[Federal Register Volume 78, Number 142 (Wednesday, July 24, 2013)]
[Notices]
[Pages 44539-44551]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2013-17760]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC622


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; issuance of an incidental harassment authorization.

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SUMMARY: In accordance with the regulations implementing the Marine 
Mammal Protection Act (MMPA) as amended, notification is hereby given 
that we have issued an incidental harassment authorization (IHA) to the 
U.S. Navy (Navy) to incidentally harass, by Level B harassment only, 
four species of marine mammals during construction activities 
associated with a pier replacement project in San Diego Bay, 
California.

[[Page 44540]]


DATES: This authorization is effective from September 1, 2013, through 
August 31, 2014.

ADDRESSES: A copy of the IHA and related documents may be obtained by 
visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm or by writing to Michael Payne, Chief, Permits and 
Conservation Division, Office of Protected Resources, National Marine 
Fisheries Service, 1315 East West Highway, Silver Spring, MD 20910. A 
memorandum describing our adoption of the Navy's Environmental 
Assessment (2013) and our associated Finding of No Significant Impact, 
prepared pursuant to the National Environmental Policy Act, are also 
available at the same site. Documents cited in this notice may also be 
viewed, by appointment, during regular business hours, at the 
aforementioned address.

FOR FURTHER INFORMATION CONTACT: Ben Laws, Office of Protected 
Resources, NMFS, (301) 427-8401.

SUPPLEMENTARY INFORMATION:

Background

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

    We received an application on September 24, 2012, from the Navy for 
the taking of marine mammals incidental to pile driving and removal in 
association with a pier replacement project in San Diego Bay at Naval 
Base Point Loma in San Diego, CA (NBPL). The Navy submitted a revised 
version of the application on November 15, 2013, which we deemed 
adequate and complete, and submitted additional revisions on December 
20, 2012, and April 22, 2013. The pier replacement project is a multi-
year project; this IHA would cover only the first year of the project, 
from September 1, 2013, through August 31, 2014. Four species of marine 
mammals are expected to occur in the vicinity of the project during all 
or a portion of the project duration: California sea lion (Zalophus 
californianus californianus), harbor seal (Phoca vitulina richardii), 
bottlenose dolphin (Tursiops truncatus truncatus), and gray whale 
(Eschrichtius robustus). California sea lions are present year-round 
and are common in the project area, while bottlenose dolphins may be 
present year-round but sightings are highly variable in Navy marine 
mammal surveys of northern San Diego Bay. Harbor seals have limited 
occurrence in the project area. Gray whales may be observed in San 
Diego Bay sporadically during migration periods.
    NBPL provides berthing and support services for Navy submarines and 
other fleet assets. The existing fuel pier serves as a fuel depot for 
loading and unloading tankers and Navy underway replenishment vessels 
that refuel ships at sea (``oilers''), as well as transferring fuel to 
local replenishment vessels and other small craft operating in San 
Diego Bay, and is the only active Navy fueling facility in southern 
California. Portions of the pier are over one hundred years old, while 
the newer segment was constructed in 1942. The pier as a whole is 
significantly past its design service life and does not meet current 
construction standards.
    Demolition and construction will occur in two phases to maintain 
the fueling capabilities of the existing fuel pier while the new pier 
is being constructed. The total duration of demolition/construction is 
estimated to be approximately four years (2013-17). During the first 
year of construction (the specified activity considered under this 
IHA), approximately 120 piles (including 18-in concrete and 36 to 48-in 
steel) will be installed and 109 piles will be removed (via multiple 
methods). All steel piles will be driven with a vibratory hammer for 
their initial embedment depths and finished with an impact hammer for 
proofing, as necessary.
    For pile driving activities, the Navy used NMFS-promulgated 
thresholds for assessing project impacts, outlined later in this 
document. The Navy used a site-specific model for transmission loss and 
empirically-measured source levels from other 36-72 in diameter pile 
driving events to estimate potential marine mammal exposures. Predicted 
exposures are outlined later in this document.

Description of the Specified Activity

    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). The specified activities with the potential to 
cause harassment of marine mammals within the waterways adjacent to 
NBPL, under the MMPA, are vibratory and impact pile driving and removal 
of piles via vibratory driver or pneumatic chipper associated with the 
pier replacement project and associated projects. The entire project is 
scheduled to occur from 2013-17; the specified activities for which 
incidental take is authorized by this IHA will occur for one year from 
September 1, 2013. Under the terms of a memorandum of understanding 
between the Navy and the U.S. Fish and Wildlife Service, 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. Therefore, all in-
water construction activities will occur during a window from 
approximately September 15 through April 1. Additional details 
regarding the specified geographic area and construction plans for the 
project were described in our Federal Register

[[Page 44541]]

notice of proposed authorization (78 FR 30873; May 23, 2013; hereafter, 
the FR notice); please see that document or the Navy's application for 
more information.
    The fuel pier replacement will consist of concurrent demolition of 
the old pier and construction of the new pier, such that fueling 
capabilities are maintained, as well as (1) temporary relocation of the 
Navy Marine Mammal Program (MMP); (2) temporary relocation of the 
Everingham Brothers San Diego Bay Bait Barge facility; and (3) dredging 
and sediment disposal. The bait barge facility is being moved during 
the project because it is a primary attractant of California sea lions 
to the project area and the relocation may be expected to reduce the 
number of sea lions exposed to noise levels constituting harassment 
under the MMPA. Dredging and sediment disposal are not considered to 
have significant impacts under the MMPA and are not considered as part 
of the specified activities described herein and in the FR notice. Pier 
demolition and construction and relocation of the MMP will require 
impact and vibratory pile driving. See Table 1-1 in the Navy's 
application for a complete construction phase summary.
    For the entire project, approximately 1,500 piles and caissons of 
various materials will be removed. There are multiple methods for pile 
removal, including dry pulling, cutting at the mudline, jetting, and 
vibratory removal. The majority of these methods do not produce 
significant levels of underwater sound; however, a vibratory hammer or 
pneumatic chipper may be required for certain piles. For the 
replacement pier structure, approximately 554 total piles will be 
installed, including steel and concrete piles of various sizes. For 
steel piles, vibratory driving is the preferred method of installation 
and will be used to drive the pile to refusal. The impact hammer may 
then be used for proofing or until the pile meets structural 
requirements. The concrete piles will first be jetted, a process 
wherein pressurized air or water jets are applied at the tip of the 
pile to loosen the substrate and allow the pile to sink vertically, 
before being driven the last few feet with the impact hammer. The 
fiberglass piles do not need to be embedded very deeply into the 
subsurface so will be impact-driven for the entire length. In all 
cases, impact driving will be minimized.
    Initial pile driving will be conducted as part of an Indicator Pile 
Program (IPP), designed to validate the length of pile required and the 
method of installation (vibratory and impact). Approximately twelve 
steel pipe piles (36- and 48-in diameter, exact mix to be determined 
later) will be driven in the new pier alignment to verify the driving 
conditions and establish the final driving lengths prior to fabrication 
of the final production piles that will be used to construct the new 
pier. In addition, the IPP will validate the acoustics modeling used by 
the Navy to estimate incidental take levels. Table 1-4 in the Navy's 
application summarizes the total piles that would be installed over the 
life of the project.
    The specified activity for the one-year period of this IHA includes 
pile driving associated with relocation of the MMP, pile driving 
associated with the IPP and construction of a temporary mooring 
dolphin, and beginning of construction of the new pier structure. In 
addition, pile removal associated with demolition of the old structure 
will begin. These activities are detailed in Table 1. The majority of 
pile removal will likely not require the use of vibratory extraction 
and/or pneumatic chipping, and these methods are included here as 
contingency in the event other methods of extraction are not 
successful.

                                  Table 1--Specified Activity Summary (2013-14)
----------------------------------------------------------------------------------------------------------------
                                                                                                         Number
                 Activity                          Timing (days)                   Pile type             piles
----------------------------------------------------------------------------------------------------------------
MMP relocation (at NMAWC)................  Sep-Oct 2013 (16)...........  18-in square concrete.......         50
Indicator Pile Program...................  Mar 2014 (17)...............  36- and 48-in steel pipe....         12
Temporary mooring dolphin................  Mar 2014 (5)................  36-in steel pipe............         16
Abutment pile driving....................  Mar-Apr 2014 (13)...........  48-in steel pipe............         24
Structural pile driving..................  Mar-Apr 2014 (15)...........  36- and 48-in steel pipe....         26
                                          ----------------------------------------------------------------------
    Total installed......................  ............................  ............................        128
----------------------------------------------------------------------------------------------------------------
Pile removal\1\..........................  Mar-Sep 2014................  16- and 24-in square                 18
                                                                          concrete.
Pile removal\1\..........................  Mar-Sep 2014................  12-in timber................         91
----------------------------------------------------------------------------------------------------------------
\1\ Pile removal schedule is notional and is dependent on contractor workload and timing of in-water work
  shutdown in spring 2014. Removals using no-impact methods (e.g., dry pull) may continue outside the in-water
  work window or would resume under the period of subsequent IHAs (i.e., September 2014).

    The analysis contained herein is based upon the specified work 
schedule. During the first year of work, approximately 66 non-
overlapping days of pile driving are expected to occur in the episodes 
described in Table 1. Approximately 84 days of demolition work are 
expected, beginning in March 2014. The majority of these 84 days will 
involve above-water work or other no-impact methods and will not impact 
marine mammals; the Navy assumes that approximately one quarter of the 
days (21 days) might involve methods that could cause disturbance to 
marine mammals.

Description of Sound Sources and Distances to Thresholds

    An in-depth description of sound sources in general was provided in 
the FR notice (78 FR 30873; May 23, 2013). Significant sound-producing 
in-water construction activities associated with the project include 
impact and vibratory pile driving and vibratory pile removal.
    NMFS uses 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 examine impacts to marine mammals from pile driving 
sounds from which empirical sound thresholds have been established. 
Current NMFS practice (in relation to the MMPA) regarding exposure of 
marine mammals to sound is that cetaceans and pinnipeds exposed to 
sound levels of 180 and 190 dB root mean square (rms; note that all 
underwater sound levels in this document are referenced to a pressure 
of 1 [micro]Pa) or above, respectively, are considered to have been 
taken by Level A (i.e., injurious) harassment, while behavioral 
harassment (Level B) is considered to have occurred when

[[Page 44542]]

marine mammals are exposed to sounds at or above 120 dB rms for 
continuous sound (such as will be produced by vibratory pile driving) 
and 160 dB rms for pulsed sound (produced by impact pile driving), but 
below injurious thresholds. For airborne sound, pinniped disturbance 
from haul-outs has been documented at 100 dB (unweighted) for pinnipeds 
in general, and at 90 dB (unweighted) for harbor seals (note that all 
airborne sound levels in this document are referenced to a pressure of 
20 [micro]Pa). NMFS uses these levels as guidelines to estimate when 
harassment may occur. NMFS is currently revising these acoustic 
guidelines. For more information on that process, please visit http://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.

Distance to Sound Thresholds

    Pile driving generates underwater noise that can potentially result 
in disturbance to marine mammals in the project area. Please see the FR 
notice (78 FR 30873; May 23, 2013) for a detailed description of the 
calculations and information used to estimate distances to relevant 
threshold levels. In general, the sound pressure level (SPL) at some 
distance away from the source (e.g., driven pile) is governed by a 
measured source level, minus the transmission loss of the energy as it 
dissipates with distance. Transmission loss--the decrease in acoustic 
intensity as an acoustic pressure wave propagates out from a source--
was modeled specifically for the project site on the basis of 
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. Because the model is specific to the project area around 
the fuel pier site, practical spreading loss was assumed in modeling 
sound propagation for pile driving at the relocation site for the Navy 
Marine Mammal Program facility. The practical spreading model follows a 
geometric propagation loss based on the distance from the pile, 
resulting in a 4.5 dB reduction in level for each doubling of distance 
from the source.
    The intensity of pile driving sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. Literature regarding 
SPLs recorded from pile driving projects is available for 
consideration. In order to determine reasonable SPLs and their 
associated effects on marine mammals that are likely to result from 
pile driving at NBPL, studies with similar properties to the proposed 
action were evaluated. Piles to be installed include 36- and 48-in 
steel pipe piles, 24- and 18-in concrete piles, and 16-in fiberglass-
concrete piles. In addition, a vibratory pile driver could be used in 
the extraction of 16-in steel, 14-, 16- and 24-in concrete, 13-in 
plastic, and 12-in timber piles. Sound levels associated with vibratory 
pile removal are assumed to be the same as those during vibratory 
installation (Reyff, 2007)--which is likely a conservative assumption--
and have been taken into consideration in the modeling analysis. 
Overall, studies which met the following parameters were considered: 
(1) Pile size and materials: Steel pipe piles (30-72 in diameter); (2) 
Hammer machinery: Vibratory and impact hammer; and (3) Physical 
environment: shallow depth (less than 100 ft [30 m]).
    Representative data for pile driving SPLs recorded from similar 
construction activities in recent years, as well as additional 
assumptions made in determining appropriate proxy values, were 
presented in the FR notice (78 FR 30873; May 23, 2013). Underwater 
sound levels from pile driving for this project are therefore assumed 
to be as follows:
     For 36- and 48-in steel pipes, 195 dB re 1 [mu]Pa (rms) at 
10 m when driven by impact hammer, 180 dB re 1 [mu]Pa (rms) at 10 m 
when driven by vibratory hammer;
     For 24-in concrete piles driven by impact hammer, 176 dB 
re 1 [mu]Pa (rms) at 10 m; and
     For 16- and 18-in concrete piles driven by impact hammer, 
173 dB re 1 [mu]Pa (rms) at 10 m.
     For vibratory removal of steel piles, 172 dB re 1 
[micro]Pa (rms) at 10 m; for vibratory removal/pneumatic chipping of 
non-steel piles, 160 dB re 1 [micro]Pa (rms) at 10 m.
    Based on these values and the results of site-specific transmission 
loss modeling, distances to relevant thresholds and associated areas of 
ensonification are presented in Table 2. Predicted distances to 
thresholds for different sources are shown in Figures 6-1 through 6-7 
of the Navy's application. The areas of ensonification reflect the 
conventional assumption that topographical features such as shorelines 
act as a barrier to underwater sound. Although it is known that there 
can be leakage or diffraction around such barriers, it is generally 
accepted practice to model underwater sound propagation from pile 
driving as continuing in a straight line past a shoreline projection 
such as Ballast Point. In contrast, although Zuniga Jetty would likely 
prevent sound propagation east of the jetty, this effect was not 
considered. Hence the projection of sound through the mouth of the bay 
into the open ocean would be truncated along the jetty and narrower in 
reality than shown. The limits of ensonification due to the project are 
assumed to be essentially the same for different pile sizes subject to 
vibratory installation or removal.

                   Table 2--Distances to Relevant Sound Thresholds and Areas of Ensonification
----------------------------------------------------------------------------------------------------------------
                                                         Distance to threshold (m) and associated area of
                                   Source level                       ensonification (km\2\)
           Description             (dB at 10 m)  ---------------------------------------------------------------
                                                      190 dB          180 dB          160 dB          120 dB
----------------------------------------------------------------------------------------------------------------
Steel piles, impact.............             195       36/0.0034      452/0.1477    5,484/8.5069             n/a
Steel piles, vibratory..........             180             n/a       14/0.0004             n/a   6,470/11.4895
24-in concrete piles............             176             n/a             n/a      505/0.1914             n/a
16-in concrete-fiberglass piles.             173             n/a             n/a      259/0.0834             n/a
18-in concrete piles\1\ (NMAWC).             173             n/a             n/a       84/0.0620             n/a
Vibratory extraction, steel.....             172             n/a             n/a             n/a   6,467/11.4895
Vibratory extraction/pneumatic               160             n/a             n/a             n/a   6,467/11.4890
 chipping, non-steel............
----------------------------------------------------------------------------------------------------------------
\1\ Practical spreading loss was assumed for pile driving at marine mammal relocation site because site-specific
  TL model used for sources at fuel pier is not applicable.


[[Page 44543]]

    Pile driving can generate airborne sound that could potentially 
result in disturbance to marine mammals (specifically, pinnipeds) which 
are hauled out or at the water's surface. As a result, the Navy 
analyzed the potential for pinnipeds hauled out or swimming at the 
surface near NBPL to be exposed to airborne SPLs that could result in 
Level B behavioral harassment. A spherical spreading loss model (i.e., 
6 dB reduction in sound level for each doubling of distance from the 
source), in which there is a perfectly unobstructed (free-field) 
environment not limited by depth or water surface, is appropriate for 
use with airborne sound and was used to estimate the distance to the 
airborne thresholds.
    As was discussed for underwater sound from pile driving, the 
intensity of pile driving sounds is greatly influenced by factors such 
as the type of piles, hammers, and the physical environment in which 
the activity takes place. In order to determine reasonable airborne 
SPLs and their associated effects on marine mammals that are likely to 
result from pile driving at NBPL, studies with similar properties to 
the Navy's project, as described previously, were evaluated.
    Based on in-situ recordings from similar construction activities, 
the Navy previously considered the maximum airborne sound levels that 
would result from impact and vibratory pile driving as 118 dB and 96 dB 
(at 15 m), respectively (Blackwell et al., 2004; Laughlin, 2010). The 
Navy has calculated the radial distances to the 90 and 100 dB airborne 
thresholds as 358 m and 113 m, respectively, for impact pile driving 
and 28 m and 9 m, respectively, for vibratory pile driving. The nearest 
known haul-out location for harbor seals is approximately 250 m distant 
from the notional pile driving location and hence would be subject to 
sound levels that may result in behavioral disturbance, if animals are 
present. For sea lions, all airborne distances are less than those 
calculated for underwater sound thresholds, therefore, protective 
measures would be in place out to the distances calculated for the 
underwater thresholds, and the distances for the airborne thresholds 
would be covered fully by mitigation and monitoring measures in place 
for underwater sound thresholds. No sea lion haul-outs or rookeries are 
located within the airborne harassment radii. However, we assume that 
any harbor seals present at the haul-out would likely flush into the 
water if harassed, and would therefore be subject to underwater sound. 
Similarly, pinnipeds in water that are within the area of 
ensonification for airborne sound could be incidentally taken by either 
underwater or airborne sound or both. Therefore, we consider any 
incidences of harassment from airborne sound to be accounted for in the 
take estimates for underwater sound.

Comments and Responses

    We published a notice of receipt of the Navy's application and 
proposed IHA in the Federal Register on May 23, 2013 (78 FR 30873). 
NMFS received comments from the Marine Mammal Commission (Commission), 
as well as a letter from the National Park Service. The Commission's 
comments and our responses are provided here, and the comments have 
been posted on the internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. We have determined that the mitigation measures 
described here will effect the least practicable impact on the species 
or stocks and their habitats.
    Comment 1: The Commission recommends that we require the Navy to 
use densities of 5.75 sea lions/km\2\ for summer and fall and 2.51 sea 
lions/km\2\ for winter and spring to re-estimate the number of sea 
lions that could be taken during the proposed activities.
    Response: The density values cited by the Commission are found in 
the Navy Marine Species Density Database (Hanser et al., 2012) and are 
derived from Navy surveys of San Diego Bay conducted from 2007-11 (n = 
11). The methodology for take estimation proposed by the Navy and 
employed here uses those same data, with an additional year of survey 
results (2007-12; n = 16). The primary difference, however, is that we 
attempt to produce the most realistic take estimate possible by 
approximating conditions expected to be in effect during the project. 
Specifically, only those survey results during the in-water work window 
(n = 13) and from the specific action area are used, and we attempt to 
quantify the effect of relocating the primary attractant for the 
population of California sea lions resident in the action area--the 
Everingham Brothers bait barges.
    During Navy surveys of the action area, an average abundance of 
approximately 63 California sea lions was observed (5.50 sea lions/
km\2\), but an average of approximately 50 of these individuals was 
observed to be on or near the bait barges. Therefore, we believe it 
appropriate to account for the relocation of this attractant outside of 
the action area and assume that approximately 13 individuals would be 
present in the action area (1.18 sea lions/km\2\). The bait barges, 
which are essentially floating pens filled with fish, provide a large 
haul-out area for sea lions but, importantly, they also provide a 
foraging opportunity. Therefore, while we recognize that the Commission 
has a valid point--that although the bait barges will be relocated 
outside the action area, some of the sea lions could still transit 
through the action area--we believe that the unique nature of the bait 
barges as both haul-out and de facto foraging hotspot for animals 
resident to San Diego Bay means that the majority of those individuals 
will remain in the vicinity of the bait barges. It would produce a 
grossly exaggerated estimate of take to ignore the relocation. Required 
marine mammal monitoring will determine whether this assumption is 
accurate or not and, if not, the approach to take estimation will be 
revised in future years of this project.
    Finally, the Commission points out that this approach produces a 
density estimate that is reduced by as much as a factor of five, 
depending on seasonality. For California sea lions, an increase in the 
currently authorized level of take (994 incidences) by a factor of five 
would not affect either our small numbers finding or our negligible 
impact determination. However, we believe the approach to take 
estimation described here to be appropriate to produce the most 
accurate estimate.
    Comment 2: The Commission recommends that we require the Navy to 
implement soft start procedures after 15 minutes if pile driving or 
removal is delayed or shut down because of the presence of a marine 
mammal within or approaching the shutdown zone.
    Response: We do not believe the recommendation would be effective 
in reducing the number or intensity of incidents of harassment--in 
fact, we believe that implementation of this recommendation may 
actually increase the number of incidents of harassment by extending 
the overall project duration--while imposing a high cost in terms of 
operational practicability. We note here that, while the Commission 
recommends use of the measure to avoid serious injury (i.e., injury 
that will result in death of the animal), such an outcome is extremely 
unlikely even in the absence of any mitigation measures (as described 
in the FR notice). Rather than disregard the recommendation as not 
germane, we address our response to the potential usefulness of the 
measure in avoidance of non-serious injury (i.e., Level A harassment).
    Soft start is required for the first impact pile driving of each 
day and, subsequently, after any impact pile driving stoppage of 30 
minutes or greater. The purpose of a soft start is to provide a 
``warning'' to animals by

[[Page 44544]]

initiating the production of underwater sound at lower levels than are 
produced at full operating power. This warning is presumed to allow 
animals the opportunity to move away from an unpleasant stimulus and to 
potentially reduce the intensity of behavioral reactions to noise or 
prevent injury of animals that may remain undetected in the zone 
ensonified to potentially injurious levels. However, soft start 
requires additional time, resulting in a larger temporal footprint for 
the project. That is, soft start requires a longer cumulative period of 
pile driving (i.e., hours) but, more importantly, leads to a longer 
overall duration (i.e., more days on which pile driving occurs). In 
order to maximize the effectiveness of soft start while minimizing the 
implementation costs, we require soft start after a period of extended 
and unobserved relative silence (i.e., at the beginning of the day, 
after the end of the required 30-minute post-activity monitoring 
period, or after 30 minutes with no impact driving). It is after these 
periods that marine mammals are more likely to closely approach the 
site (because it is relatively quiet) and less likely to be observed 
prior to initiation of the activity (because continuous monitoring has 
been interrupted).
    The Commission justifies this recommendation on the basis of the 
potential for undetected animals to remain in the shutdown zone, and 
describes various biases (i.e., availability, detection, and 
perception) on an observer's ability to detect an animal. We do not 
believe that time is a factor in determining the influence of these 
biases on the probability of observing an animal in the shutdown zone. 
That is, an observer is not more likely to detect the presence of an 
animal at the 15-minute mark of continuous monitoring than after 30 
minutes (it is established that soft start is required after any 
unmonitored period). Therefore, requiring soft start after 15 minutes 
(i.e., more soft starts) is not likely to result in increased avoidance 
of injury. Finally, we do not believe that the use of soft start may be 
expected to appreciably reduce the potential for injury where the 
probability of detection is high (e.g., small, shallow zones with good 
environmental conditions). Rather, the primary purpose of soft start 
under such conditions is to reduce the intensity of potential 
behavioral reactions to underwater sound in the disturbance zone.
    As noted by the Commission, there are multiple reasons why marine 
mammals may remain in a shutdown zone and yet be undetected by 
observers. Animals are missed because they are underwater (availability 
bias) or because they are available to be seen, but are missed by 
observers (perception and detection biases) (e.g., Marsh and Sinclair, 
1989). Negative bias on perception or detection of an available animal 
may result from environmental conditions, limitations inherent to the 
observation platform, or observer ability. While missed detections are 
possible in theory, this would require that an animal would either (a) 
remain submerged (i.e., be unavailable) for periods of time approaching 
or exceeding 15 minutes and/or (b) remain undetected while at the 
surface. We provide further site-specific detail below.
    First, environmental conditions in San Diego Bay are typically 
excellent and, unlike the moving aerial or vessel-based observation 
platforms for which detectability bias is often a concern, the 
observers here will be positioned in the most suitable locations to 
ensure high detectability (randomness of observations is not a concern, 
as it is for abundance sampling). We believe that the probability of 
detecting an animal within the 190 dB zone is 100 percent and, even in 
the larger 180 dB zone, we believe that under similar circumstances the 
appropriate monitoring strategy will allow detection of marine mammals. 
Biologists conducting Navy marine mammal surveys in the action area 
from 2007-12 believe that the detectability of animals within the study 
area at the time the surveys were conducted approached 100 percent. 
Regarding availability, the most abundant species, and therefore the 
species most likely to be present in the mitigation zones, are the 
California sea lion and bottlenose dolphin.
    It is extremely unlikely that a pinniped would remain within 
approximately 40 m (the radial distance to the shutdown zone for 
pinnipeds is 36 m) of a construction zone and area of high vessel 
traffic, in the absence of any known foraging opportunities or other 
attractant of any significance, for an extended period of time. 
However, in the event that such an unlikely situation occurred, the 
possibility that individuals would remain submerged for a period of 
time exceeding 15 minutes is discountable. Sea lions employ a shallow 
epipelagic foraging strategy, and numerous studies have reported mean 
dive times of approximately 2 minutes for California sea lions (e.g., 
Feldkamp et al., 1989 [mean dive time less than 3 min]; Weise et al., 
2006 [mean dive time 1.9  1.6 min]). Kuhn et al. (2003) 
cite published values for sea lion aerobic dive limits ranging from 
2.3-5.8 minutes and, while it is possible that sea lions may dive 
beyond these limits when foraging on the benthos, significantly longer 
dive durations would not be expected in shallow waters. In addition, 
while short surface intervals are also possible, longer values are 
typical of data found in the literature for animals engaged in foraging 
(e.g., Costa et al. (2007) report a mean surface interval of 1.6 
minutes). Sea lions will typically spend a much greater proportion of 
time at the surface when not foraging. Under the typically excellent 
observation conditions found in San Diego Bay, we believe that these 
surfaced animals would be observed.
    For bottlenose dolphins, a much greater proportion of time is 
typically spent submerged. However, dive intervals are also typically 
much shorter, meaning that surfacing occurs frequently. Mate et al. 
(1995) report a typical dive duration from another shallow bay (Tampa 
Bay) of only 25 seconds. Short dive duration coupled with a large 
average group size--approximately six during Navy surveys--means high 
availability and increased detectability. Based on the foregoing 
factors, we have high confidence in the ability of observers to detect 
marine mammals in the shutdown zones estimated for this project in San 
Diego Bay.
    Comment 3: The Commission recommends that we require the Navy to 
monitor the extent of the disturbance zone using additional shore- or 
vessel-based observers beyond the waterfront restricted area to (1) 
determine the numbers of marine mammals taken during pile driving and 
removal activities and (2) characterize the effects on them.
    Response: The Commission correctly notes that the proposed 
monitoring requirements for the proposed IHA did not specify the number 
or locations of observers. We have worked with the Navy to develop an 
appropriate monitoring strategy, as detailed in the Navy's Acoustic and 
Marine Mammal Monitoring Plan and now available at http://www.nmfs.noaa.gov/pr/permits/incidental.htm. In summary, at least one 
observer will be placed in the immediate vicinity of the active pile 
driving rig to observe the shutdown zones, while three additional 
observers will be placed on vessels at various locations throughout the 
action area to provide additional observation capability for the 
cetacean shutdown zone for impact driving and to monitor and record 
presence of marine mammals in the larger Level B harassment zone for 
vibratory pile driving. Only one observer will be required for 
monitoring

[[Page 44545]]

at the MMP relocation site, as the shutdown zones are the minimum 10 m 
and the 160 dB Level B harassment zone has a radial distance of only 84 
m. We agree with the Commission's recommendation and believe that the 
Monitoring Plan is sufficient to accomplish these objectives.

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 San Diego Bay, including the 
California sea lion, harbor seal, bottlenose dolphin, and gray whale. 
In addition, Pacific white-sided and common dolphins (Lagenorhynchus 
obliquidens and Delphinus sp., respectively) have been observed in 
nearshore coastal waters in the vicinity, but have no known occurrence 
in San Diego Bay or near the project area. None of these species are 
listed under the Endangered Species Act (ESA). The FR notice (78 FR 
30873; May 23, 2013) summarizes the population status and abundance of 
these species, and the Navy's application provides detailed life 
history information.

Potential Effects of the Specified Activity on Marine Mammals

    We have determined that pile driving, as outlined in the project 
description, has the potential to result in behavioral harassment of 
marine mammals that may be present in the project vicinity while 
construction activity is being conducted. Pile driving could 
potentially harass those pinnipeds that are in the water close to the 
project site, whether exposed to airborne or underwater sound. The FR 
notice (78 FR 30873; May 23, 2013) provides a detailed description of 
marine mammal hearing and of the potential effects of these 
construction activities on marine mammals.

Anticipated Effects on Habitat

    The specified activities at NBPL will not result in permanent 
impacts to habitats used directly by marine mammals, such as haul-out 
sites, but may have potential short-term impacts to food sources such 
as forage fish. There are no rookeries or major haul-out sites nearby 
(the bait barges will be relocated from the project area), foraging 
hotspots, or other ocean bottom structure of significant biological 
importance to marine mammals that may be present in the marine waters 
in the vicinity of the project area. Therefore, the main impact issue 
associated with the specified activity will be temporarily elevated 
sound levels and the associated direct effects on marine mammals. The 
most likely impact to marine mammal habitat occurs from pile driving 
effects on likely marine mammal prey (i.e., fish) near NBPL and minor 
impacts to the immediate substrate during installation and removal of 
piles during the pier replacement project. The FR notice (78 FR 30873; 
May 23, 2013) describes these potential impacts in greater detail.

Mitigation

    In order to issue an incidental take authorization (ITA) under 
section 101(a)(5)(D) of the MMPA, we 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 (where relevant).
    Proxy source measurements and site-specific modeling of spreading 
loss (with the exception of the MMP relocation site, where practical 
spreading loss was assumed) were 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 zones that will be 
established around each pile to prevent Level A harassment to marine 
mammals, while providing estimates of the areas within which Level B 
harassment might occur. In addition to the measures described later in 
this section, the Navy will employ the following standard mitigation 
measures:
    (a) Conduct briefings between construction supervisors and crews, 
marine mammal monitoring team, acoustical 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.
    (b) Comply with applicable equipment sound standards and ensure 
that all construction equipment has sound control devices no less 
effective than those provided on the original equipment.
    (c) For in-water heavy machinery work with the potential to affect 
marine mammals (other than pile driving), if a marine mammal comes 
within 10 m, operations shall cease and vessels shall reduce speed to 
the minimum level required to maintain steerage and safe working 
conditions. This type of work could include the following activities: 
(1) movement of the barge to the pile location and (2) removal of the 
pile from the water column/substrate via a crane (i.e., deadpull). For 
these activities, monitoring will take place from 15 minutes prior to 
initiation until the action is complete.

Monitoring and Shutdown for Pile Driving

    The following measures will 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, serious injury, or death of marine mammals. Radial 
distances for shutdown zones are shown in Table 2. For certain pile 
types or techniques, the shutdown zone would not exist because source 
levels are lower than the threshold (see Table 2). However, a minimum 
shutdown zone of 10 m will be established during all pile driving and 
removal activities, regardless of the estimated zone. These 
precautionary measures are intended to prevent the already unlikely 
possibility of physical interaction with construction equipment and to 
further reduce any possibility of acoustic injury.
    Disturbance Zone--Disturbance zones are typically defined as the 
area in which SPLs equal or exceed 160 or 120 dB rms (for pulsed or 
non-pulsed sound, respectively). Disturbance zones provide utility for 
monitoring conducted for mitigation purposes (i.e., shutdown zone 
monitoring) by establishing monitoring protocols for areas adjacent to 
the shutdown zones. Monitoring of disturbance zones enables observers 
to be aware of and communicate the presence of marine mammals in the 
project area but outside the shutdown zone and thus prepare for 
potential shutdowns of activity. However, the primary purpose of 
disturbance zone monitoring is for documenting incidents of Level B 
harassment; disturbance zone monitoring is discussed in greater detail 
later (see ``Monitoring and Reporting''). Nominal radial distances for 
disturbance zones are shown in Table 2. As with any such large action 
area, it is impossible to guarantee that all animals will be observed 
or to make

[[Page 44546]]

comprehensive observations of fine-scale behavioral reactions to sound.
    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. That 
information may then be used to extrapolate observed takes to reach an 
approximate understanding of actual total takes.
    Monitoring Protocols--Monitoring will be conducted before, during, 
and after pile driving activities. In addition, observers shall record 
all incidences 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. Please see the Acoustic and Marine Mammal Monitoring Plan 
(available at http://www.nmfs.noaa.gov/pr/permits/incidental.htm), 
developed by the Navy in agreement with NMFS, for full details of the 
monitoring protocols. Monitoring will take place from 15 minutes prior 
to initiation through 30 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 30 minutes.
    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 
Navy's 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, wildlife 
management, mammalogy, or related fields (bachelor's 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 15 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 will 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 15 minutes have passed 
without re-detection of the animal. Monitoring will be conducted 
throughout the time required to drive a pile.

Timing Restrictions

    The Navy has set timing restrictions for pile driving activities to 
avoid in-water work when least tern populations are most likely to be 
foraging and nesting. The in-water work window for avoiding negative 
impacts to terns is September 16-March 31. All pile driving will be 
conducted only during daylight hours.

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 vibratory hammers for 
fifteen seconds at reduced energy followed by a 30-second waiting 
period. This procedure is repeated two additional times. However, 
implementation of soft start for vibratory pile driving during previous 
pile driving work conducted by the Navy at another location has led to 
equipment failure and serious human safety concerns. Therefore, 
although vibratory soft start was proposed for implementation in the FR 
notice (78 FR 30873; May 23, 2013), it is not required as a mitigation 
measure for this project, as we have determined it not to be 
practicable. We have further determined this measure unnecessary to 
providing the means of effecting the least practicable impact on marine 
mammals and their habitat. For impact driving, soft start will be 
required, and contractors will provide an initial set of three strikes 
from the impact hammer at 40 percent energy, followed by a 30-second 
waiting period, then two subsequent three strike sets.
    We have carefully evaluated the applicant's mitigation measures and 
considered a range of other measures in the context of ensuring that we 
prescribe the means of effecting 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

[[Page 44547]]

likely efficacy of the specific measure to minimize adverse impacts as 
planned; and (3) the practicability of the measure for applicant 
implementation, including consideration of personnel safety, and 
practicality of implementation.
    Based on our evaluation of the applicant's planned measures, as 
well as any other potential measures that may be relevant to the 
specified activity, we have determined that these 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.

Monitoring and Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that we 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 ITAs 
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. 
Please see the Navy's Acoustic and Marine Mammal Monitoring Plan for 
full details of the requirements for monitoring and reporting. We have 
determined that this monitoring plan, which is summarized here, is 
sufficient to meet the MMPA's monitoring and reporting requirements.

Acoustic Measurements

    The primary purpose of acoustic monitoring is to empirically verify 
modeled injury and behavioral disturbance zones for marine mammals. The 
Navy will determine actual distances to the 160-, 180-, and 190-dB 
zones for underwater sound (where applicable) and to the 90- and 100-dB 
zones for airborne sound. For non-pulsed sound, distances will be 
determined for attenuation to the greater of either the 120-dB 
threshold or to the point at which sound becomes indistinguishable from 
background levels. Acoustic monitoring will be conducted with the 
following objectives:
    (a) Indicator Pile Program (IPP)--Implement a robust in-situ 
monitoring effort to measure sound pressure levels from different 
project activities, including impact and vibratory driving of 36- and 
48-in piles, and to validate the Navy's site-specific transmission loss 
modeling effort.
    (b) Conduct acoustic monitoring for vibratory pile extraction and 
for pneumatic chipping, if used.
    (c) Continue the Navy's collection of ambient underwater sound 
measurements in the absence of project activities to develop a rigorous 
baseline for the San Diego Bay region.
    It is assumed that the measured contours will be significantly 
reduced compared to the conservatively modeled ZOIs. As statistically 
robust results from acoustic monitoring become available, marine mammal 
mitigation zones will be revised as necessary to encompass actual ZOIs 
in subsequent years of the fuel pier replacement project. However, 
should substantial discrepancies become evident through limited data 
processing, the Navy will contact NMFS to propose and discuss 
appropriate changes in monitoring protocols. Acoustic monitoring will 
be conducted in accordance with the approved Acoustic and Marine Mammal 
Monitoring Plan developed by the Navy. Notional monitoring locations 
are shown in Figures 3-1 and 3-2 of the Navy's Plan. Please see that 
plan, available at http://www.nmfs.noaa.gov/pr/permits/incidental.htm, 
for full details of the required acoustic monitoring.
    Some details of the methodology include:
     Hydroacoustic monitoring will be conducted for each 
different type of pile and each different method of installation and 
removal. Monitoring will occur across a representative range of 
locations with special attention given to the 120-, 160-, 180-, and 
190-dB ZOI contours. The resulting data set will be analyzed to provide 
a statistically robust characterization of the sound source levels and 
transmission loss associated with different types of pile driving and 
removal activities.
     For underwater recordings, hydrophone systems with the 
ability to measure real time SPLs will be used in accordance with NMFS' 
most recent 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 
50 ft (15.2 m) from the source via a sound meter with integrated 
microphone placed on a tripod 5 ft above the ground. Other distances 
may also be utilized to obtain better data if the signal cannot be 
isolated clearly due to other sound sources (i.e., barges or 
generators). If from a distance other than 50 ft, the source data would 
be converted to the 50-ft distance based on simple spherical spreading.
     Hydrophones will be placed 10 m from the source and within 
the ZOIs to their predicted eastern and southern limits. An integrated 
DGPS will record the location of individual acoustic records. A depth 
sounder or weighted tape measure will be used to determine the depth of 
the water. The hydrophone will be attached to a weighted line to 
maintain a constant depth.
     Each hydrophone (underwater) and microphone (airborne) 
will be calibrated at the beginning of each day of monitoring activity. 
Pressure and intensity levels will be reported relative to 1 [mu]Pa and 
1 [mu]Pa\2\, respectively.
     For each monitored location, a hydrophone will be deployed 
at mid-depth in order to evaluate site specific attenuation and 
propagation characteristics.
     In order to determine the area encompassed by the relevant 
isopleths for marine mammals, hydrophones will collect data at various 
distances from the source to measure attenuation throughout the ZOIs.
     Ambient conditions, both airborne and underwater, will be 
measured at the same monitoring locations but in the absence of project 
sound to determine background sound levels. Ambient levels are intended 
to be recorded over the frequency range from 7 Hz to 20 kHz. Ambient 
conditions will be recorded for at least one minute every hour of the 
work day, for at least one week of each month of the period of the IHA.
     Sound levels associated with soft-start techniques will 
also be measured but will be differentiated from source level 
measurements.
     Airborne levels will be recorded as unweighted as well as 
in dBA, and the distance to marine mammal injury and behavioral 
disturbance thresholds, also referred to as shutdown and buffer zones, 
would be measured.
     Environmental data will 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, etc.).

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

[[Page 44548]]

conducting monitoring. The Navy will monitor the shutdown zone and 
disturbance zone before, during, and after pile driving as described 
under ``Mitigation'' and in the Acoustic and Marine Mammal Monitoring 
Plan. Notional monitoring locations are shown in Figures 3-1 and 3-2 of 
the Navy's Plan. Please see that plan, available at http://www.nmfs.noaa.gov/pr/permits/incidental.htm, for full details of the 
required marine mammal monitoring. Based on our requirements, the Plan 
includes 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 will 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.
    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 incidences of take. We require that, at a minimum, the 
following information be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel, and if possible, 
the correlation to SPLs;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.
    In addition, photographs will be taken of any gray whales observed. 
These photographs will be submitted to NMFS' Southwest Regional Office 
for comparison with photo-identification catalogs to determine whether 
the whale is a member of the western North Pacific population.

Reporting

    A draft report must be submitted to NMFS within 45 calendar days of 
the completion of acoustic measurements and marine mammal monitoring. 
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 adverse responses to construction 
activities by marine mammals and a complete description of all 
mitigation shutdowns and the results of those actions and a refined 
take estimate based on the number of marine mammals observed during the 
course of construction. A final report must be submitted within 30 days 
following resolution of comments on the draft report. Required contents 
of the monitoring reports are described in more detail in the Navy's 
Acoustic and Marine Mammal Monitoring Plan.

Estimated Take by Incidental Harassment

    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 will be by Level B harassment, involving 
temporary changes in behavior. The planned mitigation and monitoring 
measures are expected to minimize the possibility of injurious or 
lethal takes such that take by Level A harassment, serious injury or 
mortality is considered discountable. However, it is unlikely that 
injurious or lethal takes would occur even in the absence of the 
planned mitigation and monitoring measures.
    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 (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. This 
practice potentially overestimates the numbers of marine mammals taken.
    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). The 
occurrence of California sea lions in the project area, and, therefore, 
the likely incidence of exposure of sea lions to sound levels above 
relevant thresholds, will be much reduced due to the relocation of the 
bait barges (i.e., significant California sea lion haul-outs). 
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, and gray whales in San Diego Bay that may result from pile 
driving during construction activities associated with the fuel pier 
replacement project described previously in this document.

Marine Mammal Densities

    For all species, the best scientific information available was used 
to construct density estimates or estimate local abundance. Although 
information exists for regional offshore surveys for marine mammals, it 
is unlikely that these data would be representative of

[[Page 44549]]

the fauna that may be encountered in San Diego Bay. As a result, the 
data resulting from dedicated line-transect surveys conducted by the 
Navy from 2007-12, or from opportunistic observations for more rarely 
observed species, was deemed most appropriate for use in estimating the 
number of incidental harassments that may occur as a result of the 
specified activities (see Figures 3-1 and 3-2 of the Navy's 
application). Boat survey transects established within northern San 
Diego Bay in 2007 have been resurveyed on 16 occasions, 13 of which 
were during the seasonal window for in-water construction and 
demolition (September-April).

Description of Take Calculation

    The take calculations presented here rely on the best data 
currently available for marine mammal populations in San Diego Bay. The 
methodology for estimating take was described in detail in the FR 
notice (78 FR 30873; May 23, 2013). The ZOI impact area is the 
estimated range of impact to the sound criteria. The distances (actual) 
specified in Table 2 were used to calculate ZOI around each pile. The 
ZOI impact area took into consideration the possible affected area of 
San Diego Bay with attenuation due to land shadowing from bends in the 
shoreline. Because of the close proximity of some of the piles to the 
shore, the ZOIs for each threshold are not necessarily spherical and 
may be truncated.
    While pile driving can occur any day throughout the in-water work 
window, and the analysis is conducted on a per day basis, only a 
fraction of that time is actually spent pile driving. The exposure 
assessment methodology is an estimate of the numbers of individuals 
exposed to the effects of pile driving activities exceeding NMFS-
established thresholds. Of note in these exposure estimates, mitigation 
methods (i.e., visual monitoring and the use of shutdown zones) were 
not quantified within the assessment and successful implementation of 
mitigation is not reflected in exposure estimates. For the reasons 
noted above, results from this acoustic exposure assessment likely 
overestimate take estimates to some degree.
    Airborne Sound--No incidents of incidental take resulting solely 
from airborne sound are expected. Distances to the harassment 
thresholds are generally not expected to reach areas where pinnipeds 
may haul out (but see below regarding harbor seals). We recognize that 
pinnipeds in the water could be exposed to airborne sound that may 
result in behavioral harassment when looking with heads above water. 
However, these animals would previously have been incidentally taken as 
a result of exposure to underwater sound above the behavioral 
harassment thresholds, which are in all cases larger than those 
associated with airborne sound. Thus, the behavioral harassment of 
these animals is already accounted for in these estimates of potential 
take. Multiple incidents of exposure to sound above NMFS' thresholds 
for behavioral harassment are not believed to result in increased 
behavioral disturbance, in either nature or intensity of disturbance 
reaction. Therefore, we do not believe that authorization of incidental 
take resulting from airborne sound for pinnipeds is warranted.
    In the proposal for this IHA, because the nearest known haul-out 
location for harbor seals is approximately 250 m from the fuel pier and 
within the largest airborne ZOI, we did assume that individuals present 
could be incidentally taken by both underwater and airborne sound on 
each day. However, we have determined that this is not likely and is 
inconsistent with our past practice with regard to the potential for 
incidental taking by airborne sound. Because few harbor seals are 
likely to be present, and harbor seals readily flush from haul-outs in 
the presence of harassing stimuli, we believe that any harbor seals 
present at the haul-out would likely be exposed to potentially 
harassing levels of underwater sound in addition to the airborne sound. 
Therefore, our take proposal for harbor seals was an overestimate and 
double-counted potential incidences of harbor seal take.
    The derivation of density or abundance estimates for each species, 
as well as further description of the rationale for each take estimate, 
was described in detail in the FR notice (78 FR 30873; May 23, 2013). A 
summary of the information and assumptions that went into take 
estimates for each species is provided here. Total take estimates are 
presented in Table 3.
     California sea lion--For California sea lions, the most 
common species in northern San Diego Bay and the only species with 
regular occurrence in the project area, it was determined that the 
density value derived from site-specific surveys would be most 
appropriate for use in estimating potential incidences of take. 
Corrected survey data indicate an average abundance in the project area 
of 63 individuals; however, an average of 47 animals was observed on or 
swimming next to the bait barges. Assuming the same proportion of the 
population continues to congregate at the bait barges when they are 
relocated, there would be an average of approximately 13 individuals 
within the ZOI without the bait barges' influence as a sea lion 
aggregator.
     Bottlenose dolphin--Given the sporadic nature of 
bottlenose dolphin sightings and their high variability in terms of 
numbers and locations, the regional density estimate of 0.36/km\2\ 
developed for the NMSDD (Hanser et al., 2012) was considered a more 
reliable indicator than the results of site-specific surveys of the 
number of bottlenose dolphins that may be present and is used here to 
estimate the potential number of incidences of take.
     Harbor seal--Harbor seal presence in the project area is 
assessed on the basis of the only observational data available, the 
opportunistic observation of several individuals occurring in the 
vicinity of Pier 122 repeatedly for a period of about a month. We 
therefore assume that as many as three harbor seals could be 
incidentally harassed on a daily basis for as much as one month.
     Gray whale--On the basis of limited information, we assume 
here that 15 exposures of gray whales to sound that could result in 
harassment might occur. This could result from as many as 15 
individuals transiting near the mouth of the Bay, or from one 
individual entering the Bay and lingering in the project area for 15 
days. We limit the time period to 15 days because, although both of 
these scenarios are unlikely, they would only possibly occur in March. 
Most sightings of gray whales near or within the Bay have been outside 
of the in-water work window.
    Steel pile installation involves a combination of vibratory and 
impact hammering. Both are assumed to occur on the same day and, 
therefore, the estimated number of animals taken is given by the 
maximum of either type of exposure. Given that the vibratory (120 dB 
rms) ZOI is larger, all animals considered behaviorally harassed by 
impact pile driving are also considered to potentially be harassed by 
vibratory pile driving, whereas animals outside of the ZOI for impact 
hammering but within the ZOI for vibratory hammering would only be 
harassed by the latter. For example, for California sea lions the 
estimate for vibratory pile driving is 700 and the estimate for impact 
pile driving is 500. Because both events occur on the same day and the 
vibratory harassment zone subsumes the impact harassment zone, the 
estimate for vibratory pile driving necessarily includes the 500 
incidents of harassment estimated for impact pile driving alone. To 
provide a more conservative estimate of total harassments, demolition 
use of vibratory extraction is assumed not to

[[Page 44550]]

overlap the driving of steel piles for the new pier. Thus, the 294 
incidences of harassment for California sea lions resulting from pile 
removal would add to the 700 estimated for pile installation (500 
resulting from either vibratory or impact installation and 200 
resulting from vibratory installation alone) for a total estimate of 
994 incidences of harassment.

                         Table 3--Number of Potential Incidental Takes of Marine Mammals within Various Acoustic Threshold Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                    Underwater                               Airborne
                                                         --------------------------------------------------------------------------------
                                                                            Disturbance
                                              Density                       threshold,       Vibratory       Vibratory        Impact           Total
                 Species                    (/    Impact injury     combined         injury        disturbance     disturbance     authorized
                                              km\2\)         threshold        impact/     threshold (180/ threshold (120  threshold  (90/      takes
                                                           (180/190 dB)      vibratory        190 dB)           dB)           100 dB)
                                                                           (160 dB) \1\
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion.....................            1.18               0             500               0             494               0             994
Harbor seal \2\.........................             n/a               0              90               0               0          \3\ 90              90
Gray whale \2\..........................             n/a               0              15               0               0             N/A              15
Bottlenose dolphin......................            0.36               0             144               0             163             N/A             307
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ The 160-dB acoustic harassment zone associated with impact pile driving will always be subsumed by the 120-dB harassment zone produced by vibratory
  driving. Therefore, total takes estimated for impact driving alone could occur as a result of either impact or vibratory driving.
\2\ Because there is no density estimate available for harbor seals or gray whales, we cannot estimate takes separately for vibratory and impact pile
  driving. We simply assume here that these animals could be present within the project area for 30 (3 harbor seals) or 15 days (1 gray whale),
  respectively, and that they could be taken by impact or vibratory driving or vibratory removal. We also assume that mitigation measures would be
  effective in preventing Level A harassment for these species and believe a zero value for Level A harassments to be reasonable.
\3\ Although the assumed harbor seal haul-out location is within the airborne ZOI, we believe that these individuals would likely flush or enter the
  water on their own during the course of a 24-hr period and be exposed to underwater sound. Therefore, only one incidence of taking per animal per day
  is considered under total authorized takes.

Negligible Impact and Small Numbers Analysis and Determinations

    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.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
the number of anticipated mortalities; (2) the number and nature of 
anticipated injuries; (3) the number, nature, intensity, and duration 
of Level B harassment; and (4) the context in which the take occurs.

Small Numbers Analysis

    The numbers of animals authorized to be taken for California sea 
lions, harbor seals, and gray whales would be considered small relative 
to the relevant stocks or populations (each less than one percent) even 
if each estimated taking occurred to a new individual--an extremely 
unlikely scenario. However, for animals occurring in northern San Diego 
Bay, there will almost certainly be some overlap in individuals present 
day-to-day and, for harbor seals and gray whales, the estimates are 
explicitly assumed to represent repeated incidental taking of the same 
individuals (three harbor seals and one gray whale).
    The number of authorized takes for bottlenose dolphins is higher 
relative to the total stock abundance estimate. However, these numbers 
represent the estimated incidences 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 harassed by project 
activities. California coastal bottlenose dolphins range from San 
Francisco Bay to San Diego (and south into Mexico) and the specified 
activity will be stationary within an enclosed bay 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 incidences of take represent small numbers of 
bottlenose dolphins.

Negligible Impact Analysis

    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 airborne or 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 
methods of installation and measures designed to minimize the 
possibility of injury to marine mammals. The potential for these 
outcomes is minimized through the construction method and the 
implementation of the planned mitigation measures. Specifically, 
vibratory hammers will be the primary method of installation, and this 
activity does not have significant potential to cause injury to marine 
mammals due to the relatively low source levels produced (less than 190 
dB) 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 (use of a sound attenuation 
system, which reduces overall source levels as well as dampening the 
sharp, potentially injurious peaks, and implementation of shutdown 
zones) significantly reduce any possibility of injury. Likewise, Level 
B harassment will be reduced to the level of least practicable adverse 
impact through the use of mitigation measures described herein that, 
given sufficient ``notice'' through mitigation measures including 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, and the likelihood that marine mammal detection ability by 
trained observers is high under the

[[Page 44551]]

environmental conditions described for San Diego Bay, enabling 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 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). 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. The pile driving activities analyzed here are similar to 
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 viability for California coastal bottlenose 
dolphins, and thus would not result in any adverse impact to the stock 
as a whole. For pinnipeds, no rookeries are present in the project 
area, there are no haul-outs other than those provided 
opportunistically by man-made objects (the primary such haul-out, the 
bait barges, will be relocated away from the project area), and the 
project area is not known to provide foraging habitat of any special 
importance.
    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 incidences of Level B harassment consist of, at worst, 
temporary modifications in behavior; (3) the absence of any major 
rookeries and only a few isolated and opportunistic haul-out areas near 
or adjacent to the project site; (4) the absence of any other known 
areas or features of special significance for foraging or reproduction 
within the project area; (5) the presumed efficacy of the planned 
mitigation measures in reducing the effects of the specified activity 
to the level of least practicable impact. In addition, none of these 
stocks are listed under the ESA or considered of special status (e.g., 
depleted or strategic) under the MMPA. California sea lions and harbor 
seals (in California) are thought to have reached or to be approaching 
carrying capacity, while gray whales are thought to be increasing. The 
California coastal stock of bottlenose dolphins remained stable during 
the most recent period of trend analysis. 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.

Determinations

    The number of marine mammals actually incidentally harassed by the 
project will depend on the distribution and abundance of marine mammals 
in the vicinity of the survey activity. However, we find that the 
number of potential takings authorized (by level B harassment only), 
which we consider to be a conservative, maximum estimate, is small 
relative to the relevant regional stock or population numbers, and that 
the effect of the activity will be mitigated to the level of least 
practicable impact through implementation of the mitigation and 
monitoring measures described previously. Based on the analysis 
contained herein of the likely effects of the specified activity on 
marine mammals and their habitat, we find that the total taking from 
the activity will have a negligible impact on the affected species or 
stocks.

Impact on Availability of Affected Species or Stock for Taking for 
Subsistence Uses

    There are no relevant subsistence uses of marine mammals implicated 
by this action.

Endangered Species Act (ESA)

    The Navy initiated informal consultation under section 7 of the ESA 
with NMFS' Southwest 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, western North Pacific gray whales. The Navy has 
not requested authorization of the incidental take of WNP gray whales 
and no such authorization is issued. 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. The Navy's EA and NMFS' FONSI for this action may be 
found at http://www.nmfs.noaa.gov/pr/permits/incidental.htm.

Authorization

    As a result of these determinations, we have issued an IHA to the 
Navy to conduct the specified activities in San Diego Bay for one year, 
from September 1, 2013, through August 31, 2014, provided the 
previously described mitigation, monitoring, and reporting requirements 
are incorporated.

    Dated: July 19, 2012.
Helen M. Golde,
Deputy Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2013-17760 Filed 7-23-13; 8:45 am]
BILLING CODE 3510-22-P