[Federal Register Volume 77, Number 141 (Monday, July 23, 2012)]
[Notices]
[Pages 43049-43063]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-17638]


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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XB146


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Pile Replacement Project

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

ACTION: Notice; issuance of an incidental harassment authorization.

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

DATES: This authorization is effective from July 16, 2012, through 
February 15, 2013.

[[Page 43050]]


ADDRESSES: A copy of the IHA and related documents are available 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 copy of the application, including references used in this 
document, may be obtained by visiting the Internet at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. For those members of the 
public unable to view these documents on the Internet, a copy may be 
obtained by writing to the address specified above or telephoning the 
contact listed below (see FOR FURTHER INFORMATION CONTACT). The Navy's 
Environmental Assessment (2011) and Supplemental EA (2012) 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 we find 
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. We have 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 our 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, we 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 March 8, 2012, from the Navy for the 
taking of marine mammals incidental to pile removal in association with 
a pile replacement project in the Hood Canal at Naval Base Kitsap at 
Bangor, WA (NBKB). This pile replacement project will occur during the 
designated in-water work window for Hood Canal, between July 16, 2012 
and February 15, 2013. The issued IHA covers the second and final year 
of this project; we previously issued an IHA for the first year of work 
associated with this project (76 FR 30130; May 24, 2011). Seven species 
of marine mammals are known from the waters surrounding NBKB, including 
the Steller sea lion (Eumetopias jubatus), California sea lion 
(Zalophus californianus), harbor seal (Phoca vitulina), killer whale 
(Orcinus orca; transient type only), Dall's porpoise (Phocoenoides 
dalli), harbor porpoise (Phocoena phocoena), and humpback whale 
(Megaptera novaeangliae). These species may occur year-round in the 
Hood Canal, with the exception of the Steller sea lion, which is 
present only from fall to late spring (October to mid-April), and the 
California sea lion, which is not present during part of summer (late 
June through July). Additionally, while the Southern resident killer 
whale (listed as endangered under the Endangered Species Act [ESA]) is 
resident to the inland waters of Washington and British Columbia, it 
has not been observed in the Hood Canal in over 15 years and was 
therefore excluded from further analysis.
    NBKB provides berthing and support services for OHIO Class 
ballistic missile submarines (SSBN), also known as TRIDENT submarines. 
The Navy's pile replacement project is necessary to complete repairs at 
the Explosive Handling Wharf 1 (EHW-1) facility at NBKB in 
order to to restore and maintain the structural integrity of the wharf 
and ensure its continued functionality to support necessary operational 
requirements. The EHW-1 facility, constructed in 1977, has become 
compromised due to the deterioration of the wharf's existing piling 
sub-structure. The planned activities include removal of ninety-six 24-
in (0.6-m) diameter concrete piles, twenty-one 12-in (0.3-m) diameter 
steel fender piles, and eight 16-in (0.4-m) diameter steel falsework 
piles, and represent the remainder of work planned for the initial 2-
year rehabilitation plan. The Navy is likely to continue rehabilitation 
work at EHW-1 in the long-term, but has no immediate plans to do so. 
All concrete piles would be removed via pneumatic chipping or similar 
method. All steel piles would be removed via vibratory hammer, direct 
pull, or, if necessary, cut off at the mud line; however, the analysis 
in this document assumes that all piles would be removed via vibratory 
hammer. No pile installation--and therefore no impact pile removal--
will occur.
    For pile removal activities, the Navy used our current thresholds 
for assessing impacts (NMFS, 2005, 2009), outlined later in this 
document. The Navy used recommended spreading loss formulas (the 
practical spreading loss equation for underwater sounds and the 
spherical spreading loss equation for airborne sounds) and empirically-
measured source levels from 18- to 30-in (0.5- to 0.8-m) diameter steel 
pile removal events, or concrete pile removal events using similar 
methodology, to estimate potential marine mammal exposures. Predicted 
exposures are outlined later in this document. The calculations predict 
that no Level A harassments would occur associated with pile removal 
activities, and that as many as 1,416 Level B harassments may occur 
during the pile replacement project from generation of underwater 
sound. No incidents of harassment were predicted from airborne sounds 
associated with pile removal.

Description of the Specified Activity

    NBKB is located on the Hood Canal approximately 20 miles (32 km) 
west of Seattle, Washington (see Figures 2-1 through 2-3 in the Navy's 
application). NBKB provides berthing and support services for OHIO 
Class ballistic missile

[[Page 43051]]

submarines (SSBN), also known as TRIDENT submarines. The Navy's pile 
replacement project is designed to maintain the structural integrity of 
EHW-1 and ensure its continued functionality to support operational 
requirements of the TRIDENT submarine program. Construction activities 
with the potential to cause harassment of marine mammals within the 
waterways adjacent to NBKB, under the MMPA, are vibratory and pneumatic 
chipping pile removal operations associated with the pile replacement 
project. These activities will occur between July 16, 2012 and February 
15, 2013; all in-water construction activities within the Hood Canal 
are only permitted during July 16-February 15 in order to protect 
spawning fish populations.
    As part of the Navy's sea-based strategic deterrence mission, the 
Navy Strategic Systems Programs directs research, development, 
manufacturing, test, evaluation, and operational support for the 
TRIDENT Fleet Ballistic Missile program. Maintenance and development of 
necessary facilities for handling of explosive materials is part of 
these duties. The Navy's repair project includes the removal of 126 
steel and concrete piles at EHW-1. Please see Figures 1-1 through 1-3 
of the Navy's application for conceptual and schematic representations 
of the work proposed for EHW-1. Of the piles requiring removal, 96 are 
24-in (0.6-m) diameter hollow pre-cast concrete piles which will be 
excised down to the mud line. Twenty-one 12-in (0.3-m) steel fender 
piles and eight 16-in (0.4-m) steel falsework piles will be extracted 
using a vibratory hammer or direct pull, and one additional 24-in steel 
fender pile will be extracted via direct pull only. Also included in 
the repair work is removal of the fragmentation barrier and walkway, 
construction of new cast-in-place pile caps (concrete formwork may be 
located below Mean Higher High Water [MHHW]), installation of the pre-
stressed superstructure, installation of four sled-mounted cathodic 
protection (CP) systems, and installation or re-installation of related 
appurtenances.
    Work completed at EHW-1 during the first year of work, conducted 
under an IHA issued by us (76 FR 30130; May 24, 2011), was described in 
the notice of receipt of Navy's application and request for comments on 
the proposed IHA that was published in the Federal Register (hereafter, 
`the FR notice'; 77 FR 25408; April 30, 2012). In addition, the work 
proposed by the Navy and scheduled for completion under the current IHA 
was described in detail. Please see that document for more information 
on the Navy's planned and completed construction activities.
    The Navy estimates that steel pile removal will occur at an average 
rate of two piles per day and that concrete pile removal will occur at 
a rate of three piles per day. These two activities would likely not 
occur on the same day, however. On the basis of these estimates, the 
Navy states that steel pile removal would require 15 days and concrete 
pile removal would require an additional 32 days. Our analysis is thus 
based upon these numbers, and assumes that (1) all marine mammals 
available to be incidentally taken within the relevant area would be; 
and (2) individual marine mammals may only be incidentally taken once 
in a 24-hour period--for purposes of authorizing specified numbers of 
take--regardless of actual number of exposures in that period.

Description of Sound Sources and Distances to Thresholds

    An in-depth description of sound sources in general was provided in 
the FR notice (77 FR 25408; April 30, 2012). Significant sound-
producing in-water construction activities associated with the project 
include vibratory pile removal and pneumatic chipping of concrete 
piles.
    Since 1997, we have used generic sound exposure thresholds as 
guidelines to estimate when harassment may occur. Current practice 
regarding exposure of marine mammals to sound defines thresholds as 
follows: 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 the EHW-1 activities) and 160 dB rms for pulsed sound, but below 
injurious thresholds. For airborne sound, pinniped disturbance from 
haul-outs has been documented at 100 dB (unweighted) for pinnipeds in 
general, and at 90 dB (unweighted) for harbor seals (note that all 
airborne sound levels in this document are referenced to a pressure of 
20 [micro]Pa).

Distance to Sound Thresholds

    Pile removal generates underwater noise that could potentially 
result in disturbance to marine mammals in the project area. Please see 
the FR notice for a detailed description of the calculations and 
information used to estimate distances to relevant threshold levels. 
Transmission loss, or the decrease in acoustic intensity as an acoustic 
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 removal sounds is greatly influenced by 
factors such as the type of piles, hammers, and the physical 
environment in which the activity takes place. Despite a large quantity 
of literature regarding SPLs recorded from in-water construction 
projects, there is a general lack of empirical data regarding vibratory 
pile removal and the acoustic output of chipping hammers. In order to 
determine reasonable SPLs and their associated affects on marine 
mammals that are likely to result from pile removal at NBKB, studies 
with similar properties to the Navy's project were evaluated. Overall, 
studies which met the following parameters were considered: (1) Pile 
size and materials: Steel pipe pile removal (12- to 24-in diameter) and 
concrete pile removal with chipping hammer or similar method (because 
these tools are used to chip portions of concrete from the pile, sound 
output is not tied to pile size); (2) Hammer machinery: Vibratory 
hammer for steel piles and pneumatic chipping hammer or similar tool 
for concrete piles; and (3) Physical environment: shallow depth (less 
than 30 m).
    Based on studies satisfying these parameters, the Navy determined 
that representative source levels (standardized to 1 m distance from 
the source) would be 180 dB rms for vibratory removal and 161 dB rms 
for pneumatic chipping. The estimated source level for vibratory 
removal is below the injury threshold for pinnipeds, while SPLs 
resulting from pneumatic chipping are well below levels that may cause 
injury to any marine mammal. These values represent reasonable SPLs 
which could be anticipated, and which were used in the acoustic 
modeling and analysis. All calculated distances to and the total area 
encompassed by the marine mammal underwater sound thresholds are 
provided in Table 1.

[[Page 43052]]



  Table 1--Calculated Distance(s) to and Area Encompassed by Underwater
                     Marine Mammal Sound Thresholds
------------------------------------------------------------------------
                Threshold                  Distance (m)    Area (km\2\)
------------------------------------------------------------------------
Vibratory removal, cetacean injury (180                1         < 0.001
 dB)....................................
Vibratory removal, disturbance (120 dB).          10,000             314
Pneumatic chipping, disturbance (120 dB)             542             0.9
------------------------------------------------------------------------

    The values presented in Table 1 assume a field free of obstruction, 
which is unrealistic, because Hood Canal does not represent open water 
conditions. Instead, sounds attenuate as they encounter land masses or 
bends in the canal. As a result, some of the distances and areas of 
impact calculated cannot actually be attained at the project area. The 
actual distances and areas for behavioral disturbance thresholds for 
vibratory pile removal and pneumatic chipping may be shorter and/or 
smaller than those calculated due to the irregular contour of the 
waterfront, the narrowness of the canal, and the maximum fetch 
(furthest distance sound waves travel without obstruction [i.e., line 
of sight]) at the project area. The actual areas encompassed by sound 
exceeding or reaching the 120 dB threshold are 35.9 km\2\ and 0.6 km\2\ 
for vibratory removal and pneumatic chipping, respectively. See Figures 
6-1 and 6-2 of the Navy's application for a depiction of the size of 
areas in which each underwater sound threshold is predicted to occur at 
the project area due to pile removal.
    Pile removal can generate airborne sound that could potentially 
result in disturbance to marine mammals (specifically, pinnipeds) which 
are hauled out or at the water's surface. As a result, the Navy 
analyzed the potential for pinnipeds hauled out or swimming at the 
surface near NBKB to be exposed to airborne SPLs that could result in 
Level B behavioral harassment. A spherical spreading loss model (i.e., 
6 dB reduction in sound level for each doubling of distance from the 
source), in which there is a perfectly unobstructed (free-field) 
environment not limited by depth or water surface, is appropriate for 
use with airborne sound and was used to estimate the distance to the 
airborne thresholds.
    As was discussed for underwater sound from pile removal, the 
intensity of pile removal sounds is greatly influenced by factors such 
as the type of piles, hammers, and the physical environment in which 
the activity takes place. In order to determine reasonable airborne 
SPLs and their associated effects on marine mammals that are likely to 
result from pile removal at NBKB, studies with similar properties to 
the Navy's project, as described previously, were evaluated. Evaluation 
of representative pile removal activities that have occurred in recent 
years, and which represent reasonable SPLs which could be anticipated, 
provide representative source levels of approximately 116.5 dB rms 
(unweighted) for vibratory removal and 112 dB rms (unweighted) for 
chipping. All calculated distances to and the total area encompassed by 
the marine mammal airborne sound thresholds are provided in Table 2.

   Table 2--Calculated Distance(s) to and Area Encompassed by Airborne
                     Marine Mammal Sound Thresholds
------------------------------------------------------------------------
                Threshold                  Distance (m)    Area (km\2\)
------------------------------------------------------------------------
Vibratory removal, pinniped disturbance                7         < 0.001
 (100 dB)...............................
Vibratory removal, harbor seal                        20           0.001
 disturbance (90 dB)....................
Pneumatic chipping, pinniped disturbance               4         < 0.001
 (100 dB)...............................
Pneumatic chipping, harbor seal                       13         < 0.001
 disturbance (90 dB)....................
------------------------------------------------------------------------

    Construction sound associated with the project would not extend 
beyond the disturbance zone for underwater sound that would be 
established to protect pinnipeds. No haul-outs or rookeries are located 
within the airborne harassment radii. It is important to note that 
animals within the harassment radii for airborne sound, even if they 
are in the water rather than hauled-out, may be exposed to SPLs that 
result in behavioral harassment when their heads are above water. 
However, these exposures are not considered separate `takes' for 
purposes of estimating total incidental take that may be caused by the 
project activities, as the animals would be previously exposed to 
underwater sound at or above levels that may result in behavioral 
harassment. See Figures 6-3 through 6-6 of the Navy's application for a 
depiction of the size of areas in which each airborne sound threshold 
is predicted to occur at the project area due to pile removal.

Acoustic Monitoring

    In 2011, the Navy conducted acoustic monitoring as required by IHAs 
for the first year of repair work at EHW-1 and for a test pile project 
(76 FR 25408; June 30, 2011) conducted in order to obtain geotechnical 
data in advance of the construction of a second EHW. The two projects 
together involved impact driving of 24 to 48-in piles, vibratory 
installation of 16 to 48-in piles, and vibratory removal of 12 to 48-in 
piles. All piles were steel pipe piles. Primary objectives for the 
acoustic monitoring were to characterize underwater and airborne source 
levels for each pile size and hammer type and to verify distances to 
relevant threshold levels by characterizing site-specific transmission 
loss. Secondary objectives included testing the effective attenuation 
performance for use of a bubble curtain and investigation of SPLs 
produced during soft starts. Select results are reproduced here; the 
interested reader may find the entire reports posted at http://www.nmfs.noaa.gov/pr/permits/incidental.htm.

[[Page 43053]]



 
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                                                            Underwater           Airborne                    Distances to threshold (m)\7\
Pile size (in)      Hammer type \1\         n \2\    ---------------------------------------------------------------------------------------------------
                                                       RL\3\   SD\4\   TL\5\   RL\6\    SD       190       180       160       120       100       90
--------------------------------------------------------------------------------------------------------------------------------------------------------
24............  Impact.................        1 (2)     174     0.7    13.2      89     n/a      < 10      < 10       108       n/a        47       150
36............  Impact.................    10 (17)/9     182     5.7    16.4      92     2.3      < 10        28       398       n/a        48       150
48............  Impact.................        4 (8)     187     4.4    13.4      91     2.1   < 10/15        40     1,180       n/a        34       108
24............  Vibratory..............      4 (7)/2     164     5.0    17.4      91     1.4  ........  ........       n/a     2,635        14        45
36............  Vibratory (I)..........   23 (42)/30     162     4.3    15.1      93     2.9  ........  ........       n/a     6,082        20        64
36............  Vibratory (R)..........      21 (36)     157     4.5
48............  Vibratory (I)..........    7 (14)/11     163     5.1    16.3      94     3.2  ........  ........       n/a     5,046        24        75
48............  Vibratory (R)..........       8 (15)     155     4.5
12............  Vibratory (R)..........    \8\ 6 (4)     160     2.4    16.5  ......  ......  ........  ........       n/a     5,375        22        69
16............  Vibratory (I)..........       8 (16)     159     4.7          ......  ......  ........  ........       n/a
30............  Vibratory (I)..........      44 (87)     165     4.5          ......  ......  ........  ........       n/a                  44       138
--------------------------------------------------------------------------------------------------------------------------------------------------------
\1\ For vibratory hammer, I = installation and R = removal. Because of limited sample size for 24-in piles, all events were combined. All data for
  impact driving includes use of bubble curtain.
\2\ n = sample size, or number of measured pile driving events. For categories where two numbers are listed, sample size was different for underwater
  and airborne measurements. For underwater, each event may have up to two measurements because two hydrophones were deployed at different depths
  although both hydrophones did not produce usable data for all events. For airborne events, each event represents a single measurement. Information is
  presented as follows:  underwater events measured (total  measurements--maximum would be twice the total  events)/
  airborne events measured (if different).
\3\ Received level at 10 m, presented in dB re: 1 [micro]Pa rms.
\4\ Standard deviation
\5\ Transmission loss (log10). Mean TL calculations for vibratory driving were not separated by I/R. A single mean TL value was calculated for 12/16/30-
  in piles.
\6\ Received level at 15 m, presented in dB re: 20 [micro]Pa rms. Airborne measurements were combined for I/R events, as no difference in airborne SPLs
  would be expected. No near-source measurements were conducted for 12/16/30-in piles.
\7\ Indicated thresholds are in dB rms and correspond with those described previously under Description of Sound Sources and Distances to Thresholds.
  Combined values for mean distance to threshold were calculated for I/R events and for airborne sound. Values were calculated using interpolated TL
  values and SPL measurements at multiple distances from the source. A dash indicates that mean source level was below the relevant threshold. For
  impact driving of 48-in piles, mean distance to the 190 dB threshold was calculated as being < 10 m for measurements taken at the mid-depth hydrophone
  and 15 m for measurements taken at the deep hydrophone. For all others, mean of the mean values taken at mid-depth and deep hydrophone is presented.
\8\ These six events were measured in two episodes; i.e., three separate events were measured to provide a mean in each of two episodes.

Comparison of Predictions and Measurements

    The project activities involve vibratory removal of 12 to 16-in 
steel piles and removal by pneumatic chipping or similar method of 
concrete piles. Sound levels produced by the latter activity are not 
dependent upon pile size. As shown by the empirical data collected 
during 2011 activities, vibratory removal of 12- and 16-in piles would 
be expected to produce sound levels not exceeding the thresholds for 
Level A harassment (i.e., 180/190 dB rms). The actual distance to the 
120 dB rms behavioral harassment threshold is likely to be 
significantly smaller than predicted. There is no relevant comparison 
for pneumatic chipping.
    Mean distances to airborne thresholds were larger than those 
predicted for vibratory removal activities. The observed distances for 
2011 activities remain smaller than the least distance to an available 
haul-out area. However, regardless of actual distance to threshold, it 
is likely that any animal exposed to airborne sound that may result in 
behavioral harassment would also be exposed to underwater sound above 
behavioral harassment thresholds, even if hauled-out during pile 
removal activity. We recognize that swimming pinnipeds may be exposed 
to airborne sound that may cause behavioral harassment if they raise 
their heads above water within the relevant zone; however, for purposes 
of take estimation these are accounted for through estimation of 
incidental take resulting from underwater sound. An animal is 
considered to be `available' for incidental take by behavioral 
harassment only once per 24-hour period, regardless of source.

Comments and Responses

    We published a notice of receipt of the Navy's application and 
proposed IHA in the Federal Register on April 30, 2012 (77 FR 25408). 
During the 30-day comment period, NMFS received a letter from the 
Marine Mammal Commission (MMC). The MMC's comments, and our responses, 
are provided here. All measures proposed in the initial Federal 
Register notice are included within the authorization and NMFS has 
determined that they will effect the least practicable impact on the 
species or stocks and their habitats.
    Comment 1: The Commission recommends that we require the Navy to 
measure in-air sound levels as a function of distance from the 
pneumatic chipper and make concurrent observations of marine mammal 
behavioral responses to in-air sound produced by those activities.
    Response: We concur with the Commission's recommendation. As 
originally proposed, the Navy will measure airborne sound levels 
associated with removal of concrete piles. The specifics of the 
monitoring protocol are described in detail in the Navy's Acoustic 
Monitoring Plan. The Navy will make concurrent observations of 
behavioral reactions and, if possible, relate these to approximate 
received levels of sound in order to better understand what levels of 
sound might result in behavioral harassment given the context present 
at the time of the observation. The Commission also notes that they 
would welcome the opportunity to consult with us to (1) identify the 
types of activities that have the potential to take marine mammals by 
exposure to in-air sounds, (2) determine the best scientific basis for 
identifying exposure thresholds of concern, and (3) develop research 
strategies for gathering the information needed to set more reliable 
thresholds. We look forward to working with the Commission to better 
understand these issues.
    The Commission also encourages us to simply specify that the 
authorized number of takes of pinnipeds by Level B harassment, although 
based upon the predicted footprint of underwater sound, could occur by 
exposure to underwater and/or airborne sound when the animals are 
within an area that is ensonified to both 120 dB underwater (for non-
pulsed sounds, as will be produced by this project) and 90/100 dB in-
air (harbor seals and other pinnipeds, respectively), rather than 
attempting to predict these takes separately. We agree with that 
recommendation. Pinnipeds, whether hauled-out or looking with head 
above water in the project vicinity, may be exposed to both airborne 
and underwater sound levels that could cause behavioral reactions 
indicating harassment. We consider exposure of the same individual to 
different stimuli

[[Page 43054]]

that may potentially result in harassment--whether airborne or 
underwater sound or pulsed or non-pulsed sound--within the same 24-hour 
period to be a single incidence of take.
    Comment 2: The Commission recommends that we require the Navy to 
re-estimate the number of in-water and in-air takes using the overall 
density of harbor seals in Hood Canal (i.e., 3.74 animals/km\2\) or to 
use a different density estimate if monitoring data indicate one that 
is appropriate.
    Response: We disagree with the Commission's recommendation and feel 
that the density estimate used for estimating potential incidental take 
is sufficiently conservative. As described in greater detail in the FR 
notice of proposed authorization (77 FR 25408; April 30, 2012), the 
Navy's density estimate relies on work showing that, of an estimated 
1,088 seals resident to the Hood Canal, approximately 35 percent will 
be in the water at any given time (Huber et al., 2001; Jeffries et al., 
2003), producing a density estimate of 1.31 seals/km\2\. The Commission 
contends that this will result in an underestimate of take, because 
essentially all of the seals may enter the water over the matter of 
hours during which pile removal may occur in a day. It is possible that 
greater than 35 percent of seals could enter the water during the 
course of pile removal activity. However, remembering that the 
population estimate of 1,088 seals represents the entirety of Hood 
Canal (291 km\2\ vs. the 35.9 km\2\ predicted area of effect), it is 
unlikely that all of these animals would be exposed to elevated levels 
of sound from the project, even over the course of multiple days. 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. There are no existing data that would 
indicate that the proportion of individuals entering the water within 
the predicted area of effect during pile removal would be dramatically 
larger than 35 percent; thus, 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.
    In addition, there are a number of factors indicating that the 
density we used should not result in an underestimate of take. Hauled-
out harbor seals are necessarily at haul-outs, and 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 likely be exposed to 
underwater sound from the project; rather, only those animals embarking 
on foraging trips and entering the action area may be exposed. 
Moreover, because the Navy is unable to determine from field 
observations whether the same or different individuals are being 
exposed, each observation will be recorded as a new take, although an 
individual theoretically would only be considered as taken once in a 
given day.
    There are two final factors that support the conservatism of the 
1.31 density estimate: (1) limited surveys conducted during 
construction in Hood Canal during off days in 2011 produced an 
uncorrected density estimate of approximately 0.55 seals/km\2\; and (2) 
although authorized to incidentally take 1,668 seals (corrected for 
actual number of pile driving days) during two projects conducted in 
Hood Canal in 2011, the total estimate of actual take (observed takes 
and observations extrapolated to unobserved area) was only 187 seals.
    Comment 3: The Commission recommends that we require the Navy to 
implement soft-start procedures after 15 minutes if pile removal was 
delayed or shut down because of the presence of a marine mammal within 
or approaching the shutdown zone.
    Response: We disagree with this recommendation. The Commission 
cites several reasons why pinnipeds may remain in a shutdown zone after 
shutdown and yet be undetected by observers during the 15 minute 
clearance period (e.g., perception and availability bias). While this 
is possible in theory, we find it extremely unlikely that an animal 
could remain undetected in such a small zone and under typical 
conditions in Hood Canal. The shutdown zone for pinnipeds has a 10 m 
radial distance, while typical observation conditions in the Hood Canal 
are excellent. We believe the possibility of a pinniped remaining 
undetected in the shutdown zone, in relatively shallow water, for 
greater than 15 minutes is discountable. A requirement to implement 
soft start after every shutdown or delay less than 30 minutes in 
duration would be impracticable, resulting in significant construction 
delays and therefore extending the overall time required for the 
project, and thus the number of days on which disturbance of marine 
mammals could occur.
    Comment 4: The Commission recommends that we require the Navy to 
develop a monitoring strategy that ensures it will be able to detect 
and characterize marine mammal responses to the pile removal activities 
as a function of sound levels and distance from the pile removal sites.
    Response: We believe that the Navy, in consultation with us, has 
developed such a strategy. 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 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. 
The Commission notes that the Navy does not plan to use vessel-based 
observers in the far-field. This is technically correct for the EHW-1 
project, but there will be at least one vessel-based observer located 
on the far-field acoustic monitoring vessel associated with the 
concurrent EHW-2 project, for a minimum of 30 days. Information from 
this far-field observer effort will be applicable to both EHW-1 and 
EHW-2 projects, in terms of ensuring that actual marine mammal 
occurrence in the far-field is not substantially different from what 
has been assumed on the basis of 2011 monitoring, other past monitoring 
efforts specific to NBKB, and

[[Page 43055]]

information found in the literature. Additionally, 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 the more 
limited deep-water component of the EHW-2 monitoring plan, we can gain 
an acceptable understanding of marine mammal occurrence and behavior 
within the Level B harassment zone in deeper waters beyond the 
waterfront restricted area, which is intensively monitored. It is 
unclear what aspects of the monitoring goals or strategy the Commission 
considers inadequate.
    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 the Navy's 
concurrent EHW-2 construction project) impacting marine mammals in the 
Hood Canal area prior to issuing the incidental harassment 
authorization.
    Response: Section 101(a)(5)(D) of the MMPA requires NMFS to make a 
determination that the harassment incidental to a specified activity 
will have a negligible impact on the affected species or stocks of 
marine mammals, and will not result in an unmitigable adverse impact on 
the availability of marine mammals for taking for subsistence uses. 
Neither the MMPA nor NMFS' implementing regulations specify how to 
consider other activities and their impacts on the same populations. 
However, consistent with the 1989 preamble for NMFS' implementing 
regulations (54 FR 40338; September 29, 1989), the impacts from other 
past and ongoing anthropogenic activities are incorporated into the 
negligible impact analysis via their impacts on the environmental 
baseline (e.g., as reflected in the density/distribution and status of 
the species, population size and growth rate, and ambient noise).
    In addition, cumulative effects were addressed in the Navy's 
Environmental Assessment and in the biological opinion prepared for 
this action. 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 incidental harassment authorizations 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.
    Comment 7: The Commission recommends that we adopt a policy to 
provide an additional opportunity for public review and comment before 
amending authorizations if any substantive changes are made to them 
after they have been issued or if the information on which a negligible 
impact determination is based is significantly changed in a way that 
indicates the likelihood of an increased level of taking or impacts not 
originally considered.
    Response: We disagree with the Commission's contention that the 
referenced IHA modifications constituted a substantive change. The 
modifications involved small increases to the amount of incidental take 
of harbor porpoise authorized for two projects conducted in 2011 at 
NBKB in response to new information about harbor porpoise occurrence 
and habitat use at NBKB. In our findings for the referenced 
modification, we determined that authorization of the incidental 
taking, by Level B harassment only, of increased numbers of harbor 
porpoise did not alter the original scope of activity analyzed, the 
monitoring and mitigation measures implemented, or the impact analysis 
in a manner that materially affected the basis for our original 
findings. The increased level of authorized take for harbor porpoise 
remained a small number, by any definition of that term. The Inland 
Washington stock of harbor porpoise is not listed under the ESA, nor is 
it considered depleted or designated as a strategic stock under the 
MMPA. The increase in takings was considered negligible in comparison 
with the overall population of the stock. The modifications reflected a 
more complete understanding of harbor porpoise presence and use of 
habitat in the Hood Canal, but constituted a negligible increase in 
impacts to the stock. We believe that those modifications were within 
the scope of analysis supporting the determinations for the original 
IHAs, and that those original findings remained valid. Nevertheless, we 
thank the Commission for the recommendation and will consider it in the 
future for situations where substantive changes are required.

Description of Marine Mammals in the Area of the Specified Activity

    There are seven marine mammal species, four cetaceans and three 
pinnipeds, which may inhabit or transit through the waters nearby NBKB 
in the Hood Canal. These include the transient killer whale, harbor 
porpoise, Dall's porpoise, Steller sea lion, California sea lion, 
harbor seal, and humpback whale. 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, 
and therefore was excluded from further analysis. The Steller sea lion 
and humpback whale are the only marine mammals that may occur within 
the Hood Canal that are listed under the ESA; the humpback whale is 
listed as endangered and the eastern distinct population segment (DPS) 
of Steller sea lion is listed as threatened. All marine mammal species 
are protected under the MMPA. The FR notice (77 FR 25408; April 30, 
2012) summarizes the population status and abundance of these species 
and provides detailed life history information.

Potential Effects of the Specified Activity on Marine Mammals

    NMFS has determined that pile removal, as outlined in the project 
description, has the potential to result in behavioral harassment of 
marine mammals that may be swimming, foraging, or resting in the 
project vicinity while pile removal is being conducted. Pile removal 
could potentially harass those pinnipeds that are in the water close to 
the project site, whether their heads are above or below the surface. 
The FR notice (77 FR 25408; April 30, 2012) 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 proposed activities at NBKB would 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

[[Page 43056]]

project area. Therefore, the main impact issue associated with the 
proposed activity would 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 removal effects on likely marine mammal prey (i.e., fish) 
near NBKB and minor impacts to the immediate substrate during removal 
of piles during the wharf rehabilitation project. The FR notice (77 FR 
25408; April 30, 2012) describes these potential impacts in greater 
detail.

Previous Activity

    The proposed action for this IHA request represents the second year 
of a 2-year project. We issued an IHA for the first year of work on May 
24, 2011 (76 FR 30130). In accordance with the 2011 IHA, the Navy 
submitted a monitoring report, and the information contained therein 
was considered in this analysis. During the course of activities 
conducted under the previous authorization, the Navy did not exceed the 
take levels authorized under that IHA. Additional information regarding 
harbor porpoise, Steller sea lion, and humpback whale occurrence in the 
Hood Canal has been considered in this analysis.

Mitigation

    In order to issue an incidental take authorization (ITA) under 
section 101(a)(5)(D) of the MMPA, NMFS must, where applicable, set 
forth the permissible methods of taking pursuant to such activity, and 
other means of effecting the least practicable impact on such species 
or stock and its habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance, and on the 
availability of such species or stock for taking for certain 
subsistence uses (where relevant).
    The predicted results for zones of influence (ZOIs; see ``Estimated 
Take by Incidental Harassment'') were used to develop mitigation 
measures for pile removal activities at NBKB. ZOIs are often used to 
effectively represent the mitigation zone that would be established 
around each pile to prevent Level A harassment of marine mammals, and 
also establish zones within which Level B harassment of marine mammals 
may 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 removal 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 removal, if a 
marine mammal comes within 10 m (33 ft), 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, 
for example, movement of the barge to the pile location or removal of 
the pile from the water column/substrate via a crane (i.e., direct 
pull). For these activities, monitoring will take place from 15 minutes 
prior to initiation until the action is complete.

Monitoring and Shutdown

    The following measures apply to the Navy's mitigation through 
shutdown and disturbance zones:
    Shutdown Zone--For all pile removal activities, the Navy will 
establish a shutdown zone (defined as, at minimum, the area in which 
SPLs equal or exceed the 180/190 dB rms acoustic injury criteria). The 
purpose of a shutdown zone is to define an area within which shutdown 
of activity would occur upon sighting of a marine mammal (or in 
anticipation of an animal entering the defined area), thus preventing 
injury, serious injury, or death of marine mammals. Although 
predictions indicate (and empirical measurements confirm) that radial 
distances to the 180/190-dB threshold will be less than 10 m--or would 
not exist because source levels are lower than the threshold--shutdown 
zones will conservatively be set at a minimum 10 m. This precautionary 
measure is intended to further reduce any possibility of injury to 
marine mammals by incorporating a buffer to the 180/190-dB threshold 
within the shutdown area.
    Disturbance Zone--Disturbance zones are typically defined as the 
area in which SPLs equal or exceed 120 dB rms (for non-pulsed sound, as 
will be produced by the project activities). However, when the size of 
a disturbance zone is sufficiently large as to make monitoring of the 
entire area impracticable (as in the case of the vibratory removal zone 
here, predicted to encompass an area of 35.9 km\2\), the disturbance 
zone may be defined as some area that may reasonably be monitored or, 
alternatively, is a de facto zone defined by the distance that monitors 
are capable of observing from defined deployment locations. For removal 
of concrete piles, the Navy is able to monitor the entire area of 
predicted ensonification to levels exceeding the behavioral harassment 
criterion (542 m radial distance). However, for all activities, 
protected species observers (PSOs) will record all observations of 
marine mammals, whether estimated to be within a defined zone or not.
    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 PSOs 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). As with any such large action area, it is impossible to 
guarantee that all animals would be observed or to make comprehensive 
observations of fine-scale behavioral reactions to sound.
    All disturbance and shutdown zones would initially be based on the 
distances from the source that are predicted for each threshold level. 
However, should data from in-situ acoustic monitoring indicate that 
actual distances to these threshold zones are different, the size of 
the shutdown and disturbance zones would be adjusted accordingly. 
However, these adjustments should not be considered `real-time', as the 
collection and processing of a sufficient quantity of data upon which 
to base such a decision cannot generally occur on a real-time basis. 
Nevertheless, if data clearly indicate that zones are inaccurate and 
EHW-1 project activity is ongoing, appropriate adjustments of shutdown 
zones shall be made.
    Monitoring Protocols--Monitoring would be conducted for a minimum 
10 m shutdown zone surrounding each pile for the presence of marine 
mammals before, during, and after pile removal activities. In addition, 
PSOs shall record all observable incidences of marine mammal 
occurrence, regardless of distance from activity, and shall document 
any behavioral reactions. However, observations made outside the

[[Page 43057]]

shutdown zone will not result in shutdown; that pile segment would be 
completed without cessation, unless the animal approaches or enters the 
shutdown zone, at which point all pile removal activities would be 
halted.
    Detailed observations outside the Waterfront Restricted Area (WRA) 
as defined by the Port Security Barrier, are likely not possible, and 
it would be impossible for the Navy to account for all individuals 
occurring within the full disturbance zone with any degree of 
certainty. Monitoring would take place from 15 minutes prior to 
initiation through 30 minutes post-completion of pile removal 
activities. Pile removal activities include the time to remove a single 
pile or series of piles, as long as the time elapsed between uses of 
the pile removal equipment is no more than 30 minutes.
    The following additional measures would apply to visual monitoring:
    (a) Monitoring would be conducted by qualified observers. Qualified 
observers are trained biologists, with the following minimum 
qualifications:
     Visual acuity in both eyes (correction is permissible) 
sufficient for discernment of moving targets at the water's surface 
with ability to estimate target size and distance; use of binoculars 
may be necessary to correctly identify the target;
     Advanced education in biological science, wildlife 
management, mammalogy, or related fields (bachelor's degree or higher 
is required);
     Experience and ability to conduct field observations and 
collect data according to assigned protocols (this may include academic 
experience);
     Experience or training in the field identification of 
marine mammals, including the identification of behaviors;
     Sufficient training, orientation, or experience with the 
construction operation to provide for personal safety during 
observations;
     Writing skills sufficient to prepare a report of 
observations including but not limited to the number and species of 
marine mammals observed; dates and times when in-water construction 
activities were conducted; dates and times when in-water construction 
activities were suspended to avoid potential incidental injury from 
construction sound of marine mammals observed within a defined shutdown 
zone; and marine mammal behavior; and
     Ability to communicate orally, by radio or in person, with 
project personnel to provide real-time information on marine mammals 
observed in the area as necessary.
    A trained observer would be placed from the best vantage point(s) 
practicable, as defined in the Navy's Marine Mammal Monitoring Plan, to 
monitor for marine mammals and implement shutdown or delay procedures 
when applicable by calling for the shutdown to the equipment operator.
    (b) Prior to the start of pile removal activity, the shutdown zone 
will be monitored for 15 minutes to ensure that it is clear of marine 
mammals. Pile removal will only commence once observers have declared 
the shutdown zone clear of marine mammals; animals will be allowed to 
remain in the disturbance zone (i.e., must leave of their own volition) 
and their behavior will be monitored and documented.
    (c) If a marine mammal approaches or enters the shutdown zone 
during the course of pile removal operations, pile removal 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.

Acoustic Measurements

    Acoustic measurements would be used to empirically characterize 
source levels for pneumatic chipping. For further detail regarding the 
Navy's acoustic monitoring plan see ``Monitoring and Reporting''.

Timing Restrictions

    The Navy has set timing restrictions for pile removal activities to 
avoid in-water work when ESA-listed fish populations are most likely to 
be present. The in-water work window for avoiding negative impacts to 
fish species is July 16-February 15.

Soft-start

    The use of a soft-start procedure is believed to provide additional 
protection to marine mammals by warning, or providing marine mammals a 
chance to leave the area prior to the hammer operating at full 
capacity. The wharf rehabilitation project will utilize soft-start 
techniques for vibratory pile removal. The soft-start requires 
contractors 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.

Daylight Construction

    Pile removal and other in-water work will occur only during 
daylight hours (i.e., civil dawn to civil dusk).

Mitigation Effectiveness

    It should be recognized that although marine mammals will be 
protected through the use of measures described here, the efficacy of 
visual detection depends on several factors including the observer's 
ability to detect the animal, the environmental conditions (visibility 
and sea state), and monitoring platforms. All observers utilized for 
mitigation activities will be experienced biologists with training in 
marine mammal detection and behavior. Trained observers have specific 
knowledge of marine mammal physiology, behavior, and life history, 
which may improve their ability to detect individuals or help determine 
if observed animals are exhibiting behavioral reactions to construction 
activities.
    The Puget Sound region, including the Hood Canal, only infrequently 
experiences winds with velocities in excess of 25 kn (Morris et al., 
2008). The typically light winds afforded by the surrounding highlands 
coupled with the fetch-limited environment of the Hood Canal result in 
relatively calm wind and sea conditions throughout most of the year. 
The wharf rehabilitation project site has a maximum fetch of 8.4 mi 
(13.5 km) to the north, and 4.2 mi (6.8 km) to the south, resulting in 
maximum wave heights of from 2.85-5.1 ft (0.9-1.6 m) (Beaufort Sea 
State (BSS) between two and four), even in extreme conditions (30 kn 
winds) (CERC, 1984). Visual detection conditions are considered optimal 
in BSS conditions of three or less, which align with the conditions 
that should be expected for the wharf rehabilitation project at NBKB.
    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 proposed measures, as 
well as other measures considered, we have determined that the proposed 
mitigation

[[Page 43058]]

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 would 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.

Acoustic Monitoring

    The Navy will conduct acoustic monitoring for pneumatic chipping of 
concrete piles to characterize the actual source levels for this 
previously unstudied activity. Previous monitoring conducted by the 
Navy in 2011 provides data on site-specific propagation loss that may 
be applied to empirically measured source levels in order to determine 
actual distances to relevant thresholds. In addition, airborne acoustic 
monitoring will be conducted during pile removal through chipping.
    The Navy will conduct acoustic monitoring in accordance with the 
NMFS-approved acoustic monitoring plan. Please see that plan, available 
at http://www.nmfs.noaa.gov/pr/permits/incidental.htm, for more detail. 
At a minimum, acoustic monitoring, both underwater and in-air, will be 
conducted for five concrete piles. However, monitoring may be continued 
if necessary to collect a representative and usable dataset.

Visual Monitoring

    The Navy would 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 would be trained 
in marine mammal identification and behaviors. NMFS requires that the 
observers have no other construction-related tasks while conducting 
monitoring. The Navy will conduct biological monitoring in accordance 
with the NMFS-approved marine mammal monitoring plan. Please see that 
document, available at http://www.nmfs.noaa.gov/pr/permits/incidental.htm, for more information.
    Methods of Monitoring--The Navy would monitor the shutdown zone and 
surrounding waters before, during, and after pile removal. There would, 
at all times, be at least one observer stationed at an appropriate 
vantage point to observe the shutdown zones associated with each 
operating hammer. There would also at all times be at least one 
additional observer stationed to observe the surrounding waters within 
the WRA. Based on NMFS requirements, the Marine Mammal Monitoring Plan 
includes the following procedures for pile removal:
    (1) MMOs would be located at the best vantage point(s) in order to 
properly see the entire shutdown zone and as much of the disturbance 
zone as possible.
    (2) During all observation periods, observers will use binoculars 
and the naked eye to search continuously for marine mammals.
    (3) If the shutdown zone or surrounding waters within the WRA are 
obscured by fog or poor lighting conditions, pile removal at that 
location will not be initiated until that zone is visible.
    (4) The shutdown zone and surrounding waters within the WRA will be 
monitored for the presence of marine mammals before, during, and after 
any pile removal activity.
    Pre-activity Monitoring--The shutdown zone and surrounding waters 
within the WRA will be monitored for 15 minutes prior to initiating 
pile removal. If marine mammal(s) are present within the shutdown zone 
prior to pile removal, or during the soft start, the start of pile 
removal will be delayed until the animal(s) leave the shutdown zone. 
Pile removal will resume only after the PSO has determined, through 
observation or by waiting 15 minutes, that the animal(s) has moved 
outside the shutdown zone.
    During Activity Monitoring--The shutdown zone and surrounding 
waters within the WRA will also be monitored throughout the time 
required to remove a pile. If a marine mammal is observed entering the 
disturbance zone, a take will be recorded and behaviors documented. 
However, that pile segment will be completed without cessation, unless 
the animal enters or approaches the shutdown zone, at which point all 
pile removal activities will be halted. Pile removal can only resume 
once the animal has left the shutdown zone of its own volition or has 
not been re-sighted for a period of 15 minutes.
    Post-Activity Monitoring--Monitoring of the shutdown zone and 
surrounding waters within the WRA will continue for 30 minutes 
following the completion of pile removal.
    Individuals implementing the monitoring protocol will assess its 
effectiveness using an adaptive approach. Monitoring biologists will 
use their best professional judgment throughout implementation and will 
seek improvements to these methods when deemed appropriate. Any 
modifications to protocol will be coordinated between the Navy and 
NMFS.

Data Collection

    We require that the PSOs use NMFS-approved sighting forms. In 
addition to certain specific information related to mitigation 
implementation, as specified in the marine mammal monitoring plan, we 
require that, at a minimum, the following information be collected on 
the sighting forms:
    (1) Date and time that pile removal begins or ends;
    (2) Construction activities occurring during each observation 
period;
    (3) Weather parameters identified in the acoustic monitoring (e.g., 
percent cover, visibility);
    (4) Water conditions (e.g., sea state, tide state);
    (5) Species, numbers, and, if possible, sex and age class of marine 
mammals;
    (6) Marine mammal behavior patterns observed, including bearing and 
direction of travel, and if possible, the correlation to SPLs;
    (7) Distance from pile removal activities to marine mammals and 
distance from the marine mammals to the observation point;
    (8) Locations of all marine mammal observations; and
    (9) Other human activity in the area.

Reporting

    A draft acoustic monitoring report will be submitted within 90 
working days of the completion of the acoustic measurements. 
Separately, a draft marine mammal monitoring report would be submitted 
within 90 working days of the completion of construction activity. The 
report would include marine mammal observations pre-activity, during-
activity, and post-activity during pile removal days. Final reports 
would be prepared and submitted within 30 days following receipt of 
comments on the draft report. The Navy will provide estimates of the 
total incidental taking of marine mammals in the report. Among 
available data, the Navy will have GPS-corrected positions for both the 
observers and the individual piles being driven; estimated distances 
from the PSOs to observed marine mammals; and

[[Page 43059]]

actual pile-specific distances to relevant thresholds. Using this 
information, the Navy is able to determine which actual observations 
comprised incidental takes. The Navy will extrapolate these data to the 
remainder of unmonitored area ensonified to levels equaling or 
exceeding relevant thresholds for acoustic disturbance to reach a total 
estimate of the actual incidental taking.
    Contents of the reports will be in accordance with the respective 
monitoring plans and, at minimum, will include:
     Date and time of activity;
     Water and weather conditions (e.g., sea state, tide state, 
percent cover, visibility);
     Description of the pile removal activity (e.g., size and 
type of piles, machinery used);
     The vibratory hammer force or chipping hammer setting used 
to extract the piles;
     A description of the monitoring equipment;
     The distance between hydrophone(s) and pile;
     The depth of the hydrophone(s);
     The physical characteristics of the bottom substrate from 
which the pile was extracted (if possible);
     The rms range and mean for each monitored pile;
     The results of the acoustic measurements, including the 
frequency spectrum, peak and rms SPLs for each monitored pile;
     The results of the airborne sound measurements (unweighted 
levels);
     Date and time observation is initiated and terminated;
     A description of any observable marine mammal behavior in 
the immediate area and, if possible, the correlation to underwater 
sound levels occurring at that time;
     Actions performed to minimize impacts to marine mammals;
     Times when pile removal is stopped due to presence of 
marine mammals within shutdown zones and time when pile removal 
resumes;
     Results, including the detectability of marine mammals, 
species and numbers observed, sighting rates and distances, behavioral 
reactions within and outside of shut down zones; and
     A refined take estimate based on the number of marine 
mammals observed in the shutdown and disturbance zones.

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 remote. 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 an underwater sound 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 10 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 would not.
    The project area is not believed to be particularly important 
habitat for 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 the proposed activities are expected to affect 
only a relatively small number of individual marine mammals, although 
those effects could be recurring if the same individuals remain in the 
project vicinity.
    The Navy requested authorization for the potential taking of small 
numbers of Steller sea lions, California sea lions, harbor seals, 
transient killer whales, Dall's porpoises, and harbor porpoises in the 
Hood Canal that may result from pile removal during construction 
activities associated with the wharf rehabilitation project described 
previously in this document. The potential for incidental take of 
humpback whale is considered discountable; however, should a humpback 
whale occur within the project area the activity would have to cease in 
order to avoid an unauthorized take. The takes requested are expected 
to have no more than a minor effect on individual animals and no effect 
at the population level for these species. Any effects experienced by 
individual marine mammals are anticipated to be limited to short-term 
disturbance of normal behavior or temporary displacement of animals 
near the source of the sound.

Marine Mammal Densities

    For all species, the best scientific information available was used 
to construct density estimates or estimate local abundance. Of 
available information deemed suitable for use, the data that produced 
the most conservative (i.e., highest) density or abundance estimate for 
each species was used. For harbor seals, this involved published 
literature describing harbor seal research conducted in Washington and 
Oregon as well as more specific counts conducted in Hood Canal (Huber 
et al., 2001; Jeffries et al., 2003). Killer whales are known from two 
periods of occurrence (2003 and 2005) and are not known to 
preferentially use any specific portion of the Hood Canal. Therefore, 
density was calculated as the maximum number of individuals present at 
a given time during those occurrences (London, 2006), divided by the 
area of Hood Canal. The best information available for the remaining 
species in Hood Canal came from surveys conducted by the Navy at the 
NBKB waterfront or in the vicinity of the project area. These consist 
of three discrete sets of survey effort, which were described in detail 
in the FR notice. Please see that document for an in-depth discussion 
(77 FR 25408; April 30, 2012).
    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

[[Page 43060]]

distributed in the project area. However, it should be noted that there 
have been no observations of cetaceans within the WRA security barrier; 
the barrier thus appears to effectively prevent cetaceans from 
approaching the shutdown zones (please see Figure 6-2 of the Navy's 
application; the WRA security barrier, which is not denoted in the 
figure legend, is represented by a thin gray line). Although source 
levels associated with the proposed actions are so low that no Level A 
harassments would likely occur even in the absence of any mitigation 
measures, it appears that cetaceans at least are not at risk of Level A 
harassment at NBKB even from louder activities (e.g., impact pile 
driving). The remaining species that occur in the project area, Steller 
sea lion and California sea lion, do not appear to utilize most of Hood 
Canal. The sea lions appear to be attracted to the man-made haul-out 
opportunities along the NBKB waterfront while dispersing for foraging 
opportunities elsewhere in Hood Canal. California sea lions were not 
reported during aerial surveys of Hood Canal (Jeffries et al., 2000), 
and Steller sea lions have only been documented at the NBKB waterfront.

Description of Take Calculation

    The take calculations presented here rely on the best data 
currently available for marine mammal populations in the Hood Canal. 
The methodology for estimating take was described in detail in the FR 
notice (77 FR 25408; April 30, 2012). The ZOI impact area is the 
estimated range of impact to the sound criteria. The distances 
specified in Table 1 were used to calculate ZOI around each pile; 
although attenuation due to landforms was considered when defining the 
ZOI, as described in the text following Table 1. The ZOI impact area 
took into consideration the possible affected area of the Hood Canal 
from the pile removal 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. Although mean distances 
to thresholds as determined during acoustic monitoring in 2011 may 
differ somewhat--primarily in that the distances to the 120 dB 
threshold are likely to be much smaller for vibratory removal--we have 
maintained the take estimated based on predicted distances, as analyzed 
in the notice of proposed authorization. Therefore, these take 
estimates are likely to be conservative.
    For sea lions, the surveys offering the most conservative estimates 
of abundance do not have a defined survey area and so are not suitable 
for deriving a density construct. Instead, abundance is estimated on 
the basis of previously described opportunistic sighting information at 
the NBKB waterfront, and it is assumed that the total amount of animals 
known from NBKB haul-outs would be `available' to be taken in a given 
pile removal day. Thus, for these two species, take is estimated by 
multiplying abundance by days of activity. The total number of days 
spent removing piles is expected to be a maximum of 15 for vibratory 
removal and 32 for chipping.
    The exposure assessment methodology is an estimate of the numbers 
of individuals exposed to the effects of pile removal activities 
exceeding NMFS-established thresholds. Of note in these exposure 
estimates, mitigation methods (i.e., visual monitoring and the use of 
shutdown zones) were not quantified within the assessment and 
successful implementation of this mitigation is not reflected in 
exposure estimates. Results from acoustic impact exposure assessments 
should be regarded as conservative estimates.
    Airborne Sound--No incidents of incidental take resulting solely 
from airborne sound are likely, as even the larger distances to the 
harassment thresholds seen in acoustic monitoring from 2011 would not 
reach any areas where pinnipeds may haul out. While pinnipeds swimming 
within these zones may be exposed to airborne sound of sufficient 
intensity to result in behavioral harassment, these animals would 
previously have been `taken' as a result of exposure to underwater 
sound above the behavioral harassment thresholds, which are in all 
cases larger than those associated with airborne sound. Thus, the 
behavioral harassment of these animals is already accounted for in 
these estimates of potential take. Multiple incidents of exposure to 
sound above NMFS' thresholds for behavioral harassment are not believed 
to result in increased behavioral disturbance, in either nature or 
intensity of disturbance reaction.
    The derivation of density or abundance estimates for each species, 
as well as further description of the rationale for each take estimate, 
was described in detail in the FR notice (77 FR 25408; April 30, 2012). 
Total take estimates, and numbers of take per species to be authorized, 
are presented in Table 4. It is worth noting that the Navy will attempt 
to conclude project activities as early as possible after the beginning 
of the in-water work window. With an estimated 47 days of project 
activities, it is possible that project activities could conclude 
before the sea lion species begin to arrive in significant numbers; 
thus, the estimates for sea lions may be very conservative.

California Sea Lion

    California sea lions are present in Hood Canal during much of the 
year with the exception of mid-June through August. California sea 
lions occur regularly in the vicinity of the project site from 
September through mid-June. 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 have rarely been reported, either hauled out or 
swimming, elsewhere in Hood Canal (Jeffries, 2007). Female California 
sea lions are rarely observed north of the California/Oregon border; 
therefore, only adult and sub-adult males are expected to be exposed to 
project impacts.
    The ZOI for vibratory removal encompasses areas where California 
sea lions are known to haul-out; assuming that 26 individuals could be 
taken per day of vibratory removal provides an estimate of 390 takes 
for that activity. The ZOI for pneumatic chipping does not encompass 
areas where California sea lions are known to occur; nevertheless, it 
is likely that some individuals would transit this area in route to 
haul out or forage. Therefore, although it is possible that no 
California sea lions would be exposed to sound from pneumatic chipping, 
we expect that at least one individual California sea lion could be 
exposed to sound levels indicating Level B harassment per day of 
pneumatic chipping.

Steller Sea Lion

    Steller sea lions were first documented at the NBKB waterfront in 
November 2008, while hauled out on submarines at Delta Pier 
(Bhuthimethee, 2008; Navy, 2010) and have been periodically observed 
since that time. Steller sea lions typically occur at NBKB from 
November through April; however, the first October sightings of Steller 
sea lions at NBKB occurred in 2011. Based on waterfront observations, 
Steller sea lions appear to use available haul-outs (typically in the 
vicinity of Delta Pier, approximately one mile south of the project 
area) and habitat similarly to California sea lions, although in lesser

[[Page 43061]]

numbers. On occasions when Steller sea lions are observed, they 
typically occur in mixed groups with California sea lions also present, 
allowing observers to confirm their identifications based on 
discrepancies in size and other physical characteristics.
    The time period from November through April coincides with the time 
when Steller sea lions are frequently observed in Puget Sound. Only 
adult and sub-adult males are likely to be present in the project area 
during this time; female Steller sea lions have not been observed in 
the project area. Since there are no known breeding rookeries in the 
vicinity of the project site, Steller sea lion pups are not expected to 
be present. By May, most Steller sea lions have left inland waters and 
returned to their rookeries to mate. Although sub-adult individuals 
(immature or pre-breeding animals) will occasionally remain in Puget 
Sound over the summer, observational data have indicated that Steller 
sea lions are present only from October through April and not during 
the summer months.
    Steller sea lions are known only from haul-outs over one mile from 
the project area. The ZOI for vibratory removal encompasses areas where 
Steller sea lions are known to haul-out; assuming that one individual 
could be taken per day of vibratory removal provides an estimate of 
fifteen takes for that activity. However, the available abundance 
information does not reflect the nature of Steller sea lion occurrence 
at NBKB. According to the most recent observational information, if 
Steller sea lions are present at NBKB, it is possible that as many as 
four individuals could be present on submarines docked at Delta Pier or 
in waters adjacent to these haul-outs. Thus, we conservatively assume 
that up to four individuals could be exposed to sound levels indicating 
Level B harassment per day of vibratory pile removal. Similar to 
California sea lions, the ZOI for pneumatic chipping does not encompass 
areas where Steller sea lions are known to occur; nevertheless, it is 
possible that some individuals could transit this area in route to haul 
out or forage. Therefore, although it is possible that no Steller sea 
lions would be exposed to sound from pneumatic chipping, we expect that 
the equivalent of at least one individual Steller sea lion could be 
exposed to sound levels indicating Level B harassment per day of 
pneumatic chipping.

Harbor Seal

    Harbor seals are the most abundant marine mammal in Hood Canal, and 
they can occur anywhere in Hood Canal waters year-round. During most of 
the year, all age and sex classes could occur in the project area 
throughout the period of construction activity. As there are no known 
regular pupping sites in the vicinity of the project area, harbor seal 
neonates are not expected to be present during pile removal. Otherwise, 
during most of the year, all age and sex classes could occur in the 
project area throughout the period of construction activity. Harbor 
seal numbers increase from January through April and then decrease from 
May through August as the harbor seals move to adjacent bays on the 
outer coast of Washington for the pupping season. The main haul-out 
locations for harbor seals in Hood Canal are located on river delta and 
tidal exposed areas at various river mouths, with the closest haul-out 
area to the project area being 10 mi (16 km) southwest of NBKB (London, 
2006). Please see Figure 4-1 of the Navy's application for a map of 
haul-out locations in relation to the project area.

Humpback Whales

    One humpback whale has recently been documented in Hood Canal. This 
individual was originally sighted on January 27, 2012, and was last 
reported on February 23, 2012, indicating that the animal has almost 
certainly left the area. Although known to be historically abundant in 
the inland waters of Washington, no other confirmed documentation of 
humpback whales in Hood Canal is available. Their presence has likely 
not occurred in several decades, with the last known reports being 
anecdotal accounts of three humpback sightings from 1972-82. Although a 
calculated density (representing this single known individual in Hood 
Canal) is presented in Table 4, the important point is that we consider 
it extremely unlikely that any humpback whales would be present during 
the project timeframe. Therefore, the likelihood of incidental take of 
humpback whales is discountable.

Killer Whales

    Transient killer whales are uncommon visitors to Hood Canal. 
Transients may be present in the Hood Canal anytime during the year and 
traverse as far as the project site. Resident killer whales have not 
been observed in Hood Canal, but 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. Subsequent aerial surveys suggest 
that there has not been a sharp decline in the local seal population 
from these sustained feeding events (London, 2006).

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.

Harbor Porpoise

    Harbor porpoises may be present in the Hood Canal year-round; their 
presence had previously been considered rare. During waterfront surveys 
of NBKB nearshore waters from 2008-10 only one harbor porpoise had been 
observed. However, during monitoring of Navy actions in 2011, several 
sightings indicated that their presence may be more frequent in deeper 
waters of Hood Canal than had been believed on the basis of existing 
survey data and anecdotal evidence. Subsequently, the Navy conducted 
dedicated vessel-based line transect surveys on days when no 
construction activity occurred (due to security, weather, etc.) and 
made regular observations of harbor porpoise groups. It should be noted 
that, due to the availability of corrected trackline distances for 
harbor porpoise surveys conducted in 2011, that density estimate has 
been revised from 0.250 animals/km\2\ to 0.231 animals/km\2\ for survey 
data through September 28, 2011.
    Potential takes could occur if individuals of these species move 
through the area on foraging trips when pile removal is occurring. 
Individuals that are taken could exhibit behavioral changes such as 
increased swimming speeds, increased surfacing time, or decreased 
foraging. Most likely, individuals may move away from the sound source 
and be temporarily displaced from the areas of pile removal. Potential 
takes by disturbance would likely have a negligible short-term effect 
on individuals and not result in population-level impacts.

[[Page 43062]]



                         Table 8--Number of Potential Incidental Takes of Marine Mammals Within Various Acoustic Threshold Zones
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                                         Underwater                          Airborne
                                                                   ----------------------------------------------------------------------
                                                                                      Disturbance                                         Total proposed
                      Species                          Density/                       threshold--        Disturbance                        authorized
                                                       Abundance        Injury         vibratory    threshold--pneumatic    Disturbance        takes
                                                                     threshold \1\   removal  (120   chipping  (120 dB)    threshold \2\
                                                                                          dB)
--------------------------------------------------------------------------------------------------------------------------------------------------------
California sea lion...............................        \3\ 26.2               0           * 390               * 32                  0             422
Steller sea lion..................................         \3\ 1.2               0            * 60               * 32                  0              92
Harbor seal.......................................            1.31               0             705                 32                  0             737
Humpback whale....................................           0.003               0               0                  0                N/A               0
Killer whale......................................           0.038               0              15                  0                N/A              15
Dall's porpoise...................................           0.014               0              15                  0                N/A              15
Harbor porpoise...................................           0.231               0             120                  0                N/A             120
                                                   -----------------------------------------------------------------------------------------------------
    Total.........................................               0           1,305              96                  0              1,401
--------------------------------------------------------------------------------------------------------------------------------------------------------
* See preceding species-specific discussions for description of take estimate.
\1\ Acoustic injury threshold is 190 dB for pinnipeds and 180 dB for cetaceans. No activity would produce source levels equal to 190 dB, while only
  vibratory removal would produce a source level of 180 dB.
\2\ Acoustic disturbance threshold is 100 dB for sea lions and 90 dB for harbor seals. We believe that any animal subject to levels of airborne sound
  that may result in harassment--whether hauled-out or in the water--would likely also be exposed to underwater sound above behavioral harassment
  thresholds within the same day. Therefore, no take authorization specific to airborne sound is warranted.
\3\ Figures presented are abundance numbers, not density, and are calculated as the average of average daily maximum numbers per month. Abundance
  numbers are rounded to the nearest whole number for take estimation.

Negligible Impact and Small Numbers Analysis and Preliminary 
Determination

    NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ``* * 
*an impact resulting from the specified activity that cannot be 
reasonably expected to, and is not reasonably likely to, adversely 
affect the species or stock through effects on annual rates of 
recruitment or survival.'' In making a negligible impact determination, 
we consider 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.
    Pile removal activities associated with the wharf rehabilitation 
project, as outlined previously, have the potential to disturb or 
displace marine mammals. Specifically, the project activities may 
result in take, in the form of Level B harassment (behavioral 
disturbance) only, from underwater sounds generated through pile 
removal. No mortality, serious injury, or Level A harassment is 
anticipated given the nature of the activity (i.e., non-pulsed sound 
with low source levels) and measures designed to minimize the 
possibility of injury to marine mammals, while Level B harassment would 
be reduced to the level of least practicable adverse impact for the 
same reasons. Specifically, these removal methods would produce lower 
source levels than would pile installation with a vibratory hammer, 
which does not have significant potential to cause injury to marine 
mammals due to its sound source characteristics and relatively low 
source levels. Pile removal will either not start or be halted if 
marine mammals approach the shutdown zone (described previously in this 
document). The pile removal activities analyzed here carry 
significantly less risk of impact to marine mammals than did other 
construction activities analyzed and monitored within the Hood Canal, 
including two recent projects conducted by the Navy at the same 
location (test pile project and the first year of EHW-1 pile 
replacement work) as well as work conducted in 2005 for the Hood Canal 
Bridge (SR-104) by the Washington Department of Transportation. These 
activities have taken place with no reported injuries or mortality to 
marine mammals.
    The numbers of authorized take for marine mammals would be 
considered small relative to the relevant stocks or populations even if 
each estimated taking occurred to a new individual--an extremely 
unlikely scenario. The proposed numbers of authorized take represent 5 
percent of the relevant stock for harbor seals, 4.2 percent for 
transient killer whales, and 1.1 percent for harbor porpoises; the 
proposed numbers are less than 1 percent for the remaining species. 
However, even these low numbers represent potential instances of take, 
not the number of individuals taken. That is, it is likely that a 
relatively small subset of Hood Canal harbor seals, which is itself a 
small subset of the regional stock, would be harassed by project 
activities.
    For example, while the available information and formula estimate 
that as many as 737 exposures of harbor seals to stimuli constituting 
Level B harassment could occur, that number represents some portion of 
the approximately 1,088 harbor seals resident in Hood Canal 
(approximately 7 percent of the regional stock) that could potentially 
be exposed to sound produced by pile removal activities on multiple 
days during the project. 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. Repeated exposures of individuals to 
levels of sound that may cause Level B harassment are unlikely to 
result in hearing impairment or to significantly disrupt foraging 
behavior. Thus, even repeated Level B harassment of some small subset 
of the overall stock is unlikely to result in any significant realized 
decrease in viability for Hood Canal harbor seals, and thus would not 
result in any adverse impact to the stock as a whole.
    NMFS has determined that the impact of the previously described 
wharf rehabilitation project may result, at worst, in a temporary 
modification in behavior (Level B harassment) of small numbers of 
marine mammals. No injury, serious injury, or mortality is anticipated 
as a result of the specified activity, and none will be authorized. 
Additionally, animals in the area are not expected to incur hearing 
impairment (i.e., TTS or PTS) or non-auditory

[[Page 43063]]

physiological effects. For pinnipeds, the absence of any major 
rookeries and only a few isolated and opportunistic haul-out areas near 
or adjacent to the project site means that potential takes by 
disturbance would have an insignificant short-term effect on 
individuals and would not result in population-level impacts. 
Similarly, for cetacean species the absence of any known regular 
occurrence adjacent to the project site means that potential takes by 
disturbance would have an insignificant short-term effect on 
individuals and would not result in population-level impacts. Due to 
the nature, degree, and context of behavioral harassment anticipated, 
the activity is not expected to impact rates of recruitment or 
survival.
    While the number of marine mammals potentially incidentally 
harassed would depend on the distribution and abundance of marine 
mammals in the vicinity of the survey activity, the number of potential 
harassment takings is estimated to be small relative to regional stock 
or population number, and has been mitigated to the lowest level 
practicable through incorporation of the mitigation and monitoring 
measures mentioned previously in this document. This activity is 
expected to result in a negligible impact on the affected species or 
stocks.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the mitigation and monitoring 
measures, NMFS finds that the proposed wharf construction project would 
result in the incidental take of small numbers of marine mammals, by 
Level B harassment only, and that the total taking from the activity 
would 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 would 
not affect any subsistence activity. Further, no population or stock 
level impacts to marine mammals are anticipated or authorized. As a 
result, no impacts to the availability of the species or stock to the 
Pacific Northwest treaty tribes are expected as a result of the 
activities. Therefore, no relevant subsistence uses of marine mammals 
are implicated by this action.

Endangered Species Act (ESA)

    There are two ESA-listed marine mammal species with known 
occurrence in the project area: The eastern DPS of the Steller sea 
lion, listed as threatened, and the humpback whale, listed as 
endangered. Because of the potential presence of these species, the 
Navy requested a formal consultation with the NMFS Northwest Regional 
Office under section 7 of the ESA. NMFS' Office of Protected Resources 
also initiated formal consultation on its authorization of incidental 
take of Steller sea lions. These consultations are complete, with the 
determination that these activities are not likely to jeopardize the 
continued existence of the threatened Steller sea lion and are not 
likely to adversely affect humpback whales. These species do not have 
critical habitat in the action area.

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), and 
NOAA Administrative Order 216-6, the Navy prepared an Environmental 
Assessment (EA) to consider the direct, indirect and cumulative effects 
to the human environment resulting from the pile replacement project. 
We adopted that EA in order to assess the impacts to the human 
environment of issuance of an IHA to the Navy and signed a Finding of 
No Significant Impact (FONSI) on May 17, 2011. On the basis of new 
information related to the occurrence of marine mammals in the Hood 
Canal, the Navy prepared a supplement to that EA. We have adopted that 
supplemental EA and signed a new FONSI on July 11, 2012.

Determinations

    We have determined that the impact of conducting the specific 
activities described in this notice and in the IHA request in the 
specific geographic region in Hood Canal, Washington may result, at 
worst, in a temporary modification in behavior (Level B harassment) of 
small numbers of marine mammals. Further, this activity is expected to 
result in a negligible impact on the affected species or stocks of 
marine mammals. The provision requiring that the activity not have an 
unmitigable impact on the availability of the affected species or stock 
of marine mammals for subsistence uses is not implicated for this 
action.

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, 2012, through February 15, 2013, provided the 
previously described mitigation, monitoring, and reporting requirements 
are incorporated.

    Dated: July 13, 2012.
Helen M. Golde,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. 2012-17638 Filed 7-20-12; 8:45 am]
BILLING CODE 3510-22-P