Taking of Marine Mammals Incidental to Specified Activities; Open Water Seismic Operations in Cook Inlet, Alaska, 536-541 [E6-22634]

Agencies

• DEPARTMENT OF COMMERCE
• National Oceanic and Atmospheric Administration

[Federal Register Volume 72, Number 3 (Friday, January 5, 2007)]
[Notices]
[Pages 536-541]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: E6-22634]



[[Page 536]]

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DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 110906A]


Taking of Marine Mammals Incidental to Specified Activities; Open 
Water Seismic Operations in Cook Inlet, Alaska

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

ACTION: Notice; proposed authorizations for two incidental take 
authorizations; request for comments.

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SUMMARY: NMFS has received requests from ConocoPhillips Alaska, Inc. 
(CPAI) and from Union Oil Company of California (UOCC) for 
authorizations to take small numbers of five marine mammal species 
incidental to seismic operations in portions of Cook Inlet, Alaska. 
Under the Marine Mammal Protection Act (MMPA), NMFS is requesting 
comments on its proposal to issue authorizations to CPAI and UOCC to 
incidentally take, by harassment, small numbers of these species 
between approximately mid-March and mid-June, 2007.

DATES: Comments and information must be received no later than February 
5, 2007.

ADDRESSES: Comments on the applications and draft Environmental 
Assessment (EA) 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, or by telephoning the contact listed 
here. The mailboxes address for providing e-mail comments are 
PR1.110906A@noaa.gov. Comments sent via e-mail, including all 
attachments, must not exceed a 10-megabyte file size. Copies of the 
applications, the application letters, draft EA, and other related 
documents may be obtained by writing to this address or by telephoning 
one of the contacts listed here (see FOR FURTHER INFORMATION CONTACT). 
The applications and draft EA are also available at: https://
www.nmfs.noaa.gov/pr/permits/incidental.htm.

FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected 
Resources, NMFS, (301) 713-2289, ext 137, or Brad Smith, Alaska Region, 
NMFS, (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 small numbers of marine 
mammals by U.S. citizens who engage in a specified activity (other than 
commercial fishing) within a specified geographical region if certain 
findings are made and either regulations are issued or, if the taking 
is limited to harassment, 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 that the permissible methods of 
taking and requirements pertaining to the mitigation, monitoring and 
reporting of such taking are set forth. NMFS has defined ``negligible 
impact'' in 50 CFR 216.103 as ''...an impact resulting from the 
specified activity that cannot be reasonably expected to, and is not 
reasonably likely to, adversely affect the species or stock through 
effects on annual rates of recruitment or survival.''
    Section 101(a)(5)(D) of the MMPA established an expedited process 
by which citizens of the United States can apply for an authorization 
to incidentally take small numbers of marine mammals by harassment. 
Except with respect to certain activities not pertinent here, the MMPA 
defines ``harassment'' as:
    any act of pursuit, torment, or annoyance which (i) has the 
potential to injure a marine mammal or marine mammal stock in the 
wild [Level A harassment]; or (ii) has the potential to disturb a 
marine mammal or marine mammal stock in the wild by causing 
disruption of behavioral patterns, including, but not limited to, 
migration, breathing, nursing, breeding, feeding, or sheltering 
[Level B harassment].
    Section 101(a)(5)(D) establishes a 45-day time limit for NMFS 
review of an application followed by a 30-day public notice and comment 
period on any proposed authorizations for the incidental harassment of 
small numbers of marine mammals. Within 45 days of the close of the 
comment period, NMFS must either issue or deny issuance of the 
authorization.

Summary of Request

    On October 6 and on October 12, 2006, NMFS received applications 
from CPAI and UOCC, respectively, requesting Incidental Harassment 
Authorizations (IHAs) for the possible harassment of small numbers of 
the Cook Inlet beluga whale (Delphinapterus leucas), Steller lions 
(Eumetopias jubatus), Pacific harbor seals (Phoca vitulina richardsi), 
harbor porpoises (Phocoena phocoena), and killer whales (Orcinus orca) 
incidental to conducting open water seismic operations in portions of 
Cook Inlet, Alaska.
    Both proposed operations use an ocean-bottom cable (OBC) system to 
conduct seismic surveys. OBC seismic surveys are used in waters that 
are too shallow for the data to be acquired using a marine-streamer 
vessel and/or too deep to have static ice in the winter. This type of 
seismic survey requires the use of multiple vessels for cable layout/
pickup, recording, shooting, and possibly one or two vessels smaller 
than those used in streamer operations. The utility boats can be very 
small, in the range of 10 - 15 m (33 - 49 ft).
    An OBC operation begins by laying cables off the back of the layout 
vessel. Cable length typically is 4 - 6 km (2.5 - 3.7 miles) but can be 
up to 12 km (7.4 miles). Groups of seismic survey receivers (usually a 
combination of both hydrophones and vertical-motion geophones) are 
attached to the cable in intervals of 25 - 70 m (82 - 246 ft). Multiple 
cables are laid on the seafloor parallel to each other using this 
layout method, with a cable spacing of less than 0.5 mile (0.8 km), 
depending on the geophysical objective of the survey. The sound source 
levels (zero to peak) associated with the OBC seismic survey are the 
same for most 2D and 3D marine seismic surveys (233 - 240 dB re 1 
microPa at 1 m).
    The proposed operations would be active 24 hours per day, but the 
airguns would only be active for 1 - 2 hours during each of the 3 - 4 
daily slack tide periods. The source for the proposed OBC seismic 
surveys would be a 900-in\3\ BOLT airgun array situated on the source 
vessel, the Peregrine Falcon. The array would be made up of 2 sub-
arrays, each with 2 3-airgun clusters separated by 1.5 m (4.9 ft) off 
the stern of the vessel. One cluster will consist of 3 225-in\3\ 
airguns and the second cluster will have 3 75-in\3\ airguns. During 
seismic operations, the sub-arrays will fire at a rate of every 10 - 25 
seconds and focus energy in the downward direction as the vessel 
travels at 4 - 5 knots (4.6 - 5.8 mph). Source level of the airgun 
array is 249 dB re 1 microPa at 1 m (0 - peak), and the dominant 
frequency range is 8 - 40 Hz.
    A near-field hydrophone is mounted about 1 m (3.3 ft) above each 
airgun station (one hydrophone is used per cluster), one depth 
transducer per

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position is mounted on the airgun's ultrabox, and a high pressure 
transducer is mounted at the aft end of the sub-array to monitor high 
pressure air supply. A single 200 CFM PRICE compressor would supply air 
for the array. The compressor would be run through a pressure regulated 
valve tree. Water separators and dehumidifiers are also part of the 
source system. The array would be located with the use of DGPS antennas 
located on top of the A-frames. The A-frame would be lowered and raised 
based on water depth before the firing of the airguns.
    The geographic region for the seismic operation proposed by CPAI 
encompasses a 25 km\2\ (9.7 square miles) area in northwestern Cook 
Inlet, paralleling the shoreline from just offshore of the Beluga River 
south for about 6 km (3.7 miles). The approximate boundaries of the 
region of the proposed project area are 61[deg]09.473' N, 
151[deg]11.987' W; 61[deg]16.638' N, 151[deg]02.198' W; 61[deg]12.538' 
N, 150[deg]49.979' W; and 61[deg]05.443' N, 1517[deg]00.165' W. Water 
depths range from 0 to 24 m (80 ft). There will be a 1.6 km (1 mile) 
setback of operations from the mouth of the Beluga River to comply with 
Alaska Department of Fish and Game (ADFG) restrictions. The proposed 
seismic operations would occur from mid March depending on the time of 
ice breakup, and last until mid-May, 2007.
    The geographic region for the activity proposed by UOCC encompasses 
a 28.2 km\2\ (10.9 square miles) area in northwestern Cook Inlet, 
paralleling the shoreline offshore of Granite Point, and extending from 
shore into the inlet to an average of about 1.6 km (1 mile). The 
approximate boundaries of the region of the proposed project area are 
61[deg]00.827' N, 151[deg]24.071' W; 61[deg]02.420' N, 151[deg]15.375' 
W; 61[deg]00.862' N, 150[deg]15.313' W; and 61[deg]57.979' N, 
151[deg]23.946' W. There are no major rivers flowing into the open 
water seismic project area. Water depths range from 0 to 18 m (60 ft). 
The proposed seismic operations would begin as early as May 1 and end 
no later than June 15, 2007.

Description of the Marine Mammals Potentially Affected by the Activity

    The marine mammals that are potentially found in Cook Inlet are the 
Cook Inlet beluga whales, Steller sea lions, Pacific harbor seals, 
harbor porpoises, and killer whales. Among these species, only the 
Steller sea lion is listed as endangered under the Endangered Species 
Act (ESA), and it is also designated as depleted under the MMPA. The 
Cook Inlet beluga whale is designated as depleted under the MMPA. 
General information for these species can be found in Angliss and 
Outlaw (2006), which is available at the following URL: https://
www.nmfs.noaa.gov/pr/pdfs/sars/ak2005.pdf. Additional information on 
these species is presented below.

Cook Inlet beluga whale

    In the U.S. waters, beluga whales comprise five distinct stocks: 
Beaufort Sea, Eastern Chukchi Sea, Eastern Bering Sea, Bristol Bay, and 
Cook Inlet (Angliss and Outlaw, 2005). For the proposed seismic 
operations, only the Cook Inlet beluga stock occurs in the project 
area. The Cook Inlet stock is the most isolated of the five stocks, 
based on the degree of genetic differentiation between this stock and 
the four others (O'Corry-Crowe et al., 1997).
    The Cook Inlet beluga whale population has declined significantly 
over the years (NMFS, 2005). NMFS systematic aerial surveys documented 
a decline in abundance of nearly 50 percent between 1994 and 1998, from 
an estimate of 653 whales to 347 whales (Hobbs et al., 2000). The 
annual abundance surveys conducted each June from 1999 to 2005 have 
resulted in abundance estimates of 367, 435, 386, 313, 357, 366, and 
278 whales for each year, respectively (Rugh et al., 2006). The Cook 
Inlet beluga whale stock is considered below its Optimum Sustainable 
Population. There is considerable concern regarding its small 
population size.
    Cook Inlet beluga whales demonstrate site fidelity to summer 
concentration areas, where they regularly occur in just a few areas 
each year (Seaman et al., 1985), typically near river mouths and 
associated shallow, warm and low salinity waters (Moore et al/, 2000). 
While there is inter-annual variability in beluga use among areas, 
generally belugas occur in the Susitna and Chickaloon areas in May to 
July, Turnagain Arm in August, Knik Arm in September, and the mid-Cook 
Inlet between Point Possession and Kalgin Island in January through 
April (Hansen and Hubbard, 1999; Rugh et al., 2000; 2004; 2005). These 
patterns are consistent with those recorded for 14 tagged beluga whales 
tracked by satellite from 2000 to 2003 (Hobbs et al., 2005).
    Within this distribution, NMFS has characterized the relative value 
of 4 habitats as part of the management and recovery strategy in its 
Draft Conservation Plan for the Cook Inlet Beluga Whale (Delphinapterus 
leucas) (NMFS, 2005). Type 1 habitat is termed ``High Value/High 
Sensitivity'' and includes what NMFS believes to be the most important 
and sensitive areas of the Inlet in terms of beluga whales. Type 2 is 
termed ``High Value,'' and include summer feeding areas and winter 
habitats in waters where whales typically occur in lesser densities or 
in deeper waters. Type 3 habitat occurs in the offshore areas of the 
mid and upper Inlet and also includes wintering habitat. Type 4 habitat 
describes the remaining portions of the range of these whales within 
Cook Inlet.
    Beluga whale use and distribution within Cook Inlet is documented 
from a study using satellite tracking of tagged whales (Hobbs et al., 
2005). Among the 14 beluga whales monitored by satellite telemetry 
between July and March in 2000 - 2003, all remained in Cook Inlet the 
entire time they were tracked. During summer and fall, whales were 
concentrated in rivers and bays in Upper Cook Inlet; during winter, 
they were more dispersed and located farther offshore. From December 
through March, whales were located primarily offshore and ranged widely 
in upper and mid Cook Inlet. Based on this study, it can be inferred 
that at least some belugas can be found in the CPAI and UOCC proposed 
project vicinities most months of the year as they seasonally move 
between the upper and lower Inlet, and between inshore and offshore 
waters. It can also be inferred that beluga whale occurrence in or near 
the UOCC Granite Point project area during late spring and early summer 
is much infrequent as most belugas will be concentrated in rivers and 
bays farther north in the Upper Inlet (Rugh et al., 2000; Hobbs et al., 
2005; Rugh et al/, 2005). Beluga River area is in the extreme southern 
edge of the area classified by NMFS as Type 2 habitat, which is a 
summer feeding site. The Granite Point project area is within Type 3 
habitat, which is a wintering area and secondary summering site, and 
historic sites.
    Sources of Cook Inlet beluga whale mortality include strandings 
(Vos and Shelden, 2005), predation by killer whales (Shelden et al., 
2003), and subsistence harvest (Mahoney and Shelden, 2000; NMFS, 2003; 
2005).

Steller sea lion

    The western U.S. stock of Steller sea lion is distributed 
throughout the Bering Sea, the North Pacific Ocean, and the Gulf of 
Alaska east to 144oW, which includes Cook Inlet (Loughlin, 1997). The 
most recent minimum estimate of this population was 38,513 animals, 
including pups (Angliss and Outlaw, 2005). No abundance estimate for 
Steller sea lions is available for Cook Inlet.

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    Steller sea lions are sighted in Lower Cook Inlet than in the upper 
Inlet (LGL, 2006). Steller sea lion critical habitat has been 
established at locations in the southern portion of Lower Cook Inlet 
(58 FR 45269, August 27, 1993). Haulouts in the lower Inlet are located 
near the mouth of Cook Inlet at Gore Point, Elizabeth Island, Perl 
Island, the Barren Islands, and Chugach Island. Steller sea lions 
gather on traditional rookeries from mid-May through mid-July to give 
birth and breed. No haulouts occur in Upper Cook Inlet, the geographic 
region in which the proposed seismic activities would occur, and 
animals are rarely sighted north of Nikiski (Rugh et al., 2005; LGL, 
2006).

Pacific harbor seal

    Harbor seals are present in coastal waters throughout Cook Inlet. 
They are more abundant in lower Cook Inlet than in the upper Inlet 
(Rugh et al/, 2005). In the Upper Inlet, harbor seals occur in the 
Little Susitna River, Susitna River, Turnagain Arm, Chickaloon Bay, 
Knik Arm, and Beluga River from May through October (Rugh et al., 
2005). Typically, fewer than about 100 harbor seals have been recorded 
in any one of these locations with the majority in the Chickaloon Bay 
and the Susitna River areas and very few at the Beluga River (Rugh et 
al., 2005). One to three harbor seals have been annually reported in or 
near the Beluga River area (Rugh et al., 2005).
    Major harbor seal haulout sites in the Cook Inlet region are found 
in the lower portion of the Inlet. The reproductive period (pupping and 
breeding) occurs at most major haulouts in the Inlet from May through 
July (NMFS, 2003). Harbor seals molt following the reproductive period. 
The peak season for molting in the Gulf of Alaska occurs from July to 
September (Pitcher and Calkins, 1979).
    The population size of the Gulf of Alaska stock is estimated at 
29,175 seals (Angliss and Outlaw, 2005). However, no abundance estimate 
is available for Cook Inlet. Harbor seals have declined in some areas 
of the northern Gulf of Alaska by 78 percent during the past two 
decades (Fadely et al., 1997). Causes of this decline may include 
natural population fluctuations or cycles, reduced environmental 
carrying capacity and prey availability due to natural or human causes, 
predation, harvests, direct fisheries related mortality, entanglement 
in marine debris, pollution, and emigration (Hoover-Miller, 1994).

Harbor porpoise

    Harbor porpoise occur throughout Alaska waters (Lowry et al/, 
1982). The Gulf of Alaska stock of harbor porpoise, which includes Cook 
Inlet animals, is estimated at 30,506 animals (Angliss and Outlaw, 
2005). Dahlheim et al. (2000) estimated the average density of harbor 
porpoises in Cook Inlet was 7.2 animals per 1,000 km2 (386 square 
miles), or 1 animal per 139 km2 (53 square miles), which indicates 
densities are very low in the Inlet. Harbor porpoises occur in Upper 
Cook Inlet throughout the year in small numbers but are more abundant 
in the lower Inlet (LGL, 2006).

Killer whale

    The Eastern North Pacific stocks of killer whales includes 
transient and resident killer whales in the Gulf of Alaska and Cook 
Inlet (Angliss and Outlaw, 2005). The minimum abundance estimated for 
the Alaska Resident stock of killer is 1,123 animals; and for the Gulf 
of Alaska, Aleutian Islands, and Bering Sea Transient stock of killer 
whale is 314 animals (Angliss and Outlaw, 2005).
    Killer whales in Cook Inlet have not been well documented (Shelden 
et al., 2003). However, their occurrence in the area is sporadic and 
not considered a daily or common event. Resident and transient killer 
whales have been observed. Most sightings of resident killer whales 
occur in the lower Inlet (Shelden et al., 2003). Small groups of killer 
whales, believed to be transient whales, have been seen in upper Cook 
Inlet (NMFS, 2003). Rugh et al/ (2005) reported observing no killer 
whales in the upper Inlet and only 23 in the lower Inlet during surveys 
from 1993 to 2004. Similarly, two recent marine mammal studies in the 
upper Inlet and Knik Arm did not observe any killer whales (Funk et 
al., 2005; Ireland et al., 2005). There are no records of killer whales 
in the Beluga River and Granite Point project areas.
    Potential Effects on Marine Mammals and Their Habitat
    Seismic surveys using acoustic energy may have the potential to 
adversely impact marine mammals in the vicinity of the activities 
(Gordon et al., 2004). The sound source levels (zero to peak) 
associated with the OBC seismic survey can be as high as 233 - 240 dB 
re 1 microPa at 1 m. However, most energy is directed downward, and the 
short duration of each pulse limits the total energy. Received levels 
within several kilometers typically exceed 160 dB re 1 microPa 
(Richardson et al/, 1995), depending on water depth, bottom type, ice 
cover, etc. Intense acoustic signals from seismic surveys have been 
known to cause behavioral alteration such as reduced vocalization rates 
(Goold, 1996), avoidance (Malme et al., 1986, 1988; Richardson et al., 
1995; Harris et al., 2001), and changes in blow rates (Richardson et 
al., 1995) in several marine mammal species.
    The proposed surveys would use a 900-in\3\ BOLT airgun array 
consisting of 3 225-in\3\ airguns and 3 75-in\3\ airguns. The source 
level of this array is expected to be considerably lower than the 
1,200-in\3\ BOLT airgun array used by the U.S. Coast Guard (USCG) 
vessel Healy (70 FR 47792, August 15, 2005). To conservatively assess 
the received levels from airgun pulses, the USCG's Healy modeled data 
were used to calculate the maximum distances where sound levels would 
be 190, 180, and 160 dB re 1 microPa rms. The maximum distances where 
sound levels were estimated at 190, 180, and 160 dB re 1 microPa rms 
from a single 1,200-in\3\ BOLT airgun in the northern Beaufort Sea were 
313 m (1,027 ft), 370 m (1,214 ft), and 1,527 m (5,010 ft), 
respectively. However, since the proposed seismic surveys would use a 
smaller 900-in\3\ airgun array in an area with soft mud bottom that 
gradually slopes outward from shore, which is a poor condition for 
sound transmission (Richardson et al., 1995), the received levels are 
expected to be significantly lower at these distances.
    The seismic surveys would only introduce acoustic energy into the 
water column and no objects would be released into the environment. The 
survey vessels would travel at a speed of 4 5 knots and the two 
projects would be conducted in a small area of Cook Inlet for a short 
period.
    There is a relative lack of knowledge about the potential impacts 
of seismic energy on marine fish and invertebrates. Available data 
suggest that there may be physical impacts on eggs and on larval, 
juvenile, and adult stages of fish at very close range (within meters) 
to seismic energy source. Considering typical source levels associated 
with seismic arrays, close proximity to the source would result in 
exposure to very high energy levels. Where eggs and larval stages are 
not able to escape such exposures, juvenile and adult fish most likely 
would avoid them. In the cases of eggs and larvae, it is likely that 
the numbers adversely affected by such exposure would be very small in 
relation to natural mortality. Studies on fish confined in cages that 
were exposed under intense sound for extended period showed physical or 
physiological impacts (Scholik and Yan, 2001; 2002;

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McCauley et al., 2003; Smith et al., 2004). While limited data on 
seismic surveys regarding physiological effects on fish indicate that 
impacts are short-term and are most apparent after exposure at very 
close range (McCauley et al., 2000a; 2000b; Dalen et al., 1996), other 
studies have demonstrated that seismic guns had little effect on the 
day-to-day behavior of marine fish and invertebrates (Knudsen et al., 
1992; Wardle et al., 2001). It is more likely that fish will swim away 
upon hearing the approaching seismic impulses (Engas et al., 1996). 
Based on the foregoing, NMFS finds preliminarily that the proposed 
seismic surveys would not cause any permanent impact on the physical 
habitats and marine mammal prey species in the proposed project area.

Number of Marine Mammals Expected to Be Taken

    NMFS estimates that approximately 6 - 57 Cook Inlet beluga whales 
(average 26 whales) out of a population of 278 whales and a maximum of 
30 Pacific harbor seals out of a population of 29,175 seals would be 
harassed incidentally by the two proposed seismic operations from March 
to June, 2007. These numbers of take represent 2.2 - 20.5 percent 
(average 9.4 percent) Cook Inlet beluga whales and less than 0.1 
percent of Alaska stock of Pacific harbor seals that could be taken by 
Level B harassment if no mitigation and monitoring measures are 
implemented. These numbers are based on the animal density, length of 
track planned, and the assumption that all animals will be harassed at 
distances where noise at received level is at and above 160 dB re 1 
microPa rms. Beluga whale and harbor seal densities were calculated by 
dividing the daily counts of whales (ranges from 11 - 99, with an 
average of 46) and seals (75) by the approximate area (1,248 km\2\, or 
482 square miles) surveyed in the Susitna Delta (Beluga River to Pt. 
MacKenzie) during the most recently published survey for June 2004 
(Rugh et al/, 2005). Although 20.5 percent of Cook Inlet beluga whales 
could subject to take by Level B harassment, this estimate was based on 
an unusually high count of whales on June 3, 2004 in Susitna Delta 
(from North Foreland to Pt. Mackenzie). Cook Inlet beluga aerial 
surveys conducted by NMFS in June, 2003 and 2004, provided median 
counts of whales between 0 - 99, with an average count of 29 whales in 
the same area. This estimate is conservative as it assumes that all 
animals exposed by seismic impulses over 160 dB re 1 microPa would be 
harassed and disturbed. As mentioned earlier that the majority acoustic 
energy of low frequency airgun impulses falls outside beluga whale's 
most sensitive hearing range (Richardson et al., 1995), it is most 
likely that only a portion of whales within the 160 dB re 1 microPa 
isopleth would be disturbed. In addition, it is also possible that many 
of the animals would be habituated to this level of acoustic 
disturbances. Furthermore, mitigation measures, including the ramp-up 
requirement during the initiation of the seismic operations (see below) 
could eliminate most, if not all, startling behavior from animals near 
the proposed project area. Therefore, NMFS believes that the actual 
number of Level B harassment takes of Cook Inlet beluga whale would be 
much lower than the estimated average of 26 whales.
    There are no similar population surveys for harbor porpoises, 
Steller sea lions, and killer whales conducted within the proposed 
project area. However, based on an abundance survey of harbor porpoises 
within the entire Cook Inlet (Dahlheim et al., 2000), it is estimated 
that the population density of harbor porpoise in the entire Inlet is 
0.0072 animal per km2. Based on this density data, NMFS estimates that 
about 6 harbor porpoises out of a population of 30,506 porpoises could 
be harassed incidentally by the two proposed seismic operations from 
March to June, 2007. This number of take represents less than 0.02 
percent of harbor porpoises that could be taken by Level B harassment.
    There is no density estimates available for Steller sea lions and 
killer whales with in Cook Inlet. However, their appearance in Upper 
Cook Inlet is rare and none of these species were sighted in the upper 
Inlet during the 2004 survey (Rugh et al., 2005). Therefore, NMFS 
concludes that the harassment of these species is reasonably believed 
to be much lower than those of beluga whales and harbor seals.

Effects on Subsistence Needs

    The proposed project areas are located 4 - 15 miles (6.4 - 24.1 km) 
from Tyonek, which is predominately a Dena'ina Athabaskan community. 
However, these areas are not important subsistence areas for Tyonek 
hunters. The Tyonek native community has been displaced from many 
traditional hunting (and trapping and fishing) areas north of Tyonek 
including Beluga River during the twentieth century. As more non-
natives utilized and occupied traditional subsistence areas combined 
with harvest regulation restrictions, changes in the abundance and 
distribution of subsistence resources, and other factors, Tyonek native 
subsistence activities have focused closer to the village. While Tyonek 
natives may harvest one beluga whale per year and occasionally harbor 
seals (Huntington, 2000), their primary source of meat is moose 
(Foster, 1982). Therefore, NMFS believes that the proposed projects 
would not have an unmitigable adverse impact on the availability of 
marine mammal species or stocks for subsistence harvest.

Mitigation

    The following mitigation measures are proposed be required under 
the proposed IHA to be issued to CPAI and UOCC for conducting seismic 
operations in northwestern Cook Inlet. NMFS believes that the 
implementation of these mitigation measures would result in the least 
practicable impact on marine mammal species or stocks and their 
habitat.

Time and Frequency

    Seismic operations would be limited from mid-March to mid-June in 
portions of northwestern Cook Inlet. During the seismic operations, 
airguns would only be active for 1 - 2 hours during each of the 3 - 4 
slack tide periods, with the vessel moving at a speed of 4 - 5 knots 
(4.6 - 5.8 mph).
    There will be a 1.6 km (1 mile) set back of airguns from the mouth 
of the Beluga River to comply with ADFG restrictions.

Establishment of Safety Zones

    The applicants propose to establish a 370-m (1,214-ft) radius 
safety zone for cetaceans and a 313-m (1,027-ft) radius safety zone for 
pinnipeds for the seismic operations. These safety zone radii were 
calculated from a model for a 1,200-in3 BOLT array used in the Beaufort 
Sea where the received sound pressure levels (SPL) attenuated to 180 dB 
and 190 dB re 1 microPa rms, respectively. Since the data used in 
calculating the size of safety zones were from a much larger array, 
while the proposed seismic operations would use a smaller array in an 
area with poor conditions for sound transmission, NMFS believes that 
these safety zone radii are conservative. Additional data will be 
acquired to verify the 190, 180, and 160 dB (rms) distances for the 
airgun configurations during the proposed seismic operations, and the 
disturbance could be modified if NMFS finds that the level of take is 
being exceeded and resulting in higher than a negligible impact on the 
species or stock in question. An independent marine acoustic firm, will 
be used to acquire the data. Scientifically valid

[[Page 540]]

sampling design will be followed to collect data at the beginning of 
the seismic program. The data will be used to calibrate the acoustic 
model and adjust the safety radii to match the field values for the 
190, 180, and 160 dB distances for each array, if different from these 
estimated values.
    Safety zones would be surveyed and monitored prior to, during, and 
after the airgun seismic operations. A detailed description of marine 
mammal monitoring is described in the Monitoring and Reporting section 
below.

Speed and Course Alteration

    If a marine mammal is detected outside the safety radius and based 
on its position and the relative course of travel is likely to enter 
the safety zone, the vessel's speed and/or direct course may, when 
practicable and safe, be changed to avoid the impacts to the animal. 
The marine mammal activities and movements relative to the seismic and 
support vessels must be closely monitored to ensure that the animal 
does not (1) approach the safety radius, or (2) enter the safety zone. 
If either of these scenarios occur, further mitigation measures must be 
taken (i.e., either further course alterations or power down or shut 
down of the airgun(s)).

Power-down Procedures

    A power down involves decreasing the number of airguns in use such 
that the radius of the 180- or 190-dB zone is decreased to the extent 
that marine mammals are not in the safety zone. During a power-down, 
one airgun is operated. The continued operation of one airgun is 
intended to alert marine mammals to the presence of the seismic guns in 
the area.
    If a marine mammal is detected outside the safety zone but is 
likely to enter the safety zone, and if the vessel's course and/or 
speed cannot be changed to avoid having the animal enter the safety 
radius, the airguns must be powered down before the animal is within 
the safety zone.

Shut-down Procedures

    A shut-down occurs when all airgun activity is suspended. The 
operating airgun(s) must be shut down if a marine mammal approaches the 
applicable safety zone and a power down still would not likely to keep 
the animal outside the newly adjusted smaller safety zone. The 
operating airgun(s) must also be shut down completely if a marine 
mammal is found within the safety zone during the seismic operations. 
The shut-down procedure should be accomplished within several seconds 
(of a ``one shot'' period) of the determination that a marine mammal is 
within or about to enter the safety zone.
    Following a shut-down, airgun activity will not resume until the 
marine mammal has cleared the safety zone. The animal will be 
considered to have cleared the safety zone if it is visually observed 
to have left the safety zone, or if it has not been seen within the 
safety zone for 15 minutes.

Ramp-up Procedures

    Although marine mammals will be protected from Level A harassment 
by establishment of a safety zone at a SPL levels of 180 and 190 dB re 
1 microPa rms for cetaceans and pinnipeds, respectively, mitigation may 
not be 100 percent effective at all times in locating marine mammals. 
In order to provide additional protection to marine mammals near the 
project area by allowing marine mammals to vacate the area prior to 
receiving a potential injury, and to further reduce Level B harassment 
by startling marine mammals with a sudden intensive sound, CPAI and 
UOCC will be required to implement ``ramp-up'' practice when starting 
up airgun arrays. Ramp-up will begin with the smallest airgun in the 
array that is being used for all subsets of the 6-gun array. Airguns 
will be added in a sequence such that the source level in the array 
will increase at a rate no greater than 6 dB per 5 minutes. During the 
ramp-up, the safety zone for the full 6-airgun system will be 
maintained.

Monitoring and Reporting

    Monitoring would be conducted by qualified NMFS-approved marine 
mammal observers (MMOs). Reticle binoculars (e.g., 7 x 50 Bushnell or 
equivalent) and laser range finders (Leica LRF 1200 laser range finder 
or equivalent) would be standard equipment for the monitors.
    Vessel-based MMOs will begin marine mammals monitoring at least 30 
minutes prior to the planned start of airgun operations and during all 
periods of airgun operations. MMOs will survey the safety zone to 
ensure that no marine mammals are seen within the zone before a seismic 
survey begins. If marine mammals are found within the safety zone, 
seismic operations will be suspended until the marine mammal leaves the 
area. If a marine mammal is seen above the water and then dives below, 
the operator will wait 15 minutes, and if no marine mammals are seen by 
the MMOs in that time it will be assumed that the animal has moved 
beyond the safety zone. When feasible, observations will also be made 
during transits, moving cable, and other operations when airguns are 
inactive.
    Data for each distinct marine mammal species observed in the 
proposed project area during the period of the seismic operations would 
be collected. Numbers of marine mammals observed, species 
identification if possible, frequency of observation, the time 
corresponding to the daily tidal cycle, and any behavioral changes due 
to the airgun operations will be recorded and entered into a custom 
database using a notebook computer. The accuracy of the data entry will 
be verified by computerized validity data checks as the data are 
entered and by subsequent manual checking of the database. These 
procedures will allow initial summaries of data to be prepared during 
and shortly after the field program, and will facilitate transfer of 
the data to statistical, graphical, or other programs for further 
processing and archiving.
    Results from the vessel-based observations will provide: (1) Basis 
for real-time mitigation (airgun shut-down); (2) information needed to 
estimate the number of marine mammals potentially taken by harassment, 
which must be reported to NMFS; (3) data on the occurrence, 
distribution, and activities of marine mammals in the area where the 
seismic study is conducted; (4) information to compare the distance and 
distribution of marine mammals relative to the source vessel at times 
with and without seismic activity; and (5) data on the behavior and 
movement patterns of marine mammals seen at times with and without 
seismic activity.
    Reports from CPAI and UOCC will be submitted to NMFS within 90 days 
after the end of the respective projects. The reports will describe the 
operations that were conducted, the marine mammals that were detected 
near the operations, and provide full documentation of methods, 
results, and interpretation pertaining to all monitoring. The reports 
will also include estimates of the amount and nature of potential 
``take'' of marine mammals by harassment or in other ways.

National Environmental Policy Act (NEPA)

    NMFS has prepared a draft EA for public review and comment (see 
ADDRESSES), that describes the impact on the human environment that 
would result from implementation of this action. NMFS has concluded, 
preliminarily, that no significant impact on the human environment 
would result.

[[Page 541]]

Endangered Species Act (ESA)

    Based on a review conducted by NMFS Alaska Regional Office 
biologists, it is not likely that any ESA-listed species would be taken 
due to the proposed seismic operations. Steller sea lions are recorded 
in these waters, but are considered uncommon in spring and early summer 
in the proposed project area. Therefore, NMFS has determined that a 
formal section 7 consultation is not necessary.

Preliminary Determinations

    NMFS has determined preliminarily that small numbers of beluga 
whales, Pacific harbor seals, and harbor porpoises may be taken 
incidental to seismic surveys, by no more than Level B harassment and 
that such taking will result in no more than a negligible impact on 
such species or stocks. In addition, NMFS has determined preliminarily 
that Steller sea lions and killer whales, if present within the 
vicinity of the proposed activities could be taken incidentally, buy by 
no more than Level B harassment and that such taking would result in no 
more than a negligible impact on such species or stocks. At this time, 
NMFS is not able to determine whether any potential take would involve 
small numbers of Steller sea lions or killer whales due to data 
limitations and our inability to develop density estimates. Regardless, 
given the infrequent occurrence of these species (or none at all), NMFS 
believes that any take would be significantly lower than those of 
beluga whales or harbor seals.
    While behavioral modifications, including temporarily vacating the 
area during the project period may be made by these species to avoid 
the resultant visual and acoustic disturbance, NMFS nonetheless finds 
that this action would result in no more than a negligible impact on 
these marine mammal species and/or stocks. NMFS also finds that the 
proposed action will not have an unmitigable adverse impact on the 
availability of such species or stocks for taking for subsistence uses.
    In addition, no take by Level A harassment (injury) or death is 
anticipated or authorized, and harassment takes should be at the lowest 
level practicable due to incorporation of the mitigation measures 
described in this document.

Proposed Authorization

    NMFS proposes to issue IHAs to CPAI and UOCC for the potential 
harassment of small numbers of Cook Inlet beluga whales, Pacific harbor 
seals and harbor porpoises incidental to conducting seismic operations 
in the northwestern Cook Inlet in Alaska, provided the previously 
mentioned mitigation, monitoring, and reporting requirements are 
incorporated. Likewise, NMFS proposes to issue IHAs for potential 
harassment of Steller sea lions and killer whales incidental to 
conducting of seismic operations in the northwestern Cook Inlet in 
Alaska, provided that previously mentioned mitigation, monitoring, and 
reporting requirements are incorporated.

    Dated: December 28, 2006.
James H. Lecky,
Director, Office of Protected Resources, National Marine Fisheries 
Service.
[FR Doc. E6-22634 Filed 1-4-07; 8:45 am]
BILLING CODE 3510-22-S