[Federal Register Volume 72, Number 109 (Thursday, June 7, 2007)]
[Notices]
[Pages 31553-31568]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-10953]


-----------------------------------------------------------------------

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 010207A]


Small Takes of Marine Mammals Incidental to Specified Activities; 
Seismic Surveys in the Beaufort and Chukchi Seas off Alaska

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.

-----------------------------------------------------------------------

SUMMARY:  NMFS has received an application from Shell Offshore, Inc. 
(SOI) and 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 mid and eastern Beaufort and on pre-lease areas in the 
Northern Chukchi Sea. 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 harassment, small numbers of 
several species of marine mammals between mid-July and November, 2007 
incidental to conducting seismic surveys.

DATES:  Written comments and information must be received no later than 
July 9, 2007.

ADDRESSES:  Written comments on the application should be addressed to 
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. The mailbox address 
for providing e-mail comments is PR1.010207A @noaa.gov. 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. 
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 the address provided here.
    A copy of the NMFS/Minerals Management Service's (MMS) Draft 
Programmatic Environmental ImpactStatement (Draft PDEIS) is available 
on CD from the person listed below (see ADDRESSES) and at: http://www.mms.gov/alaska/.

FOR FURTHER INFORMATION CONTACT: Kenneth Hollingshead, Office of 
Protected Resources, NMFS, (301) 713-2289 or Brad Smith, NMFS Anchorage 
(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 a complete application followed by a 30-

[[Page 31554]]

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 November 22, 2006, 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 2007 in the mid- 
and eastern-Beaufort and northern Chukchi seas. SOI's 2007 open water 
seismic program includes: (1) Chukchi Sea Deep 3D Seismic, (2) Beaufort 
Sea Deep 3D Seismic; and (3) Beaufort Sea Marine Surveys (including 
site clearance and shallow hazards (sonar, shallow seismic, acoustic 
monitoring studies, seabed topography and environmental monitoring)).
    The deep seismic survey component 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 air gun and 
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 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 Kilabuk, or similar 
ice-class vessel. The Kilabuk will serve as a resupply, fueling support 
of acoustic and marine mammal monitoring, and seismic chase vessel. It 
also is capable of assisting in ice management operations but will not 
deploy seismic acquisition gear.

Plan for Seismic Operations

    SOI plans for the M/V Gilavar to be in the Chukchi Sea in early 
July to begin deploying the acquisition equipment. Seismic acquisition 
is planned to begin on or about July 15, 2007. However, the proposed 
commencement date of July 15 will not occur earlier than that even if 
marine conditions allow since the timing 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 July.
    The approximate area of operations are shown in Figure 1 in SOI's 
IHA application. Data acquisition will continue in the Chukchi Sea 
until ice conditions permit a transit into the Beaufort Sea around 
early August. Seismic acquisition is planned to continue in the 
Beaufort at one of three 3-D areas until early October depending on ice 
conditions. For each of the 3-D areas, the M/V Gilavar will traverse 
the area multiple times until data over the area of interest has been 
recorded. While SOI's application notes that at the conclusion of 
seismic acquisition in the Beaufort Sea, the M/V Gilavar will return to 
the Chukchi Sea and resume recording data there until near the end of 
October, SOI has confirmed that it does not plan to return to the 
Chukchi Sea following completion of its seismic work in the Beaufort 
Sea.
    The proposed Beaufort Sea activities are proposed to commence in 
August and continue until weather precludes further seismic work. The 
deep seismic program will take place in OCS waters on SOI's leases 
beginning east of the Colville River delta to east of the village of 
Kaktovik. Within this area, SOI has acquired four separate groups of 
lease blocks, totaling 85 leases. The timing of activities is scheduled 
to avoid any conflict with the Beaufort Sea bowhead whale subsistence 
hunt conducted by the Alaska Eskimo Whaling Commission's (AEWC) 
villages.

Chukchi Sea Deep 3D Seismic

    The proposed deep seismic survey in the Chukchi Sea will occur 
before the survey activity in the Beaufort Sea. As sea ice coverage 
conditions allow, seismic activity will begin approximately July 15 and 
continue to early-to-mid August when the M/V Gilavar and M/V Kilabuk, 
or similar vessel, will transit to the Beaufort Sea to start work on a 
deep seismic survey on SOI lease-holdings in the mid and eastern 
Beaufort. The M/V Peregrine or similar vessel will conduct crew change 
transfers. After mid-October when sea ice conditions in the mid and 
eastern Beaufort Sea make further survey work there impractical, the 
survey activity will leave the Arctic Ocean. The dates indicated here 
represent what might occur under ideal conditions for performing marine 
seismic work whereas the actual dates will depend on sea ice and 
weather conditions as they occur in summer and mid-autumn of 2007.
    The geographic region where the proposed deep seismic survey will 
occur is the Chukchi Sea MMS OCS Program Area designated as Chukchi Sea 
Sale 193 (1989) and the proposed 2002-2007 Chukchi Sea Program Area 
(See Figure 1, MMS Chukchi Sea Sale 193). Since the Chukchi deep 
seismic program is being conducted most likely as a pre-lease activity, 
the exact locations where operations will occur remain confidential for 
business competitive reasons. That is, the seismic data acquired will 
be used by SOI to determine what leases it will bid on in a forth-
coming competitive lease sale. In general, however, seismic acquisition 
will take place well offshore from the Alaska coast beyond any 
exclusion areas stipulated in the MMS Chukchi Sea Planning Area Oil and 
Gas Lease Sale EIS 193 on OCS waters averaging greater than 40 meter 
(m) depths.

Beaufort Sea Deep 3D Seismic

    The deep seismic program will take place in OCS waters on SOI 
leases beginning east of the Colville River delta to east of the 
village of Kaktovik (see Figure 2 in SOI's application). Within this 
area, SOI has acquired four separate groups of lease blocks, totaling 
85 leases. The program is planned to occur during open-water from late 
July to the end of October.
    SOI plans to run approximately 6,437 km (4000 mi) of seismic 
surveys in the Chukchi and Beaufort Seas.

Beaufort Sea Marine Surveys

    Marine surveys will include site clearance and shallow hazards 
surveys of potential exploratory drilling locations within SOI's OCS 
lease areas and a potential pipeline corridor within and outside of SOI 
OCS lease blocks as required by MMS regulations. Site clearance surveys 
are confined to small specific areas within OCS blocks. Site clearance 
surveys are to take place at specific sites on various SOI leases from 
the Sivulliq lease block north of Pt. Thomson east to the Olympia block 
north of Barter Island (Figure 2 in SOI's IHA application). All of 
these sites are in OCS waters. Additional site clearance studies are 
planned over a corridor from the center of the Sivulliq lease block 
south to Pt. Thomson, a distance of approximately 22.4 km (14 mi). Site 
clearance surveys will be conducted contemporaneously with SOI's 3D 
seismic survey program.
    The site clearance and shallow hazards surveys will be conducted by 
the M/V Henry Christoffersen, the same vessel used during SOI's 2006 
site clearance and shallow hazard surveys). It is proposed that the 
same acoustic

[[Page 31555]]

instrumentation during 2006 will again be used during 2007: (1) Dual 
frequency subbottom profiler Datasonics CAP6000 Chirp II (2-7kHz or 8-
23 kHz); Medium penetration subbottom profiler, Datasonics SPR-1200 
Bubble Pulser (400 (hertz [Hz]); (2) hi-resolution multi-channel 2D 
system, 240 cubic inches (in\3\)(4X60) gun array (0-150 Hz); (3) multi-
beam bathymetric sonar, Seabat 8101 (240 Hz); and (4) side-scan sonar 
system, Datasonics SIS-1500 (190 - 210 kHz). These systems are 
described in SOI's IHA application.
    These systems will be used in order to examine and measure 
bathymetry, seabed topography, potential geohazards and other seabed 
characteristics (i.e. boulder patches). The site-specific locations of 
site clearance and shallow hazard surveys have not been definitively 
set, although they will occur within the area outlined in Figure 2 in 
SOI's IHA application. In addition, several (more than 10) sonabouys 
(passive acoustic monitoring equipment) are to be positioned in and 
around potential drilling locations within the Sivulliq lease block. 
SOI states that the timing of the activity is scheduled to avoid 
conflict with the Beaufort Sea subsistence hunts conducted by the 
Whaling Captain's Associations of Barrow, Kaktovik, and Nuiqsut (see 
Mitigation).
    The multi-beam bathymetric sonar and the side-scan sonar systems 
operate at frequencies greater than 180 kHz, the highest frequency 
considered by knowledgeable marine mammal biologists to be of possible 
influence to marine mammals. No measurements of those two sources are 
planned, as the recording equipment has a practical upper limit of 90 
kHz. As determined during the sound measurement process, there should 
be no exclusion zones for seals or whales during operation of those two 
sources.
    Acoustic systems similar to the ones proposed for use by SOI have 
been described in detail 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 detailed description of the work proposed by SOI for 2007 is 
contained in SOI's application which is available for review (see 
ADDRESSES). A description of SOI's data acquisition program and 
WesternGeco's air-gun array 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) and is no different than previous programs.

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

    Shell will 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 gun arrangement for each of the three 1049-in\3\ sub-array is 
detailed in Shell's application. As indicated in the application's 
diagram, each sub-array is composed of six tuning elements; two 2-gun 
clusters and four single guns. The standard configuration of a source 
array for 3D 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

    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 as there 
are no differences. 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.

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).

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 PEA. Information on these 
marine mammal species can also be found in NMFS Stock Assessment 
Reports (SARS). The Alaska SARS document is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2005.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

[[Page 31556]]

source of noise. The physical presence of vessels and aircraft could 
also lead to non-acoustic disturbance or avoidance 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 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

    SOI (2006) states that the only anticipated impacts to marine 
mammals associated with noise propagation from vessel movement, seismic 
airgun operations, and seabed profiling would be the temporary and 
short term displacement of seals and whales from within ensonified 
zones produced by such noise sources. 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 lower than 160 db (Richardson et al., 1999). The cited and other 
studies conducted to test the hypothesis of the deflection response of 
bowheads have determined that bowheads return to the swim paths they 
were following at relatively short distances after their exposure to 
the received sounds. SOI believes that there is no evidence that 
bowheads so exposed have incurred injury to their auditory mechanisms. 
Additionally, SOI cites Richardson and Thomson [eds]. (2002) that there 
is no conclusive evidence that exposure to sounds exceeding 160 db have 
displaced bowheads from feeding activity.
    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). It is also uncertain how far beyond (west of) the 
seismic operation the seaward deflection persists (Miller et al., 
1999). In one study, although very few bowheads approached within 20 km 
(12.4 mi) of the operating seismic vessel, the number of bowheads 
sighted within that area returned to normal within 12-24 hours after 
the airgun operations ended (Miller et al., 1999).
    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 (Western Geophysical, 2000).
    Hearing damage is not expected to occur during the SOI seismic 
survey project. It is not definitively known whether the hearing 
systems of marine mammals very close to an airgun would be at risk of 
temporary or permanent hearing impairment, but TTS is a theoretical 
possibility for animals within a few hundred meters of the source 
(Richardson et al., 1995). However, planned monitoring and mitigation 
measures to detect marine mammals occurring near the array (described 
later in this document) are designed to avoid sudden onsets of seismic 
pulses at full power. These measures are likely to prevent animals from 
being exposed to sound pulses that have any possibility of causing 
hearing impairment.
    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 among 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, are less 
likely than resting animals to show overt behavioral reactions, unless 
the disturbance is directly threatening.
    The following species summaries are provided by NMFS to facilitate 
understanding of our knowledge of impulsive noise impacts on the 
principal marine mammal species that are expected to be affected.

Bowhead Whales

    Seismic pulses are known to cause strong avoidance reactions by 
many of the bowhead whales occurring within a distance of a few 
kilometers, including changes in surfacing, respiration and

[[Page 31557]]

dive cycles, and may sometimes cause avoidance or other changes in 
bowhead behavior at considerably greater distances (Richardson et al., 
1995; Rexford, 1996; MMS, 1997). Studies conducted prior to 1996 
(Reeves et al., 1984, Fraker et al., 1985, Richardson et al., 1986, 
Ljungblad et al., 1988) have reported that, when an operating seismic 
vessel approaches within a few kilometers, most bowhead whales exhibit 
strong avoidance behavior and changes in surfacing, respiration, and 
dive cycles. In these studies, bowheads exposed to seismic pulses from 
vessels more than 7.5 km (4.7 mi) away rarely showed observable 
avoidance of the vessel, but their surface, respiration, and dive 
cycles appeared altered in a manner similar to that observed in whales 
exposed at a closer distance (Western Geophysical, 2000). In three 
studies of bowhead whales and one of gray whales during this period, 
surfacing-dive cycles were unusually rapid in the presence of seismic 
noise, with fewer breaths per surfacing and longer intervals between 
breaths (Richardson et al., 1986; Koski and Johnson, 1987; Ljungblad et 
al., 1988; Malme et al., 1988). This pattern of subtle effects was 
evident among bowheads 6 km to at least 73 km (3.7 to 45.3 mi) from 
seismic vessels. However, in the pre-1996 studies, active avoidance 
usually was not apparent unless the seismic vessel was closer than 
about 6 to 8 km (3.7 to 5.0 mi)(Western Geophysical, 2000).
    Inupiat whalers believe that migrating bowheads are sometimes 
displaced at distances considerably greater than suggested by pre-1996 
scientific studies (Rexford, 1996) previously mentioned in this 
document. Also, whalers believe that avoidance effects can extend out 
to distances on the order of 30 miles (48.3 km), and that bowheads 
exposed to seismic also are ``skittish'' and more difficult to 
approach. The ``skittish'' behavior may be related to the observed 
subtle changes in the behavior of bowheads exposed to seismic pulses 
from distant seismic vessels (Richardson et al., 1986).

Gray Whales

    The reactions of gray whales to seismic pulses are similar to those 
documented for bowheads during the 1980s. Migrating gray whales along 
the California coast were noted to slow their speed of swimming, turn 
away from seismic noise sources, and increase their respiration rates. 
Malme et al. (1983, 1984, 1988) concluded that approximately 50 percent 
of the migrating gray whales showed avoidance when the average received 
pulse level was 170 dB (re 1 microPa). By some behavioral measures, 
clear effects were evident at average pulse levels of 160+dB; less 
consistent results were suspected at levels of 140-160 dB. Recent 
research on migrating gray whales showed responses similar to those 
observed in the earlier research when the source was moored in the 
migration corridor 2 km (1.2 mi) from shore. However, when the source 
was placed offshore (4 km (2.5 mi) from shore) of the migration 
corridor, the avoidance response was not evident on track plots (Tyack 
and Clark, 1998).

Beluga

    The beluga is the only species of toothed whale (Odontoceti) 
expected to be encountered in the Beaufort Sea. Belugas have poor 
hearing thresholds at frequencies below 200 Hz, where most of the 
energy from airgun arrays is concentrated. Their thresholds at these 
frequencies (as measured in a captive situation), are 125 dB re 1 
microPa or more depending upon frequency (Johnson et al., 1989). 
Although not expected to be significantly affected by the noise, given 
the high source levels of seismic pulses, airgun sounds sometimes may 
be audible to beluga at distances of 100 km (62.1 mi)(Richardson and 
Wursig, 1997), and perhaps further if actual low-frequency hearing 
thresholds in the open sea are better than those measured in captivity 
(Western Geophysical, 2000). The reaction distance for beluga, although 
presently unknown, is expected to be less than that for bowheads, given 
the presumed poorer sensitivity of belugas than that of bowheads for 
low-frequency sounds (Western Geophysical, 2000).

Ringed, Largha and Bearded Seals

    No detailed studies of reactions by seals to noise from open water 
seismic exploration have been published (Richardson et al., 1995). 
However, there are some data on the reactions of seals to various types 
of impulsive sounds (LGL and Greeneridge, 1997, 1998, 1999a; J. Parsons 
as quoted in Greene, et al. 1985; Anon., 1975; Mate and Harvey, 1985). 
These studies indicate that ice seals typically either tolerate or 
habituate to seismic noise produced from open water sources.
    Underwater audiograms have been obtained using behavioral methods 
for three species of phocinid seals, ringed, harbor, and harp seals. 
These audiograms were reviewed in Richardson et al. (1995) and Kastak 
and Schusterman (1998). Below 30-50 kHz, the hearing threshold of 
phocinids is essentially flat, down to at least 1 kHz, and ranges 
between 60 and 85 dB (re 1 microPa @ 1 m). There are few data on 
hearing sensitivity of phocinid seals below 1 kHz. NMFS considers 
harbor seals to have a hearing threshold of 70-85 dB at 1 kHz (60 FR 
53753, October 17, 1995), and recent measurements for a harbor seal 
indicate that, below 1 kHz, its thresholds deteriorate gradually to 97 
dB (re 1 microPa @ 1 m) at 100 Hz (Kastak and Schusterman, 1998).
    While no detailed studies of reactions of seals from open-water 
seismic exploration have been published (Richardson et al., 1991, 
1995), some data are available on the reactions of seals to various 
types of impulsive sounds (see LGL and Greeneridge, 1997, 1998, 1999a; 
Thompson et al. 1998). These references indicate that it is unlikely 
that pinnipeds would be harassed or injured by low frequency sounds 
from a seismic source unless they were within relatively close 
proximity of the seismic array. For permanent injury, pinnipeds would 
likely need to remain in the high-noise field for extended periods of 
time. Existing evidence also suggests that, while seals may be capable 
of hearing sounds from seismic arrays, they appear to tolerate intense 
pulsatile sounds without known effect once they learn that there is no 
danger associated with the noise (see, for example, NMFS/Washington 
Department of Wildlife, 1995). In addition, they will apparently not 
abandon feeding or breeding areas due to exposure to these noise 
sources (Richardson et al., 1991) and may habituate to certain noises 
over time.

Numbers of Marine Mammals Expected to Be Taken

    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 are presented here. The density estimates for 
the species covered under this proposed IHA are based on the estimates 
developed by LGL (2005) and used here for consistency. Density 
estimates are based on the data from Moore et al. (2000) on summering 
bowhead, gray, and beluga whales in the Beaufort and Chukchi Seas, and 
relevant studies on ringed seal estimates including Stirling et al. 
(1982) and Kingsley (1986).
    In its application, SOI provides estimates of the number of 
potential ``exposures'' to sound levels greater than 160 dB re 1 
microPa (rms) and greater than 170 dB. SOI states that while the 160-dB 
criterion applies to all species of cetaceans and pinnipeds, SOI 
believes that a 170-dB criterion should

[[Page 31558]]

be considered appropriate for delphinid cetaceans and pinnipeds, which 
tend to be less responsive, whereas the 160-dB criterion is considered 
appropriate for other cetaceans (LGL, 2005). However, NMFS has noted in 
the past that it is unaware of any empirical evidence to indicate that 
some delphinid species do not respond at the lower level (i.e., 160 
dB). As a result, NMFS will estimate Level B harassment take levels 
based on the 160 dB criterion.
    The estimates for marine mammal exposure are based on a 
consideration of the number of marine mammals that might be disturbed 
appreciably by as much as 6,437 km (4000 mi) of seismic surveys in 
Beaufort Sea and/or the Chukchi Sea. Source arrays are composed of 
identically tuned Bolt gun sub-arrays operating at 2,000 psi, air 
pressure. 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 (in\3\) sub-array is detailed below and is comprised of 
three subarrays comprising a total 3,147 in\3\ 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 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 whale in the Beaufort Sea were taken from Miller 
et al., 2002. Table 6-1 in SOI's IHA application gives the average and 
maximum densities for each cetacean species likely to occur within the 
project areas based on the density estimates developed and corrected as 
needed by LGL for the Beaufort and Chukchi Seas (LGL, 2005), however, 
these estimates were based on surveys of offshore waters (less than 100 
m (328 ft) in depth). However, all seismic activities within the 
seismic activity areas proposed under this IHA will occur in waters 
between 20 and 40 m (65.6 and 131.2 ft) in depth. The estimated numbers 
of potential exposures presented in Tables 1 and 2 (Tables 6-3 and 6-4 
in SOI's IHA application) are based on the 160 dB re 1 microPa (rms) 
criteria for most cetaceans (except for this geographic area, bowhead 
whales), because this range is assumed to be the sound source level at 
which marine mammals may change their behavior sufficiently to be 
considered ``taken by harassment.''

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. Although the estimated numbers of potential exposures 
presented in Tables 1 and 2 (Tables 6-3 and 6-4 in the IHA application) 
are based on two sound source ranges (greater than 160 dB and greater 
than 170 dB re 1 microPa [rms]), for most pinnipeds, SOI believes that 
the 170 dB threshold should be used to determine ``take by harassment'' 
because this range is assumed to be the sound source level at which 
most pinnipeds may change their behavior in reaction to increased sound 
exposure.

Exposure Calculations for Cetaceans and Pinnipeds

    Except for bowheads in the Beaufort Sea, number of exposures of a 
particular species to sound levels between 160 dB and 180 dB re 1 
microPa (rms) was calculated by multiplying: (1) the expected species 
density average and maximum), taken from LGL (2005); (2) the maximum 
anticipated total line-km of operations in the Chukchi and/or Beaufort 
Seas the three 1,049 in\3\ subarrays (6,437 km); and (3) the cross-
track distances within which received sound levels are predicted to be 
greater than 160 dB and greater than 170 dB.
    Distances of sound propagation are taken from direct measurement of 
sound levels at distances from the M/V Gilavar in the Chukchi Sea 
during the 2006 open water season. Shell estimates the sound level 
output radii (rms)) for a 3147 in\3\ source array at a depth of 6 m (20 
ft):
    160 dB (rms) :: 8400 m/27559 ft
    180 dB (rms) :: 1200 m/3937 ft
    190 dB (rms) :: 440 m/1444 ft.
    For bowhead whales in the Beaufort Sea, Richardson et al. (2002) 
provide estimates of densities specific to a given area (subdivided 
east to west and by depth) and time (two week intervals during summer 
and fall). The total number of individuals expected to be in the 
specific area where seismic operations are to occur in the Beaufort Sea 
is multiplied by that portion of the area expected to be ensonified 
above 160 dB.
    Estimates of numbers of cetaceans and pinnipeds exposed to sound 
levels greater than 160 and 170 dB resulting from seismic acquisition 
activities in the Chukchi Sea are presented in Table 1 (Table 6-3 in 
SOI's IHA application). Estimates of exposure levels for the Beaufort 
Sea are presented in Table 2 (Table 6-4 in SOI's IHA application).

[[Page 31559]]



                                    Table 1. Estimated Exposures and Requested Take Levels for Chukchi Sea Operations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Average                                                  Maximum                                              Requested
                                Density     190 dB     180 dB     170 dB     160 dB      Density     190 dB    180 dB    170 dB    160 dB       Take
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cetaceans
  bowhead whales                0.0011    .........  17         47         119        0.006         ........  93        255       649       649
  gray whale                   0.0018     .........  28         77         195        0.0072        ........  112       306       779       779
  Beluga                       0.0034     .........  53         145        368        0.0135        ........  209       574       1,460     1,460
  killer whale                 0.0001     .........  2          5          11         0.0004        ........  7         17        44        44
  Minke whale                  0.0001     .........  2          5          11         0.0004        ........  7         17        44        44
  Fin whale                    0          .........  0          0          0          0.0001        ........  2         5         11        11
Pinnipeds
  ringed seal                  0.0234     14         362        995        .........  0.0935        53        1,445     3,973     ........  3,973
  spotted seal                 0.0002     1          4          9          .........  0.0009        1         14        39        ........  39
  bearded seal                 0.0093     6          144        396        .........  0.037         21        572       1573      ........  1573
--------------------------------------------------------------------------------------------------------------------------------------------------------


                                   Table 2. Estimated Exposures and Requested Take Levels for Beaufort Sea Operations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                Average                                                  Maximum                                              Requested
                                Density     190 dB     180 dB     170 dB     160 dB      Density     190 dB    180 dB    170 dB    160 dB       Take
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cetaceans
  bowhead whales                NA        .........  .........  .........  .........  2,004.236     ........  172       473       1203      1203
  gray whale                   0.0001     .........  2          5          11         0.0004        ........  7         17        44        44
  Beluga                       0.0068     .........  106        289        736        0.0135        ........  209       574       1,460     1,460
  Harbor Porpoise              0          .........  0          0          0          0.0002        ........  4         9         22        22
Pinnipeds
  ringed seal                  0.3547     201        5481       15071      .........  0.7094        402       10,961    30,141    ........  30,141
  spotted seal                 0.0037     3          58         158        .........  0.0149        9         231       634       ........  634
  bearded seal                 0.0181     11         280        770        .........  0.0362        21        560       1,539     ........  1,539
--------------------------------------------------------------------------------------------------------------------------------------------------------


                             Table 3. Estimated Exposures and Requested Take Levels for Beaufort Sea Henry ''C'' Operations
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                  Average                                                       Maximum
                                  Density     190 dB      180 dB      170 dB      160 dB        Density       190 dB      180 dB      170 dB     160 dB
--------------------------------------------------------------------------------------------------------------------------------------------------------
Cetaceans
  bowhead whales                 NA         ..........  ..........  ..........  ..........  2004.236        ..........  48          126        315
  gray whale                    0.0001      ..........  1           1           1           0.0004          ..........  1           1          2
  Beluga                        0.0068      ..........  3           7           18          0.0135          ..........  6           14         35
  Harbor Porpoise               0           ..........  0           0           0           0.0002          ..........  1           1          1
Pinnipeds
  ringed seal                   0.3547      49          135         359         898         0.7094          98          270         718        .........
  spotted seal                  0.0037      1           2           4           ..........  0.0149          3           6           16         .........
  bearded seal                  0.0181      3           7           19          ..........  0.0362          5           14          37         .........
--------------------------------------------------------------------------------------------------------------------------------------------------------

Beaufort Sea: Marine Surveys

    In addition to potential impacts from seismic surveys on Beaufort 
Sea marine mammals, SOI and NMFS anticipate that there is also a 
potential for marine mammals to be impacted by SOI's marine surveys (as 
described previously in this document). SOI determined that the air gun 
cluster on the M/V Henry Christoffersen was the strongest sound source 
on the vessel. Based on sound field measurements, the following 
distances were calculated: 190 dB - 89 m (292 ft); 180 dB - 248 m (814 
ft); and 160 dB - 1,750 m (5741 ft). As explained in SOI's application, 
SOI has calculated a 50 percent margin factor and recommends that these 
zones be amended to the following: 190 dB - 120 m (394 ft), 180 dB - 
330 m (1083 ft); and 160 dB - 2,220 m (7218 ft). Using similar 
methodology as for the M/V Gillivar, Table 3 (Table 6-6 in SOI's IHA 
application) provides estimates of marine mammal sound exposures at 
these SPLs for the M/V Henry Christoffersen.

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 Sea activity area 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 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). This study and others conducted to test the 
hypothesis of the deflection response of bowheads have determined that 
bowheads return to the swim paths they were following at relatively 
short distances after their exposure to the received sounds. There is 
no evidence that bowheads so exposed have incurred injury to their 
auditory mechanisms. Additionally, there is no conclusive

[[Page 31560]]

evidence that exposure to sounds exceeding 160 db have displaced 
bowheads from feeding activity (Richardson, W.J. and D.H. Thomson 
[eds]. 2002).
    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, most marine mammals would 
be dispersed throughout the area. The peak of the bowhead whale 
migration through the Chukchi Sea typically occurs in October, and 
efforts to reduce potential impacts during this time will be addressed 
with the actual start of the migration and with the whaling 
communities. The timing of seismic activities in the Chukchi Sea will 
take place when the whales are widely distributed and would be expected 
to occur in very low numbers within the seismic activity area. Starting 
in late August bowheads may travel in proximity to the aforementioned 
activity area and hear sounds from vessel traffic and seismic 
activities, of which some might be displaced seaward by the planned 
activities.
    The peak of the bowhead whale migration through the Beaufort Sea 
typically occurs in October, and efforts to reduce potential impacts 
during this time will be addressed with the actual start of the 
migration and with the whaling communities. The timing of seismic 
activities in the eastern U.S. Beaufort Sea will take place when the 
whales are not present, or in very low numbers. Starting in late August 
bowheads may travel in proximity to SOI's seismic activity areas and 
hear anthropogenic sounds from vessel traffic and seismic activities. 
Some bowheads may be displaced seaward by the planned activities.
    In addition, feeding does not appear to be an important activity by 
bowheads migrating through the Chukchi Sea or the eastern and central 
part of the Alaskan Beaufort 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 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 known important 
feeding areas in the U.S. Beaufort Sea, 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. Bowheads, gray, or beluga whales are not 
predicted to be excluded from any habitat.

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 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 LGL 
(2005; University of Alaska-Fairbanks Seismic Survey across Arctic 
Ocean at http://www.nmfs.noaa.gov/pr/permits/incidental.htm#iha), and 
includes a summary of direct mortality (pathological/physiological) and 
indirect (behavioral) effects.
    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 standard 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.

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 of the area. 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 related how whales also appear 
``angry'' due to seismic noise, making whaling more dangerous.
    This potential impact on subsistence uses of marine mammals is 
proposed 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. Under a CAA, the times and 
locations of seismic and other noise producing sources would 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 survey activities will also be scheduled to avoid the 
traditional

[[Page 31561]]

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 the whale species for subsistence uses.
    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 seismic operations will not 
begin until after July 15, 2007 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 15, 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 the past few years, a small number of bowheads have also been taken 
by coastal villages along the Chukchi coast. 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 have been incorporated 
into the CAA established between SOI and WesternGeco, the AEWC, and the 
Barrow Whaling Captains Association.
    Beluga whales may also be taken sporadically for subsistence needs 
by coastal villages, but traditionally are taken in small numbers very 
near the coast. Because the seismic surveys will be conducted at least 
12 miles (25 km) offshore, impacts to subsistence uses of bowheads are 
not anticipated. However, SOI will establish ``communication stations'' 
in the villages to monitoring 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 notes in its IHA application that 
POC meetings occurred in Barrow and Nuiqsut on October 16 and 17, 2006, 
and follow-up meetings are planned for the period May or June 2007 in 
these communities. SOI is working with all public and private 
organizations to hold a series of meetings in Kaktovik during 2006/
2007. The communities of Point Hope, Point Lay and Wainwright have met 
with SOI to discuss the results of the 2006 survey activities in the 
Chukchi Sea, followed by another series of POC meetings in May or June 
2007. Following those meetings, a POC report will be prepared.
    SOI hopes that a CAA will result from these meetings. 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 the 2007 CAA, 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 must make a determination under the 
MMPA 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 by seismic activities 
is expected to be impacts from noise on bowhead whales during its 
westward fall feeding and migration 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).
    However, it should be understood that while a signed CAA assists 
NMFS in making 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.

Proposed Mitigation and Monitoring

    As part of its application, SOI has proposed implementing a marine 
mammal mitigation and monitoring program 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

    On February 7, 2007, SOI submitted its proposed mitigation and 
monitoring program for SOI's seismic programs in the Chukchi and 
Beaufort seas. 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

[[Page 31562]]

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 > 180 dB re 1 microPa (rms) for cetaceans and >190 dB re 1 microPa 
(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 have some such effects.
    SOI anticipates that monitoring similar to that conducted in the 
Chukchi Sea in 2006 will also be required in the Chukchi and the 
Beaufort seas in 2007. 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 below. SOI also plans to monitor 
the 160 dB (rms) disturbance zone with MMOs onboard the chase vessel in 
2007 as was done in 2006. 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, there was a requirement in the IHA issued to SOI 
by NMFS to implement special mitigation measures if specified numbers 
of bowhead cow/calf pairs might be exposed to [gteqt]120 dB rms or if 
large groups (>12 individuals) of bowhead or gray whales might be 
exposed to [gteqt]160 dB rms . Monitoring of the 120 dB (rms) zone was 
required in the Chukchi Sea after 25 September. SOI anticipates that it 
will not be operating in the Chukchi Sea after 25 September, and it is 
likely, therefore, that SOI will not need to monitor the 120 dB (rms) 
zone in the Chukchi Sea in 2007. However, it is likely that SOI will be 
operating in the Beaufort Sea after 1 September in 2007, and SOI 
anticipates the need to monitor the 120 dB zone in that region.
    If, as expected, the seismic acquisition equipment used in 2007 is 
the same as the equipment used during the 2006 field season, SOI plans 
to use the same safety radii developed during 2006 for marine mammal 
mitigation in the Chukchi Sea during 2007. Initial safety radii for the 
Chukchi and Beaufort seas were modeled and estimated by JASCO Research 
Ltd. prior to seismic exploration activities in 2006. Modeling of the 
sound propagation was based on the size and configuration of the airgun 
array and on available oceanographic data. (If the airgun array used in 
2007 is different from the array used in 2006, JASCO will model and 
estimate new radii based on the specifications of the new array for 
both the Chukchi and Beaufort seas. Those safety zones will be used for 
mitigation purposes until direct measurements are available early 
during the seismic survey.) If the same seismic acquisition equipment 
used in 2006 is used during 2007, then measurements of the sound 
produced by the airgun array will only be conducted in the Beaufort 
Sea, where acoustic measurements were not conducted in 2006. 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. 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. SOI estimates that period to be about 8-10 minutes.
    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. The ramp-up 
procedure still will be followed when increasing the source levels from 
one air gun to the full arrays. However, 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 24h/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, 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

[[Page 31563]]

will be based on the distance from the bridge (vantage point for MMOs) 
rather than from the airgun array. 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. Note that if one small airgun has remained 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.

Proposed Marine Mammal Monitoring

    SOI will implement a marine mammal monitoring program (MMMP) 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 marine mammal observers 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.
Vessel-based Visual Monitoring
Seismic Source Vessel Monitoring
    SOI will have at least four observers (three trained biologists and 
at least one Inupiat observer/communicator) based aboard the seismic 
vessel. 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. These 
observers 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 observers 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 whenever the seismic array is ramped 
up. 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.
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 2007, 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 
two 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, the 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 2007 
using MMOs onboard the chase vessel as was done in 2006. The 160 dB 
(rms)radius in the Chukchi Sea in 2006 was determined by Blackwell 
(2006) to extend approximately 8.4 km (5.2 mi) from the airgun source 
on the Gilavar and was monitored by MMOs onboard the Kilabuk. During 
monitoring of the 160 dB zone, the Kilabuk followed a zig-zag pattern 
about 6-8 km (3.7-5 mi) ahead of the Gilavar. MMOs onboard the Kilabuk 
searched the area ahead of the Gilavar within the 160 dB zone for 
marine mammals. Mitigation (i.e., power down or shut down of the airgun 
array) was to be implemented if a group of 12 or more bowhead or gray 
whales entered the 160 dB zone. SOI proposes to use this same protocol 
in the Beaufort Sea after the 160 dB radius has been determined by 
direct measurement.
Underwater Seismic Acoustic Measurement Program
    As part of the IHA application process for similar seismic 
acquisition in 2006, SOI contracted to model the distances from 
WesternGeco's airgun array on the SOI source vessel, the MV Gilavar, to 
various broadband received levels of 190, 180, 170, 160, and 120 dB rms 
re 1 microPa. The model estimated the broadband received sound level in

[[Page 31564]]

water in relation to properties of the airgun array along with various 
environmental and physical characteristics. These modeled radii were 
used to define temporary safety radii that were used prior to and 
during measurements of the actual sounds produced by the airgun array 
at the beginning of the field season. These measured radii were used to 
establish actual safety radii that were used for mitigation during the 
2006 seismic exploration activities in the Chukchi Sea. In 2007, SOI 
plans to again use the Gilavar as its seismic source vessel. Assuming 
that an airgun array identical to the one used in 2006 (WesternGeco's 
3147 in\3\ Bolt-Gun Array) is used during 2007, and that SOI's seismic 
acquisition during 2007 occurs in the same general location in the 
Chukchi Sea as the 2006 surveys, SOI does not plan to make empirical 
measurements of the airgun array in 2007 in the Chukchi Sea. For this 
scenario, SOI would use the same safety radii that were developed 
during 2006 for marine mammal mitigation during the 2007 field season. 
However, SOI proposes to measure the sound propagation of the airgun 
array if (1) an airgun array different from the array used during 2006 
is used during the 2007 surveys, (2) the 2007 surveys in the Chukchi 
Sea are conducted in a different location than the surveys in 2006, or 
(3) if there is some other compelling reason to re-measure the sound 
propagation from the airgun array used during 2006.
    SOI proposes to conduct measurements of the sound produced from the 
airgun array in the Beaufort Sea. This was not accomplished in 2006 due 
the presence of ice and other logistical considerations which precluded 
the Gilavar from entering the Beaufort Sea. Sound source measurements 
will be conducted by a qualified acoustics contractor in the general 
area where seismic activities are planned. Results of the measurements 
will be used to determine the actual safety radii to be used for 
mitigation during the seismic activities. Technical details on this 
program can be found in SOI's IHA application.
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 2007. 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 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; (3) to 
support regulatory reporting and Inupiat communications related to the 
estimation of impacts of seismic operations on marine mammals; (4) to 
monitor the accessibility of bowhead whales to Inupiat hunters and (5) 
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.
    SOI proposes to implement different aerial survey designs during 
the summer (August) and fall (late August-October) periods because the 
numbers and distributions of marine mammal species of primary interest 
are different during those periods. During the early summer, few 
cetaceans are expected to be encountered in the Beaufort Sea, and those 
that are encountered are expected to be either along the coast (gray 
whales) or among the pack ice (bowheads and belugas) north of the area 
where seismic surveys and drilling activities are to be conducted.
    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. Small numbers of 
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, 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 have more-widely-spaced lines than the grid that will be 
flown during the fall period and will extend farther offshore to 
document the offshore distribution of bowhead whales and belugas
Survey Design in the Beaufort Sea in Fall
    Aerial surveys during the late August-October period will be 
designed to ensure that large aggregations of mother-calf bowheads do 
not approach to within the 120 dB re 1 microPa radius from the active 
seismic operation. At the same time, 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 to the east of the primary seismic 
vessel to a few km west of it, and north to about 65 km offshore. This 
site-specific survey coverage will complement the simultaneous 
MMS'Bowhead Whales Aerial Survey Program (BWASP) survey coverage. 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 mitigation need to extend 
flights well to the east to detect mother-calf pairs before they are 
exposed to seismic

[[Page 31565]]

sounds greater than 120 dB re 1 microPa.
    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 of the seismic survey area, but the 
total km 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 to maintain survey coverage 
from 100 km (62 mi) east to 20 km (12.4 mi) west of the seismic 
activities. 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 2007. In most 
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.
    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 deflection after surveys end. Postseismic 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.
    Survey Grids: Two different aerial survey grids are proposed 
depending on whether surveys are being conducted during summer (July to 
late August) or fall (late August-October). During summer, four north-
south lines spaced 48 km (30 mi)apart and centered on the planned 
seismic exploration area would be flown 2 times each week. They would 
extend from the barrier islands (or 10-m (32.8 ft) depth contour in 
areas with no barrier islands) north to about 72[deg] N which may be 
well within the pack ice at that time of year. The proposed survey grid 
for late August-October consists of up to 18 north-south lines spaced 8 
km (4.9 mi) apart and will extend to 100 km (62 mi) east of the then-
current seismic exploration area. Lines will extend from the barrier 
islands (or 10-m (32.8 ft) contour) north to approximately the 100 m 
(328 ft) depth contour. As previously described, when the seismic 
program moves east or west, the aerial survey grids will also be 
relocated a corresponding distance along the coast. This grid will be 
flown 2 times each week until one week prior to the start of seismic 
surveys. They will then be flown daily until one week after the end of 
seismic surveys in the Beaufort Sea. The eastern boundary of the survey 
area will extend eastward beyond the 120 dB radius of seismic sounds in 
order to detect aggregations of mother-calf pairs approaching the 
seismic operation.
    Depending on the distance offshore where seismic is being 
conducted, the survey grid that is shown may not extend far enough 
offshore to document whales deflecting north of the operation. In this 
case, the north ends of the transects will be extended farther north so 
that they extend 30-35 km (18.6-21.7 mi) north of the seismic operation 
and the two most westerly lines will not be surveyed. This will mean 
that the survey lines will only extend as far west as the seismic 
operation. It is not possible to move the survey 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. During previous studies of offshore drilling operations, 
bowhead whales were documented migrating near the coast less than 20 km 
(12.4 mi ) south of a drilling operation (Koski and Johnson, 1987). It 
would be desirable to monitor whale movements west of the seismic 
operation to document how far west bowheads move before returning to 
their normal migratory corridor. It is not possible, however, to 
monitor the 120 dB radius east of the seismic operation and obtain 
information on the distribution of whales west of the operation because 
of the large area that must be surveyed to the east.
    The ``summer'' grid will total about 1000 km (621.4 mi) in length, 
requiring 4.6 hours to survey at a speed of 220 km/hr (120 nmi/hr), 
plus ferry time which will vary according to the location of the survey 
grid relative to the logistics base. The late August-October grid will 
total about 1300 km (807.8 mi) in length, requiring 6 h to survey at a 
speed of 220 km/h (120 nmi/hr), plus ferry time. Exact lengths and 
durations will vary somewhat depending on the east-west position of the 
seismic operations area and thus of the grid, the sequence in which 
lines are flown (often affected by weather), and the number of 
refueling/rest stops. As during previous studies, we propose that, 
while whaling is underway we will not survey the southern portions of 
survey lines over or near hunting areas unless the whalers agree that 
this can be done without interfering with their activities. This will 
reduce (but not eliminate) the potential for overflying whalers and 
whales that are being approached by whalers. Some of the autumn bowhead 
sightings in the region do occur in this ``nearshore'' area, and these 
whales will not be documented if the survey aircraft remains 15 or more 
km offshore in this area at all times. If SOI does not survey this area 
while whaling is occurring, it will reduce the potential for aircraft-
whaler interactions at the expense of reducing our ability to assess 
seismic effects on bowheads, other marine mammals, and subsistence 
activities in that nearshore area.

Joint Industry Studies Program

    This section describes studies that were undertaken in 2006 in the 
Chukchi Sea that will be continued during seismic operations in 2007. 
SOI plans to conduct aerial surveys consistent with the 2006 program 
along the Chukchi Sea coast. Additionally, an acoustic ``net'' array 
will be used to monitor industry sounds and marine mammals along the 
Chukchi Sea coast. This program may be modified to include recorders at 
different or additional locations depending upon the results obtained 
from the 2006 program. Once these results are available final 
determination of the numbers and placements of the recorders will occur 
in consultation with industry partners, agencies, and other 
stakeholders. In addition to the aerial and acoustical components of 
the study program in the Chukchi Sea, SOI plans to also establish an 
acoustic net array in the Beaufort Sea in 2007.

[[Page 31566]]

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 in support of SOI' seismic exploration. 
These surveys, funded jointly by several industry groups, provided 
relatively sparse data on the distribution and abundance of marine 
mammals in nearshore waters of the Chukchi Sea, and the current 
distribution and densities of marine mammals there are unknown. 
Population sizes of several species found there may have changed 
considerably since earlier surveys were conducted and their 
distributions may have changed because of changes in ice conditions. 
SOI in cooperation with other industry groups, plans to conduct an 
aerial survey program in the Chukchi Sea in 2007 that will be similar 
to the 2006 program.
    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 are potential 
impacts 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 will be designed to collect distribution data on 
cetaceans and will be limited in its ability to collect similar data on 
pinnipeds.
    The aerial survey program will be conducted in support of the SOI 
seismic program in the Chukchi Sea during summer and fall of 2007. 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 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 nmi (37 km) offshore between Point 
Hope and Point Barrow will begin in early July and will continue 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 2007 field season, SOI will 
coordinate and cooperate with the aerial surveys conducted by 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.
    Three MMOs will be aboard the aircraft during surveys during key 
hunting periods. Two observers will be looking for marine mammals 
within 1 km (0.62 km) of the survey track line; one each at windows on 
either side of the aircraft. The third person will record data. When 
sightings are made, observers will notify the data recorder of the 
species or species class of the animal(s) sighted, the number of 
animals present, and the lateral distance (inclinometer angle) of the 
animals from the flight path of the aircraft. This information, along 
with time and location data from an onboard GPS, will be entered into a 
database. Environmental data that affect sighting conditions including 
wind speed, sea state, cloud cover or fog, and severity of glare will 
be recorded for each transect line or whenever conditions change 
substantially.

Acoustic ``Net'' Array: Chukchi Sea

    The acoustic ``net'' array used during the 2006 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 should they be detectable. If 
allowed by local villages, and equipment, ice and weather conditions 
permitting, an acoustic program in the Chukchi Sea from July-October 
will again be conducted.
    A suite of autonomous seafloor recorders will be deployed in the 
Chukchi Sea to collect acoustic data from strategically situated sites. 
Figure 5 in SOI's application shows the locations of the acoustic 
arrays in 2006. The 2007 program may be similar but may also modify the 
locations and types of recorders used to attempt to answer specific 
questions about the movement of bowhead whales through the Chukchi Sea 
during fall. The acoustic contractor will provide technical personnel 
support and equipment for the field deployment, refurbishment and 
recovery of recorders. The basic plan will be to deploy Acoustic 
recorders at strategic locations within the Chukchi Sea in locations 
where they can deliver broad area information on the acoustic 
environment of this basin. The specific geometries and placements of 
the arrays are primarily driven by the objectives of (a) detecting the 
occurrence and approximate offshore distributions of beluga and 
possibly bowhead whales during the July to mid-August period and 
primarily bowhead whales during the mid-August to late October period, 
(b) measuring ambient noise, and c) measuring received levels of 
seismic survey activities.

Acoustic ``Net'' Array: Beaufort Sea

    In addition to the continuation of the acoustic net array program 
in the Chukchi Sea in 2007, SOI plans to develop a similar acoustic 
component 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 vessel-based drilling 
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 possible 
alternative to aerial surveys 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. Also, acoustic methods 
require development and deployment of instruments that are stationary 
(preferably mounted on the bottom) to

[[Page 31567]]

record and localize the whale calls. However, acoustic methods would 
likely be more effective for studying impacts related to a stationary 
sound source, such as a drilling rig that is operating within a 
relatively localized area, than for a moving sound source such as that 
produced by a seismic source vessel.
    Bottom-founded acoustic recorders that have the ability to record 
calling whales will be deployed around SOI's seismic and drilling 
activities during the 2007 program. Figure 6 in SOI's application shows 
potential locations of the bottom-founded recorders and an array layout 
in relation to the proposed seismic and drilling locations. The actual 
locations of the bottom-founded recorders will depend on specifications 
of recording equipment chosen for the project, and on the acoustical 
characteristics of the environment. The results of these data will be 
used to determine the extent of deflection of migrating bowhead whales 
from the sound sources.

Reporting

Interim Report

    The results of the 2007 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 these technical report(s) 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.

Comprehensive Report

    Following the 2007 open water season a comprehensive report 
describing the proposed acoustic, vessel-based, and aerial monitoring 
programs will be prepared. The 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 2007. The report will form the basis for future monitoring 
efforts and will establish long term data sets to help evaluate changes 
in the Beaufort Sea ecosystem. 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 2007 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 MMS has begun consultation on the 
proposed seismic survey activities in the Beaufort and Chukchi seas 
during 2007. 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 noted 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 (71 FR 66912), NMFS and MMS announced that 
they were preparing a Draft PEIS. This PEIS is being prepared to assess 
the impacts of MMS' annual authorizations under the Outer Continental 
Shelf 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 (72 FR 15135), the Environmental Protection 
Agency (EPA) noted the availability for comment of the NMFS/MMS Draft 
PEIS and on April 6, 2007 (72 FR 17117), NMFS and MMS announced its 
availability and times and locations for public hearings. On May 11, 
2007 (72 FR 26788), based upon several verbal and written requests of 
additional time to review the Draft PEIS, NMFS announced an extension 
of the comment period until June 29, 2007. A copy of these NEPA 
documents are available upon request or online (see ADDRESSES).

Preliminary Conclusions

    Based on the information provided in SOI's application, this 
document, and the MMS Final PEA, NMFS has preliminarily determined that 
the impact of SOI conducting seismic surveys in the northern Chukchi 
Sea and eastern and central Beaufort Sea in 2007 will have no more than 
a negligible impact on marine mammals and that there will not be any 
unmitigable adverse impacts to subsistence communities, provided the 
mitigation measures described in this document are implemented (see 
Mitigation).
    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. In addition, no take by death and/

[[Page 31568]]

or serious injury is anticipated, and the potential for temporary or 
permanent hearing impairment 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.
    NMFS has preliminarily determined that the proposed seismic 
activity by SOI in the northern Chukchi Sea and central and eastern 
Beaufort Sea in 2007 will not have an unmitigable adverse impact on the 
subsistence uses of bowhead whales and other marine mammals. This 
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 15 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 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 2007, provided the 
previously mentioned mitigation, monitoring, and reporting requirements 
are incorporated. NMFS has preliminarily determined that the proposed 
activity would result in the harassment of only small numbers of marine 
mammals; would have no more than a negligible impact on the affected 
marine mammal stocks; and would not have an unmitigable adverse impact 
on the availability of species or stocks for subsistence uses.

    Dated: May 30, 2007.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. E7-10953 Filed 6-6-07; 8:45 am]
BILLING CODE 3510-22-S