (Weller 
et al., 2012). In addition, two genetic matches of WNP whales have been 
recorded off of Santa Barbara, CA (Lang et al., 2011). More recently, 
Urban et al. (2013) compared catalogs of photo-identified individuals 
from Mexico with photographs of whales off Russia and reported a total 
of 21 matches. Therefore, a portion of the WNP population is assumed to 
migrate, at least in some years, to the eastern Pacific during the 
winter breeding season.
    However, only ENP whales are expected to occur in the project area. 
The likelihood of any gray whale being exposed to project sound to the 
degree considered in this document is already low, as it would require 
a migrating whale to linger for an extended period of time, or for 
multiple migrating whales to linger for shorter periods of time. While 
such an occurrence is not unknown, it is uncommon. Further, of the 
approximately 20,000 gray whales migrating through the Southern 
California Bight, it is extremely unlikely that one found in San Diego 
Bay would be one of the approximately twenty WNP whales that have been 
documented in the eastern Pacific (less than one percent probability). 
The likelihood that a WNP whale would be exposed to elevated levels of 
sound from the specified activities is insignificant and discountable 
and WNP whales are not considered further in this document.
    Gray whale transitory occurrence inside San Diego Bay is sporadic 
and unpredictable. A mean group size of 2.9 gray whales was reported 
for both coastal (16 groups) and non-coastal (15 groups) areas around 
Southern California Bight. The largest group reported was nine animals. 
The largest group reported by U.S. Navy (in 1998) was 27 animals 
(Carretta et al., 2000). Gray whales are not expected in the project 
area except during the northward migration, when they are closest to 
the coast (Rice et al., 1981).

Bottlenose Dolphin

    The California coastal stock of bottlenose dolphin is distinct from 
the offshore population and is resident in the immediate (within 1 km 
of shore) coastal waters, occurring primarily between Point Conception, 
California, and San Quintin, Mexico. Occasionally, during warm-water 
incursions such as during the 1982-1983 El Ni[ntilde]o events, their 
range extends as far north as San Francisco Bay (Carretta et al., 
2017). They are commonly found in groups of 2 to 15 individuals and in 
larger groups offshore.
    Coastal bottlenose dolphins have occurred sporadically and in 
highly variable numbers and locations in San Diego Bay. Navy surveys 
showed that bottlenose dolphins were most commonly sighted in April, 
and there were more dolphins observed during El Ni[ntilde]o years.

Pacific White-Sided Dolphin

    Pacific white-sided dolphins are endemic to temperate waters of the 
North Pacific Ocean, and are common both on the high seas and along the 
continental margins (Carretta et al., 2014). Off the U.S. west coast, 
Pacific white-sided dolphins occur primarily in shelf and slope waters. 
Sighting patterns from aerial and shipboard surveys conducted in 
California, Oregon and Washington suggest seasonal north-south 
movements, with animals found primarily off California during the 
colder water months and shifting northward into Oregon and Washington 
as water temperatures increase in late spring and summer (Carretta et 
al., 2014).
    Pacific white-sided dolphins are uncommon in San Diego Bay, but 
observations of this species increased during El Ni[ntilde]o years. 
Monitoring during the Year 2 IHA documented 7 sightings of Pacific 
white-sided dolphins, comprising 27 individuals, with a mean group size 
of 3.85 individuals per sighting and an average of 0.28 individuals 
sighted per day of monitoring.

Common Dolphin

    Short-beaked common dolphins are the most abundant cetacean off 
California and are widely distributed between the coast and at least 
300 nmi offshore. In contrast, long-beaked common dolphins generally 
occur within 50 nmi of shore. Both species of common dolphin appear to 
shift their distributions seasonally and annually in response to 
oceanographic conditions and prey availability (Carretta et al., 2016). 
The long-beaked species apparently prefers shallower, warmer water than 
the short-beaked common dolphin (Perrin 2009). Both tend to be more 
abundant in coastal waters during warm-water months (Bearzi 2005).
    The occurrence of common dolphins inside San Diego Bay is uncommon 
(NAVFAC SW and POSD 2013). Small groups were observed briefly on 
several occasions in the northern part of the bay by Navy monitors 
during the IPP (May 2014). The animals were moving swiftly and could 
not be distinguished as to species, but the weight of evidence based on 
distributions of the two species and previous sightings of the long-
beaked species near San Diego is that they were probably long-beaked 
common dolphins.

California Sea Lion

    The entire population of California sea lions cannot be counted 
because all age and sex classes are never ashore at the same time. In 
lieu of counting all sea lions, pups are counted when all are ashore, 
in July during the breeding season, and the number of births is 
estimated from pup counts (Carretta et al., 2016). The size of the 
population is then estimated from the number of births and the 
proportion of pups in the population. Based on these censuses, the U.S. 
stock has generally increased from the early 1900s, to a current 
estimate of 296,750 (Carretta et al., 2016). There are indications that 
the California sea lion may have reached or is approaching carrying 
capacity, although more data are needed to confirm that leveling in 
growth persists (Carretta et al., 2016).
    The California sea lion is by far the most commonly-sighted 
pinniped species at sea or on land in the vicinity of NBPL and northern 
San Diego Bay. The Navy has conducted numerous marine mammal surveys 
overlapping the north San Diego Bay project area and the potential ZOI 
for impact and vibratory pile driving operations. California sea lions 
regularly occur on rocks, buoys and other structures, and especially on 
bait barges, although numbers vary greatly.

Harbor Seal

    Harbor seals are considered abundant throughout most of their range 
from Baja California to the eastern Aleutian

[[Page 36367]]

Islands. Peak numbers of harbor seals haul-out on land during late May 
to early June, which coincides with the peak of their molt. Harbor 
seals do not make extensive pelagic migrations, but do travel hundreds 
of km on occasion to find food or suitable breeding areas (Carretta et 
al., 2016). Based on likely foraging strategies, Grigg et al. (2009) 
reported seasonal shifts in harbor seal movements based on prey 
availability. In relationship to the entire California stock, harbor 
seals do not have a significant mainland California distribution south 
of Point Mugu.
    Harbor seals are relatively uncommon within San Diego Bay. 
Sightings in the Navy transect surveys of northern San Diego Bay 
through March 2012, and were limited to individuals outside of the ZOI, 
on the south side of Ballast Point (TDI 2012b; Jenkins 2012). However, 
Navy marine mammal monitoring for another project conducted 
intermittently at Pier 122 from 2010-2014 documented from zero to 4 
harbor seals near Pier 122 (within the ZOI) at various times, with the 
greatest number of sightings during April and May (Jenkins 2012; Bowman 
2014). An individual harbor seal was also frequently sighted near NMAWC 
during 2014 (McConchie 2014).

Northern Elephant Seal

    A complete population count of elephant seals is not possible 
because all age classes are not ashore simultaneously. The population 
is estimated to have grown at 3.8% annually since 1988 (Lowry et al., 
2014). Northern elephant seals breed and give birth in California 
(U.S.) and Baja California (Mexico), primarily on offshore islands. 
Populations of northern elephant seals in the U.S. and Mexico have 
recovered after being reduced to near extinction by hunting, undergoing 
a severe population bottleneck and loss of genetic diversity with the 
population reduced to only an estimated 10-30 individuals.
    Northern elephant seals occur in the southern California bight, and 
have the potential to occur in San Diego Bay (NAVFAC SW and POSD 2013), 
but the only recent documentation of occurrence was of a single 
distressed juvenile observed on the beach south and inshore of the Fuel 
Pier during the second year IHA. Given the continuing, long-term 
increase in the population of northern elephant seals (Lowry et al., 
2014), there is an increasing possibility of occurrence in the project 
area.

Marine Mammal Hearing

    Hearing is the most important sensory modality for marine mammals 
underwater, and exposure to anthropogenic sound can have deleterious 
effects. To appropriately assess the potential effects of exposure to 
sound, it is necessary to understand the frequency ranges marine 
mammals are able to hear. Current data indicate that not all marine 
mammal species have equal hearing capabilities (e.g., Richardson et 
al., 1995; Wartzok and Ketten 1999; Au and Hastings 2008). To reflect 
this, Southall et al. (2007) recommended that marine mammals be divided 
into functional hearing groups based on directly measured or estimated 
hearing ranges on the basis of available behavioral response data, 
audiograms derived using auditory evoked potential techniques, 
anatomical modeling, and other data. Note that no direct measurements 
of hearing ability have been successfully completed for mysticetes 
(i.e., low-frequency cetaceans). Subsequently, NMFS (2016) described 
generalized hearing ranges for these marine mammal hearing groups. 
Generalized hearing ranges were chosen based on the approximately 65 
decibel (dB) threshold from the normalized composite audiograms, with 
the exception for lower limits for low-frequency cetaceans where the 
lower bound was deemed to be biologically implausible and the lower 
bound from Southall et al. (2007) retained. The functional groups and 
the associated frequencies are indicated below (note that these 
frequency ranges correspond to the range for the composite group, with 
the entire range not necessarily reflecting the capabilities of every 
species within that group):
     Low-frequency cetaceans (mysticetes): Generalized hearing 
is estimated to occur between approximately 7 Hz and 35 kHz, with best 
hearing estimated to be from 100 Hz to 8 kHz;
     Mid-frequency cetaceans (larger toothed whales, beaked 
whales, and most delphinids): Generalized hearing is estimated to occur 
between approximately 150 Hz and 160 kHz, with best hearing from 10 to 
less than 100 kHz;
     High-frequency cetaceans (porpoises, river dolphins, and 
members of the genera Kogia and Cephalorhynchus; including two members 
of the genus Lagenorhynchus, on the basis of recent echolocation data 
and genetic data): Generalized hearing is estimated to occur between 
approximately 275 Hz and 160 kHz.
     Pinnipeds in water; Phocidae (true seals): Generalized 
hearing is estimated to occur between approximately 50 hertz (Hz) to 86 
kilohertz (kHz), with best hearing between 1-50 kHz;
     Pinnipeds in water; Otariidae (eared seals): Generalized 
hearing is estimated to occur between 60 Hz and 39 kHz, with best 
hearing between 2-48 kHz.
    The pinniped functional hearing group was modified from Southall et 
al. (2007) on the basis of data indicating that phocid species have 
consistently demonstrated an extended frequency range of hearing 
compared to otariids, especially in the higher frequency range 
(Hemil[auml] et al., 2006; Kastelein et al., 2009; Reichmuth and Holt 
2013).
    For more detail concerning these groups and associated frequency 
ranges, please see NMFS (2016) for a review of available information. 
Nine marine mammal species (six cetacean and three pinniped (1 otariid 
and 2 phocid species)) have the reasonable potential to co-occur with 
the proposed survey activities. Please refer to Table 2. Of the 
cetacean species that may be present, one is classified as low-
frequency cetaceans (i.e., all mysticete species), and five are 
classified as mid-frequency cetaceans (i.e., all delphinid and ziphiid 
species and the sperm whale).

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 by Incidental Harassment section 
later in this document includes a quantitative analysis of the number 
of individuals that are expected to be taken by this activity. The 
Negligible Impact Analysis and Determination section considers the 
content of this section, the Estimated Take by Incidental Harassment 
section, and the Proposed Mitigation section, to draw conclusions 
regarding the likely impacts of these activities on the reproductive 
success or survivorship of individuals and how those impacts on 
individuals are likely to impact marine mammal species or stocks.
    We provided discussion of the potential effects of the specified 
activity on marine mammals and their habitat in our Federal Register 
notices of proposed authorization associated with the first- and 
second-year IHAs (78 FR 30873; May 23, 2013 and 79 FR 53026; September 
5, 2014). The specified activity associated with this proposed IHA is 
substantially similar to those considered for the first- and second-
year IHAs and the potential effects of the specified activity are the 
same as those identified in those documents. Therefore, we do not 
reprint the

[[Page 36368]]

information here but refer the reader to those documents.
    In the aforementioned Federal Register notices, we also provided 
general background information on sound and marine mammal hearing and a 
description of sound sources and ambient sound and refer the reader to 
those documents. However, because certain terms are used frequently in 
this document, we provide brief definitions of relevant acoustic 
terminology below:
     Sound pressure level (SPL): Sound pressure is the force 
per unit area, usually expressed in microPascals ([mu]Pa), where one 
Pascal equals one Newton exerted over an area of one square meter. The 
SPL is expressed in dB as twenty times the logarithm to the base ten of 
the ratio between the pressure exerted by the sound to a referenced 
sound pressure. SPL is the quantity that is directly measured by a 
sound level meter. For underwater sound, SPL in dB is referenced to one 
microPascal (re 1 [mu]Pa), unless otherwise stated. For airborne sound, 
SPL in dB is referenced to 20 microPascals (re 20 [mu]Pa), unless 
otherwise stated.
     Frequency: Frequency is expressed in terms of 
oscillations, or cycles, per second. Cycles per second are commonly 
referred to as Hz. Typical human hearing ranges from 20 Hz to 20 kHz.
     Peak sound pressure: The instantaneous maximum of the 
absolute positive or negative pressure over the frequency range from 20 
Hz to 20 kHz and presented in dB.
     Root mean square (rms) SPL: For impact pile driving, 
overall dB rms levels are characterized by integrating sound for each 
waveform across ninety percent of the acoustic energy in each wave and 
averaging all waves in the pile driving event. This value is referred 
to as the rms 90 percent. With this method, the time averaging per 
pulse varies.
     Sound Exposure Level (SEL): A measure of energy, 
specifically the dB level of the time integral of the squared-
instantaneous sound pressure, normalized to a one second period. It is 
a useful metric for assessing cumulative exposure because it enables 
sounds of differing duration, to be compared in terms of total energy. 
The accumulated SEL (SELcum) is used to describe the SEL 
from multiple events (e.g., many pile strikes). This can be calculated 
directly as a logarithmic sum of the individual single-strike SELs for 
the pile strikes that were used to install the pile.
     Level Z weighted (unweighted), equivalent (LZeq): 
LZeq is a value recorded by the SLM that represents SEL SPL 
over a specified time period or interval. The LZeq is most typically 
referred to in one-second intervals or over an entire event.
     Level Z weighted (unweighted), fast (LZFmax): 
LZFmax is a value recorded by the SLM that represents the 
maximum rms value recorded for any 125 millisecond time frame during 
each individual recording.

Estimated Take

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

Acoustic Thresholds

    Using the best available science, NMFS has developed acoustic 
thresholds that identify the received level of underwater sound above 
which exposed marine mammals would be reasonably expected to be 
behaviorally harassed (equated to Level B harassment) or to incur PTS 
of some degree (equated to Level A harassment).
    Level B Harassment for non-explosive sources--Though significantly 
driven by received level, the onset of behavioral disturbance from 
anthropogenic noise exposure is also informed to varying degrees by 
other factors related to the source (e.g., frequency, predictability, 
duty cycle), the environment (e.g., bathymetry), and the receiving 
animals (hearing, motivation, experience, demography, behavioral 
context) and can be difficult to predict (Southall et al., 2007). Based 
on what the available science indicates and the practical need to use a 
threshold based on a factor that is both predictable and measurable for 
most activities, NMFS uses a generalized acoustic threshold based on 
received level to estimate the onset of behavioral harassment. NMFS 
predicts that marine mammals are likely to be behaviorally harassed in 
a manner we consider Level B harassment when exposed to underwater 
anthropogenic noise above received levels of 120 dB re 1 [mu]Pa (rms) 
for continuous (e.g. vibratory pile-driving, drilling) and above 160 dB 
re 1 [mu]Pa (rms) for non-explosive impulsive (e.g., impact pile 
driving) or intermittent (e.g., scientific sonar) sources.
    The Navy's proposed activity includes the use of continuous 
(vibratory pile driving, demolition) and impulsive (impact pile 
driving) sources, and therefore the 120 and 160 dB re 1 [mu]Pa (rms) 
are applicable.
    Level A harassment for non-explosive sources--NMFS's Technical 
Guidance for Assessing the Effects of Anthropogenic Sound on Marine 
Mammal Hearing (NOAA 2016) identifies dual criteria to assess auditory 
injury (Level A harassment) to five different marine mammal groups 
(based on hearing sensitivity) as a result of exposure to noise from 
two different types of sources (impulsive or non-impulsive). The Navy's 
construction project includes the use of impulsive (impact pile 
driving) and non-impulsive (vibratory pile driving) sources.
    These thresholds were developed by compiling and synthesizing the 
best available science and soliciting input multiple times from both 
the public and peer reviewers to inform the final product, and are 
provided in the table below. The references, analysis, and methodology 
used in the development of the thresholds are described in NMFS 2016 
Technical Guidance, which may be accessed at: http://

[[Page 36369]]

www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

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

Ensonified Area

    Here, we describe operational and environmental parameters of the 
activity that will feed into identifying the area ensonified above the 
acoustic thresholds.
    The intensity of pile driving or sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. For the installation of 
30-in steel piles and pile cutting activities, acoustic monitoring 
during the first and second IHA periods (NAVFAC 2015) resulted in 
empirical data that are directly applicable to the fifth IHA period in 
terms of the activities and the location, depth, sizes and types of 
piles.
    Table 4 identifies the sound source levels that are used in 
evaluating impact and vibratory pile driving and extraction in the 
current IHA application. Sound levels for the hydraulic pile cutter, 
diamond saw caisson cutting, and pile jetting were measured during the 
fourth IHA period (NAVFAC SW 2017). No acoustic data are available from 
the vibratory driving of 16-in concrete piles, so the data for 
vibratory installation of 30-in steel piles from the second IHA period 
are used as a conservative proxy (NAVFAC SW 2015). Finally, SPLs were 
measured for the impact driving of 16-in poly-concrete piles during the 
third IHA monitoring period (NAVFAC SW 2016a), and are used in this 
application for the same activities.

 Table 4--Underwater Sound Pressure Levels From Similar In Situ Monitored Construction Activities From Previous
                                                      Years
----------------------------------------------------------------------------------------------------------------
                                                                                         Measured sound pressure
                                                                                          levels (rms) at 10 m
      Project and location         Pile size and type        Method        Water depth      (dB re 1 [mu]Pa)
                                                                                       -------------------------
                                                                                          Mean \1\     Max \2\
----------------------------------------------------------------------------------------------------------------
NBPL Fuel Pier, San Diego, CA...  13 to 24-in          Hydraulic pile      9 m (30 ft)          145        165.3
                                   concrete.            cutting.
NBPL Fuel Pier, San Diego, CA...  66- and 84-in steel  Diamond saw         9 m (30 ft)          149        155.6
                                   caisson.             cutting.
NBPL Fuel Pier, San Diego, CA...  24-in concrete.....  Jetting...........  9 m (30 ft)          155        159.9
NBPL Fuel Pier, San Diego, CA...  30-in Steel Pipe...  Vibratory.........  9 m (30 ft)        162.5    \3\ 162.5
NBPL Fuel Pier, San Diego, CA...  16-in Poly-Concrete  Impact............  9 m (30 ft)        188.9      \4\ 195
----------------------------------------------------------------------------------------------------------------
\1\ Mean source levels used from data from previous monitoring reports (NAVFAC SW 2015, 2016a, 2017). Mean
  source levels were used to calculate Level B ZOIs.
\2\ Maximum source levels used from data from previous monitoring reports (NAVFAC SW 2015, 2016a, 2017). Max
  source levels were used to calculate Level A ZOIs. Maximum source levels used were proposed by the Navy.
\3\ Mean source levels for 30-in steel pipe piles were used as a proxy to calculate ZOIs for vibratory driving
  of 16-in concrete guide piles (NAVFAC SW 2015).
\4\ The maximum source level is included for reference only. The distance to the Level B ZOI is based on in situ
  data collected for 16-in poly-concrete piles and was documented in NAVFAC SW (2016a).

    Scarce data exists on airborne and underwater noise levels 
associated with vibratory hammer extraction. However, it can reasonably 
be assumed that vibratory extraction emits SPLs that are no higher than 
SPLs caused by vibratory hammering of the same materials, and results 
in lower SPLs than caused by impact hammering comparable piles. For 
this application, the same value (162.5 dB re 1[mu]Pa) that was 
obtained for vibratory hammering of the 30-in steel piles at the Fuel 
Pier (NAVFAC SW 2015) is used for the vibratory hammering of 16-in 
round concrete piles at NMAWC. None of the peak SPLs for the various 
sound sources reach the injury thresholds identified in the new NMFS 
(2016) Technical Guidance; therefore, injury from peak sound levels is 
not considered further.
    Table 6 provides the calculated areas of Level A and Level B ZOIs 
associated with the impulsive and continuous sounds that are 
anticipated during the fifth-year IHA period. Table 5 provides the data 
that were used to calculate the distances to the Level A and B ZOIs 
presented in Table 6. It should be noted that the ZOI for Level A 
harassment would be closely monitored and subject to shutdowns if a 
marine mammal enters the area. The ZOI areas and maximum distances for 
the activities at the fuel pier and NMAWC are shown in Figures 6-1 and 
6-2, respectively of the Navy's application. The figures reflect the 
conventional assumption that the natural or manmade shoreline acts as a 
barrier to underwater sound. It is generally accepted practice to model 
underwater sound propagation from pile driving as continuing in a 
straight line past a shoreline projection such as Ballast Point (Dahl 
2012). Similarly, it is reasonable to assume that project sound would 
not propagate east of Zuniga Jetty (Dahl 2012).

[[Page 36370]]

    All of the ZOIs for potential Level A acoustic harassment (Table 6) 
would be buffered and encompassed by a larger shutdown zone. For 
example, the ZOIs for potential Level A acoustic harassment to 
pinnipeds from impact pile driving (Table 6) would be contained within 
a 60 m (196 ft) shutdown zone. For impact pile driving at NMAWC, two 
methods identified in NMFS (2016) were evaluated to determine the most 
conservative distances to the Level A ZOIs using: (1) rms SPL source 
levels; and (2) single strike equivalent SEL. The calculations showed 
that the first method was the most conservative and this method was 
subsequently used to determine the distances to the Level A ZOIs (Table 
5). In all Level A ZOI calculations, the default values for the 
weighting factor adjustment and practical spreading for propagation 
loss were used (see Appendix A of the Navy's application).

                                                Table 5--Data Used To Calculate Distances to Level B ZOIs
--------------------------------------------------------------------------------------------------------------------------------------------------------
              Activity                 Impact pile driving   Vibratory pile driving       Pile jetting         Caisson cutting         Pile clipping
--------------------------------------------------------------------------------------------------------------------------------------------------------
References for Source Level and      Year 3 report #1        Year 2 report (NAVFAC   Year 4 report (NAVFAC  Year 3 report #1       Year 4 report (NAVFAC
 Duration.                            (NAVFAC SW 2016a).      SW 2015).               SW 2017).              (NAVFAC SW 2016a).     SW 2017).
Size & Type of Piles used for        16-in poly-concrete     30-in steel piles.....  24x30-in concrete      84-in caissons.......  24-in concrete piles.
 Source Data.                         piles.                                          piles.
Source Level (rms SPL).............  188.9.................  162.5.................  159.9................  155.6................  165.3.
Distance to Level B ZOI (m)........  270...................  1,848.................  1,165................  631..................  2,511.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    The Level B ZOIs and distances are based on the validated SPLs 
directly measured during the IHA monitoring (NAVFAC SW 2014-2017), as 
available. For example, the distance to the Level B ZOI for impact 
driving of 16-in poly-concrete piles was 270 m (886 ft) during Year 3 
monitoring (NAVFAC SW 2016a). In cases where monitoring data are not 
available to empirically measure the extent of the Level B ZOI 
(activities at NMAWC), ``practical spreading loss'' from the source at 
10 m has been assumed (15 log[distance/10]) and used to calculate the 
maximum extent of the ZOI based on the applicable threshold. Computed 
distances to the threshold for acoustic disturbance from non-impulsive 
sources are based on the distances at which the project sound source 
declines to ambient. Because the mean ambient sound levels in San Diego 
Bay range from approximately 128 to 130 dB rms (NAVFAC SW 2015), the 
120 dB acoustic threshold for the Level B ZOIs are based on an 
approximate value between 128 and 129 dB. The distances for all 
activities producing sound at NMAWC will be verified via hydrophone 
during project activities.

                                     Table 6--Calculated Maximum Areas of ZOIs and Distances to Relevant Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                   Measured/calculated distances to thresholds (m) and areas of ZOIs  (m\2\ or km\2\)
                              --------------------------------------------------------------------------------------------------------------------------
                                                                        Underwater                                                    Airborne
           Activity           --------------------------------------------------------------------------------------------------------------------------
                                                    Level A \1\ \2\ \3\                                Level B \4\                     Level B
                              --------------------------------------------------------------------------------------------------------------------------
                                     LF              MF              PW              OW           160 dB       120 dB \5\     100 dB \6\     90 dB \6\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Old Fuel Pier and Temporary Mooring Dolphin Demolition
--------------------------------------------------------------------------------------------------------------------------------------------------------
66-inch and 84-inch caissons   3.6 m           0.3 m           2.2 m           0.2m           N/A            631 m                       N/A
 (Diamond saw cutting).        41 m\2\         <1 m\2\         15 m\2\         <1 m\2\                       0.7157 km\2\
Concrete piles (Pile           1.2 m           0.1 m           0.7 m           0.0 m          N/A            2,511 m
 clipping).                    4 m\2\          <1 m\2\         < 1 m\2\        0 m\2\                        4.4512 km\2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            NMAWC Construction and Demolition
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch concrete piles         8.3 m           0.7 m           5.1 m           0.4 m          N/A            1,848 m        42 m           149 m
 (Vibratory extraction/        216 m\2\        <1 m\2\         82 m\2\         <1 m\2\                       2.4473 km\2\   5,503 m\2\     69,646 m\2\
 driving) \8\.
16-inch concrete piles         63.4 m          2.3 m           33.9 m          2.5 m          270 m          N/A
 (Impact driving) \9\.         0.0126 km\2\    17 m\2\         3,610 m\2\      20 m\2\        0.1408 km\2\
                                                                                                                           -----------------------------
16-inch concrete piles         3.9 m           0.3 m           2.4 m           0.2 m          N/A            1,165m                      N/A
 (Jetting pile extraction).    47.8 m\2\       <1 m\2\         18 m\2\         <1 m\2\                       1.4268 km\2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ If measured value thresholds are less than 10 m (33 ft), a minimum monitoring distance of 10 m (33 ft) would be implemented.
\2\ Based on measured mean source levels. The relevant data have been included in Appendix A of the Navy's application, which provides information from
  previous years' data collected as part of the Fuel Pier Project (NAVFAC SW 2015, 2016a, 2017).
\3\ LF = Low-frequency cetaceans; MF = Mid-frequency cetaceans; PW = Phocid pinnipeds; OW = Otariid pinnipeds. The high-frequency cetacean hearing group
  (HF) is omitted, because no species in the hearing group occur in, or around, the Project area.
\4\ Based on measured maximum source levels, unless otherwise stated. The relevant data have been included in Appendix A, which provides information
  from previous years' data collected as part of the Fuel Pier Project (NAVFAC SW 2015, 2016a, 2017).
\5\ Average ambient sound levels in San Diego Bay are approximately 128 to 130 dB rms (NAVFAC SW 2015), and all 120 dB Level B ZOIs are based on an
  approximate value between 128 and 129, which represents ambient levels in the Bay.
\6\ Airborne ZOIs based on conservative representative data (collected during 30-inch vibratory pile driving from IHA #4). Airborne noise levels did not
  exceed thresholds during IHA #4 monitoring of demolition activities.
\7\ Plasma torch noise levels are not expected to exceed underwater or airborne regulatory thresholds.
\8\ Based on conservative representative source levels of 162.5 dB rms (30-inch steel vibratory pile driving, NAVFAC SW 2015).


[[Page 36371]]

Airborne Sound

    Although sea lions are known to haul-out regularly on man-made 
objects in the vicinity of the project site (see Figure 4-1 of the 
Navy's application), and harbor seals are occasionally observed hauled 
out on rocks along the shoreline in the vicinity of the project site, 
none of these are within the ZOIs for airborne sound, and we believe 
that incidents of take resulting solely from airborne sound are 
unlikely. The zones for sea lions are within the minimum shutdown zone 
defined for underwater sound and, although the zones for harbor seals 
are larger, they have not been observed to haul out as readily on man-
made structure in the immediate vicinity of the project site. There is 
a possibility that an animal could surface in-water, but with head out, 
within one of the defined zones and thereby be exposed to levels of 
airborne sound that we associate with harassment, but any such 
occurrence would likely be accounted for in our estimation of 
incidental take from underwater sound.
    We generally recognize that pinnipeds occurring within an estimated 
airborne harassment zone, whether in the water or hauled out, could be 
exposed to airborne sound that may result in behavioral harassment. 
However, any animal exposed to airborne sound above the behavioral 
harassment threshold is likely to also be exposed to underwater sound 
above relevant thresholds (which are typically in all cases larger 
zones than those associated with airborne sound). Thus, the behavioral 
harassment of these animals is already accounted for in these estimates 
of potential take. Multiple incidents of exposure to sound above NMFS' 
thresholds for behavioral harassment are not believed to result in 
increased behavioral disturbance, in either nature or intensity of 
disturbance reaction. Therefore, we do not believe that authorization 
of incidental take resulting from airborne sound for pinnipeds is 
warranted, and airborne sound is not discussed further here. Distances 
associated with airborne sound and shown in Table 5 are for reference 
only.
    When NMFS Technical Guidance (2016) was published, in recognition 
of the fact that ensonified area/volume could be more technically 
challenging to predict because of the duration component in the new 
thresholds, we developed a User Spreadsheet that includes tools to help 
predict a simple isopleth that can be used in conjunction with marine 
mammal density or occurrence to help predict takes. We note that 
because of some of the assumptions included in the methods used for 
these tools, we anticipate that isopleths produced are typically going 
to be overestimates of some degree, which will result in some degree of 
overestimate of Level A take. However, these tools offer the best way 
to predict appropriate isopleths when more sophisticated 3D modeling 
methods are not available, and NMFS continues to develop ways to 
quantitatively refine these tools, and will qualitatively address the 
output where appropriate. For stationary sources such as vibratory pile 
driving, NMFS User Spreadsheet predicts the closest distance at which, 
if a marine mammal remained at that distance the whole duration of the 
activity, it would not incur PTS. Inputs used in the User Spreadsheet, 
and the resulting isopleths are reported below.

                                                         Table 7--Level A User Spreadsheet Input
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                       Impact pile driving   Vibratory pile driving     Caisson cutting         Pile clipping           Pile jetting
--------------------------------------------------------------------------------------------------------------------------------------------------------
References for Source Level and      Year 3 report #1        Year 2 report (NAVFAC   Year 3 report #1       Year 4 report (NAVFAC  Year 4 report (NAVFAC
 Duration.                            (NAVFAC SW 2016a).      SW 2015).               (NAVFAC SW 2016a).     SW 2017).              SW 2017).
Spreadsheet Tab Used...............  (E.1) Impact pile       (A.) Non-Impulse Stat-  (A.) Non-Impulse Stat- (A.) Non-Impulse Stat- (A.) Non-Impulse Stat-
                                      driving.                Cont.                   Cont.                  Cont.                  Cont.
Source Level (Single Strike/shot     188.9.................  162.5.................  149..................  145..................  155.
 SEL).
Weighting Factor Adjustment (kHz)..  2.....................  2.5...................  2.5..................  2.5..................  2.5.
(a) Activity Duration (h) within 24- 0.71..................  0.95..................  6....................  2.82.................  1.74.
 h period.
Propagation (xLogR)................  15....................  15....................  15...................  15...................  15.
Distance of source level             10....................  10....................  10...................  10...................  10.
 measurement (m).
Pulse duration (sec) \1\...........  0.03..................  n/a...................  n/a..................  n/a..................  n/a.
Number of strikes in 1 h...........  193...................  n/a...................  n/a..................  n/a..................  n/a.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Pulse duration was measured in previous construction years and the average pulse duration was 0.03 at 10 m (NAVFAC SW 2016a).

Marine Mammal Occurrence

    In this section we provide the information about the presence, 
density, or group dynamics of marine mammals that will inform the take 
calculations.
    For all species, the best scientific information available was 
considered for use in the marine mammal take assessment calculations. 
Although various regional offshore surveys for marine mammals have been 
conducted, it is unlikely that these data would be representative of 
the species or numbers that may be encountered in San Diego Bay. 
However, the Navy has conducted a large number of ongoing site-specific 
marine mammal surveys during appropriate seasons (e.g., Merkel and 
Associates 2008; Johnson 2010, 2011; Lerma 2012, 2014). Whereas 
analyses for the first-year IHA relied on surveys conducted from 2007-
12, continuing surveys by the Navy have generally indicated increasing 
abundance of all species and the second-year IHA relied on 2012-14 
survey data. In addition, the Navy has developed estimates of marine 
mammal densities in waters associated with training and testing areas 
(including Hawaii-Southern California) for the Navy Marine Species 
Density Database (NMSDD). A technical report (Hanser et al., 2015) 
describes methodologies and available information used to derive these 
densities, which are based upon the best available information, except 
where specific local abundance information is available and applicable 
to a specific action area. The document is publicly available online 
at: nwtteis.com/DocumentsandReferences/NWTTDocuments/SupportingTechnicalDocuments.aspx (accessed July 13, 2017).
    Year 2 project monitoring showed even greater abundance of certain 
species, and we consider all of these data in order to provide the most 
up-to-date estimates for marine mammal abundances during the period of 
this proposed IHA. Although Years 3 and 4 project monitoring showed 
declines in marine mammal abundance in the vicinity of the project, we 
retain prior density estimates as a conservative measure for estimating 
exposure.

[[Page 36372]]

Density information is shown in Table 9. These data are from dedicated 
line-transect surveys, required project marine mammal monitoring, 
opportunistic observations for more rarely observed species (see 
Figures 3-1 through 3-5 of the Navy's application), or the NMSDD.

Take Calculation and Estimation

    Here we describe how the information provided above is brought 
together to produce a quantitative take estimate.
    The following assumptions are made when estimating potential 
incidences of take:
     All marine mammal individuals potentially available are 
assumed to be present within the relevant area, and thus incidentally 
taken;
     An individual can only be taken once during a 24-h period;
     The assumed ZOIs and days of activity are as shown in 
Table 5; and,
     Exposures to sound levels at or above the relevant 
thresholds equate to take, as defined by the MMPA.
    In this case, the estimation of marine mammal takes uses the 
following calculation:

Exposure estimate = n * ZOI * days of total activity


Where:
n = density estimate used for each species/season.
ZOI = sound threshold ZOI area; the area encompassed by all 
locations where the SPLs equal or exceed the threshold being 
evaluated.

    The ZOI impact area is estimated using the relevant distances in 
Table 5, assuming that sound radiates from a central point in the water 
column slightly offshore of the existing pier and taking into 
consideration the possible affected area due to topographical 
constraints of the action area (i.e., radial distances to thresholds 
are not always reached).

        Table 8--Areas of Acoustic Influence and Days of Activity
------------------------------------------------------------------------
                Activity                  Number of days    ZOI (km\2\)
------------------------------------------------------------------------
66-inch and 84-inch caissons (Diamond                 50          0.7157
 saw cutting)...........................
Concrete piles (Pile clipping)..........             100          4.4512
16-inch concrete piles (Vibratory                     25          2.4473
 extraction/driving) \1\................
16-inch concrete piles (Jetting pile                  15          1.4268
 extraction)............................
------------------------------------------------------------------------
\1\ We assume that impact driving of 16-in concrete piles would always
  occur on the same day as vibratory driving of the same piles.
  Therefore, the impact driving ZOI (0.1408 km\2\) would always be
  subsumed by the vibratory driving ZOI.

    There are a number of reasons why estimates of potential incidents 
of take may be conservative, assuming that available density and 
estimated ZOI areas are accurate. We assume, in the absence of 
information supporting a more refined conclusion, that the output of 
the calculation represents the number of individuals that may be taken 
by the specified activity. In fact, in the context of stationary 
activities such as pile driving and in areas where resident animals may 
be present, this number more realistically represents the number of 
incidents of take that may accrue to a smaller number of individuals. 
While pile driving can occur any day throughout the period of validity, 
and the analysis is conducted on a per day basis, only a fraction of 
that time (typically a matter of hours on any given day) is actually 
spent pile driving. The potential effectiveness of mitigation measures 
in reducing the number of takes is typically not quantified in the take 
estimation process. For these reasons, these take estimates may be 
conservative. See Table 9 for total estimated incidents of take.

California Sea Lion

    During the second IHA period, an average of 90.35 California sea 
lions were seen per day within the maximum ZOI for pile driving, an 
area of 5.6752 km\2\ extending 3,000 m from the Fuel Pier. This equates 
to a density of 15.9201/km\2\. This density is used to estimate numbers 
of takes within the different ZOIs. NMFS estimates 8,971 Level B takes 
for this species. The maximum extents of the potential acoustic Level A 
ZOIs for cumulative exposure from all of the activities are much less 
than 10 m from the source, and therefore the 60-m shutdown zone will 
reduce the chance for Level A take. As a result, no Level A take of 
California sea lions is anticipated nor proposed to be authorized.

Harbor Seal

    Sightings of harbor seals averaged 2.83 individuals per day during 
the period of the second IHA (NAVFAC SW 2015), a density of 0.4987/
km\2\ within the maximum ZOI for pile driving. This density is used to 
estimate numbers of takes within the different ZOIs. NMFS estimates 281 
Level B takes for this species. The maximum extent of the potential 
acoustic Level A ZOI for cumulative exposure from impact pile driving 
extends 34 m from the source; for all other activities, the Level A 
ZOIs are much less than 10 m from the source, therefore a 60-m shutdown 
zone will be in place to avoid Level A takes to harbor seals. Level A 
takes are not anticipated nor proposed for authorization.

Northern Elephant Seal

    Only a single individual elephant seal was sighted during the 
second IHA period (NAVFAC SW 2015), but with increasing numbers 
(Carretta et al., 2016), they are considered a reasonable possibility 
to occur more frequently during the fifth IHA period. The regional 
density estimate of 0.0760/km\2\ (Navy 2017) is assumed for the project 
area. This density is used to estimate numbers of takes within the 
different ZOIs. NMFS estimates 43 Level B takes for this species. 
Potential takes would likely involve single individuals that are on the 
shoreline or structures at the identified location, or swimming in the 
vicinity, most likely near the mouth of the bay. The maximum extent of 
the potential acoustic Level A ZOI for cumulative exposure from impact 
pile driving extends 34 m from the source; for all other activities, 
the Level A ZOIs are much less than 10 m from the source, therefore a 
shutdown will be in place to avoid Level A takes to harbor seals. Level 
A takes are not anticipated nor proposed for authorization.

Bottlenose Dolphin

    Coastal bottlenose dolphins can occur at any time of year in 
northern San Diego Bay. Numbers sighted have been highly variable but 
have increased in recent years (NAVFAC SW 2014, 2015). During the 
second IHA period, an average of 7.09 individuals was seen per day, a 
density of 1.2493/km\2\. This density is used to estimate numbers of 
takes within the different ZOIs. NMFS estimates 704 Level B takes for 
this species. The maximum extents of the potential acoustic Level A 
ZOIs for cumulative exposure from all of the activities are much less 
than 10 m from

[[Page 36373]]

the source, and therefore the minimum 10 m shutdown will reduce the 
chance for Level A take. As a result, no Level A take of bottlenose 
dolphins is anticipated nor proposed to be authorized.

Common Dolphin

    An average of 8.67 common dolphins was seen per day, a density of 
1.5277/km\2\ within the maximum ZOI, during the second IHA period 
(NAVFAC SW 2015). This density is considerably higher than the regional 
density estimate for long-beaked common dolphins--the species most 
likely to occur (Navy 2017), but is reasonable for the project area 
given the group sizes observed for these species. Barlow (2010) 
reported average group sizes in southern California of 122 for short-
beaked common dolphins and 195 for long-beaked common dolphins, and 
during the second IHA period, groups of approximately 170 and 300 
individuals entered the project area on different occasions (NAVFAC SW 
2015). Considering the possibility for one or more large groups of 
common dolphins to enter San Diego Bay during in-water activities and 
the fact that the Level B ZOIs will extend completely across the bay 
during pile driving, the density estimate is considered appropriate. A 
density of 1.5277/km\2\ is used to estimate numbers of takes within the 
different ZOIs. NMFS estimates 861 Level B takes for this species. The 
maximum extents of the potential acoustic Level A ZOIs for cumulative 
exposure from all of the activities are much less than 10 m from the 
source, and therefore the shutdown will reduce the chance for Level A 
take. As a result, no Level A take of bottlenose dolphins is 
anticipated nor proposed to be authorized.

Pacific White-Sided Dolphin

    Pacific white-sided dolphins are more commonly seen offshore, but 
were documented in the project area on several occasions during the 
second IHA period. An average of 0.28 individuals per day was seen 
during the second IHA period (NAVFAC SW 2015), a density of 0.0493/
km\2\ within the maximum ZOI. This density is used to estimate numbers 
of takes within the different ZOIs. NMFS estimates 28 Level B takes for 
this species. The maximum extents of the potential acoustic Level A 
ZOIs for cumulative exposure from all of the activities are much less 
than 10 m from the source, and therefore the shutdown will reduce the 
chance for Level A take. As a result, no Level A take of bottlenose 
dolphins is anticipated nor proposed to be authorized.

Risso's Dolphin

    While there have been no sightings of Risso's dolphin within the 
project area, the species is considered a reasonable possibility for 
the fifth IHA period given recent El Ni[ntilde]o conditions (Shane 
1995) and its abundance in Southern California coastal waters 
(Jefferson et al. 2014). The upper limit of the regional density 
estimate, 0.2029/km\2\ (Navy 2017), is used to estimate numbers of 
takes within the different ZOIs. NMFS estimates 114 Level B takes for 
this species. The maximum extents of the potential acoustic Level A 
ZOIs for cumulative exposure from all of the activities are much less 
than 10 m from the source, and therefore the shutdown will reduce the 
chance for Level A take. As a result, no Level A take of bottlenose 
dolphins is anticipated nor proposed to be authorized.

Gray Whale

    Gray whale occurrence within northern San Diego Bay is sporadic and 
would likely consist of one-few individuals that venture close to, or 
enter the bay for a brief period, and then continue on their migration. 
A density estimate based on the rare sightings of gray whales near the 
mouth of the bay during the second IHA period (NAVFAC SW 2015), would 
be less than 0.01/km\2\, which is slightly less than the regional 
density estimate of 0.0179/km\2\ in southern California waters during 
winter-spring (Navy 2017). The regional density estimate is applied 
here as a reasonable estimate given the possibility of animals moving 
closer to shore and entering the mouth of the bay during the fifth IHA 
period. This density is used to estimate numbers of takes within the 
different ZOIs. NMFS estimates 10 Level B takes for this species. The 
maximum extent of the potential acoustic Level A ZOI for cumulative 
exposure from impact pile driving extends 63 m from the source; for all 
other activities, the Level A ZOIs are much less than 10 m from the 
source. Gray whales are not expected to occur that close to the source; 
however, the Navy has proposed a minimum of 10 m (100 m for impact 
driving) shutdown will be in place to avoid Level A takes to gray 
whales. Level A takes are not anticipated nor proposed for 
authorization.

                                                  Table 9--Calculations for Incidental Take Estimation
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                             Vibratory
                                                            Diamond saw                     extraction/    Jetting pile                   Total proposed
                 Species                      Density     cutting of 66-   Pile clipping  driving of 16-   extraction of   Total Level B    authorized
                                                           inch and 84-   concrete piles   inch concrete  16 in concrete      takes *       takes (% of
                                                           inch caissons                       piles           piles                       total stock)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion.....................         15.9201             570            7086             974             341           8,971           3.023
Harbor seal.............................          0.4987              18             222              31              11             281           0.907
Northern elephant seal..................           0.076               3              34               5               2              43           0.024
Bottlenose dolphin......................          1.2493              45             556              76              27             704         \2\ 155
Common dolphin..........................          1.5277              55             680              93              33             861  \3\ 0.088; \4\
                                                                                                                                                    0.85
Pacific white-sided dolphin.............          0.0493               2              22               3               1              28           0.104
Risso's dolphin.........................          0.2027               7              90              12               4             114           1.799
Gray whale..............................          0.0179               1               8               1               0              10           0.048
--------------------------------------------------------------------------------------------------------------------------------------------------------
* Due to rounding of takes to the nearest whole number of animals, (which occurs at the very end, not per activity), totals may not always equal the sum
  of the takes from individual activities.
\1\ We assume that impact driving of steel piles would occur on the same day as vibratory driving of the same piles and that the zone for vibratory
  driving would always subsume the zone for impact driving. Therefore, separate estimates are not provided for impact driving of steel piles.
\2\ The proposed numbers of authorized take for bottlenose dolphins are higher relative to the total stock abundance estimate and would not represent
  small numbers if a significant portion of the take was for a new individual. However, these numbers represent the estimated incidents of take, not the
  number of individuals taken. That is, it is likely that a relatively small subset of California coastal bottlenose dolphins would be incidentally
  harassed by project activities.
\3\ SB = short-beaked common dolphin.
\4\ LB = long-beaked common dolphin.


[[Page 36374]]

Proposed Mitigation

    In order to issue an IHA under section 101(a)(5)(D) of the MMPA, 
NMFS must set forth the permissible methods of taking pursuant to such 
activity, and other means of effecting the least practicable impact on 
such species or stock and its habitat, paying particular attention to 
rookeries, mating grounds, and areas of similar significance, and on 
the availability of such species or stock for taking for certain 
subsistence uses (latter not applicable for this action). NMFS 
regulations require applicants for incidental take authorizations to 
include information about the availability and feasibility (economic 
and technological) of equipment, methods, and manner of conducting such 
activity or other means of effecting the least practicable adverse 
impact upon the affected species or stocks and their habitat (50 CFR 
216.104(a)(11)).
    In evaluating how mitigation may or may not be appropriate to 
ensure the least practicable adverse impact on species or stocks and 
their habitat, as well as subsistence uses where applicable, we 
carefully consider two primary factors:
    (1) The manner in which, and the degree to which, the successful 
implementation of the measure(s) is expected to reduce impacts to 
marine mammals, marine mammal species or stocks, and their habitat. 
This considers the nature of the potential adverse impact being 
mitigated (likelihood, scope, range). It further considers the 
likelihood that the measure will be effective if implemented 
(probability of accomplishing the mitigating result if implemented as 
planned) the likelihood of effective implementation (probability 
implemented as planned). And;
    (2) The practicability of the measures for applicant 
implementation, which may consider such things as cost, impact on 
operations, and, in the case of a military readiness activity, 
personnel safety, practicality of implementation, and impact on the 
effectiveness of the military readiness activity.
    The mitigation strategies described below largely follow those 
required and successfully implemented under the first four IHAs 
associated with this project. For this proposed IHA, data from acoustic 
monitoring conducted during the first four years of work was used to 
estimate zones of influence (ZOIs; see Estimated Take by Incidental 
Harassment); these values were used to develop mitigation measures for 
pile driving activities at NBPL. The ZOIs effectively represent the 
mitigation zone that would be established around each pile to minimize 
Level A harassment to marine mammals, while providing estimates of the 
areas within which Level B harassment might occur. In addition, the 
Navy has defined buffers to the estimated Level A harassment zones to 
further reduce the potential for Level A harassment. In addition to the 
measures described later in this section, the Navy would conduct 
briefings between construction supervisors and crews, marine mammal 
monitoring team, acoustic monitoring team, and Navy staff prior to the 
start of all pile driving activity, and when new personnel join the 
work, in order to explain responsibilities, communication procedures, 
marine mammal monitoring protocol, and operational procedures.

Monitoring and Shutdown for Pile Driving

    The following measures would apply to the Navy's mitigation through 
shutdown and disturbance zones:
    Shutdown Zone--For all pile driving and removal activities, the 
Navy will establish a shutdown zone intended to contain the area in 
which SPLs equal or exceed the calculated Level A zones (refer to 
table). The purpose of a shutdown zone is to define an area within 
which shutdown of activity would occur upon sighting of a marine mammal 
(or in anticipation of an animal entering the defined area), thus 
preventing injury of marine mammals (serious injury or death are 
unlikely outcomes even in the absence of mitigation measures). 
Estimated radial distances to the relevant thresholds are shown in 
Table 5. For certain activities, the shutdown zone would not exist 
because source levels indicate that the radial distance to the 
threshold would be less than 10 m. However, a minimum shutdown zone of 
10 m will be established during all pile driving and removal 
activities, regardless of the estimated zone. In addition the Navy 
proposes to effect a buffered shutdown zone that is intended to 
significantly reduce the potential for Level A harassment given that, 
in particular, California sea lions are quite abundant in the project 
area and bottlenose dolphins may surface unpredictably and move 
erratically in an area with a large amount of construction equipment. 
These buffers are approximately double the distance to the Level A ZOI. 
These zones are also shown in Table 10. These precautionary measures 
are intended to prevent the already unlikely possibility of physical 
interaction with construction equipment and to establish a 
precautionary minimum zone with regard to acoustic effects.

                Table 10--Shutdown Zones for Level A ZOIs and Monitoring Zones for Level B Zones
----------------------------------------------------------------------------------------------------------------
                                                  Monitored distances to thresholds (meters [feet])
                                   -----------------------------------------------------------------------------
                                                                     Underwater
             Activity              -----------------------------------------------------------------------------
                                                    Level A (shutdown)                           Level B
                                   -----------------------------------------------------------------------------
                                       LF \1\       MF \1\       PW \1\       OW \1\       160 dB     120 dB \2\
----------------------------------------------------------------------------------------------------------------
                             Old Fuel Pier and Temporary Mooring Dolphin Demolition
----------------------------------------------------------------------------------------------------------------
66-inch and 84-inch caissons                                                                    N/A          631
 (Diamond saw cutting)............                          10
                                   ----------------------------------------------------
Concrete piles (Pile clipping)....                          10                                  N/A        2,511
----------------------------------------------------------------------------------------------------------------
                                        NMAWC Construction and Demolition
----------------------------------------------------------------------------------------------------------------
16-inch concrete piles (Vibratory
 extraction/driving)..............           20 \4\
                                               10                     N/A        1,848
                                   ----------------------------------------------------
16-inch concrete piles (Impact
 driving).........................           100 \5\
                                             60 \6\                 857.7          N/A
                                   ----------------------------------------------------
16-inch concrete piles (Jetting                                                                 N/A        1,165
 pile extraction).................                          10
                                   -----------------------------------------------------------------------------

[[Page 36375]]

 
16-inch concrete piles (Pile dead-
 pull)............................                          10
                                               N/A
----------------------------------------------------------------------------------------------------------------
\1\ LF = Low-frequency cetaceans; MF = Mid-frequency cetaceans; PW = Phocid pinnipeds; OW = Otariid pinnipeds.
  The high-frequency cetacean hearing group (HF) is omitted, because no species in the hearing group occur in,
  or around, Project area.
\2\ Mean ambient sound levels in San Diego Bay are approximately 128 dB rms (NAVFAC SW 2015), and all 120 dB
  Level B ZOIs are based on the ambient value. The distances for all activities producing sound at NMAWC will be
  verified via hydrophone during project activities.
\3\ Airborne noise levels did not exceed regulatory thresholds during previous IHAs. No airborne monitoring will
  take place for diamond saw cutting of caissons, plasma torch cutting of temporary mooring dolphin 30-inch
  steel piles, jetting or dead-pull extraction of concrete piles.
\4\ Includes buffer of calculated Level A threshold out to 20 m (65.6 ft).
\5\ Includes buffer of calculated Level A threshold out to 100 m (328 ft).
\6\ Includes buffer of calculated Level A threshold out to 60 m (328 ft).

    Disturbance Zone--Disturbance zones are the areas in which SPLs 
equal or exceed 160 and 120 dB rms (for impulse and continuous sound, 
respectively). Disturbance zones provide utility for monitoring 
conducted for mitigation purposes (i.e., shutdown zone monitoring) by 
establishing monitoring protocols for areas adjacent to the shutdown 
zones. Monitoring of disturbance zones enables observers to be aware of 
and communicate the presence of marine mammals in the project area but 
outside the shutdown zone and thus prepare for potential shutdowns of 
activity. However, the primary purpose of disturbance zone monitoring 
is for documenting incidents of Level B harassment; disturbance zone 
monitoring is discussed in greater detail later (see Proposed 
Monitoring and Reporting). Nominal radial distances for disturbance 
zones are shown in Table 10.
    In order to document observed incidents of harassment, monitors 
record all marine mammal observations, regardless of location. The 
observer's location, as well as the location of the pile being driven, 
is known from a GPS. The location of the animal is estimated as a 
distance from the observer, which is then compared to the location from 
the pile. If acoustic monitoring is being conducted for that pile, a 
received SPL may be estimated, or the received level may be estimated 
on the basis of past or subsequent acoustic monitoring. It may then be 
determined whether the animal was exposed to sound levels constituting 
incidental harassment in post-processing of observational and acoustic 
data, and a precise accounting of observed incidences of harassment 
created. Therefore, although the predicted distances to behavioral 
harassment thresholds are useful for estimating incidental harassment 
for purposes of authorizing levels of incidental take, actual take may 
be determined in part through the use of empirical data.
    Acoustic measurements will continue during the fifth year of 
project activity and zones would be adjusted as indicated by empirical 
data. Please see the Navy's Acoustic and Marine Species Monitoring Plan 
(Monitoring Plan; available at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm) for full details.
    Monitoring Protocols--Monitoring would be conducted before, during, 
and after pile driving activities. In addition, observers shall record 
all incidents of marine mammal occurrence, regardless of distance from 
activity, and shall document any behavioral reactions in concert with 
distance from piles being driven. Observations made outside the 
shutdown zone will not result in shutdown; that pile segment would be 
completed without cessation, unless the animal approaches or enters the 
shutdown zone, at which point all pile driving activities would be 
halted. Monitoring will take place from fifteen minutes prior to 
initiation through thirty minutes post-completion of pile driving 
activities. Pile driving activities include the time to remove a single 
pile or series of piles, as long as the time elapsed between uses of 
the pile driving equipment is no more than thirty minutes. Please see 
the Monitoring Plan for full details of the monitoring protocols.
    The following additional measures apply to visual monitoring:
    (1) Monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable (as defined in the 
Monitoring Plan) to monitor for marine mammals and implement shutdown/
delay procedures when applicable by calling for the shutdown to the 
hammer operator. Qualified observers are trained biologists, with the 
following minimum qualifications:
    (a) Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
    (b) Ability to conduct field observations and collect data 
according to assigned protocols;
    (c) Experience or training in the field identification of marine 
mammals, including the identification of behaviors;
    (d) Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
    (e) Writing skills sufficient to prepare a report of observations 
including but not limited to the number and species of marine mammals 
observed; dates and times when in-water construction activities were 
conducted; dates and times when in-water construction activities were 
suspended to avoid potential incidental injury from construction sound 
of marine mammals observed within a defined shutdown zone; and marine 
mammal behavior; and
    (f) Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    (2) Prior to the start of pile driving activity, the shutdown zone 
will be monitored for fifteen minutes to ensure that it is clear of 
marine mammals. Pile driving will only commence once observers have 
declared the shutdown zone clear of marine mammals; animals will be 
allowed to remain in the shutdown zone (i.e., must leave of their own 
volition) and their behavior will be monitored and documented. The 
shutdown zone may only be declared

[[Page 36376]]

clear, and pile driving started, when the entire shutdown zone is 
visible (i.e., when not obscured by dark, rain, fog, etc.). In 
addition, if such conditions should arise during impact pile driving 
that is already underway, the activity would be halted.
    (3) If a marine mammal approaches or enters the shutdown zone 
during the course of pile driving operations, activity will be halted 
and delayed until either the animal has voluntarily left and been 
visually confirmed beyond the shutdown zone or fifteen minutes have 
passed without re-detection of small cetaceans or pinnipeds and 30 
minutes for gray whales. Monitoring will be conducted throughout the 
time required to drive a pile and for thirty minutes following the 
conclusion of pile driving.

Sound Attenuation Devices

    The use of bubble curtains to reduce underwater sound from impact 
pile driving was considered prior to the start of the project but was 
determined to not be practicable. Use of a bubble curtain in a channel 
with substantial current may not be effective, as unconfined bubbles 
are likely to be swept away and confined curtain systems may be 
difficult to deploy effectively in high currents. Data gathered during 
monitoring of construction on the San Francisco-Oakland Bay Bridge 
indicated that no reduction in the overall linear sound level resulted 
from use of a bubble curtain in deep water with relatively strong 
current (Illingworth & Rodkin 2001). During project monitoring for pile 
driving associated with the Richmond-San Rafael Bridge, also in San 
Francisco Bay, it was observed that performance in moderate current was 
significantly reduced (Oestman et al., 2009). Lucke et al. (2011) also 
note that the effectiveness of most currently used curtain designs may 
be compromised in stronger currents and greater water depths. We 
believe that conditions (relatively deep water and strong tidal 
currents of up to 3 knots (kn)) at the project site would disperse the 
bubbles and compromise the effectiveness of sound attenuation.

Timing Restrictions

    In-order to avoid impacts to least tern populations when they are 
most likely to be foraging and nesting, in-water work will be 
concentrated from October 1-April 1 or, depending on circumstances, to 
April 30. However, this limitation is in accordance with agreements 
between the Navy and FWS, and is not a requirement of this proposed 
IHA. All in-water construction activities would occur only from 45 
minutes after sunrise to 45 minutes before sunset.

Soft Start

    The use of a soft start procedure is believed to provide additional 
protection to marine mammals by warning or providing a chance to leave 
the area prior to the hammer operating at full capacity, and typically 
involves a requirement to initiate sound from the hammer at reduced 
energy followed by a waiting period. This procedure is repeated two 
additional times. It is difficult to specify the reduction in energy 
for any given hammer because of variation across drivers and, for 
impact hammers, the actual number of strikes at reduced energy will 
vary because operating the hammer at less than full power results in 
``bouncing'' of the hammer as it strikes the pile, resulting in 
multiple ``strikes.'' The project will utilize soft start techniques 
for impact pile driving. We require an initial set of three strikes 
from the impact hammer at reduced energy, followed by a thirty-second 
waiting period, then two subsequent three strike sets. Soft start will 
be required at the beginning of each day's impact pile driving work and 
at any time following a cessation of impact pile driving of thirty 
minutes or longer; the requirement to implement soft start for impact 
driving is independent of whether vibratory driving has occurred within 
the prior thirty minutes.
    Based on our evaluation of the Navy's proposed measures, as well as 
any other potential measures that may be relevant to the specified 
activity, we have preliminarily determined that the proposed mitigation 
measures provide the means of effecting the least practicable impact on 
marine mammal species or stocks and their habitat, paying particular 
attention to rookeries, mating grounds, and areas of similar 
significance.

Proposed Monitoring and Reporting

    In order to issue an IHA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking.'' The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for 
incidental take authorizations must include the suggested means of 
accomplishing the necessary monitoring and reporting that will result 
in increased knowledge of the species and of the level of taking or 
impacts on populations of marine mammals that are expected to be 
present in the proposed action area. Effective reporting is critical 
both to compliance as well as ensuring that the most value is obtained 
from the required monitoring.
    Monitoring and reporting requirements prescribed by NMFS should 
contribute to improved understanding of one or more of the following:
     Occurrence of marine mammal species or stocks in the area 
in which take is anticipated (e.g., presence, abundance, distribution, 
density).
     Nature, scope, or context of likely marine mammal exposure 
to potential stressors/impacts (individual or cumulative, acute or 
chronic), through better understanding of: (1) Action or environment 
(e.g., source characterization, propagation, ambient noise); (2) 
Affected species (e.g., life history, dive patterns); (3) Co-occurrence 
of marine mammal species with the action; or (4) Biological or 
behavioral context of exposure (e.g., age, calving or feeding areas).
     Individual marine mammal responses (behavioral or 
physiological) to acoustic stressors (acute, chronic, or cumulative), 
other stressors, or impacts from multiple stressors.
     How anticipated responses to stressors impact either: (1) 
Long-term fitness and survival of an individual; or (2) Population, 
species, or stock.
     Effects on marine mammal habitat (e.g. marine mammal prey 
species, acoustic habitat, or other important physical components of 
marine mammal habitat).
     Mitigation and monitoring effectiveness.
    Please see the Monitoring Plan (available at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm) for full details of the 
requirements for monitoring and reporting. Notional monitoring 
locations (for biological and acoustic monitoring) are shown in Figures 
3-1 and 3-2 of the Plan. The purpose of this Plan is to provide 
protocols for acoustic and marine mammal monitoring implemented during 
pile driving and removal activities. We have preliminarily determined 
this monitoring plan, which is summarized here and which largely 
follows the monitoring strategies required and successfully implemented 
under the previous IHAs, to be sufficient to meet the MMPA's monitoring 
and reporting requirements. The previous monitoring plan was modified 
to integrate adaptive changes to the monitoring methodologies as well 
as updates to the scheduled construction activities. Monitoring 
objectives are as follows:
     Monitor in-water construction activities, including the 
implementation of in-situ acoustic monitoring efforts to

[[Page 36377]]

continue to measure SPLs from in-water construction and demolition 
activities not previously monitored or validated during the previous 
IHAs. This would include collection of acoustic data for activities and 
pile types for which sufficient data has not previously been collected, 
including for diamond saw cutting of caissons and pile clipping of the 
concrete piles during fuel pier demolition. The Navy also plans to 
collect acoustic data for vibratory extraction and/or driving, impact 
driving, jetting pile extraction and pile dead-pull of the concrete 
piles at NMAWC.
     Monitor marine mammal occurrence and behavior during in-
water construction activities to minimize marine mammal impacts and 
effectively document marine mammals occurring within ZOI boundaries.
    Collection of ambient underwater sound measurements in the absence 
of project activities has been concluded, as a rigorous baseline 
dataset for the project area has been developed.

Acoustic Measurements

    The primary purpose of acoustic monitoring is to empirically verify 
modeled injury and behavioral disturbance zones (defined at radial 
distances to NMFS-specified thresholds; see Estimated Take by 
Incidental Harassment). For non-pulsed sound, distances will continue 
to be evaluated for attenuation to the point at which sound becomes 
indistinguishable from background levels. Empirical acoustic monitoring 
data will be used to document transmission loss values determined from 
past measurements and to examine site-specific differences in SPL and 
affected ZOIs on an as needed basis.
    Should monitoring results indicate it is appropriate to do so, 
marine mammal mitigation zones may be revised as necessary to encompass 
actual ZOIs. Acoustic monitoring will be conducted as specified in the 
approved Monitoring Plan. Please see Table 2-2 of the Plan for a list 
of equipment to be used during acoustic monitoring. Monitoring 
locations will be determined based on results of previous acoustic 
monitoring effort and the best professional judgment of acoustic 
technicians.
    For activities such as demolition of the old fuel pier and 
temporary mooring dolphin, the Navy will continue to collect in situ 
acoustic data to validate source levels and ZOIs. Environmental data 
would be collected including but not limited to: Wind speed and 
direction, air temperature, humidity, surface water temperature, water 
depth, wave height, weather conditions and other factors that could 
contribute to influencing the airborne and underwater sound levels 
(e.g., aircraft, boats). Full details of acoustic monitoring 
requirements may be found in section 4.2 of the Navy's Monitoring Plan.

Visual Marine Mammal Observations

    The Navy will collect sighting data and behavioral responses to 
construction for marine mammal species observed in the region of 
activity during the period of activity. All observers will be trained 
in marine mammal identification and behaviors and are required to have 
no other construction-related tasks while conducting monitoring. The 
Navy will monitor the shutdown zone and disturbance zone before, 
during, and after pile driving as described under Proposed Mitigation 
and in the Monitoring Plan, with observers located at the best 
practicable vantage points. Notional monitoring locations are shown in 
Figures 3-3 and 3-4 of the Navy's Plan. Please see that plan, available 
at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm, for full 
details of the required marine mammal monitoring. Section 3.2 of the 
Plan and Section 13 of the Navy's application offer more detail 
regarding monitoring protocols. Based on our requirements, the Navy 
would implement the following procedures for pile driving:
     MMOs would be located at the best vantage point(s) in 
order to properly see the entire shutdown zone and as much of the 
disturbance zone as possible.
     During all observation periods, observers will use 
binoculars and the naked eye to search continuously for marine mammals.
     If the shutdown zones are obscured by fog or poor lighting 
conditions, pile driving at that location will not be initiated until 
that zone is visible. Should such conditions arise while impact driving 
is underway, the activity would be halted.
     The shutdown and disturbance zones around the pile will be 
monitored for the presence of marine mammals before, during, and after 
any pile driving or removal activity.
    One MMO will be placed in the most effective position near the 
active construction/demolition platform in order to observe the 
respective shutdown zones for vibratory and impact pile driving or for 
applicable demolition activities. Monitoring would be primarily 
dedicated to observing the shutdown zone; however, MMOs would record 
all marine mammal sightings beyond these distances provided it did not 
interfere with their effectiveness at carrying out the shutdown 
procedures. Additional land, pier, or vessel-based MMOs will be 
positioned to monitor the shutdown zones and the buffer zones, as 
notionally indicated in Figures 3-3 and 3-4 of the Navy's application.
    For all pile driving and applicable demolition activities, a 
minimum of one observer shall monitor the shutdown zones. However, any 
action requiring the impact or vibratory hammer will necessitate two 
MMOs. For impact and vibratory pile driving of 16-in concrete piles, 
two observers shall be positioned for optimal monitoring of the 
surrounding waters.
    The MMOs will record all visible marine mammal sightings. Confirmed 
takes will be registered once the sightings data has been overlaid with 
the isopleths identified in Table 5 and visualized in Figures 6-2, 6-3, 
and 6-4 of the Navy's application, or based on refined acoustic data, 
if amendments to the ZOIs are needed. Acousticians on duty may be 
noting SPLs in real-time, but, to avoid biasing the observations, will 
not communicate that information directly to the MMOs. These platforms 
may move closer to, or farther from, the source depending on whether 
received SPLs are less than or greater than the regulatory threshold 
values. All MMOs will be in radio communication with each other so that 
the MMOs will know when to anticipate incoming marine mammal species 
and when they are tracking the same animals observed elsewhere.
    If any species for which take is not authorized is observed by a 
MMO during applicable construction or demolition activities, all 
construction will be stopped immediately. Pile driving will commence if 
the animal has not been seen inside the Level B ZOI for at least one 
hour of observation. If the animal is resighted again, pile driving 
will be stopped and a boat-based MMO (if available) will follow the 
animal until it has left the Level B ZOI. If the animal is resighted 
again, pile driving will be stopped and a boat-based MMO (if available) 
will follow the animal until it has left the Level B ZOI.
    Individuals implementing the monitoring protocol will assess its 
effectiveness using an adaptive approach. Monitoring biologists will 
use their best professional judgment throughout implementation and seek 
improvements to these methods when deemed appropriate. Any 
modifications to protocol will be coordinated between NMFS and the 
Navy.

Data Collection

    We require that observers use approved data forms. Among other

[[Page 36378]]

pieces of information, the Navy will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, the Navy will attempt to 
distinguish between the number of individual animals taken and the 
number of incidents of take. We require that, at a minimum, the 
following information be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel and distance from 
pile driving activity, and if possible, the correlation to measured 
SPLs;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Description of implementation of mitigation measures 
(e.g., shutdown or delay);
     Locations of all marine mammal observations; and
     Other human activity in the area.
    In addition, photographs would be taken of any gray whales 
observed. These photographs would be submitted to NMFS' West Coast 
Regional Office for comparison with photo-identification catalogs to 
determine whether the whale is a member of the WNP population.

Reporting

    A draft report would be submitted to NMFS within 45 calendar days 
of the completion of marine mammal monitoring, or 60 days prior to the 
issuance of any subsequent IHA for this project, whichever comes first. 
The report will include marine mammal observations pre-activity, 
during-activity, and post-activity during pile driving days, and will 
also provide descriptions of any behavioral responses to construction 
activities by marine mammals and a complete description of all 
mitigation shutdowns and the results of those actions. A final report 
would be prepared and submitted within thirty days following resolution 
of comments on the draft report. Required contents of the monitoring 
reports are described in more detail in the Navy's Acoustic and Marine 
Species Monitoring Plan.

Monitoring Results From Previously Authorized Activities

    The Navy complied with the mitigation and monitoring required under 
the previous authorizations for this project. Acoustic and marine 
mammal monitoring was implemented as required, with marine mammal 
monitoring occurring before, during, and after each pile driving event. 
During the course of Year 4 activities, the Navy did not exceed the 
take levels authorized under the IHA (please see the Navy's monitoring 
report for more details and below for further discussion).
    The general objectives of the monitoring plan were similar to those 
described above for the Year 5 monitoring plan. For acoustic 
monitoring, the primary goal was to continue to collect in situ data 
towards validation of the acoustic ZOIs defined based on previous data 
collection efforts and using the transmission loss modeling effort 
conducted prior to the start of the project, and to continue collection 
of data on background noise conditions in San Diego Bay.
    Acoustic Monitoring Results--For a full description of acoustic 
monitoring methodology, please see section 2.3 of the Navy's monitoring 
report, including Figure 2-3 for representative monitoring locations. 
Results from Years 1-4 are displayed in Table 11. Please see our 
notices of proposed IHAs for the Years 2, 3, and 4 IHAs (79 FR 53026, 
September 5, 2014; 80 FR 53115, September 2, 2015; and 81 FR 66628, 
September 28, 2016) or the Navy's Year 1 and 2 monitoring reports for 
more detailed description of monitoring accomplished during the first 
two years of the project.
    For acoustic monitoring associated with impact pile driving, 
continuous hydroacoustic monitoring systems were positioned at source 
(10 m from the pile) and opportunistically at predicted 160-dB Level B 
ZOIs. The far-field data collections were conducted at multiple 
locations during impact driving of 16-in concrete-filled poly piles and 
24 x 30-in concrete fender piles, i.e., approximately 20 to 550 m from 
source. Hydrophones were deployed from the dock, barge, or moored 
vessel at half the water depth. The SPLs for driving of 30-in steel 
pipe piles were measured intermittently and archived (but not reported) 
because associated SPLs for the size, type, and location of the piles 
were previously validated. Source SPLs were recorded and analyzed for a 
minimum of five piles for each of the concrete pile types. Additional 
measurements were archived.
    SPLs of pile driving and demolition activities conducted during 
Year 2 fell within expected levels but varied spatially relative to the 
existing fuel pier structure and maximum source levels for individual 
piles (Table 11). For both vibratory and impact pile driving methods, 
results from the IPP (Year 1) and 2014/2015 production pile driving 
(Year 2) showed that transmission loss for piles driven in shallow 
water inside of the existing fuel pier was greater than piles driven in 
deep water outside of the existing pier. Differences in depth, sediment 
type, and existing in-water pier/wharf structures likely accounted for 
variations in transmission loss and measured differences in SPLs 
recorded at the shutdown and far-field locations for shallow versus 
deep piles of the same type and size. SPLs documented during vibratory 
and impact pile driving of shallow and deep steel pipe piles of the 
same size displayed notable differences in SPLs at shutdown range and 
to a lesser extent at source.
    Measurements of impact driving of concrete piles conducted during 
Year 3 produced greater than expected SPLs at source. Differences in 
the subsurface conditions may account for the discrepancy, as a 
hardened layer is found at approximately 20-40 m below the mudline. 
SPLs documented during driving of 16-in piles generally displayed 
relatively low sound source levels during initial driving then 
appreciable increases observed once the piles interacted with this 
layer. Measurements from driving of the square concrete piles showed 
greatest sound source levels during initial impact pile driving, which 
then decreased once the piles transitioned through the hardened layer. 
While source SPLs were observed to be greater than expected for both 
pile types, attenuation was also greater. Despite greater than expected 
source levels, the measured isopleth distances were similar to modeled 
predictions. Far-field impact pile driving results varied substantially 
between piles and locations for the various pile sizes, types, and 
locations. Both pile types were driven adjacent to the new fuel pier 
and source SPLs were subject to a wide variety of boundary conditions 
from recently driven piles and associated pier infrastructure. Further 
detail and discussion is provided in the Navy's report.
    During Year 4, measurements were conducted for pile clipping, 
caisson cutting, pile jetting, and airborne vibratory and impact 
driving. The average SPLs for pile clipping at source ranged from 138.0 
to 144.6 dB rms, with maximum SPLs at source ranging from

[[Page 36379]]

156.1 to 165.3 dB rms (see Table 6-3 of the Navy's monitoring report). 
Measurements were conducted on eight piles and took one to three 
minutes to cut.
    Caisson demolition was conducted on 18 84-in concrete-filled 
caissons, with an average duration of approximately 6 hours per 
caisson. Underwater acoustic data was collected for seven caissons 
using the vibratory setting. For some of the recordings, there were two 
caissons being cut simultaneously and the acousticians captured the 
SPLs for comparison between a single cutter versus two cutters. If two 
cutters were running, the distance measured was from the closest 
caisson to the location. Average SPLs at source for a single cutter 
were 136.1 and 141.4 dB rms. Maximum SPLs at source for a single cutter 
were 140.9 and 146.5 dB rms. Average SPLs at source for two cutters 
running simultaneously were 146.5 and 149.0 dB rms. Maximum SPLs at 
source for two cutters running simultaneously were 149.0 and 155.6 dB 
rms. On average, there was a 10 dB difference between a single cutter 
and two at source. Far-field recordings for a single cutter were 
collected at far-field locations ranging from 20 to 430 m (66 to 1,411 
ft), with documented maximum SPL values from 136.6 to 145.5 dB rms. 
Far-field recordings for two cutters were also collected at far-field 
locations ranging from 85 to 810 m (279 to 2,657 ft), with documented 
maximum SPL values from 133.2 to 146.8 dB rms.
    SPLs of pile installation activities for the 24 x 30 concrete piles 
had not been previously documented. The only jetting data collected 
during the Project was at NMAWC during the removal of 12-inch and 16-
inch concrete piles. A total of sixteen 24 x 30 concrete non-structural 
fender piles were driven using two techniques: (1) Method 1 (M1) 
utilized a custom-made spud jet with four nozzles welded to the tip 
that used a high-pressure water system (900 gallons per minute with a 
maximum pounds per square inch [psi] of 300), to make the initial break 
through the bay point formation sediment layer; and (2) Method 2 (M2) 
used the 24 x 30 pile, outfitted with two pipes inside the full length 
of the pile, which then used a high-pressure water system (maximum psi 
of 300) to remove sediment and place the pile. Pile jetting averaged 
24.5 minutes per pile and acoustic recordings were collected for the 
entire duration. Collection of underwater acoustic data were completed 
on six piles using the vibratory setting. For M1, the average sound 
pressure levels (SPL) at source ranged from 152.6 dB rms to 155.1 dB 
rms, and maximum SPLs at source ranged from 156.5 dB rms to 159.9 dB 
rms. For M2, the average SPL at source ranged from 133.0 dB to 149.8 dB 
and maximum SPLs at source ranged from 137.1 dB to 153.2 dB rms. A 
vessel based drift method was used to obtain far-field recordings 
during M1 and M2 jetting techniques; the vessel was initially 
positioned at the closest feasible distance to source, and then the 
allowed to drift on the natural tidal current until near ambient sound 
pressure levels were obtained. The SPLs at far-field for the first 
drift during jetting M1 reached near ambient at 165 m (541 ft) from 
pile with an SPL of 128.0 dB. The SPLs at far-field for the first drift 
during pile jetting M2 reached near ambient at 80 m (262 ft) from pile 
with an SPL of 127.6 dB. Recordings during the vessel drifts showed 
that jetting reached near ambient levels for both methods between 80 m 
(262 ft) and 165 m (541 ft; M1 and M2, respectively).
    Airborne sound levels were recorded during vibratory pile driving 
on fourteen 30-inch steel piles. The maximum recorded airborne dB rms 
values at source was 106.3 dB re 20 [mu]Pa, and average values ranged 
from 96.0 to 102.7 dB re 20 [mu]Pa. Airborne sound levels were recorded 
during impact pile driving on sixteen 30-inch steel piles. The maximum 
recorded airborne dB values at source was 118.5 dB re 20 [mu]Pa, and 
average values ranged from 105.8 to 112.5 dB re 20 [mu]Pa. Further 
detail and discussion is provided in the Navy's report.

                                Table 11--Acoustic Monitoring Results for Year 4
----------------------------------------------------------------------------------------------------------------
                                                                                      Average
                                                                    Number  of      underwater        Average
           Location                Activity         Pile type          piles        SPL at 10 m    airborne SPL
                                                                     measured        (dB rms)      (LZFmax) \1\
----------------------------------------------------------------------------------------------------------------
Fuel Pier (Year 4)...........  Pile Clipping...  24-in square                  4             141  ..............
                                                  concrete pile.
                               Caisson           84-in caisson..              10             136  ..............
                                Demolition (1
                                cutter).
                               Caisson           84-in caisson..               8             138  ..............
                                Demolition (2
                                cutters).
                               Vibratory.......  30-in steel (at               7  ..............             100
                                                  source).
                               Vibratory.......  30-in steel                   7  ..............              86
                                                  (far field).
                               Impact..........  30-in steel (at               9  ..............             110
                                                  source).
                               Impact..........  30-in steel                   7  ..............              88
                                                  (far field).
NMAWC (Year 4)...............  Pile Jetting....  24x30..........              10             147  ..............
----------------------------------------------------------------------------------------------------------------
\1\ Measured from Source (15.2 m) and Far-field Distances for 30-inch Steel Piles.

    Marine Mammal Monitoring Results--Marine mammal monitoring was 
conducted as required under the IHA and as described in the Year 4 
monitoring plan and in our Federal Register notice of proposed 
authorization associated with the Year 4 IHA. For a full description of 
monitoring methodology, please see section 2 of the Navy's monitoring 
report, including Figure 2-1, 2-2, and 2-7 for representative 
monitoring locations and Figures 2-2 through 2-5 for monitoring zones. 
Monitoring protocols were managed adaptively during the course of the 
fourth-year IHA. Multiple shutdowns were implemented due to marine 
mammals being observed within buffered shutdown zones, but no animals 
were observed within actual predicted Level A harassment zones while 
pile driving was occurring (one harbor seal was seen within the Level A 
ZOI after a shutdown of construction had been implemented).
    Monitoring results are presented in Table 12. The Navy recorded all 
observations of marine mammals, including pre- and post-construction 
monitoring efforts. Animals observed during these periods or that were 
determined to be outside relevant ZOIs were not considered to represent 
incidents of take. Please see Figures 3-11, 3-12, 3-22, 3-23, 3-30, and 
3-31 of the Navy's Monitoring Report for locations of observations and 
incidents of take relative to the project sites. Take authorization for 
the second-year authorization was informed by an assumption that 115 
days of in-water construction would occur, whereas only

[[Page 36380]]

fifty total days actually occurred. However, the actual observed rates 
per day were in all cases lower than what was assumed. Therefore, we 
expect that the Navy would not have exceeded the take allowances even 
if the full 115 days had been reached.
    There were considerably fewer individuals and sightings during the 
Year 3 IHA when compared to the same months during the Year 2 IHA, and 
only three species were observed. This may be due to environmental 
fluctuations as part of the on-going El Ni[ntilde]o event. Water 
temperatures during Year 3 were warmer than during the same months 
during Year 2. Although the temperatures were still higher than the 
average water temperatures for the region prior to the current El 
Ni[ntilde]o event, it shows that the event may have been dissipating. 
In addition, California sea lion strandings decreased. No evidently 
significant behavioral changes were reported.
    Similar to Year 3, there were considerably fewer individuals and 
sightings during the Year 4 IHA when compared to the same months during 
the Year 2 IHA, and only four species were observed. This may be due to 
environmental fluctuations as part of the on-going El Ni[ntilde]o 
event. Water temperatures during Year 4 were slightly warmer than 
during the same months during Year 2. Although the temperatures were 
still higher than the average water temperatures for the region prior 
to the current El Ni[ntilde]o event, it shows that the event may have 
been dissipating. In addition, California sea lion strandings 
decreased, but may be returning to numbers more commonly observed. No 
evidently significant behavioral changes were reported.

                              Table 12--Marine Mammal Monitoring Results for Year 4
----------------------------------------------------------------------------------------------------------------
                                                                                   Extrapolated
                                       Total           Total         Observed      incidents of        Total
             Species                 sightings      individuals    incidents  of   Level B  take     estimated
                                                                   Level B take         \1\        Level B take
----------------------------------------------------------------------------------------------------------------
California sea lion.............             717           2,037             156           1,835           1,991
Harbor seal.....................              87             102              21              57              78
Bottlenose dolphin..............              18              45               4             144             148
Gray whale......................               1               1               0              13              13
----------------------------------------------------------------------------------------------------------------
\1\ Assumed density and unmonitored area of assumed Level B ZOI used with actual pile driving time to generate
  assumed take for unmonitored areas.

Negligible Impact Analysis and Determination

    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. A negligible impact finding is based on the lack of likely 
adverse effects on annual rates of recruitment or survival (i.e., 
population-level effects). An estimate of the number of takes alone is 
not enough information on which to base an impact determination. In 
addition to considering estimates of the number of marine mammals that 
might be ``taken'' through harassment, NMFS considers other factors, 
such as the likely nature of any responses (e.g., intensity, duration), 
the context of any responses (e.g., critical reproductive time or 
location, migration), as well as effects on habitat, and the likely 
effectiveness of the mitigation. We also assess the number, intensity, 
and context of estimated takes by evaluating this information relative 
to population status. Consistent with the 1989 preamble for NMFS's 
implementing regulations (54 FR 40338; September 29, 1989), the impacts 
from other past and ongoing anthropogenic activities are incorporated 
into this analysis via their impacts on the environmental baseline 
(e.g., as reflected in the regulatory status of the species, population 
size and growth rate where known, ongoing sources of human-caused 
mortality, or ambient noise levels).
    Construction and demolition activities associated with the pier 
replacement project, as outlined previously, have the potential to 
disturb or displace marine mammals. Specifically, the specified 
activities may result in take, in the form of Level B harassment 
(behavioral disturbance) only, from underwater sounds generated from 
pile driving. Potential takes could occur if individuals of these 
species are present in the ensonified zone when pile driving or removal 
is happening.
    No injury, serious injury, or mortality is anticipated given the 
nature of the activity and measures designed to minimize the 
possibility of injury to marine mammals. The potential for these 
outcomes is minimized through the construction method and the 
implementation of the planned mitigation measures. Impact pile driving 
produces short, sharp pulses with higher peak levels and much sharper 
rise time to reach those peaks. When impact driving is necessary, 
required measures (implementation of buffered shutdown zones) 
significantly reduce any possibility of injury. Given sufficient 
``notice'' through use of soft start (for impact driving), marine 
mammals are expected to move away from a sound source that is annoying 
prior to its becoming potentially injurious. The likelihood that marine 
mammal detection ability by trained observers is high under the 
environmental conditions described for San Diego Bay (approaching 100 
percent detection rate, as described by trained biologists conducting 
site-specific surveys) further enables the implementation of shutdowns 
to avoid injury, serious injury, or mortality.
    Effects on individuals that are taken by Level B harassment, on the 
basis of reports in the literature as well as monitoring from past 
years of this project and other similar activities, will likely be 
limited to reactions such as increased swimming speeds, increased 
surfacing time, or decreased foraging (if such activity were occurring) 
(e.g., Thorson and Reyff, 2006; HDR, 2012; Lerma, 2014). Most likely, 
individuals will simply move away from the sound source and be 
temporarily displaced from the areas of pile driving, although even 
this reaction has been observed primarily only in association with 
impact pile driving. In response to vibratory driving, pinnipeds (which 
may become somewhat habituated to human activity in industrial or urban 
waterways) have been observed to orient towards and sometimes move 
towards the sound. The pile driving activities analyzed here are 
similar to, or less impactful than, numerous other construction 
activities conducted in San Francisco Bay and in the Puget Sound 
region, which have taken place with no

[[Page 36381]]

reported injuries or mortality to marine mammals, and no known long-
term adverse consequences from behavioral harassment. Repeated 
exposures of individuals to levels of sound that may cause Level B 
harassment are unlikely to result in hearing impairment or 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. Level B harassment will be reduced to the level of 
least practicable impact through use of mitigation measures described 
herein and, if sound produced by project activities is sufficiently 
disturbing, animals are likely to simply avoid the project area while 
the activity is occurring.
    In summary and as described above, the following factors primarily 
support our preliminary determination that the impacts resulting from 
this activity are not expected to adversely affect the species or stock 
through effects on annual rates of recruitment or survival:
     No mortality is anticipated or authorized;
     The anticipated incidents of Level B harassment consist 
of, at worst, temporary modifications in behavior;
     The absence of any significant habitat within the project 
area, including rookeries, significant haul-outs, or known areas or 
features of special significance for foraging or reproduction; and
     The presumed efficacy of the proposed mitigation measures 
in reducing the effects of the specified activity to the level of least 
practicable impact.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from the proposed activity will have a negligible impact on 
all affected marine mammal species or stocks.

Small Numbers

    As noted above, only small numbers of incidental take may be 
authorized under Section 101(a)(5)(D) of the MMPA for specified 
activities other than military readiness activities. The MMPA does not 
define small numbers and so, in practice, where estimated numbers are 
available, NMFS compares the number of individuals taken to the most 
appropriate estimation of abundance of the relevant species or stock in 
our determination of whether an authorization is limited to small 
numbers of marine mammals. Additionally, other qualitative factors may 
be considered in the analysis, such as the temporal or spatial scale of 
the activities.
    The number of incidents of take proposed for authorization for 
these stocks, with the exception of the coastal bottlenose dolphin (see 
below), would be considered small relative to the relevant stocks or 
populations (see Table 9) even if each estimated taking occurred to a 
new individual. This is an extremely unlikely scenario as, for 
pinnipeds occurring at the NBPL waterfront, there will almost certainly 
be some overlap in individuals present day-to-day and in general, there 
is likely to be some overlap in individuals present day-to-day for 
animals in estuarine/inland waters.
    The proposed numbers of authorized take for bottlenose dolphins are 
higher relative to the total stock abundance estimate and would not 
represent small numbers if a significant portion of the take was for a 
new individual. However, these numbers represent the estimated 
incidents of take, not the number of individuals taken. That is, it is 
likely that a relatively small subset of California coastal bottlenose 
dolphins would be incidentally harassed by project activities. 
California coastal bottlenose dolphins range from San Francisco Bay to 
San Diego (and south into Mexico) and the specified activity would be 
stationary within an enclosed water body that is not recognized as an 
area of any special significance for coastal bottlenose dolphins (and 
is therefore not an area of dolphin aggregation, as evident in Navy 
observational records). We therefore believe that the estimated numbers 
of takes, were they to occur, likely represent repeated exposures of a 
much smaller number of bottlenose dolphins and that, based on the 
limited region of exposure in comparison with the known distribution of 
the coastal bottlenose dolphin, these estimated incidents of take 
represent small numbers of bottlenose dolphins.
    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.

Impact on Availability of Affected Species for Taking for Subsistence 
Uses

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

Endangered Species Act (ESA)

    Section 7(a)(2) of the Endangered Species Act of 1973 (ESA: 16 
U.S.C. 1531 et seq.) requires that each Federal agency insure that any 
action it authorizes, funds, or carries out is not likely to jeopardize 
the continued existence of any endangered or threatened species or 
result in the destruction or adverse modification of designated 
critical habitat. To ensure ESA compliance for the issuance of IHAs, 
NMFS consults internally, in this case with the ESA Interagency 
Cooperation Division, whenever we propose to authorize take for 
endangered or threatened species.
    The Navy initiated informal consultation under section 7 of the ESA 
with NMFS Southwest Regional Office (now West Coast Regional Office) on 
March 5, 2013. NMFS concluded on May 16, 2013, that the proposed action 
may affect, but is not likely to adversely affect, WNP gray whales. The 
Navy has not requested authorization of the incidental take of WNP gray 
whales and no such authorization is proposed, and there are no other 
ESA-listed marine mammals found in the action area. Therefore, no 
consultation under the ESA is required.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to the Navy for conducting the described pier replacement 
activities in San Diego Bay, for a period of one year from the date of 
issuance, provided the previously mentioned mitigation, monitoring, and 
reporting requirements are incorporated. This section contains a draft 
of the IHA itself. The wording contained in this section is proposed 
for inclusion in the IHA (if issued).
    1. This Incidental Harassment Authorization (IHA) is valid from 
October 8, 2017, through October 7, 2018.
    2. This IHA is valid only for pile driving and removal activities 
associated with the Fuel Pier Replacement Project at the Naval Station 
Point Loma in San Diego Bay, California.

[[Page 36382]]

    3. General Conditions
    (a) A copy of this IHA must be in the possession of the Navy, its 
designees, and work crew personnel operating under the authority of 
this IHA.
    (b) The species authorized for taking are the harbor seal (Phoca 
vitulina richardii), California sea lion (Zalophus californianus), 
bottlenose dolphin (Tursiops truncatus truncatus), common dolphin 
(Delphinus delphis), northern elephant seal (Mirounga angustirostris), 
Pacific white-sided dolphin (Lagenorhynchus obliquidens), Risso's 
dolphin (Grampus griseus), and gray whale (Eschrichtius robustus).
    (c) The taking, by Level B harassment only, is limited to the 
species listed in condition 3(b). See Table 1 for numbers of take 
authorized.

              Table 1--Authorized Take Numbers, by Species
------------------------------------------------------------------------
                                                            Authorized
                         Species                               take
------------------------------------------------------------------------
California sea lion.....................................           8,971
Harbor seal.............................................             281
Northern elephant seal..................................              43
California coastal bottlenose dolphin...................             704
Common dolphin..........................................             861
Pacific white-sided dolphin.............................              28
Risso's dolphin.........................................             114
Gray whale..............................................              10
------------------------------------------------------------------------

    (d) The taking by injury (Level A harassment), serious injury, or 
death of any of the species listed in condition 3(b) of the 
Authorization or any taking of any other species of marine mammal is 
prohibited and may result in the modification, suspension, or 
revocation of this IHA.
    (e) The Navy shall conduct briefings between construction 
supervisors and crews, marine mammal monitoring team, acoustic 
monitoring team, and Navy staff prior to the start of all pile driving 
activity, and when new personnel join the work, in order to explain 
responsibilities, communication procedures, marine mammal monitoring 
protocol, and operational procedures.
    4. Mitigation Measures
    The holder of this Authorization is required to implement the 
following mitigation measures:
    (a) For all pile driving, the Navy shall implement a minimum 
shutdown zone of 10 m radius around the pile. If a marine mammal comes 
within or approaches the shutdown zone, such operations shall cease. 
See Table 2 for minimum radial distances required for shutdown zones.

                    Table 2--Radial Distance to Shutdown and Disturbance Zones Associated With Relevant Thresholds, Including Buffers
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Monitored distances to thresholds (meters)
                                                                 ---------------------------------------------------------------------------------------
                                                                                             Underwater                                   Airborne
                                                                 ---------------------------------------------------------------------------------------
                            Activity                                                Level A                          Level B               Level B
                                                                 ---------------------------------------------------------------------------------------
                                                                                                                           120 dB
                                                                    LF \1\     MF \1\     PW \1\     OW \1\     160 dB      \2\       100 dB     90 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                 Old Fuel Pier and Temporary Mooring Dolphin Demolition
--------------------------------------------------------------------------------------------------------------------------------------------------------
66-inch and 84-inch caissons (Diamond saw cutting)..............                      10                            N/A        631         N/A \3\
                                                                 --------------------------------------------
Concrete piles (Pile clipping)..................................                      10                            N/A      2,511
                                                                 ------------------------------------------------------------------
30-inch steel piles (Plasma torch cutting)......................                      10
                                                                           N/A
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                            NMAWC Construction and Demolition
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch concrete piles (Vibratory extraction/driving)...........         20 \4\
                                                                           10                 N/A      1,848         42        149
                                                                 --------------------------------------------
16-inch concrete piles (Impact driving).........................         100 \5\
                                                                         60 \6\               270        N/A
--------------------------------------------------------------------------------------------------------------------------------------------------------
16-inch concrete piles (Jetting pile extraction)................                      10                            N/A      1,165         N/A \3\
                                                                 ------------------------------------------------------------------
16-inch concrete piles (Pile dead-pull).........................                      10
                                                                           N/A
 
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ LF = Low-frequency cetaceans; MF = Mid-frequency cetaceans; PW = Phocid pinnipeds; OW = Otariid pinnipeds. The high-frequency cetacean hearing group
  (HF) is omitted, because no species in the hearing group occur in, or around, Project area.
\2\ Mean ambient sound levels in San Diego Bay are approximately 128 dB rms (NAVFAC SW 2015), and all 120 dB Level B ZOIs are based on the ambient
  value.
\3\ Airborne noise levels did not exceed regulatory thresholds during previous IHAs. No airborne monitoring will take place for diamond saw cutting of
  caissons, plasma torch cutting of temporary mooring dolphin 30-inch steel piles, jetting or dead-pull extraction of concrete piles.
\4\ Includes buffer of calculated Level A threshold out to 20 m (65.6 ft).
\5\ Includes buffer of calculated Level A threshold out to 100 m (328 ft).
\6\ Includes buffer of calculated Level A threshold out to 60 m (197 ft).

    (b) The Navy shall shutdown activity as appropriate upon 
observation of any species for which take is not authorized. Activity 
shall not be resumed until those species have been observed to leave 
the relevant zone or until one hour has elapsed.
    (c) The Navy shall deploy marine mammal observers as described 
below and as indicated in the Acoustic and Marine Species Monitoring 
Plan (Monitoring Plan; attached).
    i. For all pile driving and applicable demolition activities, a 
minimum of one observer shall monitor the shutdown zones. However, any 
action requiring the impact or vibratory hammer will necessitate two 
MMOs.
    ii. For impact and vibratory pile driving of 16-in concrete piles, 
two observers shall be positioned for optimal monitoring of the 
surrounding waters.

[[Page 36383]]

    iii. These observers shall record all observations of marine 
mammals, regardless of distance from the pile being driven, as well as 
behavior and potential behavioral reactions of the animals.
    iv. All observers shall be equipped for communication of marine 
mammal observations amongst themselves and to other relevant personnel 
(e.g., those necessary to effect activity delay or shutdown).
    (d) Monitoring shall take place from fifteen minutes prior to 
initiation of pile driving activity through thirty minutes post-
completion of pile driving activity. Pre-activity monitoring shall be 
conducted for fifteen minutes to ensure that the shutdown zone is clear 
of marine mammals, and pile driving may commence when observers have 
declared the shutdown zone clear of marine mammals. In the event of a 
delay or shutdown of activity resulting from marine mammals in the 
shutdown zone, animals shall be allowed to remain in the shutdown zone 
(i.e., must leave of their own volition) and their behavior shall be 
monitored and documented. Monitoring shall occur throughout the time 
required to drive a pile. The shutdown zone must be determined to be 
clear during periods of good visibility (i.e., the entire shutdown zone 
and surrounding waters must be visible to the naked eye).
    (e) If a marine mammal approaches or enters the shutdown zone, all 
pile driving activities at that location shall be halted. If pile 
driving is halted or delayed due to the presence of a marine mammal, 
the activity may not commence or resume until either the animal has 
voluntarily left and been visually confirmed beyond the shutdown zone 
or 30 minutes have passed without re-detection of gray whales or 15 
minutes for all other animals.
    (f) Monitoring shall be conducted by qualified observers, as 
described in the Monitoring Plan. Trained observers shall be placed 
from the best vantage point(s) practicable to monitor for marine 
mammals and implement shutdown or delay procedures when applicable 
through communication with the equipment operator.
    (g) The Navy shall use soft start techniques recommended by NMFS 
for impact pile driving. Soft start for impact drivers requires 
contractors to provide an initial set of strikes at reduced energy, 
followed by a thirty-second waiting period, then two subsequent reduced 
energy strike sets. Soft start shall be implemented at the start of 
each day's impact pile driving and at any time following cessation of 
impact pile driving for a period of 30 minutes or longer.
    (h) Pile driving shall only be conducted during daylight hours.
    5. Monitoring
    The holder of this Authorization is required to conduct marine 
mammal monitoring during pile driving activity. Marine mammal 
monitoring and reporting shall be conducted in accordance with the 
Monitoring Plan.
    (a) The Navy shall collect sighting data and behavioral responses 
to pile driving for marine mammal species observed in the region of 
activity during the period of activity. All observers shall be trained 
in marine mammal identification and behaviors, and shall have no other 
construction-related tasks while conducting monitoring.
    (b) For all marine mammal monitoring, the information shall be 
recorded as described in the Monitoring Plan.
    (c) The Navy shall conduct acoustic monitoring for representative 
scenarios of pile driving activity, as described in the Monitoring 
Plan.
    6. Reporting
    The holder of this Authorization is required to:
    (a) Submit a draft report on all monitoring conducted under the IHA 
within 45 calendar days of the completion of marine mammal and acoustic 
monitoring, or 60 days prior to the issuance of any subsequent IHA for 
this project, whichever comes first. A final report shall be prepared 
and submitted within thirty days following resolution of comments on 
the draft report from NMFS. This report must contain the informational 
elements described in the Monitoring Plan, at minimum (see attached), 
and shall also include:
    i. Detailed information about any implementation of shutdowns, 
including the distance of animals to the pile and description of 
specific actions that ensued and resulting behavior of the animal, if 
any.
    ii. Description of attempts to distinguish between the number of 
individual animals taken and the number of incidences of take, such as 
ability to track groups or individuals.
    iii. Results of acoustic monitoring, including the information 
described in in the Monitoring Plan.
    (b) Reporting injured or dead marine mammals:
    i. In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by this IHA, 
such as an injury (Level A harassment), serious injury, or mortality, 
Navy shall immediately cease the specified activities and report the 
incident to the Office of Protected Resources, NMFS, and the West Coast 
Regional Stranding Coordinator, NMFS. The report must include the 
following information:
    A. Time and date of the incident;
    B. Description of the incident;
    C. Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
    D. Description of all marine mammal observations in the 24 hours 
preceding the incident;
    E. Species identification or description of the animal(s) involved;
    F. Fate of the animal(s); and
    G. Photographs or video footage of the animal(s).
    Activities shall not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS will work with Navy to 
determine what measures are necessary to minimize the likelihood of 
further prohibited take and ensure MMPA compliance. Navy may not resume 
their activities until notified by NMFS.
    i. In the event that Navy discovers an injured or dead marine 
mammal, and the lead observer determines that the cause of the injury 
or death is unknown and the death is relatively recent (e.g., in less 
than a moderate state of decomposition), Navy shall immediately report 
the incident to the Office of Protected Resources, NMFS, and the West 
Coast Regional Stranding Coordinator, NMFS.
    The report must include the same information identified in 6(b)(i) 
of this IHA. Activities may continue while NMFS reviews the 
circumstances of the incident. NMFS will work with Navy to determine 
whether additional mitigation measures or modifications to the 
activities are appropriate.
    ii. In the event that Navy discovers an injured or dead marine 
mammal, and the lead observer determines that the injury or death is 
not associated with or related to the activities authorized in the IHA 
(e.g., previously wounded animal, carcass with moderate to advanced 
decomposition, scavenger damage), Navy shall report the incident to the 
Office of Protected Resources, NMFS, and the West Coast Regional 
Stranding Coordinator, NMFS, within 24 hours of the discovery. Navy 
shall provide photographs or video footage or other documentation of 
the stranded animal sighting to NMFS.
    7. This Authorization may be modified, suspended or withdrawn if 
the holder fails to abide by the conditions prescribed herein, or if 
the authorized taking is having more than a negligible impact on the 
species or stock of affected marine mammals.

[[Page 36384]]

Request for Public Comments

    We request comment on our analysis, the draft authorization, and 
any other aspect of this Notice of Proposed IHA for Navy's pier 
replacement activities. Please include with your comments any 
supporting data or literature citations to help inform our final 
decision on Navy's request for an MMPA authorization.

    Dated: August 1, 2017.
Catherine Marzin,
Acting Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2017-16453 Filed 8-3-17; 8:45 am]
BILLING CODE 3510-22-P