Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Wharf Construction Project, 43148-43165 [2013-17404]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 78, Number 139 (Friday, July 19, 2013)]
[Notices]
[Pages 43148-43165]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-17404]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC646


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Wharf Construction 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, 
six species of marine mammals during construction activities associated 
with a wharf construction project in Hood Canal, Washington.

DATES: This authorization is effective from July 16, 2013, through 
February 15, 2014.

ADDRESSES: A copy of the IHA and related documents may be obtained by 
visiting the internet at: https://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 Impact 
Statement (2011) and our associated Record of Decision, 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].''

[[Page 43149]]

Summary of Request

    We received an application on December 10, 2012, from the Navy for 
the taking of marine mammals incidental to pile driving and removal in 
association with a wharf construction project in the Hood Canal at 
Naval Base Kitsap in Bangor, WA (NBKB). The Navy submitted a revised 
version of the application on May 6, 2013, which we deemed adequate and 
complete. The wharf construction project is a multi-year project; this 
IHA would cover only the second year of the project, from July 16, 
2013, through February 15, 2014. We previously issued an IHA to the 
Navy for the first year of work associated with this project; that IHA 
was valid from July 16, 2012, through February 15, 2013 (77 FR 42279; 
July 18, 2012). Pile driving and removal activities in a given year may 
occur only within an approved in-water work window from July 16-
February 15. Six species of marine mammals may be affected by the 
specified activities: Steller sea lion (Eumetopias jubatus 
monteriensis), California sea lion (Zalophus californianus 
californianus), harbor seal (Phoca vitulina richardii), killer whale 
(transient only; Orcinus orca), Dall's porpoise (Phocoenoides dalli 
dalli), and harbor porpoise (Phocoena phocoena vomerina). These species 
may occur year-round in the Hood Canal, with the exception of the 
Steller sea lion, which is typically present only from fall to late 
spring (October to mid-April), and the California sea lion, which is 
typically present from late summer to late spring (August to early 
June). The killer whale and Dall's porpoise have been observed in Hood 
Canal but do not regularly occur there.
    NBKB provides berthing and support services to Navy submarines and 
other fleet assets. The Navy plans to continue construction of the 
Explosive Handling Wharf 2 (EHW-2) facility at NBKB in order 
to support future program requirements for submarines berthed at NBKB. 
The Navy has determined that construction of EHW-2 is necessary because 
the existing EHW alone will not be able to support future program 
requirements. Under the specified activities--which include only the 
portion of the project that would be completed under this 1-year IHA--a 
maximum of 195 pile driving days would occur. All piles will be driven 
with a vibratory hammer for their initial embedment depths, while 
select piles may be finished with an impact hammer for proofing, 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. Sound attenuation measures (i.e., bubble curtain) will be 
used during all impact hammer operations.
    For pile driving activities, the Navy used thresholds recommended 
by NMFS for assessing project impacts, outlined later in this document. 
The Navy assumed practical spreading loss and used empirically-measured 
source levels from other similar pile driving events to estimate 
potential marine mammal exposures. Predicted exposures are outlined 
later in this document. The calculations predict that only Level B 
harassment will occur associated with pile driving or construction 
activities.

Description of the Specified Activity

    NBKB is located on the Hood Canal approximately twenty miles (32 
km) west of Seattle, Washington (see Figures 2-1 through 2-4 in the 
Navy's application). The specified activities with the potential to 
cause harassment of marine mammals within the waterways adjacent to 
NBKB, under the MMPA, are vibratory and impact pile driving operations, 
as well as vibratory removal of falsework piles, associated with the 
wharf construction project. The specified activities that would be 
authorized by this IHA would occur between July 16, 2013, and February 
15, 2014. The allowable season for in-water work, including pile 
driving, at NBKB is July 16 through February 15, which was established 
by the Washington Department of Fish and Wildlife in coordination with 
NMFS and the U.S. Fish and Wildlife Service (USFWS) to protect juvenile 
salmon protected under the Endangered Species Act (ESA). Additional 
details regarding the specified geographic area and construction plans 
for the project were described in our Federal Register notice of 
proposed authorization (78 FR 29705; May 21, 2013; hereafter, the FR 
notice); please see that document or the Navy's application for more 
information.
    As part of the Navy's sea-based strategic deterrence mission, the 
Navy Strategic Systems Programs directs research, development, 
manufacturing, testing, evaluation, and operational support for the 
TRIDENT Fleet Ballistic Missile program. Development of necessary 
facilities for handling of explosive materials is part of these duties. 
The EHW-2 will consist of two components: (1) The wharf proper (or 
Operations Area), including the warping wharf; and (2) two access 
trestles. Please see Figures 1-1 and 1-2 of the Navy's application for 
conceptual and schematic representations of the EHW-2.
    For the entire project, a total of up to 1,250 permanent piles 
ranging in size between 24-48 in (0.6-1.2 m) in diameter will be driven 
in-water to construct the wharf, with up to three vibratory rigs and 
one impact driving rig operating simultaneously. Construction will also 
involve temporary installation of up to 150 falsework piles used as an 
aid to guide permanent piles to their proper locations. Falsework 
piles, which are removed upon installation of the permanent piles, will 
likely be steel pipe piles and will be driven and removed using a 
vibratory driver. It has not been determined exactly what parts or how 
much of the project will be constructed in any given year; however, a 
maximum of 195 days of pile driving may occur per in-water work window. 
The analysis contained herein is based upon the maximum of 195 pile 
driving days, rather than any specific number of piles driven. Table 1 
summarizes the number and nature of piles required for the entire 
project, rather than what subset of piles may be expected to be driven 
during the second year of construction planned for this IHA.

        Table 1--Summary of Piles Required for Wharf Construction
                               [in total]
------------------------------------------------------------------------
                  Feature                             Quantity
------------------------------------------------------------------------
Total number of permanent in-water piles..  Up to 1,250
Size and number of main wharf piles.......  24-in: 140
                                            36-in: 157
                                            48-in: 263
Size and number of warping wharf piles....  24-in: 80
                                            36-in: 190
Size and number of lightning tower piles..  24-in: 40
                                            36-in: 90
Size and number of trestle piles..........  24-in: 57
                                            36-in: 233
Falsework piles...........................  Up to 150, 18- to 24-in
Maximum pile driving duration.............  195 days (under 1-year IHA)
------------------------------------------------------------------------

    Pile installation will employ vibratory pile drivers to the 
greatest extent possible, and the Navy anticipates that most piles will 
be able to be vibratory driven to within several feet of the required 
depth. Pile drivability is, to a large degree, a function of soil 
conditions and the type of pile hammer. Recent experience at two other 
construction locations along the NBKB waterfront indicates that most 
piles should be able to be driven with a vibratory hammer to proper 
embedment depth. However, difficulties during pile driving may be 
encountered as a result

[[Page 43150]]

of obstructions that may exist throughout the project area. Such 
obstructions may consist of rocks or boulders within the glacially 
overridden soils. If difficult driving conditions occur, increased 
usage of an impact hammer will be required. The Navy estimates that up 
to five piles may be proofed in a day, requiring a maximum total of 
1,000 strikes from the impact hammer. Under a worst-case scenario 
(i.e., difficult subsurface driving conditions encountered), as many as 
three piles might require driving with an impact hammer to their full 
embedment depth. With proofing of two additional piles, this scenario 
would result in as many as 6,400 impact pile strikes in a day. Please 
see the FR notice (78 FR 29705; May 21, 2013) for more detail.
    Impact pile driving during the first half of the in-water work 
window (July 16 to September 15) will only occur between 2 hours after 
sunrise and 2 hours before sunset to protect breeding marbled murrelets 
(Brachyramphus marmoratus; an ESA-listed bird under the jurisdiction of 
the USFWS). Between September 16 and February 15, construction 
activities occurring in the water will occur during daylight hours 
(sunrise to sunset). Other construction (not in-water) may occur 
between 7 a.m. and 10 p.m., year-round.

Description of Work Completed

    During the first in-water work season, and during the period of 
validity of the first IHA issued for this project, the contractor 
completed installation of 184 piles to support the main segment of the 
access trestle. Driven piles ranged in size from 24- to 36-in diameter. 
A maximum of two vibratory rigs were operated concurrently and only one 
impact hammer rig was operated at a time. Due to delays in beginning 
construction, pile driving did not begin until September 28, 2012, and 
occurred on 78 days between that date and the end of the work window on 
February 15, 2013. Primarily vibratory driving was conducted; of the 78 
pile driving days, both vibratory and impact driving occurred on 19 
days and impact driving alone occurred on only three days. During the 
second season, installation of the piling for the wharf deck is 
expected to be completed, and it is likely that contractors will more 
closely approach the notional activity levels contemplated in this 
analysis (i.e., 195 days total driving, with both impact and vibratory 
driving occurring on each day). However, the activity level is the 
maximum possible, and unforeseen delays inherent to any construction 
schedule mean that it is not likely that the maximum activity level 
will actually occur.

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 29705; May 21, 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 [mu]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 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 https://www.nmfs.noaa.gov/pr/acoustics/guidelines.htm.
    Sound levels can be greatly reduced during impact pile driving 
using sound attenuation devices. The Navy is required to use sound 
attenuation devices for all impact pile driving, and has elected to use 
bubble curtains. Bubble curtains work by creating a column of air 
bubbles rising around a pile from the substrate to the water surface. 
The air bubbles absorb and scatter sound waves emanating from the pile, 
thereby reducing the sound energy. A confined bubble curtain contains 
the air bubbles within a flexible or rigid sleeve made from plastic, 
cloth, or pipe. Confined bubble curtains generally offer higher 
attenuation levels than unconfined curtains because they may physically 
block sound waves and they prevent air bubbles from migrating away from 
the pile.
    The literature presents a wide array of observed attenuation 
results for bubble curtains (e.g., Oestman et al., 2009, Coleman, 2011, 
Caltrans, 2012). The variability in attenuation levels is due to 
variation in design, as well as differences in site conditions and 
difficulty in properly installing and operating in-water attenuation 
devices. As a general rule, reductions of greater than 10 dB cannot be 
reliably predicted. In the acoustic modeling conducted by the Navy to 
assess project impacts, they assumed that use of a bubble curtain could 
reasonably result in 10 dB of attenuation, and reduced the proxy source 
levels accordingly. Since that initial assessment was completed, site-
specific measurements from the Navy's 2011 Test Pile Project (TPP; 
Illingworth & Rodkin, Inc., 2012), as well as difficulties encountered 
by the Navy's contractors in properly deploying bubble curtains, have 
shown that 8 dB (or possibly less) may be a more realistic assumption 
regarding average SPL (rms) reduction. However, the prior assumption of 
10 dB attenuation is carried forward here. The Navy has committed to 
implementing conservative shutdown zones, as indicated by empirical, 
site-specific measurements that are larger than those predicted from 
the modeling results in order to ensure that the 180/190 dB zones are 
encompassed by protective measures. Prior to any future IHAs, we will 
work with the Navy to more accurately account for the mitigating 
effects of bubble curtain usage. In addition, to avoid loss of 
attenuation from design and implementation errors, the Navy has 
incorporated contractual requirements regarding specific bubble curtain 
design specifications, including testing requirements for air pressure 
and flow prior to initial impact hammer use, and a requirement for 
placement on the substrate.

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 29705; May 21, 2013) for a detailed description of the 
calculations and information used to estimate distances to relevant 
threshold levels. Transmission loss, or the decrease in acoustic 
intensity as an acoustic

[[Page 43151]]

pressure wave propagates out from a source, was estimated as so-called 
``practical spreading loss''. This 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. In the model used here, 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.
    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. A large quantity of 
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 NBKB, studies with similar properties to the 
specified activity were evaluated, including measurements conducted for 
driving of steel piles at NBKB as part of the TPP (Illingworth & 
Rodkin, Inc., 2012). During the TPP, SPLs from driving of 24-, 36-, and 
48-in piles by impact and vibratory hammers were measured. 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 were presented in the FR notice 
(78 FR 29705; May 21, 2013). For impact pile driving, distances to the 
marine mammal sound thresholds were calculated with the assumption of a 
10 dB reduction in source levels from the use of a bubble curtain. For 
impact driving, a source value of 195 dB RMS re 1[mu]Pa at 10 m (185 dB 
used as proxy value) was the average value reported from the listed 
studies, and is consistent with measurements from the TPP and Carderock 
Pier pile driving projects at NBKB, which had similar pile materials 
(48- and 42-inch hollow steel piles, respectively), water depth, and 
substrate type as the EHW-2 project site. For vibratory pile driving, 
the Navy selected the most conservative value (72-in piles; 180 dB rms 
re 1[mu]Pa at 10 m) available when initially assessing EHW-2 project 
impacts, prior to the first year of the project. Since then, data from 
the TPP have become available that indicate, on average, a lower source 
level for vibratory pile driving (172 dB rms re 1[mu]Pa for 48-inch 
steel piles). However, for consistency we have maintained the initial 
conservative assumption regarding source level for vibratory driving. 
All calculated distances to and the total area encompassed by the 
marine mammal sound thresholds are provided in Table 2. Predicted 
distances to thresholds for different sources are shown in Figures 6-1 
and 6-2 of the Navy's application.
    Under the maximum construction scenario, up to three vibratory 
drivers will operate simultaneously with one impact driver. Although 
radial distance and area associated with the zone ensonified to 160 dB 
rms (the behavioral harassment threshold for pulsed sounds, such as 
those produced by impact driving) are presented in Table 2 for 
reference, this zone would be subsumed by the 120 dB rms zone produced 
by vibratory driving. Thus, behavioral harassment of marine mammals 
associated with impact driving is not considered further here. Since 
the 160 dB threshold and the 120 dB threshold both indicate behavioral 
harassment, pile driving effects in the two zones are equivalent. 
Although such a day is not planned, if only the impact driver is 
operated on a given day, incidental take on that day would likely be 
lower because the area ensonified to levels producing Level B 
harassment would be smaller (although actual take would be determined 
by the numbers of marine mammals in the area on that day). The use of 
multiple vibratory rigs at the same time will result in a small 
additive effect with regard to produced SPLs; however, because the 
sound field produced by vibratory driving will be truncated by land in 
the Hood Canal, no increase in actual sound field produced will occur. 
There will be no overlap in the 190/180-dB sound fields produced by 
rigs operating simultaneously.

  Table 2--Calculated Distance(s) to and Area Encompassed by Underwater
         Marine Mammal Sound Thresholds During Pile Installation
------------------------------------------------------------------------
            Threshold                Distance  (m)       Area, km \2\
------------------------------------------------------------------------
Impact driving, pinniped injury                  4.9              0.0001
 (190 dB).......................
Impact driving, cetacean injury                   22               0.002
 (180 dB).......................
Impact driving, disturbance \2\                  724                1.65
 (160 dB).......................
Vibratory driving, pinniped                      2.1            < 0.0001
 injury (190 dB)................
Vibratory driving, cetacean                       10              0.0003
 injury (180 dB)................
Vibratory driving, disturbance            \3\ 13,800    \3\ 41.4 (15.98)
 (120 dB).......................
------------------------------------------------------------------------
\1\ SPLs used for calculations were: 185 dB for impact and 180 dB for
  vibratory driving.
\2\ Area of 160-dB zone presented for reference. Estimated incidental
  take calculated on basis of larger 120-dB zone.
\3\ Hood Canal average width at site is 2.4 km (1.5 mi), and is fetch
  limited from N to S at 20.3 km (12.6 mi). Calculated range (over 222
  km) is greater than actual sound propagation through Hood Canal due to
  intervening land masses. 13.8 km (8.6 mi) is the greatest line-of-
  sight distance from pile driving locations unimpeded by land masses,
  which would block further propagation of sound. 15.98 km is the
  approximate actual area encompassing the 120-dB zone, as demonstrated
  by modeling results.

    Hood Canal does not represent open water, or free field, 
conditions. Therefore, sounds will attenuate as they encounter land 
masses or bends in the canal. As a result, the calculated distance and 
areas of impact for the 120 dB threshold cannot actually be attained at 
the project area. See Figure 6-1 of the Navy's application for a 
depiction of the size of areas in which each underwater sound threshold 
is predicted to occur at the project area due to pile driving.
    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 NBKB 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

[[Page 43152]]

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 NBKB, 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). 
During the TPP, impact driving was measured at 109 dB and vibratory 
driving at 102 dB (at 15 m). We have retained the previous values for 
impact assessment because the value for impact driving, as used in the 
combined rig scenario, results in a more conservative ZOI than does the 
TPP measurement. The Navy has analyzed the combined sound field 
produced under the multi-rig scenario and calculated the radial 
distances to the 90 and 100 dB airborne thresholds as 361 m and 114 m, 
respectively, equating to areas of 0.41 km\2\ and 0.04 km\2\, 
respectively.
    There are no haul-out locations within these zones, which are 
encompassed by the zones estimated for underwater sound. 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. Construction sound associated with the 
project would not extend beyond the buffer zone for underwater sound 
that would be established to protect pinnipeds. No haul-outs or 
rookeries are located within the airborne harassment radii. See Figure 
6-2 of the Navy's application for a depiction of the size of areas in 
which each airborne sound threshold is predicted to occur at the 
project area due to pile driving. We recognize that 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. We 
consider these incidences of harassment to be accounted for in the take 
estimates for underwater sound.

Acoustic Monitoring

    During the first year of construction for EHW-2, the Navy conducted 
acoustic monitoring as required under the IHA. During year one, 24- to 
36-in diameter piles were primarily driven, by vibratory and impact 
driving. Only one 48-in pile was driven, so no data are provided for 
that pile size. All piles were steel pipe piles. Primary objectives for 
the acoustic monitoring were to characterize underwater and airborne 
source levels for each pile size and hammer type and to verify 
distances to relevant threshold levels by characterizing site-specific 
transmission loss. Select results are reproduced here; the interested 
reader may find the entire reports posted at https://www.nmfs.noaa.gov/pr/permits/incidental.htm.

                      Table 3--Acoustic Monitoring Results From 2012-13 Activities at EHW-2
----------------------------------------------------------------------------------------------------------------
                                                                             Underwater             Airborne
           Pile size (in)               Hammer type \1\        n    --------------------------------------------
                                                                      RL \3\   SD \4\   TL \5\   RL \6\     SD
----------------------------------------------------------------------------------------------------------------
24.................................  Impact...............       41      179     24.1     18.6      103      1.0
36.................................  Impact...............       26      188      5.0     14.9      102      2.2
24.................................  Vibratory............       71      163      8.3     15.3       95      3.7
36.................................  Vibratory............      113      169      4.3     16.8      103      3.2
----------------------------------------------------------------------------------------------------------------
\1\ All data for impact driving include use of bubble curtain.
\2\ n = sample size, or number of measured pile driving events.
\3\ Received level at 10 m, presented in dB re: 1 [mu]Pa rms.
\4\ Standard deviation.
\5\ Transmission loss (log10).
\6\ Received level at 15 m, presented in dB re: 20 [mu]Pa rms (Z-weighted Leq).

    For vibratory driving, measured source levels were below the 180-dB 
threshold. Calculation of average distances to the 120-dB threshold was 
complicated by variability in propagation of sound at greater 
distances, variability in measured sounds from event to event, and the 
difficulty of making measurements, given noise from wind and wave 
action, in the far field. Also, as observed during previous monitoring 
events at NBKB, measured levels in shallower water at the far side of 
Hood Canal are sometimes louder than measurements made closer to the 
source in the deeper open channel. These events are unexplained. 
Average radial distances to the 120-dB threshold were 2,765 m for 24-in 
piles and 10,483 m for 36-in piles. However, the topography of Hood 
Canal realistically constrains distances to 7,000 m to the south of the 
project area. For impact driving, calculated average zones (provided 
for 36-in piles) were as follows: 190-dB zone at 12 m; 180-dB zone at 
45 m; and 160-dB zone at 670 m. Measurements of impact driving for 24-
in piles showed a high degree of variation (standard deviation of 24.1) 
because many of these piles were driven either on land or in extremely 
shallow water, while others were driven in deeper water more 
characteristic of typical driving conditions for EHW-2.
    Sound levels during soft starts were typically lower than those 
levels at the initiation and completion of continuous vibratory 
driving. However, levels during continuous driving varied considerably 
and were at times lower than those produced during the soft starts. It 
is difficult to assign a level that describes how much lower the soft 
start sound levels were than continuous levels. Similarly inconclusive 
results were seen from monitoring associated with the TPP.

Comments and Responses

    We published a notice of receipt of the Navy's application and 
proposed IHA in the Federal Register on May 21, 2013 (78 FR 29705). 
NMFS received comments from the Marine Mammal Commission (Commission). 
The Commission's comments and our responses are provided here, and the 
comments have been posted on the

[[Page 43153]]

internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm.
    Comment 1: The Commission recommends that we require the Navy to 
re-estimate the number of harbor seal takes using more recent survey 
data from Tannenbaum et al. (2009, 2011), which is based on the total 
estimated population rather than the Navy's rationale of reducing the 
density for the proportion of seals hauled out and older data.
    Response: As described in greater detail in the FR notice, there 
are two sources of information from which a suitable density estimate 
may be derived for harbor seals. These include aerial surveys of Hood 
Canal (358.4 km\2\) conducted in 1999 and vessel-based marine wildlife 
surveys conducted by the Navy in nearshore waters of NBKB (3.9 km\2\) 
during July through September 2008 and November through May 2009-10. 
Despite the time lapse, these survey efforts produce comparable 
results. Because harbor seals, unlike sea lions, form a resident 
population in Hood Canal and are not known to be attracted to the NBKB 
waterfront by any foraging or haul-out opportunity, it is the opinion 
of both NMFS and the Navy that it is preferable to use the density 
value that is derived from a survey of the entire population. The 
Tannenbaum et al. (2009, 2011) data are not based on the total 
estimated population, but on surveys of a very small section of Hood 
Canal (approximately one percent of the Hood Canal area along the NBKB 
waterfront).
    Based on the 1999 surveys, which also form the basis for the most 
recent abundance estimates provided in NMFS' Stock Assessment Report 
for the Washington inland waters stock of harbor seals, Jeffries et al. 
(2003) estimated the abundance of harbor seals in the Hood Canal as 
1,088 individuals. The resulting density is 3.04 animals/km\2\; 
however, use of this density in estimating take would make the 
assumption that 100 percent of the animals would be in the water at all 
times. Therefore, a factor derived from Huber et al. (2001)--only 35 
percent of seals are in the water at any given time--was applied to 
correct for animals out of the water and not available to be exposed to 
underwater sound; the resulting corrected density of seals in the water 
at any given time is 1.06 animals/km\2\. We note here that previous 
analyses for Navy actions at NBKB used a corrected density of 1.31 
animals/km\2\ that was based on an erroneous understanding of the 
survey area used by Jeffries et al. (2003). The Navy requested that we 
retain the higher density for take estimation associated with this IHA 
because their analyses were already complete, and because the higher 
density would produce an overestimate of take. A separate request for 
incidental take authorization, for the barge mooring project at NBKB, 
uses the lower density estimate based off of an accurate understanding 
of the survey area used by Jeffries et al. (2003). The reason for the 
discrepancy was clearly explained (see page 29728 at 78 FR 29705; May 
21, 2013).
    The Commission disagrees with this approach because of their 
contention that (1) an instantaneous estimate of animals in the water 
at a given time does not produce an accurate assessment of the number 
of individuals that may enter the water over the daily duration of the 
activity and (2) use of the uncorrected density would be consistent 
with our decision to base the number of takes of sea lions on average 
monthly maximum abundance estimates at NBKB haul-out sites, under the 
assumption that each individual present would enter the water and 
therefore be exposed to underwater sound that may result in behavioral 
harassment at some point on any given day. With regard to the second 
point, we note that consistency between approaches for sea lions and 
for harbor seals would not be appropriate. Sea lions are attracted to 
the NBKB waterfront by the presence of submarines and other haul-out 
opportunities. Site-specific data therefore better reflects the nature 
of sea lion occurrence than does a regional density. With regard to the 
first point, as acknowledged in the FR notice (78 FR 29705; May 21, 
2013), we recognize that over the course of a day, while the proportion 
of animals in the water may not vary significantly, different 
individuals may enter and exit the water. That is, it is probable that 
greater than 35 percent of seals will enter the water at some point 
during the day. No data exist regarding fine-scale harbor seal 
movements within the project area on time durations of less than a day, 
thus precluding an assessment of ingress or egress of different animals 
through the action area. As such, it is impossible, given available 
data, to determine exactly what number of individuals above 35 percent 
may potentially be exposed to underwater sound. Therefore, we are left 
to make a decision, on the basis of limited available information, 
regarding which of these two scenarios (i.e., 100 percent vs. 35 
percent of harbor seals are in the water and exposed to sound) produces 
a more accurate estimate of the potential incidents of take.
    First, we understand that hauled-out harbor seals are necessarily 
at haul-outs. No significant harbor seal haul-outs are located within 
or near the action area. Harbor seals observed in the vicinity of the 
NBKB shoreline are rarely hauled-out (for example, in formal surveys 
during 2007-08, approximately 86 percent of observed seals were 
swimming), and when hauled-out, they do so opportunistically (i.e., on 
floating booms rather than established haul-outs). Harbor seals are 
typically unsuited for using manmade haul-outs at NBKB, which are used 
by sea lions. Primary harbor seal haul-outs in Hood Canal are located 
at significant distance (20 km or more) from the action area in Dabob 
Bay or further south (see Figure 4-1 in the Navy's application), 
meaning that animals casually entering the water from haul-outs or 
flushing due to some disturbance at those locations would not be 
exposed to underwater sound from the project; rather, only those 
animals embarking on foraging trips and entering the action area may be 
exposed.
    Second, we know that harbor seals in Hood Canal are not likely to 
have a uniform distribution as is assumed through use of a density 
estimate, but are likely to be relatively concentrated near areas of 
interest such as the haul-outs found in Dabob Bay or foraging areas. 
The majority of the action area consists of the Level B harassment zone 
in deeper waters of Hood Canal; past observations from surveys and 
required monitoring have confirmed that harbor seals are less abundant 
in these waters.
    Third, a typical pile driving day (in terms of the actual time 
spent driving) is much shorter than the 8-15 hours cited by the 
Commission as a representative pile driving day. Construction 
scheduling and notional production rates in concert with typical delays 
mean that hammers are active for only some small fraction of time on 
pile driving ``days''. During the first year of construction for EHW-2, 
vibratory pile driving occurred on 75 days, but only for an approximate 
total time of 71 hours.
    What we know tells us that (1) The turnover of harbor seals (in and 
out of the water) is occurring primarily outside the action area and 
would not be expected to result in a greater number of individuals 
entering the action area within a given day and being harassed than is 
assumed; (2) there are likely to be significantly fewer harbor seals in 
the majority of the action area than would be indicated by the 
uncorrected density; and (3) pile driving actually occurs over a 
limited timeframe on any given day, reducing the amount of time over 
which new individuals might enter the action area within a given day. 
These factors lead us to believe that the corrected

[[Page 43154]]

density is likely to more closely approximate the number of seals that 
may be found in the action area than does the uncorrected density, and 
there are no existing data that would indicate that the proportion of 
individuals entering the water within the predicted area of effect 
during pile driving would be dramatically larger than 35 percent. 
Therefore, the Commission's suggestion that 100 percent of the 
population be used to estimate density would likely result in a gross 
exaggeration of potential take. Moreover, because the Navy is typically 
unable to determine from field observations whether the same or 
different individuals are being exposed, each observation is recorded 
as a new take, although an individual theoretically would only be 
considered as taken once in a given day.
    Finally, we note that during the course of four previous IHAs over 
two years (2011-12), the Navy has been authorized for 6,725 incidents 
of incidental harassment (corrected for actual number of pile driving 
days). The total estimate of actual incidents of take (observed takes 
and observations extrapolated to unobserved area) was 868. This is 
almost certainly negatively biased, but the huge disparity does provide 
confirmation that we are not significantly underestimating takes.
    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 at 78 FR 29705; May 21, 2013). Given that conclusion, 
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 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 the Hood Canal 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 animals within the shutdown zones proposed for this action 
approaches 100 percent. The 190 dB zone for pinnipeds is small, with 
radial distance of only 20 m, while the 180 dB zone for cetaceans (85 
m) is notional only--no cetaceans have ever been recorded as entering 
the security area bounded by the floating port security barrier. 
Regarding availability, the most abundant species, and therefore the 
species most likely to be present in the mitigation zones, are the 
harbor seal and California sea lion.
    It is generally unlikely that a pinniped would remain within 
approximately 20 m of an active construction zone, in the absence of 
any known foraging opportunities or other attractant of any 
significance, for an extended period of time. However, some harbor 
seals have been known to frequent the areas surrounding existing 
wharves at NBKB. Even when this situation does occur, the possibility 
that individuals would remain submerged for a period of time exceeding 
15 minutes is discountable.
    Dive behavior for harbor seals, including typical duration, is 
influenced by a variety of factors, such as behavioral context, local 
bathymetric conditions, and the specific physiological characteristics 
of the animal (e.g., Harkonen, 1987a,b; Eguchi and Harvey, 2005). Dive 
depth may be expected to correlate well with dive duration. However, 
Eguchi and Harvey (2005) showed that average dive durations in Monterey 
Bay, where available depths are much deeper than

[[Page 43155]]

those in the nearshore environment at NBKB, were only 4.8 and 5.5 
minutes for females and males, respectively. Although fine-scale 
population structure exists for harbor seals on a geographic basis from 
California to Alaska (Carretta et al., 2011), similar results have been 
obtained in Alaska and Washington. Dive durations for harbor seals from 
three locations across the Gulf of Alaska were typically less than 4 
minutes across factors (Hastings et al., 2004). Closer to the action 
area in Puget Sound waters, Suryan and Harvey (1998) reported dive 
depths ranging from 3.2-4.6 min. Importantly, those durations were 
reduced in nearshore waters similar to those in the shutdown zone (1.5-
3.6 min). Conversely, dive durations were somewhat longer during 
milling behavior, which is sometimes observed in the action area. 
However, surface intervals (which ranged from 0.6-0.9 min) showed a 
significantly positive correlation to dive duration (Suryan and Harvey, 
1998), meaning that longer dives, or periods of high availability bias, 
are followed by periods of relatively greater availability.
    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, and behavioral observations in the nearshore action area 
show that California sea lions are typically traveling, likely to haul-
out opportunities at Delta Pier.
    Under the typically excellent observation conditions found in the 
Hood Canal, we believe that surfaced animals would be observed. 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 the Hood Canal.
    Comment 3: The Commission recommends that we require the Navy to 
consult with the Washington State Department of Transportation and/or 
the California Department of Transportation to (1) determine whether 
soft start procedures can be used safely with the vibratory hammers 
that the Navy plans to use prior to eliminating the Navy's requirement 
to implement those measures and (2) clarify and troubleshoot the sound 
attenuation device implementation procedures to ensure the device's 
efficacy.
    Response: We concur with the first part of the Commission's 
recommendation and will facilitate the suggested consultation. However, 
this cannot be accomplished prior to issuance of the IHA due to the 
Navy's operational needs. Accordingly, we deem vibratory soft starts to 
not currently be practicable due to safety concerns. We will determine 
whether the potentially significant human safety issue is inherent to 
implementation of the measure or is due to operator error prior to 
issuing any further IHAs to the Navy for pile driving activities in 
2014 and beyond.
    With regard to sound attenuation device implementation, we 
previously required the Navy to use such a device and to require that 
their contractors ensure: (1) that the device be capable of achieving 
attenuation performance of 10 dB of reduction and (2) that the device 
is properly deployed such that no reduction in performance may be 
attributable to operator error. However, because recent observations 
indicate that achievement of 10 dB of attenuation performance may not 
be reasonable, we now stipulate simply that the Navy must make the 
necessary contractual requirements to ensure that the device is capable 
of achieving optimal performance, and that deployment of the device is 
implemented properly such that no reduction in performance may be 
attributable to faulty deployment. Compliance with this stipulation is 
incumbent upon the Navy and it would not be appropriate for us to 
dictate the manner of compliance, including requirements for 
consultation with third parties.
    Comment 4: 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 those mammals.
    Response: We believe that we have developed, in consultation with 
the Navy, a strategy that is appropriate to accomplish the stated 
objectives of the Commission's recommendation. The Commission states 
that the goal is not simply to employ a strategy that ensures 
monitoring out to a certain distance, but rather to employ a strategy 
that provides the information necessary to determine if the 
construction activities have adverse effects on marine mammals and to 
describe the nature and extent of those effects. We agree with that 
statement, and note that the Navy does not simply monitor within 
defined zones, ignoring occurrences outside those zones. The mitigation 
strategy is designed to implement shutdown of activity only for marine 
mammal occurrence within designated zones, but all observations of 
marine mammals and any observed behavior, whether construed as a 
reaction to project activity or not, are recorded regardless of 
distance to project activity. This information is coupled with the 
results of previous acoustic monitoring data (i.e., sound levels 
recorded at multiple defined distances from the activity) to draw 
conclusions about the impact of the activity on marine mammals. 
Importantly, the larger monitoring effort conducted by the Navy in 
deeper waters of Hood Canal during their 2011 project monitoring was an 
important piece of the Navy's overall monitoring strategy for the 
ongoing suite of actions at NBKB and may reasonably be used as a 
reference for the current activities. Using that information, as well 
as the results of required monitoring associated with the 2011-12 Test 
Pile Program, 2011-13 rehabilitation of the existing Explosives 
Handling Wharf, and the first year of construction for the EHW-2, we 
believe we have gained a sufficient understanding of marine mammal 
behavior in response to the specified activities, as well as occurrence 
and behavior within the Level B harassment zone in deeper waters beyond 
the waterfront restricted area, which is intensively monitored. We also 
note that the de facto zone of monitoring effort has been expanded for 
the duration of the concurrent barge mooring effort, as observers 
monitoring the waterfront at that location will also be collecting 
information on occurrence and potential reactions of marine mammals.
    The Commission urges us to consider a more comprehensive approach 
to assessment of effects of activities co-located in time and space. We 
believe that the Navy has designed a comprehensive, multi-year approach 
for its monitoring strategy. It is not fiscally feasible, or the best 
use of resources, to deploy multiple vessel-based observers for year 
after year of similar activities. A strategic approach demands front-
loaded effort that, when properly

[[Page 43156]]

designed, provides utility for subsequent years. Beginning in 2008, the 
Navy began to expand their efforts to better understand nature and 
frequency of occurrence for wildlife at NBKB. Opportunistic haul-out 
surveys and vessel-based wildlife surveys have been useful in 
evaluating the potential effects of construction activities. At the 
initiation of the recent construction activities, the Navy mounted an 
intensive monitoring effort, including deep-water monitoring (that was 
not mitigation-specific) and comprehensive acoustic monitoring, with 
the express purpose of providing a robust body of data that would form 
a reference for evaluation of future effects of similar activities. In 
addition, the Navy has proactively secured funding and sought 
collaboration with NMFS and other experts to conduct future surveys of 
Washington inland waters that will provide much-needed updates to our 
understanding of marine mammal abundance and distribution in the 
region.
    Comment 5: The Commission recommends that we complete an analysis 
of the impact of the proposed activities together with the cumulative 
impacts of all the other pertinent risk factors (including but not 
limited to the Navy's concurrent barge mooring project) for marine 
mammals in the Hood Canal area.
    Response: Section 101(a)(5)(D) of the MMPA requires NMFS to make a 
determination that the harassment incidental to a specified activity 
will have a negligible impact on the affected species or stocks of 
marine mammals, and will not result in an unmitigable adverse impact on 
the availability of marine mammals for taking for subsistence uses. 
Neither the MMPA nor NMFS' implementing regulations specify how to 
consider other activities and their impacts on the same populations. 
However, consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into the 
negligible impact analysis via their impacts on the environmental 
baseline (e.g., as reflected in the density/distribution and status of 
the species, population size and growth rate, and ambient noise).
    In addition, cumulative effects were addressed in the Navy's 
Environmental Impact Statement and in the biological opinion prepared 
for this action, as well as in the NEPA analyses prepared for other 
actions conducted at the NBKB waterfront. These documents, as well as 
the relevant Stock Assessment Reports, are part of NMFS' Administrative 
Record for this action, and provided the decision-maker with 
information regarding other activities in the action area that affect 
marine mammals, an analysis of cumulative impacts, and other 
information relevant to the determination made under the MMPA.
    Comment 6: The Commission recommends that we encourage the Navy to 
combine future requests for IHAs for all activities that would occur in 
the same general area and within the same year rather than segmenting 
those activities and their associated impacts by requesting separate 
authorizations.
    Response: We agree with the Commission's recommendation and have 
encouraged the Navy to do so. However, we do not have the statutory 
authority to require the Navy to combine such requests. With our 
encouragement, the Navy is working to develop a regionally 
comprehensive approach to environmental compliance for reasonably 
foreseeable small actions, such as pile replacement and repair 
projects. A major project such as the current EHW-2 construction would 
likely remain as a standalone effort due to constraints related to 
planning, funding, and contracting.
    Comment 7: The Commission recommends that we require the Navy to 
use the same data (e.g., source levels, sound attenuation factors, 
densities), methods, and justification for all pile driving and removal 
activities that occur during the same timeframe at NBKB.
    Response: We concur with the Commission's recommendation and will 
require consistency from the Navy in future IHA requests. However, we 
are not overly concerned here because where there are inconsistencies 
they are due to use of conservative approaches. For example, in 
discussing source levels used for determining mitigation zones, the 
Commission notes that the Navy used a conservative estimate (i.e., the 
maximum source level) for the barge mooring project, but did not do so 
for the EHW-2. While the approach differs, conservatism is also built 
into the estimation of mitigation zones for EHW-2, not through use of a 
conservative source level, but by using the maximum radial distances to 
relevant thresholds, as measured during in site-specific acoustic 
monitoring. The modeled zones for the EHW-2 project were 22 and 5 m for 
the 180 and 190 dB zones, respectively, but the zones required of the 
Navy are 85 and 20 m, respectively. This more conservative approach was 
adopted at the urging and with the concurrence of the Commission in 
2012. The Commission states that it is unclear why these 
inconsistencies are present, however, in each case the reason for the 
inconsistency and the rationale for our decision that use of an 
inconsistent approach is acceptable, if not desirable, is clearly 
presented in the associated FR notices.

Description of Marine Mammals in the Area of the Specified Activity

    There are seven marine mammal species, four cetaceans and three 
pinnipeds, which may inhabit or transit through the waters nearby NBKB 
in the Hood Canal. These include the transient killer whale, harbor 
porpoise, Dall's porpoise, Steller sea lion, California sea lion, 
harbor seal, and humpback whale. The Steller sea lion and humpback 
whale are the only marine mammals that may occur within the Hood Canal 
that are listed under the Endangered Species Act (ESA); the humpback 
whale is listed as endangered and the eastern distinct population 
segment (DPS) of Steller sea lion is listed as threatened. The Steller 
sea lion is typically present in low numbers in the Hood Canal only 
from approximately October through mid-April. The humpback whale is not 
typically present in Hood Canal, with no confirmed sightings found in 
the literature or the Orca Network database (https://www.orcanetwork.org/) prior to January and February 2012, when one 
individual was observed repeatedly over a period of several weeks. No 
sightings have been recorded since that time and we consider the 
humpback whale to be a rare visitor to Hood Canal at most. While the 
southern resident killer whale is resident to the inland waters of 
Washington and British Columbia, it has not been observed in the Hood 
Canal in over 15 years. Therefore, these three stocks were excluded 
from further analysis. The FR notice (78 FR 29705; May 21, 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 29705; May 21, 2013) provides a detailed description of 
marine mammal hearing and of the potential effects of

[[Page 43157]]

these construction activities on marine mammals.

Anticipated Effects on Habitat

    The specified activities at NBKB 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 and salmonids. There are no rookeries or major haul-out 
sites within 10 km (6.2 mi), foraging hotspots, or other ocean bottom 
structures 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, as discussed previously in this 
document. The most likely impact to marine mammal habitat occurs from 
pile driving effects on likely marine mammal prey (i.e., fish) near 
NBKB and minor impacts to the immediate substrate during construction 
activity associated with the EHW-2 project. The FR notice (78 FR 29705; 
May 21, 2013) describes these potential impacts in greater detail.

Summary of Previous Monitoring

    The Navy complied with the mitigation and monitoring required under 
the previous authorization for this project. In accordance with the 
2012 IHA, the Navy submitted a Year 1 Marine Mammal Monitoring Report 
(2012-2013), covering the period of July 16 through February 15. Due to 
delays in beginning the project the first day of monitored pile driving 
activity occurred on September 28, 2012, and a total of 78 days of pile 
driving occurred between then and February 14, 2013. That total 
included 56 days of vibratory driving only, three days of only impact 
driving, and 19 days where both vibratory and impact driving occurred. 
Marine mammal monitoring occurred the before, during, and after each 
pile driving event. During the course of these activities, the Navy did 
not exceed the take levels authorized under the IHA. For more detail, 
including full monitoring results and analysis, please see the 
monitoring report at https://www.nmfs.noaa.gov/pr/permits/incidental.htm.

Mitigation

    In order to issue an incidental take authorization (ITA) under 
Section 101(a)(5)(D) of the MMPA, we must, where applicable, 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).
    Measurements from similar pile driving events were coupled with 
practical spreading loss 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 NBKB. 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 other than pile driving 
(using, e.g., standard barges, tug boats, barge-mounted excavators, or 
clamshell equipment used to place or remove material), if a marine 
mammal comes within 10 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; (2) 
positioning of the pile on the substrate via a crane (i.e., stabbing 
the pile); (3) removal of the pile from the water column/substrate via 
a crane (i.e., deadpull); or (4) the placement of sound attenuation 
devices around the piles. 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. Modeled 
distances for shutdown zones are shown in Table 2. However, during 
impact pile driving, the Navy would implement a minimum shutdown zone 
of 85 m radius for cetaceans and 20 m for pinnipeds around all pile 
driving activity. The modeled injury threshold distances are 
approximately 22 and 5 m, respectively, but the distances are increased 
based on in-situ recorded sound pressure levels from the TPP. During 
vibratory driving, the shutdown zone would be 10 m distance from the 
source for all animals. These precautionary measures are intended to 
act conservatively in the implementation of the measure and further 
reduce any possibility of acoustic injury, as well as to account for 
any undue reduction in the modeled zones stemming from the assumption 
of 10 dB attenuation from use of a bubble curtain.
    Disturbance Zone--Disturbance zones are the areas in which SPLs 
equal or exceed 160 and 120 dB rms (for pulsed and 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. Given the size of the disturbance zone for vibratory pile 
driving, it is impossible to guarantee that all animals would be 
observed or to make comprehensive observations of fine-scale behavioral 
reactions to sound, and only a portion of the zone (e.g., what may be 
reasonably observed by visual observers stationed within the water

[[Page 43158]]

front restricted area [WRA]) will be monitored.
    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 would 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 will be 
halted. Monitoring will take place from 15 minutes prior to initiation 
through 15 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. Please see the Marine Mammal 
Monitoring Plan (available at https://www.nmfs.noaa.gov/pr/permits/incidental.htm), developed by the Navy in agreement with us, for full 
details of the monitoring protocols.
    The following additional measures apply to visual monitoring:
    (1) Monitoring will be conducted by qualified observers, who will 
be placed at the best vantage point(s) practicable to monitor for 
marine mammals and implement shutdown/delay procedures when applicable 
by calling for the shutdown to the hammer operator. 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.

Sound Attenuation Devices

    Bubble curtains shall be used during all impact pile driving. The 
device will distribute air bubbles around 100 percent of the piling 
perimeter for the full depth of the water column, and the lowest bubble 
ring shall be in contact with the mudline for the full circumference of 
the ring. Testing of the device by comparing attenuated and 
unattenuated strikes is not possible because of requirements in place 
to protect marbled murrelets (an ESA-listed bird species under the 
jurisdiction of the USFWS). However, in order to avoid loss of 
attenuation from design and implementation errors in the absence of 
such testing, a performance test of the device shall be conducted prior 
to initial use. The performance test shall confirm the calculated 
pressures and flow rates at each manifold ring. In addition, the 
contractor shall also train personnel in the proper balancing of air 
flow to the bubblers and shall submit an inspection/performance report 
to the Navy within 72 hours following the performance test.

Timing Restrictions

    In Hood Canal, designated exist timing restrictions for pile 
driving activities to avoid in-water work when salmonids and other 
spawning forage fish are likely to be present. The in-water work window 
is July 16-February 15. The initial months (July to September) of the 
timing window overlap with times when Steller sea lions are not 
expected to be present within the project area. Until September 23, 
impact pile driving will only occur starting two hours after sunrise 
and ending two hours before sunset due to marbled murrelet nesting 
season. After September 23, in-water construction activities will occur 
during daylight hours (sunrise to sunset).

Soft Start

    The use of a soft-start procedure is believed to provide additional 
protection to marine mammals by warning or providing a chance to leave 
the area prior to the hammer operating at full capacity, and typically 
involves a requirement to initiate sound from vibratory hammers for 
fifteen seconds at reduced energy followed by a 30-second waiting 
period. This procedure is repeated two additional times. However,

[[Page 43159]]

implementation of soft start for vibratory pile driving during previous 
pile driving work at NBKB has led to equipment failure and serious 
human safety concerns; those issues were detailed in the FR notice (78 
FR 29705; May 21, 2013). Therefore, vibratory soft start is not 
required as a mitigation measure for this project, as we have 
determined it to not currently be practicable due to safety concerns. 
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 strikes from the impact 
hammer at reduced energy, followed by a 30-second waiting period, then 
two subsequent reduced energy strike sets. The reduced energy of an 
individual hammer cannot be quantified because of variation in 
individual drivers. 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''. Soft start for impact driving will be required at 
the beginning of each day's pile driving work and at any time following 
a cessation of impact pile driving of 30 minutes or longer.
    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 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, where applicable, 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 action area. Please see the Navy's Marine Mammal 
Monitoring Plan for full details of the requirements for monitoring and 
reporting.

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, with observers located at the best 
practicable vantage points. Based on our requirements, the Marine 
Mammal Monitoring Plan would implement the following procedures for 
pile driving:
     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.
    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.

Reporting

    A draft report must be submitted to NMFS within 90 calendar days of 
the completion of the in-water work window. 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 problems encountered in deploying sound attenuating devices, 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.

Estimated Take by Incidental Harassment

    With respect to the activities described here, the MMPA defines 
``harassment'' as: ``Any act of pursuit,

[[Page 43160]]

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. 
For example, during the past ten years, killer whales have been 
observed within the project area twice. On the basis of that 
information, an estimated amount of potential takes for killer whales 
is presented here. However, while a pod of killer whales could 
potentially visit again during the project timeframe, and thus be 
taken, it is more likely that they will not. Although incidental take 
of killer whales and Dall's porpoises was authorized for 2011-12 
activities at NBKB on the basis of past observations of these species, 
no such takes were recorded and no individuals of these species were 
observed. Similarly, estimated actual take levels (observed takes 
extrapolated to the remainder of unobserved but ensonified area) were 
significantly less than authorized levels of take for the remaining 
species.
    The project area is not believed to be particularly important 
habitat for marine mammals, nor is it considered an area frequented by 
marine mammals, although harbor seals are year-round residents of Hood 
Canal and sea lions are known to haul-out on submarines and other man-
made objects at the NBKB waterfront (although typically at a distance 
of a mile or greater from the project site). 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 Steller sea lions, California sea lions, harbor seals, 
transient killer whales, Dall's porpoises, and harbor porpoises in the 
Hood Canal that may result from pile driving during construction 
activities associated with the wharf construction project described 
previously in this document.

Marine Mammal Densities

    The Navy is in the process of developing, with input from regional 
marine mammal experts, estimates of marine mammal densities in 
Washington inland waters for the Navy Marine Species Density Database 
(NMSDD). A technical report will describe methodologies used to derive 
these densities, which are generally considered the best available 
information for Washington inland waters, except where specific local 
abundance information is available. Initial take estimates and impact 
assessment for the EHW-2 project relied on data available at the time 
the application was submitted, including survey efforts in the project 
area. For future projects at NBKB, it is likely that the NMSDD 
densities will be used in assessing project impacts. However, because 
the NMSDD report is not complete, and because use of the previous 
density or abundance information results in more conservative (i.e., 
higher) take estimates, the approach to take estimation used for the 
first year of EHW-2 construction is largely retained here. Please see 
Appendix A of the Navy's application for more information on the NMSDD 
information.
    For all species, the most appropriate information available was 
used to estimate the number of potential incidences of take. For harbor 
seals, this involved published literature describing harbor seal 
research conducted in Washington and Oregon as well as more specific 
counts conducted in Hood Canal (Huber et al., 2001; Jeffries et al., 
2003). Killer whales are known from two periods of occurrence (2003 and 
2005) and are not known to preferentially use any specific portion of 
the Hood Canal. Therefore, density was calculated as the maximum number 
of individuals present at a given time during those occurrences 
(London, 2006), divided by the area of Hood Canal. The best information 
available for the remaining species in Hood Canal came from surveys 
conducted by the Navy at the NBKB waterfront or in the vicinity of the 
project area.
    Beginning in April 2008, Navy personnel have recorded sightings of 
marine mammals occurring at known haul-outs along the NBKB waterfront, 
including docked submarines or other structures associated with NBKB 
docks and piers and the nearshore pontoons of the floating security 
fence. Sightings of marine mammals within the waters adjoining these 
locations were also recorded. Sightings were attempted whenever 
possible during a typical work week (i.e., Monday through Friday), but 
inclement weather, holidays, or security constraints often precluded 
surveys. These sightings took place frequently, although without a 
formal survey protocol. During the surveys, staff visited each of the 
above-mentioned locations and recorded observations of marine mammals. 
Surveys were conducted using binoculars and the naked eye from 
shoreline locations or the piers/wharves themselves. Because these 
surveys consist of opportunistic sighting data from shore-based 
observers, largely of hauled-out animals, there is no associated survey 
area appropriate for use in calculating a density from the abundance 
data. Data were compiled for the period from April 2008 through 
December 2012 for analysis here, and these data provide the basis for 
take estimation for Steller and California sea lions. Other 
information, including sightings data from other Navy survey efforts at 
NBKB, is available for these two species, but these data provide the 
most conservative (i.e., highest) local abundance estimates (and thus 
the highest estimates of potential take).
    In addition, vessel-based marine wildlife surveys were conducted 
according to established survey protocols during July through September 
2008 and November through May 2009-10 (Tannenbaum et al., 2009, 2011). 
Eighteen complete surveys of the nearshore area resulted in 
observations of four marine mammal species (harbor seal, California sea 
lion, harbor porpoise, and Dall's porpoise). These surveys operated 
along pre-determined

[[Page 43161]]

transects parallel to the shoreline from the nearshore out to 
approximately 1,800 ft (549 m) from shoreline, at a spacing of 100 yd, 
and covered the entire NBKB waterfront (approximately 3.9 km\2\ per 
survey) at a speed of 5 kn or less. Two observers recorded sightings of 
marine mammals both in the water and hauled out, including date, time, 
species, number of individuals, age (juvenile, adult), behavior 
(swimming, diving, hauled out, avoidance dive), and haul-out location. 
Positions of marine mammals were obtained by recording distance and 
bearing to the animal with a rangefinder and compass, noting the 
concurrent location of the boat with GPS, and, subsequently, analyzing 
these data to produce coordinates of the locations of all animals 
detected. These surveys resulted in the only observation of a Dall's 
porpoise near NBKB.
    The Navy also conducted vessel-based line transect surveys in Hood 
Canal on non-construction days during the 2011 TPP in order to collect 
additional data for species present in Hood Canal. These surveys 
detected three marine mammal species (harbor seal, California sea lion, 
and harbor porpoise), and included surveys conducted in both the main 
body of Hood Canal, near the project area, and baseline surveys 
conducted for comparison in Dabob Bay, an area of Hood Canal that is 
not affected by sound from Navy actions at the NBKB waterfront. The 
surveys operated along pre-determined transects that followed a double 
saw-tooth pattern to achieve uniform coverage of the entire NBKB 
waterfront. The vessel traveled at a speed of approximately 5 kn when 
transiting along the transect lines. Two observers recorded sightings 
of marine mammals both in the water and hauled out, including the date, 
time, species, number of individuals, and behavior (swimming, diving, 
etc.). Positions of marine mammals were obtained by recording the 
distance and bearing to the animal(s), noting the concurrent location 
of the boat with GPS, and subsequently analyzing these data to produce 
coordinates of the locations of all animals detected. Sighting 
information for harbor porpoises was corrected for detectability (g(0) 
= 0.54; Barlow, 1988; Calambokidis et al., 1993; Carretta et al., 
2001). Distance sampling methodologies were used to estimate densities 
of animals for the data. This information provides the best information 
for harbor porpoises.
    The cetaceans, as well as the harbor seal, appear to range 
throughout Hood Canal; therefore, the analysis for this IHA assumes 
that harbor seal, transient killer whale, harbor porpoise, and Dall's 
porpoise are uniformly distributed in the project area. However, it 
should be noted that there have been no observations of cetaceans 
within the floating security barriers at NBKB; these barriers thus 
appear to effectively prevent cetaceans from approaching the shutdown 
zones. Although the Navy will implement a precautionary shutdown zone 
for cetaceans, anecdotal evidence suggests that cetaceans are not at 
risk of Level A harassment at NBKB even from louder activities (e.g., 
impact pile driving). The remaining species that occur in the project 
area, Steller sea lion and California sea lion, do not appear to 
utilize most of Hood Canal. The sea lions appear to be attracted to the 
man-made haul-out opportunities along the NBKB waterfront while 
dispersing for foraging opportunities elsewhere in Hood Canal. 
California sea lions were not reported during aerial surveys of Hood 
Canal (Jeffries et al., 2000), and Steller sea lions have only been 
documented at the NBKB waterfront.

Description of Take Calculation

    The take calculations presented here rely on the best data 
currently available for marine mammal populations in the Hood Canal. 
The methodology for estimating take was described in detail in the FR 
notice (78 FR 29705; May 21, 2013). The ZOI impact area is the 
estimated range of impact to the sound criteria. The distances 
specified in Table 2 were used to calculate ZOIs around each pile. All 
impact pile driving take calculations were based on the estimated 
threshold ranges assuming attenuation of 10 dB from use of a bubble 
curtain. The ZOI impact area took into consideration the possible 
affected area of the Hood Canal from the pile driving site furthest 
from shore with attenuation due to land shadowing from bends in the 
canal. Because of the close proximity of some of the piles to the 
shore, the narrowness of the canal at the project area, and the maximum 
fetch, 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 (typically a matter of hours on any given day) is 
actually spent pile driving. Acoustic monitoring conducted as part of 
the TPP demonstrated that Level B harassment zones for vibratory pile 
driving are likely to be significantly smaller than the zones estimated 
through modeling based on measured source levels and practical 
spreading loss. Also of note is the fact that the effectiveness of 
mitigation measures in reducing takes is typically not quantified in 
the take estimation process. Here, we do explicitly account for an 
assumed level of efficacy for use of the bubble curtain, but not for 
the soft start associated with impact driving. In addition, equating 
exposure with response (i.e., a behavioral response meeting the 
definition of take under the MMPA) is simplistic and conservative 
assumption. For these reasons, these take estimates are likely to be 
conservative.
    Airborne Sound--No incidents of incidental take resulting solely 
from airborne sound are likely, as distances to the harassment 
thresholds would not reach areas where pinnipeds may haul out. Harbor 
seals can haul out at a variety of natural or manmade locations, but 
the closest known harbor seal haul-out is at the Dosewallips River 
mouth (London, 2006) and Navy waterfront surveys and boat surveys have 
found it rare for harbor seals to haul out along the NBKB waterfront 
(Agness and Tannenbaum, 2009; Tannenbaum et al., 2009, 2011; Navy, 
2010). Individual seals have occasionally been observed hauled out on 
pontoons of the floating security fence within the restricted areas of 
NBKB, but this area is not with the airborne disturbance ZOI. Nearby 
piers are elevated well above the surface of the water and are 
inaccessible to pinnipeds, and seals have not been observed hauled out 
on the adjacent shoreline. Sea lions typically haul out on submarines 
docked at Delta Pier, approximately one mile from the project site.
    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 `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.
    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 29705; May 21, 2013). A 
summary of

[[Page 43162]]

the information and assumptions that went into take estimates for each 
species is provided here. Total take estimates are presented in Table 
4.
     California sea lions--Data from waterfront surveys at NBKB 
was most appropriate, because haul-out opportunities provided by 
submarines at Delta Pier are the primary attractant for sea lions in 
the project vicinity and local abundances are higher than indicated by 
regional densities. In order to provide a margin of conservatism, the 
monthly averages for maximum daily numbers observed (in a given month) 
were used to estimate an average maximum daily abundance for the work 
window. Exposures were calculated assuming 31 individuals could be 
present, and therefore exposed to sound exceeding the behavioral 
harassment threshold, on each day of pile driving.
     Steller sea lions--The same data were used for Steller sea 
lions as for California sea lions, for the same reasons. Exposures were 
calculated assuming two individuals could be present, and therefore 
exposed to sound exceeding the behavioral harassment threshold, on each 
day of pile driving.
     Harbor seals--Data from Huber et al. (2001) and Jeffries 
et al. (2003) were used to produce a corrected instantaneous density 
for harbor seals in Hood Canal that accounts for animals in the water 
versus hauled out at any given time. Recently, the Navy discovered 
errors in those calculations (a smaller area was assumed for Hood Canal 
than was used in the initial surveys) that resulted in a higher density 
(1.31 vs. 1.06 animals/km\2\). The earlier density was retained here as 
it provides a more conservative estimate of potential incidences of 
behavioral harassment.
     Killer whales--Regional density values produce an estimate 
of zero incidences of harassment. However, pods of transient killer 
whales have been observed in Hood Canal in 2003 and 2005, for a minimum 
of 59 days. In order to account for the possibility that killer whales 
could be present, we assume a pod size of six whales and a residence 
time of half the previous minimum (to account for likely avoidance of 
harassing stimuli) for estimating potential incidences of behavioral 
harassment (six individuals present for thirty days). We believe that 
this is likely a very conservative estimate.
     Dall's porpoise--Regional density values produce an 
estimate of zero incidences of harassment. However, a Dall's porpoise 
has been observed in waters off of NBKB, and the Navy has requested 
take authorization for this species. In order to account for possible 
presence of this species, and in the absence of information indicating 
any particular proportion of days, we assume that one porpoise could be 
present on each day of pile driving. This is not likely to be a very 
realistic estimate, as no Dall's porpoise has been observed in the past 
two years of monitoring at NBKB. It is, however, a reasonable 
compromise between the only available information and the Navy's 
request for take authorization.
     Harbor porpoise--Surveys from 2011 collected in waters off 
of NBKB provide the best data for this species. Preliminary results 
from those surveys indicated a density of 0.25 animals/km\2\, and this 
value was used by the Navy in initial impact assessments. Additional 
data subsequently produced a revised density estimate of 0.149 animals/
km\2\; however, the Navy has requested that we retain the earlier value 
as it produces a more conservative estimate of potential incidences of 
behavioral harassment.
    Potential takes could occur if individuals of these species are 
present in the vicinity when pile driving is occurring. Individuals 
that are taken could exhibit behavioral changes such as increased 
swimming speeds, increased surfacing time, or decreased foraging. Most 
likely, individuals may move away from the sound source and be 
temporarily displaced from the areas of pile driving. Potential takes 
by disturbance would likely have a negligible short-term effect on 
individuals and not result in population-level impacts.

                         Table 4--Number of Potential Incidental Takes of Marine Mammals within Various Acoustic Threshold Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                        Underwater                     Airborne
                                                                         ------------------------------------------------------------
                                                              Density/                             Vibratory                           Total authorized
                         Species                             abundance       Impact injury        disturbance     Impact disturbance         takes
                                                                             threshold \1\      threshold  (120      threshold \3\
                                                                                                    dB) \2\
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion......................................  \4\ 31.2                        0               6,045                   0               6,045
Steller sea lion.........................................   \4\ 1.7                        0                 390                   0                 390
Harbor seal..............................................       1.31                       0              10,530                   0              10,530
Killer whale.............................................   \5\ 0.0019                     0                 180                 N/A                 180
Dall's porpoise..........................................   \5\ 0.000001                   0                 195                 N/A                 195
Harbor porpoise..........................................       0.250                      0               1,950                 N/A               1,950
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ Acoustic injury threshold for impact pile driving is 190 dB for pinnipeds and 180 dB for cetaceans.
\2\ The 160-dB acoustic harassment zone associated with impact pile driving would always be subsumed by the 120-dB harassment zone produced by vibratory
  driving. Therefore, takes are not calculated separately for the two zones.
\3\ Acoustic disturbance threshold is 100 dB for sea lions and 90 dB for harbor seals. We do not believe that pinnipeds would be available for airborne
  acoustic harassment because they are not known to regularly haul-out at locations inside the zone in which airborne acoustic harassment could occur.
\4\ Figures presented are abundance numbers, not density, and are calculated as the average of average daily maximum numbers per month. Abundance
  numbers are rounded to the nearest whole number for take estimation.
\5\ Density values not used for take estimation. Assumptions are that a pod of six killer whales could be present for thirty days and that one Dall's
  porpoise could be present on each day of pile driving.

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.

[[Page 43163]]

Small Numbers Analysis

    The numbers of animals authorized to be taken for Steller and 
California sea lions and for Dall's porpoises would be considered small 
relative to the relevant stocks or populations (less than one percent 
for Steller sea lions and Dall's porpoise and less than three percent 
for California sea lions) even if each estimated taking occurred to a 
new individual--an extremely unlikely scenario. For pinnipeds occurring 
at the NBKB waterfront, there will almost certainly be some overlap in 
individuals present day-to-day and, for the Dall's porpoise, given the 
rare occurrence of this species in the Hood Canal it seems likely that 
for the number of takes contemplated here to occur, at least one to 
several individuals would have to remain in the area for an extended 
period of time. Further, for the pinniped species, these takes could 
potentially occur only within some small portion of the overall 
regional stock. For example, of the estimated 296,500 California sea 
lions, only certain adult and subadult males--believed to number 
approximately 3,000-5,000 by Jeffries et al. (2000)--travel north 
during the non-breeding season. That number has almost certainly 
increased with the population of California sea lions--the 2000 Stock 
Assessment Report for California sea lions reported an estimated 
population size of 204,000-214,000 animals--but likely remains a 
relatively small portion of the overall population.
    For harbor seals, animals found in Hood Canal belong to a closed, 
resident population estimated at approximately 1,000 animals by 
Jeffries et al. (2003), and takes are likely to occur only within some 
portion of that closed population, rather than to animals from the 
Washington inland waters stock as a whole. The animals that are 
resident to Hood Canal, to which any incidental take would accrue, 
represent only seven percent of the best estimate of regional stock 
abundance. For transient killer whales, we estimate take based on an 
assumption that a single pod of whales, comprising six individuals, is 
present in the vicinity of the project area for the entire duration of 
the project. These six individuals represent a small number of 
transient killer whales, for which a conservative minimum estimate of 
354 animals was given in the 2011 Stock Assessment Reports.
    Little is known about harbor porpoise use of Hood Canal, and prior 
to monitoring associated with recent pile driving projects at NBKB, it 
was believed that harbor porpoises were infrequent visitors to the 
area. It is unclear from the limited information available what 
relationship harbor porpoise occurrence in Hood Canal may hold to the 
regional stock or whether similar usage of Hood Canal may be expected 
to be recurring. It is unknown how many unique individuals are 
represented by sightings in Hood Canal, although it is unlikely that 
these animals represent a large proportion of the overall stock. While 
we believe that the authorized numbers of incidental take would likely 
to occur to a much smaller number of individuals, the number of 
incidences of take relative to the stock abundance (approximately 
eighteen percent) remains within the bounds of what we consider to be 
small numbers.
    As described in the FR notice (78 FR 29705; May 21, 2013) and 
summarized here, the estimated number of potential incidences of 
harassment for these species are likely much higher than will 
realistically occur. This is because (1) We use the maximum possible 
number of days (195) in estimating take, despite the fact that multiple 
delays and work stoppages are likely to result in a significantly lower 
number of actual pile driving days; (2) estimates for harbor porpoise 
and harbor seal rely on density estimates that are higher than what we 
consider to be the best available information; (3) sea lion estimates 
rely on the averaged maximum daily abundances per month, rather than 
simply an overall average which would provide a much lower abundance 
figure; and (4) the estimates for killer whale and Dall's porpoise use 
sparse information to attempt to account for the potential presence of 
species that have not been observed in Hood Canal since 2005 and 2008 
(when a single individual was observed), respectively. In addition, 
with the exception of the bubble curtain, potential efficacy of 
mitigation measures in terms of reduction in numbers and/or intensity 
of incidences of take has not been quantified. Therefore, these take 
numbers are likely to be conservative.

Negligible Impact Analysis

    Pile driving activities associated with the wharf construction 
project, as outlined previously, have the potential to disturb or 
displace marine mammals. Specifically, the specified activities may 
result in take, in the form of Level 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, which is likely to occur because (1) Harbor seals, which are 
frequently observed along the NBKB waterfront, are present within the 
WRA; (2) sea lions, which are less frequently observed, transit the WRA 
en route to haul-outs to the south at Delta Pier; or (3) cetaceans or 
pinnipeds transit the larger Level B harassment zone outside of the 
WRA.
    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 environmental conditions described 
for Hood Canal, 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 past 
projects at NBKB, 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. In response to 
vibratory driving, harbor seals (which may be somewhat habituated to 
human

[[Page 43164]]

activity along the NBKB waterfront) have been observed to orient 
towards and sometimes move towards the sound.
    For pinnipeds, no rookeries are present in the project area, there 
are no haul-outs other than those provided opportunistically by man-
made objects, and the project area is not known to provide foraging 
habitat of any special importance. No cetaceans are expected within the 
WRA. The pile driving activities analyzed here are similar to other 
nearby construction activities within the Hood Canal, including two 
recent projects conducted by the Navy at the same location (test pile 
project and EHW-1 pile replacement project) as well as work conducted 
in 2005 for the Hood Canal Bridge (SR-104) by the Washington Department 
of Transportation, which have taken place with no reported injuries or 
mortality to marine mammals, and no known long-term adverse 
consequences from behavioral harassment.
    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 cetaceans within 
the WRA and generally sporadic occurrence outside the WRA; (5) the 
absence of any other known areas or features of special significance 
for foraging or reproduction within the project area; (6) 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, with the exception of the Steller sea lion (eastern DPS 
only), none of these stocks are listed under the ESA or considered of 
special status (e.g., depleted or strategic) under the MMPA. Five of 
the stocks for which take is authorized, including the Steller sea 
lion, are thought to be increasing. Insufficient information is 
available to determine population trends for the sixth stock (Dall's 
porpoise). In combination, we believe that these factors, as well as 
the available body of evidence from other similar activities, including 
those conducted at the same time of year and in the same location, 
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

    No tribal subsistence hunts are held in the vicinity of the project 
area; thus, temporary behavioral impacts to individual animals will not 
affect any subsistence activity. Further, no population or stock level 
impacts to marine mammals are anticipated or authorized. As a result, 
no impacts to the availability of the species or stock to the Pacific 
Northwest treaty tribes are expected as a result of the activities. 
Therefore, no relevant subsistence uses of marine mammals are 
implicated by this action.

Endangered Species Act (ESA)

    There are two ESA-listed marine mammal species with known 
occurrence in the project area: the Eastern DPS of the Steller sea 
lion, listed as threatened, and the humpback whale, listed as 
endangered. Because of the potential presence of these species, the 
Navy engaged in a formal consultation with the NMFS Northwest Regional 
Office (NWR) under Section 7 of the ESA. We also initiated separate 
consultation with NWR because of our proposal to authorize the 
incidental take of Steller sea lions under the first IHA for EHW-2 
construction. NWR's Biological Opinion, issued on September 29, 2011, 
concluded that the effects of pile driving activities at NBKB were 
likely to adversely affect, but not likely to jeopardize the continued 
existence of the eastern DPS of Steller sea lion. The Steller sea lion 
does not have critical habitat in the action area. Subsequent to the 
completion of the biological opinion, NWR prepared an Incidental Take 
Statement (ITS) to be appended to the opinion.
    NWR compared the ITS, as well as the effects analysis and 
conclusions in the Biological Opinion, with the amount of and 
conditions on take proposed in the IHA and determined that the effects 
of issuing an IHA to the Navy for the taking of Steller sea lions 
incidental to construction activities are consistent with those 
described in the opinion. The September 29, 2011 Biological Opinion 
remains valid and the proposed MMPA authorization provided no new 
information about the effects of the action, nor did it change the 
extent of effects of the action, or any other basis to require 
reinitiation of the opinion. Therefore, the September 29, 2011 
Biological Opinion meets the requirements of section 7(a)(2) of the ESA 
and implementing regulations at 50 CFR 402 for both the Navy 
construction action, as well as our action to issue an IHA under the 
MMPA, and no further consultation is required. NWR has issued a new ITS 
and appended it to the 2011 Biological Opinion upon issuance of the 
IHA.

National Environmental Policy Act (NEPA)

    The Navy prepared an Environmental Impact Statement and issued a 
Record of Decision for this project. We acted as a cooperating agency 
in the preparation of that document, and reviewed the EIS and the 
public comments received and determined that preparation of additional 
NEPA analysis was not necessary. We subsequently adopted the Navy's EIS 
and issued our own Record of Decision for the issuance of the first IHA 
on July 6, 2012.
    We reviewed the Navy's application for a renewed IHA for ongoing 
construction activities for 2013-14 and the 2012-13 monitoring report. 
Based on that review, we determined that the action follows closely the 
previous IHA and does not present any substantial changes, or 
significant new circumstances or information relevant to environmental 
concerns which would require preparation of a new or supplemental NEPA 
document. Therefore, we have determined that a new or supplemental 
Environmental Assessment or EIS is unnecessary, and, after review of 
public comments, reaffirm our 2012 ROD. The 2012 NEPA documents are 
available for review at https://www.nmfs.noaa.gov/pr/permits/incidental.htm.

[[Page 43165]]

Authorization

    As a result of these determinations, we have issued an IHA to the 
Navy to conduct the described activities in the Hood Canal from the 
period of July 16, 2013, through February 15, 2014, provided the 
previously described mitigation, monitoring, and reporting requirements 
are incorporated.

    Dated: July 11, 2013.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2013-17404 Filed 7-18-13; 8:45 am]
BILLING CODE 3510-22-P