[Federal Register Volume 73, Number 123 (Wednesday, June 25, 2008)]
[Notices]
[Pages 36044-36062]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E8-14393]



[[Page 36044]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XD76


Taking Marine Mammals Incidental to Specified Activities; Seismic 
Surveys in the Beaufort and Chukchi Seas

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

ACTION: Notice of receipt of application and proposed incidental take 
authorization; request for comments.

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SUMMARY: NMFS has received an application from Shell Offshore, Inc. 
(SOI) and its contractor WesternGeco for an Incidental Harassment 
Authorization (IHA) to take small numbers of marine mammals, by 
harassment, incidental to conducting marine geophysical programs, 
including deep seismic surveys, on oil and gas lease blocks located on 
Outer Continental Shelf (OCS) waters in the Beaufort and Chukchi Seas. 
Under the Marine Mammal Protection Act (MMPA), NMFS is requesting 
comments on its proposal to issue an IHA to SOI and WesternGeco to 
incidentally take, by Level B harassment, small numbers of several 
species of marine mammals during the Arctic Ocean open-water seasons 
between August 1, 2008 and July 31, 2009, incidental to conducting 
these seismic surveys.

DATES: Comments and information must be received no later than July 25, 
2008.

ADDRESSES: Written comments on the application should be addressed to 
Mr. P. Michael Payne, Chief, Permits, Conservation and Education 
Division, Office of Protected Resources, National Marine Fisheries 
Service, 1315 East-West Highway, Silver Spring, MD 20910-3225, or by 
telephoning the contact listed here. The mailbox address for providing 
email comments is [email protected]. Comments sent via e-mail, 
including all attachments, must not exceed a 10-megabyte file size.
    A copy of the application (containing a list of the references used 
in this document) may be obtained by writing to this address or by 
telephoning the contact listed here and are also available at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha.
    A copy of the Minerals Management Service (MMS) Final Programmatic 
Environmental Assessment (Final PEA) and the NMFS/MMS Draft 
Programmatic Environmental Impact Statement (Draft PEIS) are available 
at: http://www.mms.gov/alaska/.
    Documents cited in this document that are not available through 
standard public library access methods, may be viewed, by appointment, 
during regular business hours at this address.

FOR FURTHER INFORMATION CONTACT: Kenneth Hollingshead, Office of 
Protected Resources, NMFS, (301) 713-2289, or Brad Smith, NMFS, Alaska 
Regional Office 907-271-3023.

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 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.
    An authorization shall be granted if NMFS finds that the taking 
will have a negligible impact on the species or stock(s) and will not 
have an unmitigable adverse impact on the availability of the species 
or stock(s) for subsistence uses and the permissible methods of taking 
and requirements pertaining to the mitigation, monitoring and reporting 
of such takings are set forth. NMFS has defined ``negligible impact'' 
in 50 CFR 216.103 as ''...an impact resulting from the specified 
activity that cannot be reasonably expected to, and is not reasonably 
likely to, adversely affect the species or stock through effects on 
annual rates of recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by 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].

    Section 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
marine mammals. Within 45 days of the close of the comment period, NMFS 
must either issue or deny the authorization.

Summary of Request

    On October 16, 2007, NMFS received an application from SOI for the 
taking, by harassment, of several species of marine mammals incidental 
to conducting a marine seismic survey program during the open water 
season between August 1, 2008 and July 31, 2009 (referred to in this 
document as 2008/2009). SOI is planning a variety of programs in the 
Chukchi and Beaufort Seas during the 2008/2009 open water seasons, 
including a: (1) Chukchi Sea deep 3-D seismic survey; (2) Beaufort Sea 
deep 3-D seismic survey; and (3) Beaufort Sea marine surveys, which 
includes three activities: (a) site clearance and shallow hazards 
surveys; (b) an ice-gouge survey; and (c) a strudel scour survey.
    The deep seismic survey components of the program will be conducted 
from WesternGeco's vessel, M/V Gilavar. Detailed specifications on this 
seismic survey vessel are provided in Attachment A of SOI's IHA 
application. These specifications include: (1) complete descriptions of 
the number and lengths of the streamers which form the hydrophone 
arrays; (2) airgun size and sound propagation properties; and (3) 
additional detailed data on the M/V Gilavar's characteristics. In 
summary, the M/V Gilavar will tow two source arrays, comprising three 
identical subarrays each, which will be fired alternately as the ship 
progresses downline in the survey area. The M/V Gilavar will tow up to 
6 streamer cables up to 5.4 kilometers (km)(3.4 mi) long. With this 
configuration each pass of the M/V Gilavar can record 12 subsurface 
lines spanning a swath of up to 360 meters (1181 ft). The seismic 
acquisition vessel will be supported by the M/V Gulf Provider, or a 
similar vessel. The M/V Gulf Provider will serve as a crew change, 
resupply, fueling support of acoustic and marine mammal monitoring, and 
seismic chase vessel. It will not deploy seismic acquisition gear.
    As SOI's 2007 IHA for open water seismic activities in the Chukchi 
and Beaufort Seas is valid until August 1, 2008, this IHA request is 
intended, therefore, for the open water seasons between August 2, 2008 
through July 31, 2009.
    As marine mammals may be affected by seismic and vessel noise, SOI 
has requested an authorization under section 101(a)(5)(D) of the MMPA 
to

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take marine mammals by Level B harassment while conducting seismic 
surveys and related activities.

Plan for Seismic Operations

    In its application, SOI notes that it plans for the M/V Gilavar to 
be in the Chukchi Sea to begin seismic acquisition data on or after 
July 20, 2008, move to the Beaufort Sea in mid-July through late 
October, and conclude work in the Chukchi Sea around November 15, 2008. 
For purposes of the MMPA, the Chukchi and Beaufort seas meet the 
definition of a ``specific geographic region'' as defined under the 
Act. As proposed, the 2008 seismic survey effort will last a maximum of 
100 days of active data acquisition (excluding downtime due to weather 
and other unforeseen delays). When ice conditions permit or when SOI 
determines to do so (at present, SOI plans to work in the Chukchi Sea 
until around September 25), the seismic and associated vessels will 
transit to the Beaufort Sea to conduct seismic operation for part of 
the this 100-day period. The proposed commencement date of July 20th 
for starting seismic in the Chukchi Sea is designed to ensure that 
there will be no conflict with the spring bowhead whale migration and 
subsistence hunts conducted by Barrow, Pt. Hope, or Wainwright or the 
beluga subsistence hunt conducted by the village of Pt. Lay in early 
July. The approximate area of SOI's seismic survey operations are shown 
in Figure 1 in SOI's IHA application.

3-D Deep Seismic Surveys

Chukchi Sea 3-D Deep Seismic Surveys
    SOI and its geophysical (seismic) contractor, WesternGeco, propose 
to conduct a marine geophysical (deep 3-D seismic) survey program 
during open water season on various MMS Outer Continental Shelf (OCS) 
lease blocks in the northern Chukchi Sea (see Figure 1 in SOI's IHA 
application). The Chukchi Sea 3-D Deep Seismic survey will be conducted 
on leases obtained under Lease Sale (LS) 193. The exact locations where 
operations will occur within that sale area were not known at the time 
of SOI's IHA application, but NMFS presumes they will take place on 
lease blocks obtained as a result of the sale. However, in general SOI 
notes that the seismic data acquisition will occur at least 25 mi (40 
km) offshore of the coast and in waters with depths averaging about 40 
m (131 ft).
    The deep 3-D seismic survey is proposed to be conducted from 
WesternGeco's vessel M/V Gilavar, described previously. Two ``chase 
boats'' will accompany the seismic vessel. These two chase boats will 
provide the following functions: (1) re-supply, (2) marine mammal 
monitoring, (3) ice scouting, and (4) general support for the M/V 
Gilavar. The chase boat vessels proposed for use in 2008 are the M/V 
Theresa Marie and the M/V Torsvik. These vessels will not deploy any 
seismic gear. In addition, a crew change vessel, the M/V Gulf Provider 
or similar vessel and a landing craft, such as the M/V Maxime or 
similar vessel, will support the M/V Gilavar, and the two chase boats 
in the Chukchi Sea. The crew change vessel will be used to move 
personnel and supplies from the seismic vessel, and two chase boats to 
the nearshore areas. In turn, the landing craft will move personnel and 
supplies from the crew change vessel, when it is located in nearshore 
areas, to the beach (most likely this will be at Barrow). Lastly, the 
Marine Mammal Monitoring and Mitigation Program (4MP) will have a 
separate vessel for the proposed 2008 Program. The landing craft also 
will be used to move personnel and equipment from the 4MP vessel to the 
near shore areas.
Beaufort Sea Deep 3-D Seismic Surveys
    The same seismic vessel (M/V Gilavar), seismic equipment, and chase 
boats that are described for the Chukchi Sea Deep 3-D Seismic survey, 
will be used to conduct deep 3-D seismic surveys in the central and 
eastern Beaufort Sea (see Figure 2 in SOI's IHA application). The focus 
of this activity will be on SOI's existing leases, but some activity in 
the Beaufort Sea may occur outside of SOI's existing leases. The 
landing craft, which will be used to move personnel and supplies from 
vessels in the near shore to docking sites will most likely use West 
Dock, or Oliktok Dock. Smaller vessels such as the Alaska Clean Seas 
(ACS) bay boats, or similar vessels, may be used to assist in the 
movement of people and supplies and support of the 4MP in the Beaufort 
Sea. The specific geographic region for SOI's deep seismic program in 
the Beaufort Sea will be in OCS waters including SOI leases beginning 
east of the Colville River delta to west of the village of Kaktovik 
(see Figure 2 in SOI's application). According to SOI's IHA 
application, the Beaufort Sea program is planned to occur for a maximum 
of 60 days (excluding downtime due to weather and unforeseen delays) 
during open-water from mid-August to the end of October; however, 
recent communications with SOI indicates that the Beaufort Sea seismic 
program will not start until after September 25, 2008. This timing of 
activities in the fall will avoid any significant conflict with the 
Beaufort Sea bowhead whale subsistence hunt conducted by the Beaufort 
Sea villages, because it is anticipated that the fall bowhead whale 
hunt will have ended by that time.
Description of Marine 3-D Seismic Data Acquisition
    In the seismic method, reflected sound energy produces graphic 
images of seafloor and sub-seafloor features. The seismic system 
consists of sources and detectors, the positions of which must be 
accurately measured at all times. The sound signal comes from arrays of 
towed energy sources. These energy sources store compressed air which 
is released on command from the towing vessel. The released air forms a 
bubble which expands and contracts in a predictable fashion, emitting 
sound waves as it does so. Individual sources are configured into 
arrays. These arrays have an output signal, which is more desirable 
than that of a single bubble, and also serve to focus the sound output 
primarily in the downward direction, which is useful for the seismic 
method. This array effect also minimizes the sound emitted in the 
horizontal direction.
    The downward propagating sound travels to the seafloor and into the 
geologic strata below the seafloor. Changes in the acoustic properties 
between the various rock layers result in a portion of the sound being 
reflected back toward the surface at each layer. This reflected energy 
is received by detectors called hydrophones, which are housed within 
submerged streamer cables which are towed behind the seismic vessel. 
Data from these hydrophones are recorded to produce seismic records or 
profiles. Seismic profiles often resemble geologic cross- sections 
along the course traveled by the survey vessel.
Description of WesternGeco's Air-Gun Array
    SOI is proposing to use WesternGeco's 3147-in\3\ Bolt-Gun Array for 
its 3-D seismic survey operations in the Chukchi and Beaufort Seas. 
WesternGeco's source arrays are composed of 3 identically tuned Bolt-
gun sub-arrays operating at an air pressure of 2,000 psi. In general, 
the signature produced by an array composed of multiple sub-arrays has 
the same shape as that produced by a single sub-array while the overall 
acoustic output of the array is determined by the number of sub-arrays 
employed.
    The airgun arrangement for each of the three 1049-in\3\ sub-array 
is detailed in SOI's application. As indicated in the

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application's diagram, each sub-array is composed of six tuning 
elements; two 2-airgun clusters and four single airguns. The standard 
configuration of a source array for 3-D surveys consists of one or more 
1049-in\3\ sub-arrays. When more than one sub-array is used, as here, 
the strings are lined up parallel to each other with either 8 m or 10 m 
(26 or 33 ft) cross-line separation between them. This separation was 
chosen so as to minimize the areal dimensions of the array in order to 
approximate point source radiation characteristics for frequencies in 
the nominal seismic processing band. For the 3147-in\3\ array the 
overall dimensions of the array are 15 m (49 ft) long by 16-m (52.5-ft) 
wide.
Characteristics of Airgun Pulses
    A discussion of the characteristics of airgun pulses was provided 
in several previous Federal Register documents (see 69 FR 31792 (June 
7, 2004) or 69 FR 34996 (June 23, 2004)) and is not repeated here. 
Additional information can be found in the NMFS/MMS Draft PEIS (see 
ADDRESSES). Reviewers are encouraged to read these earlier documents 
for additional background information.

Marine Surveys

    SOI proposes to conduct marine surveys (shallow hazards and other 
activities) in the Beaufort and Chukchi seas in 2008. Acoustic systems 
similar to the ones proposed for use by SOI during its planned marine 
surveys have been described by NMFS previously (see 66 FR 40996 (August 
6, 2001), 70 FR 13466 (March 21, 2005)). NMFS encourages readers to 
refer to these documents for additional information on these systems. A 
summary of SOI's planned activities is described next.
Beaufort Sea Marine Surveys
    SOI proposes to conduct three marine survey activities in 2008 in 
the U.S. Beaufort Sea: (1) Site Clearance and Shallow Hazards (2) Ice 
Gouge Surveys, and (3) Strudel Scour Surveys. Marine surveys for site 
clearance and shallow hazards, ice gouge, or strudel scour in the 
Beaufort Sea can be accomplished by the M/V Henry Christofferson. No 
other vessels, such as chase boats, are necessary to accomplish the 
proposed marine survey work. Any necessary crew changes or 4MP 
coordinated activities under this activity will utilize the same crew 
change, landing craft, or 4MP vessel mentioned under the Beaufort Sea 
Deep 3-D Seismic survey.
Site Clearance and Shallow Hazards
    Marine surveys will include site clearance and shallow hazards 
surveys of potential exploratory drilling locations. These surveys 
gather data on: (1) bathymetry, (2) seabed topography and other seabed 
characteristics (e.g., boulder patches), (3) potential geohazards 
(e.g., shallow faults and shallow gas zones), and (4) the presence of 
any archeological features (e.g., shipwrecks).
    The focus of this activity will be on SOI's existing leases in the 
central and eastern Beaufort Sea, but some activity may occur outside 
of SOI's existing leases. Actual locations of site clearance and 
shallow hazard surveys have not been definitively set as of the date of 
this publication, although they will occur within the area outlined in 
Figure 2 of SOI's IHA application.
    The vessel that SOI expects to use for the site clearance and 
shallow hazards surveys is the M/V Henry Christofferson, which is a 
diesel-powered tug as described in Attachment A to SOI's IHA 
application. SOI proposes to use the following acoustic 
instrumentation, (or similar equipment) during this work. This is the 
same equipment as was used on the M/V Henry Christofferson during 2007:
    (1) Dual frequency subbottom profiler Datasonics CAP6000 Chirp II 
(2 to7 kiloHertz [kHz] or 8 to 23 kHz) or similar;
    (2) Medium penetration subbottom profiler, Datasonics SPR-1200 
Bubble Pulser (400 (hertz [Hz]) or similar;
    (3) High resolution multi-channel 2D system, 20 cubic inches 
(in\3\) (2 by 10) gun array (0 to 150 Hz) or similar;
    (4) Multi-beam bathymetric sonar, Seabat 8101 (240 Hz); or similar; 
and
    (5) Side-scan sonar system, Datasonics SIS-1500 (190 to 210 kHz) or 
similar.
Ice Gouge Survey
    Ice gouge surveys are a type of marine survey to determine the 
depth and distribution of ice gouges in the sea bed. Ice gouge is 
created by ice keels which project from the bottom of moving ice that 
gouge into seafloor sediment. Remnant ice gouge features are mapped to 
aid in predicting the prospect of, orientation, depth, and frequency of 
future ice gouge. These surveys will focus on the potential, 
prospective pipeline corridor between the Sivulliq Prospect in Camden 
Bay and the nearshore Point Thomson area. The Sivulliq area will be 
surveyed to gather geotechnical and seafloor hazard information as well 
as data on ice gouges.
    SOI proposes that the acoustic instrumentation described previously 
in this document (or something similar) will be used, namely multi-beam 
bathymetric sonar, side scan sonar and subbottom profiling. Actual 
locations of the ice gouge surveys have not been definitively set as of 
the date of this publication, although these will occur within the area 
outlined in Figure 2 of SOI's IHA application. There are also some 
platform siting lines proposed, which would employ a high resolution 
multi-channel 2D system, 20 cubic inches (in\3\) (2 by 10) airgun array 
(0 to 150 Hz) or similar system.
Strudel Scour Survey
    During the early melt on the North Slope, the rivers begin to flow 
and discharge water over the coastal sea ice near the river deltas. 
That water rushes down holes in the ice (``strudels'') and scours the 
seafloor. These erosional areas are called ``strudel scours''. 
Information on these features is required for prospective pipeline 
planning. Two proposed activities are required to gather this 
information.
    First, an aerial survey will be conducted via helicopter 
overflights during the melt to locate the strudels; and strudel scour 
marine surveys to gather bathymetric data. The overflights investigate 
possible sources of overflood water and will survey local streams that 
discharge in the vicinity of Point Thomson including the Staines River, 
which discharges to the east into Flaxman Lagoon and the Canning River, 
which discharges to the east directly into the Beaufort Sea. These 
helicopter overflights were scheduled to occur during late May/early 
June 2008 and, weather permitting, should take no more than four days. 
There are no planned landings during these overflights other than at 
the Deadhorse or Kaktovik airports.
    Second, areas that have strudel scour identified during the aerial 
survey will be verified and surveyed with a marine vessel after the 
breakup of nearshore ice. This proposed activity is not anticipated to 
take more than 5 days to conduct. The operation is conducted in the 
shallow water areas near the coast in the vicinity of Point Thomson. 
The vessel has not been contracted; however, it is anticipated that it 
will be the diesel-powered R/V Annika Marie. This vessel will use the 
following equipment:
    (1) Multi-beam bathymetric sonar, Seabat 8101 (240 Hz); or similar 
sonar; and
    (2) Side-scan sonar system, Datasonics SIS-1500 (190 to 210 kHz) or 
similar sonar.
    The multi-beam bathymetric sonar and the side-scan sonar systems 
both operate at frequencies greater than 180

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kHz, the highest frequency considered by knowledgeable marine mammal 
biologists to be of possible influence to marine mammals. Because no 
taking of marine mammals will occur from this equipment, no 
measurements of those two sources are planned by SOI, and no exclusion 
zones for seals or whales would be established during operation of 
those two sources. The acoustic instrumentation used on the seismic 
vessels are described in SOI's IHA application.
Chukchi Sea Marine Surveys
    Marine surveys will include site clearance and shallow hazards 
surveys of potential exploratory drilling locations as required by MMS 
regulations. These surveys gather data on: (1) bathymetry, (2) seabed 
topography and other seabed characteristics (e.g., boulder patches), 
(3) potential geohazards (e.g., shallow faults and shallow gas zones), 
and (4) the presence of any archeological features (e.g., shipwrecks). 
Marine surveys for site clearance and shallow hazards can be 
accomplished by one vessel with acoustic sources. No other vessels, 
such as chase boats, are necessary to accomplish the proposed work. Any 
necessary crew changes or 4MP coordinated activities under this 
activity will utilize the same crew change, landing craft, or 4MP 
vessel mentioned under the Chukchi Sea deep 3D seismic surveys.
    The Chukchi Sea marine surveys will be conducted by SOI on leases 
acquired in OCS LS 193. Site clearance surveys are confined to small 
specific areas within OCS blocks. Actual locations of site clearance 
and shallow hazard surveys have not been definitively set as of the 
date of SOI's IHA application, although these will occur within the 
general area outlined in Figure 1 in SOI's IHA application. Before the 
commencement of operations, survey location information will be 
supplied to NMFS, MMS, other agencies and affected members of the 
public as it becomes available. SOI has not contracted for a vessel at 
the time of publication of this document.

Additional Information

    A detailed description of the work proposed by SOI for the open-
water seasons of 2008/2009 is contained in SOI's application which is 
available for review (see ADDRESSES). Also, a description of SOI's data 
acquisition program proposed for the 2008/2009 season, and 
WesternGeco's air-gun array to be employed during 2008/2009 has been 
provided in previous IHA notices on SOI's seismic program (see 71 FR 
26055, May 3, 2006; 71 FR 50027, August 24, 2006).

Description of Habitat and Marine Mammals Affected by the Activity

    A detailed description of the Beaufort and Chukchi sea ecosystems 
and their associated marine mammal populations can be found in the 
NMFS/MMS Draft PEIS and the MMS Final Programmatic Environmental 
Assessment (Final PEA) on Seismic Surveys (see ADDRESSES for 
availability) and also in several other documents (e.g., MMS, 2007 
Final EIS for Chukchi Sea Planning Area: Oil and Gas Lease Sale 193 and 
Seismic Surveying Activities in the Chukchi Sea. MMS 2007-026).

Marine Mammals

    The Beaufort/Chukchi Seas support a diverse assemblage of marine 
mammals, including bowhead whales, gray whales, beluga whales, killer 
whales, harbor porpoise, ringed seals, spotted seals, bearded seals, 
walrus and polar bears. These latter two species are under the 
jurisdiction of the U.S. Fish and Wildlife Service (USFWS) and are not 
discussed further in this document. Descriptions of the biology and 
distribution of the marine mammal species under NMFS' jurisdiction can 
be found in SOI's IHA application, the 2007 NMFS/MMS Draft PEIS on 
Arctic Seismic Surveys, and the MMS 2006 Final PEA on Arctic Seismic 
Surveys. Information on these marine mammal species can also be found 
in NMFS Stock Assessment Reports (SARS). The 2007 Alaska SARS document 
is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2007.pdf. 
Please refer to those documents for information on these species.

Potential Effects of Seismic Surveys on Marine Mammals

    Disturbance by seismic noise is the principal means of taking by 
this activity. Support vessels and aircraft may provide a potential 
secondary source of noise. The physical presence of vessels and 
aircraft could also lead to non-acoustic effects on marine mammals 
involving visual or other cues.
    As outlined in previous NMFS documents, the effects of noise on 
marine mammals are highly variable, and can, in general, be categorized 
as follows (based on Richardson et al., 1995):
    (1) The noise may be too weak to be heard at the location of the 
animal (i.e., lower than the prevailing ambient noise level, the 
hearing threshold of the animal at relevant frequencies, or both);
    (2) The noise may be audible but not strong enough to elicit any 
overt behavioral response;
    (3) The noise may elicit reactions of variable conspicuousness and 
variable relevance to the well being of the marine mammal; these can 
range from temporary alert responses to active avoidance reactions such 
as vacating an area at least until the noise event ceases;
    (4) Upon repeated exposure, a marine mammal may exhibit diminishing 
responsiveness (habituation), or disturbance effects may persist; the 
latter is most likely with sounds that are highly variable in 
characteristics, infrequent and unpredictable in occurrence, and 
associated with situations that a marine mammal perceives as a threat;
    (5) Any anthropogenic noise that is strong enough to be heard has 
the potential to reduce (mask) the ability of a marine mammal to hear 
natural sounds at similar frequencies, including calls from 
conspecifics, and underwater environmental sounds such as surf noise;
    (6) If mammals remain in an area because it is important for 
feeding, breeding or some other biologically important purpose even 
though there is chronic exposure to noise, it is possible that there 
could be noise-induced physiological stress; this might in turn have 
negative effects on the well-being or reproduction of the animals 
involved; and
    (7) Very strong sounds have the potential to cause temporary or 
permanent reduction in hearing sensitivity. In terrestrial mammals, and 
presumably marine mammals, received sound levels must far exceed the 
animal's hearing threshold for there to be any temporary threshold 
shift (TTS) in its hearing ability. For transient sounds, the sound 
level necessary to cause TTS is inversely related to the duration of 
the sound. Received sound levels must be even higher for there to be 
risk of permanent hearing impairment. In addition, intense acoustic or 
explosive events may cause trauma to tissues associated with organs 
vital for hearing, sound production, respiration and other functions. 
This trauma may include minor to severe hemorrhage.

Effects of Seismic Survey Sounds on Marine Mammals

Behavioral Effects

    In its IHA application, SOI states that the only anticipated 
impacts to marine mammals associated with noise propagation from vessel 
movement and seismic airgun operations would be the

[[Page 36048]]

temporary and short term displacement of whales and seals from within 
ensonified zones produced by such noise sources. Any impacts on the 
whale and seal populations of the Beaufort and Chukchi Seas activity 
areas are likely to be short-term and transitory arising from the 
temporary displacement of individuals or small groups from locations 
they may occupy at the times they are exposed to seismic sounds between 
the 160- to 190-dB received levels. In the case of bowhead whales 
however, that displacement might well take the form of a deflection of 
the swim paths of migrating bowheads away from (seaward of) received 
noise levels lower than 160 db (Richardson et al., 1999). Moreover, it 
is not presently known at what distance after passing the seismic 
source that bowheads will return to their previous migration route. 
However, NMFS does not believe that this offshore deflection is 
biologically significant (although it might be significant for purposes 
of subsistence hunting, as discussed later) as the bowhead migration is 
believed to remain within the general bowhead whale migratory corridor 
in the U.S. Beaufort Sea, which varies annually based on environmental 
factors.
    SOI cites Richardson and Thomson [eds]. (2002) to support its 
contention that there is no conclusive evidence that exposure to sounds 
exceeding 160 dB have displaced bowheads from feeding activity. NMFS 
notes that, in 2006, observations conducted onboard a seismic vessel 
operating in the Canadian Beaufort Sea found that feeding bowhead 
whales were not observed to respond to seismic sounds at levels of 160 
dB or lower.
    Results from the 1996-1998 BP and Western Geophysical seismic 
monitoring programs in the Beaufort Sea indicate that most fall 
migrating bowheads deflected seaward to avoid an area within about 20 
km (12.4 mi) of an active nearshore seismic operation, with the 
exception of a few closer sightings when there was an island or very 
shallow water between the seismic operations and the whales (Miller et 
al., 1998, 1999). The available data do not provide an unequivocal 
estimate of the distance (and received sound levels) at which 
approaching bowheads begin to deflect, but this may be on the order of 
35 km (21.7 mi).
    When the received levels of noise exceed some threshold, cetaceans 
will show behavioral disturbance reactions. The levels, frequencies, 
and types of noise that will elicit a response vary between and within 
species, individuals, locations, and seasons. Behavioral changes may be 
subtle alterations in surface, respiration, and dive cycles. More 
conspicuous responses include changes in activity or aerial displays, 
movement away from the sound source, or complete avoidance of the area. 
The reaction threshold and degree of response also are related to the 
activity of the animal at the time of the disturbance. Whales engaged 
in active behaviors, such as feeding, socializing, or mating, appear 
less likely than resting animals to show overt behavioral reactions, 
unless the disturbance is perceived as directly threatening.

Masking

    Although NMFS believes that some limited masking of low-frequency 
sounds (e.g., whale calls) is a possibility during seismic surveys, the 
intermittent nature of seismic source pulses (1 second in duration 
every 16 to 24 seconds (i.e., less than 7 percent duty cycle)) will 
limit the extent of masking. Bowhead whales are known to continue 
calling in the presence of seismic survey sounds, and their calls can 
be heard between seismic pulses (Greene et al., 1999, Richardson et 
al., 1986). Masking effects are expected to be absent in the case of 
belugas, given that sounds important to them are predominantly at much 
higher frequencies than are airgun sounds.

Injury and Mortality

    NMFS and SOI believe that there is no evidence that bowheads or 
other marine mammals exposed to seismic sounds in the Arctic have 
incurred an injury to their auditory mechanisms. While it is not 
positively known whether the hearing systems of marine mammals very 
close to an airgun would be at risk of temporary or permanent hearing 
impairment, Richardson et al. (1995) notes that TTS is a theoretical 
possibility for animals within a few hundred meters of the source. More 
recently, scientists have determined that the received level of a 
single seismic pulse might need to be ~210 dB re 1 [mu]Pa rms (~221-226 
dB pk-pk) in order to produce brief, mild TTS. Exposure to several 
seismic pulses at received levels near 200-205 dB (rms) might result in 
slight TTS in a small odontocete, assuming the TTS threshold is a 
function of the total received pulse energy. Seismic pulses with 
received levels of 200-205 dB or more are usually restricted to a 
radius of no more than 200 m (656 ft) around a seismic vessel operating 
a large array of airguns. For baleen whales, there are no data, direct 
or indirect, on levels or properties of sound that are required to 
induce TTS. However, according to SOI, there is a strong likelihood 
that baleen whales (i.e., bowheads, gray whales and humpback whales) 
would avoid the approaching airguns (or vessel) before being exposed to 
levels high enough for there to be any possibility of onset of TTS.
    For pinnipeds, information indicates that for single seismic 
impulses, sounds would need to be higher than 190 dB rms for TTS to 
occur while exposure to several seismic pulses indicates that some 
pinnipeds may incur TTS at somewhat lower received levels than do small 
odontocetes exposed for similar durations. This indicates to NMFS that 
the 190-dB safety zone (see Mitigation and Monitoring later in this 
document) provides a sufficient buffer to prevent permanent threshold 
shift (PTS) in pinnipeds.
    A marine mammal within a radius of <=100 m (<=328 ft) around a 
typical large array of operating airguns may be exposed to a few 
seismic pulses at received levels of [gteqt]205 dB, and possibly more 
pulses if the marine mammal moved with the seismic vessel. When PTS 
occurs, there is physical damage to the sound receptors in the ear. In 
some cases, there can be total or partial deafness, whereas in other 
cases, the animal has an impaired ability to hear sounds in specific 
frequency ranges. However, as scientists are reluctant to cause injury 
to a marine mammals, there is no specific evidence that exposure to 
pulses of airgun sound can cause PTS in any marine mammal, even with 
large arrays of airguns. Given the possibility that mammals close to an 
airgun array might incur TTS, there has been further speculation about 
the possibility that some individuals occurring very close to airguns 
might incur PTS. Single or occasional occurrences of mild TTS are not 
indicative of permanent auditory damage in terrestrial mammals.
    Relationships between TTS and PTS thresholds have not been studied 
in marine mammals, but are assumed to be similar to those in humans and 
other terrestrial mammals. Acousticians are in general agreement that a 
temporary shift in hearing threshold of up to 40 dB due to moderate 
exposure times is fully recoverable and does not involve tissue damage 
or cell loss. Liberman and Dodds (1987) state, ''... acute threshold 
shifts as large as 60 dB are routinely seen in ears in which the 
surface morphology of the stereocilia is perfectly normal.'' 
(Stereocilia are the sensory cells responsible for the sensation of 
hearing.). In the chinchilla, no cases of TTS involve the loss of 
stereocilia, but all cases of PTS do (Ahroon et al., 1996). Cell death 
clearly qualifies as Level A harassment (injury)

[[Page 36049]]

under the MMPA. Because there is no cell death with modest (up to 40 
dB) TTS, such losses of sensitivity constitute a temporary impairment 
but not an injury, further supporting NMFS' precautionary approach that 
establishment of seismic airgun shutdown at 180 dB for cetaceans and 
190 dB for pinnipeds, will prevent auditory injury to marine mammals by 
seismic airgun sounds.
    NMFS notes that planned monitoring and mitigation measures 
(described later in this document) have been designed to avoid sudden 
onsets of seismic pulses at full power, to detect marine mammals 
occurring near the array, and to avoid exposing them to sound pulses 
that have any possibility of causing hearing impairment. Moreover, NMFS 
does not expect that any marine mammals will be seriously injured or 
killed during SOI's seismic survey activities, even if some animals are 
not detected prior to entering the 180-dB and 190-dB isopleths (safety 
zones) for cetaceans and pinnipeds, respectively. These criteria were 
set to approximate a level below where Level A harassment (i.e., 
defined as ``any act of pursuit, torment or annoyance which has the 
potential to injure a marine mammal or marine mammal stock in the 
wild'') from acoustic sources was believed to begin. Because, a decade 
or so ago, scientists did not have information on where PTS might occur 
in marine mammals, the High Energy Seismic Survey (HESS) workshop 
(HESS, 1997, 1999) set the level to prevent injury to marine mammals at 
180 dB. NMFS concurred and determined that TTS, which is the mildest 
form of hearing impairment that can occur during exposure to a strong 
sound, may occur at these levels (180 dB for cetaceans, 190 dB for 
pinnipeds). When a marine mammal experiences TTS, the hearing threshold 
rises and a sound must be stronger in order to be heard. TTS can last 
from minutes or hours to (in cases of strong TTS) days. For sound 
exposures at or somewhat above the TTS threshold, hearing sensitivity 
recovers rapidly after exposure to the noise ends. Few data on sound 
levels and durations necessary to elicit mild TTS have been obtained 
for marine mammals, and none of the published data concern TTS elicited 
by exposure to multiple pulses of sound.

Strandings

    In numerous past IHA notices for seismic surveys, commenters have 
referenced two stranding events allegedly associated with seismic 
activities, one off Baja California and a second off Brazil. NMFS has 
addressed this concern several times and without new information, does 
not believe that this issue warrants further discussion. For 
information relevant to strandings of marine mammals, readers are 
encouraged to review NMFS' response to comments on this matter found in 
69 FR 74905 (December 14, 2004), 71 FR 43112 (July 31, 2006), 71 FR 
50027 (August 24, 2006), and 71 FR 49418 (August 23, 2006). In 
addition, a June, 2008 stranding of 30-40 melon-headed whales 
(Peponocephala spp), off Madagascar that appears to be associated with 
seismic surveys is currently under investigation. One report indicates 
that the stranding began prior to seismic surveys starting.
    It should be noted that marine mammal strandings recorded in the 
Beaufort and Chukchi seas do not appear to be related to seismic 
surveys. Finally, if bowhead and gray whales react to sounds at very 
low levels by making minor course corrections to avoid seismic noise 
and mitigation measures require SOI to ramp-up the seismic array to 
avoid a startle effect, strandings are unlikely to occur in the Arctic 
Ocean. As a result, NMFS does not expect any marine mammals will incur 
serious injury, mortality or strandings in the Arctic Ocean.

Potential Impacts on Affected Species and Stocks of Marine Mammals

    According to SOI, the only anticipated impacts to marine mammals 
associated with SOI's seismic activities with respect to noise 
propagation are from vessel movements and seismic air gun operations. 
SOI states that these impacts would be temporary and short term 
displacement of seals and whales from within ensonified zones produced 
by such noise sources. Any impacts on the whale and seal populations of 
the Beaufort and Chukchi Sea activity areas are likely to be short term 
and transitory arising from the temporary displacement of individuals 
or small groups from locations they may occupy at the times they are 
exposed to seismic sounds at the 160-190 dB (or higher) received 
levels. As noted elsewhere, it is highly unlikely that animals will be 
exposed to sounds of such intensity and duration as to physically 
damage their auditory mechanisms. In the case of bowhead whales that 
displacement might well take the form of a deflection of the swim paths 
of migrating bowheads away from (seaward of) received noise levels 
greater than 160 db (Richardson et al., 1999). There is no evidence 
that bowheads so exposed have incurred injury to their auditory 
mechanisms. Also, there is no evidence that seals are more than 
temporarily displaced from ensonified zones and no evidence that seals 
have experienced physical damage to their auditory mechanisms even 
within ensonified zones.
    During the period of seismic acquisition in the Chukchi and 
Beaufort seas, most marine mammals are expected to be dispersed 
throughout the area. Bowhead whales are expected to be concentrated in 
the Canadian Beaufort Sea during much of this time, where they are not 
expected to be affected by SOI's seismic program. The peak of the 
bowhead whale migration through the Beaufort and Chukchi seas typically 
occurs in late August through October, and efforts to reduce potential 
impacts during this time will be addressed with the actual start of the 
migration and through discussions with the affected whaling 
communities. In the Chukchi Sea, the timing of seismic activities will 
take place while the whales are widely distributed and would be 
expected to occur in very low numbers within the seismic activity area. 
If SOI conducts seismic surveys in late September or October in the 
Beaufort or Chukchi Sea, bowheads may travel in proximity to the 
seismic survey activity areas and hear sounds from vessel traffic and 
seismic activities, of which some might be displaced by the planned 
activities.
    The reduction of potential impacts during the fall bowhead whale 
migratory period will be addressed through discussions with the whaling 
communities. Starting in late August bowheads may travel in proximity 
to SOI's planned Beaufort Sea seismic activity areas and may hear 
sounds from vessel traffic and seismic activities, of which some might 
be displaced seaward by the planned activities. However, at the present 
time, SOI expects to significantly reduce its period of seismic 
operations in the Beaufort Sea by remaining in the Chukchi Sea until 
mid-September, entering the Beaufort Sea only after the fall 
subsistence hunt has concluded and after a significant portion of the 
bowhead whales would have left the Canadian Beaufort Sea on their 
westward migration to the Chukchi Sea.
    In addition, although there was apparently a period of concentrated 
feeding in the central Beaufort Sea in September 2007, feeding does not 
normally appear to be an important activity by bowheads migrating 
through the eastern and central part of the Alaskan Beaufort Sea or the 
Chukchi Sea in most years. Sightings of bowhead whales occur in the 
summer near Barrow (Moore and DeMaster, 2000), and there are 
suggestions that certain areas near Barrow are important feeding

[[Page 36050]]

grounds. In addition, a few bowheads can be found in the Chukchi and 
Bering Seas during the summer and Rugh et al. (2003) suggests that this 
may be an expansion of the western Arctic stock, although more research 
is needed. In the absence of important feeding areas, the potential 
diversion of a small number of bowheads away from seismic activities is 
not expected to have any significant or long-term consequences for 
individual bowheads or their population.

Effects on Individual Arctic Ocean Marine Mammal Species

    In order to facilitate the reader's understanding of the knowledge 
of impacts of impulsive noise on the principal marine mammal species 
that are expected to be affected by SOI's proposed seismic survey 
program, NMFS has previously provided a summary of potential impacts on 
the bowhead, gray, and beluga whales and the ringed, largha and bearded 
seals. This information can be found in the Federal Register (72 FR 
31553, June 7, 2007). Information on impacts on marine mammals by 
seismic activities can also be found in SOI's IHA application.

Numbers of Marine Mammals Expected to Be Harassed by Seismic Survey 
Activities

    The methodology used by SOI to estimate incidental take by 
harassment by seismic and the numbers of marine mammals that might be 
affected in the proposed seismic acquisition activity area in the 
Chukchi and Beaufort seas has been presented in SOI's 2008 IHA 
application.
    In its application, SOI provides estimates of the number of 
potential ``exposures'' to sound levels equal to or greater than 160 dB 
re 1 [mu]Pa (rms). NMFS clarifies here that, except possibly for 
bowhead whales, calculations of the number of exposures by SOI, does 
not necessarily indicate that this is the number of Level B harassments 
that SOI's seismic activity will take. First, exposure estimates do not 
take into account variability between species or within a species by 
activity, age or sex. What this means is that not all animals are 
expected to react at the same level as its conspecifics, and all 
species are not expected to react at the same level, as some species in 
the Arctic will respond to sounds differently, if at all, depending 
upon whether or not they have good hearing in the same frequency range 
as seismic. Second, NMFS believes that SOI's use of the maximum density 
estimates for its requested take authorization (see IHA application and 
references for details) is overly cautious as it tends to inflate 
harassment take estimates to an unreasonably high number and is not 
based on good empirical science. NMFS believes that these inflated 
numbers have been provided and used by SOI for its Level B harassment 
take request in an abundance of caution because they present a worst-
case estimate. NMFS, on the other hand prefers to use the average 
density estimate numbers provided in Tables 6-1 through 6-5 in SOI's 
IHA application as these are the more realistic and scientifically 
supportable estimates. NMFS notes, for example, that the most 
comprehensive survey data set on ringed and bearded seals from the 
central and eastern Beaufort Sea was conducted on offshore pack ice in 
late spring. Density estimates of ringed and bearded seals were based 
on counts of seals on the ice during this survey, not in open water 
where seismic surveys are conducted. Consequently, the density and 
potential take (exposure) numbers for seals in the Beaufort and Chukchi 
seas will likely overestimate the number of seals that could be 
encountered and/or exposed to seismic airguns because only animals in 
the water near the survey area would be exposed to seismic and site 
clearance activity sound sources. Because seals would be more widely 
dispersed while in open water, NMFS presumes that animal densities 
would be less than when seals are concentrated on and near the ice. 
Compounding that error, SOI calculated the maximum density for seals as 
4 times the average density, which NMFS does not believe is supported 
by the best available science.
    The estimates for marine mammal ``exposure'' are based on a 
consideration of the number of marine mammals that might be appreciably 
disturbed during approximately 7974 km (4955 mi) of full 3D seismic 
surveys and approximately 4294 km (2668 mi) of mitigation gun activity 
in the Chukchi Sea and by approximately 4784 km (2973 mi) of full 3D 
seismic surveys and approximately 2576 km (1600 mi) of mitigation gun 
(a single small airgun used when the airgun array is not active to 
alert marine mammals to the presence of the survey vessel) activity in 
the Beaufort Sea. In addition to the 3D seismic program, the shallow 
hazards surveys using a 2 10 in\3\ airgun array will be performed along 
approximately 1237 km (769 mi) in the Beaufort Sea and approximately 
432 km (268 mi) in the Chukchi Sea.
    NMFS further notes that the close spacing of neighboring tracklines 
within the planned 3D seismic survey areas results in a limited amount 
of total area of the Chukchi and Beaufort seas being exposed to sounds 
[gteqt] 160 dB while much of the survey area is exposed repeatedly. 
This means that the number of non-migratory cetaceans and pinnipeds 
exposed to seismic sounds would be less than if the seismic vessel 
conducted straight line transects of the sea without turning and 
returning on a nearby, parallel track. However, these animals may be 
exposed several times before the seismic vessel moves to a new site. In 
that regard, NMFS notes that the methodology used by SOI in its 
``exposure'' calculations is more valid for seismic surveys that 
transect long distances, for those surveys that ``mow the lawn'' (that 
is, remain within a relatively small area, transiting back and forth 
while shooting seismic). In such situations, the Level B harassment 
numbers tend to be highly inflated, if each ``exposure'' is calculated 
to be a different animal and not, as here, a relatively small number of 
animals residing in the area and being ``exposed'' to seismic sounds 
several times during the season. As a result, NMFS believes that SOI's 
estimated number of individual exposures does not account for multiple 
exposures of the same animal (principally non-migratory pinnipeds) 
instead of single animal exposures as the survey conducts a number of 
parallel transects of the same area (sometimes called bostrophodontical 
surveys) and the fact that the mitigation procedures would serve to 
reduce exposures to affected marine mammals.
    As mentioned previously, 3D seismic airgun arrays are composed of 
identically tuned Bolt-gun sub-arrays operating at 2,000 psi. In 
general, the signature produced by an array composed of multiple sub-
arrays has the same shape as that produced by a single sub-array while 
the overall acoustic output of the array is determined by the number of 
sub-arrays employed. The gun arrangement for the 1,049 square inches 
(in2) sub-array is detailed below and is comprised of three subarrays 
comprising a total 3,147 in2 sound source. The anticipated radii of 
influence of the bathymetric sonars and pinger are less than those for 
the air gun configurations described in Attachment A in SOI's IHA 
application. It is assumed that, during simultaneous operations of 
those additional sound sources and the air gun(s), any marine mammals 
close enough to be affected by the sonars or pinger would already be 
affected by the air gun(s). In this event, SOI believes that marine 
mammals are not expected to exhibit more than short-term and 
inconsequential responses, and such responses have not been

[[Page 36051]]

considered to constitute ``taking'' therefore, potential taking 
estimates only include noise disturbance from the use of air guns. The 
specifications of the equipment, including site clearance activities, 
to be used and areas of ensonification are described more fully in 
SOI's IHA application (see Attachment B in SOI's IHA application).

Cetaceans

    For belugas and gray whales, in both the Beaufort and Chukchi Seas 
and bowhead whales in the Chukchi Sea, Moore et al. (2000b and c) offer 
the most current data to estimate densities during summer. Density 
estimates for bowhead whales in the Beaufort Sea were updated by 
information provided by Miller et al. (2002).
    Tables 6-1 and 6-2 (Chukchi Sea) and Tables 6-3 and 6-4 (beluga and 
bowhead: Beaufort Sea) provide density estimates for the summer and 
fall, respectively. Table 6-5 provides a summary of the expected 
densities for cetaceans (other than bowheads and belugas) and pinnipeds 
during all seasons in the Beaufort Sea. The number of different 
individuals of each species potentially exposed to received levels 
[gteqt]160 dB re 1 [mu]Pa (rms) within each survey region, time period, 
and habitat zone was estimated by multiplying the expected species 
density, by the anticipated area to be ensonified to the 160-dB level 
in the survey region, time period, and habitat zone to which that 
density applies.
    The numbers of ``exposures'' were then summed by SOI for each 
species across the survey regions, seasons, and habitat zones. Some of 
the animals estimated to be exposed, particularly migrating bowhead 
whales, might show avoidance reactions before being exposed to 
[gteqt]160 dB re 1 [mu]Pa (rms). Thus, these calculations actually 
estimate the number of individuals potentially exposed to [gteqt]160 dB 
that would occur if there were no avoidance of the area ensonified to 
that level.
    For the full-3D airgun array, the cross track distance is 2 the 
160-dB radius which was measured in 2007 as 8.1 km (5.0 mi) in the 
Chukchi Sea and 13.4 km (8.3 mi) in the Beaufort Sea. The mitigation 
gun' 160-dB radius was measured at 1370 m (4495 ft) in the Chukchi Sea 
and Beaufort seas. For shallow hazards surveys to be performed by the 
Henry Christofferson, the 160-dB radius measured in 2007 was equal to 
621 m (2037 ft). Using these distances, SOI estimates that the area 
ensonified in the Chukchi Sea is approximately 15,000 km\2\ and 
approximately 10,100 km\2\ in the Beaufort Sea.
    The estimated numbers of potential marine mammal ``exposures'' by 
SOI's surveys are presented in Tables 6-6 for the summer/fall period in 
the Chukchi Sea, Table 6-7 for bowhead and beluga whales in the U.S. 
Beaufort Sea and in Table 6-8 for marine mammals (other than bowheads 
and belugas) in the Beaufort Sea. Table 1 in this document (Table 6-9 
in the IHA application) summarizes these exposure estimates based on 
the 160-dB re 1 [mu]Pa (rms) criteria for cetaceans exposed to impulse 
sounds (such as seismic).
    SOI's estimates show that the bowhead whale is the only endangered 
marine mammal expected to be exposed to noise levels [gteqt] 160 dB 
unless, as expected during the fall migratory period, bowheads avoid 
the approaching survey vessel before the received levels reach 160 dB. 
Migrating bowheads are likely to take avoidance measures, though many 
of the bowheads engaged in other activities, particularly feeding and 
socializing, probably will not. SOI's estimate of the number of bowhead 
whales potentially exposed to [gteqt]160 dB is 1540 animals (9 in the 
Chukchi Sea and 1531 in the Beaufort Sea (see Table 1)). Two other 
endangered cetacean species that may be encountered in the northern 
Chukchi/western Beaufort Sea area, the fin whale and humpback whale, 
are estimated by SOI to have two exposures each in the Chukchi Sea. 
However, NMFS believes that at least for the fin whale, no animals 
would be so exposed given their low ``average'' estimates of densities 
in the area.
    Most of the cetaceans exposed to seismic sounds with received 
levels [gteqt]160 dB would involve bowhead, gray, and beluga whales, 
and the harbor porpoise. Average estimates of the number of exposures 
of cetaceans by 3D seismic surveys (other than bowheads), in descending 
order, are beluga (298), gray whale (183), and harbor porpoise (58). 
The regional breakdown of these numbers is shown in Tables 6-6 to 6-8. 
Estimates for other species are lower (Table 6-9). These estimates are 
also provided in Table 1 in this Federal Register notice.

Pinnipeds

    Ringed, spotted, and bearded seals are all associated with sea ice, 
and most census methods used to determine density estimates for 
pinnipeds are associated with counting the number of seals hauled out 
on ice. Correction factors have been developed for most pinniped 
species that address biases associated with detectability and 
availability of a particular species. Although extensive surveys of 
ringed and bearded seals have been conducted in the Beaufort Sea, the 
majority of the surveys have been conducted over the landfast ice and 
few seal surveys have been in open water. The most comprehensive survey 
data set on ringed seals (and bearded seal) from the central and 
eastern Beaufort Sea was conducted on offshore pack ice in late spring 
(Kingsley, 1986). It is important to note that all proposed activities 
will be conducted during the open-water season and density estimates 
used here were based on counts of seals on ice. Therefore, densities 
and potential take numbers will overestimate the numbers of seals that 
would likely be encountered and/or exposed because only the animals in 
the water would be exposed to the seismic and clearance activity sound 
sources.
    The ringed seal is the most widespread and abundant pinniped in 
ice-covered arctic waters and ringed seals are expected to account for 
the vast majority of marine mammals expected to be encountered, and 
hence exposed to airgun sounds with received levels [gteqt]160 dB re 1 
[mu]Pa (rms) during SOI's seismic survey. The average estimate is that 
13,256 ringed seals might be exposed to seismic sounds with received 
levels [gteqt]160 dB. Two additional pinniped species (other than the 
Pacific walrus) are expected to be encountered. They are the bearded 
seal (592 exposures), and the spotted seal (422 exposures)(see Table 1 
in this document or Table 6-9 in the IHA application). The spotted seal 
and ribbon seal are unlikely to be encountered during SOI's seismic 
surveys.

[[Page 36052]]



  TABLE 1. Summary of the Number of Potential Exposures of Marine Mammals to Received Sound Levels in the Water of [gteqt]160 dB During SOI's Proposed
  Seismic Program in the Chukchi Sea and Beaufort Sea, Alaska, July - November, 2008. Not all marine mammals will change their behavior when exposed to
                         these sound levels, although some might alter their behavior somewhat when levels are lower (see text).
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                                                Number of Individuals Exposed to Sound Levels [gteqt]160dB
                                 -----------------------------------------------------------------------------------------------------------------------
             Species                            Chukchi Sea                            Beaufort Sea                                Total
                                 -----------------------------------------------------------------------------------------------------------------------
                                         Avg.                Max.                Avg.                Max.                Avg.                Max.
--------------------------------------------------------------------------------------------------------------------------------------------------------
Odontocetes
  Monodontidae
    Beluga                        63                  254                 234                 938                 298                 1192
    Narwhal                       0                   0                   0                   0                   0                   0
  Delphinidae
    Killer whale                  2                   6                   0                   0                   2                   6
  Phocoenidae
    Harbor porpoise               57                  227                 2                   6                   58                  234
Mysticetes
    Bowhead Whale \a\             9                   46                  1531                1536                1540                1582
    Fin whale                     2                   6                   0                   0                   2                   6
    Gray whale                    182                 727                 2                   6                   183                 734
    Humpback whale                2                   6                   0                   0                   2                   6
    Minke whale                   2                   6                   0                   0                   2                   6
                                 -----------------------------------------------------------------------------------------------------------------------
    Total Cetaceans               70                  281                 1533                1543                1603                1824
Pinnipeds
    Bearded seal                  270                 405                 322                 1286                592                 1691
    Ribbon seal                   2                   6                   0                   0                   2                   6
    Ringed seal                   6951                10827               6305                25221               13256               36047
    Spotted seal                  361                 562                 61                  243                 422                 804
                                 -----------------------------------------------------------------------------------------------------------------------
    Total Pinnipeds               5678                8836                6687                26750               12366               35586
--------------------------------------------------------------------------------------------------------------------------------------------------------
\a\ See text for description of bowhead whale estimate for the Beaufort Sea

Potential Marine Mammal Disturbance At Less Than 160 dB Received Levels

    During autumn seismic surveys in the Beaufort Sea, migrating 
bowhead whales displayed avoidance (i.e., deflection) at distances out 
to 20-30 km (12-19 mi) and received sound levels of ~130 dB (rms) 
(Miller et al., 1999; Richardson et al., 1999). Therefore, it is 
possible that a larger number of bowhead whales than estimated above 
may be disturbed to some extent if reactions occur at [gteqt]130 dB 
(rms).
    However, these references note that bowhead whales below the water 
surface at a distance of 20 km (12.4 mi) from an airgun array received 
pulses of about 117-135 dB re 1 [mu]Pa rms, depending upon propagation. 
Corresponding levels at 30 km (18.6 mi) were about 107-126 dB re 1 
[mu]Parms. Miller et al. (1999) surmise that deflection may have begun 
about 35 km (21.7 mi) to the east of the seismic operations, but did 
not provide SPL measurements to that distance, and noted that sound 
propagation has not been studied as extensively eastward in the 
alongshore direction, as it has northward, in the offshore direction. 
Therefore, while this single year of data analysis indicates that 
bowhead whales may make minor deflections in swimming direction at a 
distance of 30-35 km (18.6-21.7 mi), there is no indication that the 
sound pressure level (SPL) where deflection first begins is at 120 dB- 
it could be at another SPL lower or higher than 120 dB. Miller et al. 
(1999) also note that the received levels at 20-30 km (12.4-18.6 mi) 
were considerably lower in 1998 than have previously been shown to 
elicit avoidance in bowheads exposed to seismic pulses. However, the 
seismic airgun array used in 1998 was larger than the ones used in 1996 
and 1997. Therefore, NMFS believes that it cannot scientifically 
support adopting any single SPL value below 160 dB and apply it across 
the board for all species and in all circumstances.
    Second, NMFS has noted in the past that minor course changes during 
migration are not considered a significant behavioral change and, as 
indicated in MMS' 2006 Final PEA, have not been seen at other times of 
the year and during other activities. To show the contextual nature of 
this minor behavioral modification, recent monitoring studies of 
Canadian seismic operations indicate that when not migrating but 
involved in feeding, bowhead whales do not move away from a noise 
source at an SPL of 160 dB. Therefore, while bowheads may avoid an area 
of 20 km (12.4 mi) around a noise source, when such a determination 
requires a post-survey computer analysis to find that bowheads have 
made slight course change, NMFS believes that this does not rise to a 
level considered to be a significant behavioral response on the part of 
the marine mammals or under the MMPA, a ``take.'' NMFS therefore 
continues to estimate ``takings'' under the MMPA from impulse noises, 
such as seismic, as being at a distance of 160 dB (re 1 [mu]Pa). NMFS 
needs to point out however, that while this might not be a ``taking'' 
in the sense that there is not a significant behavioral response by 
bowhead whales, a minor course deflection by bowheads can have a 
significant impact on the subsistence uses of bowheads. As a result, 
NMFS still requires mitigation measures to ensure that the activity 
does not have an unmitigable adverse impact on subsistence uses of 
bowheads.
    Finally, it is likely that SOI will not conduct seismic operations 
in the Beaufort Sea during that part of the fall bowhead migration that 
occurs at the same time as the fall bowhead subsistence hunt. As a 
result, a large proportion of the bowhead population would migrate past 
the Beaufort Sea

[[Page 36053]]

seismic survey area without being exposed to any seismic sounds. 
Limiting operations during the fall bowhead whale migration is also 
meant to reduce any chance of conflicting with subsistence hunting and 
will continue at least until hunting quotas have been filled by the 
coastal communities.

Potential Impact on Habitat

    SOI states that the proposed seismic activities will not result in 
any permanent impact on habitats used by marine mammals, or to their 
prey sources. Seismic activities will mostly occur during the time of 
year when bowhead whales are widely distributed and would be expected 
to occur in very low numbers within the seismic activity area (mid- to 
late-July through September). Any effects would be temporary and of 
short duration at any one place. The primary potential impacts to 
marine mammals is associated with elevated sound levels from the 
proposed airguns were discussed previously in this document.
    A broad discussion on the various types of potential effects of 
exposure to seismic on fish and invertebrates can be found in the NMFS/
MMS Draft PEIS for Arctic Seismic Surveys (see ADDRESSES).
    Mortality to fish, fish eggs and larvae from seismic energy sources 
would be expected within a few meters (0.5 to 3 m (1.6 to 9.8 ft)) from 
the seismic source. Direct mortality has been observed in cod and 
plaice within 48 hours that were subjected to seismic pulses two meters 
from the source (Matishov, 1992), however other studies did not report 
any fish kills from seismic source exposure (La Bella et al., 1996; 
IMG, 2002; Hassel et al., 2003). To date, fish mortalities associated 
with normal seismic operations are thought to be slight. Saetre and Ona 
(1996) modeled a worst-case mathematical approach on the effects of 
seismic energy on fish eggs and larvae, and concluded that mortality 
rates caused by exposure to seismic are so low compared to natural 
mortality that issues relating to stock recruitment should be regarded 
as insignificant.
    Limited studies on physiological effects on marine fish and 
invertebrates to acoustic stress have been conducted. No significant 
increases in physiological stress from seismic energy were detected for 
various fish, squid, and cuttlefish (McCauley et al., 2000) or in male 
snow crabs (Christian et al., 2003). Behavioral changes in fish 
associated with seismic exposures are expected to be minor at best. 
Because only a small portion of the available foraging habitat would be 
subjected to seismic pulses at a given time, fish would be expected to 
return to the area of disturbance anywhere from 15-30 minutes (McCauley 
et al., 2000) to several days (Engas et al., 1996).
    Available data indicates that mortality and behavioral changes do 
occur within very close range to the seismic source, however, the 
proposed seismic acquisition activities in the Chukchi and Beaufort 
seas are predicted by SOI to have a negligible effect to the prey 
resource of the various life stages of fish and invertebrates available 
to marine mammals occurring during the project's duration. In addition, 
it is unlikely that bowheads, gray, or beluga whales will be excluded 
from any habitat.

Effects of Seismic Noise and Other Related Activities on Subsistence

    The disturbance and potential displacement of marine mammals by 
sounds from seismic activities are the principal concerns related to 
subsistence use within the Beaufort and Chukchi seas. The harvest of 
marine mammals (mainly bowhead whales, but also ringed and bearded 
seals) is central to the culture and subsistence economies of the 
coastal North Slope and Western Alaskan communities. In particular, if 
fall-migrating bowhead whales are displaced farther offshore by 
elevated noise levels, the harvest of these whales could be more 
difficult and dangerous for hunters. The impact would be that whaling 
crews would necessarily be forced to travel greater distances to 
intercept westward migrating whales thereby creating a safety hazard 
for whaling crews and/or limiting chances of successfully striking and 
landing bowheads. The harvest could also be affected if bowheads become 
more skittish when exposed to seismic noise. Hunters relate how bowhead 
whales also appear ``angry'' due to seismic noise, making whaling more 
dangerous.
    This potential impact on subsistence uses of marine mammals is 
proposed by SOI to be mitigated by application of the procedures 
established in a Conflict Avoidance Agreement (CAA) between the seismic 
operators and the AEWC and the Whaling Captains' Associations of 
Kaktovik, Nuiqsut, Barrow, Pt. Hope and Wainwright. SOI notes that the 
times and locations of seismic and other noise producing sources are 
likely to be curtailed during times of active bowhead whale scouting 
and actual whaling activities within the traditional subsistence 
hunting areas of the potentially affected communities. (See Mitigation 
for Subsistence). SOI states that seismic survey activities will also 
be scheduled to avoid the traditional subsistence beluga hunt which 
annually occurs in July in the community of Pt. Lay. As a result, SOI 
believes that there should be no adverse impacts on the availability of 
whale species for subsistence uses. In the event that a CAA is not 
signed by either party, then NMFS will implement mitigation measures it 
determines are necessary to ensure that the taking of marine mammals by 
SOI's seismic and related activities do not have an unmitigable adverse 
impact on the subsistence uses of marine mammals.
    In the Chukchi Sea, SOI's seismic work should not have unmitigable 
adverse impacts on the availability of the whale species for 
subsistence uses. The whale species normally taken by Inupiat hunters 
are the bowhead and belugas. SOI's Chukchi Sea seismic operations will 
not begin until after July 20, 2008 by which time the majority of 
bowheads will have migrated to their summer feeding areas in Canada. 
Even if any bowheads remain in the northeastern Chukchi Sea after July 
20, they are not normally hunted after this date until the return 
migration occurs around late September when a fall hunt by Barrow 
whalers takes place. In recent years, bowhead whales have occasionally 
been taken in the fall by coastal villages along the Chukchi coast, but 
the total number of these animals has been small. Seismic operations 
for the Chukchi Sea seismic program will be timed and located so as to 
avoid any possible conflict with the Barrow fall whaling, and specific 
provisions governing the timing and location are expected to be 
incorporated, if signed, into a CAA established between SOI and 
WesternGeco, the AEWC, and the Whaling Captains Associations.
    Beluga whales may also be taken sporadically for subsistence needs 
by coastal villages, but traditionally are taken in small numbers very 
near the coast. However, SOI will establish ``communication stations'' 
in the villages to monitor impacts. Gray whales, which will be abundant 
in the northern Chukchi Sea from spring through autumn, are not taken 
by subsistence hunters.

Plan of Cooperation (POC)

    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 
activities that take place in Arctic waters to provide a POC 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. SOI has summarized concerns received 
during 2006 and 2007 into the 2007 POC, which was submitted during June 
2007 to federal agencies as well as to

[[Page 36054]]

subsistence stakeholders, and updated in July 2007 and earlier this 
year. SOI has developed the POC to mitigate and avoid any unreasonable 
interference by SOI's planned activities on North Slope subsistence 
uses and resources. The POC is the result of numerous meetings and 
consultations between SOI, affected subsistence communities and 
stakeholders, and federal agencies beginning in October 2006 (see Table 
12-1 in SOI's IHA application for a list of meetings). The POC 
identifies and documents potential conflicts and associated measures 
that will be taken to minimize any adverse effects on the availability 
of marine mammals for subsistence use. To be effective, SOI believes 
the POC must be a dynamic document which will expand to incorporate the 
communications and consultation that will continue to occur throughout 
2008. Outcomes of POC meetings are included in quarterly updates 
attached to the POC and distributed to federal, state, and local 
agencies as well as local stakeholder groups.
    SOI hopes that a CAA will result from the POC meetings. In that 
regard, the AEWC submitted a draft CAA to the industry earlier this 
spring. If signed, the CAA will incorporate all appropriate measures 
and procedures regarding the timing and areas of the operator's planned 
activities (e.g., times and places where seismic operations will be 
curtailed or moved in order to avoid potential conflicts with active 
subsistence whaling and sealing); a communications system between 
operator's vessels and whaling and hunting crews (i.e., the 
communications center will be located in strategic areas); provision 
for marine mammal observers/Inupiat communicators aboard all project 
vessels; conflict resolution procedures; and provisions for rendering 
emergency assistance to subsistence hunting crews. If requested, post-
season meetings will also be held to assess the effectiveness of a 2008 
CAA between SOI, the AEWC, and the Whaling Captains Associations, to 
address how well conflicts (if any) were resolved; and to receive 
recommendations on any changes (if any) might be needed in the 
implementation of future CAAs.
    It should be noted that NMFS is required by the MMPA to make a 
determination that an activity would not have an unmitigable adverse 
impact on the subsistence needs for marine mammals. While this includes 
usage of both cetaceans and pinnipeds, the primary impact from seismic 
activities is expected to be impacts from noise on bowhead whales 
during its westward fall migration and feeding period in the Beaufort 
Sea. NMFS has defined unmitigable adverse impact 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 (50 CFR 216.103).
    Therefore, while a signed CAA allows NMFS to make a determination 
that the activity will not have an unmitigable adverse impact on the 
subsistence use of marine mammals, if one or both parties fail to sign 
the CAA, then NMFS will make the determination that the activity will 
or will not have an unmitigable adverse impact on subsistence use of 
marine mammals. This determination may require that the IHA contain 
additional mitigation measures in order for this decision to be made.

Mitigation and Monitoring

    As part of its application, SOI has proposed implementing a marine 
mammal mitigation and monitoring program (4MP) that will consist of 
monitoring and mitigation during SOI's seismic and shallow-hazard 
survey activities. In conjunction with monitoring during SOI's 
exploratory drilling program (subject to a separate notice and review), 
monitoring will provide information on the numbers of marine mammals 
potentially affected by these activities and permit real time 
mitigation to prevent injury of marine mammals by industrial sounds or 
activities. These goals will be accomplished by conducting vessel-, 
aerial-, and acoustic-monitoring programs to characterize the sounds 
produced by the seismic airgun arrays and related equipment and to 
document the potential reactions of marine mammals in the area to those 
sounds and activities. Acoustic modeling will be used to predict the 
sound levels produced by the seismic, shallow hazards and drilling 
equipment in the U.S. Beaufort and Chukchi seas. For the seismic 
program, acoustic measurements will also be made to establish zones of 
influence (ZOIs) around the activities that will be monitored by 
observers. Aerial monitoring and reconnaissance of marine mammals and 
recordings of ambient sound levels, vocalizations of marine mammals, 
and received levels should they be detectable using bottom-founded 
acoustic recorders along the Beaufort Sea coast will be used to 
interpret the reactions of marine mammals exposed to the activities. 
The components of SOI's mitigation and monitoring programs are briefly 
described next. Additional information can be found in SOI's 
application.

Proposed Mitigation Measures

    As part of its IHA application, SOI submitted its proposed 
mitigation and monitoring program for SOI's seismic programs in the 
Chukchi and Beaufort seas for 2008/2009. SOI notes that the proposed 
seismic exploration program incorporates both design features and 
operational procedures for minimizing potential impacts on cetaceans 
and pinnipeds and on subsistence hunts. Seismic survey design features 
include: (1) Timing and locating seismic activities to avoid 
interference with the annual fall bowhead whale hunts; (2) configuring 
the airgun arrays to maximize the proportion of energy that propagates 
downward and minimizes horizontal propagation; (3) limiting the size of 
the seismic energy source to only that required to meet the technical 
objectives of the seismic survey; and (4) conducting pre-season 
modeling and early season field assessments to establish and refine (as 
necessary) the appropriate 180 dB and 190 dB safety zones, and other 
radii relevant to behavioral disturbance.
    The potential disturbance of cetaceans and pinnipeds during seismic 
operations will be minimized further through the implementation of the 
following several ship-based mitigation measures.
Safety and Disturbance Zones
    Safety radii for marine mammals around airgun arrays are 
customarily defined as the distances within which received pulse levels 
are greater than or equal to 180 dB re 1 [mu]Pa (rms) for cetaceans and 
greater than or equal to 190 dB re 1 [mu]Pa (rms) for pinnipeds. These 
safety criteria are based on an assumption that seismic pulses at lower 
received levels will not injure these animals or impair their hearing 
abilities, but that higher received levels might result in such 
effects. It should be understood that marine mammals inside these 
safety zones will not necessarily be seriously injured or killed as 
these zones were established prior to the current understanding that 
significantly higher levels of impulse sounds would be required before 
injury or mortality would occur. This has been described previously in 
this document.

[[Page 36055]]

    SOI anticipates that monitoring similar to that conducted in the 
Chukchi Sea in 2007 will also be required in the Chukchi and the 
Beaufort seas in 2008. SOI plans to use marine mammal observers (MMOs) 
onboard the seismic vessel to monitor the 190- and 180-dB (rms) safety 
radii for pinnipeds and cetaceans, respectively and to implement 
appropriate mitigation as discussed in the proceeding sections. SOI 
also plans to monitor the 160-dB (rms) disturbance zone with MMOs 
onboard the chase vessels in 2008 as was done in 2006 and 2007. There 
has also been concern that received pulse levels as low as 120 dB (rms) 
may have the potential to disturb some whales. In 2006 and 2007, there 
was a requirement in the IHAs issued to SOI by NMFS to implement 
special mitigation measures if specified numbers of bowhead cow/calf 
pairs might be exposed to seismic sounds greater than 120 dB rms or if 
large groups (greater than 12 individuals) of bowhead or gray whales 
might be exposed to sounds greater than or equal to 160 dB rms. In 
2007, monitoring of the 120-dB (rms) zone was required in the Beaufort 
Sea after 25 September. For 2008, SOI anticipates that it will not 
operate in the Chukchi Sea between September 25th and the time ice 
prevents additional work in the Beaufort Sea, by which time NMFS 
believes the bowhead whale cow/calf migration period to have been 
completed. As a result, it is unlikely that SOI will not need to 
monitor the 120 dB (rms) zone in the Chukchi Sea in 2008.
    During the 2006 and 2007 seismic programs in the Chukchi and 
Beaufort Seas, SOI utilized a combination of pre-season modeling and 
early season sound source verification to establish safety zones for 
these sound level criteria. As the equipment being utilized in 2008 is 
the same as that used in the 2006 and 2007 field seasons, and the 
majority of locations where seismic data is to be acquired were modeled 
prior to the 2006 and 2007 seasons, SOI will initially utilize the 
derived (measured) sound criterion distances from 2006. Any locations 
not modeled previously will be modeled prior to 2008 survey initiation 
and mitigation distances and safety zones adjusted up, if necessary 
following sound measurements at the new locations. Modeling of the 
sound propagation is based on the size and configuration of the airgun 
array and on available oceanographic data. An acoustics contractor will 
perform the direct measurements of the received levels of underwater 
sound versus distance and direction from the airgun arrays using 
calibrated hydrophones. The acoustic data will be analyzed as quickly 
as reasonably practicable in the field and used to verify (and if 
necessary adjust) the safety distances. The mitigation measures to be 
implemented will include ramp ups, power downs, and shut downs as 
described next.
Ramp-Up
    A ramp up of an airgun array provides a gradual increase in sound 
levels, and involves a step-wise increase in the number and total 
volume of airguns firing until the full volume is achieved. The purpose 
of a ramp up (or ``soft start'') is to ``warn'' cetaceans and pinnipeds 
in the vicinity of the airguns and to provide the time for them to 
leave the area and thus avoid any potential injury or impairment of 
their hearing abilities. During the proposed seismic program, the 
seismic operator will ramp up the airgun arrays slowly, at a rate no 
greater than 6 dB/5 minute period. Full ramp ups (i.e., from a cold 
start after a shut down, when no airguns have been firing) will begin 
by firing a small airgun in the arrays. The minimum duration of a shut-
down period, i.e., without air guns firing, which must be followed by a 
ramp up typically is the amount of time it would take the source vessel 
to cover the 180-dB safety radius. That depends on ship speed and the 
size of the 180-dB safety radius, which are not known at this time.
    A full ramp up, after a shut down, will not begin until there has 
been a minimum of a 30-minute period of observation by MMOs of the 
safety zone to assure that no marine mammals are present. The entire 
safety zone must be visible during the 30-minute leading up to a full 
ramp up. If the entire safety zone is not visible, then ramp up from a 
cold start cannot begin. If a marine mammal(s) is sighted within the 
safety zone during the 30-minute watch prior to ramp up, ramp up will 
be delayed until the marine mammal(s) is sighted outside of the safety 
zone or the animal(s) is not sighted for at least 15-30 minutes: 15 
minutes for small odontocetes and pinnipeds, or 30 minutes for baleen 
whales and large odontocetes.
    During periods of turn around and transit between seismic 
transects, at least one airgun will remain operational to alert marine 
mammals in the area of the vessel's location. The ramp-up procedure 
still will be followed when increasing the source levels from one air 
gun to the full arrays. Moreover, keeping one air gun firing will avoid 
the prohibition of a cold start during darkness or other periods of 
poor visibility. Through use of this approach, seismic operations can 
resume upon entry to a new transect without a full ramp up and the 
associated 30-minute lead-in observations. MMOs will be on duty 
whenever the airguns are firing during daylight, and during the 30-min 
periods prior to ramp-ups as well as during ramp-ups. Daylight will 
occur for 24 hr/day until mid-August, so until that date MMOs will 
automatically be observing during the 30-minute period preceding a ramp 
up. Later in the season, MMOs will be called out at night to observe 
prior to and during any ramp up. The seismic operator and MMOs will 
maintain records of the times when ramp-ups start, and when the airgun 
arrays reach full power.
Power Downs and Shut Downs
    A power down is the immediate reduction in the number of operating 
airguns from all guns firing to some smaller number. A shut down is the 
immediate cessation of firing of all airguns. The airgun arrays will be 
immediately powered down whenever a marine mammal is sighted 
approaching close to or within the applicable safety zone of the full 
airgun arrays (i.e., 180 dB rms for cetaceans, 190 dB rms for 
pinnipeds), but is outside the applicable safety zone of the single 
airgun. If a marine mammal is sighted within the applicable safety zone 
of the single airgun, the airgun array will be shut down (i.e., no 
airguns firing). Although observers will be located on the bridge ahead 
of the center of the airgun array, the shutdown criterion for animals 
ahead of the vessel will be based on the distance from the bridge 
(vantage point for MMOs) rather than from the airgun array - a 
precautionary approach. For marine mammals sighted alongside or behind 
the airgun array, the distance is measured from the array.
Operations at Night and in Poor Visibility
    When operating under conditions of reduced visibility attributable 
to darkness or to adverse weather conditions, infra-red or night-vision 
binoculars will be available for use. However, it is recognized that 
their effectiveness is limited. For that reason, MMOs will not 
routinely be on watch at night, except in periods before and during 
ramp-ups. It should be noted that if one small airgun remains firing, 
the rest of the array can be ramped up during darkness or in periods of 
low visibility. Seismic operations may continue under conditions of 
darkness or reduced visibility.

[[Page 36056]]

Preliminary Mitigation Determination

    As NMFS believes that the combination of use of the mitigation gun, 
ramp-up of the seismic airgun array and the slow vessel speed (to allow 
marine mammals sufficient time to take necessary avoidance measures), 
the use of trained marine mammal observers and shut-down procedures (to 
avoid potential injury if the animal is close to the vessel), and the 
behavioral response of marine mammals (especially bowhead whales) to 
avoid areas of high anthropogenic noise all provide protection to 
marine mammals from serious injury or mortality. As a result, NMFS 
believes that it is not necessary to require termination of survey 
activities during darkness or reduced visibility and that the current 
level of mitigation will result in the lowest level of impact on marine 
mammals practicable.

Proposed Marine Mammal Monitoring

    SOI has proposed to implement a marine mammal monitoring program 
(4MP) to collect data to address the following specific objectives: (1) 
improve the understanding of the distribution and abundance of marine 
mammals in the Chukchi and Beaufort sea project areas; (2) understand 
the propagation and attenuation of anthropogenic sounds in the waters 
of the project areas; (3) determine the ambient sound levels in the 
waters of the project areas; and (4) assess the effects of sound on 
marine mammals inhabiting the project areas and their distribution 
relative to the local people that depend on them for subsistence 
hunting.
    These objectives and the monitoring and mitigation goals will be 
addressed by: (1) vessel-based MMOs on the seismic source and other 
support vessels; (2) an acoustic program to predict and then measure 
the sounds produced by the seismic operations and the possible 
responses of marine mammals to those sounds; (3) an aerial monitoring 
and reconnaissance of marine mammals available for subsistence harvest 
along the Chukchi Sea coast; and (4) bottom-founded autonomous acoustic 
recorder arrays along the Alaskan coast and offshore in the Chukchi and 
Beaufort seas to record ambient sound levels, vocalizations of marine 
mammals, and received levels of seismic operations should they be 
detectable.

Seismic Source Vessel-based Visual Monitoring

    A sufficient number of MMOs will be required to be onboard the 
seismic source vessel to meet the following criteria: (1) 100 percent 
monitoring coverage during all periods of seismic operations in 
daylight and for the 30 minutes prior to starting ramp-up and for the 
number of minutes required to reach full ramp-up; (2) coverage during 
darkness for 30-minutes before and during ramp-ups (provided MMOs 
verify that they can clearly see the entire safety zone); (3) maximum 
of 4 consecutive hours on watch per MMO; (4) maximum of approximately 
12 hours on watch per day per MMO with no other shipboard duties; and 
(5) two-MMO coverage during ramp-up and the 30 minutes prior to full 
ramp-ups and for as large a fraction of the other operating hours as 
possible.
    To accomplish these tasks SOI proposes to have from three to five 
MMOs (including one Inupiat observer/communicator) based aboard the 
seismic vessel. However, NMFS does not consider Inupiat observers to be 
included in the required minimum number of MMOs unless they have 
undergone MMO training at a facility approved in advance by NMFS. MMOs 
will search for and observe marine mammals whenever seismic operations 
are in progress and for at least 30 minutes before the planned start of 
seismic transmissions or whenever the seismic array's operations have 
been suspended for more than 10 minutes. The MMOs will scan the area 
immediately around the vessels with reticle binoculars during the 
daytime. Laser rangefinding equipment will be available to assist with 
distance estimation. After mid-August, when the duration of darkness 
increases, image intensifiers will be used by observers and additional 
light sources may be used to illuminate the safety zone.
    The seismic vessel-based work will provide the basis for real-time 
mitigation (airgun power downs and, as necessary, shut downs), as 
called for by the IHAs; information needed to estimate the ``take'' of 
marine mammals by harassment, which must be reported to NMFS; data on 
the occurrence, distribution, and activities of marine mammals in the 
areas where the seismic program is conducted; information to compare 
the distances, distributions, behavior; movements of marine mammals 
relative to the source vessels at times with and without seismic 
activity; a communication channel to Inupiat whalers through the 
Communications Coordination Center in coastal villages; and continued 
employment and capacity building for local residents, with one 
objective being to develop a larger pool of experienced Inupiat MMOs.
    The use of four or more MMOs allows two observers to be on duty 
simultaneously for up to 50 percent of the active airgun hours. The use 
of two observers increases the probability of detecting marine mammals, 
and two observers will be on duty for the entire duration of time 
whenever the seismic array is ramped up. As mentioned previously, 
individual watches will be limited to no more than 4 consecutive hours 
to avoid observer fatigue (and no more than 12 hours on watch per 24 
hour day). When mammals are detected within or about to enter the 
safety zone designated to prevent injury to the animals (see 
Mitigation), the geophysical crew leader will be notified so that 
shutdown procedures can be implemented immediately. Details of the 
vessel-based marine mammal monitoring program are described in SOI's 
IHA application (see Appendix B).

Chase Boat Monitoring

    MMOs will also be present on smaller support vessels that travel 
with the seismic source vessel. These support vessels are commonly 
known as ``guard boats'' or ``chase boats.'' During seismic operations, 
a chase boat remains very near to the stern of the source vessel 
anytime that a member of the source vessel crew is on the back deck 
deploying or retrieving equipment related to the seismic array. Once 
the seismic array is deployed the chase boat then serves to keep other 
vessels away from the seismic source vessel and the seismic array 
itself (including hydrophone streamer) during production of seismic 
data and provide additional emergency response capabilities.
    In the Chukchi and Beaufort seas in 2008, SOI's seismic source 
vessel will have one associated chase boat and possibly an additional 
supply vessel. The chase boat and supply vessel (if present) will have 
three MMOs onboard to collect marine mammal observations and to monitor 
the 160 dB (rms) disturbance zone from the seismic airgun array. MMOs 
on the chase boats will be able to contact the seismic ship if marine 
mammals are sited. To maximize the amount of time during the day that 
an observer is on duty, two observers aboard the chase boat or supply 
vessel will rarely work at the same time. As on the source vessels, 
shifts will be limited to 4 hrs in length and 12 hrs total in a 24 hr 
period.
    SOI plans to monitor the 160-dB (rms) disturbance radius in 2008 
using MMOs onboard the chase vessel. The 160-dB radius in the Chukchi 
Sea in 2007 was determined by JASCO (2007) to extend ~8.1 km from the 
airgun

[[Page 36057]]

source on the M/V Gilavar. In the Beaufort Sea, the 160-dB radius was 
measured at 13.45 km (8.4 mi) (JASCO, 2007). This area around the 
seismic vessel was monitored by MMOs onboard the M/V Gulf Provider (the 
chase boat used in 2006 and 2007 operations). As in 2007 during 
monitoring of the 160-dB zone the M/V Gulf Provider will travel ~8 km 
(5 mi) ahead and to the side of the M/V Gilavar. MMOs onboard the M/V 
Gulf Provider will search the area ahead of the M/V Gilavar within the 
160-dB zone for marine mammals. Every 8 km (5 mi) or so, the M/V Gulf 
Provider will move to the other side of the M/V Gilivar continuing in a 
stair-step type pattern. The distance at which the M/V Gulf Provider 
(or other equivalent vessel) travels ahead of the M/V Gilavar will be 
determined by the measured 160-dB radius. Mitigation (i.e., power down 
or shut down of the airgun array) will be implemented if a group of 12 
or more bowhead or gray whales enter the 160-dB zone. SOI will use this 
same protocol in the Beaufort Sea after the 160-dB radius has been 
determined. Depending upon the size of the measured 160-dB zone around 
the airgun array SOI may decide to use a vessel equipped with a Passive 
Acoustic Monitoring (PAM) system (if it has been independently field 
tested and certified to NMFS as being capable of detecting marine 
mammals that inhabit the Arctic Ocean) or may use a second chase boat 
to ensure effective monitoring of the area.
    In 2007 the measured distance to the 180-dB isopleth ranged from 
about 2.45 km (1.5 mi) in the Chukchi Sea to about 2.2 km (1.4 mi) in 
the Beaufort Sea near the Sivulliq prospect. SOI decided to use an 
additional vessel to monitor this zone given its importance in 
protecting marine mammals from potential injury associated with 
exposure to seismic pulses. Depending upon the measured radius for the 
180-dB zone in 2008/2009 SOI may elect to use a PAM system to help 
monitor this area around the M/V Gilavar as well.

Aerial Survey Program

    SOI proposes to conduct an aerial survey program in support of the 
seismic exploration program in the Beaufort Sea during summer and fall 
of 2008. The objectives of the aerial survey will be: (1) to advise 
operating vessels as to the presence of marine mammals in the general 
area of operation; (2) to provide mitigation monitoring (120 dB zones) 
as may be required under the conditions of the IHA; (3) to collect and 
report data on the distribution, numbers, movement and behavior of 
marine mammals near the seismic operations with special emphasis on 
migrating bowhead whales; (4) to support regulatory reporting and 
Inupiat communications related to the estimation of impacts of seismic 
operations on marine mammals; (5) to monitor the accessibility of 
bowhead whales to Inupiat hunters and (6) to document how far west of 
seismic activities bowhead whales travel before they return to their 
normal migration paths, and if possible, to document how far east of 
seismic operations the deflection begins.
    The same aerial survey design will be implemented during the summer 
(August) and fall (late August-October) period, but during the summer, 
the survey grid will be flown twice a week, and during the fall, 
flights will be conducted daily. During the early summer, few cetaceans 
are expected to be encountered in the nearshore Alaskan Beaufort Sea 
where seismic surveys will be conducted. Those cetaceans that are 
encountered are expected to be either along the coast (gray whales: 
(Maher, 1960; Rugh and Fraker, 1981; Miller et al., 1999; Treacy, 2000) 
or seaward of the continental shelf among the pack ice (bowheads: Moore 
et al., 1989b; Miller et al., 2002; and belugas: Moore et al., 1993; 
Clark et al., 1993; Miller et al., 1999) north of the area where 
seismic surveys and drilling activities are to be conducted. During 
some years a few gray whales are found feeding in shallow nearshore 
waters from Barrow to Kaktovik but most sightings are in the western 
part of that area.
    During the late summer and fall, the bowhead whale is the primary 
species of concern, but belugas and gray whales are also present. 
Bowheads and belugas migrate through the Alaskan Beaufort Sea from 
summering areas in the central and eastern Beaufort Sea and Amundsen 
Gulf to their wintering areas in the Bering Sea (Clarke et al., 1993; 
Moore et al., 1993; Miller et al., 2002). Some bowheads are sighted in 
the eastern Alaskan Beaufort Sea starting mid-August and near Barrow 
starting late August but the main migration does not start until early 
September.
    The aerial survey procedures will be generally consistent with 
those during earlier industry studies (Miller et al., 1997, 1998, 1999; 
Patterson et al., 2007). This will facilitate comparison and pooling of 
data where appropriate. However, SOI notes that the specific survey 
grids will be tailored to SOI's operations and the time of year. 
Information on survey procedures can be found in SOI's IHA application.

Survey Design in the Beaufort Sea in Summer

    The main species of concern in the Beaufort Sea is the bowhead 
whale but small numbers of belugas, and in some years, gray whales, are 
present in the Beaufort Sea during summer (see above). Few bowhead 
whales are expected to be found in the Beaufort Sea during early 
August; however, a reduced aerial survey program is proposed during the 
summer prior to seismic operations to confirm the distribution and 
numbers of bowheads, gray whales and belugas, because no recent surveys 
have been conducted at this time of year. The few bowheads that were 
present in the Beaufort Sea during summer in the late 1980s were 
generally found among the pack ice in deep offshore waters of the 
central Beaufort Sea (Moore and DeMaster, 1998; Moore et al., 2000). 
Although gray whales were rarely sighted in the Beaufort Sea prior to 
the 1980's (Rugh and Fraker, 1981), sightings appear to have become 
more common along the coast of the Beaufort Sea in summer and early 
fall (Miller et al., 1999; Treacy 1998, 2000, 2002; Patterson et al., 
2007) possibly because of increases in the gray whale population and/or 
reductions in ice cover in recent years. Because no summer surveys have 
been conducted in the Beaufort Sea since the 1980s, the information on 
summer distribution of cetaceans will be valuable for planning future 
seismic or drilling operations. The grid that will be flown in the 
summer will be the same grid flown later in the year, but it will be 
flown twice a week instead of daily. If ceteceans are encountered in 
the vicinity of planned seismic operations, then SOI would consider 
flying the survey grid proposed for later in the season, rather than 
the early-season survey plan. Surveys will be conducted 2 days/week 
until the period one week prior to the start of seismic operations in 
the Beaufort Sea. Beginning approximately one week prior to the start 
of seismic operations, daily surveys would be initiated and they would 
be conducted using the grid shown in Figure 3 in Appendix B of SOI's 
IHA application.

Survey Design in the Beaufort Sea in Fall

    Aerial surveys during the late August-October period will be 
designed to provide mitigation monitoring as required by the IHA. SOI 
notes that, if, as in 2006 and 2007, mitigation monitoring is required 
to ensure that large aggregations of mother-calf bowheads do not 
approach to within the

[[Page 36058]]

120 dB re 1 [mu]Pa (rms) radius from the active seismic operation, 
priority will be given to mitigation monitoring to the east of the 
seismic operation (see Appendix B, Figure 2). SOI suggests, that, if 
permitted by the IHA, it is prepared to conduct some surveys to collect 
data on the extent of westward deflection while still monitoring the 
120-dB radius to the east of the seismic operation. These surveys will 
obtain detailed data (weather permitting) on the occurrence, 
distribution, and movements of marine mammals, particularly bowhead 
whales, within an area that extends about 100 km (62 mi) to the east of 
the primary seismic vessel to a few km west of it, and north to about 
65 km (40 mi) offshore. A westward emphasis would obtain the same data 
for an area about 100 km (62 mi) to the west of the primary seismic 
vessel and about 20 km (12 mi) east of it; again about 65 km (40 mi) 
offshore. This site-specific survey coverage will complement the 
simultaneous MMS/NMFS National Marine Mammal Laboratory Bowhead Whales 
Aerial Survey Program (BWASP) survey coverage of the broader Beaufort 
Sea area.
    The proposed survey grid will provide data both within and beyond 
the anticipated immediate zone of influence of the seismic program, as 
identified by Miller et al. (1999). Miller et al. (1999) were not able 
to determine how far upstream and downstream (i.e., east and west) of 
the seismic operations bowheads began deflecting and then returned to 
their ``normal'' migration corridor. That is an important concern for 
the Inupiat whalers. SOI notes that the proposed survey grid is not 
able to address that concern because of the need to extend flights well 
to the east to detect mother-calf pairs before they are exposed to 
seismic sounds greater than 120 dB re 1 [mu]Pa.
    It is possible that the east-west extent of seismic surveys will 
change during the season due to ice or other operational restrictions. 
If so, SOI may need to modify the aerial survey grid to maintain 
observations to 100 km (62 mi) east (or west) of the seismic survey 
area, but the total km/mi of survey that can be conducted each day are 
limited by the fuel capacity of the aircraft. The only alternative to 
ensure adequate aerial survey coverage over the entire area where 
seismic activities might influence bowhead whale distribution is to 
space the individual transects farther apart. For each 15-20 km (9.3-
12.4 mi) increase in the east-west size of the seismic survey area, the 
spacing between lines will need to be increased by 1 km (0.62 mi) to 
maintain survey coverage from 100 km (62 mi) east to 20 km (12.4 mi) 
west of the seismic activities (or vice versa). Data from the 
easternmost transects of the proposed survey grid will document the 
main bowhead whale migration corridor east of the seismic exploration 
area and will provide the baseline data on the location of the 
migration corridor relative to the coast.
    SOI does not propose to fly a smaller ``intensive'' survey grid in 
2008/2009. In previous years, a separate grid of 4-6 shorter transects 
was flown, whenever possible, to provide additional survey coverage 
within about 20 km (12.4 mi) of the seismic operations. This coverage 
was designed to provide additional data on marine mammal utilization of 
the actual area of seismic exploration and immediately adjacent waters. 
The 1996-98 studies showed that bowhead whales were almost entirely 
absent from the area within 20 km (12.4 mi) of the active seismic 
operation (Miller et al. 1997, 1998, 1999). Thus, the flying-time that 
(in the past) would have been expended on flying the intensive grid 
will be used to extend the coverage farther to the east and west of the 
seismic activity.
    Depending on the distance offshore where seismic is being 
conducted, the survey grid may not extend far enough offshore to 
document whales which could potentially deflect north of the operation. 
In this case, SOI plans to extend the north ends of the transects 
farther north so that they extend 30-35 km (19-22 mi) north of the 
seismic operation and the two most westerly (or easterly depending upon 
the survey design) lines will not be surveyed. This will mean that the 
survey lines will only extend as far west as the seismic operation or 
start as far east as the seismic operations. SOI states that it is not 
possible to move the grid north without surveying areas south of the 
seismic operation because some whales may deflect south of the seismic 
operation and that deflection must be monitored.
    If seismic surveys of the Beaufort Sea end while substantial 
numbers of bowhead whales are still migrating west, aerial survey 
coverage of the area of most recent seismic operations will continue 
for several days after seismic surveys have ended. This will provide 
``post-seismic'' data on whale distribution for comparison with whale 
distribution during seismic periods. These data will be used in 
analyses to estimate the extent of deflection during seismic activities 
and the duration of any potential deflection after surveys end. Post 
seismic coverage will not be conducted if the bowhead migration has 
ended by that time, but it is expected that due to freeze-up, seismic 
operations will move out of the Beaufort Sea before the end of the 
bowhead whale migration.
    The survey grid patterns for summer and fall time periods being 
proposed by SOI are described in SOI's IHA application.

Joint Industry Studies Program

Chukchi Sea Coastal Aerial Survey
    The only recent aerial surveys of marine mammals in the Chukchi Sea 
were conducted along coastal areas of the Chukchi Sea to approximately 
20 nmi (37 km) offshore in 2006 and 2007 in support of SOI's summer 
seismic exploration. These surveys provided data on the distribution 
and abundance of marine mammals in nearshore waters of the Chukchi Sea. 
Population sizes of several species found they may have changed 
considerably since earlier surveys were conducted and their 
distributions may have changed because of changes in ice conditions. 
SOI plans to conduct an aerial survey program in the Chukchi Sea in 
2008 that will be similar to the 2006 and 2007 programs.
    Alaskan Natives from several villages along the east coast of the 
Chukchi Sea hunt marine mammals during the summer and Native 
communities are concerned that offshore oil and gas development 
activities such as seismic exploration may negatively impact their 
ability to harvest marine mammals. Of particular concern is the 
potential impact on the beluga harvest at Point Lay and on future 
bowhead harvests at Point Hope, Wainwright and Barrow. Other species of 
concern in the Chukchi Sea include the gray whale, bearded, ringed, and 
spotted seals, and walrus. The gray whale is expected to be the most 
numerous cetacean species encountered during the proposed summer 
seismic activities, although beluga whales also occur in the area. The 
ringed seal is likely to be the most abundant pinniped species. The 
current aerial survey program has been designed to collect distribution 
data on cetaceans but will be limited in its ability to collect similar 
data on pinnipeds because of aircraft altitude.
    The aerial survey program will be conducted in support of the SOI 
seismic program in the Chukchi Sea during summer and fall of 2008/2009. 
The objectives of the aerial survey will be (1) to address data 
deficiencies in the distribution and abundance of marine mammals in 
coastal areas of the eastern Chukchi Sea; and (2) to collect and report 
data on the distribution, numbers, orientation and behavior of marine 
mammals, particularly beluga

[[Page 36059]]

whales, near traditional hunting areas in the eastern Chukchi Sea.
    With agreement from hunters in the coastal villages, aerial surveys 
of coastal areas to approximately 20 mi (37 km) offshore between Point 
Hope and Point Barrow will begin in early- to mid-July and will 
continue until mid-November or until seismic operations in the Chukchi 
Sea are completed. Weather and equipment permitting, surveys will be 
conducted twice per week during this time period. In addition, during 
the 2008/2009 field season, SOI will coordinate and cooperate with the 
aerial surveys conducted by NMML for MMS and any other groups 
conducting surveys in the same region. For a description of the aerial 
survey procedures, please see SOI's IHA application.

Acoustic ``Net'' Array: Chukchi Sea

    The acoustic ``net'' array used during the 2007 field season in the 
Chukchi Sea was designed to accomplish two main objectives. The first 
was to collect information on the occurrence and distribution of beluga 
whales that may be available to subsistence hunters near villages 
located on the Chukchi Sea coast. The second objective was to measure 
the ambient noise levels near these villages and record received levels 
of sounds from seismic survey activities further offshore in the 
Chukchi Sea.
    The net array configuration used in 2007 is again proposed for 
2008/2009. The basic components are 30 ocean bottom hydrophones (OBH) 
systems. Two separate deployments with different placement 
configurations are planned. The first deployment will occur in mid-July 
immediately following the beluga hunt and will be adjusted to avoid any 
interference with the hunt. The initial net array configuration will 
include and extend the 2006 configuration (see Figures 8 and 9 in 
Appendix B of SOI's application for number of OBHs and locations for 
the two deployments). These offshore systems will capture seismic 
exploration sounds over large distances to help characterize the sound 
transmission properties of larger areas of the Chukchi Sea.
    The second deployment will occur in late August at the same time 
that all currently deployed systems will be recovered for battery 
replacement and data extraction. The second deployment emphasizes the 
offshore coverage out to 72 degrees North (80 nm north of Wainwright, 
150 nm (172 mi; 278 km) north of Point Lay, and 180 nm (207mi; 333 km) 
north of Cape Lizbourne. The primary goal of extending the arrays 
further offshore later in the season is to obtain greater coverage of 
the central Chukchi Sea to detect vocalization from migrating bowheads 
starting in September. The specific geometries and placements of the 
arrays are primarily driven by the objectives of (a) detecting the 
occurrence and approximate offshore distributions of belugas and 
possibly bowhead whales during the July to mid-August period and 
primarily by bowhead whales during the mid-August to late-October 
period, (b) measuring ambient noise, and (c) measuring received levels 
of seismic survey activities. Timing of deployment and final positions 
will b subject to weather and ice conditions, based on consultation 
with local villages, and carried out to minimize any interference with 
subsistence hunting or fishing activities.
    Additionally, a set of 4 to 6 OBH systems will be deployed near the 
end of the season to collect data throughout the winter.

Acoustic Array: Beaufort Sea

    In addition to the continuation of the acoustic net array program 
in the Chukchi Sea in 2008/2009, SOI proposes to also continue a 
program that deployed directional acoustic recording systems in the 
Beaufort Sea. The purpose of the array will be to further understand, 
define, and document sound characteristics and propagation resulting 
from offshore seismic and other industry operations that may have the 
potential to cause deflections of bowhead whales from anticipated 
migratory pathways. Of particular interest will be the east-west extent 
of deflection (i.e. how far east of a sound source do bowheads begin to 
deflect and how far to the west beyond the sound source does deflection 
persist). Of additional interest will be the extent of offshore 
deflection that occurs.
    In previous work around seismic and drill-ship operations in the 
Alaskan Beaufort Sea, the primary method for studying this question has 
been aerial surveys. Acoustic localization methods provide a 
supplementary methods for addressing these questions. As compared with 
aerial surveys, acoustic methods have the advantage of providing a 
vastly larger number of whale detections, and can operate day or night, 
independent of visibility, and to some degree independent of ice 
conditions and sea state-all of which prevent or impair aerial surveys. 
However, acoustic methods depend on the animals to call, and to some 
extent assume that calling rate is unaffected by exposure to industrial 
noise. Bowheads do call frequently in the fall, but there is some 
evidence that their calling rate may be reduced upon exposure to 
industrial sounds, complicating interpretation. The combined use of 
acoustic and aerial survey methods will provide information about these 
issues.
    SOI has contracted with Greeneridge to conduct the whale acoustic 
monitoring program using the passive acoustics techniques developed and 
used successfully since 2001 for monitoring the bowhead migration past 
BP's Northstar oil production facility northwest of Prudhoe Bay. Those 
techniques involve using directional autonomous seafloor acoustic 
recorders (DASARs) to measure the arrival angles of bowhead calls at 
known locations, then triangulating to locate the calling whale. 
Thousands, in some years tens of thousands, of whale calls have been 
located each year since 2001. The 2008/2009 study will use a new model 
of the DASAR similar to those deployed in 2007. Figure 11 in Appendix B 
of SOI's IHA application shows potential locations of the DASARs. The 
results of these data will be used to determine the extent of 
deflection of migrating bowhead whales from the sound sources. More 
information on DASARs and this part of SOI's monitoring program can be 
found in SOI's IHA application.

Additional Mitigation and Monitoring Measures

    In addition to the standard mitigation and monitoring measures 
mentioned previously, NMFS is proposing to incorporate additional 
mitigation/monitoring measures (such as expanded monitoring-safety 
zones for bowhead and gray whales, and having those zones monitored 
effectively) into the 2008/2009 IHA to ensure that impacts on marine 
mammals are at the lowest level practicable. The additional mitigation 
measures are specific for the SOI seismic project, in part because SOI 
incorporated monitoring measures in the 4MP document that makes this 
monitoring practicable. It should be recognized that these mitigation/
monitoring measures do not establish NMFS policy applicable to other 
projects or other locations under NMFS' jurisdiction, as each 
application for an IHA is context-specific. These measures have been 
developed based upon available data specific to the project areas. NMFS 
and MMS intend to collect additional information from all sources, 
including industry, non-governmental organizations, Alaska Natives and 
other federal and state agencies regarding measures necessary for 
effectively monitoring marine mammal populations, assessing impacts 
from seismic on marine mammals, and

[[Page 36060]]

determining practicable measures for mitigating those impacts. MMS and 
NMFS anticipate that mitigation measures applicable to future seismic 
and other activities may change and evolve based on newly-acquired 
data.

Reporting

Daily Reporting

    In its IHA application, SOI proposes to collect, via the aerial 
flights, unanalyzed bowhead sighting and flightline data which will be 
exchanged between MMS and SOI on a daily basis during the field season. 
NMFS is proposing that each team will also submit its sighting 
information to NMFS in Anchorage each day. After the SOI and MMS data 
files have been reviewed and finalized, they will be shared in digital 
form.

Interim Report

    The results of the 2008 SOI vessel-based monitoring, including 
estimates of take by harassment, will be presented in the ``90 day'' 
and final Technical Report as required by NMFS under IHAs. SOI proposes 
that the Technical Report will include: (1) summaries of monitoring 
effort: total hours, total distances, and distribution through study 
period, sea state, and other factors affecting visibility and 
detectability of marine mammals; (2) analyses of the effects of various 
factors influencing detectability of marine mammals: sea state, number 
of observers, and fog/glare; (3) species composition, occurrence, and 
distribution of marine mammal sightings including date, water depth, 
numbers, age/size/gender categories, group sizes, and ice cover; (4) 
sighting rates of marine mammals versus operational state (and other 
variables that could affect detectability); (5) initial sighting 
distances versus operational state; (6) closest point of approach 
versus seismic state; (7) observed behaviors and types of movements 
versus operational state; (8) numbers of sightings/individuals seen 
versus operational state; (9) distribution around the drilling vessel 
and support vessels versus operational state; and (10) estimates of 
take based on (a) numbers of marine mammals directly seen within the 
relevant zones of influence (160 dB, 180 dB, 190 dB (if SPLs of that 
level are measured)), and (b) numbers of marine mammals estimated to be 
there based on sighting density during daytime hours with acceptable 
sightability conditions. This report will be due 90 days after 
termination of the 2008 open water season and will include the results 
from any seismic work conducted in the Chukchi/Beaufort Seas in 2008 
under the previous IHA.

Comprehensive Monitoring Reports

    In November, 2007, SOI (in coordination and cooperation with other 
Arctic seismic IHA holders) released a final, peer-reviewed edition of 
the 2006 Joint Monitoring Program in the Chukchi and Beaufort Seas, 
July-November 2006 (LGL, 2007). This report is available for 
downloading on the NMFS website (see ADDRESSES). A draft comprehensive 
report for 2007 was provided to NMFS and those attending the NMFS/MMS 
Arctic Ocean open water meeting in Anchorage, AK on April 14-16, 2008. 
Based on reviewer comments made at that meeting, SOI is currently 
revising this report and plans to make it available to the public 
shortly.
    Following the 2008 open water season, a comprehensive report 
describing the proposed acoustic, vessel-based, and aerial monitoring 
programs will be prepared. The 2008 comprehensive report will describe 
the methods, results, conclusions and limitations of each of the 
individual data sets in detail. The report will also integrate (to the 
extent possible) the studies into a broad based assessment of industry 
activities and their impacts on marine mammals in the Beaufort Sea 
during 2008 (work conducted in 2009 under the proposed 2008/2009 IHA 
will be analyzed in a 2009 comprehensive report). The 2008 report will 
form the basis for future monitoring efforts and will establish long 
term data sets to help evaluate changes in the Beaufort/Chukchi Sea 
ecosystems. The report will also incorporate studies being conducted in 
the Chukchi Sea and will attempt to provide a regional synthesis of 
available data on industry activity in offshore areas of northern 
Alaska that may influence marine mammal density, distribution and 
behavior.
    This comprehensive report will consider data from many different 
sources including two relatively different types of aerial surveys; 
several types of acoustic systems for data collection (net array, 
passive acoustic monitoring, vertical array, and other acoustical 
monitoring systems that might be deployed), and vessel based 
observations. Collection of comparable data across the wide array of 
programs will help with the synthesis of information. However, 
interpretation of broad patterns in data from a single year is 
inherently limited. Much of the 2008 data will be used to assess the 
efficacy of the various data collection methods and to establish 
protocols that will provide a basis for integration of the data sets 
over a period of years.

Endangered Species Act (ESA)

    Under section 7 of the ESA, the NMFS has begun consultation with 
MMS on the proposed seismic survey activities in the Beaufort and 
Chukchi seas during 2008/2009. NMFS will also consult on the issuance 
of the IHA under section 101(a)(5)(D) of the MMPA to SOI for this 
activity. Consultation will be concluded prior to NMFS making a 
determination on the issuance of an IHA.

National Environmental Policy Act (NEPA)

    In 2006, the MMS prepared Draft and Final Programmatic 
Environmental Assessments (PEAs) for seismic surveys in the Beaufort 
and Chukchi Seas. Availability of the Draft and Final PEA was noticed 
by NMFS in several Federal Register notices regarding issuance of IHAs 
to SOI and others. NMFS was a cooperating agency in the preparation of 
the MMS PEA. On November 17, 2006, NMFS and MMS announced that they 
were jointly preparing a Draft Programmatic Environmental Impact 
Statement (PEIS) to assess the impacts of MMS' annual authorizations 
under the Outer Continental Shelf (OCS) Lands Act to the U.S. oil and 
gas industry to conduct offshore geophysical seismic surveys in the 
Chukchi and Beaufort seas off Alaska, and NMFS' authorizations under 
the MMPA to incidentally harass marine mammals while conducting those 
surveys. On March 30, 2007, the Environmental Protection Agency (EPA) 
noticed the availability for comment of the NMFS/MMS Draft PEIS. A 
Final PEIS has not been completed. In order to meet NMFS' NEPA 
requirements for the proposed IHA to SOI, NMFS is preparing a 
supplement to the 2006 Final PEA which incorporates by reference the 
2006 Final PEA and other related documents. Upon completion, a copy of 
this Supplemental EA will be available upon request.

Preliminary Determinations

    Based on the information provided in SOI's application, this 
document, the MMS 2006 Final PEA for Arctic Seismic Surveys, the 2006 
and 2007 Comprehensive Monitoring Reports by SOI and others, and NMFS' 
2008 Final Supplemental EA, NMFS has preliminarily determined that the 
impact of SOI conducting seismic surveys in the northern Chukchi Sea 
and eastern and central Beaufort Sea in 2008/2009 will have no more 
than a negligible impact on marine mammals and that there will not be 
any

[[Page 36061]]

unmitigable adverse impacts to subsistence communities, provided the 
mitigation measures described in this document are implemented (see 
Mitigation).
    For reasons explained previously in this document, NMFS has 
preliminarily determined that no take by serious injury, death or 
stranding is anticipated by, or authorized to, SOI's 2008/2009 seismic 
survey activities, and the potential for temporary or permanent hearing 
impairment is low and will be avoided through the incorporation of the 
mitigation measures mentioned in this document. The best scientific 
information indicates that an auditory injury is unlikely to occur as 
apparently sounds need to be significantly greater than 180 dB for 
injury to occur. NMFS has preliminarily determined that exposure to 
several seismic pulses at received levels near 200-205 dB (rms) might 
result in slight TTS in hearing in a small odontocete. Seismic pulses 
with received levels of 200-205 dB or more are usually restricted to a 
radius of no more than 200 m (656 ft) around a seismic vessel operating 
a large array of airguns. For baleen whales, while there are no data, 
direct or indirect, on levels or properties of sound that are required 
to induce TTS, there is a strong likelihood that baleen whales 
(bowheads, gray whales and humpback whales) would avoid the approaching 
airguns (or vessel) before being exposed to levels high enough for 
there to be any possibility of onset of TTS. For pinnipeds, information 
indicates that for single seismic impulses, sounds would need to be 
higher than 190 dB rms for TTS to occur while exposure to several 
seismic pulses indicates that some pinnipeds may incur TTS at somewhat 
lower received levels than do small odontocetes exposed for similar 
durations. Therefore, the requirement for MMOs to monitor safety zones 
(180 dB for cetaceans, 190 dB for pinnipeds) and power-down or shutdown 
arrays even at this distance and the increasing effectiveness of an MMO 
seeing a marine mammal prior to entering a close-in zone where auditory 
injury could occur indicates to NMFS that the 180 dB and 190-dB safety 
zones for cetaceans and pinnipeds respectively, provides a sufficient 
buffer to prevent PTS in marine mammals.
    NMFS has also preliminarily determined that only small numbers of 
marine mammals will be harassed by SOI's 2008 seismic and shallow 
hazard programs. As discussed previously, the species most likely to be 
harassed during seismic surveys in the Arctic Ocean area is the ringed 
seal, with a total ``best estimate'' of 13,256 animals being 
``exposed'' to sound levels of 160 dB or greater(6,951 animals in the 
Chukchi Sea and 6,305 animals in the Beaufort Sea)(see Table 1). As 
explained previously, this does not mean that this is the number of 
ringed seals that will actually have a behavioral reaction to the 
noise, rather it is simply the best estimate of the number of animals 
that potentially could have a behavioral modification due to the noise. 
For example Moulton and Lawson (2002) indicate that most pinnipeds 
exposed to seismic sounds lower than 170 dB do not visibly react to 
that sound; pinnipeds are not likely to react to seismic sounds unless 
they are greater than 170 dB re 1 microPa (rms). In addition as 
discussed previously, these estimates are calculated based upon line 
miles of survey effort (also animal density and the calculated zone of 
influence), the resulting take estimate numbers tend to be highly 
inflated, because animals that might have been affected (taken) are 
likely to have moved out of the area to avoid additional annoyance from 
the seismic sounds (assuming they were taken in the first place). As a 
result, NMFS believes that these ``exposure'' estimates for pinnipeds 
are conservative and seismic and shallow hazard surveys will actually 
affect significantly less than 5 percent of the Beaufort and Chukchi 
Sea ringed seal populations. This preliminary finding also applies to 
other pinniped species in the Arctic.
    Even if the estimate of 13,256 ringed seals being behaviorally 
harassed is not a small number in absolute terms, it is relatively 
small, representing only about 5.3 percent of the regional stock size 
of that species (249,000), if each ``exposure'' at 160 dB represents an 
individual ringed seal that has reacted to that sound and less if a 
higher SPL is required for a behavioral reaction (as is expected) or 
animals moved out of the seismic area. As a result, we believe that 
these ``exposure'' estimates are conservative and seismic and shallow 
hazard surveys will actually affect significantly less than 5 percent 
of the Beaufort and Chukchi Sea ringed seal populations. This finding 
also applies to other pinniped species in the Arctic.
    The estimated number of Level B harassment takes represented as 
``exposures'' during SOI's seismic and shallow hazard surveys in the 
Beaufort and Chukchi seas is 297 beluga (63 in the Chukchi Sea, 234 in 
the Beaufort Sea) and 1,540 bowheads (9 in the Chukchi Sea and 1,531 in 
the Beaufort Sea). The Level B harassment ``take'' estimate represents 
less than 1 percent of the combined Beaufort and Chukchi Seas beluga 
stock size of 42,968 (39,258 in the Beaufort Sea; 3,710 in the Chukchi 
Sea), a relatively small number. For bowhead whales, this Level B 
harassment ``take'' estimate represents between 12 percent (based on 
13,326 bowheads which assumes a 3.4 percent annual population growth 
rate from the 2001 estimate) and 14 percent of the Bering-Chukchi-
Beaufort Seas bowhead population (based on the 2001 population estimate 
of 10,545 animals). However, NMFS currently estimates that this 
population percentage estimate will be lower because SOI has 
significantly reduced its planned days of seismic surveys in the 
Beaufort Sea to only 20 days (September 25 to about October 15th or 
when surveys are curtailed by ice).
    While these exposure numbers may represent a somewhat sizable 
portion of the population size of bowhead whales (12-14 percent), NMFS 
believes that the estimated number of bowhead exposures overestimate 
actual takings for the following reasons: (1) SOI plans to concentrate 
its 3D seismic survey program in 2008 in the Lease Sale 193 area of the 
Chukchi Sea and only move into the Beaufort Sea after the bowhead 
subsistence hunt is completed (and a sizeable portion of the bowhead 
population will have migrated past SOI's planned seismic location by 
that time), and (2) the proposed shallow hazard survey activities would 
occur in the Chukchi and Beaufort seas at a time when bowheads are 
mostly concentrated in the Canadian Beaufort Sea. As a result, NMFS has 
preliminarily determined that relatively few bowhead whales will be 
taken and that only small numbers of marine mammals will be harassed by 
SOI's 2008 seismic and shallow hazard programs.
    Therefore, NMFS has preliminarily determined that the short-term 
impact of conducting seismic surveys in the U.S. Chukchi and Beaufort 
seas may result, at worst, in a temporary modification in behavior by 
certain species of marine mammals. While behavioral and avoidance 
reactions may be made by these species in response to the resultant 
noise, this behavioral change is expected to have a negligible impact 
on the animals. While the number of potential incidental harassment 
takes will depend on the distribution and abundance of marine mammals 
(which vary annually due to variable ice conditions and other factors) 
in the area of seismic operations, the number of potential harassment 
takings is estimated to be small (see Estimated Takes for NMFS' 
analysis). In addition, for reasons described previously, injury 
(temporary

[[Page 36062]]

or permanent hearing impairment) and/or mortality is unlikely and will 
be avoided through the incorporation of the mitigation measures 
mentioned in this document and required by the authorization. No 
rookeries, mating grounds, areas of concentrated feeding, or other 
areas of special significance for marine mammals occur within or near 
the planned area of operations during the season of operations.
    Finally, NMFS has preliminarily determined that the proposed 
seismic activity by SOI in the northern Chukchi Sea and central and 
eastern Beaufort Sea in 2008/2009 will not have an unmitigable adverse 
impact on the subsistence uses of bowhead whales and other marine 
mammals. This preliminary determination is supported by the information 
in this Federal Register Notice, including: (1) Seismic activities in 
the Chukchi Sea will not begin until after July 20 by which time the 
spring bowhead hunt is expected to have ended; (2) that the fall 
bowhead whale hunt in the Beaufort Sea will either be governed by a CAA 
between SOI and the AEWC and village whaling captains or by mitigation 
measures to protect subsistence hunting of marine mammals contained in 
the IHA; (3) the CAA or IHA conditions will significantly reduce 
impacts on subsistence hunters to ensure that there will not be an 
unmitigable adverse impact on subsistence uses of marine mammals; (4) 
while it is possible that accessibility to belugas during the spring 
subsistence beluga hunt could be impaired by the survey, it is unlikely 
because very little of the proposed survey is within 25 km (15.5 mi) of 
the Chukchi Sea coast, meaning the vessel will usually be well offshore 
and away from areas where seismic surveys would influence beluga 
hunting by communities; and (5) because seals (ringed, spotted, 
bearded) are hunted in nearshore waters and the seismic survey will 
remain offshore of the coastal and nearshore areas of these seals where 
natives would harvest these seals, it should not conflict with harvest 
activities.
    As a result of these preliminary determinations, NMFS proposes to 
issue an IHA to SOI for conducting a seismic survey in the northern 
Chukchi Sea and central and eastern Beaufort Sea in 2008/2009, provided 
the previously mentioned mitigation, monitoring, and reporting 
requirements are incorporated.

    Dated: June 20, 2008.
P. Michael Payne,
Acting Director, Office of Protected Resources, National Marine 
Fisheries Service.
[FR Doc. E8-14393 Filed 6-24-08; 8:45 am]
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