[Federal Register Volume 80, Number 170 (Wednesday, September 2, 2015)]
[Notices]
[Pages 53115-53135]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-21647]
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DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
RIN 0648-XE057
Takes of Marine Mammals Incidental to Specified Activities;
Taking Marine Mammals Incidental to a Pier Replacement Project
AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and
Atmospheric Administration (NOAA), Commerce.
ACTION: Notice; proposed incidental harassment authorization; request
for comments.
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SUMMARY: NMFS has received a request from the U.S. Navy (Navy) for
authorization to take marine mammals incidental to construction
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.
DATES: Comments and information must be received no later than October
2, 2015.
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
[[Page 53116]]
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: Ben Laws, Office of Protected
Resources, NMFS, (301) 427-8401.
SUPPLEMENTARY INFORMATION:
Availability
An electronic copy of the Navy's application and supporting
documents, as well as a list of the references cited in this document,
may be obtained by visiting the Internet at: www.nmfs.noaa.gov/pr/permits/incidental/construction.htm. In case of problems accessing
these documents, please call the contact listed above.
National Environmental Policy Act (NEPA)
The Navy prepared an Environmental Assessment (EA; 2013) for this
project. We subsequently adopted the EA and signed our own Finding of
No Significant Impact (FONSI) prior to issuing the first IHA for this
project, in accordance with NEPA and the regulations published by the
Council on Environmental Quality. Information in the Navy's
application, the Navy's EA, and this notice collectively provide the
environmental information related to proposed issuance of this IHA for
public review and comment. All documents are available at the
aforementioned Web site. We will review all comments submitted in
response to this notice as we complete the NEPA process, including a
decision of whether to reaffirm the existing FONSI, prior to a final
decision on the incidental take authorization request.
Background
Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.)
direct the Secretary of Commerce to allow, upon request, the
incidental, but not intentional, taking of small numbers of marine
mammals by U.S. citizens who engage in a specified activity (other than
commercial fishing) within a specified geographical region if certain
findings are made and either regulations are issued or, if the taking
is limited to harassment, a notice of a proposed authorization is
provided to the public for review.
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.''
Section 101(a)(5)(D) of the MMPA established an expedited process
by which citizens of the U.S. can apply for an authorization to
incidentally take small numbers of marine mammals by harassment.
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of
an application followed by a 30-day public notice and comment period on
any proposed authorizations for the incidental harassment of marine
mammals. Within 45 days of the close of the comment period, NMFS must
either issue or deny the authorization. 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].''
Summary of Request
On June 12, 2015, we received a request from the Navy for
authorization to take marine mammals incidental to pile installation
and removal associated with a pier replacement project in San Diego Bay
at Naval Base Point Loma in San Diego, CA (NBPL). The Navy also
submitted a separate monitoring plan and draft monitoring report
pursuant to requirements of the previous IHA. The Navy submitted
revised versions of the request on July 3 and July 26, 2015, a revised
version of the monitoring plan on July 21, 2015, and a revised
monitoring report on July 29, 2015. These documents were deemed
adequate and complete. The pier replacement project is planned to occur
over four years; this proposed IHA would cover only the third 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 use of both vibratory and impact pile driving is expected to
produce underwater sound at levels that have the potential to result in
behavioral harassment of marine mammals. 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.
This would be the third such IHA, if issued, following the IHAs
issued effective from September 1, 2013, through August 31, 2014 (78 FR
44539) and from October 8, 2014, through October 7, 2015 (79 FR 65378).
Monitoring reports are available on the Internet 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
[[Page 53117]]
life and does not meet current construction standards.
Over the course of four years, 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
third year of construction (the specified activity considered under
this proposed IHA), approximately 226 piles would be installed
(including six 30-in steel pipe piles, 88 30 x 24-in concrete piles,
and 132 16-in concrete-filled fiberglass piles). Demolition of the
existing pier would continue concurrently, including the removal of
approximately one hundred steel and concrete piles and twenty concrete-
filled steel caissons. Removals may occur by multiple means, including
vibratory removal, pile cutter, dead pull, and diamond belt saw, as
determined to be most effective. Construction work under this proposed
IHA is anticipated to require a total of 115 days of in-water work. All
steel piles will be driven with a vibratory hammer for their initial
embedment depths and finished with an impact hammer, as necessary.
The proposed actions with the potential to incidentally harass
marine mammals within the waters adjacent to NBPL are vibratory and
impact pile installation and removal of piles via pile cutter.
Vibratory pile removal is not planned but could occur if deemed the
most effective technique to remove a given pile; because this technique
is not expected to occur we do not consider it separately in this
document from vibratory pile driving. Concurrent use of multiple pile
driving rigs is not planned; however, pile removal conducted as part of
demolition activities (which could occur via a number of techniques)
may occur concurrently with pile installation conducted as part of
construction activities.
Dates and Duration
The entire project is scheduled to occur from 2013-17; the proposed
activities that would be authorized by this IHA, during the third year
of work, 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, as described below, 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 work would primarily occur from October through
April. In-water pile driving and removal work using pile cutters or
vibratory drivers would be limited to 115 days in total under this
proposed IHA. Pile driving would occur during normal working hours
(approximately 7 a.m. to 6 p.m.).
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 km and a total area of roughly 4,500 ha. The width of the
bay ranges from 0.3 to 5.8 km, and depths range from 23 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
ourFederal 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 third work window. Please see section 1 of the Navy's
application for full detail of construction scheduling for this period.
Approximately 498 piles in total are planned to be installed for the
project, including steel, concrete, and plastic piles. For the second
year of work, approximately 226 steel and concrete piles would be
installed. Tables 1 and 2 detail the piles to be installed and removed,
respectively, under this proposed 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 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.
We generally require that vibratory driving be used to the maximum
extent feasible, considering project design requirements and site
conditions. Steel piles are typically vibratory-driven for their
initial embedment depths or to refusal and finished with an impact
hammer for proofing or until the pile meets structural requirements
(potentially an approximate 25-125 blows), as necessary. Proofing
involves striking a driven pile with an impact hammer to verify that it
provides the required load-bearing capacity, as indicated by the number
of hammer blows per foot of pile advancement. Non-steel piles are
typically impact-driven for their entire embedment depth, in part
because non-steel piles are often displacement piles (as opposed
[[Page 53118]]
to pipe piles) and require some impact to allow substrate penetration.
Methods, Pile Removal--There are multiple methods for pile removal.
Piles were generally removed during the second year construction period
by cutting at the mudline, which can be accomplished in various ways.
Piles are expected to be removed during this third-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 (the application of a focused stream of water under
high pressure) 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 included here as contingency in the
event other methods of extraction are not successful.
Table 1--Details of Piles To Be Installed
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Purpose Location Planned timing Pile type Pile number
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Dolphin batter piles............. North mooring...... Fall 2015.......... 30-in steel pipe... 6
Fender piles..................... Bayward side of new Fall-Winter 2015... 24 x 30-in concrete 88
pier.
Fender piles..................... Bayward side of new Fall-Winter 2015... 16-in concrete- 132
pier. filled fiberglass.
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Construction--Construction work during the proposed third year of
activity would include driving of steel pipe piles to complete
construction of the northern mooring dolphin and driving of concrete
and concrete-filled fiberglass fender piles on the bayward section of
the new pier. The concrete piles (primary fender piles) will be
installed by first stabbing with the crane, before being jetted to
within approximately five feet of design tip elevation, then driven
using an impact hammer to tip elevation. The concrete-filled fiberglass
piles (secondary and corner fender piles) would be stabbed with the
crane before being impact driven. This work is expected to require a
total of 61 days.
Demolition--Demolition of the north segment of the existing pier
will be conducted during construction activity. Much of the demolition
work will be above-water, involving removal of decking, utilities, and
appurtenances, 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 54 days in total. Pile removal using no-impact
methods (e.g., dry pull) may continue outside the in-water work window.
Table 2--Details of Piles To Be Removed
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Pile type Number
------------------------------------------------------------------------
Concrete fender piles (14-, 16-, and 24-in).................. 56
Plastic fender piles (13-in)................................. 34
Temporary steel piles (30-in)................................ 12
Concrete-filled steel caissons............................... 20
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Description of Work Accomplished
During the first in-water work season, two primary activities were
conducted: Relocation of the Marine Mammal Program and the Indicator
Pile Program (IPP). During the second in-water work season, the IPP was
concluded and simultaneous construction of the new pier and demolition
of the old pier begun.
The Navy Marine Mammal Program, administered by Space and Naval
Warfare Systems Command Systems Center, was moved approximately three
kilometers to the Naval Mine and Anti-submarine Warfare Command (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 initially 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 was begun 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
one hundred days of activity from October 16, 2014, through April 29,
2015. Of these one hundred days of in-water work, eighteen days
involved only impact driving, fifteen 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. Additional work may be
conducted under the existing IHA between September 15 and October 7,
2015, in which case the submitted
[[Page 53119]]
monitoring report would be amended as necessary.
Description of Marine Mammals in the Area of the Specified Activity
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 recently observed within the
bay. 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 due to developing El Ni[ntilde]o conditions 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 both 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., 2015) 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. capensis capensis). 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 species.
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.
We have reviewed the Navy's detailed species descriptions,
including life history information, for accuracy and completeness and
refer the reader to Sections 3 and 4 of the Navy's application instead
of reprinting the information here. Please also refer to NMFS' Web site
(www.nmfs.noaa.gov/pr/species/mammals) for generalized species accounts
and to the Navy's Marine Resource Assessment for the Southern
California and Point Mugu Operating Areas, which provides information
regarding the biology and behavior of the marine resources that may
occur in those operating areas (DoN, 2008). The document is publicly
available at www.navfac.navy.mil/products_and_services/ev/products_and_services/marine_resources/marine_resource_assessments.html
(accessed August 21, 2015). In addition, we provided information for
the potentially affected stocks, including details of stock-wide
status, trends, and threats, 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) and
refer the reader to those documents rather than reprinting the
information here.
Table 3 lists the marine mammal species with expected potential for
occurrence in the vicinity of NBPL during the project timeframe and
summarizes key information regarding stock status and abundance. See
also Figures 3-1 through 3-5 of the Navy's application for observed
occurrence of marine mammals in the project area. Taxonomically, we
follow Committee on Taxonomy (2014). Please see NMFS' Stock Assessment
Reports (SAR), available at www.nmfs.noaa.gov/pr/sars, for more
detailed accounts of these stocks' status and abundance. All
potentially affected species are addressed in the Pacific SARs
(Carretta et al., 2015).
Table 3--Marine Mammals Potentially Present in the Vicinity of NBPL
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Stock abundance (CV, Relative occurrence
Species Stock ESA/ MMPA status; Nmin, most recent PBR \3\ Annual M/ in San Diego Bay;
Strategic (Y/N) \1\ abundance survey) \2\ SI \4\ season of occurrence
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Order Cetartiodactyla--Cetacea--Superfamily Mysticeti (baleen whales)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Eschrichtiidae
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Gray whale......................... Eastern North Pacific -; N 20,990 (0.05; 20,125; 624 \6\ 132 Occasional migratory
2011). visitor; winter.
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Superfamily Odontoceti (toothed whales, dolphins, and porpoises)
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Delphinidae
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Bottlenose dolphin................. California coastal... -; N 323 \5\ (0.13; 290; 2.4 0.2 Common; year-round.
2005).
Short-beaked common dolphin........ California/Oregon/ -; N 411,211 (0.21; 3,440 64 Occasional; year-
Washington. 343,990; 2008). round (but more
common in warm
season).
Long-beaked common dolphin......... California........... -; N 107,016 (0.42; 610 13.8 Occasional; year-
76,224; 2009). round (but more
common in warm
season).
[[Page 53120]]
Pacific white-sided dolphin........ California/Oregon/ -; N 26,930 (0.28; 21,406; 171 17.8 Uncommon; year-round.
Washington. 2008).
Risso's dolphin.................... California/Oregon/ -; N 6,272 (0.3; 4,913; 39 1.6 Rare; year-round (but
Washington. 2008). more common in cool
season).
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Order Carnivora--Superfamily Pinnipedia
--------------------------------------------------------------------------------------------------------------------------------------------------------
Family Otariidae (eared seals and sea lions)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion................ U.S.................. -; N 296,750 (n/a; 9,200 389 Abundant; year-round.
153,337; 2011).
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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).
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\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.
\5\This value is based on photographic mark-recapture surveys conducted along the San Diego coast in 2004-05, but is considered a likely underestimate,
as it does not reflect that approximately 35 percent of dolphins encountered lack identifiable dorsal fin marks (Defran and Weller, 1999). If 35
percent of all animals lack distinguishing marks, then the true population size would be closer to 450-500 animals (Carretta et al., 2015).
\6\Includes annual Russian harvest of 127 whales.
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.
Potential Effects of the Specified Activity on Marine Mammals and Their
Habitat
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 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
[[Page 53121]]
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 decibels (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 hertz (Hz). Typical human hearing ranges from 20 Hz to
20 kilohertz (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%. 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
an 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.
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.
The mitigation strategies described below largely follow those
required and successfully implemented under the first- and second-year
IHAs. For this proposed IHA, data from acoustic monitoring conducted
during the first two 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 prevent 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 180/190 dB rms acoustic injury criteria.
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 7. For certain activities, the shutdown zone would not exist
because source levels are lower than the threshold, or the source
levels indicate that the radial distance to the threshold would be less
than 10 m. However, a minimum shutdown zone of 20 m will be established
during all pile driving and removal activities, regardless of the
estimated zone. This represents a buffer of 10 m added to the
previously implemented 10 m minimum shutdown 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.
The Navy considered typical swim speeds (Godfrey, 1985; Lockyer and
Morris, 1987; Fish, 1997; Fish et al., 2003; Rohr et al., 2002; Noren
et al., 2006) and past field experience (e.g., typical elapsed time
from observation of an animal to shutdown of equipment) in initially
defining these buffered zones, and then evaluated the practicality and
effectiveness of the zones during the Year 2 construction period. The
Navy will add a buffer of 75 m to the 190 dB zone for impact driving of
steel piles (doubling the effective zone to 150 m radius) and will add
a buffer of 100 m to the 180 dB zone for impact driving of steel piles
(increasing the effective zone to 450 m). These zones are also shown in
Table 7. 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.
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
[[Page 53122]]
later (see ``Proposed Monitoring and Reporting''). Nominal radial
distances for disturbance zones are shown in Table 7.
In order to document observed incidences 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 third 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:
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;
Advanced education in biological science or related field
(undergraduate degree or higher is required);
Experience and ability to conduct field observations and
collect data according to assigned protocols (this may include academic
experience);
Experience or training in the field identification of
marine mammals, including the identification of behaviors;
Sufficient training, orientation, or experience with the
construction operation to provide for personal safety during
observations;
Writing skills sufficient to prepare a report of
observations including but not limited to the number and species of
marine mammals observed; dates and times when in-water construction
activities were conducted; dates and times when in-water construction
activities were suspended to avoid potential incidental injury from
construction sound of marine mammals observed within a defined shutdown
zone; and marine mammal behavior; and
Ability to communicate orally, by radio or in person, with
project personnel to provide real-time information on marine mammals
observed in the area as necessary.
(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 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 the animal. 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, and the distance to the 190 dB zone was considered to be the
same with and without the bubble curtain (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 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 during
daylight hours (sunrise to sunset).
[[Page 53123]]
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 both impact and vibratory pile driving of steel piles. We require
the Navy to initiate sound from vibratory hammers for fifteen seconds
at reduced energy followed by a thirty-second waiting period, with the
procedure repeated two additional times. For impact 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 pile driving work and at any time following a cessation of pile
driving of thirty minutes or longer; these requirements are specific to
both vibratory and impact driving and the requirement. For example, the
requirement to implement soft start for impact driving is independent
of whether vibratory driving has occurred within the past thirty
minutes.
We have carefully evaluated the Navy's proposed mitigation measures
and considered their effectiveness in past implementation to
preliminarily determine whether they are likely to effect the least
practicable impact on the affected marine mammal species and stocks and
their habitat. Our evaluation of potential measures included
consideration of the following factors in relation to one another: (1)
The manner in which, and the degree to which, the successful
implementation of the measure is expected to minimize adverse impacts
to marine mammals, (2) the proven or likely efficacy of the specific
measure to minimize adverse impacts as planned; and (3) the
practicability of the measure for applicant implementation.
Any mitigation measure(s) we prescribe should be able to
accomplish, have a reasonable likelihood of accomplishing (based on
current science), or contribute to the accomplishment of one or more of
the general goals listed below:
(1) Avoidance or minimization of injury or death of marine mammals
wherever possible (goals 2, 3, and 4 may contribute to this goal).
(2) A reduction in the number (total number or number at
biologically important time or location) of individual marine mammals
exposed to stimuli expected to result in incidental take (this goal may
contribute to 1, above, or to reducing takes by behavioral harassment
only).
(3) A reduction in the number (total number or number at
biologically important time or location) of times any individual marine
mammal would be exposed to stimuli expected to result in incidental
take (this goal may contribute to 1, above, or to reducing takes by
behavioral harassment only).
(4) A reduction in the intensity of exposure to stimuli expected to
result in incidental take (this goal may contribute to 1, above, or to
reducing the severity of behavioral harassment only).
(5) Avoidance or minimization of adverse effects to marine mammal
habitat, paying particular attention to the prey base, blockage or
limitation of passage to or from biologically important areas,
permanent destruction of habitat, or temporary disturbance of habitat
during a biologically important time.
(6) For monitoring directly related to mitigation, an increase in
the probability of detecting marine mammals, thus allowing for more
effective implementation of the mitigation.
Based on our evaluation of 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.
Any monitoring requirement we prescribe should improve our
understanding of one or more of the following:
Occurrence of marine mammal species in action area (e.g.,
presence, abundance, distribution, density).
Nature, scope, or context of likely marine mammal exposure
to potential stressors/impacts (individual or cumulative, acute or
chronic), through better understanding of: (1) Action or environment
(e.g., source characterization, propagation, ambient noise); (2)
Affected species (e.g., life history, dive patterns); (3) Co-occurrence
of marine mammal species with the action; or (4) Biological or
behavioral context of exposure (e.g., age, calving or feeding areas).
Individual responses to acute stressors, or impacts of
chronic exposures (behavioral or physiological).
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 and resultant impacts to
marine mammals.
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 continue to
measure SPLs from in-water construction and demolition activities not
previously monitored or validated during the previous IHAs. At minimum,
[[Page 53124]]
acoustic sound levels would be collected and evaluated acoustic for
five piles of each type of fender pile to be installed.
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.
Continue the collection of ambient underwater sound
measurements in the absence of project activities to develop a rigorous
baseline for the project area.
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 of 160-, 180-, and 190-dB (rms)
for underwater sound (where applicable) and 90- and 100-dB (unweighted)
for airborne sound; see ``Estimated Take by Incidental Harassment''
below). 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 measurements
collected during the IPP 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 would be revised as necessary to
encompass actual ZOIs in subsequent years of the fuel pier replacement
project. 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.
Some details of the methodology include:
No acoustic data to be collected for 30-in steel piles as
sufficient data has been collected for 36-in steel piles during
previous two years. One airborne sound monitoring station will be
maintained.
Hydroacoustic monitoring to be conducted at source for
impact driving of a minimum of five of each type of fender pile in
order to document SPLs.
Sound level meters to be deployed to continue validation
of source SPLs and 160/120 dB ZOIs as documented from previous acoustic
monitoring efforts.
Source SPLs for all construction or demolition activities
will be measured for the first five events of each size or type of pile
or activity if not sufficiently measured and/or validated previously;
Navy would conduct additional monitoring if source unexpectedly exceeds
any assumed values.
For underwater recordings, sound level meter systems will
follow methods in accordance with NMFS' 2012 guidance for the
collection of source levels.
For airborne recordings, to the extent that logistics and
security allow, reference recordings will be collected at approximately
15 m from the source via a sound meter with integrated microphone.
Other distances may also be utilized to obtain better data if the
signal cannot be isolated clearly due to other sound sources (e.g.,
barges or generators).
Ambient conditions will be measured at the project site in
the absence of construction activities to determine background sound
levels. Ambient levels will be recorded over the frequency range from 7
Hz to 20 kHz. Ambient conditions will be recorded at least three times
during the IHA period consistent with NMFS' 2012 guidance for the
measurement of ambient sound. Each time, data will be collected for
eight-hour periods for three days during typical working hours (7 a.m.
to 6 p.m., Monday through Saturday) in the absence of in-water
construction activities. The three recording periods will be spaced to
adequately capture variation across the notional work window (October-
March).
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).
From all the strikes associated with each pile occurring
during the Level 4 (highest energy) phase these measures will be made:
[cir] Mean, minimum, and maximum rms pressure level in dB
[cir] Mean duration of a pile strike (based on the ninety percent
energy criterion)
[cir] Number of hammer strikes
[cir] Mean, minimum, and maximum single strike SEL in dB re
[mu]Pa\2\ sec
[cir] Cumulative SEL as defined by the mean single strike SEL +
10*log (# hammer strikes) in dB re [mu]Pa\2\ sec
[cir] A frequency spectrum (pressure spectral density) in [dB re
[mu]Pa\2\ per Hz] based on the average of up to eight successive
strikes with similar sound. Spectral resolution will be 1 Hz and the
spectrum will cover nominal range from 7 Hz to 20 kHz.
Full details of acoustic monitoring requirements may be found in
section 3.2 of the Navy's approved Monitoring Plan and in section 13 of
the Navy's application.
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 3-1 and 3-2 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 4.2
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 on 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
[[Page 53125]]
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 3-1 and 3-2 of the Navy's application.
Up to five additional MMOs will be deployed during driving of steel
piles, and at least one additional MMOs will be deployed during driving
of fender piles and during applicable demolition activities.
Because there are different threshold distances for different types
of marine mammals (pinniped and cetacean), the observation platform at
the shutdown zone will concentrate on the 190 dB rms and 180 dB rms
isopleths locations and station the observers and vessels accordingly.
The MMOs associated with these platforms 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 7 and
visualized (for steel piles) in Figure 6-2 of the Navy's application,
or based on refined acoustic data, if amendments to the ZOIs are
needed. The acousticians on board will 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. If a boat is available, MMOs
will follow the animal(s) at a minimum distance of 100 m until the
animal has left the Level B ZOI. 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.
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
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 sixty 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 2 activities, the Navy did not exceed the
take levels authorized under the IHA. However, the Navy did record four
observations of California sea lions within the defined 190-dB shutdown
zone (please see Appendix H of 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 three monitoring plan. For acoustic
monitoring, the primary goal was to continue validation of the acoustic
ZOI contours utilizing hydroacoustic measurements collected during the
IPP and production pile driving to update estimated SPL contours
(isopleths) developed from the transmission loss modeling effort
conducted prior to the start of the project and to collect more data to
validate the transmission loss model. The Navy previously conducted
acoustic monitoring for pile driving of steel pile associated with the
IPP and production driving and for concrete piles associated with the
temporary relocation of the Navy's Marine Mammal Program.
Acoustic Monitoring Results--For a full description of acoustic
monitoring methodology, please see section 2.3 of the Navy's monitoring
report, including Figure 2-1 for representative monitoring locations.
Results from Years 1 and 2 are displayed in Table 4. Please see our
notice of proposed IHA for the Year 2 IHA (79 FR 53026; September 5,
2014) or the Navy's Year 1 monitoring report for more detailed
description of monitoring accomplished during Year 1.
For acoustic monitoring associated with production pile driving, a
continuous hydroacoustic monitoring systems were positioned at source
(10 m from the pile), in the vicinity of the predicted 180-dB
behavioral ZOI for impact driving (225-400 m), and opportunistically at
far-field Level B ZOIs predicted on the basis of past monitoring and
measurements of
[[Page 53126]]
ambient noise in the bay (see Figure 2-1 in the Navy's monitoring
report). Hydrophones were deployed from the dock, barge, or moored
vessel at half the water depth. Pile locations and corresponding SPL
measurements of pile driving activities were partitioned into shallow
water and deep water; SPLs for shallow pile driving activities were
only measured intermittently because associated SPLs were previously
validated. Airborne sound measurements were also collected
intermittently, but in sufficient amounts to continue validation of
airborne ZOIs for pinniped species. SPLs were recorded and analyzed for
greater than ten percent of all pile driving of 30- 36-in steel pipe
piles driven in deep water. Additionally, pile driving of temporary 18-
in steel pipe piles, 36-in abutment steel pipe piles, and demolition of
existing pier structural members (caissons and fender piles) were
measured to document SPLs associated with each construction activity.
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 4). 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.
Vibratory SPLs were generally as expected. Results calculated for
sound source levels of two 30-in steel pipe piles and nineteen 36-in
steel pipe piles showed SPLs ranging from 160-178 dB rms. Average
maximum SPLs varied approximately 13 dB rms with nominal differences
between pile sizes. Evaluation of transmission loss displayed similar
results to previously modeled outcomes, with the distance at which
vibratory sound sources levels were indistinguishable from ambient SPLs
approximately 2,500-3,000 m from the source.
For impact driving, measurements during production pile driving
showed maximum SPL values at source ranging from 192-204 dB rms, with
the highest values being for 36-in piles driven in deeper water. Four
temporary 18-in steel pipe piles were impact driven to support the
existing pier structure, with reported results of 184 dB rms at 10 m.
Validated SPLs of impact and vibratory pile driving of deep 36-in steel
pipe piles were less than, but in relative agreement, with those
estimated from the transmission loss model used to establish ZOIs for
Year 2. Differences in measured ZOIs from transmission loss model
results were expected given the inherent variation in pile source
strength and propagation conditions, and are not considered
significant.
Measurements were made during both soft start and normal driving
for both vibratory and impact driving. A gradual building of SPLs
during startup of vibratory pile driving can be observed (see Figure 3-
2 of the Navy's monitoring report) but soft start SPLs were not notably
different from full production driving and varied considerably between
piles and locations based on the depth of the pile and underlying
substrate. The vibratory soft start process was evaluated for five of
the nineteen measured piles at both source and shutdown with
corresponding soft start SPLs averaged across all three pulses of the
soft start procedure and compared to full production vibratory pile
driving SPLs. The resulting soft start SPLs averaged 1.8 dB rms less
than full production vibratory pile driving at source; however, of the
five measured events, only two showed an increased SPL during full
power driving and SPLs were actually higher during soft start for one
event. Soft start vibratory SPLs where mostly much lower during the
initial pulse but on average where not significantly different than
SPLs recorded at source or at shutdown during full production vibratory
driving (see Table 3-3 of the Navy's monitoring report). Soft start SPL
values for impact driving ranged between 10 and 15 dB rms lower than
full energy production impact pile driving SPLs, depending on the
individual pile sizes and locations (see Figure 3-8 of the Navy's
monitoring report.
Table 4--Acoustic Monitoring Results
--------------------------------------------------------------------------------------------------------------------------------------------------------
Measured distances to relevant zones (dB rms/
Number of Average Average dB unweighted) (m) \1\
Location Activity Pile type piles underwater airborne ---------------------------------------------
measured SPL at 10 m SPL at 15 m 90 100
(dB rms) (LZFmax) 120 160 180 190 \4\ \4\
--------------------------------------------------------------------------------------------------------------------------------------------------------
NMAWC.......................... Impact........... 12- and 16-in 58 182 108 n/a 126 13 <10 728 105
concrete.
------------- -------------
Fuel Pier (Year 1)............. Vibratory........ 30- and 36-in 9 167 \2\ n/a <10 <10 233 71
steel pipe. 113 3,000
Impact........... 36-in steel pipe. 7 200 n/a \3\ \3\ \3\
2,500 450 75
------------- -------------
Fuel Pier (Year 2) \7\......... Vibratory........ 30-in steel pipe. 2 165
Impact........... 30-in steel pipe. 2 196 107
-------------
Vibratory........ 36-in steel pipe. 31 178 2,500 n/a <10 <10 182 78
Impact........... 36-in steel pipe. 31 204 n/a 2,000 350 75
------------- -------------
Hydraulic cutting 24-in concrete 4 \5\ 154
pile.
Diamond saw 72-in caisson.... 4 \6\ 155
cutting.
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Site-specific measured transmission loss values (both underwater and airborne) were used to calculate zone distances. See monitoring report for more
detail.
\2\ The 120-dB disturbance zone was initially modeled to be 6,470 m; however, ambient sound in the vicinity of the project site was measured at
approximately 128 dB rms (see below). This value was used in conjunction with a site-specific propagation model to arrive at a predicted distance of
3,000 m at which sound should attenuate to background levels. This was supported by collection of measured dB rms values for vibratory pile driving
during the IPP, as signal could not be distinguished from background at similar distance.
\3\ These values are for outside piles. Measured distances to the 160/180/190 dB ZOIs for inside piles were 2,000/100/40 m (see above for discussion).
Zones calculated on the basis of SPLs from 36-in piles.
\4\ Distances based on impact driving.
\5\ This activity was measured as an impulsive sound, as the sound production was intermittent as the hydraulic compression of the cutter broke through
different layers. This sound source is considerd to be continuous for purposes of exposure estimation and mitigation.
\6\ Value measured at 15 m from source.
\7\ Year 2 values are maximum values rather than average. We use these in defining conservative ZOIs.
[[Page 53127]]
Ambient data collection was conducted in a manner consistent with
NMFS' 2012 guidance for measurement of background sound. Ambient
underwater and airborne sound level recordings were collected for three
eight-hour days in December 2014, and March, April, and May 2015.
Ambient sound level recordings were collected in the absence of
construction activities, and during typical construction time periods
(7 a.m. to 6 p.m.), at locations that were between 400 and 700 m from
each site. Sites were chosen to minimize boat traffic effects that
might impact results.
Ambient hydroacoustic sound level recordings conducted adjacent to
the fuel pier project site documented per-deployment ninetieth
percentile averages from 122-131 dB rms, with an overall mean of
approximately 130 dB. Removal of outlying values produced a an overall
fiftieth percentile value of approximately 128 dB rms, consistent with
previous measured values and within expected ranges.
Marine Mammal Monitoring Results--Marine mammal monitoring was
conducted as required under the IHA and as described in the Year 2
monitoring plan and in our Federal Register notice of proposed
authorization associated with the Year 2 IHA (79 FR 53026; September 5,
2014). For a full description of monitoring methodology, please see
section 2.4 of the Navy's monitoring report, including Figure 2-1 for
representative monitoring locations and Figure 2-2 for monitoring
zones. Monitoring protocols were managed adaptively during the course
of the second-year IHA. For example, evaluated the use of the shutdown
zone buffers described under ``Proposed Mitigation''.
Monitoring results are presented in Table 5. 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 3-22, 3-27, 3-31, 3-35, 3-38, and
3-39 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 135 days of in-water construction
would occur, whereas only 100 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 135 days had been reached. In addition
to the results shown in Table 5, the Navy observed a mixed group of one
bottlenose dolphin and two common dolphins, unidentified delphinids
(ten sightings of 227 individuals), unidentified large whales (four
sightings of nine individuals), and unidentified pinnipeds (35
sightings of 35 individuals). None of these were within an active Level
B harassment zone.
As noted above, four individual California sea lions were observed
within the defined 190-dB shutdown zone. After correcting for animal
location based on distance and bearing relative to the observer, the
distance from the animals to the piles ranged from 20-60 m. Pile
driving activity was immediately halted upon observation of the animals
within the shutdown zones. In all cases, the animals were observed
following the shutdown and no unusual behaviors or indicators of
distress were noted. Event-specific reports are available in Appendix H
of the Navy's monitoring report.
There were a total of thirty sightings of dead California sea lions
in the water and additional reports of emaciated individuals in the
water, or on docks, piers, and barges in the vicinity of the project.
All dead animals were evaluated and deemed as having died as a result
of factors unrelated to the project, likely due to the unusual
mortality event currently ongoing in southern California waters. All
such observations were appropriately reported in accordance with the
IHA and per protocols agreed-upon with NMFS' regional stranding
coordinator.
Table 5--Marine Mammal Monitoring Results
----------------------------------------------------------------------------------------------------------------
Total
Species Total Total incidents of
sightings individuals Level B take
----------------------------------------------------------------------------------------------------------------
California sea lion............................................. 5,397 7,507 \2\ \3\ 2,509
Harbor seal..................................................... 241 248 \3\ 70
Bottlenose dolphin.............................................. 247 695 \3\ 250
Gray whale...................................................... 3 5 0
Common dolphin.................................................. 20 850 38
Pacific white-sided dolphin \1\................................. 7 27 0
Northern elephant seal \1\...................................... 2 1 0
Steller sea lion \1\............................................ 1 1 0
Short-finned pilot whale \1\.................................... 1 1 0
----------------------------------------------------------------------------------------------------------------
\1\ No take was authorized for these species. A single juvenile elephant seal was observed hauled out on shore
on two occasions.
\2\ Twelve individuals were considered taken by Level B harassment due to exposure to airborne noise. These
individuals were observed within the airborne ZOI and did not enter the water during the course of pile
driving activity.
\3\ Take numbers include thirteen unidentified pinnipeds and one unidentified dolphin, assumed on the basis of
MMO observation notes to be eleven California sea lions, two harbor seals, and a bottlenose dolphin.
Estimated Take by Incidental Harassment
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].''
All anticipated takes would be by Level B harassment resulting from
vibratory and impact pile driving or demolition and involving temporary
changes in behavior. The proposed mitigation and monitoring measures
(i.e., buffered shutdown zones) are expected to minimize the
possibility of Level A harassment such that we believe it is unlikely.
We do not expect that injurious or lethal takes would occur even in the
absence of the planned mitigation and monitoring measures.
[[Page 53128]]
If a marine mammal responds to a stimulus by changing its behavior
(e.g., through relatively minor changes in locomotion direction/speed
or vocalization behavior), the response may or may not constitute
taking at the individual level, and is unlikely to affect the stock or
the species as a whole. However, if a sound source displaces marine
mammals from an important feeding or breeding area for a prolonged
period, impacts on animals or on the stock or species could potentially
be significant (e.g., Lusseau and Bejder, 2007; Weilgart, 2007). Given
the many uncertainties in predicting the quantity and types of impacts
of sound on marine mammals, it is common practice to estimate how many
animals are likely to be present within a particular distance of a
given activity, or exposed to a particular level of sound. In practice,
depending on the amount of information available to characterize daily
and seasonal movement and distribution of affected marine mammals, it
can be difficult to distinguish between the number of individuals
harassed and the instances of harassment and, when duration of the
activity is considered, it can result in a take estimate that
overestimates the number of individuals harassed. In particular, for
stationary activities, it is more likely that some smaller number of
individuals may accrue a number of incidences of harassment per
individual than for each incidence to accrue to a new individual,
especially if those individuals display some degree of residency or
site fidelity and the impetus to use the site (e.g., because of
foraging opportunities) is stronger than the deterrence presented by
the harassing activity.
The project area is not believed to be particularly important
habitat for marine mammals, nor is it considered an area frequented by
marine mammals (with the exception of California sea lions, which are
attracted to nearby haul-out opportunities). Sightings of other species
are relatively rare. Therefore, behavioral disturbances that could
result from anthropogenic sound associated with these activities are
expected to affect only a relatively small number of individual marine
mammals, although those effects could be recurring over the life of the
project if the same individuals remain in the project vicinity.
The Navy has requested authorization for the potential taking of
small numbers of California sea lions, harbor seals, bottlenose
dolphins, common dolphins, Pacific white-sided dolphins, Risso's
dolphins, northern elephant seals, and gray whales in San Diego Bay and
nearby waters that may result from pile driving during construction
activities associated with the fuel pier replacement project described
previously in this document. In order to estimate the potential
incidents of take that may occur incidental to the specified activity,
we typically first estimate the extent of the sound field that may be
produced by the activity and then consider in combination with
information about marine mammal density or abundance in the project
area. In this case, we have acoustic data from project monitoring that
provides empirical information regarding the sound fields likely
produced by project activities. We first provide information on
applicable sound thresholds for determining effects to marine mammals
before describing the measured sound fields, the available marine
mammal density or abundance information, and the method of estimating
potential incidents of take.
Sound Thresholds
We use generic sound exposure thresholds to determine when an
activity that produces sound might result in impacts to a marine mammal
such that a take by harassment might occur. To date, no studies have
been conducted that explicitly examine impacts to marine mammals from
pile driving sounds or from which empirical sound thresholds have been
established. These thresholds (Table 6) are used to estimate when
harassment may occur (i.e., when an animal is exposed to levels equal
to or exceeding the relevant criterion) in specific contexts; however,
useful contextual information that may inform our assessment of effects
is typically lacking and we consider these thresholds as step
functions. NMFS is working to revise these acoustic guidelines; for
more information on that process, please visit www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
Table 6--Current Acoustic Exposure Criteria
------------------------------------------------------------------------
Criterion Definition Threshold
------------------------------------------------------------------------
Level A harassment (underwater). Injury (PTS--any 180 dB (cetaceans)/
level above that 190 dB
which is known to (pinnipeds)
cause TTS). (rms).
Level B harassment (underwater). Behavioral 160 dB (impulsive
disruption. source)/120 dB
(continuous
source) (rms).
Level B harassment (airborne)... Behavioral 90 dB (harbor
disruption. seals)/100 dB
(other pinnipeds)
(unweighted).
------------------------------------------------------------------------
Distance to Sound Thresholds
Background information on underwater sound propagation and the
calculation of range to relevant thresholds was provided in our Federal
Register notice of proposed authorization associated with the first-
year IHA (78 FR 30873; May 23, 2013). For the first-year IHA, the Navy
estimated sound fields using a site-specific model for transmission
loss (TL) from pile driving at a central point at the project site in
combination with proxy source levels (as described in the
aforementioned Federal Register notice). The model is based on
historical temperature-salinity data and location-dependent bathymetry.
In the model, TL is the same for different sound source levels and is
applied to each of the different activities to determine the point at
which the applicable thresholds are reached as a function of distance
from the source. The model's predictions result in a slightly lower
average rate of TL than practical spreading, and hence are
conservative. The model has been further validated using acoustic
monitoring data collected under the first- and second-year IHAs (see
Figure 6-1 of the Navy's application).
Impact and vibratory driving of steel pipe piles, impact driving of
concrete and concrete-filled fiberglass piles, and demolition via pile
cutting (and potentially vibratory removal) is planned for the next
phase of work. Acoustic monitoring results that inform both the take
estimates as well as the mitigation monitoring zones were reported in
Table 4. We present the measured distances again here (Table 7) and
compare to the modeled zones used in estimating potential incidents of
take for the first year IHA. See also Figure
[[Page 53129]]
6-2 of the Navy's application for visual representation of these sound
fields and their interaction with local topography. Assumed proxy
source levels for the first-year IHA were 195 dB rms and 180 dB rms for
impact and vibratory driving of steel piles, respectively. Measured
source levels, used to produce the values labeled as ``measured''
below, were 196 dB rms and 165 dB rms for impact and vibratory driving,
respectively. We conservatively use the vibratory pile installation
value as proxy for vibratory pile removal, if it occurs. For vibratory
driving, background sound has been determined to be approximately 128
dB rms. The distance at which continuous sound produced by vibratory
driving would attenuate to background levels is approximately 3,000 m.
Although Year 2 measurements indicate that such attenuation may occur
closer to 2,500 m, we conservatively retain the larger distance for
estimating exposures.
Because we have no new measurements for the two types of fender
piles, we use the same proxy source values as were originally presented
in the Navy's EA and first-year IHA application. There are no available
values for 24 x 30-in square concrete piles, but there are measurements
available for 24-in octagonal concrete piles (see Table 6-4 of the
Navy's application). We use the largest such value (176 dB rms;
Caltrans, 2012). There are also no available measurements for concrete-
filled fiberglass piles, so we use a proxy value from driving of 16-in
solid concrete piles (173 dB rms; Caltrans, 2012). The ZOI ranges for
these piles are as presented in the original documents, and are
therefore conservative in comparison with the revised TL curve shown in
Figure 6-1 of the Navy's application.
The Navy measured several demolition activities during the Year 2
IHA (hydraulic pile cutting, diamond saw cutting) with results ranging
from approximately 152-155 dB rms. Using these and the TL curve, the
Navy estimates a ZOI range of approximately 1,500 m. However, based on
empirical evidence from the prior two years of monitoring effort, the
Navy states that attenuation to background levels for these activities
may be closer to 1,000 m, making the assumed ZOI very conservative.
Continued acoustic monitoring efforts should provide further data
relating to these activities. For airborne sound, we assume a single,
precautionary zone here that is based on measured values for impact
driving of steel piles (approximately 107 dB [unweighted]).
Table 7--Predicted Versus Measured Distances to Relevant Thresholds
--------------------------------------------------------------------------------------------------------------------------------------------------------
Distance to threshold in meters
Activity -----------------------------------------------------------------------------------------------
190 dB 180 dB 160 dB 120 dB 100 dB 90 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact driving, steel piles (predicted)................. 36 452 5,484 n/a 113 358
Impact driving, steel piles (measured) \1\.............. \2\ 75 \2\ 350 2,000 n/a 78 182
Vibratory driving, steel piles (predicted).............. <10 14 n/a 6,470 9 28
Vibratory driving, steel piles (measured)............... <10 <10 n/a 3,000 .............. ..............
Impact driving, 24x30 concrete piles.................... <10 <10 505 n/a .............. ..............
Impact driving, 16-in concrete-filled fiberglass piles.. <10 <10 259 n/a .............. ..............
Pile cutting (demolition)............................... <10 <10 n/a 1,500 .............. ..............
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Note that, for underwater zones, these values are based on data for bayside piles and will be precautionary for shoreside piles. See discussion at
Table 4.
\2\ The buffered zones for use in mitigation will be 150 m and 450 m, respectively. The minimum zone for other activities listed here will be 20 m.
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), the majority of such fixed areas are not within
the ZOIs for airborne sound. The zones for sea lions are within the
minimum shutdown zone defined for underwater sound. Accordingly, we
previously stated that incidents of incidental take resulting solely
from airborne sound are unlikely. However, due to the additional
surfaces available for California sea lions to haul out on during
construction activity, twelve individuals were unexpectedly observed
during Year 2 monitoring as hauled out within the airborne ZOI and did
not subsequently enter the water during pile driving. Therefore, these
animals were considered taken by airborne noise and we consider that
this could occur again during Year 3 construction activity. 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.
Marine Mammal Densities
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 site-specific marine
mammal surveys, from 2007-14 (Merkel and Associates, 2008; Johnson,
2010, 2011; Lerma, 2012, 2014). Boat survey transects established
within northern San Diego Bay in 2007 have been resurveyed on 46
occasions, 35 of which were conducted between September and April.
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. 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. These data are from
dedicated line-transect surveys, required project marine mammal
monitoring, or from opportunistic observations for more rarely observed
species (see Figures 3-1 through 3-5 of the Navy's application).
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
[[Page 53130]]
(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. Density information is shown in Table 9; the
document is publicly available on the Internet at: nwtteis.com/DocumentsandReferences/NWTTDocuments/SupportingTechnicalDocuments.aspx
(accessed August 24, 2015).
Description of Take Calculation
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 8; and,
Exposures to sound levels at or above the relevant
thresholds equate to take, as defined by the MMPA.
The estimation of marine mammal takes typically uses the following
calculation:
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
n * ZOI produces an estimate of the abundance of animals that could
be present in the area for exposure, and is rounded to the nearest
whole number before multiplying by days of total activity.
The ZOI impact area is estimated using the relevant distances in
Table 7, 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). When local abundance is the best available
information, in lieu of the density-area method described above, we may
simply multiply some number of animals (as determined through counts of
animals hauled-out) by the number of days of activity, under the
assumption that all of those animals will be present and incidentally
taken on each day of activity.
------------------------------------------------------------------------
Activity Number of days ZOI (km\2\)
------------------------------------------------------------------------
Impact and vibratory driving, 30-in 6 5.6572
steel piles \1\........................
Vibratory removal....................... 6 5.6572
Impact driving, 24x32-in concrete piles. 22 0.1914
Impact driving, 16-in concrete-filled 33 0.0834
fiberglass piles.......................
Hydraulic pile cutting/diamond saw 48 3.0786
cutting................................
------------------------------------------------------------------------
\1\ We assume that impact driving of 30-in steel piles would always
occur on the same day as vibratory driving of the same piles.
Therefore, the impact driving ZOI (3.8894 km\2\) would always be
subsumed by the vibratory driving ZOI.
Where appropriate, we use average daily number of individuals
observed within the project area during Navy marine mammal surveys
converted to a density value by using the largest ZOI as the effective
observation area. It is the opinion of the professional biologists who
conducted these surveys that detectability of animals during these
surveys, at slow speeds and under calm weather and excellent viewing
conditions, approached one hundred percent.
There are a number of reasons why estimates of potential incidents
of take may be conservative, assuming that available density or
abundance estimates and estimated ZOI areas are accurate (aside from
the contingency correction discussed above). 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
The NMSDD reports estimated densities for north and central San
Diego Bay of 5.8 animals/km\2\ for the summer and fall periods and 2.5
animals/km\2\ during the winter and spring (based on surveys conducted
2007-11; note that the NMSDD does not present density estimates
specific to San Diego Bay for other species). For the first-year IHA,
the Navy reported an average abundance of approximately sixty
individuals per survey day (approximately equating to the reported
density). However, Year 2 project monitoring showed an average of 90.35
individuals per day occurring within the project area (i.e., 5.6752
km\2\). This includes both hauled-out and swimming individuals. For
California sea lions, the most common species in northern San Diego Bay
and the only species with regular occurrence in the project area, we
determined that this value--derived from the most recent monitoring
effort--would be appropriate for use in estimating potential incidents
of take. As noted previously, we also account separately for the
potential that California sea lions may experience Level B harassment
solely as a result of airborne noise. There is no firm quantitative
basis on which to base an estimate of potential occurrences of
harassment by airborne noise, as use of the aforementioned density
estimate would not be appropriate, California sea lion use of
opportunistic haul-outs within the airborne ZOI is not predictable, and
the potential reaction of hauled animals to airborne noise (i.e.,
whether hauled sea lions enter the water during construction activity
and are subsequently exposed to underwater noise or remain hauled for
the duration) is also not predictable. Therefore, we assume and propose
to authorize the take of ten individual California sea lions solely by
airborne noise.
Harbor Seal
Harbor seals are relatively uncommon within San Diego Bay.
Previously,
[[Page 53131]]
sightings in the Navy transect surveys of northern San Diego Bay were
limited to individuals outside of the ZOI, on the south side of Ballast
Point. These individuals had not been observed entering or transiting
the project area and were believed to move from this location to haul-
outs further north at La Jolla. Separately, marine mammal monitoring
conducted by the Navy intermittently from 2010-14 had documented up to
four harbor seals near Pier 122 (within the ZOI) at various times, with
the greatest number of sightings during April and May. This information
was used in the previous IHA analysis, wherein we assumed that three
harbor seals could be present for up to thirty days of the project.
However, Year 2 project monitoring indicates an average abundance of
2.83 individuals per day in the project area. Animals were seen
swimming as well as hauled out on rocks along the shoreline of NBPL.
Although it is unknown whether this increase in abundance is a
temporary phenomenon we use this new information on a precautionary
basis as the best available information, and assume that this number of
animals could be present on any day of the project. The NMSDD provides
a maximum density estimate of 0.02 animals/km\2\ for southern
California, but site-specific information indicates that harbor seals
are more common within the northern San Diego Bay project area than
this density would suggest.
Gray Whale
The NMSDD provides a density of 0.115 animals/km\2\ for southern
California waters from shore to 5 nm west of the Channel Islands
(winter/spring only; density assumed to be zero during summer/fall), a
value initially reported by Carretta et al. (2000) for gray whales
around San Clemente Island in the Southern California Bight. Gray
whales were seen only from January-April. In the project area,
observational data for gray whales is limited and their occurrence
considered infrequent and unpredictable. On the basis of limited
information--in recent years, solitary individuals have entered the bay
and remained for varying lengths of time in 2009, 2010, 2011, and 2014,
and whales more regularly transit briefly past the mouth of San Diego
Bay--we assume here that the NMSDD density is applicable, while
acknowledging that it likely represents a precautionary estimate for
waters within the Bay as opposed to those outside the mouth of the bay
that whales are more likely to transit through. Incidental harassment
of gray whales could result from some combination of individuals
briefly transiting near the mouth of the bay and from individuals
entering the bay and lingering in the project area.
Bottlenose Dolphin
Coastal bottlenose dolphins can occur at any time of year in San
Diego Bay. Numbers sighted during Navy transect surveys have been
highly variable, ranging from zero to forty individuals (observed
dolphins are assumed to have been of the coastal stock). An uncorrected
average of 2.1 bottlenose dolphins was observed during recent Navy
surveys (September 2012 through April 2014), although nineteen animals
were observed in a single survey. As reported in the NMSDD, Dudzik et
al. (2006) provide a uniform density for California coastal dolphins of
0.4 animals/km\2\ within 1 km of the coast from Baja to San Francisco
in all four seasons. However, given the high variability observed in
terms of numbers and locations of bottlenose dolphin sightings, we
believe it appropriate to take a precautionary approach to take
estimation use Year 2 sightings (7.09 individuals per day) as the basis
for a density value.
Common Dolphin
Common dolphins are present in the coastal waters outside of San
Diego Bay, but have typically been observed in the bay only
infrequently and were never seen during the Navy's surveys. However,
the previously described observations of common dolphins in the project
area during in 2014 prompted their inclusion in the second IHA, a
decision supported by increased observations of common dolphins during
Year 2. There have not been enough sightings of common dolphins in San
Diego Bay to develop a reliable estimate specific to the project area.
Sightings of long-beaked common dolphins are predominantly near shore,
and have been documented during Navy training exercises just offshore
and to the south of San Diego Bay, whereas those of short-beaked common
dolphins extend throughout the coastal and offshore waters. The NMSDD
provides an all-season density estimate of 0.1 animals/km\2\ for the
long-beaked common dolphin within southern California waters (derived
from Ferguson and Barlow [2003] and Barlow and Forney [2007]). However,
given the large numbers of dolphins and increasing observations during
2014-15, we use the sighting rate of 8.67 dolphins per day as the basis
for a density value. Although short-beaked common dolphins are less
common in nearshore waters than are long-beaked, and are expected to be
less likely to occur in the project area, we assign a single value to
all common dolphins that may occur in the project area. Any incidents
of take could be of either long-beaked or short-beaked common dolphins.
Pacific White-sided Dolphin
Pacific white-sided dolphins are not known from the project area,
but were observed in the bay on several occasions during Year 2
monitoring (0.28 individuals per day). This information produces a
density estimate slightly lower than that found in Hanser et al.
(2015), and is the only information available for use in estimating
potential exposures. However, this density value produces a zero
estimate for all scenarios. Based on 2014-15 observations in the
project area, this likely underrepresents the potential occurrence of
Pacific white-sided dolphins. Therefore, we assume that one group of
dolphins may occur in the relevant ZOI for each activity with a large
Level B ZOI (i.e., vibratory pile driving, vibratory pile removal, and
hydraulic pile cutting/diamond saw cutting). For each of these presumed
occurrences, we assume that it could be of the largest group size
observed by the Navy during 2014-15 project monitoring (i.e., seven).
Risso's Dolphin
Although no Risso's dolphins have not been observed in the project
area, they are one of the more common species known from deeper waters
nearby. Therefore, we use the regional density estimate from Hanser et
al. (2015) in estimating potential exposures.
Northern Elephant Seal
Only one elephant seal has been observed in the project area, but
given the increasing regional abundances for this species, we believe
it reasonable to propose take authorization, and the regional density
estimate found in Hanser et al. (2015) is used here. However, as for
Pacific white-sided dolphins, use of this density would produce a zero
exposure estimate for all scenarios, which likely underestimates
potential occurrence of this specie sin the project area. Therefore, we
assume that one elephant seal may occur in the relevant ZOI for each of
the three activity scenarios described above for Pacific white-sided
dolphin. It is unlikely that elephant seals would haul out on any
structures within the airborne ZOIs, and we do not consider harassment
via airborne noise as a possibility for this species.
[[Page 53132]]
Table 9--Calculations for Incidental Take Estimation
--------------------------------------------------------------------------------------------------------------------------------------------------------
Impact
Impact Vibratory Impact driving, Vibratory Pile Total proposed
Species Density driving, driving, driving, concrete/ removal cutting Airborne authorized takes (% of
steel \1\ steel concrete fiberglass total stock)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion............ 15.9201 372 540 22 33 540 2,352 10 3,497 (1.2)
Harbor seal.................... 0.4987 12 18 0 0 18 96 0 132 (0.4)
Bottlenose dolphin............. 1.2493 30 42 0 0 42 192 n/a 276 (55.2) \2\
Common dolphin................. 1.5277 36 54 0 0 54 240 n/a 348 (0.3 [LB]/0.1 [SB])
\3\
Gray whale..................... 0.115 0 6 0 0 6 0 n/a 12 (0.1)
Northern elephant seal \4\..... 0.0508 1 1 0 0 1 1 0 3 (0.002)
Pacific white-sided dolphin \5\ 0.0493 1 1 0 0 1 1 n/a 21 (0.04)
Risso's dolphin................ 0.2029 6 6 0 0 6 48 n/a 60 (1.0)
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ We assume that impact driving of steel piles would occur on the same day as vibratory driving of the same piles. Therefore, these estimates are
provided for reference only and are not included in the proposed total take authorization.
\2\ Total stock assumed to be 500 for purposes of calculation. See Table 3.
\3\ LB = long-beaked; SB = short-beaked.
\4\ Although the density calculation gives a result of zero for all scenarios, we assume one occurrence of one northern elephant seal will occur in the
relevant ZOI for each indicated activity.
\5\ Although the density calculation gives a result of zero for all scenarios, we assume one occurrence of a group of Pacific white-sided dolphins will
occur in the relevant ZOI for each indicated activity, with a group size of seven.
Analyses and Preliminary Determinations
Negligible Impact Analysis
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
Level B harassment 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 behavioral
harassment, we consider 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
the number and nature of estimated Level A harassment takes, the number
of estimated mortalities, and effects on habitat.
Pile driving 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 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. For example, use of
vibratory hammers does not have significant potential to cause injury
to marine mammals due to the relatively low source levels produced
(site-specific acoustic monitoring data show no source level
measurements above 180 dB rms) and the lack of potentially injurious
source characteristics. 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 one hundred 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 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, this negligible impact analysis is founded on the
following factors: (1) The possibility of injury, serious injury, or
mortality may reasonably be considered discountable; (2) the
anticipated incidents of Level B harassment consist of, at worst,
temporary modifications in behavior; (3) the absence of any significant
habitat within the project area, including
[[Page 53133]]
rookeries, significant haul-outs, or known areas or features of special
significance for foraging or reproduction; (4) the presumed efficacy of
the proposed mitigation measures in reducing the effects of the
specified activity to the level of least practicable impact. In
addition, these stocks are not listed under the ESA or considered
depleted under the MMPA. In combination, we believe that these factors,
as well as the available body of evidence from other similar
activities, demonstrate that the potential effects of the specified
activity will have only short-term effects on individuals. The
specified activity is not expected to impact rates of recruitment or
survival and will therefore not result in population-level impacts.
Based on the analysis contained herein of the likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the proposed monitoring and
mitigation measures, we preliminarily find that the total marine mammal
take from Navy's pier replacement activities will have a negligible
impact on the affected marine mammal species or stocks.
Small Numbers Analysis
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 likely effects of the
specified activity on marine mammals and their habitat, and taking into
consideration the implementation of the mitigation and monitoring
measures, we preliminarily find that small numbers of marine mammals
will be taken relative to the populations of the affected species or
stocks.
Impact on Availability of Affected Species for Taking for Subsistence
Uses
There are no relevant subsistence uses of marine mammals implicated
by this action. Therefore, we have 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)
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.
National Environmental Policy Act (NEPA)
In compliance with the National Environmental Policy Act of 1969
(42 U.S.C. 4321 et seq.), as implemented by the regulations published
by the Council on Environmental Quality (40 CFR parts 1500-1508), the
Navy prepared an Environmental Assessment (EA) to consider the direct,
indirect and cumulative effects to the human environment resulting from
the pier replacement project. NMFS made the Navy's EA available to the
public for review and comment, in relation to its suitability for
adoption by NMFS in order to assess the impacts to the human
environment of issuance of an IHA to the Navy. Also in compliance with
NEPA and the CEQ regulations, as well as NOAA Administrative Order 216-
6, NMFS has reviewed the Navy's EA, determined it to be sufficient, and
adopted that EA and signed a Finding of No Significant Impact (FONSI)
on July 8, 2013.
We have reviewed the Navy's application for a renewed IHA for
ongoing construction activities for 2015-16 and the 2014-15 monitoring
report. Based on that review, we have determined that the proposed
action is very similar to that considered in the previous IHAs. In
addition, no significant new circumstances or information relevant to
environmental concerns have been identified. Thus, we have determined
preliminarily that the preparation of a new or supplemental NEPA
document is not necessary, and will, after review of public comments
determine whether or not to reaffirm our 2013 FONSI. The 2013 NEPA
documents are available for review at www.nmfs.noaa.gov/pr/permits/incidental/construction.htm.
Proposed Authorization
As a result of these preliminary determinations, we propose 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. The proposed IHA language is
provided next.
This section contains a draft of the IHA itself. The wording
contained in this section is proposed for inclusion in the IHA (if
issued).
1. This Incidental Harassment Authorization (IHA) is valid for a
period of one year from the date of issuance.
2. This IHA is valid only for pile driving and removal activities
associated with the fuel pier replacement project in San Diego Bay,
California.
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 sp.), northern elephant seal (Mirounga angustirostris),
Pacific white-sided dolphin (Lagenorhynchus obliquidens), Risso's
dolphin (Grampus griseus), and gray whale (Eschrichtius robustus).
[[Page 53134]]
(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
------------------------------------------------------------------------
Harbor seal............................................. 137
California sea lion..................................... 3,519
Northern elephant seal.................................. 3
California coastal bottlenose dolphin................... 276
Pacific white-sided dolphin............................. 12
Risso's dolphin......................................... 60
Common dolphin.......................................... 348
Gray whale.............................................. 12
------------------------------------------------------------------------
(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.
(f) The Navy may conduct a maximum of 115 days of in-water impact
and vibratory pile driving and demolition (to include vibratory pile
removal, hydraulic pile cutting, and/or diamond saw cutting).
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 20 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--Minimum Radial Distance to Shutdown and Disturbance Zones
----------------------------------------------------------------------------------------------------------------
Distance to threshold in meters
Activity ---------------------------------------------------------------
190 dB 180 dB 160 dB 120 dB
----------------------------------------------------------------------------------------------------------------
Impact driving, steel piles..................... 150 450 2,000 n/a
Vibratory driving/removal, steel piles.......... 20 20 n/a 3,000
Impact driving, concrete piles.................. 20 20 505 n/a
Impact driving, concrete/fiberglass piles....... 20 20 259 n/a
Hydraulic cutting/diamond saw cutting........... 20 20 n/a 1,500
----------------------------------------------------------------------------------------------------------------
(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 establish monitoring locations as described
below. Please also refer to 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 be stationed at the active pile driving
rig in order to monitor the shutdown zones.
ii. For pile driving of 30-in steel piles, at least five additional
observers shall be positioned for optimal monitoring of the surrounding
waters. During impact driving of steel piles, one of these shall be
stationed for optimal monitoring of the cetacean Level A injury zone
(see Table 2), while others may be positioned at the discretion of the
Navy for optimal fulfillment of both acoustic monitoring objectives and
monitoring of the Level B harassment zone. During all other pile
driving, at least one additional observer shall be deployed and may be
positioned at the discretion of the Navy for optimal fulfillment of
both acoustic monitoring objectives and monitoring of the Level B
harassment zone.
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. Photographs
must be taken of any observed gray whales.
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 fifteen minutes have passed without re-detection of the animal.
(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 vibratory and impact pile driving. Soft start for vibratory drivers
requires contractors to initiate sound for fifteen seconds at reduced
energy followed by a thirty-second waiting period. This procedure is
repeated two additional times. 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
[[Page 53135]]
energy strike sets. Soft start shall be implemented at the start of
each day's pile driving and at any time following cessation of pile
driving for a period of thirty minutes or longer. Soft start for impact
drivers must be implemented at any time following cessation of impact
driving for a period of thirty 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 sixty days prior to the issuance of any subsequent IHA
for this project, whichever comes first. A final report shall be
prepared and submitted within thirty days following 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 (301-427-8425), NMFS, and
the West Coast Regional Stranding Coordinator (206-526-6550), 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.
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 27, 2015.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries
Service.
[FR Doc. 2015-21647 Filed 9-1-15; 8:45 am]
BILLING CODE 3510-22-P