Incidental Takes of Marine Mammals During Specified Activities: Shallow Hazard and Site Clearance Surveys in the Chukchi Sea (2008)

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Federal Register: May 23, 2008 (Volume 73, Number 101)

Notices

Page 30064-30073

From the Federal Register Online via GPO Access [wais.access.gpo.gov]

DOCID:fr23my08-43

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

RIN 0648-XH65

Incidental Takes of Marine Mammals During Specified Activities;

Shallow Hazard and Site Clearance Surveys in the Chukchi Sea in 2008

AGENCY: National Marine Fisheries Service (NMFS), National Oceanic and

Atmospheric Administration (NOAA), Commerce.

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

SUMMARY: NMFS has received an application from ConocoPhillips Alaska,

Inc. (CPAI) for an Incidental Harassment Authorization (IHA) to take small numbers of marine mammals, by harassment, incidental to conducting shallow hazard and site clearance surveys using acoustic equipment and small airguns in the Chukchi Sea between August and

October 2008. Under the Marine Mammal Protection Act (MMPA), NMFS is requesting comments on its proposed IHA for these activities.

DATES: Comments and information must be received no later than June 23, 2008.

ADDRESSES: Comments on the application should be addressed to P.

Michael Payne, Chief, Permits, Conservation and Education Division,

Office of Protected Resources, National Marine Fisheries Service, 1315

East-West Highway, Silver Spring, MD 20910-3225. The mailbox address for providing email comments is PR1.0648-XH65@noaa.gov. NMFS is not responsible for e-mail comments sent to addresses other than the one provided here. Comments sent via e-mail, including all attachments, must not exceed a 10-megabyte file size.

A copy of the application containing a list of the references used in this document may be obtained by writing to the address specified above, telephoning the contact listed below (see FOR FURTHER

INFORMATION CONTACT), or visiting the internet at: http:// www.nmfs.noaa.gov/pr/permits/incidental.htm.

Documents cited in this notice may be viewed, by appointment, during regular business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Shane Guan, Office of Protected

Resources, NMFS, (301) 713-2289, ext 137.

SUPPLEMENTARY INFORMATION:

Background

Sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361 et seq.) direct the Secretary of Commerce to allow, upon request, the incidental, but not intentional, taking of marine mammals by U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if certain findings are made and either regulations are issued or, if the taking is limited to harassment, a notice of a proposed authorization is provided to the public for review.

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 certain subsistence uses, and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring and reporting of such takings are set forth. NMFS has defined ``negligible impact'' in 50 CFR 216.103 as ''...an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival.''

Section 101(a)(5)(D) of the MMPA established an expedited process by which citizens of the United States can apply for an authorization to incidentally take small numbers of marine mammals by harassment.

Except with respect to certain activities not pertinent here, the MMPA defines ``harassment'' as: any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild [Level A harassment]; or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering

Level B harassment

.

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

Summary of Request

On April 30, 2008, NMFS received an application from CPAI for the taking, by Level B harassment, of several species of marine mammals incidental to conducting shallow hazard and site clearance surveys using acoustic equipment and small airguns in the Chukchi Sea for up to 30 - 45 days from approximately August 1, 2008 until October 31, 2008.

The geographic region of the proposed activities includes two areas spaced about 60 km (37 mi) apart and a path for sampling conditions along a potential pipeline route. Each area is about 2,000 km2 (772.5 mi2) with dimensions about 72 km (45 mi) by 62 km (38.5 mi). The two areas are about 111 km (69 mi) off the Alaska coast, generally west from the village of Wainwright. The marine surveys will be performed from a seismic vessel.

Description of the Specified Activity

CPAI is planning to conduct site clearance and shallow hazard surveys of potential exploratory drilling sites in the Chukchi Sea during the 2008 open water season. Site clearance and shallow hazard surveys would begin in August, after completing mobilization in July.

CPAI anticipates shooting approximately 5,300 linear km (3,294 mi). The operation will be active 24 hours per day and use a single vessel to collect the geophysical data.

Site clearance and shallow hazard surveys will be completed to confirm the seafloor has soil and surface characteristics that will support the safe set-down of a drill rig, and long term occupation of the site by a vessel. Acoustic instrumentation to be used for the proposed survey is designed to characterize the seabed topography, bathymetry, potential geohazards, and other seafloor features (e.g., boulders) using seafloor imaging, water depth measurements, and high- resolution

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seismic profiling. The proposed site clearance and shallow hazard surveys will use the following methods: seafloor imaging, bathymetry, and high resolution seismic profiling.

Seafloor Imagery

Seafloor imagery would use a side-scan sonar, which is a sideward looking, two channel, narrow beam instrument that emits a sound pulse and listens for its return. The sound energy transmitted is in the shape of a cone that sweeps the sea floor resulting in a two dimensional image that produces a detailed representation of the seafloor and any features or objects on it. The sonar can either be hull mounted or towed behind the vessel. One of the following systems would be used in the proposed shallow hazard surveys:

(1) Marine Sonics Technology multi-frequency side-scan sonar: The frequency the side-scan sonar emits during operation can be varied from 150 - 1,200 kilohertz (kHz). It is expected that the frequency for this acquisition will be in the 150 kHz range. The pulse length is variable from 20 - 300 milliseconds (msec).

(2) EdgeTech 4200 dual-frequency side scan sonar: The side-scan sonar emits sound at frequency of 120 kHz during operation, occasionally reaching frequencies up to 410 kHz. The pulse length is up to 20 miliseconds (msec), and the source level is approximately 210 dB re 1 microPa-m (rms).

(3) Klein System 3000 dual-frequency digital side scan sonar: This side scan sonar would typically be run at the 132 kHz frequency band.

However, the 445 kHz frequency may be used periodically during exploratory testing. The transmission pulse is variable from 25 msec to 400 msec. The peak in the 132 kHz source level beam reaches 234 dB re 1 microPa-m. The peak in the 445 kHz source level beam reaches 242 dB re 1 microPa-m.

Bathymetry

Echo sounders for measuring water depth are generally mounted to the ship hull or on a side-mounted pole. Two different echo sounding systems will be used to provide bathymetric data during the proposed

Chukchi Sea shallow hazard surveys.

(1) Odom Hydrotrac Digital Echo Sounder: This device is a single beam echo sounder, which emits a single pulse of sound directly below the ship along the vessel trackline and provides a continuous recording of water depth along the survey track. Generally these records require heave compensation to rectify the data point. The Hydrotrac sonar operates at a frequency of 200 kHz and emits approximately 15 pulses per sec. Each pulse phase is between 0.03 and 0.12 msec. The peak within the source beam level transmits from 202 to 215 dB re 1 microPa- m.

(2) Reson Seabat 8101 Multibeam Echo Sounder: This echo sounder consists of a transducer array that emits a swath of sound. The seafloor coverage swath of the multibeam sonar is water depth dependent, but is usually equal to two to four times the water depth.

This sonar operates at a frequency of 240 kHz. It emits approximately 15 pulses per sec with each pulse duration lasting 21 msec to 225 msec for a swath that can cover up to 500 m (1,640 ft) in width. The peak in the source beam level for the Reson Seabat sonar transmits at 210 dB re 1 microPa-m. The multibeam system requires additional non-acoustic equipment including a motion sensor to measure heave, roll, and pitch, a gyrocompass, and a sound velocity probe. A TSSDMS-05 Dynamic Motion

Sensor, Hemisphere VS-110 Global Positioning System (GPS)/Heading

System and a Seabird SBE-19 CTD or Odom Digibar Pro will provide these data. The resulting multibeam data will provide a three dimensional (3-

D) view of the seafloor in the measured area.

High Resolution Seismic Profiling

An integral part of the shallow hazards and site clearance surveys is high-resolution seismic profiling using three different acoustic source systems. Seismic systems operate on the principal that an acoustic impulse will reflect part of its energy upon encountering a density interface. This will be accomplished through the use of a high- frequency subbottom profiler, an intermediate-frequency seismic profiling system, and a multichannel seismic system. The high- resolution profiling systems, which use smaller acoustic sources, will be utilized as opposed to low-resolution systems or deep exploration seismic systems. The planned surveys are geared toward providing detail of the surficial and shallow subsurface geology and not toward hydrocarbon exploration. The planned high-resolution profiles will provide the detailed information that is not resolved in the deep seismic profiles. The following equipment will be utilized for the high resolution seismic profiling portion of the marine surveys.

(1) High Resolution Subbottom Profiler

A subbottom profiler is a high-frequency seismic system that will be used to map geologic features in the proposed survey areas. Many of the modern subbottom profilers are ``chirp'' systems which are frequency or pulse-rate modulated. This allows the energy, amplitude, and phase characteristics of the acoustic pulse to be precisely controlled. The 500 Hz to 13 kHz frequency in conjunction with the 10- watt to 4-kilowatt (kW) power output generally achieves 25 to 250 msec, or approximately 20 to 200 m (65 to 656 ft) of bottom penetration, detailing the near-surface strata and density layers with a resolution of 6 to 20 cm (2 to 8 in). The two-way travel time of the acoustic signal, from firing to receiving, is recorded and travel time measurements are subsequently applied to water column velocity information, system delays, and appropriate tow depth corrections to calculate water depths and/or depths to subsurface events. The degree of ocean bottom penetration is variable depending on properties of the bottom and near-surface materials, the output power, and carrier frequency. The subbottom profiler is often used to supplement higher energy seismic systems or coring data to obtain accurate profiles of large areas. One of the following subbottom profiler systems or equivalent will be used in the proposed marine surveys:

(A) Knudsen 320 BR sub-bottom profiling system: The sub-bottom profiler will be used in the 3.5 to 12 kHz frequency range. The transmission pulse length is programmable sweeps or user defined pings.

A typical pulse width is 28 - 36 msec. The pulse repetition rate is 4 pulses/sec - 12 pulses/sec.

(B) GeoAcoustics/GeoPulse sub-bottom profiling system: The subbottom profiler will be used in the 3.5 to 5 kHz frequency range.

Pulse cycles range from 1 to 32 cycles of the selected frequency.

During the survey, 3.5 kHz will likely be used, possibly up to 5 kHz, depending on the geology of the seafloor.

(C) GeoAcoustics GeoChirp II subbottom profiling system: The subbottom profiler has a frequency range of 0.5 to 13 kHz, which is programmable. The transmission pulse length is typically 32 msec programmable sweeps or user defined pings. The pulse repetition rate is 4 pulses/sec (at maximum) for a 32 msec chirp sweep or 10 pulses/sec for pinger waveforms.

All the subbottom profiler has a source level at approximately 214 dB re 1 microPa-m. The 160, 180, and 190 dB re microPa radii, in the beam below the transducer, would be 501 m (1,644 ft), 50 m (164 ft), and 16 m (52 ft), respectively, assuming spherical spreading.

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The corresponding distances for an animal in the horizontal direction of these transducers would be much smaller due to the direct downward beam pattern of the subbottom profilers. Therefore, the horizontal received levels of 180 and 190 dB re 1 microPa (rms) would be within much smaller radii than 50 m (164 ft) and 16 m (52 ft) when using one of the GeoAcoustics subbottom profilers, which have the highest downward source level. In addition, the pulse duration of these subbottom profilers is extremely short, in the order of tens to hundreds of msec, and the survey is constantly moving. Therefore, for a marine mammal to receive prolonged exposure, the animal has to stay in a very small zone of ensonification and keep with the vessel's speed, which is very unlikely. Moreover, any effects would be less for baleen whales due to the frequency range of the profilers. Therefore, the potential effects from the sub-bottom profilers to marine mammals would be negligible.

(2) Intermediate Frequency Seismic Profiling System

One intermediate-frequency seismic system is referred to as a

``Boomer.'' The boomer transducer is a mechanical means of generating enough sound energy to penetrate the subsurface sediments. Signals are reflected from the various bedding planes (density/velocity interfaces) and received by a single-channel hydrophone streamer. The sound reflections are converted into electrical impulses, filtered, and sent to a graphic recorder. The Boomer can effectively detail the upper 40 to 600 m (131 to 1,969 ft) of subbottom, outlining the fine strata and density layers that represent foundation formations for seafloor-based structures. The depth of seismic penetration obtained with this system is determined by the sediment type and the amount of initial discharged energy. In many instances, the presence of organic gas will attenuate the signal and mask any deeper reflections. The boomer systems will consist of one of the following:

(A) An Applied Acoustics Squid 2000 mini sparker ``Boomer'': The maximum energy input ranges from 600 - 2,500 Joules (J) per shot with a maximum power input of 2,500 J per shot. The maximum energy will be determined once penetration has been assessed in the field. A pulse length range of 1 - 5 msec is typical. The peak in the source level beam reaches 222 dB re 1 microPa-m at 600 J with a frequency range of 0.5 to 300 kHz.

(B) An Applied Acoustics Model AA300 Boomer plate with housing. The maximum energy input is 350 J per shot with a maximum power input of 1,000 J per shot. The maximum energy that would be used for these surveys is 300 J. The pulse length ranges from 150 to 400 msec with a reverberation of less than 1/10 of the initial pulse. The peak in the source level beam reaches 218 dB re 1 microPa-m at 300 J with a frequency range of 0.5 to 300 kHz. A Datasonics Model SPR-1200 seismic profiling system also known as a ``bubble pulser.'' It has an electromagnetic source. The frequency of the system is 400 Hz in a narrow band. The peak in the source-level beam reaches 200 dB re 1 microPa-m.

(3) Multichannel Seismic System

The multichannel seismic system sources will consist of an:

(A) Geo-Spark 1600 Sparker: Much like the boomer, the sparker is a mechanical means of generating enough sound energy to penetrate the subsurface sediments. The sparker has eight electrode modules which are evenly spaced which make up an array with a physical dimension of 1.6 x 2 m (5.2 x 6.6 ft). The number of electrodes used is user defined, which gives the Geo-Spark 1600 the capability of operating at 6 - 16

Kj. It is expected that the sparker will be operated in a range of 10- 16 Kj. The sparker is towed behind the vessel approximately 75 ft (23 m) on a catamaran style floatation system. The towed unit is connected to a Geo-Spark 16 Kj power supply located on the deck which can emit power output of 4000 - 16000 J. Signals from the sparker are reflected from the various bedding planes (density/velocity interfaces) and received by a multi-channel hydrophone streamer. These signal data are then recorded on disc or tape. The sparker can effectively detail the upper 1 sec of sub bottom at a peak output of 212 dB re 1 microPa. The depth of seismic penetration obtained with this system is determined by the sediment type and the amount of discharged energy.

(B) Ultra Shallow Water (USW) array composed of a 40-in\3\ seismic sound source with four 10-in\3\ Input/Output (I/O) sleeve guns. If desired, the power can also be reduced to 20 in\3\. The reflected energy will be received by a multi channel marine digital recording streamer system with 48 hydrophone channels located at intervals of 3.125 - 12.5 m (10 - 41 ft) along the length of the streamer. The sound source is expected to provide 1.5 to 3 sec of data, two-way travel time with a resolution of 10 msec. It operates at a frequency range of 20 to 200 Hz and a peak sound output of 196 dB re 1 microPa for all four guns combined. The frequency range that will be used in the proposed surveys will be between 20 Hz and 200 Hz, nominal. This tool is useful in finding shallow faults and amplitude anomalies.

Description of Marine Mammals in the Activity Area

In general, the marine mammal species under NMFS' management authority that occur in or near the proposed survey area within the

Chukchi Sea are the bowhead (Balaena mysticetus), gray (Eschrichtius robustus), humpback (Megaptera novaeangliae), minke (Balaenoptera acutorostrata), beluga (Delphinapterus leucas), and killer whales

(Orcinus orca); harbor porpoises (Phocoena phocoena); and the bearded

(Erignathus barbatus), ringed (Phoca hispida), spotted (P. largha), and ribbon seals (P. fasciata). Among these species, the bowhead, humpback, and fin whales are listed as ``Endangered'' under the Endangered

Species Act (ESA).

A detailed description of the biology, population estimates, and distribution and abundance of these species is provided in CPAI's IHA application. Additional information regarding the stock assessments of these species is in NMFS' Alaska Marine Mammal Stock Assessment Report

(Angliss and Outlaw, 2007), and can also be assessed via the following

URL link: http://www.nmfs.noaa.gov/pr/pdfs/sars/po2006.pdf.

ESA-listed species known to occur in the adjacent Bering Sea, include blue (B. musculus), North Pacific right (Eubalaena japonica), and sperm whales (Physeter macrocephalus); and Steller sea lion

(Eumetopias jubatus). However, these species are considered to be extra-limital or rare in the Chukchi and Beaufort Seas. Fin whales have been recently reported in the Chukchi Sea in 2007 (Green et al., 2007), but there is a very remote chance of interaction and potential impact.

Therefore, these species (Steller sea lion, and sperm, fin, blue, and northern right whale) are not discussed further under this IHA application.

The most numerous marine mammal species seasonally occurring in the

Chukchi Sea is the Pacific walrus (Odobenus rosmarus divergens). The polar bear (Ursus maritimus) is also found in the Chukchi Sea. However, these two marine mammal species fall under the management authority of the U.S. Fish and Wildlife Service (USFWS), and a separate application for an incidental take authorization for walrus and polar bears is being made to USFWS for the Chukchi Sea program.

Additional information on those species that are under NMFS' management authority within or near

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the proposed survey areas is presented below.

Bowhead Whales

The only bowhead whale found in the proposed project areas is the

Western Arctic stock bowhead whale, which is also known as the Bering-

Chukchi-Beaufort stock or Bering Sea stock, and they are the only bowhead stock present in U.S. waters. The majority of these bowhead whales migrates annually from wintering (November through March) areas in the northern Bering Sea, through the Chukchi Sea in the Spring

(March through June), to the Beaufort Sea where they spend much of the summer (mid-May through September) before returning again to Bering Sea in the fall (September through November) to overwinter (Braham et al., 1980; Moore and Reeves, 1993). Most of the year, bowheads are associated with sea ice (Moore and reeves, 1993). The bowhead spring migration follows fractures in the sea ice around the coast of Alaska.

During the summer, most bowhead whales are in relatively ice-free waters of the Beaufort Sea. Although some bowheads are found in the

Chukchi and Bering Seas in summer, these whales are thought to be a part of the expanding Western Arctic stock (Rugh et al., 2003). In the

Beaufort sea, distribution of bowhead whales is not uniform with respect to depth, and they are more often observed in continental slope

(201 - 2,000 m, or 659 - 6,562 ft, water depth) than in inner shelf ( 100 kHz) beyond the effective hearing range of most marine mammals likely be encountered (Richardson et al., 1995). However, the equipment proposed for the seismic profiling operate at a frequency range and sound level that could affect marine mammal behavior if they occur within a relatively close distance to the sound source (Richardson et al., 1995). In addition, given the direct downward beam pattern of these sonar systems coupled with the high-frequency characteristics of the signals, the horizontal received levels of 180 and 190 dB re 1 microPa (rms) would be much smaller when compared to those from the low-frequency airguns with similar source levels. Therefore, NMFS believes that effects of signals from sonar equipment to marine mammals are negligible.

Numbers of Marine Mammals Estimated to be Taken

All anticipated takes would be takes by Level B harassment, involving temporary changes in behavior. The proposed mitigation measures to be applied would prevent the possibility of injurious takes.

Take was calculated for the two areas of the study area using vessel-based density estimates. Few bowheads and no belugas were observed during the vessel surveys conducted in the Chukchi Sea by LGL et al. (2008), although the surveys used multiple vessels achieving substantial effort and coverage from early July to mid November. This result is generally consistent with the historic information, which shows that bowheads generally migrated through the Chukchi Sea to the

Beaufort Sea by mid-late June, and don't return until about late

October and November, probably reaching the region of the project area no earlier than late October (LGL et al., 2008). Similarly, most belugas migrate to the northern Chukchi Sea and westward into the

Beaufort Sea by mid to late July and return to the region of the project area in late October and November (Suydam et al., 2005).

Although LGL et al., (2008) did not observe belugas offshore in 2006 or 2007, they did encounter belugas along the coast in decreasing numbers from July to October/November during aerial surveys. LGL et al. (2008) also observed bowheads in the fall near Barrow during nearshore aerial surveys, suggesting the whales had not moved very far into Chukchi Sea at that time. While these data and the historic information suggest the take calculations are reasonable for belugas and bowheads, the take numbers have been adjusted to 10 animals for each species to account for the possible occurrence of more animals than estimated in the project area during operations due to an early freeze-up or other unanticipated changes in the environment. This adjustment is generally consistent with estimates based on less current densities used in past

IHAs for bowhead (0.0011/km\2\) and beluga (0.0034/km\2\) whales for late fall.

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The vessel-based density estimates for ringed and spotted seals were reported in the LGL et al. (2008) study as a combined estimate for the two species, since observers were not able to distinguish the two species in the open water. However, since typically ringed seals comprise almost 95 percent of the combined ringed/spotted seal sightings recorded during surveys in offshore waters of the Chukchi Sea during 1989 - 1991 were ringed seals (Brueggeman et al., 1990; 1991; 1992), the LGL et al. (2008) ringed/spotted seal data were corrected by applying 95 percent of the sightings as ringed, and 5 percent as spotted seals, respectively.

JASCO modeled the sound levels of different configurations of seismic profilers (10 kj and 16 kj sparkers, 10 in\3\ and 20 in\3\ 2- gun arrays, 40 cu\3\ single gun, and 10 in\3\ 4-gun array) and found the 4-gun array produced the highest sound levels. Therefore, all take estimates of marine mammals are calculated for the 4-gun array in this proposed activity, which reaches the 160 dB re 1 microPa sound level at 1.665 km (1.03 mi) from the source, the 180 dB re 1 microPa level at 115 m (377 ft), and the 190 dB level at 20 m (66 ft).

The average estimates of ``take'' were calculated by multiplying the expected average animal densities by the area of ensonification for the 160 dB re 1 microPa (rms). The area of ensonification was determined by multiplying the total proposed trackline of 5,300 km

(3,294 mi)(2,120 km, or 1,318 mi, in August; 2,120 km, or 1,318 mi, in

September; and 1,060 km, or 659 mi, in October) times 2 (both sides of the trackline) times the distance to the 160-dB isopleth. The distance to the 160-dB isopleth was estimated as approximately 1,665 m (5,463 ft) with a corresponding area of ensonification of 17,649 km2 (6,817 mi2).

Based on the calculation, it is estimated that up to approximately 10 bowhead, 37 gray, and 4 minke whales, 42 harbor porpoises, 1,379 ringed, 72 spotted, and 376 bearded seals would be affected by Level B behavioral harassment as a result of the proposed shallow hazard and site clearance surveys. These take numbers represent 0.09, 0.19, 0.06, 0.66, and 0.15 percent of the western Arctic stock of bowhead, eastern

North Pacific stock of gray whales, Bering Sea stock of harbor porpoise, and Alaska stocks of ringed and bearded seals in the Chukchi

Sea region, respectively. Since no accurate current population estimates of minke whales and spotted seals are available, a specific estimate of the percentage of Level B harassment of this species is undetermined. Nonetheless, it is very low relative to the affected species or stocks in the proposed project area because: (1) for the minke whales, the Chukchi Sea is not their typical habitat (visual surveys in 1999 and 2000 counted 810 and 1,003 minke whales in the central-eastern and southeastern Bering Sea, respectively, not including animals missed on the trackline, and animals submerged when the ship passed (Moore et al., 2002), therefore, the take estimate of 4 minke whale is small even in relation to these visual counts); and (2) for the spotted seal, the early population estimate of this species ranged from 335,000 - 450,000 seals (Burns, 1973), and there is no reason to believe that the population of this species has declined significantly.

In addition, a number of beluga, humpback, and killer whales, and ribbon seals could also be affected by Level B behavioral harassment as a result of the proposed marine surveys in the Chukchi Sea. However, since the occurrence of these marine mammals is very rare within the proposed project area during the late summer and fall in the Chukchi

Sea, take numbers cannot be estimated. However, for the same reason,

NMFS believes their take numbers would be much lower (including as a percentage of the affected species or stock) as compared to those marine mammals whose take numbers were calculated.

Potential Impacts to Subsistence Harvest of Marine Mammals

Subsistence hunting and fishing is historically, and continues to be, an essential aspect of Native life, especially in rural coastal villages. The Inupiat participate in subsistence hunting and fishing activities in and around the Chukchi Sea.

Alaska Natives, including the Inupiat, legally hunt several species of marine mammals. Communities that participate in subsistence activities potentially affected by seismic surveys within the proposed survey areas are Point Hope, Point Lay, Wainwright, and Barrow. Marine animals used for subsistence in the proposed area include: bowhead whales, beluga whales, ringed seals, spotted seals, bearded seals,

Pacific walrus, and polar bears. In each village, there are key subsistence species. Hunts for these animals occur during different seasons throughout the year. Depending upon the village's success of the hunt for a certain species, another species may become a priority in order to provide enough nourishment to sustain the village.

Point Hope residents subsistence hunt for bowhead and beluga whales, polar bears and walrus. Bowhead and beluga whales are hunted in the spring and early summer along the ice edge. Beluga whales may also be hunted later in the summer along the shore. Walrus are harvested in late spring and early summer, and polar bear are hunted from October to

April (MMS, 2007). Seals are available from October through June, but are harvested primarily during the winter months, from November through

March, due to the availability of other resources during the other periods of the year (MMS, 2007).

With Point Lay situated near Kasegaluk Lagoon, the community's main subsistence focus is on beluga whales. Seals are available year-round, and polar bears and walruses are normally hunted in the winter. Hunters typically travel to Barrow, Wainwright, or Point Hope to participate in bowhead whale harvest, but there is interest in reestablishing a local

Point Lay harvest.

Wainwright residents subsist on both beluga and bowhead whales in the spring and early summer. During these two seasons the chances of landing a whale are higher than during other seasons. Seals are hunted by this community year-round and polar bears are hunted in the winter.

Barrow residents' main subsistence focus is concentrated on biannual bowhead whale hunts. They hunt these whales during the spring and fall. Other animals, such as seals, walruses, and polar bears are hunted outside of the whaling season, but they are not the primary source of the subsistence harvest (URS Corporation, 2005).

The potential impact of the noise produced by the proposed survey on subsistence could be substantial. If bowhead or beluga whales are permanently deflected away from their migration path, there could be significant repercussions to the subsistence use villages. However, mitigation efforts will be put into action to minimize or avoid completely any adverse affects on all marine mammals.

As a mitigation measure to minimize or avoid any adverse effects to subsistence harvest, CPAI will meet with key native organizations responsible for managing marine mammals in the Arctic. In accordance with 50 CFR 126.104(a)(12), CPAI will meet with the Alaska Eskimo

Whaling Commission (AEWC) in the planning for the 2008 site clearance and shallow hazard survey and develop a Plan of Cooperation (POC). In addition, CPAI will consult subsistence committees and commissions as required by its OCS 193 Leases, and meet with the North Slope Borough

(NSB) as necessary. Meetings with other stakeholders will provide information on the time, location, and

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features of the seismic survey/operations, opportunities for involvement by local people, potential impacts to marine mammals, and mitigation measures to avoid or minimize impacts.

A number of actions will be taken by CPAI during the surveys to minimize any adverse effect on the availability of marine mammals for subsistence, which have been proposed in the CPAI application. They include the following:

(1) Site clearance and shallow hazard surveys will occur in areas considerably away from the villages during the hunting periods;

(2) Site clearance and shallow hazard surveys will follow procedures of changing vessel course, powering down, and shutting down acoustic equipment to minimize effects on the behavior of marine mammals and, therefore, effects on opportunities for harvest by local communities; and

(3) In the unlikely event that a hunter is encountered, operations will be managed to stay beyond any hunter encountered within 5 km (3.1 mi) of the vessel when shooting airguns.

The combination of the low volume air guns, timing, location, mitigation measures, and input from local communities and organization is expected to mitigate any adverse effect of the seismic surveys on availability of marine mammals for subsistence uses.

Potential Impacts on Habitat

The proposed site clearance surveys would not result in any permanent impact on habitats used by marine mammals, or to the food sources they use. The main impact issue associated with the proposed activity would be temporarily elevated noise levels and the associated direct effects on marine mammals, as discussed above.

Proposed Monitoring and Mitigation Measures

Monitoring

In order to reduce and minimize the potential impacts to marine mammals from the proposed site clearance surveys, NMFS proposes the following monitoring measures to be implemented for the proposed project in Chukchi Sea.

Marine mammal monitoring during the site clearance surveys would be conducted by qualified, NMFS-approved marine mammal observers (MMOs).

Vessel-based MMOs would be on board the seismic source vessel to ensure that no marine mammals would enter the relevant safety radii while noise-generating equipment is operating.

MMOs will alternate at 4-hour shifts to avoid fatigue. The vessel crew will also be instructed to assist in detecting marine mammals and implementing mitigation requirements (if practical). Before the start of a geophysical survey the crew will be given additional instruction on how to do so.

During daytime hours, the MMO(s) will scan the area around the vessel systematically with reticule binoculars (e.g., 7 50 Bushnell or equivalent) and with the naked eye. Laser range finders (Laser Tech laser rangefinder or equivalent) will also be available to assist with distance estimation. During darkness, NVDs (Night Vision Device) will be available (ATN NVG-7 or equivalent).

Mitigation

Proposed mitigation measures include (1) vessel speed or course alteration, provided that doing so will not compromise operational safety requirements, (2) acoustic equipment shut down, and (3) acoustic source ramp up.

(1) Speed or Course Alteration

If a marine mammal is detected outside the relevant safety zone but appears likely to enter it based on relative movement of the vessel and the animal, then if safety and survey objectives allow, the vessel speed and/or course would be adjusted to minimize the likelihood of the animal entering the safety zone.

(2) Shut down Procedures

If a marine mammal is detected within, or appears likely to enter, the relevant safety zone of the array in use, and if vessel course and/ or speed changes are impractical or will not be effective to prevent the animal from entering the safety zone, then the acoustic sources that relate to the seismic surveys would be shut down.

Following a shut down, acoustic equipment would not be turned on until the marine mammal is outside the safety zone. The animal would be considered to have cleared the safety zone if it (1) is visually observed to have left the 115-m (377-ft) or 20-m (66-ft) safety zone, for a cetacean or a pinniped species, respectively; or (2) has not been seen within the relevant safety zone for 15 min in the case of odontocetes or pinnipeds and 30 min in the case of mysticetes. These safety zones correspond to areas where the received SPLs are 180 and 190 dB re 1 microPa (rms), respectively.

Following a shut down and subsequent animal departure as above, the acoustic sources may be turned on to resume operations following ramp- up procedures described below.

(3) Ramp-up Procedures

A ramp-up procedure will be followed when the acoustic sources begin operating after a specified period without operations. It is proposed that, for the present survey, this period would be 30 min.

Ramp up would begin with the power on of the smallest acoustic equipment for the survey at its lowest power output. The power output would be gradually turned up and other acoustic sources would be added in a way such that the source level would increase in steps not exceeding 6 dB per 5-min period. During ramp-up, the MMOs would monitor the safety zone, and if marine mammals are sighted, decisions about course/speed changes and/or shutdown would be implemented as though the acoustic equipment is operating at full power.

Data Collection and Reporting

MMOs would record data to estimate the numbers of marine mammals present and to document apparent disturbance reactions or lack thereof.

Data would be used to estimate numbers of animals potentially ``taken'' by harassment. They would also provide information needed to order a shut down of acoustic equipment when marine mammals are within or entering the safety zone.

When a sighting is made, the following information about the sighting would be recorded:

(1) Species, group size, age/size/sex categories (if determinable), behavior when first sighted and after initial sighting, heading (if consistent), bearing and distance from seismic vessel, and apparent reaction to the acoustic sources or vessel.

(2) Time, location relative to the acoustic sources, heading, speed, activity of the vessel (including whether and the level at which acoustic sources are operating), sea state, visibility, and sun glare.

The data listed under (2) would also be recorded at the start and end of each observation watch, and during a watch whenever there is a change in one or more of the variables.

A final report will be submitted to NMFS within 90 days after the end of the shallow hazard and site clearance surveys. The report will describe the operations that were conducted and sightings of marine mammals near the operations. The report also will provide full documentation of methods, results, and interpretation pertaining to all monitoring. The report will summarize the dates and locations of seismic operations, and all marine mammal sightings (dates, times, locations,

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activities, associated seismic survey activities), and the amount and nature of potential take of marine mammals by harassment or in other ways.

Endangered Species Act

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

National Environmental Policy Act (NEPA)

In 2006, the MMS prepared Draft and Final Programmatic

Environmental Assessments (PEAs) for seismic surveys in the Beaufort and Chukchi Seas. NMFS was a cooperating agency in the preparation of the MMS PEA. On November 17, 2006, NMFS and MMS announced that they were jointly preparing a Draft Programmatic Environmental Impact

Statement (PEIS) to assess the impacts of MMS' annual authorizations under the Outer Continental Shelf (OCS) Lands Act to the U.S. oil and gas industry to conduct offshore geophysical seismic surveys in the

Chukchi and Beaufort seas off Alaska, and NMFS' authorizations under the MMPA to incidentally harass marine mammals while conducting those surveys. On March 30, 2007, the Environmental Protection Agency (EPA) noted the availability for comment of the NMFS/MMS Draft PEIS. A Final

PEIS has not been completed. Therefore, NMFS determined it will update the 2006 PEA in order to meet its NEPA requirements in the interim.

This approach is warranted because the five proposed Arctic seismic survey IHAs for 2008 fall within the scope of the effects analysis in the 2006 PEA. To update the 2006 Final PEA, NMFS is currently preparing a Supplemental EA which incorporates by reference the 2006 Final PEA and other related documents.

Preliminary Determination

Based on the preceding information, and provided that the proposed mitigation and monitoring are incorporated, NMFS has preliminarily determined that the impact of conducting the shallow hazard and site clearance surveys in Chukchi Sea may result, at worst, in a temporary modification in behavior of small numbers of certain species of marine mammals. While behavioral and avoidance reactions may be made by these species in response to the resultant noise from the airguns, side-scan sonars, seismic profilers, and other acoustic equipment, these behavioral changes are expected to have a negligible impact on the affected species and stocks of marine mammals, and no unmitigable adverse impact on their availability for subsistence.

While the number of potential incidental harassment takes will depend on the distribution and abundance of marine mammals in the area of site clearance operations, the number of potential harassment takings is estimated to be relatively small in light of the population size. NMFS anticipates the actual take of individuals to be lower than the numbers presented in the analysis because those numbers do not reflect either the implementation of the mitigation measures or the fact that some animals will avoid the sound at levels lower than those expected to result in harassment.

In addition, no take by death and/or injury is anticipated, and the potential for temporary or permanent hearing impairment will be avoided through the incorporation of the required mitigation measures described in this document. This determination is supported by (1) the likelihood that, given sufficient notice through slow ship speed and ramp-up of the acoustic equipment, marine mammals are expected to move away from a noise source that it is annoying prior to its becoming potentially injurious; (2) TTS is unlikely to occur, especially in odontocetes, until levels above 180 dB re 1 microPa (rms) are reached; and (3) the fact that injurious levels of sound are only likely very close to the vessel.

Proposed Authorization

NMFS proposes to issue an IHA to CPAI for shallow hazard and site clearance surveys in Chukchi Sea between August and October 2008, provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated.

Dated: May 16, 2008.

Helen Golde,

Deputy Director, Office of Protected Resources, National Marine

Fisheries Service.

FR Doc. E8-11537 Filed 5-22-08; 8:45 am

BILLING CODE 3510-22-S

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