Takes of Marine Mammals Incidental to Specified Activities; Taking Marine Mammals Incidental to a Geohazard Survey in the Beaufort Sea, Alaska, 21521-21550 [2014-08534]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 79, Number 73 (Wednesday, April 16, 2014)]
[Notices]
[Pages 21521-21550]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2014-08534]



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Vol. 79

Wednesday,

No. 73

April 16, 2014

Part II





Department of Commerce





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National Oceanic and Atmospheric Administration





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Takes of Marine Mammals Incidental to Specified Activities; Taking 
Marine Mammals Incidental to a Geohazard Survey in the Beaufort Sea, 
Alaska; Notice

Federal Register / Vol. 79, No. 73 / Wednesday, April 16, 2014 / 
Notices

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD229


Takes of Marine Mammals Incidental to Specified Activities; 
Taking Marine Mammals Incidental to a Geohazard Survey in the Beaufort 
Sea, Alaska

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

ACTION: Notice; proposed incidental harassment authorization; request 
for comments.

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SUMMARY: NMFS has received an application from BP Exploration (Alaska) 
Inc. (BP) for an Incidental Harassment Authorization (IHA) to take 
marine mammals, by harassment, incidental to conducting a shallow 
geohazard survey in Foggy Island Bay, Beaufort Sea, Alaska, during the 
2014 open water season. Pursuant to the Marine Mammal Protection Act 
(MMPA), NMFS is requesting comments on its proposal to issue an IHA to 
BP to incidentally take, by Level B harassment only, marine mammals 
during the specified activity.

DATES: Comments and information must be received no later than May 16, 
2014.

ADDRESSES: Comments on the application should be addressed to Jolie 
Harrison, Supervisor, Incidental Take Program, Permits and Conservation 
Division, Office of Protected Resources, National Marine Fisheries 
Service, 1315 East-West Highway, Silver Spring, MD 20910. The mailbox 
address for providing email comments is ITP.Nachman@noaa.gov. NMFS is 
not responsible for email comments sent to addresses other than the one 
provided here. Comments sent via email, including all attachments, must 
not exceed a 25-megabyte file size.
    Instructions: All comments received are a part of the public record 
and will generally be posted to https://www.nmfs.noaa.gov/pr/permits/incidental.htm without change. All Personal Identifying Information 
(e.g., name, address) voluntarily submitted by the commenter may be 
publicly accessible. Do not submit Confidential Business Information or 
otherwise sensitive or protected information.
    An electronic copy of the application containing a list of the 
references used in this document may be obtained by writing to the 
address specified above, telephoning the contact listed below (see FOR 
FURTHER INFORMATION CONTACT), or visiting the internet at: https://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited in this 
notice may also be viewed, by appointment, during regular business 
hours, at the aforementioned address.

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

SUPPLEMENTARY INFORMATION:

Background

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

Summary of Request

    On February 4, 2014, NMFS received an application from BP for the 
taking of marine mammals incidental to conducting a shallow geohazard 
survey. NMFS determined that the application was adequate and complete 
on March 6, 2014.
    BP proposes to conduct a shallow geohazard survey in Federal and 
state waters of Foggy Island Bay in the Beaufort Sea during the open-
water season of 2014. The proposed activity would occur between July 1 
and September 30; however, airgun and other sound source equipment 
operations would cease on August 25. The following specific aspects of 
the proposed activity are likely to result in the take of marine 
mammals: airguns and scientific sonars/devices. Take, by Level B 
harassment only, of 9 marine mammal species is anticipated to result 
from the specified activity.

Description of the Specified Activity

Overview

    BP's proposed shallow geohazard survey would consist of two phases: 
a site survey and a sonar survey. During the first phase, the Site 
Survey, the emphasis is on obtaining shallow geohazard data using an 
airgun array and a towed streamer. During the second phase, the Sonar 
Survey, data will be acquired both in the Site Survey location and 
subsea pipeline corridor area (see Figure 1 in BP's application) using 
the multibeam echosounder, sidescan sonar, subbottom profiler, and the 
magnetometer. The total discharge volume of the airgun array will not 
exceed 30 cubic inches (in\3\). The program is proposed to be conducted 
during the 2014 open-water season.
    The purpose of the proposed shallow geohazard survey is to evaluate 
development of the Liberty field. The Liberty reservoir is located in 
federal waters in Foggy Island Bay about 8 miles (mi) east of the 
Endicott Satellite Drilling Island. The project's preferred alternative 
is to build a gravel island situated over the reservoir. In support of 
the preferred alternative, a Site Survey is planned with an emphasis on 
obtaining two-dimensional high-resolution (2DHR) shallow geohazard data 
using an airgun array and a towed streamer. Additional infrastructure 
required for the preferred alternative would include a subsea pipeline. 
A Sonar Survey, using multibeam echosounder, sidescan sonar, subbottom 
profiler, and magnetometer is proposed over the Site Survey location 
and subsea pipeline corridor area. The purpose of this proposed survey 
is to evaluate the existence and location of archaeological resources 
and potential geologic hazards on the seafloor and in the shallow 
subsurface.

Dates and Duration

    The planned start date is approximately July 1, 2014, with data

[[Page 21523]]

acquisition beginning when open water conditions allow. The survey is 
expected to take approximately 20 days to complete, not including 
weather downtime. Each phase of the survey (i.e., site survey and sonar 
survey) has an expected duration of 7.5 days based on a 24-hour 
workday. Between the first and second phase, the operations will be 
focused on changing equipment for about 5 days (i.e., no active sound 
sources would be used to acquire data during this time). To limit 
potential impacts to the bowhead whale fall migration and subsistence 
hunting, airgun and sonar operations will cease by midnight on August 
25. Demobilization of equipment would continue after airgun and sonar 
operations end but would be completed by September 30. Therefore, the 
proposed dates for the IHA (if issued) are July 1 through September 30, 
2014.

Specified Geographic Region

    The proposed shallow geohazards survey would occur in Federal and 
state waters of Foggy Island Bay in the Beaufort Sea, Alaska. The 
project area lies mainly within the Liberty Unit but also includes 
portions of the Duck Island Unit, as well as non-unit areas. Figure 1 
in BP's application outlines the proposed survey acquisition areas, 
including proposed boundaries for the two phases of the project. The 
Phase 1 Site Survey, focused on obtaining shallow geohazard data using 
an airgun array and towed streamer, will occur within approximately 12 
mi\2\. The Phase 2 Sonar Survey will occur over the Site Survey area 
and over approximately 5 mi\2\ within the 29 mi\2\ area identified in 
Figure 1 of BP's application. Water depth in this area ranges from 
about 2-24 ft. Activity outside the area delineated in Figure 1 of BP's 
application may include vessel turning while using airguns, vessel 
transit, and other vessel movements for project support and logistics. 
The approximate boundaries of the two survey areas are between 
70[deg]14'10'' N. and 70[deg]20'20'' N. and between 147[deg]29'05'' W. 
and 148[deg]52'30'' W.

Detailed Description of Activities

    The activities associated with the proposed shallow geohazard 
survey include vessel mobilization, navigation and data management, 
housing and logistics, and data acquisition.
1. Vessel Mobilization
    One vessel will be used for the geohazard survey. The proposed 
survey vessel (R/V Thunder or equivalent) is about 70 x 20 ft in size. 
This vessel will be transported to the North Slope by truck and 
prepared and launched at West Dock or Endicott. Vessel preparation 
includes the assembly of navigation, acoustic, and safety equipment. 
Initial fueling and stocking of recording equipment will also be part 
of the vessel preparations. Once assembled, the navigation and acoustic 
systems will be tested at West Dock or at the project site.
2. Navigation and Data Management
    The vessel will be equipped with Differential Global Navigation 
Satellite System receivers capable of observing dual constellations and 
backup. Corrected positions will be provided via a precise point 
positioning solution. A kinematic base station will be kept at the 
housing facilities in Deadhorse to mitigate against the inability to 
acquire a precise point positioning signal. Tidal corrections will be 
determined through Global Navigation Satellite System computation, 
comparison with any local tide gauges, and, if available, with tide 
gauges operated by other projects.
    A navigation software package will display known obstructions, 
islands, and identified areas of sensitivity. The software will also 
show the pre-determined source line positions within the two survey 
areas. The information will be updated as necessary to ensure required 
data coverage. The navigation software will also record all measured 
equipment offsets and corrections and vessel and equipment position at 
a frequency of no less than once per 5 seconds for the duration of the 
project.
3. Housing and Logistics
    Approximately 20 people will be involved in the operation. Most of 
the crew will be accommodated at existing camps, and some crew will be 
housed on the vessel. Support activities, such as crew transfers and 
vessel re-supply are primarily planned to occur at Endicott and West 
Dock. However, support activities may also occur at other nearby vessel 
accessible locations if needed (e.g., East Dock). Equipment staging and 
onshore support will primarily occur at West Dock but may also take 
place at other existing road-accessible pads within the Prudhoe Bay 
Unit area as necessary. For protection from weather, the vessel may 
anchor near West Dock, near the barrier islands, or other near shore 
locations.
4. Data Acquisition
    Equipment proposed for use during the proposed shallow geohazard 
survey includes airgun, multibeam echosounder, sidescan sonar, 
subbottom profiler, and a marine magnetometer. Details related to data 
acquisition are summarized next.
    Survey Design: One vessel will be used for the proposed survey. The 
proposed vessel (R/V Thunder or equivalent) is about 70 x 20 ft in 
size. The airgun and streamer, sidescan sonar, and magnetometer will be 
deployed from the vessel. The multibeam echosounder and subbottom 
profiler will be hull-mounted. No equipment will be placed on the sea 
floor as part of survey activities.
    The survey will acquire data in two phases. During the first phase 
the emphasis is on obtaining shallow geohazard data in the Site Survey 
area (see Figure 1 in BP's application) using an airgun array and a 
towed streamer. During the second phase data will be acquired in both 
the Site Survey and Sonar Survey areas (see Figure 1 in BP's 
application) using the multibeam echosounder, sidescan sonar, subbottom 
profiler, and the magnetometer. Each phase has an expected duration of 
about 7.5 days, based on a 24-hour workday. Between the first and 
second phase the operations will be focused on changing equipment for 
about 5 days.
    2DHR Seismic: High-resolution seismic data acquisition will only 
take place during Phase 1 in the Site Survey area. The 2DHR seismic 
source will consist of one of two potential arrays, each with a 
discharge volume of 30 in\3\ and containing multiple airguns. The first 
array option will have three 10 in\3\ airguns, and the other array 
option will have a 20 in\3\ and a 10 in\3\ airgun. Table 1 in this 
document and BP's application summarizes airgun array specifics for 
each option. A 5 in\3\ airgun will be utilized as the mitigation gun. 
The tow depth will be about 3 ft.
    The receivers will be placed on a streamer that is towed behind the 
source vessel. The streamer will be about 984 ft in length and will 
contain 48 receivers at about 20 ft spacing.
    Seismic data will be acquired on two grids. Grid 1 will contain 
lines spaced at 492 ft with perpendicular 984 ft spaced lines. Grid 2 
will contain approximately 65 ft spaced lines. The total line length of 
both grids will be about 342 miles.
    The vessel will travel with a speed of approximately 3-4 knots. The 
seismic pulse interval is 20.5 ft, which means a shot every 3 to 4 
seconds.

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    Table 1--Proposed 30 in\3\ Airgun Array Configurations and Source
 Signatures as Predicted by the Gundalf Airgun Array Model for 1 m Depth
------------------------------------------------------------------------
                                 30 in\3\ Array        30 in\3\ Array
       Array specifics              option 1              option 2
------------------------------------------------------------------------
Number of guns..............  Three 2000 psi        Two 2000 psi sleeve
                               sleeve airguns (3 x   airguns (1 x 20
                               10 in\3\).            in\3\, 1 x 10
                                                     in\3\).
Zero to peak................  4.89 bar-m (~234 dB   3.62 bar-m (~231 dB
                               re [micro]Pa @1 m).   re 1 [micro]Pa @1
                                                     m).
Peak to peak................  9.75 bar-m (~240 dB   7.04 bar-m (~237 dB
                               re [micro]Pa @1 m).   re 1 [micro]Pa @1
                                                     m).
RMS pressure................  0.28 bar-m (~209 dB   0.22 bar-m (~207 dB
                               re [micro]Pa @1 m).   re 1 [micro]Pa @1
                                                     m).
Dominant frequencies........  About 20-300 Hz.....  About 20-300 Hz.
------------------------------------------------------------------------

    Multibeam Echosounder and Sidescan Sonar: A multibeam echosounder 
and sidescan sonar will be used to obtain high accuracy information 
regarding bathymetry and isonification of the seafloor. For accurate 
object detection, a side scan sonar survey is required to complement a 
multibeam echosounder survey.
    The proposed multibeam echosounder operates at a root mean squared 
(rms) source level of approximately 220 dB re 1 [mu]Pa at 1 m. The 
multibeam echosounder emits high frequency energy in a fan-shaped 
pattern of equidistant or equiangular beam spacing. The beam width of 
the emitted sound energy in the along track direction is 2 degrees at 
200 kilohertz (kHz) and 1 degree at 400 kHz, while the across track 
beam width is 1 degree at 200 kHz and 0.5 degrees at 400 kHz (see Table 
2 in BP's application and this document). The maximum ping rate of the 
multibeam echosounder is 60 Hz.
    The proposed sidescan sonar system will operate at about 100 kHz 
(120 kHz to 135 kHz) and 400 kHz (400 kHz to 450 kHz). The estimated 
rms source level is approximately 215 dB re 1 [mu]Pa at 1 m (Table 2). 
The sound energy is emitted in a narrow fan-shaped pattern, with a 
horizontal beam width of 1.5 degrees for 100 kHz and 0.4 degrees at 400 
kHz, with a vertical beam height of 50 degrees. The maximum ping rate 
of the sidescan sonar is 30 Hz.
    Data acquisition with the multibeam echosounder and sidescan sonar 
data will take place along all grids in the Sonar Survey area. 
Additional multibeam echosounder and sidescan sonar infill lines will 
be added to obtain 150% coverage over certain areas.
    In addition, BP may conduct a strudel scour survey in the 
Kadleroshilik and Sagavanirktok River overflood areas for about 3 days, 
depending on results from reconnaissance flights in June. This data 
would be collected from a separate vessel equipped with a multibeam 
echosounder and sidescan sonar. These units would operate at a 
frequency of about 400 kHz. Because this operating frequency is outside 
the hearing range of marine mammals, the strudel scour survey is not 
part of BP's IHA application and is not analyzed further.
    Subbottom Profiler: The purpose of the subbottom profiler is to 
provide an accurate digital image of the shallow sub-surface sea 
bottom, below the mud line. The proposed system emits energy in the 
frequency bands of 2 to 16 kHz (Table 2). The beam width is 15 to 24 
degrees, depending on the center frequency. Typical pulse rate is 
between 3 and 6 Hz. Subbottom profiler data will be acquired 
continuously along all grids during Phase 2 of the operations (i.e., 
after 2DHR seismic data has been obtained).
    Magnetometer: A marine magnetometer will be used for the detection 
of magnetic deflection generated by geologic features, and buried or 
exposed ferrous objects, which may be related to archaeological 
artifacts or modern man-made debris. The magnetometer will be towed at 
a sufficient distance behind the vessel to avoid data pollution by the 
vessel's magnetic properties. Magnetometers measure changes in magnetic 
fields over the seabed and do not produce sounds. Therefore, this piece 
of equipment is not anticipated to result in the take of marine mammals 
and is not analyzed further in this document.

  Table 2--Source Characteristics of the Proposed Geophysical Survey Equipment of the Liberty Geohazard Survey
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                                                             Along track    Across track     RMS sound pressure
             Equipment               Operating frequency     beam width      beam width            level
----------------------------------------------------------------------------------------------------------------
Multibeam echosounder.............  200-400 kHz..........        1-2[deg]      0.5-1[deg]  ~220 dB re 1 [mu]Pa
                                                                                            @1m.
Sidescan sonar....................  120-135 kHz..........        1.5[deg]         50[deg]  ~215 dB re 1 [mu]Pa
                                    400-450 kHz..........        0.4[deg]         50[deg]   @1m.
Subbottom profiler................  2-16 kHz.............      15-24[deg]      15-24[deg]  ~216 dB re 1 [mu]Pa
                                                                                            @1m.
----------------------------------------------------------------------------------------------------------------

Description of Marine Mammals in the Area of the Specified Activity

    The Beaufort Sea supports a diverse assemblage of marine mammals. 
Table 3 lists the 12 marine mammal species under NMFS jurisdiction with 
confirmed or possible occurrence in the proposed project area.

                        Table 3--Marine Mammal Species With Confirmed or Possible Occurrence in the Proposed Seismic Survey Area
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           Common name              Scientific name           Status            Occurrence          Seasonality            Range            Abundance
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontocetes.....................  Delphinapterus       ...................  Common............  Mostly spring and   Russia to Canada..            39,258
Beluga whale (Beaufort Sea         leucas.                                                       fall with some in
 stock).                                                                                         summer.

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Killer whale....................  Orcinus orca.......  ...................  Occasional/         Mostly summer and   California to                    552
                                                                             Extralimital.       early fall.         Alaska.
Harbor porpoise.................  Phocoena phocoena..  ...................  Occasional/         Mostly summer and   California to                 48,215
                                                                             Extralimital.       early fall.         Alaska.
Narwhal.........................  Monodon monoceros..  ...................  ..................  ..................  ..................            45,358
Mysticetes......................  Balaena mysticetus.  Endangered;          Common............  Mostly spring and   Russia to Canada..            16,892
Bowhead whale...................                        Depleted.                                fall with some in
                                                                                                 summer.
Gray whale......................  Eschrichtius         ...................  Somewhat common...  Mostly summer.....  Mexico to the U.S.            19,126
                                   robustus.                                                                         Arctic Ocean.
Minke whale.....................  Balaenoptera         ...................  ..................  ..................  ..................         810-1,003
                                   acutorostrata.
Humpback whale (Central North     Megaptera            Endangered;          ..................  ..................  ..................            21,063
 Pacific stock).                   novaeangliae.        Depleted.
Pinnipeds.......................  Erigathus barbatus.  Threatened;          Common............  Spring and summer.  Bering, Chukchi,             155,000
Bearded seal (Beringia distinct                         Depleted.                                                    and Beaufort Seas.
 population segment).
Ringed seal (Arctic stock)......  Phoca hispida......  Threatened;          Common............  Year round........  Bering, Chukchi,             300,000
                                                        Depleted.                                                    and Beaufort Seas.
Spotted seal....................  Phoca largha.......  ...................  Common............  Summer............  Japan to U.S.                141,479
                                                                                                                     Arctic Ocean.
Ribbon seal.....................  Histriophoca         Species of concern.  Occasional........  Summer............  Russia to U.S.                49,000
                                   fasciata.                                                                         Arctic Ocean.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Endangered, threatened, or species of concern under the Endangered Species Act (ESA); Depleted under the MMPA.

    The highlighted (grayed out) species in Table 3 are so rarely 
sighted in the central Alaskan Beaufort Sea that their presence in the 
proposed project area, and therefore take, is unlikely. Minke whales 
are relatively common in the Bering and southern Chukchi seas and have 
recently also been sighted in the northeastern Chukchi Sea (Aerts et 
al., 2013; Clarke et al., 2013). Minke whales are rare in the Beaufort 
Sea. They have not been reported in the Beaufort Sea during the Bowhead 
Whale Aerial Survey Project/Aerial Surveys of Arctic Marine Mammals 
(BWASP/ASAMM) surveys (Clarke et al., 2011, 2012; 2013; Monnet and 
Treacy, 2005), and there was only one observation in 2007 during 
vessel-based surveys in the region (Funk et al., 2010). Humpback whales 
have not generally been found in the Arctic Ocean. However, subsistence 
hunters have spotted humpback whales in low numbers around Barrow, and 
there have been several confirmed sightings of humpback whales in the 
northeastern Chukchi Sea in recent years (Aerts et al., 2013; Clarke et 
al., 2013). The first confirmed sighting of a humpback whale in the 
Beaufort Sea was recorded in August 2007 (Hashagen et al., 2009) when a 
cow and calf were observed 54 mi east of Point Barrow. No additional 
sightings have been documented in the Beaufort Sea. Narwhal are common 
in the waters of northern Canada, west Greenland, and in the European 
Arctic, but rarely occur in the Beaufort Sea (COSEWIC, 2004). Only a 
handful of sightings have occurred in Alaskan waters (Allen and 
Angliss, 2013). These three species are not considered further in this 
proposed IHA notice. Both the walrus and the polar bear could occur in 
the U.S. Beaufort Sea; however, these species are managed by the U.S. 
Fish and Wildlife Service (USFWS) and are not considered further in 
this Notice of Proposed IHA.
    The Beaufort Sea is a main corridor of the bowhead whale migration 
route. The main migration periods occur in spring from April to June 
and in fall from late August/early September through October to early 
November. During the fall migration, several locations in the U.S. 
Beaufort Sea serve as feeding grounds for bowhead whales. Small numbers 
of bowhead whales that remain in the U.S. Arctic Ocean during summer 
also feed in these areas. The U.S. Beaufort Sea is not a main feeding 
or calving area for any other cetacean species. Ringed seals breed and 
pup in the Beaufort Sea; however, this does not occur during the summer 
or early fall. Further information on the biology and local 
distribution of these species can be found in BP's application (see 
ADDRESSES) and the NMFS Marine Mammal Stock Assessment Reports, which 
are available online at: https://www.nmfs.noaa.gov/pr/species/.

Potential Effects of the Specified Activity on Marine Mammals

    This section includes a summary and discussion of the ways that the 
types of stressors associated with the specified activity (e.g., 
seismic airgun, sidescan sonar, subbottom profiler, vessel movement) 
have been observed to or are thought to impact marine mammals. This 
section may include a discussion of known effects that do not rise to 
the level of an MMPA take (for example, with acoustics, we may include 
a discussion of studies that showed animals not reacting at all to 
sound or exhibiting barely measurable avoidance). The discussion may 
also include reactions that we consider to rise to the level of a take 
and those that we do not consider to rise to the level of a take. This 
section is intended as a background of potential effects and does not 
consider either the specific manner in which this activity will be 
carried out or the mitigation that will be implemented or how either of 
those will shape the anticipated impacts from this specific activity. 
The ``Estimated Take by Incidental Harassment'' section later in this 
document will include a

[[Page 21526]]

quantitative analysis of the number of individuals that are expected to 
be taken by this activity. The ``Negligible Impact Analysis'' section 
will include the analysis of how this specific activity will impact 
marine mammals and will consider the content of this section, the 
``Estimated Take by Incidental Harassment'' section, the ``Mitigation'' 
section, and the ``Anticipated Effects on Marine Mammal Habitat'' 
section to draw conclusions regarding the likely impacts of this 
activity on the reproductive success or survivorship of individuals and 
from that on the affected marine mammal populations or stocks.

Background on Sound

    Sound is a physical phenomenon consisting of minute vibrations that 
travel through a medium, such as air or water, and is generally 
characterized by several variables. Frequency describes the sound's 
pitch and is measured in hertz (Hz) or kilohertz (kHz), while sound 
level describes the sound's intensity and is measured in decibels (dB). 
Sound level increases or decreases exponentially with each dB of 
change. The logarithmic nature of the scale means that each 10-dB 
increase is a 10-fold increase in acoustic power (and a 20-dB increase 
is then a 100-fold increase in power). A 10-fold increase in acoustic 
power does not mean that the sound is perceived as being 10 times 
louder, however. Sound levels are compared to a reference sound 
pressure (micro-Pascal) to identify the medium. For air and water, 
these reference pressures are ``re: 20 [micro]Pa'' and ``re: 1 
[micro]Pa,'' respectively. Root mean square (RMS) is the quadratic mean 
sound pressure over the duration of an impulse. RMS is calculated by 
squaring all of the sound amplitudes, averaging the squares, and then 
taking the square root of the average (Urick, 1975). RMS accounts for 
both positive and negative values; squaring the pressures makes all 
values positive so that they may be accounted for in the summation of 
pressure levels (Hastings and Popper, 2005). This measurement is often 
used in the context of discussing behavioral effects, in part, because 
behavioral effects, which often result from auditory cues, may be 
better expressed through averaged units rather than by peak pressures.

Acoustic Impacts

    When considering the influence of various kinds of sound on the 
marine environment, it is necessary to understand that different kinds 
of marine life are sensitive to different frequencies of sound. Based 
on available behavioral data, audiograms have been derived using 
auditory evoked potentials, anatomical modeling, and other data, 
Southall et al. (2007) designate ``functional hearing groups'' for 
marine mammals and estimate the lower and upper frequencies of 
functional hearing of the groups. The functional groups and the 
associated frequencies are indicated below (though animals are less 
sensitive to sounds at the outer edge of their functional range and 
most sensitive to sounds of frequencies within a smaller range 
somewhere in the middle of their functional hearing range):
     Low frequency cetaceans (13 species of mysticetes): 
Functional hearing is estimated to occur between approximately 7 Hz and 
30 kHz;
     Mid-frequency cetaceans (32 species of dolphins, six 
species of larger toothed whales, and 19 species of beaked and 
bottlenose whales): Functional hearing is estimated to occur between 
approximately 150 Hz and 160 kHz;
     High frequency cetaceans (eight species of true porpoises, 
six species of river dolphins, Kogia, the franciscana, and four species 
of cephalorhynchids): Functional hearing is estimated to occur between 
approximately 200 Hz and 180 kHz;
     Phocid pinnipeds in Water: Functional hearing is estimated 
to occur between approximately 75 Hz and 100 kHz; and
     Otariid pinnipeds in Water: Functional hearing is 
estimated to occur between approximately 100 Hz and 40 kHz.
    As mentioned previously in this document, nine marine mammal 
species (five cetaceans and four phocid pinnipeds) may occur in the 
proposed seismic survey area. Of the five cetacean species likely to 
occur in the proposed project area and for which take is requested, two 
are classified as low-frequency cetaceans (i.e., bowhead and gray 
whales), two are classified as mid-frequency cetaceans (i.e., beluga 
and killer whales), and one is classified as a high-frequency cetacean 
(i.e., harbor porpoise) (Southall et al., 2007). A species functional 
hearing group is a consideration when we analyze the effects of 
exposure to sound on marine mammals.
1. Tolerance
    Numerous studies have shown that underwater sounds from industry 
activities are often readily detectable by marine mammals in the water 
at distances of many kilometers. Numerous studies have also shown that 
marine mammals at distances more than a few kilometers away often show 
no apparent response to industry activities of various types (Miller et 
al., 2005; Bain and Williams, 2006). This is often true even in cases 
when the sounds must be readily audible to the animals based on 
measured received levels and the hearing sensitivity of that mammal 
group. Although various baleen whales, toothed whales, and (less 
frequently) pinnipeds have been shown to react behaviorally to 
underwater sound such as airgun pulses or vessels under some 
conditions, at other times mammals of all three types have shown no 
overt reactions (e.g., Malme et al., 1986; Richardson et al., 1995; 
Madsen and Mohl, 2000; Croll et al., 2001; Jacobs and Terhune, 2002; 
Madsen et al., 2002; Miller et al., 2005). Weir (2008) observed marine 
mammal responses to seismic pulses from a 24 airgun array firing a 
total volume of either 5,085 in\3\ or 3,147 in\3\ in Angolan waters 
between August 2004 and May 2005. Weir recorded a total of 207 
sightings of humpback whales (n = 66), sperm whales (n = 124), and 
Atlantic spotted dolphins (n = 17) and reported that there were no 
significant differences in encounter rates (sightings/hr) for humpback 
and sperm whales according to the airgun array's operational status 
(i.e., active versus silent). The airgun arrays used in the Weir (2008) 
study were much larger than the array proposed for use during this 
proposed survey (total discharge volume of 30 in\3\). In general, 
pinnipeds and small odontocetes seem to be more tolerant of exposure to 
some types of underwater sound than are baleen whales. Richardson et 
al. (1995) found that vessel noise does not seem to strongly affect 
pinnipeds that are already in the water. Richardson et al. (1995) went 
on to explain that seals on haul-outs sometimes respond strongly to the 
presence of vessels and at other times appear to show considerable 
tolerance of vessels.
2. Masking
    Masking is the obscuring of sounds of interest by other sounds, 
often at similar frequencies. Marine mammals use acoustic signals for a 
variety of purposes, which differ among species, but include 
communication between individuals, navigation, foraging, reproduction, 
avoiding predators, and learning about their environment (Erbe and 
Farmer, 2000; Tyack, 2000). Masking, or auditory interference, 
generally occurs when sounds in the environment are louder than, and of 
a similar frequency as, auditory signals an animal is trying to 
receive. Masking is a phenomenon that affects animals that

[[Page 21527]]

are trying to receive acoustic information about their environment, 
including sounds from other members of their species, predators, prey, 
and sounds that allow them to orient in their environment. Masking 
these acoustic signals can disturb the behavior of individual animals, 
groups of animals, or entire populations.
    Masking occurs when anthropogenic sounds and signals (that the 
animal utilizes) overlap at both spectral and temporal scales. For the 
airgun sound generated from the proposed seismic survey, sound will 
consist of low frequency (under 500 Hz) pulses with extremely short 
durations (less than one second). Lower frequency man-made sounds are 
more likely to affect detection of communication calls and other 
potentially important natural sounds such as surf and prey noise. There 
is little concern regarding masking near the sound source due to the 
brief duration of these pulses and relatively longer silence between 
airgun shots (approximately 3-4 seconds). However, at long distances 
(over tens of kilometers away), due to multipath propagation and 
reverberation, the durations of airgun pulses can be ``stretched'' to 
seconds with long decays (Madsen et al., 2006), although the intensity 
of the sound is greatly reduced.
    This could affect communication signals used by low frequency 
mysticetes when they occur near the noise band and thus reduce the 
communication space of animals (e.g., Clark et al., 2009) and cause 
increased stress levels (e.g., Foote et al., 2004; Holt et al., 2009). 
Marine mammals are thought to be able to compensate for masking by 
adjusting their acoustic behavior by shifting call frequencies, and/or 
increasing call volume and vocalization rates. For example, blue whales 
are found to increase call rates when exposed to seismic survey noise 
in the St. Lawrence Estuary (Di Iorio and Clark, 2010). The North 
Atlantic right whales exposed to high shipping noise increase call 
frequency (Parks et al., 2007), while some humpback whales respond to 
low-frequency active sonar playbacks by increasing song length (Miller 
el al., 2000). Bowhead whale calls are frequently detected in the 
presence of seismic pulses, although the number of calls detected may 
sometimes be reduced (Richardson et al., 1986; Greene et al., 1999), 
possibly because animals moved away from the sound source or ceased 
calling (Blackwell et al., 2013). Additionally, beluga whales have been 
known to change their vocalizations in the presence of high background 
noise possibly to avoid masking calls (Au et al., 1985; Lesage et al., 
1999; Scheifele et al., 2005). Although some degree of masking is 
inevitable when high levels of manmade broadband sounds are introduced 
into the sea, marine mammals have evolved systems and behavior that 
function to reduce the impacts of masking. Structured signals, such as 
the echolocation click sequences of small toothed whales, may be 
readily detected even in the presence of strong background noise 
because their frequency content and temporal features usually differ 
strongly from those of the background noise (Au and Moore, 1988, 1990). 
The components of background noise that are similar in frequency to the 
sound signal in question primarily determine the degree of masking of 
that signal.
    Redundancy and context can also facilitate detection of weak 
signals. These phenomena may help marine mammals detect weak sounds in 
the presence of natural or manmade noise. Most masking studies in 
marine mammals present the test signal and the masking noise from the 
same direction. The sound localization abilities of marine mammals 
suggest that, if signal and noise come from different directions, 
masking would not be as severe as the usual types of masking studies 
might suggest (Richardson et al., 1995). The dominant background noise 
may be highly directional if it comes from a particular anthropogenic 
source such as a ship or industrial site. Directional hearing may 
significantly reduce the masking effects of these sounds by improving 
the effective signal-to-noise ratio. In the cases of higher frequency 
hearing by the bottlenose dolphin, beluga whale, and killer whale, 
empirical evidence confirms that masking depends strongly on the 
relative directions of arrival of sound signals and the masking noise 
(Penner et al., 1986; Dubrovskiy, 1990; Bain et al., 1993; Bain and 
Dahlheim, 1994). Toothed whales, and probably other marine mammals as 
well, have additional capabilities besides directional hearing that can 
facilitate detection of sounds in the presence of background noise. 
There is evidence that some toothed whales can shift the dominant 
frequencies of their echolocation signals from a frequency range with a 
lot of ambient noise toward frequencies with less noise (Au et al., 
1974, 1985; Moore and Pawloski, 1990; Thomas and Turl, 1990; Romanenko 
and Kitain, 1992; Lesage et al., 1999). A few marine mammal species are 
known to increase the source levels or alter the frequency of their 
calls in the presence of elevated sound levels (Dahlheim, 1987; Au, 
1993; Lesage et al., 1993, 1999; Terhune, 1999; Foote et al., 2004; 
Parks et al., 2007, 2009; Di Iorio and Clark, 2009; Holt et al., 2009).
    These data demonstrating adaptations for reduced masking pertain 
mainly to the very high frequency echolocation signals of toothed 
whales. There is less information about the existence of corresponding 
mechanisms at moderate or low frequencies or in other types of marine 
mammals. For example, Zaitseva et al. (1980) found that, for the 
bottlenose dolphin, the angular separation between a sound source and a 
masking noise source had little effect on the degree of masking when 
the sound frequency was 18 kHz, in contrast to the pronounced effect at 
higher frequencies. Directional hearing has been demonstrated at 
frequencies as low as 0.5-2 kHz in several marine mammals, including 
killer whales (Richardson et al., 1995). This ability may be useful in 
reducing masking at these frequencies. In summary, high levels of sound 
generated by anthropogenic activities may act to mask the detection of 
weaker biologically important sounds by some marine mammals. This 
masking may be more prominent for lower frequencies. For higher 
frequencies, such as that used in echolocation by toothed whales, 
several mechanisms are available that may allow them to reduce the 
effects of such masking.
3. Behavioral Disturbance
    Marine mammals may behaviorally react when exposed to anthropogenic 
sound. These behavioral reactions are often shown as: changing 
durations of surfacing and dives, number of blows per surfacing, or 
moving direction and/or speed; reduced/increased vocal activities; 
changing/cessation of certain behavioral activities (such as 
socializing or feeding); visible startle response or aggressive 
behavior (such as tail/fluke slapping or jaw clapping); avoidance of 
areas where sound sources are located; and/or flight responses (e.g., 
pinnipeds flushing into water from haulouts or rookeries).
    The biological significance of many of these behavioral 
disturbances is difficult to predict, especially if the detected 
disturbances appear minor. However, the consequences of behavioral 
modification have the potential to be biologically significant if the 
change affects growth, survival, or reproduction. Examples of 
significant behavioral modifications include:
     Drastic change in diving/surfacing patterns (such as those 
thought to be causing beaked whale stranding due to

[[Page 21528]]

exposure to military mid-frequency tactical sonar);
     Habitat abandonment due to loss of desirable acoustic 
environment; and
     Cessation of feeding or social interaction.
    The onset of behavioral disturbance from anthropogenic noise 
depends on both external factors (characteristics of noise sources and 
their paths) and the receiving animals (hearing, motivation, 
experience, demography, current activity, reproductive state) and is 
also difficult to predict (Gordon et al., 2004; Southall et al., 2007; 
Ellison et al., 2011).
    Mysticetes: Baleen whales generally tend to avoid operating 
airguns, but avoidance radii are quite variable. Whales are often 
reported to show no overt reactions to pulses from large arrays of 
airguns at distances beyond a few kilometers, even though the airgun 
pulses remain well above ambient noise levels out to much greater 
distances (Miller et al., 2005). However, baleen whales exposed to 
strong noise pulses often react by deviating from their normal 
migration route (Richardson et al., 1999). Migrating gray and bowhead 
whales were observed avoiding the sound source by displacing their 
migration route to varying degrees but within the natural boundaries of 
the migration corridors (Schick and Urban, 2000; Richardson et al., 
1999; Malme et al., 1983). Baleen whale responses to pulsed sound 
however may depend on the type of activity in which the whales are 
engaged. Some evidence suggests that feeding bowhead whales may be more 
tolerant of underwater sound than migrating bowheads (Miller et al., 
2005; Lyons et al., 2009; Christie et al., 2010).
    Results of studies of gray, bowhead, and humpback whales have 
determined that received levels of pulses in the 160-170 dB re 1 [mu]Pa 
rms range seem to cause obvious avoidance behavior in a substantial 
fraction of the animals exposed. In many areas, seismic pulses from 
large arrays of airguns diminish to those levels at distances ranging 
from 2.8-9 mi (4.5-14.5 km) from the source. For the much smaller 
airgun array used during BP's proposed survey (total discharge volume 
of 30 in\3\), the distance to received levels in the 160 dB re 1 [mu]Pa 
rms range is estimated to be 1 mi (1.6 km). Baleen whales within those 
distances may show avoidance or other strong disturbance reactions to 
the airgun array. Subtle behavioral changes sometimes become evident at 
somewhat lower received levels, and recent studies have shown that some 
species of baleen whales, notably bowhead and humpback whales, at times 
show strong avoidance at received levels lower than 160-170 dB re 1 
[mu]Pa rms. Bowhead whales migrating west across the Alaskan Beaufort 
Sea in autumn, in particular, are unusually responsive, with avoidance 
occurring out to distances of 12.4-18.6 mi (20-30 km) from a medium-
sized airgun source (Miller et al., 1999; Richardson et al., 1999). 
However, more recent research on bowhead whales (Miller et al., 2005) 
corroborates earlier evidence that, during the summer feeding season, 
bowheads are not as sensitive to seismic sources. In summer, bowheads 
typically begin to show avoidance reactions at a received level of 
about 160-170 dB re 1 [mu]Pa rms (Richardson et al., 1986; Ljungblad et 
al., 1988; Miller et al., 2005).
    Malme et al. (1986, 1988) studied the responses of feeding eastern 
gray whales to pulses from a single 100 in\3\ airgun off St. Lawrence 
Island in the northern Bering Sea. They estimated, based on small 
sample sizes, that 50% of feeding gray whales ceased feeding at an 
average received pressure level of 173 dB re 1 [mu]Pa on an 
(approximate) rms basis, and that 10% of feeding whales interrupted 
feeding at received levels of 163 dB. Those findings were generally 
consistent with the results of experiments conducted on larger numbers 
of gray whales that were migrating along the California coast and on 
observations of the distribution of feeding Western Pacific gray whales 
off Sakhalin Island, Russia, during a seismic survey (Yazvenko et al., 
2007).
    Data on short-term reactions (or lack of reactions) of cetaceans to 
impulsive noises do not necessarily provide information about long-term 
effects. While it is not certain whether impulsive noises affect 
reproductive rate or distribution and habitat use in subsequent days or 
years, certain species have continued to use areas ensonified by 
airguns and have continued to increase in number despite successive 
years of anthropogenic activity in the area. Gray whales continued to 
migrate annually along the west coast of North America despite 
intermittent seismic exploration and much ship traffic in that area for 
decades (Appendix A in Malme et al., 1984). Bowhead whales continued to 
travel to the eastern Beaufort Sea each summer despite seismic 
exploration in their summer and autumn range for many years (Richardson 
et al., 1987). Populations of both gray whales and bowhead whales grew 
substantially during this time. In any event, the proposed survey will 
occur in summer (July through late August) when most bowhead whales are 
commonly feeding in the Mackenzie River Delta, Canada.
    Patenaude et al. (2002) reported fewer behavioral responses to 
aircraft overflights by bowhead compared to beluga whales. Behaviors 
classified as reactions consisted of short surfacings, immediate dives 
or turns, changes in behavior state, vigorous swimming, and breaching. 
Most bowhead reaction resulted from exposure to helicopter activity and 
little response to fixed-wing aircraft was observed. Most reactions 
occurred when the helicopter was at altitudes <=492 ft (150 m) and 
lateral distances <=820 ft (250 m; Nowacek et al., 2007).
    During their study, Patenaude et al. (2002) observed one bowhead 
whale cow-calf pair during four passes totaling 2.8 hours of the 
helicopter and two pairs during Twin Otter overflights. All of the 
helicopter passes were at altitudes of 49-98 ft (15-30 m). The mother 
dove both times she was at the surface, and the calf dove once out of 
the four times it was at the surface. For the cow-calf pair sightings 
during Twin Otter overflights, the authors did not note any behaviors 
specific to those pairs. Rather, the reactions of the cow-calf pairs 
were lumped with the reactions of other groups that did not consist of 
calves.
    Richardson et al. (1995) and Moore and Clarke (2002) reviewed a few 
studies that observed responses of gray whales to aircraft. Cow-calf 
pairs were quite sensitive to a turboprop survey flown at 1,000 ft (305 
m) altitude on the Alaskan summering grounds. In that survey, adults 
were seen swimming over the calf, or the calf swam under the adult 
(Ljungblad et al., 1983, cited in Richardson et al., 1995 and Moore and 
Clarke, 2002). However, when the same aircraft circled for more than 10 
minutes at 1,050 ft (320 m) altitude over a group of mating gray 
whales, no reactions were observed (Ljungblad et al., 1987, cited in 
Moore and Clarke, 2002). Malme et al. (1984, cited in Richardson et 
al., 1995 and Moore and Clarke, 2002) conducted playback experiments on 
migrating gray whales. They exposed the animals to underwater noise 
recorded from a Bell 212 helicopter (estimated altitude = 328 ft [100 
m]), at an average of three simulated passes per minute. The authors 
observed that whales changed their swimming course and sometimes slowed 
down in response to the playback sound but proceeded to migrate past 
the transducer. Migrating gray whales did not react overtly to a Bell 
212 helicopter at greater than 1,394 ft (425 m) altitude, occasionally 
reacted when the helicopter was at 1,000-1,198 ft (305-365 m), and 
usually reacted when it was below 825 ft (250 m; Southwest Research 
Associates, 1988, cited in

[[Page 21529]]

Richardson et al., 1995 and Moore and Clarke, 2002). Reactions noted in 
that study included abrupt turns or dives or both. Green et al. (1992, 
cited in Richardson et al., 1995) observed that migrating gray whales 
rarely exhibited noticeable reactions to a straight-line overflight by 
a Twin Otter at 197 ft (60 m) altitude.
    Odontocetes: Few systematic data are available describing reactions 
of toothed whales to noise pulses. However, systematic work on sperm 
whales is underway (Tyack et al., 2003), and there is an increasing 
amount of information about responses of various odontocetes to seismic 
surveys based on monitoring studies (e.g., Stone, 2003; Smultea et al., 
2004; Moulton and Miller, 2005). Miller et al. (2009) conducted at-sea 
experiments where reactions of sperm whales were monitored through the 
use of controlled sound exposure experiments from large airgun arrays 
consisting of 20-guns and 31-guns. Of 8 sperm whales observed, none 
changed their behavior when exposed to either a ramp-up at 4-8 mi (7-13 
km) or full array exposures at 0.6-8 mi (1-13 km).
    Seismic operators and marine mammal observers sometimes see 
dolphins and other small toothed whales near operating airgun arrays, 
but, in general, there seems to be a tendency for most delphinids to 
show some limited avoidance of seismic vessels operating large airgun 
systems. However, some dolphins seem to be attracted to the seismic 
vessel and floats, and some ride the bow wave of the seismic vessel 
even when large arrays of airguns are firing. Nonetheless, there have 
been indications that small toothed whales sometimes move away or 
maintain a somewhat greater distance from the vessel when a large array 
of airguns is operating than when it is silent (e.g., Goold, 1996a,b,c; 
Calambokidis and Osmek, 1998; Stone, 2003). The beluga may be a species 
that (at least in certain geographic areas) shows long-distance 
avoidance of seismic vessels. Aerial surveys during seismic operations 
in the southeastern Beaufort Sea recorded much lower sighting rates of 
beluga whales within 10-20 km (6.2-12.4 mi) of an active seismic 
vessel. These results were consistent with the low number of beluga 
sightings reported by observers aboard the seismic vessel, suggesting 
that some belugas might have been avoiding the seismic operations at 
distances of 10-20 km (6.2-12.4 mi) (Miller et al., 2005).
    Captive bottlenose dolphins and (of more relevance in this project) 
beluga whales exhibit changes in behavior when exposed to strong pulsed 
sounds similar in duration to those typically used in seismic surveys 
(Finneran et al., 2002, 2005). However, the animals tolerated high 
received levels of sound (pk-pk level >200 dB re 1 [mu]Pa) before 
exhibiting aversive behaviors.
    Observers stationed on seismic vessels operating off the United 
Kingdom from 1997-2000 have provided data on the occurrence and 
behavior of various toothed whales exposed to seismic pulses (Stone, 
2003; Gordon et al., 2004). Killer whales were found to be 
significantly farther from large airgun arrays during periods of 
shooting compared with periods of no shooting. The displacement of the 
median distance from the array was approximately 0.5 km (0.3 mi) or 
more. Killer whales also appear to be more tolerant of seismic shooting 
in deeper water.
    Reactions of toothed whales to large arrays of airguns are variable 
and, at least for delphinids, seem to be confined to a smaller radius 
than has been observed for mysticetes. However, based on the limited 
existing evidence, belugas should not be grouped with delphinids in the 
``less responsive'' category.
    Patenaude et al. (2002) reported that beluga whales appeared to be 
more responsive to aircraft overflights than bowhead whales. Changes 
were observed in diving and respiration behavior, and some whales 
veered away when a helicopter passed at <=820 ft (250 m) lateral 
distance at altitudes up to 492 ft (150 m). However, some belugas 
showed no reaction to the helicopter. Belugas appeared to show less 
response to fixed-wing aircraft than to helicopter overflights.
    Pinnipeds: Pinnipeds are not likely to show a strong avoidance 
reaction to the airgun sources proposed for use. Visual monitoring from 
seismic vessels has shown only slight (if any) avoidance of airguns by 
pinnipeds and only slight (if any) changes in behavior. Monitoring work 
in the Alaskan Beaufort Sea during 1996-2001 provided considerable 
information regarding the behavior of Arctic ice seals exposed to 
seismic pulses (Harris et al., 2001; Moulton and Lawson, 2002). These 
seismic projects usually involved arrays of 6 to 16 airguns with total 
volumes of 560 to 1,500 in\3\. The combined results suggest that some 
seals avoid the immediate area around seismic vessels. In most survey 
years, ringed seal sightings tended to be farther away from the seismic 
vessel when the airguns were operating than when they were not (Moulton 
and Lawson, 2002). However, these avoidance movements were relatively 
small, on the order of 100 m (328 ft) to a few hundreds of meters, and 
many seals remained within 100-200 m (328-656 ft) of the trackline as 
the operating airgun array passed by. Seal sighting rates at the water 
surface were lower during airgun array operations than during no-airgun 
periods in each survey year except 1997. Similarly, seals are often 
very tolerant of pulsed sounds from seal-scaring devices (Mate and 
Harvey, 1987; Jefferson and Curry, 1994; Richardson et al., 1995). 
However, initial telemetry work suggests that avoidance and other 
behavioral reactions by two other species of seals to small airgun 
sources may at times be stronger than evident to date from visual 
studies of pinniped reactions to airguns (Thompson et al., 1998). Even 
if reactions of the species occurring in the present study area are as 
strong as those evident in the telemetry study, reactions are expected 
to be confined to relatively small distances and durations, with no 
long-term effects on pinniped individuals or populations.
    Blackwell et al. (2004) observed 12 ringed seals during low-
altitude overflights of a Bell 212 helicopter at Northstar in June and 
July 2000 (9 observations took place concurrent with pipe-driving 
activities). One seal showed no reaction to the aircraft while the 
remaining 11 (92%) reacted, either by looking at the helicopter (n = 
10) or by departing from their basking site (n = 1). Blackwell et al. 
(2004) concluded that none of the reactions to helicopters were strong 
or long lasting, and that seals near Northstar in June and July 2000 
probably had habituated to industrial sounds and visible activities 
that had occurred often during the preceding winter and spring. There 
have been few systematic studies of pinniped reactions to aircraft 
overflights, and most of the available data concern pinnipeds hauled 
out on land or ice rather than pinnipeds in the water (Richardson et 
al., 1995; Born et al., 1999).
4. Threshold Shift (Noise-Induced Loss of Hearing)
    When animals exhibit reduced hearing sensitivity (i.e., sounds must 
be louder for an animal to detect them) following exposure to an 
intense sound or sound for long duration, it is referred to as a noise-
induced threshold shift (TS). An animal can experience temporary 
threshold shift (TTS) or permanent threshold shift (PTS). TTS can last 
from minutes or hours to days (i.e., there is complete recovery), can 
occur in specific frequency ranges (i.e., an animal might only have a 
temporary loss of hearing sensitivity between the frequencies of 1 and 
10 kHz), and can

[[Page 21530]]

be of varying amounts (for example, an animal's hearing sensitivity 
might be reduced initially by only 6 dB or reduced by 30 dB). PTS is 
permanent, but some recovery is possible. PTS can also occur in a 
specific frequency range and amount as mentioned above for TTS.
    The following physiological mechanisms are thought to play a role 
in inducing auditory TS: Effects to sensory hair cells in the inner ear 
that reduce their sensitivity, modification of the chemical environment 
within the sensory cells, residual muscular activity in the middle ear, 
displacement of certain inner ear membranes, increased blood flow, and 
post-stimulatory reduction in both efferent and sensory neural output 
(Southall et al., 2007). The amplitude, duration, frequency, temporal 
pattern, and energy distribution of sound exposure all can affect the 
amount of associated TS and the frequency range in which it occurs. As 
amplitude and duration of sound exposure increase, so, generally, does 
the amount of TS, along with the recovery time. For intermittent 
sounds, less TS could occur than compared to a continuous exposure with 
the same energy (some recovery could occur between intermittent 
exposures depending on the duty cycle between sounds) (Kryter et al., 
1966; Ward, 1997). For example, one short but loud (higher SPL) sound 
exposure may induce the same impairment as one longer but softer sound, 
which in turn may cause more impairment than a series of several 
intermittent softer sounds with the same total energy (Ward, 1997). 
Additionally, though TTS is temporary, prolonged exposure to sounds 
strong enough to elicit TTS, or shorter-term exposure to sound levels 
well above the TTS threshold, can cause PTS, at least in terrestrial 
mammals (Kryter, 1985). Although in the case of the proposed shallow 
geohazard survey, animals are not expected to be exposed to sound 
levels for durations long enough to result in PTS.
    PTS is considered auditory injury (Southall et al., 2007). 
Irreparable damage to the inner or outer cochlear hair cells may cause 
PTS; however, other mechanisms are also involved, such as exceeding the 
elastic limits of certain tissues and membranes in the middle and inner 
ears and resultant changes in the chemical composition of the inner ear 
fluids (Southall et al., 2007).
    Although the published body of scientific literature contains 
numerous theoretical studies and discussion papers on hearing 
impairments that can occur with exposure to a loud sound, only a few 
studies provide empirical information on the levels at which noise-
induced loss in hearing sensitivity occurs in nonhuman animals. For 
marine mammals, published data are limited to the captive bottlenose 
dolphin, beluga, harbor porpoise, and Yangtze finless porpoise 
(Finneran et al., 2000, 2002b, 2003, 2005a, 2007, 2010a, 2010b; 
Finneran and Schlundt, 2010; Lucke et al., 2009; Mooney et al., 2009a, 
2009b; Popov et al., 2011a, 2011b; Kastelein et al., 2012a; Schlundt et 
al., 2000; Nachtigall et al., 2003, 2004). For pinnipeds in water, data 
are limited to measurements of TTS in harbor seals, an elephant seal, 
and California sea lions (Kastak et al., 1999, 2005; Kastelein et al., 
2012b).
    Marine mammal hearing plays a critical role in communication with 
conspecifics, and interpretation of environmental cues for purposes 
such as predator avoidance and prey capture. Depending on the degree 
(elevation of threshold in dB), duration (i.e., recovery time), and 
frequency range of TTS, and the context in which it is experienced, TTS 
can have effects on marine mammals ranging from discountable to serious 
(similar to those discussed in auditory masking, below). For example, a 
marine mammal may be able to readily compensate for a brief, relatively 
small amount of TTS in a non-critical frequency range that occurs 
during a time where ambient noise is lower and there are not as many 
competing sounds present. Alternatively, a larger amount and longer 
duration of TTS sustained during time when communication is critical 
for successful mother/calf interactions could have more serious 
impacts. Also, depending on the degree and frequency range, the effects 
of PTS on an animal could range in severity, although it is considered 
generally more serious because it is a permanent condition. Of note, 
reduced hearing sensitivity as a simple function of aging has been 
observed in marine mammals, as well as humans and other taxa (Southall 
et al., 2007), so we can infer that strategies exist for coping with 
this condition to some degree, though likely not without cost.
    Marine mammals are unlikely to be exposed to received levels of 
seismic pulses strong enough to cause more than slight TTS, and, given 
the higher level of sound necessary to cause PTS, it is even less 
likely that PTS could occur as a result of the proposed shallow 
geohazard survey.
5. Non-Auditory Physical Effects
    Non-auditory physical effects might occur in marine mammals exposed 
to strong underwater sound. Possible types of non-auditory 
physiological effects or injuries that theoretically might occur in 
mammals close to a strong sound source include stress, neurological 
effects, bubble formation, and other types of organ or tissue damage. 
Some marine mammal species (i.e., beaked whales) may be especially 
susceptible to injury and/or stranding when exposed to strong pulsed 
sounds.
    Classic stress responses begin when an animal's central nervous 
system perceives a potential threat to its homeostasis. That perception 
triggers stress responses regardless of whether a stimulus actually 
threatens the animal; the mere perception of a threat is sufficient to 
trigger a stress response (Moberg, 2000; Sapolsky et al., 2005; Seyle, 
1950). Once an animal's central nervous system perceives a threat, it 
mounts a biological response or defense that consists of a combination 
of the four general biological defense responses: Behavioral responses; 
autonomic nervous system responses; neuroendocrine responses; or immune 
responses.
    In the case of many stressors, an animal's first and most 
economical (in terms of biotic costs) response is behavioral avoidance 
of the potential stressor or avoidance of continued exposure to a 
stressor. An animal's second line of defense to stressors involves the 
sympathetic part of the autonomic nervous system and the classical 
``fight or flight'' response, which includes the cardiovascular system, 
the gastrointestinal system, the exocrine glands, and the adrenal 
medulla to produce changes in heart rate, blood pressure, and 
gastrointestinal activity that humans commonly associate with 
``stress.'' These responses have a relatively short duration and may or 
may not have significant long-term effects on an animal's welfare.
    An animal's third line of defense to stressors involves its 
neuroendocrine or sympathetic nervous systems; the system that has 
received the most study has been the hypothalmus-pituitary-adrenal 
system (also known as the HPA axis in mammals or the hypothalamus-
pituitary-interrenal axis in fish and some reptiles). Unlike stress 
responses associated with the autonomic nervous system, virtually all 
neuroendocrine functions that are affected by stress--including immune 
competence, reproduction, metabolism, and behavior--are regulated by 
pituitary hormones. Stress-induced changes in the secretion of 
pituitary hormones have been implicated in failed reproduction (Moberg, 
1987; Rivier, 1995), altered metabolism (Elasser et al., 2000), reduced 
immune competence (Blecha,

[[Page 21531]]

2000), and behavioral disturbance. Increases in the circulation of 
glucocorticosteroids (cortisol, corticosterone, and aldosterone in 
marine mammals; see Romano et al., 2004) have been equated with stress 
for many years.
    The primary distinction between stress (which is adaptive and does 
not normally place an animal at risk) and distress is the biotic cost 
of the response. During a stress response, an animal uses glycogen 
stores that can be quickly replenished once the stress is alleviated. 
In such circumstances, the cost of the stress response would not pose a 
risk to the animal's welfare. However, when an animal does not have 
sufficient energy reserves to satisfy the energetic costs of a stress 
response, energy resources must be diverted from other biotic 
functions, which impair those functions that experience the diversion. 
For example, when mounting a stress response diverts energy away from 
growth in young animals, those animals may experience stunted growth. 
When mounting a stress response diverts energy from a fetus, an 
animal's reproductive success and fitness will suffer. In these cases, 
the animals will have entered a pre-pathological or pathological state 
which is called ``distress'' (sensu Seyle, 1950) or ``allostatic 
loading'' (sensu McEwen and Wingfield, 2003). This pathological state 
will last until the animal replenishes its biotic reserves sufficient 
to restore normal function. Note that these examples involved a long-
term (days or weeks) stress response exposure to stimuli.
    Relationships between these physiological mechanisms, animal 
behavior, and the costs of stress responses have also been documented 
fairly well through controlled experiment; because this physiology 
exists in every vertebrate that has been studied, it is not surprising 
that stress responses and their costs have been documented in both 
laboratory and free-living animals (for examples see, Holberton et al., 
1996; Hood et al., 1998; Jessop et al., 2003; Krausman et al., 2004; 
Lankford et al., 2005; Reneerkens et al., 2002; Thompson and Hamer, 
2000). Although no information has been collected on the physiological 
responses of marine mammals to anthropogenic sound exposure, studies of 
other marine animals and terrestrial animals would lead us to expect 
some marine mammals to experience physiological stress responses and, 
perhaps, physiological responses that would be classified as 
``distress'' upon exposure to anthropogenic sounds.
    For example, Jansen (1998) reported on the relationship between 
acoustic exposures and physiological responses that are indicative of 
stress responses in humans (e.g., elevated respiration and increased 
heart rates). Jones (1998) reported on reductions in human performance 
when faced with acute, repetitive exposures to acoustic disturbance. 
Trimper et al. (1998) reported on the physiological stress responses of 
osprey to low-level aircraft noise while Krausman et al. (2004) 
reported on the auditory and physiology stress responses of endangered 
Sonoran pronghorn to military overflights. Smith et al. (2004a, 2004b) 
identified noise-induced physiological transient stress responses in 
hearing-specialist fish (i.e., goldfish) that accompanied short- and 
long-term hearing losses. Welch and Welch (1970) reported physiological 
and behavioral stress responses that accompanied damage to the inner 
ears of fish and several mammals.
    Hearing is one of the primary senses marine mammals use to gather 
information about their environment and communicate with conspecifics. 
Although empirical information on the relationship between sensory 
impairment (TTS, PTS, and acoustic masking) on marine mammals remains 
limited, we assume that reducing a marine mammal's ability to gather 
information about its environment and communicate with other members of 
its species would induce stress, based on data that terrestrial animals 
exhibit those responses under similar conditions (NRC, 2003) and 
because marine mammals use hearing as their primary sensory mechanism. 
Therefore, we assume that acoustic exposures sufficient to trigger 
onset PTS or TTS would be accompanied by physiological stress 
responses. More importantly, marine mammals might experience stress 
responses at received levels lower than those necessary to trigger 
onset TTS. Based on empirical studies of the time required to recover 
from stress responses (Moberg, 2000), NMFS also assumes that stress 
responses could persist beyond the time interval required for animals 
to recover from TTS and might result in pathological and pre-
pathological states that would be as significant as behavioral 
responses to TTS.
    Resonance effects (Gentry, 2002) and direct noise-induced bubble 
formations (Crum et al., 2005) are implausible in the case of exposure 
to an impulsive broadband source like an airgun array. If seismic 
surveys disrupt diving patterns of deep-diving species, this might 
result in bubble formation and a form of the bends, as speculated to 
occur in beaked whales exposed to sonar. However, there is no specific 
evidence of this upon exposure to airgun pulses. Additionally, no 
beaked whale species occur in the proposed project area.
    In general, very little is known about the potential for strong, 
anthropogenic underwater sounds to cause non-auditory physical effects 
in marine mammals. Such effects, if they occur at all, would presumably 
be limited to short distances and to activities that extend over a 
prolonged period. The available data do not allow identification of a 
specific exposure level above which non-auditory effects can be 
expected (Southall et al., 2007) or any meaningful quantitative 
predictions of the numbers (if any) of marine mammals that might be 
affected in those ways. There is no definitive evidence that any of 
these effects occur even for marine mammals in close proximity to large 
arrays of airguns, which are not proposed for use during this program. 
In addition, marine mammals that show behavioral avoidance of industry 
activities, including bowheads, belugas, and some pinnipeds, are 
especially unlikely to incur non-auditory impairment or other physical 
effects.
6. Stranding and Mortality
    Marine mammals close to underwater detonations of high explosive 
can be killed or severely injured, and the auditory organs are 
especially susceptible to injury (Ketten et al., 1993; Ketten, 1995). 
Airgun pulses are less energetic and their peak amplitudes have slower 
rise times. To date, there is no evidence that serious injury, death, 
or stranding by marine mammals can occur from exposure to airgun 
pulses, even in the case of large airgun arrays. Additionally, BP's 
project will use a very small airgun array in shallow water. NMFS does 
not expect any marine mammals will incur serious injury or mortality in 
the shallow waters of Foggy Island Bay or strand as a result of the 
proposed shallow geohazard survey.
7. Potential Effects From Sonar Systems on Marine Mammals
    The multibeam echosounder proposed for use during BP's survey does 
not produce frequencies within the hearing range of marine mammals. 
Exposure to sounds generated by this instrument, therefore, does not 
present a risk of potential physiological damage, hearing impairment, 
and/or behavioral responses.
    The sidescan sonar does not produce frequencies within the hearing 
range of

[[Page 21532]]

mysticetes and ice seals, but when operating at 110-135 kHz could be 
audible by mid- and high-frequency cetaceans, depending on the strength 
of the signal. However, when it operates at the much higher frequencies 
greater than 400 kHz, it is outside of the hearing range of all marine 
mammals. The signal from side scan sonars is narrow, typically in the 
form of a conical beam projected directly below the vessel. Based on 
previous measurements of a sidescan sonar working at similar 
frequencies in deeper water, distances to sound levels of 190 and 180 
dB re 1 [mu]Pa (rms) were 22 and 47 m, respectively (Warner and 
McCrodan, 2011). It is unlikely that an animal would be exposed for an 
extended time to a signal strong enough for TTS or PTS to occur, unless 
the animal is present within the beam under the vessel and swimming 
with the same speed and direction. The distance at which beluga whales 
could react behaviorally to the sidescan sonar signal is about 200 m 
(Warner and McCrodan, 2011). However, the response, if it occurs at 
all, is expected to be short term. Masking is unlikely to occur due to 
the nature of the signal and because beluga whales and ice seals 
generally vocalize at frequencies lower than 100 kHz.
    Subbottom profilers will be audible to all three hearing classes of 
marine mammals that occur in the project area. Based on previous 
measurements of various subbottom profilers, the rms sound pressure 
level does not reach 180 dB re 1 [mu]Pa (Funk et al., 2008; Ireland et 
al., 2009; Warner and McCrodan, 2011). Distances to sound levels that 
could result in mild behavioral responses, such as avoidance, ranged 
from 1 to 30 m. Masking is unlikely due to the low duty cycle, 
directionality, and brief period when an individual mammal is likely to 
be within the beam. Additionally, the higher frequencies of the 
instrument are unlikely to overlap with the lower frequency calls by 
mysticetes.
    Some stranding events of mid-frequency cetaceans were attributed to 
the presence of sonar surveys in the area (e.g., Southall et al., 
2006). Recently, an independent scientific review panel concluded that 
the mass stranding of approximately 100 melon-headed whales in 
northwest Madagascar in 2008 was primarily triggered by a multibeam 
echosounder system (Southall et al., 2013), acknowledging that it was 
difficult to find evidence showing a direct cause-effect relationships. 
The multibeam echosounder proposed in this survey will operate at much 
higher frequencies, outside the hearing range of any marine mammal. The 
sidescan sonar and subbottom profiler are much less powerful. 
Considering the acoustic specifics of these instruments, the shallow 
water environment, the unlikely presence of toothed whales in the area, 
and planned mitigation measures, no marine mammal stranding or 
mortality are expected.

Vessel Impacts

    Vessel activity and noise associated with vessel activity will 
temporarily increase in the action area during BP's survey as a result 
of the operation of one vessel. To minimize the effects of the vessel 
and noise associated with vessel activity, BP will alter speed if a 
marine mammal gets too close to a vessel. In addition, the vessel will 
be operating at slow speed (3-4 knots) when conducting surveys. Marine 
mammal monitoring observers will alert the vessel captain as animals 
are detected to ensure safe and effective measures are applied to avoid 
coming into direct contact with marine mammals. Therefore, NMFS neither 
anticipates nor authorizes takes of marine mammals from ship strikes.
    McCauley et al. (1996) reported several cases of humpback whales 
responding to vessels in Hervey Bay, Australia. Results indicated clear 
avoidance at received levels between 118 to 124 dB in three cases for 
which response and received levels were observed/measured.
    Palka and Hammond (2001) analyzed line transect census data in 
which the orientation and distance off transect line were reported for 
large numbers of minke whales. The authors developed a method to 
account for effects of animal movement in response to sighting 
platforms. Minor changes in locomotion speed, direction, and/or diving 
profile were reported at ranges from 1,847 to 2,352 ft (563 to 717 m) 
at received levels of 110 to 120 dB.
    Odontocetes, such as beluga whales, killer whales, and harbor 
porpoises, often show tolerance to vessel activity; however, they may 
react at long distances if they are confined by ice, shallow water, or 
were previously harassed by vessels (Richardson et al., 1995). Beluga 
whale response to vessel noise varies greatly from tolerance to extreme 
sensitivity depending on the activity of the whale and previous 
experience with vessels (Richardson et al., 1995). Reactions to vessels 
depends on whale activities and experience, habitat, boat type, and 
boat behavior (Richardson et al., 1995) and may include behavioral 
responses, such as altered headings or avoidance (Blane and Jaakson, 
1994; Erbe and Farmer, 2000); fast swimming; changes in vocalizations 
(Lesage et al., 1999; Scheifele et al., 2005); and changes in dive, 
surfacing, and respiration patterns.
    There are few data published on pinniped responses to vessel 
activity, and most of the information is anecdotal (Richardson et al., 
1995). Generally, sea lions in water show tolerance to close and 
frequently approaching vessels and sometimes show interest in fishing 
vessels. They are less tolerant when hauled out on land; however, they 
rarely react unless the vessel approaches within 100-200 m (330-660 ft; 
reviewed in Richardson et al., 1995).
    The addition of one vessel and noise due to vessel operations 
associated with the survey is not expected to have effects that could 
cause significant or long-term consequences for individual marine 
mammals or their populations.

Anticipated Effects on Marine Mammal Habitat

    The primary potential impacts to marine mammal habitat and other 
marine species are associated with elevated sound levels produced by 
airguns and other active acoustic sources. This section describes the 
potential impacts to marine mammal habitat from the specified activity. 
Because the marine mammals in the area feed on fish and/or 
invertebrates there is also information on the species typically preyed 
upon by the marine mammals in the area.

Common Marine Mammal Prey in the Project Area

    All of the marine mammal species that may occur in the proposed 
project area prey on either marine fish or invertebrates. The ringed 
seal feeds on fish and a variety of benthic species, including crabs 
and shrimp. Bearded seals feed mainly on benthic organisms, primarily 
crabs, shrimp, and clams. Spotted seals feed on pelagic and demersal 
fish, as well as shrimp and cephalopods. They are known to feed on a 
variety of fish including herring, capelin, sand lance, Arctic cod, 
saffron cod, and sculpins. Ribbon seals feed primarily on pelagic fish 
and invertebrates, such as shrimp, crabs, squid, octopus, cod, sculpin, 
pollack, and capelin. Juveniles feed mostly on krill and shrimp.
    Bowhead whales feed in the eastern Beaufort Sea during summer and 
early autumn but continue feeding to varying degrees while on their 
migration through the central and western Beaufort Sea in the late 
summer and fall (Richardson and Thomson [eds.], 2002). When feeding in 
relatively shallow areas, bowheads feed throughout the

[[Page 21533]]

water column. However, feeding is concentrated at depths where 
zooplankton is concentrated (Wursig et al., 1984, 1989; Richardson 
[ed.], 1987; Griffiths et al., 2002). Lowry and Sheffield (2002) found 
that copepods and euphausiids were the most common prey found in 
stomach samples from bowhead whales harvested in the Kaktovik area from 
1979 to 2000. Areas to the east of Barter Island (which is 
approximately 90 mi east of BP's proposed survey area) appear to be 
used regularly for feeding as bowhead whales migrate slowly westward 
across the Beaufort Sea (Thomson and Richardson, 1987; Richardson and 
Thomson [eds.], 2002).
    Recent articles and reports have noted bowhead whales feeding in 
several areas of the U.S. Beaufort Sea. The Barrow area is commonly 
used as a feeding area during spring and fall, with a higher proportion 
of photographed individuals displaying evidence of feeding in fall 
rather than spring (Mocklin, 2009). A bowhead whale feeding ``hotspot'' 
(Okkonen et al., 2011) commonly forms on the western Beaufort Sea shelf 
off Point Barrow in late summer and fall. Favorable conditions 
concentrate euphausiids and copepods, and bowhead whales congregate to 
exploit the dense prey (Ashjian et al., 2010, Moore et al., 2010; 
Okkonen et al., 2011). Surveys have also noted bowhead whales feeding 
in the Camden Bay area during the fall (Koski and Miller, 2009; 
Quakenbush et al., 2010).
    The 2006-2008 BWASP Final Report (Clarke et al., 2011a) and the 
2009 BWASP Final Report (Clarke et al., 2011b) note sightings of 
feeding bowhead whales in the Beaufort Sea during the fall season. 
During that 4 year period, the largest groups of feeding whales were 
sighted between Smith Bay and Point Barrow (hundreds of miles to the 
west of Prudhoe Bay), and none were sighted feeding in Camden Bay 
(Clarke et al., 2011a,b). Clarke and Ferguson (undated) examined the 
raw BWASP data from the years 2000-2009. They noted that feeding 
behavior was noted more often in September than October and that while 
bowheads were observed feeding throughout the study area (which 
includes the entire U.S. Beaufort Sea), sightings were less frequent in 
the central Alaskan Beaufort than they were east of Kaktovik and west 
of Smith Bay. Additionally, Clarke and Ferguson (undated) and Clarke et 
al. (2011b) refer to information from Ashjian et al. (2010), which 
describes the importance of wind-driven currents that produce favorable 
feeding conditions for bowhead whales in the area between Smith Bay and 
Point Barrow. Increased winds in that area may be increasing the 
incidence of upwelling, which in turn may be the reason for increased 
sightings of feeding bowheads in the area. Clarke and Ferguson 
(undated) also note that the incidence of feeding bowheads in the 
eastern Alaskan Beaufort Sea has decreased since the early 1980s.
    Beluga whales feed on a variety of fish, shrimp, squid and octopus 
(Burns and Seaman, 1985). Very few beluga whales occur nearshore; their 
main migration route is much further offshore. Like several of the 
other species in the area, harbor porpoise feed on demersal and benthic 
species, mainly schooling fish and cephalopods. Depending on the type 
of killer whale (transient or resident), they feed on fish and/or 
marine mammals. However, harbor porpoises and killer whales are not 
commonly found in Foggy Island Bay.
    Gray whales are primarily bottom feeders, and benthic amphipods and 
isopods form the majority of their summer diet, at least in the main 
summering areas west of Alaska (Oliver et al., 1983; Oliver and 
Slattery, 1985). Farther south, gray whales have also been observed 
feeding around kelp beds, presumably on mysid crustaceans, and on 
pelagic prey such as small schooling fish and crab larvae (Hatler and 
Darling, 1974). However, the central Beaufort Sea is not known to be a 
primary feeding ground for gray whales.
    Two kinds of fish inhabit marine waters in the study area: (1) True 
marine fish that spend all of their lives in salt water, and (2) 
anadromous species that reproduce in fresh water and spend parts of 
their life cycles in salt water.
    Most arctic marine fish species are small, benthic forms that do 
not feed high in the water column. The majority of these species are 
circumpolar and are found in habitats ranging from deep offshore water 
to water as shallow as 16.4-33 ft (5-10 m; Fechhelm et al., 1995). The 
most important pelagic species, and the only abundant pelagic species, 
is the Arctic cod. The Arctic cod is a major vector for the transfer of 
energy from lower to higher trophic levels (Bradstreet et al., 1986). 
In summer, Arctic cod can form very large schools in both nearshore and 
offshore waters (Craig et al., 1982; Bradstreet et al., 1986). 
Locations and areas frequented by large schools of Arctic cod cannot be 
predicted but can be almost anywhere. The Arctic cod is a major food 
source for beluga whales, ringed seals, and numerous species of 
seabirds (Frost and Lowry, 1984; Bradstreet et al., 1986).
    Anadromous Dolly Varden char and some species of whitefish winter 
in rivers and lakes, migrate to the sea in spring and summer, and 
return to fresh water in autumn. Anadromous fish form the basis of 
subsistence, commercial, and small regional sport fisheries. Dolly 
Varden char migrate to the sea from May through mid-June (Johnson, 
1980) and spend about 1.5-2.5 months there (Craig, 1989). They return 
to rivers beginning in late July or early August with the peak return 
migration occurring between mid-August and early September (Johnson, 
1980). At sea, most anadromous corregonids (whitefish) remain in 
nearshore waters within several kilometers of shore (Craig, 1984, 
1989). They are often termed ``amphidromous'' fish in that they make 
repeated annual migrations into marine waters to feed, returning each 
fall to overwinter in fresh water.
    Benthic organisms are defined as bottom dwelling creatures. 
Infaunal organisms are benthic organisms that live within the substrate 
and are often sedentary or sessile (bivalves, polychaetes). Epibenthic 
organisms live on or near the bottom surface sediments and are mobile 
(amphipods, isopods, mysids, and some polychaetes). Epifauna, which 
live attached to hard substrates, are rare in the Beaufort Sea because 
hard substrates are scarce there. A small community of epifauna, the 
Boulder Patch, occurs in Stefansson Sound.
    Many of the nearshore benthic marine invertebrates of the Arctic 
are circumpolar and are found over a wide range of water depths (Carey 
et al., 1975). Species identified include polychaetes (Spio filicornis, 
Chaetozone setosa, Eteone longa), bivalves (Cryrtodaria kurriana, 
Nucula tenuis, Liocyma fluctuosa), an isopod (Saduria entomon), and 
amphipods (Pontoporeia femorata, P. affinis).
    Nearshore benthic fauna have been studied in Beaufort Sea lagoons 
and near the mouth of the Colville River (Kinney et al., 1971, 1972; 
Crane and Cooney, 1975). The waters of Simpson Lagoon, Harrison Bay, 
and the nearshore region support a number of infaunal species including 
crustaceans, mollusks, and polychaetes. In areas influenced by river 
discharge, seasonal changes in salinity can greatly influence the 
distribution and abundance of benthic organisms. Large fluctuations in 
salinity and temperature that occur over a very short time period, or 
on a seasonal basis, allow only very adaptable, opportunistic species 
to survive (Alexander et al., 1974). Since shorefast ice is present for 
many months, the distribution and abundance of most species depends on

[[Page 21534]]

annual (or more frequent) recolonization from deeper offshore waters 
(Woodward Clyde Consultants, 1995). Due to ice scouring, particularly 
in water depths of less than 8 ft (2.4 m), infaunal communities tend to 
be patchily distributed. Diversity increases with water depth until the 
shear zone is reached at 49-82 ft (15-25 m; Carey, 1978). Biodiversity 
then declines due to ice gouging between the landfast ice and the polar 
pack ice (Woodward Clyde Consultants, 1995).

Potential Impacts From Sound Generation

    With regard to fish as a prey source for odontocetes and seals, 
fish are known to hear and react to sounds and to use sound to 
communicate (Tavolga et al., 1981) and possibly avoid predators (Wilson 
and Dill, 2002). Experiments have shown that fish can sense both the 
strength and direction of sound (Hawkins, 1981). Primary factors 
determining whether a fish can sense a sound signal, and potentially 
react to it, are the frequency of the signal and the strength of the 
signal in relation to the natural background noise level.
    Fishes produce sounds that are associated with behaviors that 
include territoriality, mate search, courtship, and aggression. It has 
also been speculated that sound production may provide the means for 
long distance communication and communication under poor underwater 
visibility conditions (Zelick et al., 1999), although the fact that 
fish communicate at low-frequency sound levels where the masking 
effects of ambient noise are naturally highest suggests that very long 
distance communication would rarely be possible. Fishes have evolved a 
diversity of sound generating organs and acoustic signals of various 
temporal and spectral contents. Fish sounds vary in structure, 
depending on the mechanism used to produce them (Hawkins, 1993). 
Generally, fish sounds are predominantly composed of low frequencies 
(less than 3 kHz).
    Since objects in the water scatter sound, fish are able to detect 
these objects through monitoring the ambient noise. Therefore, fish are 
probably able to detect prey, predators, conspecifics, and physical 
features by listening to environmental sounds (Hawkins, 1981). There 
are two sensory systems that enable fish to monitor the vibration-based 
information of their surroundings. The two sensory systems, the inner 
ear and the lateral line, constitute the acoustico-lateralis system.
    Although the hearing sensitivities of very few fish species have 
been studied to date, it is becoming obvious that the intra- and inter-
specific variability is considerable (Coombs, 1981). Nedwell et al. 
(2004) compiled and published available fish audiogram information. A 
noninvasive electrophysiological recording method known as auditory 
brainstem response is now commonly used in the production of fish 
audiograms (Yan, 2004). Generally, most fish have their best hearing in 
the low-frequency range (i.e., less than 1 kHz). Even though some fish 
are able to detect sounds in the ultrasonic frequency range, the 
thresholds at these higher frequencies tend to be considerably higher 
than those at the lower end of the auditory frequency range.
    Literature relating to the impacts of sound on marine fish species 
can be divided into the following categories: (1) Pathological effects; 
(2) physiological effects; and (3) behavioral effects. Pathological 
effects include lethal and sub-lethal physical damage to fish; 
physiological effects include primary and secondary stress responses; 
and behavioral effects include changes in exhibited behaviors of fish. 
Behavioral changes might be a direct reaction to a detected sound or a 
result of the anthropogenic sound masking natural sounds that the fish 
normally detect and to which they respond. The three types of effects 
are often interrelated in complex ways. For example, some physiological 
and behavioral effects could potentially lead to the ultimate 
pathological effect of mortality. Hastings and Popper (2005) reviewed 
what is known about the effects of sound on fishes and identified 
studies needed to address areas of uncertainty relative to measurement 
of sound and the responses of fishes. Popper et al. (2003/2004) also 
published a paper that reviews the effects of anthropogenic sound on 
the behavior and physiology of fishes.
    Potential effects of exposure to sound on marine fish include TTS, 
physical damage to the ear region, physiological stress responses, and 
behavioral responses such as startle response, alarm response, 
avoidance, and perhaps lack of response due to masking of acoustic 
cues. Most of these effects appear to be either temporary or 
intermittent and therefore probably do not significantly impact the 
fish at a population level. The studies that resulted in physical 
damage to the fish ears used noise exposure levels and durations that 
were far more extreme than would be encountered under conditions 
similar to those expected during BP's proposed survey.
    The level of sound at which a fish will react or alter its behavior 
is usually well above the detection level. Fish have been found to 
react to sounds when the sound level increased to about 20 dB above the 
detection level of 120 dB (Ona, 1988); however, the response threshold 
can depend on the time of year and the fish's physiological condition 
(Engas et al., 1993).
    Investigations of fish behavior in relation to vessel noise (Olsen 
et al., 1983; Ona, 1988; Ona and Godo, 1990) have shown that fish react 
when the sound from the engines and propeller exceeds a certain level. 
Avoidance reactions have been observed in fish such as cod and herring 
when vessels approached close enough that received sound levels are 110 
dB to 130 dB (Nakken, 1992; Olsen, 1979; Ona and Godo, 1990; Ona and 
Toresen, 1988). However, other researchers have found that fish such as 
polar cod, herring, and capeline are often attracted to vessels 
(apparently by the noise) and swim toward the vessel (Rostad et al., 
2006). Typical sound source levels of vessel noise in the audible range 
for fish are 150 dB to 170 dB (Richardson et al., 1995a). In calm 
weather, ambient noise levels in audible parts of the spectrum lie 
between 60 dB to 100 dB.
    Short, sharp sounds can cause overt or subtle changes in fish 
behavior. Chapman and Hawkins (1969) tested the reactions of whiting 
(hake) in the field to an airgun. When the airgun was fired, the fish 
dove from 82 to 180 ft (25 to 55 m) depth and formed a compact layer. 
The whiting dove when received sound levels were higher than 178 dB re 
1 [mu]Pa (Pearson et al., 1992).
    Pearson et al. (1992) conducted a controlled experiment to 
determine effects of strong noise pulses on several species of rockfish 
off the California coast. They used an airgun with a source level of 
223 dB re 1 [mu]Pa. They noted:
     Startle responses at received levels of 200-205 dB re 1 
[mu]Pa and above for two sensitive species, but not for two other 
species exposed to levels up to 207 dB;
     Alarm responses at 177-180 dB for the two sensitive 
species, and at 186 to 199 dB for other species;
     An overall threshold for the above behavioral response at 
about 180 dB;
     An extrapolated threshold of about 161 dB for subtle 
changes in the behavior of rockfish; and
     A return to pre-exposure behaviors within the 20-60 minute 
exposure period.
    In summary, fish often react to sounds, especially strong and/or 
intermittent sounds of low frequency. Sound pulses at received levels 
of 160 dB re 1 [mu]Pa may cause subtle changes in behavior. Pulses at 
levels of 180 dB

[[Page 21535]]

may cause noticeable changes in behavior (Chapman and Hawkins, 1969; 
Pearson et al., 1992; Skalski et al., 1992). It also appears that fish 
often habituate to repeated strong sounds rather rapidly, on time 
scales of minutes to an hour. However, the habituation does not endure, 
and resumption of the strong sound source may again elicit disturbance 
responses from the same fish.
    Some of the fish species found in the Arctic are prey sources for 
odontocetes and pinnipeds. A reaction by fish to sounds produced by 
BP's proposed survey would only be relevant to marine mammals if it 
caused concentrations of fish to vacate the area. Pressure changes of 
sufficient magnitude to cause that type of reaction would probably 
occur only very close to the sound source, if any would occur at all. 
Impacts on fish behavior are predicted to be inconsequential. Thus, 
feeding odontocetes and pinnipeds would not be adversely affected by 
this minimal loss or scattering, if any, of reduced prey abundance.
    Some mysticetes, including bowhead whales, feed on concentrations 
of zooplankton. Some feeding bowhead whales may occur in the Alaskan 
Beaufort Sea in July and August, but feeding bowheads are more likely 
to occur in the area after the cessation of BP's survey operations. 
Reactions of zooplankton to sound are, for the most part, not known. 
Their ability to move significant distances is limited or nil, 
depending on the type of zooplankton. Behavior of zooplankters is not 
expected to be affected by the survey. These animals have exoskeletons 
and no air bladders. Many crustaceans can make sounds, and some 
crustacea and other invertebrates have some type of sound receptor. A 
reaction by zooplankton to sounds produced by the seismic survey would 
only be relevant to whales if it caused concentrations of zooplankton 
to scatter. Pressure changes of sufficient magnitude to cause that type 
of reaction would probably occur only very close to the sound source, 
if any would occur at all. Impacts on zooplankton behavior are 
predicted to be inconsequential. Thus, feeding mysticetes would not be 
adversely affected by this minimal loss or scattering, if any, of 
reduced zooplankton abundance.
    Based on the preceding discussion, the proposed activity is not 
expected to have any habitat-related effects that could cause 
significant or long-term consequences for individual marine mammals or 
their populations.

Proposed Mitigation

    In order to issue an incidental take authorization (ITA) under 
section 101(a)(5)(D) of the MMPA, NMFS must set forth the permissible 
methods of taking pursuant to such activity, and other means of 
effecting the least practicable impact on such species or stock and its 
habitat, paying particular attention to rookeries, mating grounds, and 
areas of similar significance, and on the availability of such species 
or stock for taking for certain subsistence uses (where relevant). 
Later in this document in the ``Proposed Incidental Harassment 
Authorization'' section, NMFS lays out the proposed conditions for 
review, as they would appear in the final IHA (if issued).

Mitigation Measures Proposed by BP

    For the proposed mitigation measures, BP proposed general 
mitigation measures that apply throughout the survey and specific 
mitigation measures that apply to airgun operations. The proposed 
protocols are discussed next and can also be found in Section 11 of 
BP's application (see ADDRESSES).
1. General Mitigation Measures
    These general mitigation measures are proposed to apply at all 
times to the vessel involved in the Liberty geohazard survey. This 
vessel would also operate under an additional set of specific 
mitigation measures during airgun operations (described a bit later in 
this document).
    The general mitigation measures include: (1) Adjusting speed to 
avoid collisions with whales and during periods of low visibility; (2) 
checking the waters immediately adjacent to the vessel to ensure that 
no marine mammals will be injured when the vessel's propellers (or 
screws) are engaged; (3) avoiding concentrations of groups of whales 
and not operating vessels in a way that separates members of a group; 
(4) reducing vessel speeds to less than 10 knots in the presence of 
feeding whales; (5) reducing speed and steering around groups of whales 
if circumstances allow (but never cutting off a whale's travel path) 
and avoiding multiple changes in direction and speed when within 900 ft 
of whales; (6) maintaining an altitude of at least 1,000 ft when flying 
helicopters, except in emergency situations or during take-offs and 
landings; and (7) not hovering or circling with helicopters above or 
within 0.3 mi of groups of whales.
2. Seismic Airgun Mitigation Measures
    BP proposes to establish and monitor Level A harassment exclusion 
zones for all marine mammal species. These zones will be monitored by 
Protected Species Observers (PSOs; more detail later). Should marine 
mammals enter these exclusion zones, the PSOs will call for and 
implement the Suite of mitigation measures described next.
    Ramp-up Procedure: Ramp-up procedures of an airgun array involve a 
step-wise increase in the number of operating airguns until the 
required discharge volume is achieved. The purpose of a ramp-up 
(sometimes referred to as ``soft-start'') is to provide marine mammals 
in the vicinity of the activity the opportunity to leave the area and 
to avoid the potential for injury or impairment of their hearing 
abilities.
    During ramp-up, BP proposes to implement the common procedure of 
doubling the number of operating airguns at 5-minute intervals, 
starting with the smallest gun in the array. Ramp-up of the 30 in\3\ 
array from a shutdown will therefore take 10 min for the three-airgun 
array option and 5 min for the two-airgun array option. First the 
smallest gun in the array will be activated (10 in\3\) and after 5 min, 
the second airgun (10 in\3\ or 20 in\3\). For the three-airgun array, 
an additional 5 min are then required to activate the third 10 in\3\ 
airgun. During ramp-up, the exclusion zone for the full airgun array 
will be observed. The ramp-up procedures will be applied as follows:
    1. A ramp-up, following a cold start, can be applied if the 
exclusion zone has been free of marine mammals for a consecutive 30-
minute period. The entire exclusion zone must have been visible during 
these 30 minutes. If the entire exclusion zone is not visible, then 
ramp-up from a cold start cannot begin.
    2. Ramp-up procedures from a cold start will be delayed if a marine 
mammal is sighted within the exclusion zone during the 30-minute period 
prior to the ramp-up. The delay will last until the marine mammal(s) 
has been observed to leave the exclusion zone or until the animal(s) is 
not sighted for at least 15 minutes (seals) or 30 minutes (cetaceans).
    3. A ramp-up, following a shutdown, can be applied if the marine 
mammal(s) for which the shutdown occurred has been observed to leave 
the exclusion zone or until the animal(s) has not been sighted for at 
least 15 minutes (seals) or 30 minutes (cetaceans). This assumes there 
was a continuous observation effort prior to the shutdown and the 
entire exclusion zone is visible.
    4. If, for any reason, power to the airgun array has been 
discontinued for a period of 10 minutes or more, ramp-up procedures 
need to be implemented. Only if the PSO watch has been suspended, a 30-
minute clearance of the

[[Page 21536]]

exclusion zone is required prior to commencing ramp-up. Discontinuation 
of airgun activity for less than 10 minutes does not require a ramp-up.
    5. The seismic operator and PSOs will maintain records of the times 
when ramp-ups start and when the airgun arrays reach full power.
    Power Down Procedure: A power down is the immediate reduction in 
the number of operating airguns such that the radii of the 190 dB and 
180 dB (rms) zones are decreased to the extent that an observed marine 
mammal is not in the applicable exclusion zone of the full array. For 
this geohazard survey, the operation of one airgun continues during a 
power down. The continued operation of one airgun is intended to (a) 
alert marine mammals to the presence of airgun activity, and (b) retain 
the option of initiating a ramp up to full operations under poor 
visibility conditions.
    1. The array will be immediately powered down whenever a marine 
mammal is sighted approaching close to or within the applicable 
exclusion zone of the full array, but is outside the applicable 
exclusion zone of the single airgun;
    2. Likewise, if a mammal is already within the exclusion zone of 
the full array when first detected, the airgun array will be powered 
down to one operating gun immediately;
    3. If a marine mammal is sighted within or about to enter the 
applicable exclusion zone of the single airgun, it too will be shut 
down; and
    4. Following a power down, ramp-up to the full airgun array will 
not resume until the marine mammal has cleared the applicable exclusion 
zone. The animal will be considered to have cleared the exclusion zone 
if it has been visually observed leaving the exclusion zone of the full 
array, or has not been seen within the zone for 15 minutes (seals) or 
30 minutes (cetaceans).
    Shut-down Procedures: The operating airgun(s) will be shut down 
completely if a marine mammal approaches or enters the 190 or 180 dB 
(rms) exclusion radius of the smallest airgun. Airgun activity will not 
resume until the marine mammal has cleared the applicable exclusion 
radius of the full array. The animal will be considered to have cleared 
the exclusion radius as described above under ramp-up procedures.
    Poor Visibility Conditions: BP plans to conduct 24-hr operations. 
PSOs will not be on duty during ongoing seismic operations during 
darkness, given the very limited effectiveness of visual observation at 
night (there will be no periods of darkness in the survey area until 
mid-August). The proposed provisions associated with operations at 
night or in periods of poor visibility include the following:
     If during foggy conditions, heavy snow or rain, or 
darkness (which may be encountered starting in late August), the full 
180 dB exclusion zone is not visible, the airguns cannot commence a 
ramp-up procedure from a full shut-down; and
     If one or more airguns have been operational before 
nightfall or before the onset of poor visibility conditions, they can 
remain operational throughout the night or poor visibility conditions. 
In this case ramp-up procedures can be initiated, even though the 
exclusion zone may not be visible, on the assumption that marine 
mammals will be alerted by the sounds from the single airgun and have 
moved away.
    BP is aware that available techniques to effectively detect marine 
mammals during limited visibility conditions (darkness, fog, snow, and 
rain) are in need of development and has in recent years supported 
research and field trials intended to improve methods of detecting 
marine mammals under these conditions.

Additional Mitigation Measures Proposed by NMFS

    The mitigation airgun will be operated at approximately one shot 
per minute and will not be operated for longer than three hours in 
duration during daylight hours and good visibility. In cases when the 
next start-up after the turn is expected to be during lowlight or low 
visibility, use of the mitigation airgun may be initiated 30 minutes 
before darkness or low visibility conditions occur and may be operated 
until the start of the next seismic acquisition line. The mitigation 
gun must still be operated at approximately one shot per minute.

Mitigation Conclusions

    NMFS has carefully evaluated BP's proposed mitigation measures and 
considered a range of other measures in the context of ensuring that 
NMFS prescribes 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:
     The manner in which, and the degree to which, the 
successful implementation of the measures are expected to minimize 
adverse impacts to marine mammals;
     The proven or likely efficacy of the specific measure to 
minimize adverse impacts as planned; and
     The practicability of the measure for applicant 
implementation.
    Any mitigation measure(s) prescribed by NMFS should be able to 
accomplish, have a reasonable likelihood of accomplishing (based on 
current science), or contribute to the accomplishment of one or more of 
the general goals listed below:
    1. Avoidance or minimization of injury or death of marine mammals 
wherever possible (goals 2, 3, and 4 may contribute to this goal).
    2. A reduction in the numbers of marine mammals (total number or 
number at biologically important time or location) exposed to received 
levels of seismic airguns, or other activities expected to result in 
the take of marine mammals (this goal may contribute to 1, above, or to 
reducing harassment takes only).
    3. A reduction in the number of times (total number or number at 
biologically important time or location) individuals would be exposed 
to received levels of seismic airguns or other activities expected to 
result in the take of marine mammals (this goal may contribute to 1, 
above, or to reducing harassment takes only).
    4. A reduction in the intensity of exposures (either total number 
or number at biologically important time or location) to received 
levels of seismic airguns or other activities expected to result in the 
take of marine mammals (this goal may contribute to 1, above, or to 
reducing the severity of harassment takes only).
    5. Avoidance or minimization of adverse effects to marine mammal 
habitat, paying special attention to the food base, activities that 
block or limit passage to or from biologically important areas, 
permanent destruction of habitat, or temporary destruction/disturbance 
of habitat during a biologically important time.
    6. For monitoring directly related to mitigation--an increase in 
the probability of detecting marine mammals, thus allowing for more 
effective implementation of the mitigation.
    Based on our evaluation of the applicant's proposed measures, as 
well as other measures considered by NMFS, NMFS has preliminarily 
determined that the proposed mitigation measures provide the means of 
effecting the least practicable impact on marine mammals species or 
stocks and their habitat, paying particular attention to rookeries, 
mating grounds, and areas of similar significance. Proposed measures to

[[Page 21537]]

ensure availability of such species or stock for taking for certain 
subsistence uses are discussed later in this document (see ``Impact on 
Availability of Affected Species or Stock for Taking for Subsistence 
Uses'' section).

Proposed Monitoring and Reporting

    In order to issue an ITA for an activity, section 101(a)(5)(D) of 
the MMPA states that NMFS must set forth ``requirements pertaining to 
the monitoring and reporting of such taking''. The MMPA implementing 
regulations at 50 CFR 216.104(a)(13) indicate that requests for ITAs 
must include the suggested means of accomplishing the necessary 
monitoring and reporting that will result in increased knowledge of the 
species and of the level of taking or impacts on populations of marine 
mammals that are expected to be present in the proposed action area. BP 
submitted information regarding marine mammal monitoring to be 
conducted during seismic operations as part of the IHA application. 
That information can be found in Sections 11 and 13 of the application. 
The monitoring measures may be modified or supplemented based on 
comments or new information received from the public during the public 
comment period.
    Monitoring measures proposed by the applicant or prescribed by NMFS 
should accomplish one or more of the following top-level goals:
    1. An increase in our understanding of the likely occurrence of 
marine mammal species in the vicinity of the action, i.e., presence, 
abundance, distribution, and/or density of species.
    2. An increase in our understanding of the nature, scope, or 
context of the likely exposure of marine mammal species to any of the 
potential stressor(s) associated with the action (e.g. sound or visual 
stimuli), through better understanding of one or more of the following: 
the action itself and its environment (e.g. sound source 
characterization, propagation, and ambient noise levels); the affected 
species (e.g. life history or dive pattern); the likely co-occurrence 
of marine mammal species with the action (in whole or part) associated 
with specific adverse effects; and/or the likely biological or 
behavioral context of exposure to the stressor for the marine mammal 
(e.g. age class of exposed animals or known pupping, calving or feeding 
areas).
    3. An increase in our understanding of how individual marine 
mammals respond (behaviorally or physiologically) to the specific 
stressors associated with the action (in specific contexts, where 
possible, e.g., at what distance or received level).
    4. An increase in our understanding of how anticipated individual 
responses, to individual stressors or anticipated combinations of 
stressors, may impact either: the long-term fitness and survival of an 
individual; or the population, species, or stock (e.g. through effects 
on annual rates of recruitment or survival).
    5. An increase in our understanding of how the activity affects 
marine mammal habitat, such as through effects on prey sources or 
acoustic habitat (e.g., through characterization of longer-term 
contributions of multiple sound sources to rising ambient noise levels 
and assessment of the potential chronic effects on marine mammals).
    6. An increase in understanding of the impacts of the activity on 
marine mammals in combination with the impacts of other anthropogenic 
activities or natural factors occurring in the region.
    7. An increase in our understanding of the effectiveness of 
mitigation and monitoring measures.
    8. An increase in the probability of detecting marine mammals 
(through improved technology or methodology), both specifically within 
the safety zone (thus allowing for more effective implementation of the 
mitigation) and in general, to better achieve the above goals.

Proposed Monitoring Measures

1. Visual Monitoring
    Two observers referred to as PSOs will be present on the vessel. Of 
these two PSOs, one will be on watch at all times to monitor the 190 
and 180 dB exclusion zones for the presence of marine mammals during 
airgun operations. The main objectives of the vessel-based marine 
mammal monitoring are as follows: (1) To implement mitigation measures 
during seismic operations (e.g. course alteration, airgun power down, 
shut-down and ramp-up); and (2) To record all marine mammal data needed 
to estimate the number of marine mammals potentially affected, which 
must be reported to NMFS within 90 days after the survey.
    BP intends to work with experienced PSOs. At least one Alaska 
Native resident, who is knowledgeable about Arctic marine mammals and 
the subsistence hunt, is expected to be included as one of the team 
members aboard the vessel. Before the start of the survey, the vessel 
crew will be briefed on the function of the PSOs, their monitoring 
protocol, and mitigation measures to be implemented.
    At least one observer will monitor for marine mammals at any time 
during daylight hours (there will be no periods of total darkness until 
mid-August). PSOs will be on duty in shifts of a maximum of 4 hours at 
a time, although the exact shift schedule will be established by the 
lead PSO in consultation with the other PSOs.
    The vessel will offer a suitable platform for marine mammal 
observations. Observations will be made from locations where PSOs have 
the best view around the vessel. During daytime, the PSO(s) will scan 
the area around the vessel systematically with reticle binoculars and 
with the naked eye. Because the main purpose of the PSO on board the 
vessel is detecting marine mammals for the implementation of mitigation 
measures according to specific guidelines, BP prefers to keep the 
information to be recorded as concise as possible, allowing the PSO to 
focus on detecting marine mammals. The following information will be 
collected by the PSOs:
     Environmental conditions--consisting of sea state (in 
Beaufort Wind force scale according to NOAA), visibility (in km, with 
10 km indicating the horizon on a clear day), and sun glare (position 
and severity). These will be recorded at the start of each shift, 
whenever there is an obvious change in one or more of the environmental 
variables, and whenever the observer changes shifts;
     Project activity--consisting of airgun operations (on or 
off), number of active guns, line number. This will be recorded at the 
start of each shift, whenever there is an obvious change in project 
activity, and whenever the observer changes shifts; and
     Sighting information--consisting of the species (if 
determinable), group size, position and heading relative to the vessel, 
behavior, movement, and distance relative to the vessel (initial and 
closest approach). These will be recorded upon sighting a marine mammal 
or group of animals.
    When marine mammals in the water are detected within or about to 
enter the designated exclusion zones, the airgun(s) power down or shut-
down procedures will be implemented immediately. To assure prompt 
implementation of power downs and shut-downs, multiple channels of 
communication between the PSOs and the airgun technicians will be 
established. During the power down and shut-down, the PSO(s) will 
continue to maintain watch to determine when the

[[Page 21538]]

animal(s) are outside the exclusion radius. Airgun operations can be 
resumed with a ramp-up procedure (depending on the extent of the power 
down) if the observers have visually confirmed that the animal(s) moved 
outside the exclusion zone, or if the animal(s) were not observed 
within the exclusion zone for 15 minutes (seals) or for 30 minutes 
(cetaceans). Direct communication with the airgun operator will be 
maintained throughout these procedures.
    All marine mammal observations and any airgun power down, shut-
down, and ramp-up will be recorded in a standardized format. Data will 
be entered into or transferred to a custom database. The accuracy of 
the data entry will be verified daily through QA/QC procedures. 
Recording procedures will allow initial summaries of data to be 
prepared during and shortly after the field program, and will 
facilitate transfer of the data to other programs for further 
processing and archiving.
2. Fish and Airgun Sound Monitoring
    BP proposes to conduct research on fish species in relation to 
airgun operations, including prey species important to ice seals, 
during the proposed seismic survey. The Liberty shallow geohazard 
survey, along with another seismic survey BP is conducting this summer 
in Prudhoe Bay, offers a unique opportunity to assess the impacts of 
airgun sounds on fish, specifically on changes in fish abundance in 
fyke nets that have been sampled in the area for more than 30 years. 
The monitoring study would occur over a 2-month period during the open-
water season. During this time, fish are counted and sized every day, 
unless sampling is prevented by weather, the presence of bears, or 
other events. Fish mortality is also noted.
    The fish-sampling period coincides with the shallow geohazard 
survey, resulting in a situation where each of the four fyke nets will 
be exposed to varying daily exposures to airgun sounds. That is, as 
source vessels move back and forth across the project area, fish caught 
in nets will be exposed to different sounds levels at different nets 
each day. To document relationships between fish catch in each fyke net 
and received sound levels, BP will attempt to instrument each fyke net 
location with a recording hydrophone. Recording hydrophones, to the 
extent possible, will have a dynamic range that extends low enough to 
record near ambient sounds and high enough to capture sound levels 
during relatively close approaches by the airgun array (i.e., likely 
levels as high as about 200 dB re 1 uPa). Bandwidth will extend from 
about 10 Hz to at least 500 Hz. In addition, because some fish 
(especially salmonids) are likely to be sensitive to particle velocity 
instead of or in addition to sound pressure level, BP will attempt to 
instrument each fyke net location with a recording particle velocity 
meter. Acoustic and environmental data will be used in statistical 
models to assess relationships between acoustic and fish variables. 
Additional information on the details of the fish monitoring study can 
be found in Section 13.1 of BP's application (see ADDRESSES).

Monitoring Plan Peer Review

    The MMPA requires that monitoring plans be independently peer 
reviewed ``where the proposed activity may affect the availability of a 
species or stock for taking for subsistence uses'' (16 U.S.C. 
1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing 
regulations state, ``Upon receipt of a complete monitoring plan, and at 
its discretion, [NMFS] will either submit the plan to members of a peer 
review panel for review or within 60 days of receipt of the proposed 
monitoring plan, schedule a workshop to review the plan'' (50 CFR 
216.108(d)).
    Because of the extremely short duration of BP's proposed survey, 
the fact that activities will be completed prior to any fall bowhead 
whale subsistence hunts, and that seal hunts occur more than 50 mi from 
the proposed survey activities, NMFS determined that the proposed 
survey did not meet the trigger for requiring an independent peer 
review of the monitoring plan.

Reporting Measures

1. 90-Day Technical Report
    A report will be submitted to NMFS within 90 days after the end of 
the proposed shallow geohazard survey. The report will summarize all 
activities and monitoring results conducted during in-water seismic 
surveys. The Technical Report will include the following:
     Summary of project start and end dates, airgun activity, 
number of guns, and the number and circumstances of implementing ramp-
up, power down, shutdown, and other mitigation actions;
     Summaries of monitoring effort (e.g., total hours, total 
distances, and marine mammal distribution through the study period, 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals);
     Analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare);
     Species composition, occurrence, and distribution of 
marine mammal sightings, including date, water depth, numbers, age/
size/gender categories (if determinable), and group sizes;
     Analyses of the effects of survey operations;
     Sighting rates of marine mammals during periods with and 
without seismic survey activities (and other variables that could 
affect detectability), such as: (i) Initial sighting distances versus 
survey activity state; (ii) closest point of approach versus survey 
activity state; (iii) observed behaviors and types of movements versus 
survey activity state; (iv) numbers of sightings/individuals seen 
versus survey activity state; (v) distribution around the source 
vessels versus survey activity state; and (vi) estimates of exposures 
of marine mammals to Level B harassment thresholds based on presence in 
the 160 dB harassment zone.
2. Fish and Airgun Sound Report
    BP proposes to present the results of the fish and airgun sound 
study to NMFS in a detailed report that will also be submitted to a 
peer reviewed journal for publication, presented at a scientific 
conference, and presented in Barrow and Nuiqsut.
3. Notification of Injured or Dead Marine Mammals
    In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA 
(if issued), such as an injury (Level A harassment), serious injury or 
mortality (e.g., ship-strike, gear interaction, and/or entanglement), 
BP would immediately cease the specified activities and immediately 
report the incident to the Chief of the Permits and Conservation 
Division, Office of Protected Resources, NMFS, and the Alaska Regional 
Stranding Coordinators. The report would include the following 
information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;

[[Page 21539]]

     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with BP to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. BP would not be able to 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    In the event that BP discovers an injured or dead marine mammal, 
and the lead PSO determines that the cause of the injury or death is 
unknown and the death is relatively recent (i.e., in less than a 
moderate state of decomposition as described in the next paragraph), BP 
would immediately report the incident to the Chief of the Permits and 
Conservation Division, Office of Protected Resources, NMFS, and the 
NMFS Alaska Stranding Hotline and/or by email to the Alaska Regional 
Stranding Coordinators. The report would include the same information 
identified in the paragraph above. Activities would be able to continue 
while NMFS reviews the circumstances of the incident. NMFS would work 
with BP to determine whether modifications in the activities are 
appropriate.
    In the event that BP discovers an injured or dead marine mammal, 
and the lead PSO determines that the injury or death is not associated 
with or related to the activities authorized in the IHA (e.g., 
previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), BP would report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the NMFS Alaska Stranding Hotline and/or by email 
to the Alaska Regional Stranding Coordinators, within 24 hours of the 
discovery. BP would provide photographs or video footage (if available) 
or other documentation of the stranded animal sighting to NMFS and the 
Marine Mammal Stranding Network.

Estimated Take by Incidental Harassment

    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]. Only take by Level B behavioral 
harassment of some species is anticipated as a result of the proposed 
shallow geohazard survey. Anticipated impacts to marine mammals are 
associated with noise propagation from the sound sources (e.g., 
airguns, sidescan sonar, and subbottom profiler) used in the survey. No 
take is expected to result from vessel strikes because of the slow 
speed of the vessel (3-4 knots while acquiring seismic data) and 
because of mitigation measures to reduce collisions with marine 
mammals. Additionally, no take is expected to result from helicopter 
operations (if any occur) because of altitude restrictions. No take is 
expected from the multibeam echosounder and when the sidescan sonar is 
operated at frequencies above 400 kHz because the frequencies are 
outside the hearing ranges of marine mammals. Moreover, when the 
sidescan sonar is operated at frequencies of 110-135 kHz, it is outside 
the hearing ranges of low-frequency cetaceans and ice seals. Therefore, 
take has not been estimated from use of these sources for these 
species.
    BP requested take of 11 marine mammal species by Level B 
harassment. However, for reasons mentioned earlier in this document, it 
is highly unlikely that humpback and minke whales would occur in the 
proposed survey area. Therefore, NMFS does not propose to authorize 
take of these two species. The species for which take, by Level B 
harassment only, is proposed include: bowhead, beluga, gray, and killer 
whales; harbor porpoise; and ringed, bearded, spotted, and ribbon 
seals.
    The airguns produce impulsive sounds. The current acoustic 
thresholds used by NMFS to estimate Level B and Level A harassment are 
presented in Table 4.

        Table 4--Current Acoustic Exposure Criteria Used by NMFS
------------------------------------------------------------------------
          Criterion           Criterion definition        Threshold
------------------------------------------------------------------------
Level A Harassment (Injury).  Permanent Threshold   180 dB re 1 microPa-
                               Shift (PTS).          m (cetaceans)/190
                              (Any level above       dB re 1 microPa-m
                               that which is known   (pinnipeds) root
                               to cause TTS).        mean square (rms).
Level B Harassment..........  Behavioral            160 dB re 1 microPa-
                               Disruption (for       m (rms).
                               impulse noises).
Level B Harassment..........  Behavioral            120 dB re 1 microPa-
                               Disruption (for       m (rms).
                               continuous, noise).
------------------------------------------------------------------------

    Section 6 of BP's application contains a description of the 
methodology used by BP to estimate takes by harassment, including 
calculations for the 160 dB (rms) isopleth and marine mammal densities 
in the areas of operation (see ADDRESSES), which is also provided in 
the following sections. NMFS verified BP's methods, and used the 
density and sound isopleth measurements in estimating take. However, as 
noted later in this section, NMFS proposes to authorize the maximum 
number of estimated takes for all species, not just for cetaceans as 
presented by BP in order to ensure that exposure estimates are not 
underestimated for pinnipeds.
    The shallow geohazard survey will take place in two phases and has 
an estimated duration of approximately 20 days, including 5 days 
between the two phases where operations will be focused on changing 
equipment. Data acquisition will be halted at the start of the Cross 
Island fall bowhead whale hunt.
    During phase 1 of the project, 2DHR seismic data will be acquired 
in about 12 mi\2\ of the Site Survey area. The duration is estimated at 
about 7.5 days, based on a continuous 24-hr operation and not including 
downtime.
    During phase 2, data will be acquired in the Site Survey area (11 
mi\2\) and over approximately 5 mi\2\ of the 29 mi\2\ Sonar Survey area 
using the multibeam echosounder, sidescan sonar, subbottom profiler, 
and magnetometer. The total duration of Phase 2 is also expected to be 
7.5 days, based on a continuous 24-hr operation and not including 
downtime.

Marine Mammal Density Estimates

    Most whale species are migratory and therefore show a seasonal 
distribution, with different densities for the summer period (covering 
July and August) and the fall period (covering September and October). 
Seal species in the Beaufort Sea do not show a distinct seasonal

[[Page 21540]]

distribution during the open-water period between July and October. 
Data acquisition of the proposed shallow geohazard survey will only 
take place in summer (before start of Nuiqsut whaling in late August/
early September), so BP estimated only summer densities for this 
proposed IHA. Whale and seal densities in the Beaufort Sea will further 
depend on the presence of sea ice. However, if ice cover within or 
close to the seismic survey area is more than approximately 10%, survey 
activities may not start or will be halted. Densities related to ice 
conditions are therefore not included in the IHA application.
    Spatial differentiation is another important factor for marine 
mammal densities, both in latitudinal and longitudinal gradient. Taking 
into account the shallow water operations of the proposed survey area 
and the associated area of influence, BP used data from the nearshore 
zone of the Beaufort Sea for the calculation of densities, if 
available.
    Density estimates are based on best available data. Because 
available data did not always cover the area of interest, this is 
subject to large temporal and spatial variation, and correction factors 
for perception and availability bias were not always known, there is 
some uncertainty in the data and assumptions used in the estimated 
number of exposures. To provide allowance for these uncertainties, 
maximum density estimates have been provided in addition to average 
density estimates.
1. Beluga Whale Density Estimates
    The 1979-2011 BWASP aerial survey database, available from the NOAA 
Web site (https://www.afsc.noaa.gov/NMML/software/bwasp-comida.php), 
contains a total of 62 belugas (31 sightings) in block 1, which covers 
the nearshore and offshore Prudhoe Bay area. Except for one solitary 
animal in 1992, all these belugas were seen in September or October; 
the months with most aerial survey effort. None of the sightings 
occurred south of 70[deg] N., which is to be expected because beluga 
whales generally travel much farther north (Moore et al., 2000). The 
summer effort in the 1979-2011 database is limited. Therefore, BP 
believes and NMFS agrees that the 2012-2013 data are the best available 
for calculating beluga summer densities (Clarke et al., 2013; https://www.asfc.noaa.gov/nmml/cetacean/bwasp/2013), even though the 2013 daily 
flight summaries posted on NOAA's Web site have not undergone post-
season QA/QC.
    To estimate the density of beluga whales in the Foggy Island Bay 
area, BP used the 2012 on-transect beluga sighting and effort data from 
the ASAMM surveys flown in July and August in the Beaufort Sea. The 
area most applicable to our survey was the area from 140[deg] W.-
154[deg] W. and water depths of 0-20 m (Table 13 in Clarke et al., 
2013). In addition, BP used beluga sighting and effort data of the 2013 
survey, as reported in the daily flight summaries on the NOAA Web site. 
BP intended to only select flights that covered block 1. However, in 
many cases the aerial surveys flown in block 1 also covered blocks 2 
and 10, which were much farther from shore. Because it was difficult to 
determine the survey effort specific to block 1 from the available 
information, BP included the sighting and effort data from block 2 and 
10 in the calculations. BP used the number of individuals counted on 
transect, together with the transect kilometers flown, to calculate 
density estimates (Table 4 in the application and Table 5 here). To 
convert the number of individuals per transect kilometer (ind/km) to a 
density per area (ind/km\2\), BP used the effective strip width (ESW) 
of 0.614 km for belugas calculated from 2008-2012 aerial survey data 
flown with the Commander aircraft (M. Ferguson, NMML, pers. comm., 30 
Oct 2013).

  Table 5--Summary of Beluga Sighting and Effort Data From the 2012 and 2013 ASAMM Aerial Surveys Flown in July
                                         and August in the Beaufort Sea
----------------------------------------------------------------------------------------------------------------
                                                   Effort (ind/
                      Year                              km)           NR. Ind         Ind/km         Ind/km\2\
----------------------------------------------------------------------------------------------------------------
2012............................................            1431               5          0.0035          0.0028
2013............................................            7572              99          0.0131          0.0182
Average.........................................  ..............  ..............  ..............          0.0105
Maximum.........................................  ..............  ..............  ..............          0.0182
Minimum.........................................  ..............  ..............  ..............          0.0028
----------------------------------------------------------------------------------------------------------------

2. Bowhead Whale Density Estimates
    To estimate summer bowhead whale densities, BP used data from the 
2012 and 2013 ASAMM aerial surveys flown in the Beaufort Sea (Clarke et 
al., 2013; www.asfc.noaa.gov/nmml/). The 1979-2011 ASAMM database 
contains only one on-transect bowhead whale sighting during July and 
August (in 2011), likely due to the limited summer survey effort. In 
contrast, the 2012 and 2013 surveys include substantial effort during 
the summer season and are thus considered to be the best available 
data, even though the 2013 daily flight summaries posted on NOAA's Web 
site have not undergone post-season QA/QC.
    To estimate the density of bowhead whales in the Foggy Island Bay 
area, BP used the 2012 on-transect bowhead sighting and effort data 
from surveys flown in July and August in block 1 (Table 4 in Clarke et 
al., 2013). In addition, BP used the on-transect bowhead sighting and 
effort data of the 2013 survey, as reported in the daily flight 
summaries on the NOAA Web site. BP intended to only select flights that 
covered block 1. However, in many cases the aerial surveys flown in 
block 1 also covered blocks 2 and 10, which were much farther from 
shore. Because it was difficult to determine the survey effort specific 
to block 1 from the available information, BP included the sighting and 
effort data from block 2 and 10 in the calculations (Table 5 in the 
application and Table 6 here). To convert the number of individuals per 
line transect (ind/km) to a density per area (ind/km\2\), BP used the 
ESW of 1.15 km for bowheads, calculated from 2008-2012 aerial survey 
data flown with the Commander aircraft (M. Ferguson, NMML, pers. comm., 
30 Oct 2013).

[[Page 21541]]



 Table 6--Summary of Bowhead Sighting and Effort Data From the 2012 and 2013 ASAMM Aerial Surveys Flown in July
                                         and August in the Beaufort Sea
----------------------------------------------------------------------------------------------------------------
                                                   Effort  (ind/
                      Year                              km)           NR. ind         Ind/km         Ind/km\2\
----------------------------------------------------------------------------------------------------------------
2012............................................            1493               5          0.0033          0.0015
2013............................................            3973              88          0.0221          0.0096
Average.........................................  ..............  ..............  ..............          0.0055
Maximum.........................................  ..............  ..............  ..............          0.0096
Minimum.........................................  ..............  ..............  ..............          0.0015
----------------------------------------------------------------------------------------------------------------

3. Other Whale Species
    No densities have been estimated for gray whales and for whale 
species that are rare or extralimital to the Beaufort Sea (killer whale 
and harbor porpoise) because sightings of these animals have been very 
infrequent. Gray whales may be encountered in small numbers throughout 
the summer and fall, especially in the nearshore areas. Small numbers 
of harbor porpoises may be encountered as well. During an aerial survey 
offshore of Oliktok Point in 2008, approximately 40 mi (65 km) west of 
the proposed survey area, two harbor porpoises were sighted offshore of 
the barrier islands, one on 25 August and the other on 10 September 
(Hauser et al., 2008). For the purpose of this IHA request, small 
numbers have been included in the requested ``take'' authorization to 
cover incidental occurrences of any of these species during the 
proposed survey.
4. Seal Density Estimates
    Ice seals of the Beaufort Sea are mostly associated with sea ice, 
and most census methods count seals when they are hauled out on the 
ice. To account for the proportion of animals present but not hauled 
out (availability bias) or seals present on the ice but missed 
(detection bias), a correction factor should be applied to the ``raw'' 
counts. This correction factor is dependent on the behavior of each 
species. To estimate what proportion of ringed seals were generally 
visible resting on the sea ice, radio tags were placed on seals during 
spring 1999-2003 (Kelly et al., 2006). The probability that seals were 
visible, derived from the satellite data, was applied to seal abundance 
data from past aerial surveys and indicated that the proportion of 
seals visible varied from less than 0.4 to more than 0.75 between 
survey years. The environmental factors that are important in 
explaining the availability of seals to be counted were found to be 
time of day, date, wind speed, air temperature, and days from snow melt 
(Kelly et al., 2006). Besides the uncertainty in the correction factor, 
using counts of basking seals from spring surveys to predict seal 
abundance in the open-water period is further complicated by the fact 
that seal movements differ substantially between these two seasons. 
Data from nine ringed seals that were tracked from one subnivean period 
(early winter through mid-May or early June) to the next showed that 
ringed seals covered large distances during the open-water foraging 
period (Kelly et al., 2010b). Ringed seals tagged in 2011 close to 
Barrow also show long distances traveled during the open-water season 
(Herreman et al., 2012).
    To estimate densities for ringed, bearded, and spotted seals, BP 
used data collected during four shallow water OBC seismic surveys in 
the Beaufort Sea (Harris et al., 2001; Aerts et al., 2008; Hauser et 
al., 2008; HDR, 2012). Habitat and survey specifics are very similar to 
the proposed survey; therefore, these data were considered to be more 
representative than basking seal densities from spring aerial survey 
data (e.g., Moulton et al., 2002; Frost et al., 2002, 2004). NMFS 
agreed that these data are likely more representative and appropriate 
for use. However, since these data were not collected during surveys 
designed to determine abundance, NMFS used the maximum estimates for 
the proposed number of takes in this proposed IHA.
    Because survey effort in kilometers was only reported for one of 
the surveys, BP used sighting rate (ind/h) for calculating potential 
seal exposures. No distinction is made in seal density between summer 
and autumn season. Also, no correction factors have been applied to the 
reported seal sighting rates.
    Seal species ratios: During the 1996 OBC survey, 92% of all seal 
species identified were ringed seals, 7% bearded seals and 1% spotted 
seals (Harris et al., 2001). This 1996 survey occurred in two habitats, 
one about 19 mi east of Prudhoe Bay near the McClure Islands, mainly 
inshore of the barrier islands in water depths of 10 to 26 ft and the 
other 6 to 30 mi northwest of Prudhoe Bay, about 0 to 8 mile offshore 
of the barrier islands in water depths of 10 to 56 ft (Harris et al., 
2001). In 2008, two OBC seismic surveys occurred in the Beaufort Sea, 
one in Foggy Island Bay, about 15 mi SE of Prudhoe Bay (Aerts et al., 
2008), and the other at Oliktok Point, > 30 mi west of Prudhoe Bay 
(Hauser et al., 2008). In 2012, an OBC seismic was done in Simpson 
Lagoon, bordering the area surveyed in 2008 at Oliktok Point (HDR, 
2012). Based on the number of identified individuals the ratio ringed, 
bearded, and spotted seal was 75%, 8%, and 17%, respectively in Foggy 
Island Bay (Aerts et al., 2008), 22%, 39%, and 39%, respectively at 
Oliktok Point (Hauser et al., 2008), and 62%, 15%, and 23%, 
respectively in Simpson Lagoon (HDR, 2012). Because it is often 
difficult to identify seals to species, a large proportion of seal 
sightings were unidentified in all four OBC surveys described here. The 
total seal sighting rate was therefore used to calculate densities for 
each species, using the average ratio over all four surveys for ringed, 
bearded, and spotted seals, i.e., 63% ringed, 17% bearded, and 20% 
spotted seals.
    Seal sighting rates: During the 1996 OBC survey (Harris et al., 
2001) the sighting rate for all seals during periods when airguns were 
not operating was 0.63 ind/h. The sighting rate during non-seismic 
periods was 0.046 ind/h for the survey in Foggy Island Bay, just east 
of Prudhoe Bay (Aerts et al., 2008). The OBC survey that took place at 
Oliktok Point recorded 0.0674 ind/h when airguns were not operating 
(Hauser et al., 2008), and the maximum sighting rate during the Simpson 
Lagoon OBC seismic survey was 0.030 ind/h (HDR, 2012).
    The average seal sighting rate, based on these four surveys, was 
0.193 ind/h. The maximum was 0.63 ind/h and the minimum 0.03 ind/h. 
Using the proportion of ringed, bearded, and spotted seals as mentioned 
above, BP estimated the average and maximum sighting rates (ind/h) for 
each of the three seal species (Table 6 in the application and Table 7 
here).

[[Page 21542]]



   Table 7--Estimated Summer Densities of Whales and Sighting Rates of
  Seals (Average and Maximum) for the Proposed Foggy Island Bay Survey.
  Densities Are Provided in Number of Individuals Per Square Kilometer
  (ind/km\2\), and Sighting Rates Are in Number of Individuals per Hour
 (ind/h). No Densities or Sighting Rates Were Estimated for Extralimital
                                 Species
------------------------------------------------------------------------
                                                       Summer densities
                                                          (ind/km\2\)
                       Species                       -------------------
                                                       Average   Maximum
------------------------------------------------------------------------
Bowhead whale.......................................    0.0015    0.0055
Beluga whale........................................    0.0028    0.0105
------------------------------------------------------------------------


 
                                                        Summer sighting
                                                         rates (ind/h)
                                                     -------------------
                                                       Average   Maximum
------------------------------------------------------------------------
Ringed seal.........................................     0.122     0.397
Bearded seal........................................     0.033     0.107
Spotted seal........................................     0.039     0.126
------------------------------------------------------------------------

5. Marine Mammal Density Summary
    For the purpose of calculating the potential number of beluga and 
bowhead whale exposures to received sound levels of >=160 dB re 1 
[mu]Pa, BP used the minimum density from Tables 5 and 6 in this 
document as the average density. The reason for this decision is that 
the 2012 data only covered block 1 and were considered more 
representative. To derive a maximum estimated number of exposures, BP 
used the average densities from Tables 5 and 6 in this document. BP 
considered this approach reasonable because the 2013 beluga and bowhead 
whale sighting data included areas outside the zone of influence of the 
proposed project. For example, in 2013, only 3 of the 89 beluga 
sightings were seen in block 1. Table 7 in this document summarizes the 
densities used in the calculation of potential number of exposures.

Level A and Level B Harassment Zone Distances

    For the proposed 2014 shallow geohazard survey, BP used existing 
sound source verification (SSV) measurements to establish distances to 
received sound pressure levels (SPLs). Airgun arrays consist of a 
cluster of independent sources. Because of this, and many other 
factors, sounds generated by these arrays therefore do not propagate 
evenly in all directions. BP included both broadside and endfire 
measurements of the array in calculating distances to the various 
received sound levels. Broadside and endfire measurements are not 
applicable to mitigation gun measurements.
    Seven SSV measurements exist of 20-400 in\3\ airgun arrays in the 
shallow water environment of the Beaufort Sea that were considered to 
be representative of the proposed 30 in\3\ airgun arrays. These 
measurements were from 2008 (n = 4), 2011 (n = 1) and 2012 (n = 2), all 
in water depths less than about 50 ft. For the 5 in\3\ mitigation gun, 
measured distances of a 10 in\3\ mitigation gun from four shallow 
hazard SSV surveys in the Beaufort Sea were used: One in 2007, two in 
2008, and one in 2011. Table 7A in BP's application shows average, 
maximum, and minimum measured distances to each of the four received 
SPL rms levels for 20-40 in\3\ arrays and 10 in\3\ single gun. The 
mitigation radii of the proposed 30 in\3\ airgun arrays and 5 in\3\ gun 
were derived from the average distance of the 20-40 in\3\ and the 10 
in\3\ SSV measurements, respectively (see Table 8 in BP's application). 
Distances to sound pressure levels of 190, 180, and 160 dB re 1 [mu]Pa, 
generated by the proposed geophysical equipment is much lower than for 
airguns (see Table 7B in BP's application). The operating frequency of 
the sidescan sonar is within hearing range of toothed whales only, with 
a distance of 50 m to 180 dB re 1 [mu]Pa (rms) and 230 m to 160 dB re 1 
[mu]Pa (rms) (Warner & McCrodan, 2011). Sounds generated by the 
subbottom profiler are within the hearing range of all marine mammal 
species occurring in the area but do not produce sounds strong enough 
to reach sound pressure levels of 190 or 180 dB re 1 [mu]Pa (rms). The 
distance to 160 dB re 1 [mu]Pa (rms) is estimated at 30 m (Warner & 
McCrodan, 2011). BP considered the distances derived from the existing 
airgun arrays as summarized in Table 7A in BP's application as 
representative for the proposed 30 in\3\ arrays. NMFS concurs with this 
approach.
    Table 8 in this document presents the radii used to estimate take 
(160 dB isopleth) and to implement mitigation measures (180 dB and 190 
dB isopleths) from the full airgun array and the 5 in\3\ mitigation 
gun. However, take is only estimated using the larger radius of the 
full airgun array.

 Table 8--Distances (in Meters) To Be Used For Estimating Take by Level B Harassment and for Mitigation Purposes
                         During the Proposed 2014 North Prudhoe Bay 2014 Seismic Survey
----------------------------------------------------------------------------------------------------------------
   Airgun discharge volume (in\3\)      190 dB re 1 [micro]Pa    180 dB re 1 [micro]Pa    160 dB re 1 [micro]Pa
----------------------------------------------------------------------------------------------------------------
30 in\3\.............................                       70                      200                    1,600
5 in\3\..............................                       20                       50                      600
----------------------------------------------------------------------------------------------------------------

Numbers of Marine Mammals Potentially Taken by Harassment

    The potential number of marine mammals that might be exposed to the 
160 dB re 1 [micro]Pa (rms) SPL was calculated differently for 
cetaceans and pinnipeds, as described in Section 6.3 of BP's 
application and next here. BP did not calculate take from the subbottom 
profiler or from the sidescan sonar for toothed whales. Based on the 
distance to the 160 dB re 1 [micro]Pa (rms) isopleths for these sources 
and the fact that NMFS proposes to authorize the maximum estimated 
exposure estimate, the extremely minimal number of exposures that would 
result from use of these sources is already accounted for in the airgun 
exposure estimates.
1. Number of Cetaceans Potentially Taken by Harassment
    The potential number of bowhead and beluga whales that might be 
exposed to the 160 dB re 1 [mu]Pa (rms) sound pressure level was 
calculated by multiplying:
     The expected bowhead and beluga density as provided in 
Tables 5 and 6 in this document (Tables 4 and 5 in BP's application);
     The anticipated area around each source vessel that is 
ensonified by the 160 dB re 1 [mu]Pa (rms) sound pressure level; and
     The estimated number of 24-hr days that the source vessels 
are operating.
    The area expected to be ensonified by the 30 in\3\ array was 
determined based on the maximum distance to the 160 dB re 1 [mu]Pa 
(rms) SPL as determined from the maximum 20-40 in\3\ array measurements 
(Table 7A in BP's application), which is 1.6 km. Based on

[[Page 21543]]

a radius of 1.6 km, the 160 dB isopleth used in the exposure 
calculations was 8 km\2\.
    The estimated number of 24-hr days of airgun operations is 7.5 days 
(180 hours), not including downtime. Downtime is related to weather, 
equipment maintenance, mitigation implementation, and other 
circumstances.
    Average and maximum estimates of the number of bowhead and beluga 
whales potentially exposed to sound pressure levels of 160 dB re 
1[mu]Pa (rms) or more are summarized in Table 9 in BP's application. 
Species such as gray whale, killer whale, and harbor porpoise are not 
expected to be encountered but might be present in very low numbers; 
the maximum expected number of exposures for these species provided in 
Table 9 of BP's application is based on the likelihood of incidental 
occurrences.
    The average and maximum number of bowhead whales potentially 
exposed to sound levels of 160 dB re 1[mu]Pa (rms) or more is estimated 
at 0 and 1, respectively. BP requested to take three bowheads to 
account for chance encounters. The average and maximum number of 
potential beluga exposures to 160 dB is 0 and 1, respectively. Belugas 
are known to show aggregate behavior and can occur in large numbers in 
nearshore zones, as evidenced by the sighting at Endicott in August 
2013. Therefore, for the unlikely event that a group of belugas appears 
within the 160 dB isopleth during the proposed seismic survey, BP added 
a number of 75 to the requested authorization. Chance encounters with 
small numbers of other whale species are possible.
    These estimated exposures do not take into account the proposed 
mitigation measures, such as PSOs watching for animals, shutdowns or 
power downs of the airguns when marine mammals are seen within defined 
ranges, and ramp-up of airguns.
2. Number of Pinnipeds Potentially Taken by Harassment
    The estimated number of seals that might be exposed to pulsed 
sounds of 160 dB re 1 [mu]Pa (rms) was calculated by multiplying:
     The expected species specific sighting rate as provided in 
Table 7 in this document (also in Table 6 in BP's application); and
     The total number of hours that each source vessel will be 
operating during the data acquisition period.
    The estimated number of hours that airguns will be operating is 180 
hours (7.5 days of 24 hour operations). The resulting average and 
maximum number of ringed, bearded, and spotted seal exposures based on 
180 hours of airgun operations are summarized in Table 9 of BP's 
application. BP assumed that all seal sightings would occur within the 
160 dB isopleth. These estimated exposures do not take into account the 
proposed mitigation measures, such as PSOs watching for animals, 
shutdowns or power downs of the airguns when marine mammals are seen 
within defined ranges, and ramp-up of airguns.

Estimated Take by Harassment Summary

    Table 9 here outlines the density estimates used to estimate Level 
B takes, the proposed Level B harassment take levels, the abundance of 
each species in the Beaufort Sea, the percentage of each species or 
stock estimated to be taken, and current population trends. As 
explained earlier in this document, NMFS used the maximum density 
estimates or sighting rates and proposes to authorize the maximum 
estimates of exposures. Additionally, as explained earlier, density 
estimates are not available for species that are uncommon in the 
proposed survey area.

   Table 9--Density Estimates or Species Sighting Rates, Proposed Level B Harassment Take Levels, Species or Stock Abundance, Percentage of Population
                                                     Proposed To Be Taken, and Species Trend Status
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                Density
                  Species                     (/    Sighting rate  Proposed Level     Abundance     Percentage of              Trend
                                                km\2\)         (ind/hr)         B take                        population
--------------------------------------------------------------------------------------------------------------------------------------------------------
Beluga whale..............................          0.0105  ..............              75          39,258            0.19  No reliable information.
Killer whale..............................              NA  ..............               1             552            0.18  Stable.
Harbor porpoise...........................              NA  ..............               1          48,215           >0.01  No reliable information.
Bowhead whale.............................          0.0055  ..............               3          16,892            0.02  Increasing.
Gray whale................................              NA  ..............               1          19,126            0.01  Increasing.
Bearded seal..............................  ..............           0.107              19         155,000            0.01  No reliable information.
Ringed seal...............................  ..............           0.397              71         300,000            0.02  No reliable information.
Spotted seal..............................  ..............           0.126              23         141,479            0.02  No reliable information.
Ribbon seal...............................  ..............              NA               1          49,000           >0.01  No reliable information.
--------------------------------------------------------------------------------------------------------------------------------------------------------

Analysis and Preliminary Determinations

Negligible Impact

    Negligible impact is ``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'' (50 CFR 216.103). A 
negligible impact finding is based on the lack of likely adverse 
effects on annual rates of recruitment or survival (i.e., population-
level effects). An estimate of the number of Level B harassment takes, 
alone, is not enough information on which to base an impact 
determination. In addition to considering estimates of the number of 
marine mammals that might be ``taken'' through behavioral harassment, 
NMFS must consider other factors, such as the likely nature of any 
responses (their intensity, duration, etc.), the context of any 
responses (critical reproductive time or location, migration, etc.), as 
well as the number and nature of estimated Level A harassment takes, 
the number of estimated mortalities, effects on habitat, and the status 
of the species.
    No injuries or mortalities are anticipated to occur as a result of 
BP's proposed shallow geohazard survey, and none are proposed to be 
authorized. Additionally, animals in the area are not expected to incur 
hearing impairment (i.e., TTS or PTS) or non-auditory physiological 
effects. The number of takes that are anticipated and authorized are 
expected to be limited to short-term Level B behavioral harassment. 
While the airguns will be operated continuously for about 7.5 days, the 
project time frame will occur when cetacean species are typically not 
found in the project area or are found only in low numbers. While 
pinnipeds are likely to be found in the proposed project area more 
frequently, their distribution is dispersed enough that they likely 
will not be in the Level B harassment zone continuously. As mentioned 
previously in this document, pinnipeds appear to be more tolerant of 
anthropogenic sound than mystiectes.

[[Page 21544]]

The use of sidescan sonar, multibeam echosounder, and subbottom 
profiler continuously for 7.5 days will not negatively impact marine 
mammals as the majority of these instruments are operated outside of 
the hearing frequencies of marine mammals.
    The Alaskan Beaufort Sea is part of the main migration route of the 
Western Arctic stock of bowhead whales. However, the seismic survey has 
been planned to occur when the majority of the population is found in 
the Canadian Beaufort Sea. Operation of airguns and other sound sources 
will cease by midnight on August 25 before the main fall migration 
begins and well before cow/calf pairs begin migrating through the area. 
Additionally, several locations within the Beaufort Sea serve as 
feeding grounds for bowhead whales. However, as mentioned earlier in 
this document, the primary feeding grounds are not found in Foggy 
Island Bay. The majority of bowhead whales feed in the Alaskan Beaufort 
Sea during the fall migration period, which will occur after the 
cessation of the survey.
    Belugas that migrate through the U.S. Beaufort Sea typically do so 
farther offshore (more than 37 mi [60 km]) and in deeper waters (more 
than 656 ft [200 m]) than where the proposed survey activities would 
occur. Gray whales are rarely sighted this far east in the U.S. 
Beaufort Sea. Additionally, there are no known feeding grounds for gray 
whales in the Foggy Island Bay area. The most northern feeding sites 
known for this species are located in the Chukchi Sea near Hanna Shoal 
and Point Barrow. The other cetacean species for which take is proposed 
are uncommon in Foggy Island Bay, and no known feeding or calving 
grounds occur in Foggy Island Bay for these species. Based on these 
factors, exposures of cetaceans to anthropogenic sounds are not 
expected to last for prolonged periods (i.e., several days) since they 
are not known to remain in the area for extended periods of time in 
July and August. Also, the shallow water location of the survey makes 
it unlikely that cetaceans would remain in the area for prolonged 
periods. Based on all of this information, the proposed project is not 
anticipated to affect annual rates of recruitment or survival for 
cetaceans in the area.
    Ringed seals breed and pup in the Alaskan Beaufort Sea; however, 
the proposed survey will occur outside of the breeding and pupping 
seasons. The Beaufort Sea does not provide suitable habitat for the 
other three ice seal species for breeding and pupping. Based on this 
information, the proposed project is not anticipated to affect annual 
rates of recruitment or survival for pinnipeds in the area.
    Of the nine marine mammal species for which take is authorized, one 
is listed as endangered under the ESA--the bowhead whale--and two are 
listed as threatened--ringed and bearded seals. Schweder et al. (2009) 
estimated the yearly growth rate to be 3.2% (95% CI = 0.5-4.8%) between 
1984 and 2003 using a sight-resight analysis of aerial photographs. 
There are currently no reliable data on trends of the ringed and 
bearded seal stocks in Alaska. The ribbon seal is listed as a species 
of concern under the ESA. Certain stocks or populations of gray, 
killer, and beluga whales and spotted seals are listed as endangered or 
are proposed for listing under the ESA; however, none of those stocks 
or populations occur in the activity area. There is currently no 
established critical habitat in the project area for any of these nine 
species.
    Based on the analysis contained herein of the likely effects of the 
specified activity on marine mammals and their habitat, and taking into 
consideration the implementation of the proposed monitoring and 
mitigation measures, NMFS preliminarily finds that the total marine 
mammal take from BP's proposed shallow geohazard survey in Foggy Island 
Bay, Beaufort Sea, Alaska, will have a negligible impact on the 
affected marine mammal species or stocks.

Small Numbers

    The requested takes proposed to be authorized represent less than 
1% of all populations or stocks (see Table 9 in this document). These 
take estimates represent the percentage of each species or stock that 
could be taken by Level B behavioral harassment if each animal is taken 
only once. The numbers of marine mammals taken are small relative to 
the affected species or stock sizes. In addition, the mitigation and 
monitoring measures (described previously in this document) proposed 
for inclusion in the IHA (if issued) are expected to reduce even 
further any potential disturbance to marine mammals. NMFS preliminarily 
finds that small numbers of marine mammals will be taken relative to 
the populations of the affected species or stocks. Impact on 
Availability of Affected Species or Stock for Taking for Subsistence 
Uses

Relevant Subsistence Uses

    The disturbance and potential displacement of marine mammals by 
sounds from the proposed survey are the principal concerns related to 
subsistence use of the area. Subsistence remains the basis for Alaska 
Native culture and community. Marine mammals are legally hunted in 
Alaskan waters by coastal Alaska Natives. In rural Alaska, subsistence 
activities are often central to many aspects of human existence, 
including patterns of family life, artistic expression, and community 
religious and celebratory activities. Additionally, the animals taken 
for subsistence provide a significant portion of the food that will 
last the community throughout the year. The main species that are 
hunted include bowhead and beluga whales, ringed, spotted, and bearded 
seals, walruses, and polar bears. (As mentioned previously in this 
document, both the walrus and the polar bear are under the USFWS' 
jurisdiction.) The importance of each of these species varies among the 
communities and is largely based on availability.
    Residents of the village of Nuiqsut are the primary subsistence 
users in the project area. The communities of Barrow and Kaktovik also 
harvest resources that pass through the area of interest but do not 
hunt in or near the Foggy Island Bay area. Subsistence hunters from all 
three communities conduct an annual hunt for autumn-migrating bowhead 
whales. Barrow also conducts a bowhead hunt in spring. Residents of all 
three communities hunt seals. Other subsistence activities include 
fishing, waterfowl and seaduck harvests, and hunting for walrus, beluga 
whales, polar bears, caribou, and moose.
    Nuiqsut is the community closest to the seismic survey area 
(approximately 73 mi [117.5 km] southwest). Nuiqsut hunters harvest 
bowhead whales only during the fall whaling season (Long, 1996). In 
recent years, Nuiqsut whalers have typically landed three or four 
whales per year. Nuiqsut whalers concentrate their efforts on areas 
north and east of Cross Island, generally in water depths greater than 
66 ft (20 m; Galginaitis, 2009). Cross Island is the principal base for 
Nuiqsut whalers while they are hunting bowheads (Long, 1996). Cross 
Island is located approximately 10 mi (16 km) from the closest boundary 
of the survey area.
    Kaktovik whalers search for whales east, north, and occasionally 
west of Kaktovik. Kaktovik is located approximately 91 mi (146.5 km) 
east of Foggy Island Bay. The western most reported harvest location 
was about 13 mi (21 km) west of Kaktovik, near 70[deg]10' N., 
144[deg]11' W. (Kaleak, 1996). That site is about 80 mi (129 km) east 
of the proposed survey area.
    Barrow whalers search for whales much farther from the Foggy Island 
Bay area--about 200+ mi (322+ km) to the west. Barrow hunters have 
expressed

[[Page 21545]]

concerns about ``downstream'' effects to bowhead whales during the 
westward fall migration; however, BP will cease airgun operations prior 
to the start of the fall migration.
    Beluga whales are not a prevailing subsistence resource in the 
communities of Kaktovik and Nuiqsut. Kaktovik hunters may harvest one 
beluga whale in conjunction with the bowhead hunt; however, it appears 
that most households obtain beluga through exchanges with other 
communities. Although Nuiqsut hunters have not hunted belugas for many 
years while on Cross Island for the fall hunt, this does not mean that 
they may not return to this practice in the future. Data presented by 
Braund and Kruse (2009) indicate that only 1% of Barrow's total harvest 
between 1962 and 1982 was of beluga whales and that it did not account 
for any of the harvested animals between 1987 and 1989.
    Ringed seals are available to subsistence users in the Beaufort Sea 
year-round, but they are primarily hunted in the winter or spring due 
to the rich availability of other mammals in the summer. Bearded seals 
are primarily hunted during July in the Beaufort Sea; however, in 2007, 
bearded seals were harvested in the months of August and September at 
the mouth of the Colville River Delta, which is approximately 50+ mi 
(80+ km) from the proposed survey area. However, this sealing area can 
reach as far east as Pingok Island, which is approximately 20 mi (32 
km) west of the survey area. An annual bearded seal harvest occurs in 
the vicinity of Thetis Island (which is a considerable distance from 
Foggy Island Bay) in July through August. Approximately 20 bearded 
seals are harvested annually through this hunt. Spotted seals are 
harvested by some of the villages in the summer months. Nuiqsut hunters 
typically hunt spotted seals in the nearshore waters off the Colville 
River Delta. The majority of the more established seal hunts that occur 
in the Beaufort Sea, such as the Colville delta area hunts, are located 
a significant distance (in some instances 50 mi [80 km] or more) from 
the project area.

Potential Impacts to Subsistence Uses

    NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 
as: ``. . . an impact resulting from the specified activity: (1) That 
is likely to reduce the availability of the species to a level 
insufficient for a harvest to meet subsistence needs by: (i) Causing 
the marine mammals to abandon or avoid hunting areas; (ii) Directly 
displacing subsistence users; or (iii) Placing physical barriers 
between the marine mammals and the subsistence hunters; and (2) That 
cannot be sufficiently mitigated by other measures to increase the 
availability of marine mammals to allow subsistence needs to be met.''
    Noise and general activity during BP's proposed shallow geohazard 
survey have the potential to impact marine mammals hunted by Native 
Alaskan. In the case of cetaceans, the most common reaction to 
anthropogenic sounds (as noted previously) is avoidance of the 
ensonified area. In the case of bowhead whales, this often means that 
the animals divert from their normal migratory path by several 
kilometers. Helicopter activity, although not really anticipated, also 
has the potential to disturb cetaceans and pinnipeds by causing them to 
vacate the area. Additionally, general vessel presence in the vicinity 
of traditional hunting areas could negatively impact a hunt. Native 
knowledge indicates that bowhead whales become increasingly 
``skittish'' in the presence of seismic noise. Whales are more wary 
around the hunters and tend to expose a much smaller portion of their 
back when surfacing (which makes harvesting more difficult). 
Additionally, natives report that bowheads exhibit angry behaviors in 
the presence of seismic, such as tail-slapping, which translate to 
danger for nearby subsistence harvesters.

Plan of Cooperation or Measures To Minimize Impacts to Subsistence 
Hunts

    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a Plan of 
Cooperation or information that identifies what measures have been 
taken and/or will be taken to minimize adverse effects on the 
availability of marine mammals for subsistence purposes. BP has begun 
discussions with the Alaska Eskimo Whaling Commission (AEWC) to develop 
a Conflict Avoidance Agreement (CAA) intended to minimize potential 
interference with bowhead subsistence hunting. BP also attended and 
participated in meetings with the AEWC on December 13, 2013, and will 
attend future meetings to be scheduled in 2014. The CAA, when executed, 
will describe measures to minimize any adverse effects on the 
availability of bowhead whales for subsistence uses.
    The North Slope Borough Department of Wildlife Management (NSB-DWM) 
will be consulted, and BP plans to present the project to the NSB 
Planning Commission in 2014. BP will hold meetings in the community of 
Nuiqsut to present the proposed project, address questions and concerns 
from community members, and provide them with contact information of 
project management to which they can direct concerns during the survey. 
During the NMFS Open-Water Meeting in Anchorage in 2013, BP presented 
their proposed projects to various stakeholders that were present 
during this meeting.
    BP will continue to engage with the affected subsistence 
communities regarding its Beaufort Sea activities. As in previous 
years, BP will meet formally and/or informally with several stakeholder 
entities: The NSB Planning Department, NSB-DWM, NMFS, AEWC, Inupiat 
Community of the Arctic Slope, Inupiat History Language and Culture 
Center, USFWS, Nanuq and Walrus Commissions, and Alaska Department of 
Fish & Game.
    Project information was provided to and input on subsistence 
obtained from the AEWC and Nanuq Commission at the following meetings:
     AEWC, October 17, 2013; and
     Nanuq Commission, October 17, 2013.
    Additional meetings with relevant stakeholders will be scheduled 
and a record of attendance and topics discussed will be maintained and 
submitted to NMFS.
    BP proposes to implement several mitigation measures to reduce 
impacts on the availability of marine mammals for subsistence hunts in 
the Beaufort Sea. Many of these measures were developed from the 2013 
CAA and previous NSB Development Permits. In addition to the measures 
listed next, BP will cease all airgun operations by midnight on August 
25 to allow time for the Beaufort Sea communities to prepare for their 
fall bowhead whale hunts prior to the beginning of the fall westward 
migration through the Beaufort Sea. Some of the measures mentioned next 
have been mentioned previously in this document:
     PSOs on board vessels are tasked with looking out for 
whales and other marine mammals in the vicinity of the vessel to assist 
the vessel captain in avoiding harm to whales and other marine 
mammals.;
     Vessels and aircraft will avoid areas where species that 
are sensitive to noise or vessel movements are concentrated;
     Communications and conflict resolution are detailed in the 
CAA. BP will participate in the Communications Center that is operated 
annually during the bowhead subsistence hunt;
     Communications with the village of Nuiqsut to discuss 
community questions or concerns including all subsistence hunting 
activities. Pre-project meeting(s) with Nuiqsut

[[Page 21546]]

representatives will be held at agreed times with groups in the 
community of Nuiqsut. If additional meetings are requested, they will 
be set up in a similar manner;
     Contact information for BP will be provided to community 
members and distributed in a manner agreed at the community meeting;
     BP has contracted with a liaison from Nuiqsut who will 
help coordinate meetings and serve as an additional contact for local 
residents during planning and operations; and
     Inupiat Communicators will be employed and work on seismic 
source vessels. They will also serve as PSOs.

Unmitigable Adverse Impact Analysis and Preliminary Determination

    BP has adopted a spatial and temporal strategy for its Foggy Island 
Bay survey that should minimize impacts to subsistence hunters. First, 
BP's activities will not commence until after the spring hunts have 
occurred. Second, BP will cease all airgun operations by midnight on 
August 25 prior to the start of the bowhead whale fall westward 
migration and any fall subsistence hunts by Beaufort Sea communities. 
Foggy Island Bay is not commonly used for subsistence hunts. Although 
some seal hunting co-occurs temporally with BP's proposed survey, the 
locations do not overlap. BP's presence will not place physical 
barriers between the sealers and the seals. Additionally, BP will work 
closely with the closest affected communities and support 
Communications Centers and employ local Inupiat Communicators. Based on 
the description of the specified activity, the measures described to 
minimize adverse effects on the availability of marine mammals for 
subsistence purposes, and the proposed mitigation and monitoring 
measures, NMFS has preliminarily determined that there will not be an 
unmitigable adverse impact on subsistence uses from BP's proposed 
activities.

Endangered Species Act (ESA)

    Within the project area, the bowhead whale is listed as endangered 
and the ringed and bearded seals are listed as threatened under the 
ESA. NMFS' Permits and Conservation Division has initiated consultation 
with staff in NMFS' Alaska Region Protected Resources Division under 
section 7 of the ESA on the issuance of an IHA to BP under section 
101(a)(5)(D) of the MMPA for this activity. Consultation will be 
concluded prior to a determination on the issuance of an IHA.

National Environmental Policy Act (NEPA)

    NMFS is currently conducting an analysis, pursuant to NEPA, to 
determine whether this proposed IHA may have a significant effect on 
the human environment. This analysis will be completed prior to the 
issuance or denial of this proposed IHA.

Proposed Authorization

    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to BP for conducting a shallow geohazard survey in the 
Foggy Island Bay area of the Beaufort Sea, Alaska, during the 2014 
open-water season, provided the previously mentioned mitigation, 
monitoring, and reporting requirements are incorporated. The proposed 
IHA language is provided next.
    This section contains a draft of the IHA itself. The wording 
contained in this section is proposed for inclusion in the IHA (if 
issued).
    1. This IHA is valid from July 1, 2014, through September 30, 2014.
    2. This IHA is valid only for activities associated with open-water 
shallow geohazard surveys and related activities in the Beaufort Sea. 
The specific areas where BP's surveys will be conducted are within the 
Foggy Island Bay Area, Beaufort Sea, Alaska, as shown in Figure 1 of 
BP's IHA application.
    3. Species Authorized and Level of Take:
    a. The incidental taking of marine mammals, by Level B harassment 
only, is limited to the following species in the waters of the Beaufort 
Sea:
    i. Odontocetes: 75 Beluga whales; 1 killer whale; and 1 harbor 
porpoise.
    ii. Mysticetes: 3 Bowhead whales and 1 gray whale.
    iii. Pinnipeds: 71 Ringed seals; 19 bearded seals; 23 spotted 
seals; and 1 ribbon seal.
    iv. If any marine mammal species not listed in conditions 3(a)(i) 
through (iii) are encountered during seismic survey operations and are 
likely to be exposed to sound pressure levels (SPLs) greater than or 
equal to 160 dB re 1 [micro]Pa (rms) for impulse sources, then the 
Holder of this IHA must shut-down the sound source to avoid take.
    b. The taking by injury (Level A harassment) serious injury, or 
death of any of the species listed in condition 3(a) or the taking of 
any kind of any other species of marine mammal is prohibited and may 
result in the modification, suspension or revocation of this IHA.
    4. The authorization for taking by harassment is limited to the 
following acoustic sources (or sources with comparable frequency and 
intensity) and from the following activities:
    a. 30 in\3\ airgun arrays;
    b. 10 in\3\ and/or 5 in\3\ mitigation airguns; and
    c. Vessel activities related to the OBS seismic survey.
    5. The taking of any marine mammal in a manner prohibited under 
this Authorization must be reported within 24 hours of the taking to 
the Alaska Regional Administrator or his designee and the Chief of the 
Permits and Conservation Division, Office of Protected Resources, NMFS, 
or her designee.
    6. The holder of this Authorization must notify the Chief of the 
Permits and Conservation Division, Office of Protected Resources, at 
least 48 hours prior to the start of collecting seismic data (unless 
constrained by the date of issuance of this IHA in which case 
notification shall be made as soon as possible).
    7. Mitigation Requirements: The Holder of this Authorization is 
required to implement the following mitigation requirements when 
conducting the specified activities to achieve the least practicable 
impact on affected marine mammal species or stocks:
    a. General Vessel and Aircraft Mitigation
    i. Avoid concentrations or groups of whales by all vessels under 
the direction of BP. Operators of support vessels should, at all times, 
conduct their activities at the maximum distance possible from such 
concentrations of whales.
    ii. The vessel shall be operated at speeds necessary to ensure no 
physical contact with whales occurs. If the vessel approaches within 
1.6 km (1 mi) of observed whales, except when providing emergency 
assistance to whalers or in other emergency situations, the vessel 
operator will take reasonable precautions to avoid potential 
interaction with the whales by taking one or more of the following 
actions, as appropriate:
    A. Reducing vessel speed to less than 5 knots within 300 yards (900 
feet or 274 m) of the whale(s);
    B. Steering around the whale(s) if possible;
    C. Operating the vessel(s) in such a way as to avoid separating 
members of a group of whales from other members of the group;
    D. Operating the vessel(s) to avoid causing a whale to make 
multiple changes in direction;
    E. Checking the waters immediately adjacent to the vessel(s) to 
ensure that

[[Page 21547]]

no whales will be injured when the propellers are engaged; and
    F. Reducing vessel speed to less than 9 knots when weather 
conditions reduce visibility.
    iii. When weather conditions require, such as when visibility 
drops, adjust vessel speed accordingly to avoid the likelihood of 
injury to whales.
    iv. In the event that any aircraft (such as helicopters) are used 
to support the planned survey, the mitigation measures below would 
apply:
    A. Under no circumstances, other than an emergency, shall aircraft 
be operated at an altitude lower than 1,000 feet above sea level when 
within 0.3 mile (0.5 km) of groups of whales.
    B. Helicopters shall not hover or circle above or within 0.3 mile 
(0.5 km) of groups of whales.
    C. At all other times, aircraft should attempt not to fly below 
1,000 ft except during emergencies and take-offs and landings.
b. Seismic Airgun Mitigation
    i. Whenever a marine mammal is detected outside the exclusion zone 
radius and based on its position and motion relative to the ship track 
is likely to enter the exclusion radius, calculate and implement an 
alternative ship speed or track or de-energize the airgun array, as 
described in condition 7(b)(iv) below.
    ii. Exclusion Zones:
    A. Establish and monitor with trained PSOs an exclusion zone for 
cetaceans surrounding the airgun array on the source vessel where the 
received level would be 180 dB re 1 [micro]Pa rms. This radius is 
estimated to be 200 m from the seismic source for the 30 in\3\ airgun 
arrays and 50 m for a single 5 in\3\ airgun.
    B. Establish and monitor with trained PSOs an exclusion zone for 
pinnipeds surrounding the airgun array on the source vessel where the 
received level would be 190 dB re 1 [micro]Pa rms. This radius is 
estimated to be 70 m from the seismic source for the 30 in\3\ airgun 
arrays and 20 m for a single 5 in\3\ airgun.
    iii. Ramp-up:
    A. A ramp-up, following a cold start, can be applied if the 
exclusion zone has been free of marine mammals for a consecutive 30-
minute period. The entire exclusion zone must have been visible during 
these 30 minutes. If the entire exclusion zone is not visible, then 
ramp-up from a cold start cannot begin.
    B. Ramp-up procedures from a cold start shall be delayed if a 
marine mammal is sighted within the exclusion zone during the 30-minute 
period prior to the ramp up. The delay shall last until the marine 
mammal(s) has been observed to leave the exclusion zone or until the 
animal(s) is not sighted for at least 15 or 30 minutes. The 15 minutes 
applies to pinnipeds, while a 30 minute observation period applies to 
cetaceans.
    C. A ramp-up, following a shutdown, can be applied if the marine 
mammal(s) for which the shutdown occurred has been observed to leave 
the exclusion zone or until the animal(s) is not sighted for at least 
15 minutes (pinnipeds) or 30 minutes (cetaceans).
    D. If, for any reason, electrical power to the airgun array has 
been discontinued for a period of 10 minutes or more, ramp-up 
procedures shall be implemented. Only if the PSO watch has been 
suspended, a 30-minute clearance of the exclusion zone is required 
prior to commencing ramp-up. Discontinuation of airgun activity for 
less than 10 minutes does not require a ramp-up.
    E. The seismic operator and PSOs shall maintain records of the 
times when ramp-ups start and when the airgun arrays reach full power.
    F. The ramp-up will be conducted by doubling the number of 
operating airguns at 5-minute intervals, starting with the smallest gun 
in the array.
    iv. Power-down/Shutdown:
    A. The airgun array shall be immediately powered down (reduction in 
the number of operating airguns such that the radii of exclusion zones 
are decreased) whenever a marine mammal is sighted approaching close to 
or within the applicable exclusion zone of the full array, but is 
outside the applicable exclusion zone of the single mitigation airgun.
    B. If a marine mammal is already within the exclusion zone when 
first detected, the airguns shall be powered down immediately.
    C. Following a power-down, ramp-up to the full airgun array shall 
not resume until the marine mammal has cleared the exclusion zone. The 
animal will be considered to have cleared the exclusion zone if it is 
visually observed to have left the exclusion zone of the full array, or 
has not been seen within the zone for 15 minutes (pinnipeds) or 30 
minutes (cetaceans).
    D. If a marine mammal is sighted within or about to enter the 190 
or 180 dB (rms) applicable exclusion zone of the single mitigation 
airgun, the airgun array shall be shutdown immediately.
    E. Airgun activity after a complete shutdown shall not resume until 
the marine mammal has cleared the exclusion zone of the full array. The 
animal will be considered to have cleared the exclusion zone as 
described above under ramp-up procedures.
    v. Poor Visibility Conditions:
    A. If during foggy conditions, heavy snow or rain, or darkness, the 
full 180 dB exclusion zone is not visible, the airguns cannot commence 
a ramp-up procedure from a full shut-down.
    B. If one or more airguns have been operational before nightfall or 
before the onset of poor visibility conditions, they can remain 
operational throughout the night or poor visibility conditions. In this 
case ramp-up procedures can be initiated, even though the exclusion 
zone may not be visible, on the assumption that marine mammals will be 
alerted by the sounds from the single airgun and have moved away.
    C. The mitigation airgun will be operated at approximately one shot 
per minute and will not be operated for longer than three hours in 
duration during daylight hours and good visibility. In cases when the 
next start-up after the turn is expected to be during lowlight or low 
visibility, use of the mitigation airgun may be initiated 30 minutes 
before darkness or low visibility conditions occur and may be operated 
until the start of the next seismic acquisition line. The mitigation 
gun must still be operated at approximately one shot per minute.
c. Subsistence Mitigation
    i. Airgun and echosounder, sonar, and subbottom profiler operations 
must cease no later than midnight on August 25, 2014;
    ii. BP will participate in the Communications Center that is 
operated annually during the bowhead subsistence hunt; and
    iii. Inupiat communicators will work on the seismic vessels.
8. Monitoring
    a. The holder of this Authorization must designate biologically-
trained, on-site individuals (PSOs) to be onboard the source vessels, 
who are approved in advance by NMFS, to conduct the visual monitoring 
programs required under this Authorization and to record the effects of 
seismic surveys and the resulting sound on marine mammals.
    i. PSO teams shall consist of Inupiat observers and experienced 
field biologists. An experienced field crew leader will supervise the 
PSO team onboard the survey vessel. New observers shall be paired with 
experienced observers to avoid situations where lack of experience 
impairs the quality of observations.
    ii. Crew leaders and most other biologists serving as observers 
will be individuals with experience as observers during recent seismic 
or shallow hazards monitoring projects in

[[Page 21548]]

Alaska, the Canadian Beaufort, or other offshore areas in recent years.
    iii. PSOs shall complete a training session on marine mammal 
monitoring, to be conducted shortly before the anticipated start of the 
2014 open-water season. The training session(s) will be conducted by 
qualified marine mammalogists with extensive crew-leader experience 
during previous vessel-based monitoring programs. An observers' 
handbook, adapted for the specifics of the planned survey program will 
be reviewed as part of the training.
    iv. If there are Alaska Native PSOs, the PSO training that is 
conducted prior to the start of the survey activities shall be 
conducted with both Alaska Native PSOs and biologist PSOs being trained 
at the same time in the same room. There shall not be separate training 
courses for the different PSOs.
    v. Crew members should not be used as primary PSOs because they 
have other duties and generally do not have the same level of 
expertise, experience, or training as PSOs, but they could be stationed 
on the fantail of the vessel to observe the near field, especially the 
area around the airgun array and implement a power-down or shutdown if 
a marine mammal enters the exclusion zone).
    vi. If crew members are to be used as PSOs, they shall go through 
some basic training consistent with the functions they will be asked to 
perform. The best approach would be for crew members and PSOs to go 
through the same training together.
    vii. PSOs shall be trained using visual aids (e.g., videos, 
photos), to help them identify the species that they are likely to 
encounter in the conditions under which the animals will likely be 
seen.
    viii. BP shall train its PSOs to follow a scanning schedule that 
consistently distributes scanning effort according to the purpose and 
need for observations. For example, the schedule might call for 60% of 
scanning effort to be directed toward the near field and 40% at the far 
field. All PSOs should follow the same schedule to ensure consistency 
in their scanning efforts.
    ix. PSOs shall be trained in documenting the behaviors of marine 
mammals. PSOs should simply record the primary behavioral state (i.e., 
traveling, socializing, feeding, resting, approaching or moving away 
from vessels) and relative location of the observed marine mammals.
    b. To the extent possible, PSOs should be on duty for four (4) 
consecutive hours or less, although more than one four-hour shift per 
day is acceptable; however, an observer shall not be on duty for more 
than 12 hours in a 24-hour period.
    c. Monitoring is to be conducted by the PSOs onboard the active 
seismic vessels to ensure that no marine mammals enter the appropriate 
exclusion zone whenever the seismic acoustic sources are on and to 
record marine mammal activity as described in condition 8(f). Two PSOs 
will be present on the vessel. At least one PSO shall monitor for 
marine mammals at any time during daylight hours.
    d. At all times, the crew must be instructed to keep watch for 
marine mammals. If any are sighted, the bridge watch-stander must 
immediately notify the PSO(s) on-watch. If a marine mammal is within or 
closely approaching its designated exclusion zone, the seismic acoustic 
sources must be immediately powered down or shutdown (in accordance 
with condition 7(b)(iv)).
    e. Observations by the PSOs on marine mammal presence and activity 
will begin a minimum of 30 minutes prior to the estimated time that the 
seismic source is to be turned on and/or ramped-up.
    f. All marine mammal observations and any airgun power-down, shut-
down and ramp-up will be recorded in a standardized format. Data will 
be entered into a custom database. The accuracy of the data entry will 
be verified daily through QA/QC procedures. These procedures will allow 
initial summaries of data to be prepared during and shortly after the 
field program, and will facilitate transfer of the data to other 
programs for further processing and archiving.
    g. Monitoring shall consist of recording:
    i. The species, group size, age/size/sex categories (if 
determinable), the general behavioral activity, heading (if 
consistent), bearing and distance from seismic vessel, sighting cue, 
behavioral pace, and apparent reaction of all marine mammals seen near 
the seismic vessel and/or its airgun array (e.g., none, avoidance, 
approach, paralleling, etc);
    ii. The time, location, heading, speed, and activity of the vessel 
(shooting or not), along with sea state, visibility, cloud cover and 
sun glare at:
    A. Any time a marine mammal is sighted (including pinnipeds hauled 
out on barrier islands),
    B. At the start and end of each watch, and
    C. During a watch (whenever there is a change in one or more 
variable);
    iii. The identification of all vessels that are visible within 5 km 
of the seismic vessel whenever a marine mammal is sighted, and the time 
observed, bearing, distance, heading, speed and activity of the other 
vessel(s);
    iv. Any identifiable marine mammal behavioral response (sighting 
data should be collected in a manner that will not detract from the 
PSO's ability to detect marine mammals);
    v. Any adjustments made to operating procedures; and
    iv. Visibility during observation periods so that total estimates 
of take can be corrected accordingly.
    h. BP shall work with its observers to develop a means for 
recording data that does not reduce observation time significantly.
    i. PSOs shall use the best possible positions for observing (e.g., 
outside and as high on the vessel as possible), taking into account 
weather and other working conditions. PSOs shall carefully document 
visibility during observation periods so that total estimates of take 
can be corrected accordingly.
    j. PSOs shall scan systematically with the unaided eye and reticle 
binoculars, and other devices.
    k. PSOs shall attempt to maximize the time spent looking at the 
water and guarding the exclusion radii. They shall avoid the tendency 
to spend too much time evaluating animal behavior or entering data on 
forms, both of which detract from their primary purpose of monitoring 
the exclusion zone.
    l. Night-vision equipment (Generation 3 binocular image 
intensifiers, or equivalent units) shall be available for use during 
low light hours, and BP shall continue to research methods of detecting 
marine mammals during periods of low visibility.
    m. PSOs shall understand the importance of classifying marine 
mammals as ``unknown'' or ``unidentified'' if they cannot identify the 
animals to species with confidence. In those cases, they shall note any 
information that might aid in the identification of the marine mammal 
sighted. For example, for an unidentified mysticete whale, the 
observers should record whether the animal had a dorsal fin.
    n. Additional details about unidentified marine mammal sightings, 
such as ``blow only'', mysticete with (or without) a dorsal fin, ``seal 
splash'', etc., shall be recorded.
    o. BP shall conduct a fish and airgun sound monitoring program as 
described in the IHA application and further refined in consultation 
with an expert panel.
    9. Data Analysis and Presentation in Reports:
    a. Estimation of potential takes or exposures shall be improved for 
times with low visibility (such as during fog

[[Page 21549]]

or darkness) through interpolation or possibly using a probability 
approach. Those data could be used to interpolate possible takes during 
periods of restricted visibility.
    b. Water depth should be continuously recorded by the vessel and 
for each marine mammal sighting. Water depth should be accounted for in 
the analysis of take estimates.
    c. BP shall be very clear in their report about what periods are 
considered ``non-seismic'' for analyses.
    d. BP shall examine data from ASAMM and other such programs to 
assess possible impacts from their seismic survey.
    e. To better assess impacts to marine mammals, data analysis shall 
be separated into periods when a seismic airgun array (or a single 
mitigation airgun) is operating and when it is not. Final and 
comprehensive reports to NMFS should summarize and plot:
    i. Data for periods when a seismic array is active and when it is 
not; and
    ii. The respective predicted received sound conditions over fairly 
large areas (tens of km) around operations.
    f. To help evaluate the effectiveness of PSOs and more effectively 
estimate take, if appropriate data are available, BP shall perform 
analysis of sightability curves (detection functions) for distance-
based analyses.
    g. BP should improve take estimates and statistical inference into 
effects of the activities by incorporating the following measures:
    i. Reported results from all hypothesis tests should include 
estimates of the associated statistical power when practicable.
    ii. Estimate and report uncertainty in all take estimates. 
Uncertainty could be expressed by the presentation of confidence 
limits, a minimum-maximum, posterior probability distribution, etc.; 
the exact approach would be selected based on the sampling method and 
data available.
    10. Reporting Requirements: The Holder of this Authorization is 
required to:
    a. A report will be submitted to NMFS within 90 days after the end 
of the proposed seismic survey. The report will summarize all 
activities and monitoring results conducted during in-water seismic 
surveys. The Technical Report will include the following:
    i. Summary of project start and end dates, airgun activity, number 
of guns, and the number and circumstances of implementing ramp-up, 
power down, shutdown, and other mitigation actions;
    ii. Summaries of monitoring effort (e.g., total hours, total 
distances, and marine mammal distribution through the study period, 
accounting for sea state and other factors affecting visibility and 
detectability of marine mammals);
    iii. Analyses of the effects of various factors influencing 
detectability of marine mammals (e.g., sea state, number of observers, 
and fog/glare);
    iv. Species composition, occurrence, and distribution of marine 
mammal sightings, including date, water depth, numbers, age/size/gender 
categories (if determinable), and group sizes;
    v. Analyses of the effects of survey operations;
    vi. Sighting rates of marine mammals during periods with and 
without seismic survey activities (and other variables that could 
affect detectability), such as:
    A. Initial sighting distances versus survey activity state;
    B. Closest point of approach versus survey activity state;
    C. Observed behaviors and types of movements versus survey activity 
state;
    D. Numbers of sightings/individuals seen versus survey activity 
state;
    E. Distribution around the source vessels versus survey activity 
state; and
    F. Estimates of exposures of marine mammals to Level B harassment 
thresholds based on presence in the 160 dB harassment zone.
    b. The draft report will be subject to review and comment by NMFS. 
Any recommendations made by NMFS must be addressed in the final report 
prior to acceptance by NMFS. The draft report will be considered the 
final report for this activity under this Authorization if NMFS has not 
provided comments and recommendations within 90 days of receipt of the 
draft report.
    c. BP will present the results of the fish and airgun sound study 
to NMFS in a detailed report.
11. Notification of Dead or Injured Marine Mammals
    a. In the unanticipated event that the specified activity clearly 
causes the take of a marine mammal in a manner prohibited by the IHA, 
such as an injury (Level A harassment), serious injury or mortality 
(e.g., ship-strike, gear interaction, and/or entanglement), BP would 
immediately cease the specified activities and immediately report the 
incident to the Chief of the Permits and Conservation Division, Office 
of Protected Resources, NMFS, and the Alaska Regional Stranding 
Coordinators. The report would include the following information:
     Time, date, and location (latitude/longitude) of the 
incident;
     Name and type of vessel involved;
     Vessel's speed during and leading up to the incident;
     Description of the incident;
     Status of all sound source use in the 24 hours preceding 
the incident;
     Water depth;
     Environmental conditions (e.g., wind speed and direction, 
Beaufort sea state, cloud cover, and visibility);
     Description of all marine mammal observations in the 24 
hours preceding the incident;
     Species identification or description of the animal(s) 
involved;
     Fate of the animal(s); and
     Photographs or video footage of the animal(s) (if 
equipment is available).
    Activities would not resume until NMFS is able to review the 
circumstances of the prohibited take. NMFS would work with BP to 
determine what is necessary to minimize the likelihood of further 
prohibited take and ensure MMPA compliance. BP would not be able to 
resume their activities until notified by NMFS via letter, email, or 
telephone.
    b. In the event that BP discovers an injured or dead marine mammal, 
and the lead PSO determines that the cause of the injury or death is 
unknown and the death is relatively recent (i.e., in less than a 
moderate state of decomposition as described in the next paragraph), BP 
would immediately report the incident to the Chief of the Permits and 
Conservation Division, Office of Protected Resources, NMFS, and the 
NMFS Alaska Stranding Hotline and/or by email to the Alaska Regional 
Stranding Coordinators. The report would include the same information 
identified in the paragraph above. Activities would be able to continue 
while NMFS reviews the circumstances of the incident. NMFS would work 
with BP to determine whether modifications in the activities are 
appropriate.
    c. In the event that BP discovers an injured or dead marine mammal, 
and the lead PSO determines that the injury or death is not associated 
with or related to the activities authorized in the IHA (e.g., 
previously wounded animal, carcass with moderate to advanced 
decomposition, or scavenger damage), BP would report the incident to 
the Chief of the Permits and Conservation Division, Office of Protected 
Resources, NMFS, and the NMFS Alaska Stranding Hotline and/or by email 
to the Alaska Regional Stranding Coordinators, within 24 hours of the 
discovery. BP would provide photographs or video footage (if available) 
or other documentation of the stranded animal sighting to NMFS and the 
Marine Mammal Stranding Network.
    12. Activities related to the monitoring described in this IHA do 
not require a separate scientific research

[[Page 21550]]

permit issued under section 104 of the MMPA.
    13. BP is required to comply with the Reasonable and Prudent 
Measures and Terms and Conditions of the Incidental Take Statement 
(ITS) corresponding to NMFS' Biological Opinion.
    14. A copy of this IHA and the ITS must be in the possession of all 
contractors and PSOs operating under the authority of this IHA.
    15. Penalties and Permit Sanctions: Any person who violates any 
provision of this Incidental Harassment Authorization is subject to 
civil and criminal penalties, permit sanctions, and forfeiture as 
authorized under the MMPA.
    16. This Authorization may be modified, suspended or withdrawn if 
the Holder fails to abide by the conditions prescribed herein or if the 
authorized taking is having more than a negligible impact on the 
species or stock of affected marine mammals, or if there is an 
unmitigable adverse impact on the availability of such species or 
stocks for subsistence uses.

Request for Public Comments

    NMFS requests comment on our analysis, the draft authorization, and 
any other aspect of the Notice of Proposed IHA for BP's proposed 
shallow geohazard survey in the Foggy Island Bay area of the Beaufort 
Sea, Alaska, during the 2014 open-water season. Please include with 
your comments any supporting data or literature citations to help 
inform our final decision on BP's request for an MMPA authorization.

    Dated: April 10, 2014.
Donna S. Wieting,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. 2014-08534 Filed 4-15-14; 8:45 am]
BILLING CODE 3510-22-P