Marine Mammals; Incidental Take During Specified Activities, 26770-26781 [06-4284]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 71, Number 88 (Monday, May 8, 2006)]
[Notices]
[Pages 26770-26781]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 06-4284]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service


Marine Mammals; Incidental Take During Specified Activities

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of receipt of applications and proposed incidental 
harassment authorization; request for comments.

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SUMMARY: The Fish and Wildlife Service (Service) has received requests 
from Shell Offshore, Inc. (Shell), ConocoPhillips Alaska, Inc. (CPAI), 
and GXT Houston (GXT) for authorizations to take small numbers of 
marine mammals by harassment incidental to conducting open-water 
seismic operations in the Chukchi Sea. In accordance with provisions of 
the Marine Mammal Protection Act (MMPA), as amended, the Service 
requests comments on its proposed authorization for the operators 
identified above to incidentally take, by harassment, small numbers of 
Pacific walrus and polar bears in the Chukchi Sea area between June 1, 
2006, and November 30, 2006.

DATES: Comments and information must be received by June 7, 2006.

ADDRESSES: You may submit comments by any of the following methods:
    1. By mail to: Craig Perham, Office of Marine Mammals Management, 
U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, Alaska 
99503.
    2. By fax to: 907-786-3816.
    3. By electronic mail (e-mail) to: FW7MMM@FWS.gov. Please submit 
comments as an ASCII file avoiding the use of special characters and 
any form of encryption. Please also include your name and return 
address in your

[[Page 26771]]

message. If you do not receive a confirmation from the system that we 
have received your message, contact us directly at U.S. Fish and 
Wildlife Service, Office of Marine Mammals Management, 907-786-3810 or 
1-800-362-5148.
    4. By hand-delivery to: Office of Marine Mammals Management, U.S. 
Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, AK 99503.
    5. Through the Federal E-rulemaking Portal at: https://
www.regulations.gov.

FOR FURTHER INFORMATION CONTACT: Craig Perham, Office of Marine Mammals 
Management, U.S. Fish and Wildlife Service, 1011 East Tudor Road, 
Anchorage, AK 99503; telephone 907-786-3810 or 1-800-362-5148; or e-
mail craig--perham@FWS.gov.

SUPPLEMENTARY INFORMATION:

Background

    Sections 101(a)(5)(A) and (D) of the MMPA, as amended, (16 U.S.C. 
1371 (a)(5)(A) and (D)) authorize the Secretary of the Interior to 
allow, upon request, the incidental, but not intentional, taking of 
small numbers of marine mammals by U.S. citizens who engage in a 
specified activity (other than commercial fishing) within a specified 
geographical region provided that 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 
and comment.
    Authorization to incidentally take marine mammals may be granted if 
the Service 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. 
Permissible methods of taking and other means of effecting the least 
practicable impact on the species or stock and its habitat, and 
requirements pertaining to the monitoring and reporting of such takings 
are prescribed as part of the authorization process.
    The term ``take,'' as defined by the MMPA, means to harass, hunt, 
capture, or kill, or attempt to harass, hunt, capture, or kill any 
marine mammal. Harassment, as defined by the MMPA, means ``any act of 
pursuit, torment, or annoyance which, (i) has the potential to injure a 
marine mammal or marine mammal stock in the wild [the MMPA calls this 
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 [the MMPA calls 
this Level B harassment].''
    The terms ``small numbers,'' ``negligible impact,'' and 
``unmitigable adverse impact'' are defined in 50 CFR 18.27, the 
Service's regulations governing take of small numbers of marine mammals 
incidental to specified activities. ``Small numbers'' is defined as ``a 
portion of a marine mammal species or stock whose taking would have a 
negligible impact on that species or stock.'' ``Negligible impact'' is 
defined 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.'' ``Unmitigable adverse impact'' is defined 
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.''
    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 where the take 
will be limited to harassment. Section 101(a)(5)(D)(iii) establishes a 
45-day time limit for Service review of an application followed by a 
30-day public notice and comment period on any proposed authorizations 
for the incidental harassment of marine mammals. Within 45 days of the 
close of the comment period, the Service must either issue or deny 
issuance of the authorization. The Service refers to these 
authorizations as Incidental Harassment Authorizations (IHAs).

Summary of Request

    On January 13, 2006, the Service received an application from Shell 
for the taking by harassment of Pacific walrus and polar bears 
incidental to conducting a seismic survey in the Chukchi Sea. Shell 
proposes to conduct a marine geophysical (deep seismic) survey program 
in support of future oil and gas exploration within the proposed 
Chukchi Sea Lease Sale 193. Leasing will occur in 2007. This activity 
is part of a comprehensive seismic program that includes conducting 
seismic operations in the Beaufort Sea as well. Incidental take 
authorization for the Beaufort Sea portion of Shell's program has been 
proposed under new regulations being proposed at 50 CFR part 18, 
subpart J (71 FR 14446; March 22, 2006). This overall seismic program 
is planned for the 2006 open-water season. Shell expects to conduct 
operations in the Chukchi Sea between July 15 and November 30, 2006. 
Scheduled transit time for Shell to the operational area is planned to 
begin June 15, 2006.
    On February 10, 2006, the Service received an application from CPAI 
for the taking by harassment of Pacific walrus and polar bears 
incidental to conducting a seismic survey in the Chukchi Sea. CPAI also 
plans to conduct a deep seismic survey program in support of future oil 
and gas exploration within the proposed Chukchi Sea Lease Sale 193. 
CPAI plans to operate their seismic program between July 1 and November 
30, 2006. Scheduled transit time for CPAI to the operational area is 
planned to begin June 1, 2006.
    On February 10, 2006, the Service also received an application from 
GXT for the taking by harassment of Pacific walrus and polar bears 
incidental to conducting a seismic survey program in the Chukchi Sea in 
support of oil and gas exploration. Their seismic program is scheduled 
to occur between July 1 and November 30, 2006. GXT's project area 
includes portions of the Lease Sale 193 area as well as areas outside 
the lease sale but, within the Chukchi Sea.
    All applicants are requesting authorization for incidental take by 
harassment of Pacific walrus and polar bear during seismic surveys 
occurring in various portions of the Chukchi Sea. Although the 
applicants' seismic survey programs have minor differences, such as in 
type (i.e., 2D and 3D), size of arrays, locations, timing, and support, 
the Service is consolidating the analysis of these separate requests 
because the activities are substantially the same in nature and the 
general area of operation requested by the applicants is identical. 
This also ensures that any overlapping of the effects of these programs 
will be identified and considered.

Description of the Activity

Shell Offshore, Inc.

    Shell and its geophysical (seismic) contractor WesternGeco propose 
to conduct a deep seismic survey program during the 2006 open-water 
season on various U.S. Minerals Management Service (MMS) Outer 
Continental Shelf (OCS) lease blocks in the Northern Chukchi Sea 
(within Lease Sale 193).

[[Page 26772]]

Shell is requesting an IHA for approximately 5.5 months (June 15 
through mid-to late-November 2006). This seismic program would consist 
of deep seismic surveys conducted from WesternGeco's vessel M/V Gilivar 
and supported by the M/V Kilabuk for resupply and fueling. The M/V 
Gilivar is also capable of assisting in ice management operations if 
needed, but will not deploy seismic acquisition gear.
    The general geographic region where the proposed deep seismic 
survey would occur is the Chukchi Sea MMS OCS Program Area designated 
as Chukchi Sea Lease Sale 193 and the proposed 2002-2007 Chukchi Sea 
Program Area. Shell has stated that, since the Chukchi deep seismic 
program would be conducted as a pre-lease activity, the exact locations 
where operations would occur remain confidential for business 
competitive reasons. Shell would use the seismic data acquired to 
determine what leases it would bid on in a forth-coming competitive 
lease sale. However, seismic acquisition would take place well offshore 
from the Alaska coast in OCS waters averaging greater than 40 meters 
(m) (130 feet [ft]) in depth.
    Shell has proposed two possible survey scenarios in an effort to 
maximize its opportunities to acquire seismic information in 2006. 
Scenario I involves conducting seismic operations in the Chukchi and 
Beaufort seas during the 2006 open-water season. Scenario II involves 
conducting seismic operations only in the Chukchi Sea during the 2006 
open-water season. Authorization for incidental take regarding the 
proposed seismic operations in the Beaufort Sea under Scenario I will 
be addressed in a separate request to the Service for a Letter of 
Authorization.
    Under Scenario I, deep seismic surveys in the Chukchi Sea would 
take place in two phases. Phase one would commence after June 15, 2006, 
as sea ice coverage conditions allow and would continue through July to 
early August 2006. Phase two of the Chukchi Sea deep seismic survey 
would occur after mid-October and continue until such time as sea ice 
and weather conditions preclude further work, probably sometime in mid-
to late-November 2006. Sea ice in this area is dynamic, therefore, the 
dates represent what might occur under ideal conditions for performing 
marine seismic work. The actual dates would depend on sea ice and 
weather conditions as they occur in summer and mid-autumn of 2006 and 
will not extend beyond the period identified here. Deep seismic data 
acquisition requires ice-free conditions for air gun and hydrophone 
streamer deployment and operation; thus both phases of the 2006 deep 
seismic program would have to occur during ice-free sea conditions. 
Also, the proposed commencement of the deep seismic survey would not 
occur earlier than June 15, 2006, even if marine conditions allow, 
since the timing is designed to ensure that there would be no conflict 
with the spring bowhead whale migration and the spring Chukchi 
subsistence hunts conducted by the Alaskan coastal villages of Point 
Hope, Wainwright, and Barrow.
    Under Scenario II, in the event that sea ice prevents travel to the 
Beaufort Sea area by early August, Shell would continue its seismic 
acquisition program through the entire open-water season in the Chukchi 
Sea (June 15 through mid-to late-November 2006). This scenario would 
approximately double the seismic line miles completed in the Chukchi 
Sea. Under Scenario I, approximately 5,556 kilometers (km) (3,000 
nautical miles [nm]) of seismic acquisition would occur in the Chukchi 
Sea, whereas under Scenario II, approximately 11,112 km (6,000 nm) of 
seismic line miles could be completed in the Chukchi Sea during the 
open-water season if operations in the Beaufort Sea were cancelled.
    Source arrays for the 3D survey would be composed of identically 
tuned Bolt gun sub-arrays operating at 2,000 pounds per square inch 
(psi) air pressure. 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 
cubic inches (in 3) sub-array is detailed in Shell's 
application and is composed of three sub-arrays comprising a total 
3,147 (in 3) sound source.

ConocoPhillips Alaska, Inc.

    CPAI is planning to conduct open-water seismic data acquisition in 
the Chukchi Sea during the 2006 open-water season. CPAI seeks an IHA 
for a period of 5 months (July 1 through November 30, 2006). 
Mobilization of operations will occur in mid-July, and seismic 
operations are proposed to begin in late July and end in November, 
depending on ice conditions.
    The scope of this application is limited to seismic exploration 
activities during the open-water season in Federal waters in the OCS of 
the Chukchi Sea, offshore Alaska. The geographic region of activity 
encompasses an area of 2,500 to 3,600 square (sq) km in the 
northeastern Chukchi Sea. The approximate boundaries of the region are 
within 158[deg]00' W and 169[deg]00' W and 69[deg]00' N and 73[deg]00' 
N, with the eastern boundary located parallel to the coast of Alaska, 
north of Point Hope to Point Barrow, and ranging 40-180 km off the 
coast. The nearest approximate point of the project to Point Hope is 74 
km, Point Lay 90 km, Wainwright 40 km, and Barrow 48 km. Water depths 
are typically less than 50 m.
    The goal of the project is to gather seismic data over 2,500 to 
3,600 sq km, weather and ice conditions permitting. CPAI anticipates 
approximately 90-100 days of work effort with about 30 percent downtime 
due to constraints, such as weather, ice conditions, and repairs. The 
operation would be active 24 hours per day. The seismic vessel 
currently planned for use is the M/V Patriot, owned by WesternGeco. In 
addition to the primary activity of the seismic vessel, there would be 
two support vessels. A supply vessel and a fuel bunkering vessel would 
be used to supply the seismic vessel. The seismic crew would change out 
by helicopter, and fixed-wing aircraft support may be used to assess 
ice conditions if necessary.
    The energy source for the proposed activity would be air gun array 
systems towed behind the vessel. There would be 6 to 8 cables 
approximately 4,000 m in length spaced 100 m apart. Each source array 
consists of identically tuned Bolt gun sub-arrays operating at 2,000 
psi air pressure. The arrays will fire on interleaved 50-m intervals 
that are designed to focus energy in a downward direction. Two air-gun 
arrays, each approximately 1,695 in 3 in size and spaced 
approximately 50 m apart, would be used. Together, the two arrays would 
be approximately 3,390 in 3 in size. The airgun array would 
fire approximately every 25 m as the vessel travels at 4 to 5 knots. 
The sub-array is composed of six tuning elements: two 2-gun clusters 
and four single guns. The clusters have component guns arranged in a 
fixed side-by-side fashion with the distance between the gun ports set 
to maximize the bubble suppression effects of clustered guns. A near-
field hydrophone is mounted about 1 m above each gun station (one phone 
is used per cluster), one depth transducer per position is mounted on 
the gun's ultrabox, and a high pressure transducer is mounted at the 
aft end of the sub-array to monitor high pressure air supply. All data 
from the sensors are transmitted to the vessel for input into the 
onboard systems and recording to tape.

[[Page 26773]]

GXT Corporation

    GXT will conduct a marine seismic survey in the area of the MMS 
Lease Sale 193 in the Chukchi Sea. GXT expects the seismic vessel M/V 
Discoverer II to arrive at Dutch Harbor, Alaska, on or about June 15, 
2006, for crew change and re-supply. Depending on ice conditions in the 
Chukchi Sea, the vessel would mobilize to arrive off Cape Lisburne and 
begin seismic acquisition as soon as possible. The expected starting 
date is on or about July 1, 2006.
    There are two scenarios being planned dependant upon the seasonal 
ice conditions encountered in 2006. The primary scenario (and most 
expected) entails operations beginning in the Chukchi Sea until passage 
along the Beaufort Sea opens enough to allow seismic acquisition across 
the entire coast. The vessel would then proceed out of the Chukchi and 
begin operations within the Beaufort Sea area. Seismic acquisition 
could begin as early as July 21. The vessel would continue operations 
until all data are collected, or the new ice begins forming in the 
fall. It is then expected that the vessel would exit the Beaufort and 
complete any lines left in the Chukchi Sea until either the program is 
complete or weather and sea ice preclude further work. The open-water 
season is not expected to extend past November 30, 2006.
    The second scenario would be enacted only if the sea ice does not 
move offshore in the Beaufort Sea and adequate areas of open water do 
not exist to allow collection of seismic data in the planned area. In 
that case, the vessel would continue operations in the Chukchi Sea 
until all programmed lines are collected. The vessel would then exit 
the area and transits to Dutch Harbor to demobilize.
    GXT will gather data in the Chukchi Sea with the use of ultra-deep 
2D lines that oil and gas companies use to better evaluate the 
evolution of the petroleum system at the basin-level, including 
identifying source rocks, migration pathways, and play types. In many 
cases, the availability of geoscience data will extend beyond seismic 
information to include magnetic, gravity, well log, and electromagnetic 
information, helping to illustrate the most comprehensive picture of 
the subsurface as possible.
    The 2D data will be collected utilizing a towed, single streamer up 
to 9,000 m in length along with an airgun array towed directly behind a 
single vessel. The source vessel will tow a 40 G. gun array with a 
total discharge volume of 3,980 in\3\ along predetermined lines. The 
airgun array is discharged on a periodic basis and the streamer records 
the reflected sound waves. Since the goal is to record data from deep 
in the subsurface, the recording period runs from 15 to 18 seconds, 
depending on the area, with the airgun array being discharged 
approximately every 20 seconds. The array will be towed at 
approximately 50 m from the stern of the Discoverer II at a depth of 
approximately 8.5 m. As the airgun array is towed along the survey 
line, the towed hydrophone array receives the reflected signals and 
transfers the data to the on-board processing system. The 40 G. gun 
array will consist of 48 G. guns (24 x 2-G. gun pairs). Eight of those 
guns will not be activated but, will be included in the array and 
available as spare guns.
    The vessel will proceed down a pre-plotted line collecting the data 
on a continuous basis until the required line is complete. Several 
segments of the single line may be required due to instrument failure, 
weather, or any other interruption that may occur. The grid of lines 
proposed by the applicant covers the entire Chukchi Sea area and ties 
together known wells, core locations, fault lines, and other 
geophysical points of interest.
    The GXT seismic program will consist of 14 lines totaling 5,793 km 
(3,570 statute miles) of data acquisition for the Chukchi Sea area. The 
program will be based on a large grid of lines orientated to connect 
previous well locations, core sample locations, and geological 
structures in the sub-surface. Lines will be chosen based on factors 
such as, subsistence hunting, ice movement, and areas of geophysical 
importance. It is anticipated that all lines would be acquired under 
either of the two scenarios proposed. There is no plan to add mileage 
to this total, so the season would be complete for the Chukchi region 
when all 14 lines have been acquired.

Description of Habitat, Marine Mammals Affected by the Activity, and 
the Impact on Affected Marine Mammals

    The geographic area covered by the request is the OCS of the 
Chukchi Sea adjacent to western Alaska. This area includes the waters 
and seabed of the Chukchi Sea, which encompasses all waters north of 
the Bering Strait that are east of the U.S.-Russia Convention Line of 
1807, west of a north-south line at Point Barrow, and within 200 miles 
to the north of Point Barrow. This delineation of the Chukchi Sea 
includes the Chukchi Seas Lease Sale 193, scheduled for leasing in 
2007.

Biological Information

Pacific Walrus

Stock Definition and Range
    The Pacific walrus (Odobenus rosmarus divergens) is represented by 
a single stock of animals that inhabits the shallow continental shelf 
waters of the Bering and Chukchi seas. The population ranges across the 
international boundaries of the United States and Russia, and both 
nations share common interests with respect to the conservation and 
management of this species.
    The distribution of Pacific walrus varies markedly with the 
seasons. During the late winter breeding season, walrus are found in 
areas of the Bering Sea where open leads, polynas, or areas of broken 
pack-ice occur. Significant winter concentrations are normally found in 
the Gulf of Anadyr, the St. Lawrence Island Polyna, and in an area 
south of Nunivak Island. In the spring and early summer, most of the 
population follows the retreating pack-ice northward into the Chukchi 
Sea; however, several thousand animals, primarily adult males, remain 
in the Bering Sea, utilizing coastal haulouts during the ice-free 
season. During the summer months, walrus are widely distributed across 
the shallow continental shelf waters of the Chukchi Sea. Significant 
summer concentrations are normally found in the unconsolidated pack-ice 
west of Point Barrow, and along the northern coastline of Chukotka in 
the vicinity of Wrangel Island. As the ice edge advances southward in 
the fall, walrus reverse their migration and re-group on the Bering Sea 
pack-ice.
Population Status
    Several decades of intense commercial exploitation in the late 
1800s and early 1900s left the population severely depleted. Fay et al. 
(1997) reviewed the results of aerial surveys conducted between 1960 
and 1985 and concluded that the population had increased from 50,000-
100,000 animals in the late 1950s to more than 250,000 animals by 1985. 
They attributed this rapid population growth to hunting restrictions 
enacted in the United States and Russia that reduced the size of the 
commercial harvest and provided protection to female walrus and calves. 
Information concerning population size and trend after 1985 is less 
certain. An aerial survey flown in 1990 produced a population estimate 
of 201,039 animals; however, large confidence intervals associated with 
that estimate precluded any conclusions

[[Page 26774]]

concerning population trend (Gilbert et al. 1992). The current size and 
trend of the Pacific walrus population are unknown, but the 1990 figure 
is considered conservative. In 2006, the Service and USGS, in 
partnership with Russian scientists, will conduct a range-wide survey 
to estimate population size.
Habitat and Prey
    Walrus rely on floating pack-ice as a substrate for resting and 
giving birth. Walrus generally require ice thicknesses of 50 
centimeters (cm) or more to support their weight. Although walrus can 
break through ice up to 20 cm thick, they usually occupy areas with 
natural openings and are not found in areas of extensive, unbroken ice. 
Thus, their concentrations in winter tend to be in areas of divergent 
ice flow or along the margins of persistent polynas. Concentrations in 
summer tend to be in areas of unconsolidated pack-ice, usually within 
100 km of the leading edge of the ice pack. The juxtaposition of ice 
over appropriate depths for feeding is especially important for female 
walrus with dependent young that may not be capable of deep diving or 
of long-term exposure in the water. Walrus resting on the ice are 
passively transported to other feeding areas, which may help to prevent 
local depletions of their prey resource.
    When suitable pack-ice is not available, walrus haul out to rest on 
land. Isolated sites, such as barrier islands, points, and headlands, 
are most frequently occupied. Social factors, learned behavior, and 
proximity to their prey base are also thought to influence the location 
of haulout sites. Traditional walrus haulout sites in the eastern 
Chukchi Sea include Cape Thompson, Cape Lisburne and Icy Cape. In 
recent years, the Cape Lisburne haulout site has seen regular use in 
late summer. Numerous haulouts exist along the northern coastline of 
Chukotka, including Wrangel and Herald islands, which are considered 
important hauling grounds in September, especially in years when the 
pack-ice retreats far to the north.
    Although capable of diving to deeper depths, walrus are for the 
most part found in shallow waters of 100 m or less, possibly because of 
higher productivity of their benthic foods in shallower water. They 
feed almost exclusively on benthic invertebrates although Native 
hunters have also reported incidences of walrus preying on seals. Prey 
densities are thought to vary across the continental shelf according to 
sediment type and structure. Preferred feeding areas are typically 
composed of sediments of soft, fine sands. Foraging trips may last for 
several days, during which time they dive to the bottom nearly 
continuously. Most foraging dives to the bottom last between 5 and 10 
minutes, with a relatively short (1-2 minute) surface interval. The 
intensive tilling of the sea floor by foraging walrus is thought to 
have significant influence on the ecology of the Bering and Chukchi 
Seas. Foraging activity recycles large quantities of nutrients from the 
sea floor back into the water column, provides food for scavenger 
organisms, and contributes greatly to the diversity of the benthic 
community.
Life History
    Walrus are long-lived animals with low rates of reproduction. 
Females reach sexual maturity at 4-9 years of age. Males become fertile 
at 5-7 years of age; however, they are usually unable to compete for 
mates until they reach full physical maturity at 15-16 years of age. 
Breeding occurs between January and March in the pack-ice of the Bering 
Sea. Calves are usually born in late April or May the following year 
during the northward migration from the Bering Sea to the Chukchi Sea. 
Calves are capable of entering the water shortly after birth, but tend 
to haulout frequently, until their swimming ability and blubber layer 
are well developed. Calves weigh about 63 kg (139 lb) at birth. Walrus 
calves accompany their mother from birth and are usually not weaned for 
2 years or more. Females with newborn young often join together to form 
large nursery herds. Summer distribution of females and young walrus is 
closely tied to the movements of the pack-ice relative to feeding 
areas. Females give birth to one calf every two or more years. This 
reproductive rate is much lower than other pinnipeds; however, some 
walrus may live to age 35-40 and remain reproductively active until 
relatively late in life.
    Walrus are extremely social and gregarious animals. They tend to 
travel in groups and haulout onto ice or land in groups. Walrus spend 
approximately one-third of their time hauled out onto land or ice. 
Hauled-out walrus tend to lie in close physical contact with each 
other. Youngsters often lie on top of the adults. The size of the 
hauled out groups can range from a few animals up to several thousand 
individuals.
Mortality
    Polar bears (Ursus maritimus) are known to prey on walrus calves, 
and killer whales (Orcinus orca) have been known to take all age 
classes of animals. Predation levels are thought to be highest near 
terrestrial haulout sites where large aggregations of walrus can be 
found; however, few observations exist for off-shore environs.
    Pacific walrus have been hunted by coastal Natives in Alaska and 
Chukotka for thousands of years. Exploitation of walrus by Europeans 
has also occurred in varying degrees since first contact. Presently, 
walrus hunting in Alaska and Chukotka is restricted to meet the 
subsistence needs of aboriginal peoples. The Service, in partnership 
with the Eskimo Walrus Commission (EWC) and the Association of 
Traditional Marine Mammal Hunters of Chukotka, administers subsistence 
harvest monitoring programs in Alaska and Chukotka. Harvest mortality 
over the past 5 years (2000-2005) is estimated at 5,458 walrus per year 
(Table 1). This mortality estimate includes corrections for under-
reported harvest and struck and lost animals.
    Intraspecific trauma is also a known source of injury and 
mortality. Disturbance events can cause walrus to stampede into the 
water and have been known to result in injuries and mortalities. The 
risk of stampede-related injuries increases with the number of animals 
hauled out. Calves and young animals at the perimeter of these herds 
are particularly vulnerable to trampling injuries.

                   Table 1.--Total Corrected Subsistence Harvest of Pacific Walrus, 2001-2005
----------------------------------------------------------------------------------------------------------------
                                                     Reported                                          Total
                      Year                            Russia       Reported U.S.  Total reported     corrected
                                                      harvest        harvest*         harvest        harvest**
----------------------------------------------------------------------------------------------------------------
2001............................................           1,332           1,843           3,175           5,474
2002............................................           1,317           2,236           3,553           6,126
2003............................................           1,425           2,175           3,600           6,207
2004............................................           1,118           1,481           2,599           4,481
2005............................................           1,470           1,430           2,900           5,000

[[Page 26775]]

 
Mean 2001-2005..................................           1,332           1,833           3,165          5,458
----------------------------------------------------------------------------------------------------------------
* Corrected for non-compliance with the Marking, Tagging, and Reporting Program.
** Total corrected harvest = total reported harvest + 42 percent struck and lost (mortally wounded but not
  recovered).

Distributions and Abundance in the Chukchi Sea and Lease Sale 193 Area
    Walrus are seasonably abundant in the Chukchi Sea and Lease Sale 
193 Area. Their distribution is largely influenced by the extent of the 
seasonal pack-ice. In May and June, most of the population migrates 
through the Bering Strait into the Chukchi Sea. Walrus tend to migrate 
into the Lease Sale Area along lead systems that develop along the 
northwest coast of Alaska. Walrus are expected to be closely associated 
with the southern edge of the seasonal pack-ice during the proposed 
operating season. By July, large groups of walrus, up to several 
thousand animals, can be found along the edge of the pack-ice between 
Icy Cape and Point Barrow. During August, the edge of the pack-ice 
generally retreats northward to about 71[deg]N, but in light ice years, 
the ice edge may retreat beyond 76[deg]N. The sea ice normally reaches 
its minimum (northern) extent in September. It is unclear how walrus 
respond in years when the sea ice retreats beyond the relatively 
shallow continental shelf waters. At least some animals are thought to 
migrate west towards Chukotka, while others have been observed hauling 
out along the shoreline between Point Barrow and Cape Lisburne. The 
pack-ice rapidly advances southward in October, and most animals are 
thought to have returned to the Bering Sea by early November.
    A recent abundance estimate for the number of walrus present in the 
Chukchi Sea, including the Lease Sale 193 Area during the proposed 
operating season is lacking. Johnson et al. (1980) estimated 101,213 
walrus hauled-out onto Chukchi Sea pack-ice, east of 172[deg]30' W, in 
September 1980. Gilbert (1989) estimated 62,177 walrus were distributed 
in the Chukchi Sea pack-ice in the eastern Chukchi Sea in September 
1985. Gilbert et al. (1992) estimated 16,489 walrus were distributed in 
the Chukchi sea pack-ice between Wrangel Island and Point Barrow in 
September 1990, but the authors also noted that the pack-ice was 
distributed well beyond the continental shelf at the time of the 
survey. These abundance estimates are all considered conservative 
because no corrections were made for walrus in water (not visible) at 
the time of the surveys.

Polar Bear

Stock Definition and Range
    Polar bears occur throughout the Arctic. In Alaska, they have been 
observed as far south in the eastern Bering Sea as St. Matthew Island 
and the Pribilof Islands, but they are most commonly found within 180 
miles of the Alaskan coast of the Chukchi and Beaufort Seas, from the 
Bering Strait to the Canadian border. Two stocks occur in Alaska: (1) 
The Bering-Chukchi Seas stock; and (2) the Southern Beaufort Sea stock. 
The Chukchi/Bering seas stock is defined as polar bears inhabiting the 
area as far west as the eastern portion of the Eastern Siberian Sea, as 
far east as Point Barrow, and extending into the Bering Sea, with its 
southern boundary determined by the extent of annual ice. The world 
population estimate of polar bears ranges from 20,000-25,000 
individuals (International Union for the Conservation of Nature and 
Natural Resources 2006). The Southern Beaufort Sea stock estimate is 
2,200 animals. Previous population estimates have put the Chukchi/
Bering sea population at 2,000 to 5,000; however, currently, a reliable 
population estimate is not available for the Bering-Chukchi Sea polar 
bear stock.
Habitat
    Polar bears of the Chukchi Sea are subject to the movements and 
coverage of the pack-ice. The most extensive north-south movements of 
polar bears are associated with the spring and fall ice movement. For 
example, during the 2006 ice-covered season, numerous bears radio-
collared in the Beaufort Sea were located in the Chukchi and Bering 
Seas as far south as 59[deg] latitude. Summer movements tend to be less 
dramatic due to the reduction of ice habitat. Summer distribution is 
somewhat dependent upon the location of the ice front; however, polar 
bears are accomplished swimmers and are often seen on floes separated 
from the main pack-ice. Therefore, bears can appear at any time in what 
can be called ``open water.'' The summer ice pack can be quite disjunct 
and segments can be driven by wind great distances carrying polar bears 
with them. Bears from both stocks overlap in their distribution around 
Point Barrow and can move into surrounding areas depending on ice 
conditions.
    Polar bears spend most of their time in nearshore, shallow waters 
over the productive continental shelf associated with the shear zone 
and the active ice adjacent to the shear zone. Sea ice and food 
availability are two important factors affecting the distribution of 
polar bears.
Denning and Reproduction
    Although insufficient data exist to accurately quantify polar bear 
denning along the Alaskan Chukchi Sea coast, dens in the area are less 
concentrated than for other areas in the Arctic. The majority of 
denning of Chukchi Sea polar bears occurs on Wrangel Island, Herald 
Island, and certain locations on the northern Chukotka coast. Females 
without dependent cubs breed in the spring. Females can initiate 
breeding at 5 to 6 years of age. Females with cubs do not mate. 
Pregnant females enter maternity dens by late November, and the young 
are usually born in late December or early January. Only pregnant 
females den for an extended period during the winter; other polar bears 
may excavate temporary dens to escape harsh winter winds. An average of 
two cubs are usually born, and after giving birth, the female and her 
cubs remain in the den where the cubs are nurtured until they can walk. 
Reproductive potential (intrinsic rate of increase) is low. The average 
reproductive interval for a polar bear is 3 to 4 years, and a female 
polar bear may produce about 8 to 10 cubs in her lifetime; 50 to 60 
percent of the cubs will survive. Female bears can be quite sensitive 
to disturbances during this denning period.
    In late March or early April, the female and cubs emerge from the 
den. If the mother moves young cubs from the den before they can walk 
or withstand the cold, mortality to the cubs may increase. Therefore, 
it is thought that successful denning, birthing, and rearing activities 
require a relatively

[[Page 26776]]

undisturbed environment. Radio and satellite telemetry studies 
elsewhere indicate that denning can occur in multi-year pack-ice and on 
land.
Prey
    Greater than 90 percent of a polar bear's diet is ringed seals 
(Phoca hispida). Bearded seals (Erignathus barbatus) and walrus calves 
are hunted occasionally. Polar bears opportunistically scavenge marine 
mammal carcasses, and there are reports of polar bears killing beluga 
whales (Delphinapterus leucas) trapped in the ice. Polar bears are also 
known to eat nonfood items including styrofoam, plastic, antifreeze, 
and hydraulic and lubricating fluids.
    Polar bears hunt seals along leads and other areas of open water, 
or by waiting at a breathing hole, or by breaking through the roof of a 
seal's lair. Lairs are excavated in snow drifts on top of the ice. 
Bears also stalk seals in the spring when they haul out on the ice in 
warm weather. The relationship between ice type and bear distribution 
is as yet unknown, but it is suspected to be related to seal 
availability.
Life History
    Both fur and fat are important to polar bears for insulation in air 
and water. Cubs-of-the-year must accumulate a sufficient layer of fat 
in order to maintain their body temperature when immersed in water. It 
is unknown to what extent young cubs can withstand exposure in water 
before they are threatened by hypothermia. Polar bears groom their fur 
to maintain its insulative value. Polar bears are long-lived (up to 30 
years) and have no natural predators, and they do not appear to be 
prone to death by diseases or parasites. Cannibalism by adult males on 
cubs and occasionally on other bears is known to occur.
Mortality
    The most significant source of mortality is man. Before the MMPA 
was passed in 1972, polar bears were taken by sport hunters and 
residents. Between 1925 and 1972, the mean reported kill was 186 bears 
per year. Seventy-five percent of these were males, as cubs and females 
with cubs were protected. Since 1972, only Alaska Natives have been 
allowed to hunt polar bears for their subsistence uses or for 
handicraft and clothing items for sale. The Native hunt occurs without 
restrictions on sex, age, or number provided that the population is not 
determined to be depleted. From 1980 to 2005, the total annual harvest 
for Alaska averaged 101 bears: 64 percent from the Chukchi Sea and 36 
percent from the Beaufort Sea. Barrow, Point Hope, Point Lay, and 
Wainwright are communities within the area potentially affected by 
seismic activities. The total harvest of bears by these communities 
during the 10-year period of 1995 to 2005 was as follows: Barrow (228 
bears), Point Hope (136 bears), Point Lay (25 bears), and Wainwright 
(77 bears). Table 2 provides long-term and annual data on polar bear 
harvests for the villages within the area. Bears are generally 
harvested between the months of January to May, with May the month when 
most bears are harvested. Annually, the lowest numbers of polar bears 
are harvested between June and September.

                  Table 2.--Native Subsistence Polar Bear Harvest Estimates by Year and Village
----------------------------------------------------------------------------------------------------------------
              Village                1988-1999    2000/2001    2001/2002    2002/2003    2003/2004    2004/2005
----------------------------------------------------------------------------------------------------------------
Barrow............................          238           28           25           25           20           10
Wainwright........................           88           10            2            5           13            5
Point Lay.........................           21            1            1            1            3            4
Point Hope........................          155           15            9           12           10           9
----------------------------------------------------------------------------------------------------------------
Based upon USFWS polar bear harvest data. Harvest year extends from July 1 to June 30.

Potential Impacts of Operations and Associated Activities on Marine 
Mammals

Pacific Walrus

    Seismic exploration activities in the Chukchi Sea have the 
potential to impact walrus in a number of ways. Air and vessel traffic 
may cause herds to stampede. Noise from air traffic, seismic surveys, 
icebreakers, and supply ships may displace individuals and herds. The 
quantity and quality of walrus prey could be affected by contamination 
of the benthos from operational petroleum spills.
    Disturbances caused by vessel and air traffic may cause walrus 
groups to abandon land or ice haulouts. Severe disturbance events could 
result in trampling injuries or cow-calf separations, both of which are 
potentially fatal.
    Open-water seismic exploration produces underwater sounds, 
typically with airgun arrays. Although the hearing sensitivity of 
walrus is poorly known, some source levels are thought to be high 
enough to cause temporary hearing loss in other species of pinnipeds. 
Therefore, it is possible that walrus within the 190-decibel (dB re 1 
[mu]Pa) safety radius sound cone of seismic activities (Industry 
standard safety criterion for seals, which operates as the limit for 
potential injury) could suffer temporary shifts in hearing threshold 
and temporary hearing loss. Conversely, the 160-decibel (dB re 1 
[mu]Pa) sound level is the limit of assumed behavioral harassment where 
animals may react to the sound source by avoiding the area.
    Noise from air traffic, vessel traffic, and seismic operations 
resulting in harassment has the potential to disturb or displace walrus 
up to several kilometers from the sound source. Potential effects of 
prolonged or repeated disturbances include displacement from preferred 
feeding areas, increased stress levels, increased energy expenditure, 
masking of communication, and the impairment of thermoregulation of 
neonates that spend too much time in the water.
    The response of walrus to noise disturbance stimuli is highly 
variable, from avoidance to tolerance. Studies have shown that 
pinnipeds appear to be less responsive to noise than other marine 
mammals. Anecdotal observations by walrus hunters and researchers 
suggest that males tend to be more tolerant of disturbances than 
females and individuals tend to be more tolerant than groups. Females 
with dependent calves are considered least tolerant of disturbances. 
Walrus in the water are thought to be more tolerant to disturbance 
stimuli than those hauled out.
    Quantitative research on the sensitivity of walrus to noise has 
been limited because no audiograms (a test to determine the range of 
frequencies and minimum hearing threshold) have been done on walrus. 
Hearing sensitivity is assumed to be within the 13 Hz and 1,200 Hz 
range of their own vocalizations. Walrus hunters and researchers have 
also noted that walrus tend to react to the presence of humans

[[Page 26777]]

and machines at greater distances from upwind approaches than from 
downwind approaches, suggesting that odor may also be a stimulus for a 
flight response. The visual acuity of walrus is thought to be less than 
for other species of pinnipeds.
    Reactions to aircraft are thought to vary with aircraft type, 
range, and flight pattern, as well as walrus age, sex, and group size. 
Fixed-winged aircraft are less likely to elicit a response than 
helicopter overflights. Walrus are particularly sensitive to changes in 
engine noise and are more likely to stampede when planes turn or fly 
low overhead. Researchers conducting aerial surveys for walrus in sea 
ice habitats have observed little reaction to aircrafts above 1,000 ft 
(305 m).
    The reaction of walrus to vessel traffic appears to be dependent 
upon vessel type, distance, speed, and previous exposure to 
disturbances. Underwater noise from vessel traffic in the Chukchi Sea 
may ``mask'' ordinary communication between individuals. Other factors, 
such as weather and length of time hauled out, may also contribute to 
the response. Ice management operations are expected to have the 
greatest potential for disturbances since these operations typically 
require the vessel to accelerate, reverse direction, and turn rapidly, 
activities that maximize propeller cavitation and resulting noise 
levels. However, researchers on board an icebreaker during ice 
management operations observed little to no reaction of hauled-out 
walrus groups beyond 0.5 mile (800 m). Furthermore, ship-board 
monitoring and mitigation measures for ice management, such as ``ice 
scouting,'' will indirectly limit encounters between vessels and walrus 
hauled out on ice floes.
    Seismic operations are expected to create significantly more noise 
than general vessel and icebreaker traffic; however, there are no data 
available to evaluate the potential response of walrus to seismic 
operations. Studies in the Beaufort Sea based on visual monitoring from 
seismic vessels show that pinnipeds exhibit minimal avoidance of 
airguns, and slight changes in behavior. These studies show that 
pinnipeds frequently do not avoid the area within a few hundred meters 
of an operating airgun array. However, visual studies have their 
limitations and initial work suggests that avoidance and other 
behavioral reactions may be stronger than evident to date from visual 
studies.
    For the purpose of this IHA, the Service will consider sound levels 
greater than 160 dB as the criterion for the onset of behavioral 
harassment, which is based on criteria developed for other pinniped 
species. Marine mammal monitoring programs are expected to provide 
further insight to the response of walrus to various seismic operations 
from which future mitigative conditions can be developed.

Polar Bear

    Seismic exploration activities in the Chukchi Sea may affect polar 
bears in a number of ways. Seismic ships and icebreakers may be 
physical obstructions to polar bear movements, although these impacts 
are of short-term and localized effect. Noise, sights, and smells 
produced by exploration activities may repel or attract bears, either 
disrupting their natural behavior or endangering them by threatening 
the safety of seismic personnel.
    Little research has been conducted on the effects of noise on polar 
bears. Polar bears are curious and tend to investigate novel sights, 
smells, and possibly noises. Noise produced by seismic activities could 
elicit several different responses in polar bears. Noise may act as a 
deterrent to bears entering the area of operation, or noise could 
potentially attract curious bears. Underwater noises produced by 
exploration are probably not a relevant form of disturbance because 
bears spend most of their time on the ice or at the surface of the 
water. Polar bears normally swim with their heads above the surface, 
where underwater noises are weak or undetectable. Polar bears are known 
to run from sources of noise and the sight of vessels or icebreakers 
and aircraft, especially helicopters. The effects of fleeing from 
aircraft may be minimal if the event is short and the animal is 
otherwise unstressed. On a warm spring or summer day, a short run may 
be enough to overheat a well-insulated polar bear. Likewise, fleeing 
from a working icebreaker may have minimal effects for a healthy animal 
on a cool day.
    In the Chukchi Sea, during the open-water season, polar bears spend 
the majority of their time on pack-ice, which limits the chance of 
impacts from human and industry activities. Occasionally, polar bears 
can be found in open water, miles from the ice edge or ice floes.
    Vessel traffic could result in short-term behavioral disturbance to 
polar bears. During the open-water season, most polar bears remain 
offshore in the pack-ice and are not typically present in the area of 
vessel traffic. If a ship is surrounded by ice, it is more likely that 
curious bears will approach. Any on-ice activities required by 
exploration activities create the opportunity for bear'human 
interactions. In relatively ice-free waters, polar bears are less 
likely to approach ships, although bears may be encountered on ice 
floes. For example, during the late 1980s, at the Belcher exploration 
drilling site in the Beaufort Sea, in a period of little ice, a large 
floe threatened the drill rig at the site. After the floe was moved by 
an icebreaker, workers noticed a female bear with a cub-of-the-year and 
a lone adult swimming nearby. It was assumed these bears had been 
disturbed from the ice floe.
    Ships and icebreakers may act as physical obstructions in the 
spring during the start-up period for exploration if they transit 
through a restricted lead system, such as the Chukchi Polynya. Polynyas 
are important habitat for marine mammals, which makes them important 
hunting areas for polar bears. Ship traffic in these ice conditions may 
intercept or alter movements of bears. A similar situation could occur 
in the fall when the pack-ice begins to expand.
    Routine aircraft traffic should have little to no effect on polar 
bears; however, extensive or repeated overflights of fixed-wing 
aircraft or helicopters could disturb polar bears. Behavioral reactions 
of polar bears should be limited to short-term changes in behavior that 
would have no long-term impact on individuals and no impacts on the 
polar bear population.

Potential Impacts on Subsistence Needs

Pacific Walrus

    Pacific walrus are a valuable subsistence resource utilized by 
coastal Alaska Natives. For thousands of years, walrus hunting has been 
an important source of food and raw materials for equipment and 
handicrafts. Today, walrus hunting remains an important part of the 
culture and economy of many coastal villages in Alaska. The communities 
most likely to be impacted by the proposed activities are Point Hope, 
Point Lay, Wainwright, and Barrow.
    Point Hope hunters typically begin their hunt in late May and June 
as walrus migrate north into the Lease Sale 193 Area. The sea ice is 
usually well off shore of Point Hope by July and does not bring animals 
back into the range of hunters until late August and September. Between 
2000 and 2006, the average annual reported harvest at Point Hope was 11 
animals per year (Table 3).
    Walrus hunting in Point Lay occurs primarily in July. Point Lay 
hunters reported an average of 6.2 walrus per year between 2000 and 
2004 (Table 3).

[[Page 26778]]

    Wainwright residents hunt walrus from June through August as the 
ice retreats northward. Walrus are plentiful in the pack-ice near the 
village this time of year. Wainwright hunters have consistently 
harvested more walrus than any other subsistence community on the North 
Slope. The village averaged 62.2 animals per year for 2000-2004 (Table 
3).
    Barrow is the northernmost community near the project area. Most 
walrus hunting occurs from June through September, peaking in August, 
when the land-fast ice breaks up and hunters can access the walrus by 
boat as they migrate north on the retreating pack-ice. The average 
annual walrus harvest for Barrow from 2000 to 2004 was 31.8 animals 
(Table 3).

                    Table 3.--Native Subsistence Walrus Harvest Estimates by Year and Village
----------------------------------------------------------------------------------------------------------------
              Village                1988-1999       2000         2001         2002         2003         2004
----------------------------------------------------------------------------------------------------------------
Barrow............................          228           19           36           39           51           14
Wainwright........................          508           36           93          118           29           35
Point Lay.........................           31            6            3           10           10            2
Point Hope........................           36            6            2           15           12          20
----------------------------------------------------------------------------------------------------------------
Based upon walrus reported through the USFWS Marking, Tagging, and Reporting Program. Walrus harvest data for
  2005 is not presently available. Harvest totals are not corrected for struck and lost animals.

    Any activity that displaces walrus beyond the range of coastal 
hunters has the potential to adversely impact subsistence harvests in 
these communities. Walrus hunting may occur anywhere along the Chukchi 
Sea coastline from Cape Lisburne to Point Barrow. Walrus hunting from 
these communities is generally limited to conditions when sea ice 
occurs within the range of small hunting boats, typically less than 30 
miles from shore.
    Little information is available to predict the effects of offshore 
activities on subsistence walrus hunting; however, walrus hunting 
occurs primarily in pack-ice and it is unlikely that open-water seismic 
activities would have a significant impact on subsistence harvest 
opportunities. As described in the section on standard operational 
conditions, the Service will require Shell, CPAI, and GXT to consult 
with affected communities and the EWC, as appropriate, to identify 
measures to minimize any potential impact to subsistence hunters in the 
affected communities.

Polar Bear

    Depending upon ice conditions, the subsistence harvest of polar 
bears can occur year-round in the northern Chukchi Sea villages, with 
peaks in the spring and winter. The period with the lowest harvest of 
bears occurs in June and July. Hunting success varies considerably from 
year to year because of variable ice and weather conditions.
    Little information is available for predicting the effects of 
offshore activities on subsistence polar bear hunting in the Chukchi 
Sea; however, direct conflicts are unlikely to occur between polar bear 
hunters and seismic activities because the timing of polar bear hunting 
occurs primarily during the winter and spring when pack-ice is present 
nearshore and the seismic activities will occur in the summer and fall 
open-water seasons. As described in the section on standard operational 
conditions, the Service will require Shell, CPAI, and GXT to consult 
with affected communities, as appropriate, to identify measures to be 
taken to minimize any potential impact to subsistence hunters in the 
affected communities.

Basis for Findings

Negligible Impact on Species

    Our findings of negligible impact were based on the total level of 
activity described by each applicant and the Service's analysis of the 
effects of all activities. In making this finding, we considered the 
following: (1) The distribution of the species; (2) the biological 
characteristics of the species; (3) the nature of seismic programs; (4) 
the potential effects of seismic programs on the species; and (5) the 
documented impacts of seismic activities on the species.
    Vessels associated with seismic activities plan to travel in open 
water to avoid ice floes, which is where walrus are likely to be found. 
Furthermore, walrus are not uniformly distributed across the proposed 
study area. The proposed seismic operations would not be concentrated 
in any location for extended periods. Therefore, most of the proposed 
activities would occur in areas of open water where walrus densities 
are expected to be relatively low. Based on the proposed activities and 
the distribution of walrus, we find that takes are likely to be limited 
to harassment of a relatively small number of animals and of relatively 
short-term in duration. Therefore, the proposed activities are not 
reasonably likely to adversely affect the Pacific walrus or the Pacific 
walrus stock through effects on annual rates of recruitment or 
survival.
    The number of polar bears present in the open water of the Chukchi 
Sea during the time of seismic activity will also be minimal. 
Individual polar bears may be observed in the open water during seismic 
activities, but the majority of the population will be found on the 
pack-ice during this time of year and, again, seismic activities avoid 
ice floes and the pack-ice edge. The Service anticipates that potential 
impacts of seismic activities on polar bears would be limited to short-
term changes in behavior and would have no long-term impact on 
individuals or impacts to the polar bear population. Therefore, we find 
that the proposed seismic activities are not reasonably likely to 
adversely affect polar bears or the Chukchi polar bear stock through 
effects on annual rates of recruitment or survival.
    Based on our review of these factors, we conclude that, while 
incidental harassment of polar bears and walrus is reasonably likely to 
or reasonably expected to occur as a result of proposed activities, the 
overall impact would be negligible on polar bear and Pacific walrus 
populations. In addition, we find that any takes are likely to be 
limited to Level B harassment of a relatively small number of animals 
and of relatively short-term in duration. Furthermore, we do not expect 
the anticipated level of harassment from these proposed activities to 
affect the rates of recruitment or survival of Pacific walrus and polar 
bear populations.
    We also considered the specific Congressional direction in 
balancing the potential for a significant impact with the likelihood of 
that event occurring. The specific Congressional direction that 
describes evaluating the probability of occurrence with the level of 
impact follows:

    If potential effects of a specified activity are conjectural or 
speculative, a finding of

[[Page 26779]]

negligible impact may be appropriate. A finding of negligible impact 
may also be appropriate if the probability of occurrence is low but 
the potential effects may be significant. In this case, the 
probability of occurrence of impacts must be balanced with the 
potential severity of harm to the species or stock when determining 
negligible impact. In applying this balancing test, the Service will 
thoroughly evaluate the risks involved and the potential impacts on 
marine mammal populations. Such determination will be made based on 
the best available scientific information [53 FR 8474; accord, 132 
Cong. Rec. S 16305 (Oct. 15, 1986)].

    Our finding applies to the proposed seismic programs by Shell, 
CPAI, and GXT that would occur in the Chukchi Sea region during the 
2006 open-water season. If the proposed activities are authorized, 
standard operational conditions would be attached to each 
authorization. These conditions minimize interference with normal 
breeding, feeding, and migration patterns.

Impact on Subsistence

    Based on the results of harvest data, including affected villages, 
the number of animals harvested, the season of the harvests, and the 
location of hunting areas, we find that the effects of the proposed 
seismic activities in the Chukchi Sea region would not have an 
unmitigable adverse impact on the availability of polar bears and 
Pacific walrus for taking for subsistence uses during the period of the 
activities. In making this finding, we considered the following: (1) 
Records on subsistence harvest from the Service's Marking, Tagging, and 
Reporting Program (historical data regarding the timing and location of 
harvests) and (2) anticipated effects of the applicants' proposed 
activities on subsistence hunting.
    Most subsistence walrus hunting occurs in pack-ice areas, which are 
areas typically avoided by seismic operations. Although walrus hunters 
may encounter support vessels and aircraft in open-water areas, these 
interactions are expected to be limited in area and duration and are 
not expected to affect overall hunting success. Therefore, we find that 
the proposed seismic activities will not have an unmitigable adverse 
impact on the availability of walrus for subsistence uses.
    Only a small fraction of the polar bear harvest occurs during the 
open-water season. In addition, most polar bears are harvested outside 
of the area that would be covered by this authorization. Because the 
polar bear is hunted almost entirely during the ice-covered season, it 
is unlikely that open-water seismic activities would have any effect on 
the harvest of that species. The Service anticipates that the effect of 
these seismic activities on the availability of polar bears to 
subsistence hunters would be very low if it were to occur at all. 
Therefore, we find that the proposed seismic activities would not have 
an unmitigable adverse impact on the availability of polar bears for 
subsistence uses.

Standard Operational Conditions

    The following measures will ensure that the least practicable 
impact on Pacific walrus and polar bear and on the availability of 
these species or stocks for taking for subsistence uses. These measures 
are not necessary to arrive at our conclusion that these activities 
will have a negligible impact on these species or stocks or our 
conclusion that the activities will not have unmitigable adverse impact 
on the availability of the species for subsistence purposes.
    Conditions that will be required to minimize the potential for 
harassment include the following:
    (1) Seismic and support vessels must observe a 0.5-mile (800-m) 
exclusion zone around walrus and polar bears observed on land or ice.
    (2) Aircraft will be required to maintain a 1,000-ft (300-m) 
minimum altitude within 0.5 mile (800-m) of hauled out walrus and polar 
bears.
    (3) Seismic operations will cease if walrus are sighted within a 
190 dB acoustical safety radius.
    (4) No seismic activities will take place in the Chukchi Sea before 
June 1, 2006. This prohibition would limit interference from seismic 
activities when marine mammals are concentrated in association with the 
spring lead system. This condition considers transit to and from 
activity sites as part of seismic activity, especially when support 
vessels mobilize into the Chukchi Sea for the purpose of seismic 
exploration.
    (5) Each activity would require a final walrus/polar bear 
monitoring plan that is approved by the Service. The purpose of the 
plan would be to monitor the effects of the activity on polar bears and 
walrus in the areas of seismic exploration. The monitoring plan would 
be approved by the Service prior to issuance of the incidental 
harassment authorization and will be incorporated