Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Barge Mooring Project, 43165-43180 [2013-17405]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 78, Number 139 (Friday, July 19, 2013)]
[Notices]
[Pages 43165-43180]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2013-17405]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XC647


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Barge Mooring Project

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

ACTION: Notice; issuance of an incidental harassment authorization.

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

DATES: This authorization is effective from July 16, 2013, through 
September 30, 2013.

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 
Assessment (2013) and our associated Finding of No Significant Impact, 
prepared pursuant to the National Environmental Policy Act, are also 
available at the same site. Documents cited in this notice may also be 
viewed, by appointment, during regular business hours, at the 
aforementioned address.

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

SUPPLEMENTARY INFORMATION: 

Background

    Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) 
direct the Secretary of Commerce to allow, upon request, the 
incidental, but not intentional, taking of small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, a notice of a proposed authorization is 
provided to the public for review.
    Authorization for incidental takings shall be granted if NMFS finds 
that the taking will have a negligible impact on the species or 
stock(s), will not have an unmitigable adverse impact on the 
availability of the species or stock(s) for subsistence uses (where 
relevant), and if the permissible methods of taking and requirements 
pertaining to the mitigation, monitoring and reporting of such takings 
are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 
as ``. . . an impact resulting from the specified activity that cannot 
be reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the U.S. can apply for an authorization to 
incidentally take small numbers of marine mammals by harassment. 
Section 101(a)(5)(D) establishes a 45-day time limit for NMFS review of 
an application followed by a 30-day public notice and comment period on 
any proposed authorizations for the incidental harassment of marine 
mammals. Within 45 days of the close of the comment period, NMFS must 
either issue or deny the authorization. Except with respect to certain 
activities not pertinent here, the MMPA defines ``harassment'' as: 
``Any act of pursuit, torment, or annoyance which (i) has the potential 
to injure a marine mammal or marine mammal stock in the wild [Level A 
harassment]; or (ii) has the potential to disturb a marine mammal or 
marine mammal stock in the wild by causing disruption of behavioral 
patterns, including, but not limited to, migration, breathing, nursing, 
breeding, feeding, or sheltering [Level B harassment].''

Summary of Request

    We received an application on February 6, 2013, from the Navy for 
the taking of marine mammals incidental to pile driving and removal in 
association with a barge mooring project in the Hood Canal at Naval 
Base Kitsap in Bangor, WA (NBKB). The Navy submitted a revised version 
of the application on April 8, 2013, which we deemed adequate and 
complete. The barge mooring project is expected to require 
approximately eight weeks and will occur between July 16 and September 
30, 2013. Four species of marine mammals are expected to be affected by 
the specified activities: California sea lion (Zalophus californianus 
californianus), harbor seal (Phoca vitulina richardii), harbor porpoise 
(Phocoena phocoena vomerina), and killer whale (transient only; Orcinus 
orca). These species may occur year-round in the Hood Canal, with the 
exception of the California sea lion, which is only present from late 
summer to late spring (August to early June).
    NBKB provides berthing and support services to Navy submarines and 
other fleet assets. Commander Submarine Development Squadron Five 
(CSDS-5) is a tenant command on NBKB and is the working repository for 
deep ocean technology and operational, at-sea application of that 
technology. CSDS-5 currently moors and operates a research barge at the 
Service Pier on NBKB and plans to install mooring for a new larger 
research barge equipped with upgraded technology necessary for 
continuing the Navy mission. CSDS-5 currently conducts research 
equipment operations from an existing 115-ft by 35-ft barge with a 4-ft 
draft that was constructed in 1940 and cannot accommodate the new 
research equipment. A new larger barge measuring 260 ft by 85 ft with a 
10-ft draft will replace the existing barge. Activities associated with 
the project include the removal of an existing mooring dolphin, the 
relocation and addition of floating pier sections, and the installation 
of up to twenty steel piles to support the barge, electrical 
transformer platform, and relocated pier sections (see Figures 1-2 and 
1-3 in the Navy's application). All steel piles will be driven with a 
vibratory hammer for their initial embedment depths and 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.,

[[Page 43166]]

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 a similar project conducted at NBKB to estimate 
potential marine mammal exposures. Predicted exposures are outlined 
later in this document. The calculations predict that only Level B 
harassments 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 1-1 and 2-1 in the Navy's 
application). The specified actions with the potential to cause 
harassment of marine mammals within the waterways adjacent to NBKB, 
under the MMPA, are vibratory and impact pile driving and removal of 
piles via vibratory driver associated with the barge mooring project. 
All in-water construction activities within the Hood Canal are only 
permitted during July 16-February 15 in order to protect spawning fish 
populations; however, the entire barge mooring project is scheduled to 
be completed by September 30, 2013. 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 30273; May 22, 2013; hereafter, the FR notice); please see that 
document or the Navy's application for more information.
    The project consists of three components: The relocation and 
addition to the Port Operations pier, the removal of existing 
infrastructure, and the installation of the CSDS-5 research barge 
mooring piles. The barge mooring project is expected to require 
approximately forty work days and will occur only between July 16 and 
September 30, 2013. Figures 2-2 and 2-3 of the Navy's application 
contain details of the project area and site plan. The project is 
expected to require the installation of sixteen hollow steel pipe 
piles, including four 20-in diameter piles, three 24-in diameter piles, 
five 36-in diameter piles, and four 48-in diameter piles. Although only 
four 48-in piles are expected to be necessary, we include an additional 
four 48-in piles (for a total of eight 48-in piles and twenty total 
piles) in the effects analysis in the event that contingency piles are 
required. The 48-in piles will be the primary mooring supports for the 
new barge. In addition, one 24-in diameter pile will be removed using 
vibratory pile driving equipment.
    The Navy expects that a maximum of four piles can be driven per 
day, although this total is unlikely to be reached due to various 
delays that may be expected during construction work. The total number 
of days for both extraction and installation are not likely to exceed 
twenty workdays. Piles will be installed using mainly vibratory pile 
driving, although some piles may require impact driving to ensure load 
bearing capacity (proofing) or if substrate conditions do not allow the 
pile to reach the specified tip elevation with a vibratory driver. When 
the impact driver is required, the Navy expects that 500 strikes will 
be necessary per pile, resulting in approximately 2,000 strikes per day 
under the maximum scenario. All piles driven with an impact hammer will 
be surrounded by a bubble curtain over the full water column to 
minimize in-water noise.

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 30273; May 22, 2013). Significant sound-producing 
in-water construction activities associated with the project include 
impact and vibratory pile driving.
    NMFS uses generic sound exposure thresholds to determine when an 
activity that produces sound might result in impacts to a marine mammal 
such that a take by harassment might occur. To date, no studies have 
been conducted that examine impacts to marine mammals from pile driving 
sounds from which empirical sound thresholds have been established. 
Current NMFS practice (in relation to the MMPA) regarding exposure of 
marine mammals to sound is that cetaceans and pinnipeds exposed to 
sound levels of 180 and 190 dB root mean square (rms; note that all 
underwater sound levels in this document are referenced to a pressure 
of 1 [micro]Pa) or above, respectively, are considered to have been 
taken by Level A (i.e., injurious) harassment, while behavioral 
harassment (Level B) is considered to have occurred when 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 [mu]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. On the basis of existing data regarding bubble 
curtain efficacy, as well as site-specific measurements from the Navy's 
2011 Test Pile Project (TPP; Illingworth & Rodkin, Inc., 2012), we have 
determined that 8 dB is a reasonable assumption regarding average SPL 
(rms) reduction. To avoid loss of attenuation from design and 
implementation errors, the Navy has required 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 30273; May 22, 2013) for a detailed description of the 
calculations and information used to estimate distances to relevant 
threshold levels.

[[Page 43167]]

Transmission loss, or the decrease in acoustic intensity as an acoustic 
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. The Navy previously 
conducted measurements for driving of steel piles at NBKB as part of 
the TPP (Illingworth & Rodkin, Inc., 2012), and we have determined that 
use of those values is appropriate to determine reasonable SPLs and 
their associated effects on marine mammals that are likely to result 
from pile driving at NBKB. During the TPP, SPLs from driving of 24-, 
36-, and 48-in piles by impact and vibratory hammers were measured. 
Because 20-in piles were not measured during the TPP, we use sound 
pressure levels from the 24-in piles as a conservative estimate. 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.
    Representative data for pile driving SPLs recorded from the TPP 
were presented in the FR notice (78 FR 30273; May 22, 2013). Because it 
is unknown what size pile may be driven on any given day, the most 
conservative values (i.e., highest) were used, with practical spreading 
loss, to estimate distances to relevant thresholds. For impact pile 
driving, distances to the marine mammal sound thresholds were 
calculated with the assumption of an 8 dB reduction in source levels 
from the use of a bubble curtain. Source values (at 10 m) used for 
calculations were 188 dB for impact driving (196 dB as a representative 
value, less 8 dB of sound attenuation from use of a bubble curtain) and 
172 dB for vibratory driving. For airborne sound during the TPP, 
vibratory driving was measured at 102 dB and impact driving at 109 dB 
(both at 15 m). These values were used, with spherical spreading loss, 
to estimate distances to relevant thresholds. All calculated distances 
to and the total area encompassed by the marine mammal sound thresholds 
are provided in Tables 1 and 2. Predicted distances to thresholds for 
different sources are shown in Figures 6-1 through 6-4 of the Navy's 
application.

                   Table 1--Distances to Relevant Sound Thresholds and Areas of Ensonification
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                                                 Distance to threshold (m) and associated area of ensonification
                                    Effective                                (km\2\)
          Description             source level  ----------------------------------------------------------------
                                  (dB at 10 m)       190 dB          180 dB          160 dB           120 dB
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Steel piles, impact............             188       7, 0.0002      34, 0.0036      736, 1.702              n/a
Steel piles, vibratory.........             172      1, <0.0001      3, <0.0001             n/a      \1\ 29,286,
                                                                                                            16.1
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\1\ This distance cannot actually be attained at the project location. The area presented is actual.


           Table 2--Distances to Relevant Sound Thresholds and Areas of Ensonification, Airborne Sound
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                                                                                   Distance to threshold (m) and
                                                                                        associated area of
                                                                   Threshold, re      ensonification (km\2\)
                              Group                                20 [mu]Pa rms -------------------------------
                                                                   (unweighted)                      Vibratory
                                                                                  Impact driving      driving
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Harbor seals....................................................           90 dB     134, 0.0564      60, 0.0113
California sea lions............................................          100 dB      42, 0.0055      19, 0.0011
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    There are no haul-out locations within the airborne harassment 
zones, which are encompassed by the zones estimated for underwater 
sound. Protective measures will be in place out to the distances 
calculated for the underwater thresholds, and the distances for the 
airborne thresholds will be covered fully by mitigation and monitoring 
measures in place for underwater sound thresholds. 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.

Comments and Responses

    We published a notice of receipt of the Navy's application and 
proposed IHA in the Federal Register on May 22, 2013 (78 FR 30273). 
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 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 methodology 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

[[Page 43168]]

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\.
    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 30273; May 22, 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''. For example, during the first year of 
construction for the second explosives handling wharf (EHW-2; a 
separate action occurring at NBKB), 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 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

[[Page 43169]]

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 30273; May 22, 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 shutdown zones are small, with radial 
distances of only 10 m and 36 m for the 190- and 180-dB zones, 
respectively, while the 180 dB zone for cetaceans 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 10 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 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 
1.91.6 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,

[[Page 43170]]

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 throughout Hood Canal 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 an acceptable 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 
this project, as observers monitoring the concurrent EHW-2 project 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 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 EHW-2 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

[[Page 43171]]

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 Assessment prepared for this action, as well as in the 
NEPA analyses and biological opinions 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 concurrent 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 project. 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 (Phocoenoides dalli dalli), Steller sea lion 
(eastern stock only; Eumetopias jubatus monteriensis), California sea 
lion, harbor seal, and humpback whale (Megaptera novaeangliae). 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 30273; May 22, 
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 30273; May 22, 2013) provides a detailed description of 
marine mammal hearing and of the potential effects of these 
construction activities on marine mammals.

Anticipated Effects on Habitat

    The planned 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 barge mooring project. The FR notice (78 
FR 30273; May 22, 2013) describes these potential impacts in greater 
detail.

Mitigation

    In order to issue an incidental take authorization (ITA) under 
Section 101(a)(5)(D) of the MMPA, we must, 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

[[Page 43172]]

significance, and on the availability of such species or stock for 
taking for certain subsistence uses (where relevant).
    Measurements from similar pile driving elsewhere at NBKB 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 will occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area), thus preventing 
injury, serious injury, or death of marine mammals. Radial distances 
for shutdown zones are shown in Table 1. However, a minimum shutdown 
zone of 10 m will be established during all pile driving and removal 
activities, regardless of the estimated zone. These precautionary 
measures are intended to prevent the already unlikely possibility of 
physical interaction with construction equipment and to further reduce 
any possibility of acoustic injury.
    Disturbance Zone--Disturbance zones are 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 Tables 1 and 2. Given the size of the disturbance zone for vibratory 
pile driving, it is impossible to guarantee that all animals will 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 waterfront 
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 will be conducted before, during, 
and after pile driving activities. In addition, observers shall record 
all incidences of marine mammal occurrence, regardless of distance from 
activity, and shall document any behavioral reactions in concert with 
distance from piles being driven. Observations made outside the 
shutdown zone will not result in shutdown; that pile segment will 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 30 minutes post-completion of pile driving activities. Pile 
driving activities include the time to remove a single pile or series 
of piles, as long as the time elapsed between uses of the pile driving 
equipment is no more than 30 minutes. 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);

[[Page 43173]]

     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 timing restrictions exist 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 barge mooring project will occur during a 
portion of that period, from July 16-September 30. During the majority 
of this timeframe, 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, 
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 30273; May 22, 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 proposed action area. Please see the Navy's Marine 
Mammal Monitoring Plan for

[[Page 43174]]

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 Navy will 
implement the following procedures for pile driving:
     MMOs will be located at the best vantage point(s) in order 
to properly see the entire shutdown zone and as much of the disturbance 
zone as possible.
     During all observation periods, observers will use 
binoculars and the naked eye to search continuously for marine mammals.
     If the shutdown zones are obscured by fog or poor lighting 
conditions, pile driving at that location will not be initiated until 
that zone is visible. Should such conditions arise while impact driving 
is underway, the activity will be halted.
     The shutdown and disturbance zones around the pile will be 
monitored for the presence of marine mammals before, during, and after 
any pile driving or removal activity.
    Individuals implementing the monitoring protocol will assess its 
effectiveness using an adaptive approach. Monitoring biologists will 
use their best professional judgment throughout implementation and seek 
improvements to these methods when deemed appropriate. Any 
modifications to protocol will be coordinated between NMFS and the 
Navy.

Data Collection

    We require that observers use approved data forms. Among other 
pieces of information, the Navy will record detailed information about 
any implementation of shutdowns, including the distance of animals to 
the pile and description of specific actions that ensued and resulting 
behavior of the animal, if any. In addition, the Navy will attempt to 
distinguish between the number of individual animals taken and the 
number of incidences of take. We require that, at a minimum, the 
following information be collected on the sighting forms:
     Date and time that monitored activity begins or ends;
     Construction activities occurring during each observation 
period;
     Weather parameters (e.g., percent cover, visibility);
     Water conditions (e.g., sea state, tide state);
     Species, numbers, and, if possible, sex and age class of 
marine mammals;
     Description of any observable marine mammal behavior 
patterns, including bearing and direction of travel, and if possible, 
the correlation to SPLs;
     Distance from pile driving activities to marine mammals 
and distance from the marine mammals to the observation point;
     Locations of all marine mammal observations; and
     Other human activity in the area.

Reporting

    A draft report will be submitted to NMFS within 90 working days of 
the completion of marine mammal monitoring. The report will include 
marine mammal observations pre-activity, during-activity, and post-
activity during pile driving days, and will also provide descriptions 
of any adverse responses to construction activities by marine mammals 
and a complete description of all mitigation shutdowns and the results 
of those actions and a refined take estimate based on the number of 
marine mammals observed during the course of construction. A final 
report will be prepared and 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, 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 incidental taking of 
small numbers of California sea lions, harbor

[[Page 43175]]

seals, transient killer whales, and harbor porpoises in the Hood Canal 
that may result from pile driving during construction activities 
associated with the barge mooring project described previously in this 
document.
    The humpback whale is not expected to occur in the project area, 
and Steller sea lions are not expected to occur during the project 
timeframe. The earliest documented occurrence of Steller sea lions at 
NBKB occurred on September 30, 2010, when five individuals were 
observed at Delta Pier during daily surveys. During monitoring 
associated with the 2011 TPP, Steller sea lions were documented as 
arriving on October 8, but had not previously been regularly observed 
prior to November.

Marine Mammal Densities

    For all species, the best scientific information available was used 
to derive density estimates and the maximum appropriate density value 
for each species for each site was used in the marine mammal take 
assessment calculation. These values were derived or confirmed by 
experts convened to develop such information for use in Navy 
environmental compliance efforts in the Pacific Northwest (Navy, 2013). 
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). 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 in this IHA, and these data provide the 
basis for take estimation for California sea lions. Please note that, 
although we erroneously stated in the FR notice that data were compiled 
only through November 2011, the data actually displayed in Table 6 of 
that document was indeed compiled through December 2012. Other 
information, including sightings data from other Navy survey efforts at 
NBKB, is available for this 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 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 in this proposed 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 California sea lion does 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).

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 formula was developed for calculating take due to pile driving 
activity and applied to each group-specific sound impact threshold. The 
formula is founded on the following assumptions:

[[Page 43176]]

     Mitigation measures (e.g., bubble curtain) will be 
utilized, as discussed previously;
     All marine mammal individuals potentially available are 
assumed to be present within the relevant area, and thus incidentally 
taken;
     An individual can only be taken once during a 24-h period; 
and,
     There were will be twenty total days of activity.
     Exposures to sound levels above the relevant thresholds 
equate to take, as defined by the MMPA.
    The calculation for marine mammal takes is estimated by:

Exposure estimate = (n * ZOI) * days of total activity

Where:
n = density estimate used for each species/season
ZOI = sound threshold ZOI impact area; the area encompassed by all 
locations where the SPLs equal or exceed the threshold being 
evaluated
n * ZOI produces an estimate of the abundance of animals that could 
be present in the area for exposure, and is rounded to the nearest 
whole number before multiplying by days of total activity.

    The ZOI impact area is the estimated range of impact to the sound 
criteria. The distances specified in Table 1 were used to calculate 
ZOIs around each pile. All impact pile driving take calculations were 
based on the estimated threshold ranges assuming attenuation of 8 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 will 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. The 
Service Pier is elevated at least twenty feet above the surface of the 
water and is inaccessible to pinnipeds, and seals have not been 
observed hauled out on the floating Port Operations pier sections or on 
the shoreline adjacent to the Service Pier. 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 will 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.
    California Sea Lion--California sea lions occur regularly in the 
vicinity of the project site from August through mid-June, as 
determined by Navy waterfront surveys conducted from April 2008 through 
December 2012 (Table 3). With regard to the range of this species in 
Hood Canal and the project area, it is assumed on the basis of 
waterfront observations (Agness and Tannenbaum, 2009; Tannenbaum et 
al., 2009, 2011) that the opportunity to haul out on submarines docked 
at Delta Pier is a primary attractant for California sea lions in Hood 
Canal, as they are not typically observed elsewhere in Hood Canal. 
Their haul-out sites are not within the largest underwater ZOI, because 
sound will encounter land before reaching the haul-out site (see Figure 
6-2 in the Navy's application). Abundance is calculated as the monthly 
average of the maximum number observed in a given month, as opposed to 
the overall average (Table 3). That is, the maximum number of animals 
observed on any one day in a given month was averaged for 2008-12, 
providing a monthly average of the maximum daily number observed. The 
largest monthly average (58 animals) was recorded in November, as was 
the largest single daily count (81 in 2011). The first California sea 
lion was observed at NBKB in August 2009, and their occurrence has been 
increasing since that time (Navy, 2012).
    California sea lion density for Hood Canal was calculated to be 
0.28 animals/km\2\ for purposes of the Navy Marine Species Density 
Database (Navy, 2013). However, this density was derived by averaging 
data collected year-round. This project will occur during the months 
when California sea lions are the least abundant in Hood Canal, so it 
is more appropriate to use data collected at the NBKB waterfront during 
those months (August-September; we exclude July because it is likely 
that the majority of work will occur in August and September). In 
addition, local observations show that sea lions are attracted to haul-
out opportunities at NBKB, resulting in greater local abundance than is 
indicated by the NMSDD density value. In our analysis contained in the 
FR notice (78 FR 30273; May 22, 2013), and based on the Navy's request 
for take authorization, we considered the highest number of individual 
California sea lions observed hauled out at NBKB during the July-
September timeframe (i.e., 33), which occurred at the end of September 
2010. Exposures were calculated assuming 33 individuals could be 
present, and therefore exposed to sound exceeding the behavioral 
harassment threshold, on each day of pile driving. We noted in that 
document that this was an extremely conservative methodology, but chose 
to carry it forward. However, in subsequent discussions with the Marine 
Mammal Commission, we determined that this conservative

[[Page 43177]]

methodology was likely unwarranted and resulted in unrealistic take 
estimates (i.e., a much greater take estimate for California sea lions 
than for harbor seals), given the observed primacy of harbor seals in 
waterfront observations for other actions at NBKB. Therefore, we have 
determined that it is more appropriate to use the monthly average from 
August-September, which considers the much lower observed abundances 
from August and early September (when the majority of project activity 
is likely to be completed). We still conservatively assume that all 
individuals potentially present (i.e., seven individuals; see Table 3) 
will be taken on any given day of activity.

              Table 3--California Sea Lion Sighting Information From NBKB, April 2008-December 2012
----------------------------------------------------------------------------------------------------------------
                                                                     Number of
                                                     Number of     surveys with    Frequency of
                      Month                           surveys         animals      presence \1\    Abundance \2\
                                                                      present
----------------------------------------------------------------------------------------------------------------
January.........................................              47              36           0.77             31.0
February........................................              50              43           0.86             38.0
March...........................................              47              45           0.96             53.3
April...........................................              67              55           0.82             45.4
May.............................................              72              58           0.81             29.4
June............................................              73              17           0.23              7.4
July............................................              61               1           0.02              0.6
August..........................................              65              12           0.18              2.6
September.......................................              54              31           0.57             20.4
October.........................................              65              61           0.94             51.8
November........................................              56              56           1                60.2
December........................................              54              44           0.81             49.6
                                                 ---------------------------------------------------------------
    Total or average (Aug-Sep only).............             119              43           0.36             10.7
----------------------------------------------------------------------------------------------------------------
Totals (number of surveys) and averages (frequency and abundance) presented for project period (August-
  September) only. Information from other months presented for reference. Average abundance is weighted by
  monthly survey effort.
\1\ Frequency is the number of surveys with California sea lions present/number of surveys conducted.
\2\ Abundance is calculated as the monthly average of the maximum daily number observed in a given month.

    Harbor Seal--Jeffries et al. (2003) conducted aerial surveys of the 
harbor seal population in Hood Canal in 1999 for the Washington 
Department of Fish and Wildlife and reported 711 harbor seals hauled 
out. The authors adjusted this abundance with a correction factor of 
1.53 to account for seals in the water, which were not counted, and 
estimated that there were 1,088 harbor seals in Hood Canal. The 
correction factor (1.53) was based on the proportion of time seals 
spend on land versus in the water over the course of a day, and was 
derived by dividing one by the percentage of time harbor seals spent on 
land. These data came from tags (VHF transmitters) applied to harbor 
seals at six areas (Grays Harbor, Tillamook Bay, Umpqua River, Gertrude 
Island, Protection/Smith Islands, and Boundary Bay, BC) within two 
different harbor seal stocks (the coastal stock and the inland waters 
of WA stock) over four survey years. The Hood Canal population is part 
of the inland waters stock, and while not specifically sampled, 
Jeffries et al. (2003) found the VHF data to be broadly applicable to 
the entire stock. The tagging research in 1991 and 1992 conducted by 
Huber et al. (2001) and Jeffries et al. (2003) used the same methods 
for the 1999 and 2000 survey years. These surveys indicated that 
approximately 35 percent of harbor seals are in the water versus hauled 
out on a daily basis (Huber et al., 2001; Jeffries et al., 2003). 
Exposures were calculated using a density derived from the number of 
harbor seals that are present in the water at any one time (35 percent 
of 1,088, or approximately 381 individuals), divided by the area of the 
Hood Canal (358.44 km\2\) and the formula presented previously. The 
aforementioned area of Hood Canal represents a change from that cited 
previously for authorizations associated with Navy activities in Hood 
Canal, and represents a correction to our understanding of the 
methodology used in Jeffries et al. (2003).
    We recognize that over the course of the day, while the proportion 
of animals in the water may not vary significantly, different 
individuals may enter and exit the water. However, fine-scale data on 
harbor seal movements within the project area on time durations of less 
than a day are not available. Previous monitoring experience from Navy 
actions conducted from in the same project area has indicated that this 
density provides an appropriate estimate of potential exposures. 
However, the density of harbor seals calculated in this manner (1.06 
animals/km\2\) is corroborated by results of the Navy's vessel-based 
marine mammal surveys at NBKB in 2008 and 2009-10, in which an average 
of five individual harbor seals per survey was observed in the 3.9 
km\2\ survey area (density = 1.3 animals/km\2\) (Tannenbaum et al., 
2009, 2011).
    Killer Whales--Transient killer whales are uncommon visitors to 
Hood Canal, and may be present anytime during the year. Transient pods 
(six to eleven individuals per event) were observed in Hood Canal for 
lengthy periods of time (59-172 days) in 2003 (January-March) and 2005 
(February-June), feeding on harbor seals (London, 2006). These whales 
used the entire expanse of Hood Canal for feeding. West Coast transient 
killer whales most often travel in small pods (Baird and Dill 1996). 
Houghton reported to the Navy, from unpublished data, that the most 
commonly observed group size in Puget Sound (defined as from Admiralty 
Inlet south and up through Skagit Bay) from 2004-2010 data is six 
whales.
    The density value derived for the Navy Marine Species Density 
Database is 0.0019 animals/km\2\ (Navy, 2013), which would result in a 
prediction that zero animals will be harassed by the project 
activities. However, while transient killer whales are rare in the Hood 
Canal, it is possible that a pod of animals could be present. In the 
event that this occurred, the animals would not assume a uniform 
distribution as is implied by the density estimate. Therefore, we 
conservatively assume that a single pod of whales (defined as six 
whales) could be present in the

[[Page 43178]]

vicinity of the project for the entire duration.

Dall's Porpoise

    Dall's porpoises may be present in the Hood Canal year-round and 
could occur as far south as the project site. Their use of inland 
Washington waters, however, is mostly limited to the Strait of Juan de 
Fuca. One individual has been observed by Navy staff in deeper waters 
of Hood Canal (Tannenbaum et al., 2009, 2011). The Navy Marine Species 
Density Database assumes a negligible value of 0.001 animals/1,000 
km\2\ for Dall's porpoises in the Hood Canal, which represents species 
that have historically been observed in an area but have no regular 
presence. Use of this density value results in a prediction that zero 
animals will be exposed to sound above the behavioral harassment 
threshold, and the Navy has not requested any take authorization for 
Dall's porpoises.

Harbor Porpoise

    During vessel-based line transect surveys on non-construction days 
during the TPP, harbor porpoises were frequently sighted within several 
kilometers of the base, mostly to the north or south of the project 
area, but occasionally directly across from the Bangor waterfront on 
the far side of Toandos Peninsula. Harbor porpoise presence in the 
immediate vicinity of the base (i.e., within 1 km) remained low. These 
data were used to generate a density for Hood Canal. Based on guidance 
from other line transect surveys conducted for harbor porpoises using 
similar monitoring parameters (e.g., boat speed, number of observers) 
(Barlow, 1988; Calambokidis et al., 1993; Caretta et al., 2001), the 
Navy determined the effective strip width for the surveys to be one 
kilometer, or a perpendicular distance of 500 m from the transect to 
the left or right of the vessel. The effective strip width was set at 
the distance at which the detection probability for harbor porpoises 
was equivalent to one, which assumes that all individuals on a transect 
are detected. Only sightings occurring within the effective strip width 
were used in the density calculation. By multiplying the trackline 
length of the surveys by the effective strip width, the total area 
surveyed during the surveys was 471.2 km\2\. Thirty-eight individual 
harbor porpoises were sighted within this area, resulting in a density 
of 0.0806 animals per km\2\. To account for availability bias, or the 
animals which are unavailable to be detected because they are 
submerged, the Navy utilized a g(0) value of 0.54, derived from other 
similar line transect surveys (Barlow, 1988; Calambokidis et al., 1993; 
Carretta et al., 2001). This resulted in a corrected density of 0.149 
harbor porpoises per km\2\. For comparison, 274.27 km\2\ of trackline 
survey effort in nearby Dabob Bay produced a corrected density estimate 
of 0.203 harbor porpoises per km\2\.

     Table 4--Number of Potential Incidental Takes of Marine Mammals Within Various Acoustic Threshold Zones
----------------------------------------------------------------------------------------------------------------
                                                                            Underwater
                                                                 --------------------------------
                                                                                     Vibratory         Total
                     Species                          Density      Impact injury    disturbance     authorized
                                                                   threshold \1\     threshold         takes
                                                                                   (120 dB) \2\
----------------------------------------------------------------------------------------------------------------
California sea lion.............................    \4\ 0.28                   0             220             220
Harbor seal.....................................        1.06                   0             340             340
Killer whale....................................    \5\ 0.0019                 0             120             120
Dall's porpoise.................................        0.000001               0               0               0
Harbor porpoise.................................        0.149                  0              40              40
----------------------------------------------------------------------------------------------------------------
\1\ Acoustic injury threshold for impact pile driving is 190 dB for pinnipeds and 180 dB for cetaceans.
\2\ Impact pile driving will always occur on the same day as vibratory pile driving, and the 160-dB acoustic
  harassment zone associated with impact pile driving is considered subsumed by the 120-dB harassment zone
  produced by vibratory driving. Therefore, takes are not calculated separately for the two zones.
\4\ A maximum abundance estimate of 11 animals present per day during the project timeframe was used for take
  estimation.
\5\ Here we assume that a single pod of transient killer whales (defined as six whales) may be present for the
  duration of the work period (twenty days).

Negligible Impact and Small Numbers Analysis and Determinations

    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``. . . 
an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.'' In making a negligible impact determination, 
NMFS considers a variety of factors, including but not limited to: (1) 
The number of anticipated mortalities; (2) the number and nature of 
anticipated injuries; (3) the number, nature, intensity, and duration 
of Level B harassment; and (4) the context in which the take occurs.

Small Numbers Analysis

    The proposed numbers of animals authorized to be taken for 
California sea lions, harbor seals, and harbor porpoise would be 
considered small relative to the relevant stocks or populations (less 
than one percent for California sea lions and harbor porpoise and less 
than three percent for harbor seals) even if each estimated taking 
occurred to a new individual--an extremely unlikely scenario, as, for 
pinnipeds occurring at the NBKB waterfront, there will almost certainly 
be some overlap in individuals present day-to-day. Further, for the 
pinniped species, these takes could potentially occur only within some 
small portion of the overall regional stock. 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

[[Page 43179]]

waters stock as a whole. 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. 
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 barge mooring project, 
as outlined previously, have the potential to disturb or displace 
marine mammals. Specifically, the proposed 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 north 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 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, none of these stocks are listed under the ESA or considered 
of special status (e.g., depleted or strategic) under the MMPA, and all 
four are thought to be increasing. 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

    While the number of marine mammals potentially incidentally 
harassed will depend on the distribution and abundance of marine 
mammals in the vicinity of the survey activity, we find that the number 
of potential takings, by level B harassment only, 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.

[[Page 43180]]

Endangered Species Act (ESA)

    There are no ESA-listed marine mammals expected to occur in the 
action area during the proposed action timeframe; therefore, no 
consultation under the ESA is required for such species.

National Environmental Policy Act (NEPA)

    In compliance with the National Environmental Policy Act of 1969 
(42 U.S.C. 4321 et seq.), as implemented by the regulations published 
by the Council on Environmental Quality (40 CFR parts 1500-1508), the 
Navy prepared an Environmental Assessment (EA) to consider the direct, 
indirect and cumulative effects to the human environment resulting from 
the barge mooring project. NMFS made the Navy's EA available to the 
public for review and comment, in relation to its suitability for 
adoption by NMFS in order to assess the impacts to the human 
environment of issuance of an IHA to the Navy. Also in compliance with 
NEPA and the CEQ regulations, as well as NOAA Administrative Order 216-
6, NMFS has reviewed the Navy's EA, determined it to be sufficient, and 
adopted that EA and signed a Finding of No Significant Impact (FONSI) 
on July 3, 2013. The Navy's EA and NMFS' FONSI for this action may be 
found at https://www.nmfs.noaa.gov/pr/permits/incidental.htm.

Authorization

    As a result of these determinations, we have issued an IHA to the 
Navy to conduct the described activities in the Hood Canal from the 
period of July 16, 2013, through September 30, 2013, provided the 
previously described mitigation, monitoring, and reporting requirements 
are incorporated.

    Dated: July 10, 2013.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2013-17405 Filed 7-18-13; 8:45 am]
BILLING CODE 3510-22-P