`[Federal Register Volume 75, Number 109 (Tuesday, June 8, 2010)]
[Notices]
[Pages 32379-32398]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2010-13753]





[[Page 32379]]



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DEPARTMENT OF COMMERCE



National Oceanic and Atmospheric Administration



RIN 0648-XW13




Takes of Marine Mammals Incidental to Specified Activities; 

Taking Marine Mammals Incidental to Open Water Marine Seismic Survey in 

the Chukchi Sea, Alaska



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

Atmospheric Administration (NOAA), Commerce.



ACTION:  Notice; proposed incidental harassment authorization; request 

for comments.



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SUMMARY: NMFS received an application from Statoil USA E&P Inc. 

(Statoil) for an Incidental Harassment Authorization (IHA) to take 

marine mammals, by harassment, incidental to a proposed open water 

marine seismic survey in the Chukchi Sea, Alaska, between July through 

November 2010. Pursuant to the Marine Mammal Protection Act (MMPA), 

NMFS is requesting comments on its proposal to issue an IHA to Statoil 

to take, by Level B harassment only, twelve species of marine mammals 

during the specified activity.



DATES:  Comments and information must be received no later than July 8, 

2010.



ADDRESSES:  Comments on the application should be addressed to Michael 

Payne, Chief, Permits, Conservation and Education Division, Office of 

Protected Resources, National Marine Fisheries Service, 1315 East West 

Highway, Silver Spring, MD 20910. The mailbox address for providing 

email comments is [email protected]. 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.

    Instructions: All comments received are a part of the public record 

and will generally be posted to http://www.nmfs.noaa.gov/pr/permits/incidental.htm without change. All Personal Identifying Information 

(for example, name, address, etc.) voluntarily submitted by the 

commenter may be publicly accessible. Do not submit Confidential 

Business Information or otherwise sensitive or protected information.

    A copy of the application 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 also 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 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, a notice of a proposed authorization is 

provided to the public for review.

    Authorization for incidental takings shall be granted if NMFS finds 

that the taking will have a negligible impact on the species or 

stock(s), will not have an unmitigable adverse impact on the 

availability of the species or stock(s) for subsistence uses (where 

relevant), 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 U.S. can apply for an authorization to 

incidentally take small numbers of marine mammals by harassment. 

Section 101(a)(5)(D) establishes a 45 day time limit for NMFS review of 

an application followed by a 30 day public notice and comment period on 

any proposed authorizations for the incidental harassment of marine 

mammals. Within 45 days of the close of the comment period, NMFS must 

either issue or deny the authorization.

    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''].



Summary of Request



    NMFS received an application on December 24, 2009, from Statoil for 

the taking, by harassment, of marine mammals incidental to a 3D marine 

seismic surveys in the Chukchi Sea, Alaska, during the 2010 open-water 

season. After addressing comments from NMFS, Statoil modified its 

application and submitted a revised application on April 12, 2010. The 

April 12, 2010, application is the one available for public comment 

(see ADDRESSES) and considered by NMFS for this proposed IHA.

    This proposed marine seismic survey will use two towed airgun array 

consisting of 26 active (10 spare) airguns with a maximum discharge 

volume of 3,000 cubic inch (in\3\). The proposed 3D survey will take 

place in a 915 mi\2\ (2,370 km\2\) survey area approximately 150 mi 

(241 km) west of Barrow in water depth of approximately 100 to 165 ft 

(30 to 50 m). The seismic survey is designed to collect 3D data of the 

deep sub-surface in Statoil's Chukchi leases in support of future oil 

and gas development within the area of coverage. The data will help 

identify source rocks, migration pathways, and play types. In addition, 

a 2D tie line survey has been designed as a second priority program to 

acquire useful information in the region. The four stand alone 2D lines 

(with a total length of approximately 420 mi or 675 km) are designed to 

tie the details of the new high resolution 3D image to the surrounding 

regional geology to facilitate interpretation of more regional trends. 

The number of 2D km acquired will to some degree be dependent on the 

2010 season's restrictive ice coverage and the 3D data acquisition 

progress.

    Statoil intends to conduct these marine surveys during the 2010 

Arctic open-water season (July through November). Impacts to marine 

mammals may occur from noise produced by airgun sources used in the 

surveys.



Description of the Specified Activity



    Statoil plans to conduct geophysical data acquisition activities in 

the Chukchi Sea in the period July 15 through November 30, 2010. Data 

acquisition is expected to take approximately 60 days (including 

anticipated downtime), but the total period for this request is from 

July 15 through November 30 to allow for unexpected downtime. The 

project area



[[Page 32380]]



encompasses approximately 915 mi\2\ (2,370 km\2\) in Statoil lease 

holdings in the Minerals Management Service (MMS) Outer Continental 

Shelf (OCS) Lease Sale 193 area in the northern Chukchi Sea (Figure 1 

of the Statoil IHA application). The activities consist of 3D seismic 

data acquisition and a 2D tie line survey as a second priority program.

    The entire 3D program, if it can be completed, will consist of 

approximately 3,100 mi (4,990 km) of production line, not including 

line turns. A total of four 2D well tie lines with a total length of 

approximately 420 mi (675 km) are included in the survey plan as a 

second priority program. The 3D seismic data acquisition will be 

conducted from the M/V Geo Celtic. The M/V Geo Celtic will tow two 

identical airgun arrays at approximately 20 ft (6 m) depth and at a 

distance of about 902 ft (275 m) behind the vessel. Each array is 

composed of three strings for a total of 26 active G-guns (4 60 in\3\, 

8 70 in\3\, 6 100 in\3\, 4 150 in\3\, and 4 250 in\3\) with a total 

discharge volume of 3000 in\3\. Each array also consists of 5 clusters 

of 10 inactive airguns that will be used as spares. One of the smallest 

guns in the array (60 in\3\) will be used as the mitigation gun. More 

details of the airgun array and its components are described in 

Appendix B of Statoil's IHA application. In addition to the airgun 

array, pinger systems (DigiRANGE II, or similar systems) will be used 

to position the streamer array relative to the vessel.

    The estimated source level for the full 3000 in\3\ array is 245 dB 

re 1 microPa (rms) at 1 m. The maximum distances to received levels of 

190, 180 160, and 120 dB re 1 microPa (rms) from sound source 

verification (SSV) measurements of the 3,147 in\3\ airgun array used in 

the Chukchi Sea during 2006-2008 were used to model the received levels 

at these distances, which show that the maximum distances are 700, 

2,500, 13,000, and 120,000 m, respectively.

    The estimated source level of this single 60 in\3\ airgun is 230 dB 

re 1 microPa (rms) at 1 m, and the modeled distances to received levels 

of 190, 180 160, and 120 dB re 1 microPa (rms) are 75, 220, 1,800, and 

50,000 m, respectively.

    The DigiRANGE II pinger system produces very short pulses, 

occurring for 10 ms, with source level approximately 180 dB re 1 

microPa (rms) at 1 m at 55 kHz, 188 dB re 1 microPa (rms) at 1 m at 75 

kHz, and 184 dB re 1 microPa (rms) at 1 m at 95 kHz. One pulse is 

emitted on command from the operator aboard the source vessel, which 

under normal operating conditions is once every 10 s. Most of the 

energy in the sound pulses emitted by this pinger is between 50 and 100 

kHz. The signal is omnidirectional. Using simple spherical spreading 

modeling for sound propagation, the calculated distances to received 

levels of 180, 160, and 120 dB re 1 microPa (rms) are 2.5 m, 25 m, and 

2,512 m, respectively. These distances are well within the radii for 

airgun arrays and that of a single mitigation gun.

    The vessel will travel along pre-determined lines at a speed of 

about 4 - 5 knots while one of the airgun arrays discharges every 8 - 

10 seconds (shot interval 61.52 ft [18.75 m]). The streamer hydrophone 

array will consist of twelve streamers of up to approximately 2.2 mi (4 

km) in length, with a total of 20,000 - 25,000 hydrophones at 6.6 ft (2 

m) spacing. This large hydrophone streamer receiver array, designed to 

maximize efficiency and minimize the number of source points, will 

receive the reflected signals from the airgun array and transfer the 

data to an on-board processing system.

    A 2D tie line survey has been designed as a second priority program 

to allow the vessel to acquire useful information in the region. The 

four stand alone 2D lines have a total length of approximately 420 mi 

(675 km) and are designed to tie the details of the new high resolution 

3D image to known surrounding regional geology.

    The approximate boundaries of the total surface area are between 

71[deg] 30' N and 72[deg] 00' N and between 165[deg] W and 162[deg] 30' 

W. The water depth in the survey area varies from 100 to 165 ft (30 to 

50 m).

    The vessels involved in the seismic survey activities will consist 

of at least three vessels as listed below. Specifications of these 

vessels (or equivalent vessels if availability changes) are provided in 

Appendix A of Statoil's IHA application.

     One (1) seismic source vessel, the M/V Geo Celtic or 

similar equipped vessel, to tow the two 3,000 in\3\ airgun arrays and 

hydrophone streamer for the 3D (and 2D) seismic data acquisition and to 

serve as a platform for marine mammal monitoring;

     One (1) chase/monitoring vessel, the M/V Gulf Provider or 

similar equipped vessel, for marine mammal monitoring, crew transfer, 

support and supply duties.

     One (1) chase/monitoring vessel, the M/V Thor Alpha or 

similar equipped vessel, for marine mammal monitoring, support and 

supply duties.

    The M/V Geo Celtic, or similar vessel, will arrive in Dutch Harbor 

around mid July 2010. The vessels will be resupplied and the crew 

changed at this port. Depending on ice conditions, all three vessels 

will depart Dutch Harbor around mid/end July with an expected transit 

time of approximately 5 days (weather depending). Directly upon arrival 

in the 3D survey area, depending on ice conditions, the M/V Geo Celtic 

will deploy the airgun array and start operating their guns for the 

purpose of sound source verification measurements (see Statoil IHA 

application for more details). The startup date of seismic data 

acquisition is expected to be early/mid August but depends on local ice 

conditions.

    Upon completion of these measurements the seismic data acquisition 

in the Chukchi Sea will start and, depending on the start date, is 

expected to be completed in the first half of October. This is based on 

an estimated duration of 60 days from first to last shot point 

(including anticipated downtime). The data acquisition is a 24-hour 

operation.



Description of Marine Mammals in the Area of the Specified Activity



    Eight cetacean and four pinniped species under NMFS jurisdiction 

could occur in the general area of Statoil's open water marine seismic 

survey area in the Chukchi Sea. These species most likely to occur in 

the general area project vicinity include two cetacean species: beluga 

(Delphinapterus leucas) and bowhead whales (Balaena mysticetus), and 

three seal species: ringed (Phoca hispida), spotted (P. largha), and 

bearded seals (Erignathus barbatus). Most encounters are likely to 

occur in nearshore shelf habitats or along the ice edge. The marine 

mammal species that is likely to be encountered most widely (in space 

and time) throughout the period of the open water seismic survey is the 

ringed seal. Encounters with bowhead and beluga whales are expected to 

be limited to particular regions and seasons, as discussed below.

    Other marine mammal species that have been observed in the Chukchi 

Sea but are less frequent or uncommon in the project area include 

harbor porpoise (Phocoena phocoena), narwhal (Monodon monoceros), 

killer whale (Orcinus orca), fin whale (Balaenoptera physalus), minke 

whale (B. acutorostrata), humpback whale (Megaptera novaeangliae), gray 

whale (Eschrichtius robustus), and ribbon seal (Histriophoca fasciata). 

These species could occur in the project area, but each of these 

species is uncommon or rare in the area and relatively few encounters 

with these species are expected during the proposed marine seismic 

survey. The narwhal occurs in Canadian waters



[[Page 32381]]



and occasionally in the Beaufort Sea, but it is rare there and is not 

expected to be encountered. There are scattered records of narwhal in 

Alaskan waters, including reports by subsistence hunters, where the 

species is considered extralimital (Reeves et al. 2002). Point Barrow, 

Alaska, is the approximate northeastern extent of the harbor porpoise's 

regular range (Suydam and George 1992). Humpback, fin, and minke whales 

have recently been sighted in the Chukchi Sea but very rarely in the 

Beaufort Sea. Greene et al. (2007) reported and photographed a humpback 

whale cow/calf pair east of Barrow near Smith Bay in 2007, which is the 

first known occurrence of humpbacks in the Beaufort Sea. Savarese et 

al. (2009) reported one minke whale sighting in the Beaufort Sea in 

2007 and 2008. Ribbon seals do not normally occur in the Beaufort Sea; 

however, two ribbon seal sightings were reported during vessel-based 

activities near Prudhoe Bay in 2008 (Savarese et al. 2009).

    The bowhead, fin, and humpback whales are listed as ``endangered'' 

under the Endangered Species Act (ESA) and as depleted under the MMPA. 

Certain stocks or populations of gray, beluga, and killer whales and 

spotted seals are listed as endangered or proposed for listing under 

the ESA; however, none of those stocks or populations occur in the 

proposed activity area. Additionally, the ribbon seal is considered a 

``species of concern'' under the ESA, and the bearded and ringed seals 

are ``candidate species'' under the ESA, meaning they are currently 

being considered for listing.

    Statoil's application contains information on the status, 

distribution, seasonal distribution, and abundance of each of the 

species under NMFS jurisdiction mentioned in this document. Please 

refer to the application for that information (see ADDRESSES). 

Additional information can also be found in the NMFS Stock Assessment 

Reports (SAR). The Alaska 2009 SAR is available at: http://www.nmfs.noaa.gov/pr/pdfs/sars/ak2009.pdf.



Potential Effects of the Specified Activity on Marine Mammals



    Operating active acoustic sources such as an airgun array has the 

potential for adverse effects on marine mammals.



Potential Effects of Airgun Sounds on Marine Mammals



    The effects of sounds from airgun pulses might include one or more 

of the following: tolerance, masking of natural sounds, behavioral 

disturbance, and temporary or permanent hearing impairment or non-

auditory effects (Richardson et al. 1995). As outlined in previous NMFS 

documents, the effects of noise on marine mammals are highly variable, 

and can be categorized as follows (based on Richardson et al. 1995):

(1) Tolerance

    Numerous studies have shown that pulsed sounds from airguns are 

often readily detectable in the water at distances of many kilometers. 

Numerous studies have shown that marine mammals at distances more than 

a few kilometers from operating seismic vessels often show no apparent 

response. That is often true even in cases when the pulsed sounds must 

be readily audible to the animals based on measured received levels and 

the hearing sensitivity of that mammal group. Although various baleen 

whales, toothed whales, and (less frequently) pinnipeds have been shown 

to react behaviorally to airgun pulses under some conditions, at other 

times, mammals of all three types have shown no overt reactions. In 

general, pinnipeds and small odontocetes seem to be more tolerant of 

exposure to airgun pulses than baleen whales.

(2) Behavioral Disturbance

    Marine mammals may behaviorally react to sound when exposed to 

anthropogenic noise. These behavioral reactions are often shown as: 

changing durations of surfacing and dives, number of blows per 

surfacing, or moving direction and/or speed; reduced/increased vocal 

activities, changing/cessation of certain behavioral activities (such 

as socializing or feeding); visible startle response or aggressive 

behavior (such as tail/fluke slapping or jaw clapping), avoidance of 

areas where noise sources are located, and/or flight responses (e.g., 

pinnipeds flushing into water from haulouts or rookeries).

    The biological significance of many of these behavioral 

disturbances is difficult to predict, especially if the detected 

disturbances appear minor. However, the consequences of behavioral 

modification could be expected to be biologically significant if the 

change affects growth, survival, and reproduction. Some of these 

significant behavioral modifications include:

     Drastic change in diving/surfacing patterns (such as those 

thought to be causing beaked whale stranding due to exposure to 

military mid-frequency tactical sonar);

     Habitat abandonment due to loss of desirable acoustic 

environment; and

     Cease feeding or social interaction.

    The onset of behavioral disturbance from anthropogenic noise 

depends on both external factors (characteristics of noise sources and 

their paths) and the receiving animals (hearing, motivation, 

experience, demography) and is also difficult to predict (Southall et 

al. 2007).

    Currently NMFS uses 160 dB re 1 microPa at received level for 

impulse noises (such as airgun pulses) as the onset of marine mammal 

behavioral harassment.

(3) Masking

    Chronic exposure to excessive, though not high-intensity, noise 

could cause masking at particular frequencies for marine mammals that 

utilize sound for vital biological functions. Masking can interfere 

with detection of acoustic signals such as communication calls, 

echolocation sounds, and environmental sounds important to marine 

mammals. Since marine mammals depend on acoustic cues for vital 

biological functions, such as orientation, communication, finding prey, 

and avoiding predators, marine mammals that experience severe acoustic 

masking will have reduced fitness in survival and reproduction.

    Masking occurs when noise and signals (that animal utilizes) 

overlap at both spectral and temporal scales. For the airgun noise 

generated from the proposed marine seismic survey, these are low 

frequency (under 1 kHz) pulses with extremely short durations (in the 

scale of milliseconds). Lower frequency man-made noises are more likely 

to affect detection of communication calls and other potentially 

important natural sounds such as surf and prey noise. There is little 

concern regarding masking due to the brief duration of these pulses and 

relatively longer silence between airgun shots (9 - 12 seconds) near 

the noise source, however, at long distances (over tens of kilometers 

away), due to multipath propagation and reverberation, the durations of 

airgun pulses can be ``stretched'' to seconds with long decays (Madsen 

et al. 2006). Therefore it could affect communication signals used by 

low frequency mysticetes when they occur near the noise band and thus 

reduce the communication space of animals (e.g., Clark et al. 2009) and 

cause increased stress levels (e.g., Foote et al. 2004; Holt et al. 

2009). Nevertheless, the intensity of the noise is also greatly reduced 

at such long distances (for example, the modeled received level drops 

below 120 dB re 1 microPa rms at 14,900 m from the source).

    Marine mammals are thought to be able to compensate for masking by 

adjusting their acoustic behavior such as



[[Page 32382]]



shifting call frequencies, increasing call volume and vocalization 

rates. For example, blue whales are found to increase call rates when 

exposed to seismic survey noise in the St. Lawrence Estuary (Di Iorio 

and Clark 2010). The North Atlantic right whales (Eubalaena glacialis) 

exposed to high shipping noise increase call frequency (Parks et al. 

2007), while some humpback whales respond to low-frequency active sonar 

playbacks by increasing song length (Miller el al. 2000).

(4) Hearing Impairment

    Marine mammals exposed to high intensity sound repeatedly or for 

prolonged periods can experience hearing threshold shift (TS), which is 

the loss of hearing sensitivity at certain frequency ranges (Kastak et 

al. 1999; Schlundt et al. 2000; Finneran et al. 2002; 2005). TS can be 

permanent (PTS), in which case the loss of hearing sensitivity is 

unrecoverable, or temporary (TTS), in which case the animal's hearing 

threshold will recover over time (Southall et al. 2007). Just like 

masking, marine mammals that suffer from PTS or TTS will have reduced 

fitness in survival and reproduction, either permanently or 

temporarily. Repeated noise exposure that leads to TTS could cause PTS. 

For transient sounds, the sound level necessary to cause TTS is 

inversely related to the duration of the sound.

    Experiments on a bottlenose dolphin (Tursiops truncates) and beluga 

whale showed that exposure to a single watergun impulse at a received 

level of 207 kPa (or 30 psi) peak-to-peak (p-p), which is equivalent to 

228 dB re 1 microPa (p-p), resulted in a 7 and 6 dB TTS in the beluga 

whale at 0.4 and 30 kHz, respectively. Thresholds returned to within 2 

dB of the pre-exposure level within 4 minutes of the exposure (Finneran 

et al. 2002). No TTS was observed in the bottlenose dolphin. Although 

the source level of pile driving from one hammer strike is expected to 

be much lower than the single watergun impulse cited here, animals 

being exposed for a prolonged period to repeated hammer strikes could 

receive more noise exposure in terms of SEL than from the single 

watergun impulse (estimated at 188 dB re 1 microPa2-s) in the 

aforementioned experiment (Finneran et al. 2002).

    For baleen whales, there are no data, direct or indirect, on levels 

or properties of sound that are required to induce TTS. The frequencies 

to which baleen whales are most sensitive are lower than those to which 

odontocetes are most sensitive, and natural ambient noise levels at 

those low frequencies tend to be higher (Urick 1983). As a result, 

auditory thresholds of baleen whales within their frequency band of 

best hearing are believed to be higher (less sensitive) than are those 

of odontocetes at their best frequencies (Clark and Ellison, 2004). 

From this, it is suspected that received levels causing TTS onset may 

also be higher in baleen whales. However, no cases of TTS are expected 

given the small size of the airguns proposed to be used and the strong 

likelihood that baleen whales (especially migrating bowheads) would 

avoid the approaching airguns (or vessel) before being exposed to 

levels high enough for there to be any possibility of TTS.

    In pinnipeds, TTS thresholds associated with exposure to brief 

pulses (single or multiple) of underwater sound have not been measured. 

Initial evidence from prolonged exposures suggested that some pinnipeds 

may incur TTS at somewhat lower received levels than do small 

odontocetes exposed for similar durations (Kastak et al. 1999, 2005; 

Ketten et al. 2001). However, more recent indications are that TTS 

onset in the most sensitive pinniped species studied (harbor seal, 

which is closely related to the ringed seal) may occur at a similar SEL 

as in odontocetes (Kastak et al., 2004).

    NMFS (1995, 2000) concluded that cetaceans and pinnipeds should not 

be exposed to pulsed underwater noise at received levels exceeding, 

respectively, 180 and 190 dB re 1 microPa rms. The established 180- and 

190-dB re 1 microPa rms criteria are not considered to be the levels 

above which TTS might occur. Rather, they are the received levels above 

which, in the view of a panel of bioacoustics specialists convened by 

NMFS before TTS measurements for marine mammals started to become 

available, one could not be certain that there would be no injurious 

effects, auditory or otherwise, to marine mammals. As summarized above, 

data that are now available to imply that TTS is unlikely to occur 

unless bow-riding odontocetes are exposed to airgun pulses much 

stronger than 180 dB re 1 microPa rms (Southall et al. 2007).

    No cases of TTS are expected as a result of Statoil's proposed 

seismic activity due to the fact that much higher received levels than 

180- and 190-dB would be needed to induce TTS. In addition, the strong 

likelihood that baleen whales (especially migrating bowheads) would 

avoid the approaching airguns (or vessel) before being exposed to 

levels high enough for there to be any possibility of TTS, and the 

mitigation and monitoring measures prescribed (described below in the 

document) will largely prevent marine mammals from being exposed to SPL 

above 180 and 190 dB re 1 microPa (rms).

    There is no empirical evidence that exposure to pulses of airgun 

sound can cause PTS in any marine mammal, even with large arrays of 

airguns (see Southall et al., 2007). However, given the possibility 

that mammals close to an airgun array might incur TTS, there has been 

further speculation about the possibility that some individuals 

occurring very close to airguns might incur PTS. Single or occasional 

occurrences of mild TTS are not indicative of permanent auditory damage 

in terrestrial mammals. Relationships between TTS and PTS thresholds 

have not been studied in marine mammals, but are assumed to be similar 

to those in humans and other terrestrial mammals. That is, PTS might 

occur at a received sound level magnitudes higher than the level of 

onset TTS, or by repeated exposure to the levels that cause TTS. 

Therefore, by means of preventing the onset of TTS, it is highly 

unlikely that marine mammals could receive sounds strong enough (and 

over a sufficient duration) to cause permanent hearing impairment 

during the proposed marine seismic survey in the Chukchi Sea.

(5) Non-auditory Physical Effects

    Non-auditory physical effects might occur in marine mammals exposed 

to strong underwater pulsed sound. Possible types of non-auditory 

physiological effects or injuries that theoretically might occur in 

mammals close to a strong sound source include stress, neurological 

effects, bubble formation, and other types of organ or tissue damage. 

Some marine mammal species (i.e., beaked whales) may be especially 

susceptible to injury and/or stranding when exposed to strong pulsed 

sounds. However, there is no definitive evidence that any of these 

effects occur even for marine mammals in close proximity to large 

arrays of airguns, and beaked whales do not occur in the proposed 

project area. In addition, marine mammals that show behavioral 

avoidance of seismic vessels, including most baleen whales, some 

odontocetes (including belugas), and some pinnipeds, are especially 

unlikely to incur non-auditory impairment or other physical effects.

(6) Stranding and Mortality

    Marine mammals close to underwater detonations of high explosive 

can be killed or severely injured, and the auditory organs are 

especially susceptible to injury (Ketten et al. 1993; Ketten 1995). 

Airgun pulses are less



[[Page 32383]]



energetic and their peak amplitudes have slower rise times. Up-to-date, 

there is no evidence that serious injury, death, or stranding by marine 

mammals can occur from exposure to airgun pulses, even in the case of 

large airgun arrays.

    However, in numerous past IHA notices for seismic surveys, 

commenters have referenced two stranding events allegedly associated 

with seismic activities, one off Baja California and a second off 

Brazil. NMFS has addressed this concern several times, and, without new 

information, does not believe that this issue warrants further 

discussion. For information relevant to strandings of marine mammals, 

readers are encouraged to review NMFS' response to comments on this 

matter found in 69 FR 74905 (December 14, 2004), 71 FR 43112 (July 31, 

2006), 71 FR 50027 (August 24, 2006), and 71 FR 49418 (August 23, 

2006). In addition, a May-June 2008, stranding of 100-200 melon-headed 

whales (Peponocephala electra) off Madagascar that appears to be 

associated with seismic surveys is currently under investigation (IWC 

2009).

    It should be noted that strandings related to sound exposure have 

not been recorded for marine mammal species in the Beaufort and Chukchi 

seas. NMFS notes that in the Beaufort Sea, aerial surveys have been 

conducted by MMS and industry during periods of industrial activity 

(and by MMS during times with no activity). No strandings or marine 

mammals in distress have been observed during these surveys and none 

have been reported by North Slope Borough inhabitants. As a result, 

NMFS does not expect any marine mammals will incur serious injury or 

mortality in the Arctic Ocean or strand as a result of proposed seismic 

survey.



Potential Effects from Pinger System on Marine Mammals



    A pinger system (DigiRANGE II) will be used during seismic 

operations to position the airgun array and hydrophone streamer 

relative to the vessel. The specifications of the DigiRANGE II pinger 

system (source levels and frequency ranges) are provided above. The 

pinger produces sounds that are above the range of frequencies produced 

or heard by mysticetes. However, the beluga whales and other 

odontocetes have good hearing sensitivity across the pingers major 

frequency range, which is at 50 - 100 kHz (Au et al. 1978; Johnson et 

al. 1989). Some seals also can hear sounds at frequencies up to 

somewhat above 55 kHz. In general, the potential effects of the pulse 

pinger on marine mammals are similar to those from the airgun, but the 

magnitude of the impacts is expected to be much less due to much lower 

intensity and higher frequencies. Estimated source levels and zones of 

influence from the pinger system are discussed above.



Vessel Sounds



    In addition to the noise generated from seismic airguns, various 

types of vessels will be used in the operations, including source 

vessels and support vessels. Sounds from boats and vessels have been 

reported extensively (Greene and Moore 1995; Blackwell and Greene 2002; 

2005; 2006). Numerous measurements of underwater vessel sound have been 

performed in support of recent industry activity in the Chukchi and 

Beaufort Seas. Results of these measurements were reported in various 

90-day and comprehensive reports since 2007 (e.g., Aerts et al. 2008; 

Hauser et al. 2008; Brueggeman 2009; Ireland et al. 2009). For example, 

Garner and Hannay (2009) estimated sound pressure levels of 100 dB at 

distances ranging from approximately 1.5 to 2.3 mi (2.4 to 3.7 km) from 

various types of barges. MacDonald et al. (2008) estimated higher 

underwater SPLs from the seismic vessel Gilavar of 120 dB at 

approximately 13 mi (21 km) from the source, although the sound level 

was only 150 dB at 85 ft (26 m) from the vessel. Compared to airgun 

pulses, underwater sound from vessels is generally at relatively low 

frequencies.

    The primary sources of sounds from all vessel classes are propeller 

cavitation, propeller singing, and propulsion or other machinery. 

Propeller cavitation is usually the dominant noise source for vessels 

(Ross 1976). Propeller cavitation and singing are produced outside the 

hull, whereas propulsion or other machinery noise originates inside the 

hull. There are additional sounds produced by vessel activity, such as 

pumps, generators, flow noise from water passing over the hull, and 

bubbles breaking in the wake. Icebreakers contribute greater sound 

levels during ice-breaking activities than ships of similar size during 

normal operation in open water (Richardson et al. 1995). This higher 

sound production results from the greater amount of power and propeller 

cavitation required when operating in thick ice. Source levels from 

various vessels would be empirically measured before the start of 

marine surveys.



Anticipated Effects on Habitat



    The primary potential impacts to marine mammals and other marine 

species are associated with elevated sound levels produced by airguns 

and other active acoustic sources. However, other potential impacts to 

the surrounding habitat from physical disturbance are also possible.



Potential Impacts on Prey Species



    With regard to fish as a prey source for cetaceans and pinnipeds, 

fish are known to hear and react to sounds and to use sound to 

communicate (Tavolga et al. 1981) and possibly avoid predators (Wilson 

and Dill 2002). Experiments have shown that fish can sense both the 

strength and direction of sound (Hawkins, 1981). Primary factors 

determining whether a fish can sense a sound signal, and potentially 

react to it, are the frequency of the signal and the strength of the 

signal in relation to the natural background noise level.

    The level of sound at which a fish will react or alter its behavior 

is usually well above the detection level. Fish have been found to 

react to sounds when the sound level increased to about 20 dB above the 

detection level of 120 dB (Ona 1988); however, the response threshold 

can depend on the time of year and the fish's physiological condition 

(Engas et al. 1993). In general, fish react more strongly to pulses of 

sound rather than a continuous signal (Blaxter et al. 1981), and a 

quicker alarm response is elicited when the sound signal intensity 

rises rapidly compared to sound rising more slowly to the same level.

    Investigations of fish behavior in relation to vessel noise (Olsen 

et al. 1983; Ona 1988; Ona and Godo 1990) have shown that fish react 

when the sound from the engines and propeller exceeds a certain level. 

Avoidance reactions have been observed in fish such as cod and herring 

when vessels approached close enough that received sound levels are 110 

dB to 130 dB (Nakken 1992; Olsen 1979; Ona and Godo 1990; Ona and 

Toresen 1988). However, other researchers have found that fish such as 

polar cod, herring, and capeline are often attracted to vessels 

(apparently by the noise) and swim toward the vessel (Rostad et al. 

2006). Typical sound source levels of vessel noise in the audible range 

for fish are 150 dB to 170 dB (Richardson et al. 1995).

    Some mysticetes, including bowhead whales, feed on concentrations 

of zooplankton. Some feeding bowhead whales may occur in the Alaskan 

Beaufort Sea in July and August, and others feed intermittently during 

their westward migration in September and October (Richardson and 

Thomson [eds.] 2002; Lowry et al. 2004). However, by the time most 

bowhead



[[Page 32384]]



whales reach the Chukchi Sea (October), they will likely no longer be 

feeding, or if it occurs it will be very limited. A reaction by 

zooplankton to a seismic impulse would only be relevant to whales if it 

caused concentrations of zooplankton to scatter. Pressure changes of 

sufficient magnitude to cause that type of reaction would probably 

occur only very close to the source. Impacts on zooplankton behavior 

are predicted to be negligible, and that would translate into 

negligible impacts on feeding mysticetes. Thus, the proposed activity 

is not expected to have any habitat-related effects that could cause 

significant or long-term consequences for individual marine mammals or 

their populations.



Proposed Mitigation



    In order to issue an incidental take authorization under Section 

101(a)(5)(D) of the MMPA, NMFS must set forth the permissible methods 

of taking pursuant to such activity, and other means of effecting the 

least practicable adverse impact on such species or stock and its 

habitat, paying particular attention to rookeries, mating grounds, and 

areas of similar significance, and on the availability of such species 

or stock for taking for certain subsistence uses.

    For the proposed Statoil open water marine seismic survey in the 

Chukchi Sea, Statoil worked with NMFS and proposed the following 

mitigation measures to minimize the potential impacts to marine mammals 

in the project vicinity as a result of the marine seismic survey 

activities.

    As part of the application, Statoil submitted to NMFS a Marine 

Mammal Monitoring and Mitigation Program (4MP) for its open water 

seismic survey in the Chukchi Sea during the 2010 open-water season. 

The objectives of the 4MP are:

     to ensure that disturbance to marine mammals and 

subsistence hunts is minimized and all permit stipulations are 

followed,

     to document the effects of the proposed survey activities 

on marine mammals, and

     to collect baseline data on the occurrence and 

distribution of marine mammals in the study area.

    The 4MP may be modified or supplemented based on comments or new 

information received from the public during the public comment period 

or from the peer review panel (see the ``Monitoring Plan Peer Review'' 

section later in this document).



Mitigation Measures Proposed in Statoil's IHA Application



    For the proposed mitigation measures, Statoil listed the following 

protocols to be implemented during its marine seismic survey in the 

Chukchi Sea.

(1) Sound Source Measurements

    As described above, previous measurements of similar airgun arrays 

in the Chukchi Sea were used to model the distances at which received 

levels are likely to fall below 120, 160, 180, and 190 dB re 1 microPa 

(rms) from the planned airgun sources. These modeled distances will be 

used as temporary safety radii until measurements of the airgun sound 

source are conducted. The measurements will be made at the beginning of 

the field season and the measured radii used for the remainder of the 

survey period.

    The objectives of the sound source verification measurements 

planned for 2010 in the Chukchi Sea will be to measure the distances in 

the broadside and endfire directions at which broadband received levels 

reach 190, 180, 170, 160, and 120 dB re 1 microPa (rms) for the energy 

source array combinations that may be used during the survey 

activities. The configurations will include at least the full array and 

the operation of a single mitigation source that will be used during 

power downs. The measurements of energy source array sounds will be 

made by an acoustics contractor at the beginning of the survey and the 

distances to the various radii will be reported as soon as possible 

after recovery of the equipment. The primary radii of concern will be 

the 190 and 180 dB safety radii for pinnipeds and cetaceans, 

respectively, and the 160 dB radii for zone of influence (ZOI). In 

addition to reporting the radii of specific regulatory concern, nominal 

distances to other sound isopleths down to 120 dB (rms) will be 

reported in increments of 10 dB.

    Data will be previewed in the field immediately after download from 

the ocean bottom hydrophone (OBH) instruments. An initial sound source 

analysis will be supplied to NMFS and the airgun operators within 120 

hours of completion of the measurements, if possible. The report will 

indicate the distances to sound levels between 190 dB re 1 microPa 

(rms) and 120 dB re 1 microPa (rms) based on fits of empirical 

transmission loss formulae to data in the endfire and broadside 

directions. The 120-hour report findings will be based on analysis of 

measurements from at least three of the OBH systems. A more detailed 

report including analysis of data from all OBH systems will be issued 

to NMFS as part of the 90-day report following completion of the 

acoustic program.

(2) Safety and Disturbance Zones

    Under current NMFS guidelines, ``safety radii'' for marine mammal 

exposure to impulse sources are customarily defined as the distances 

within which received sound levels are micro180 dB re 1 microPa (rms) 

for cetaceans and micro190 dB re 1 microPa (rms) for pinnipeds. These 

safety criteria are based on an assumption that SPL received at levels 

lower than these will not injure these animals or impair their hearing 

abilities, but that at higher levels might have some such effects. 

Disturbance or behavioral effects to marine mammals from underwater 

sound may occur after exposure to sound at distances greater than the 

safety radii (Richardson et al. 1995).

    Initial safety and disturbance radii for the sound levels produced 

by the survey activities have been estimated from measurements of 

similar seismic arrays used in the Chukchi Sea in previous years. These 

radii will be used for mitigation purposes until results of direct 

measurements are available early during the exploration activities.

    The basis for the estimation of distances to the four received 

sound levels from the proposed 3000 in\3\ airgun array operating at a 

depth of 20 ft (6 m) are the 2006, 2007 and 2008 sound source 

verification (SSV) measurements in the Chukchi Sea of a similar array, 

towed at a similar depth. The measured airgun array had a total 

discharge volume of 3,147 in\3\ and was composed of three identically-

tuned Bolt airgun sub-arrays, totaling 24 airguns (6 clusters of 2 

airguns and 12 single airguns). The proposed 3,000 in\3\ array is also 

composed of three strings with a total of 26 active airguns in 13 

clusters. The difference in discharge volume would lead to an expected 

loss of less than 0.2 dB and is neglected in this assessment. The 

estimated source level for the full 3,000 in\3\ array is 245 dB re 1 

microPA (rms). Without measurement data for the specific site to be 

surveyed, it is reasonable to adopt the maximum distances obtained from 

a similar array during previous measurements in the Chukchi Sea. Table 

1 summarizes the distances to received levels of 190, 180 160, and 120 

dB re 1 microPa (rms) that are adopted for the analysis for the 

proposed survey. Distances for received levels of 120 dB are highly 

variable, in part because the bottom geoacoustic properties will have a 

major effect on received levels at such distances.



[[Page 32385]]



    To estimate the distances to various received levels from the 60 

in\3\ mitigation gun the data from previous measurements of a 30 in\3\ 

gun were used. In general the pressure increase relative to a 30 in\3\ 

gun can be derived by calculating the square root of (60/30), which is 

1.41. This means that the dB levels for the sound pressure levels of a 

60 in\3\ will increase by approximately 3 dB (20Log[1.41]) compared to 

the 30 in\3\ gun. The distances as summarized in Table 1 were derived 

by adding 3 dB to the constant term of the equation RL = 226.6 - 

21.2log(R) - 0.00022R. The estimated source level of this single 60 

in\3\ airgun is 230 dB re 1 microPa (rms).



 Table 1. Estimated distances to received sound levels micro190, 180, 170, 160, and 120 dB re 1 microPa (rms) from the 3,000 in\3\ airgun array and the

    60 in\3\ mitigation gun of the proposed seismic survey. These distances are based on measurements in the Chukchi Sea from a similar airgun array.

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

                                                                                                Distance (m)

      Received Levels (dB re 1 microPa rms)       ------------------------------------------------------------------------------------------------------

                                                                3,000 in\3\ (full airgun array)                      60 in\3\ (mitigation airgun)

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

190                                                                                                     700                                          70

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

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

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

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



    An acoustics contractor will perform the direct measurements of the 

received levels of underwater sound versus distance and direction from 

the energy source arrays using calibrated hydrophones. The acoustic 

data will be analyzed as quickly as reasonably practicable in the field 

and used to verify (and if necessary adjust) the safety distances. The 

field report will be made available to NMFS and the MMOs within 120 hrs 

of completing the measurements. The mitigation measures to be 

implemented at the 190 and 180 dB sound levels will include power downs 

and shut downs as described below.

(3) Power Downs and Shut Downs

    A power-down is the immediate reduction in the number of operating 

energy sources from all firing to some smaller number. A shutdown is 

the immediate cessation of firing of all energy sources. The arrays 

will be immediately powered down whenever a marine mammal is sighted 

approaching close to or within the applicable safety zone of the full 

arrays but is outside or about to enter the applicable safety zone of 

the single mitigation source. If a marine mammal is sighted within the 

applicable safety zone of the single mitigation airgun, the entire 

array will be shut down (i.e., no sources firing).

    Following a power-down or shutdown, operation of the airgun array 

will not resume until the marine mammal has cleared the applicable 

safety zone. The animal will be considered to have cleared the safety 

zone if it:

     Is visually observed to have left the safety zone;

     Has not been seen within the zone for 15 min in the case 

of small odontocetes and pinnipeds; or

     Has not been seen within the zone for 30 min in the case 

of mysticetes.

(4) Ramp Ups

    A ramp up of an airgun array provides a gradual increase in sound 

levels, and involves a stepwise increase in the number and total volume 

of airguns firing until the full volume is achieved.

    The purpose of a ramp up (or ``soft start'') is to ``warn'' 

cetaceans and pinnipeds in the vicinity of the airguns and to provide 

time for them to leave the area and thus avoid any potential injury or 

impairment of their hearing abilities.

    During the proposed seismic survey, the seismic operator will ramp 

up the airgun arrays slowly. Full ramp ups (i.e., from a cold start 

after a shut down, when no airguns have been firing) will begin by 

firing a single airgun in the array. The minimum duration of a shut-

down period, i.e., without air guns firing, which must be followed by a 

ramp up, is typically the amount of time it would take the source 

vessel to cover the 180-dB safety radius. The actual time period 

depends on ship speed and the size of the 180-dB safety radius. That 

period is estimated to be about 15 - 20 minutes based on the modeling 

results described above and a survey speed of 4 knots.

    A full ramp up, after a shut down, will not begin until there has 

been a minimum of 30 min of observation of the safety zone by MMOs to 

assure that no marine mammals are present. The entire safety zone must 

be visible during the 30-minute lead-in to a full ramp up. If the 

entire safety zone is not visible, then ramp up from a cold start 

cannot begin. If a marine mammal(s) is sighted within the safety zone 

during the 30-minute watch prior to ramp up, ramp up will be delayed 

until the marine mammal(s) is sighted outside of the safety zone or the 

animal(s) is not sighted for at least 15 - 30 minutes: 15 minutes for 

small odontocetes and pinnipeds, or 30 minutes for baleen whales and 

large odontocetes.

    During turns and transit between seismic transects, at least one 

airgun will remain operational. The ramp-up procedure still will be 

followed when increasing the source levels from one airgun to the full 

arrays. However, keeping one airgun firing will avoid the prohibition 

of a cold start during darkness or other periods of poor visibility. 

Through use of this approach, seismic operations can resume upon entry 

to a new transect without a full ramp up and the associated 30-minute 

lead-in observations. MMOs will be on duty whenever the airguns are 

firing during daylight, and during the 30-min periods prior to ramp-ups 

as well as during ramp-ups. Daylight will occur for 24 h/day until mid-

August, so until that date MMOs will automatically be observing during 

the 30-minute period preceding a ramp up. Later in the season, MMOs 

will be called out at night to observe prior to and during any ramp up. 

The seismic operator and MMOs will maintain records of the times when 

ramp-ups start, and when the airgun arrays reach full power.



Additional Mitigation Measures Proposed by NMFS



    Besides Statoil's proposed mitigation measures discussed above, 

NMFS proposes the following additional protective measures to address 

some uncertainties regarding the impacts of



[[Page 32386]]



bowhead cow-calf pairs and aggregations of whales from seismic surveys. 

Specifically, NMFS proposes that

     A 160-dB vessel monitoring zone for large whales will be 

established and monitored in the Chukchi Sea during all seismic 

surveys. Whenever an aggregation of bowhead whales or gray whales (12 

or more whales of any age/sex class that appear to be engaged in a 

nonmigratory, significant biological behavior (e.g., feeding, 

socializing)) are observed during an aerial or vessel monitoring 

program within the 160-dB safety zone around the seismic activity, the 

seismic operation will not commence or will shut down, until two 

consecutive surveys (aerial or vessel) indicate they are no longer 

present within the 160-dB safety zone of seismic-surveying operations.

     Survey information, especially information about bowhead 

whale cow/calf pairs or feeding bowhead or gray whales, shall be 

provided to NMFS as required in MMPA authorizations, and will form the 

basis for NMFS determining whether additional mitigation measures, if 

any, will be required over a given time period.

    Furthermore, NMFS proposes the following measures be included in 

the IHA, if issued, in order to ensure the least practicable impact on 

the affected species or stocks:

    (1) All vessels should reduce speed when within 300 yards (274 m) 

of whales, and those vessels capable of steering around such groups 

should do so. Vessels may not be operated in such a way as to separate 

members of a group of whales from other members of the group;

    (2) Avoid multiple changes in direction and speed when within 300 

yards (274 m) of whales; and

    (3) When weather conditions require, such as when visibility drops, 

support vessels must adjust speed accordingly to avoid the likelihood 

of injury to whales.



Mitigation Conclusions



    NMFS has carefully evaluated the applicant's proposed mitigation 

measures and considered a range of other measures in the context of 

ensuring that NMFS prescribes the means of effecting the least 

practicable impact on the affected marine mammal species and stocks and 

their habitat. Our evaluation of potential measures included 

consideration of the following factors in relation to one another:

     the manner in which, and the degree to which, the 

successful implementation of the measure is expected to minimize 

adverse impacts to marine mammals;

     the proven or likely efficacy of the specific measure to 

minimize adverse impacts as planned; and

     the practicability of the measure for applicant 

implementation.

    Based on our evaluation of the applicant's proposed measures, as 

well as other measures considered by NMFS, NMFS has preliminarily 

determined that the proposed mitigation measures provide the means of 

effecting the least practicable impact on marine mammal species or 

stocks and their habitat, paying particular attention to rookeries, 

mating grounds, and areas of similar significance.



Proposed Monitoring and Reporting



    In order to issue an ITA for an activity, Section 101(a)(5)(D) of 

the MMPA states that NMFS must set forth ``requirements pertaining to 

the monitoring and reporting of such taking''. The MMPA implementing 

regulations at 50 CFR 216.104 (a)(13) indicate that requests for ITAs 

must include the suggested means of accomplishing the necessary 

monitoring and reporting that will result in increased knowledge of the 

species and of the level of taking or impacts on populations of marine 

mammals that are expected to be present in the proposed action area.



Monitoring Measures Proposed in Statoil's IHA Application



    The monitoring plan proposed by Statoil can be found in the 4MP. 

The plan may be modified or supplemented based on comments or new 

information received from the public during the public comment period 

or from the peer review panel (see the ``Monitoring Plan Peer Review'' 

section later in this document). A summary of the primary components of 

the plan follows.

(1) Vessel-Based MMOs

    Vessel-based monitoring for marine mammals will be done by trained 

MMOs throughout the period of marine survey activities. MMOs will 

monitor the occurrence and behavior of marine mammals near the survey 

vessel during all daylight periods during operation and during most 

daylight periods when airgun operations are not occurring. MMO duties 

will include watching for and identifying marine mammals, recording 

their numbers, distances, and reactions to the survey operations, and 

documenting ``take by harassment'' as defined by NMFS.

    A sufficient number of MMOs will be required onboard the survey 

vessel to meet the following criteria: (1) 100% monitoring coverage 

during all periods of survey operations in daylight; (2) maximum of 4 

consecutive hours on watch per MMO; and (3) maximum of 12 hours of 

watch time per day per MMO.

    MMO teams will consist of Inupiat observers and experienced field 

biologists. An experienced field crew leader will supervise the MMO 

team onboard the survey vessel. The total number of MMOs may decrease 

later in the season as the duration of daylight decreases.

    Statoil anticipates one crew change to occur approximately half-way 

through the season. During crew rotations detailed hand-over notes will 

be provided to the incoming crew leader by the outgoing leader. Other 

communications such as email, fax, and/or phone communication between 

the current and oncoming crew leaders during each rotation will also 

occur when possible. In the event of an unexpected crew change Statoil 

will facilitate such communications to insure monitoring consistency 

among shifts.

    Crew leaders and most other biologists serving as observers in 2010 

will be individuals with experience as observers during one or more of 

the 1996-2009 seismic or shallow hazards monitoring projects in Alaska, 

the Canadian Beaufort, or other offshore areas in recent years.

    Biologist-observers will have previous marine mammal observation 

experience, and field crew leaders will be highly experienced with 

previous vessel-based marine mammal monitoring and mitigation projects. 

Resumes for those individuals will be provided to NMFS for review and 

acceptance of their qualifications. Inupiat observers will be 

experienced in the region, familiar with the marine mammals of the 

area, and complete a NMFS approved observer training course designed to 

familiarize individuals with monitoring and data collection procedures. 

A marine mammal observers' handbook, adapted for the specifics of the 

planned survey program, will be prepared and distributed beforehand to 

all MMOs.

    Most observers, including Inupiat observers, will also complete a 

two or three-day training and refresher session on marine mammal 

monitoring, to be conducted shortly before the anticipated start of the 

2010 open-water season. Any exceptions will have or receive equivalent 

experience or training. The training session(s) will be conducted by 

qualified marine mammalogists with extensive crew-leader experience 

during previous vessel-based seismic monitoring programs.

    Primary objectives of the training include:



[[Page 32387]]



     review of the marine mammal monitoring plan for this 

project, including any amendments specified by NMFS in the IHA (if 

issued), by USFWS and by MMS, or by other agreements in which Statoil 

may elect to participate;

     review of marine mammal sighting, identification, and 

distance estimation methods;

     review of operation of specialized equipment (reticle 

binoculars, night vision devices, and GPS system);

     review of, and classroom practice with, data recording and 

data entry systems, including procedures for recording data on marine 

mammal sightings, monitoring operations, environmental conditions, and 

entry error control. These procedures will be implemented through use 

of a customized computer database and laptop computers;

     review of the specific tasks of the Inupiat Communicator.

    The MMOs will watch for marine mammals from the best available 

vantage point on the survey vessels, typically the bridge. The MMOs 

will scan systematically with the unaided eye and 7 50 reticle 

binoculars, supplemented during good visibility conditions with Fujinon 

25x150 ``Big-eye'' binoculars mounted on a bride wing or flying bridge 

(seismic vessel only), and night-vision equipment when needed (see 

below). Personnel on the bridge will assist the marine mammal 

observer(s) in watching for marine mammals. Data from the infrared 

radar will be monitored in order to investigate if this could improve 

the detection and record keeping of mammals, especially during periods 

of low visibility.

    Information to be recorded by marine mammal observers will include 

the same types of information that were recorded during recent 

monitoring programs associated with industry activity in the Arctic 

(e.g., Ireland et al. 2009). When a mammal sighting is made, the 

following information about the sighting will be recorded:

    (A) Species, group size, age/size/sex categories (if determinable), 

behavior when first sighted and after initial sighting, heading (if 

consistent), bearing and distance from the MMO, apparent reaction to 

activities (e.g., none, avoidance, approach, paralleling, etc.), 

closest point of approach, and behavioral pace;

    (B) Time, location, speed, activity of the vessel, sea state, ice 

cover, visibility, and sun glare; and

    (C) The positions of other vessel(s) in the vicinity of the MMO 

location.

    The ship's position, speed of support vessels, and water 

temperature, water depth, sea state, ice cover, visibility, and sun 

glare will also be recorded at the start and end of each observation 

watch, every 30 minutes during a watch, and whenever there is a change 

in any of those variables.

    Distances to nearby marine mammals will be estimated with 

binoculars (Fujinon 7 x 50 binoculars) containing a reticle to measure 

the vertical angle of the line of sight to the animal relative to the 

horizon. MMOs may use a laser rangefinder to test and improve their 

abilities for visually estimating distances to objects in the water. 

However, previous experience showed that a Class 1 eye-safe device was 

not able to measure distances to seals more than about 230 ft (70 m) 

away. The device was very useful in improving the distance estimation 

abilities of the observers at distances up to about 1,968 ft (600 m)-

the maximum range at which the device could measure distances to highly 

reflective objects such as other vessels. Humans observing objects of 

more-or-less known size via a standard observation protocol, in this 

case from a standard height above water, quickly become able to 

estimate distances within about =20% when given immediate feedback 

about actual distances during training.



Monitoring At Night and In Poor Visibility



    Night-vision equipment (Generation 3 binocular image intensifiers, 

or equivalent units) will be available for use when/if needed. Past 

experience with night-vision devices (NVDs) in the Beaufort Sea and 

elsewhere has indicated that NVDs are not nearly as effective as visual 

observation during daylight hours (e.g., Harris et al. 1997, 1998; 

Moulton and Lawson 2002).

    A prototype infrared radar will be mounted on the source vessel in 

order to try to improve the visual observations during times of poor 

visibility. The infrared radar detects thermal contrasts and its 

ability to sense these differences is not dependent on daylight. It may 

therefore improve the ability to detect marine mammals during 

nighttime. The ability of the IR radar to detect marine mammals is not 

yet proven and the intent is to collect data that can help determine if 

it can be used as an effective monitoring tool in the future. However, 

if during the course of testing, a reliable detection of a marine 

mammal within a safety zone requiring a mitigation action is made using 

the radar system, the necessary actions will be taken by the MMOs. That 

is, even if the system is not entirely proven, reliable results made 

during testing that may provide protection to marine mammals will not 

be ignored.

(2) Acoustic Monitoring



Sound Source Measurements



    As described above, previous measurements of airguns in the Chukchi 

Sea were used to estimate the distances at which received levels are 

likely to fall below 120, 160, 180, and 190 dB re 1 microPa (rms) from 

the planned airgun sources. These modeled distances will be used as 

temporary safety radii until measurements of the airgun sound source 

are conducted. The measurements will be made at the beginning of the 

field season and the measured radii used for the remainder of the 

survey period. An acoustics contractor with experience in the Arctic 

conducting similar measurements in recent years will use their 

equipment to record and analyze the underwater sounds and write the 

summary reports as described below.

    The objectives of the sound source verification measurements 

planned for 2010 in the Chukchi Sea will be (1) to measure the 

distances in the broadside and endfire directions at which broadband 

received levels reach 190, 180, 170, 160, and 120 dB re 1 microPa (rms) 

for the energy source array combinations that may be used during the 

survey activities. The configurations will include at least the full 

array and the operation of a single mitigation source that will be used 

during power downs. The measurements of energy source array sounds will 

be made by an acoustics contractor at the beginning of the survey and 

the distances to the various radii will be reported as soon as possible 

after recovery of the equipment. The primary radii of concern will be 

the 190 and 180 dB safety radii for pinnipeds and cetaceans, 

respectively, and the 160 dB disturbance radii. In addition to 

reporting the radii of specific regulatory concern, nominal distances 

to other sound isopleths down to 120 dB re 1 microPa (rms) will be 

reported in increments of 10 dB.

    Data will be previewed in the field immediately after download from 

the hydrophone instruments. An initial sound source analysis will be 

supplied to NMFS and the airgun operators within 120 hours of 

completion of the measurements, if possible. The report will indicate 

the distances to sound levels based on fits of empirical transmission 

loss formulae to data in the endfire and broadside directions. A more 

detailed report will be issued to NMFS as part of the 90-day report 

following completion of the acoustic program.



[[Page 32388]]



2010 Shared Science Program



    Statoil, Shell, and ConocoPhillips (CPAI) are jointly funding an 

extensive science program in the Chukchi Sea. This program will be 

carried out by Olgoonik-Fairweather LLC (OFJV) with the vessels 

Norseman II and Westward Wind during the 2010 open water season. The 

science program is not part of the Statoil seismic program, but worth 

mentioning in this context due to the acoustic monitoring array 

deployed within the seismic survey area as shown in Figures 1 and 2 of 

Statoil's IHA application. The science program components include:

     Acoustics Monitoring

     Fisheries Ecology

     Benthic Ecology

     Plankton Ecology

     Mammals

     Seabirds

     Physical Oceanography

    The 2010 program continues the acoustic monitoring programs of 

2006-2009 with a total of 44 acoustic recorders distributed both 

broadly across the Chukchi lease area and nearshore environment and 

intensively on the Statoil, Burger (Shell), and Klondike (CPAI) lease 

holdings. The recorders will be deployed in late July or early August 

and will be retrieved in early to mid-October, depending on ice 

conditions. The recorders will be the Advanced Multi-Channel Acoustic 

Recorder (AMAR) and the Autonomous Underwater Recorder for Acoustic 

Listening (AURAL) model acoustic buoys set to record at 16 kHz sample 

rate. These are the same recorder models and same sample rates that 

have been used for this program from 2006 - 2009. The broad area arrays 

are designed to capture both general background soundscape data, 

seismic survey sounds and marine mammal call data across the lease 

area. From these recordings we have been able to gain insight into 

large-scale distributions of marine mammals, identification of marine 

mammal species present, movement and migration patterns, and general 

abundance data.

    The site specific focused arrays are designed to also support 

localization of marine mammal calls on and around the leaseholdings. In 

the case of the Statoil prospect, where Statoil intends to conduct 

seismic data acquisition in 2010, localized calls will enable 

investigators to understand responses of marine mammals to survey 

operations both in terms of distribution around the operation and 

behavior (i.e. calling behavior). The site specific array will consist 

of 7 AMAR recorders deployed in a hexagonal configuration as shown in 

Figure 2 of Statoil's 4MP, with inter-recorder spacing of 8 km (12.9 

mi). These recorders are the same types that were used successfully in 

the 2009 site-specific acoustic monitoring program on Shell and CPAI 

prospects. The recorded sample resolution is 24-bits and sample 

frequency is 16 kHz, which is sufficient to capture part or all of the 

sounds produced by the marine mammal species known to be present, with 

the exception of harbor porpoise. The recorders will be synchronized to 

support localization of calling bowhead whales. Other species' calls 

are typically detected from distances less than the 8 km recorder 

separation. Consequently the multi-sensor triangulation method, that is 

used for bowheads calls, will not be used to determine calling 

locations of other species; however, detection of other species' calls 

indicates the animal position within a circular region of radius equal 

to the maximum detection distances of a few kilometers.



Monitoring Plan Peer Review



    The MMPA requires that monitoring plans be independently peer 

reviewed ``where the proposed activity may affect the availability of a 

species or stock for taking for subsistence uses'' (16 U.S.C. 

1371(a)(5)(D)(ii)(III)). Regarding this requirement, NMFS' implementing 

regulations state, ``Upon receipt of a complete monitoring plan, and at 

its discretion, [NMFS] will either submit the plan to members of a peer 

review panel for review or within 60 days of receipt of the proposed 

monitoring plan, schedule a workshop to review the plan'' (50 CFR 

216.108(d)).

    NMFS convened an independent peer review panel to review Statoil's 

mitigation and monitoring plan in its IHA application for taking marine 

mammals incidental to the proposed marine seismic survey in the Chukchi 

Sea, during 2010. The panel met and reviewed the plan in late March 

2010, and provided comments to NMFS in late April 2010. NMFS will 

consider all recommendations made by the panel, incorporate appropriate 

changes into the monitoring requirements of the IHA (if issued) and 

publish the panel's findings and recommendations in the final IHA 

notice of issuance or denial document.



Reporting Measures



(1) SSV Report

    A report on the preliminary results of the acoustic verification 

measurements, including as a minimum the measured 190-, 180-, 160-, and 

120-dB re 1 microPa (rms) radii of the source vessel(s) and the support 

vessels, will be submitted within 120 hr after collection and analysis 

of those measurements at the start of the field season. This report 

will specify the distances of the safety zones that were adopted for 

the marine survey activities.

(2) Field Reports

    Statoil states that throughout the survey program, the observers 

will prepare a report each day or at such other interval as the IHA (if 

issued), or Statoil may require summarizing the recent results of the 

monitoring program. The field reports will summarize the species and 

numbers of marine mammals sighted. These reports will be provided to 

NMFS and to the survey operators.

(3) Technical Reports

    The results of Statoil's 2010 open water marine survey monitoring 

program (i.e., vessel-based, aerial, and acoustic), including estimates 

of ``take'' by harassment, will be presented in the ``90-day'' and 

Final Technical reports. Statoil proposes that the Technical Reports 

will include:

    (a) summaries of monitoring effort (e.g., total hours, total 

distances, and marine mammal distribution through the study period, 

accounting for sea state and other factors affecting visibility and 

detectability of marine mammals);

    (b) analyses of the effects of various factors influencing 

detectability of marine mammals (e.g., sea state, number of observers, 

and fog/glare);

    (c) species composition, occurrence, and distribution of marine 

mammal sightings, including date, water depth, numbers, age/size/gender 

categories (if determinable), group sizes, and ice cover;

    (d) analyses of the effects of survey operations;

     sighting rates of marine mammals during periods with and 

without airgun activities (and other variables that could affect 

detectability), such as:

     initial sighting distances versus airgun activity state;

     closest point of approach versus airgun activity state;

     observed behaviors and types of movements versus airgun 

activity state;

     numbers of sightings/individuals seen versus airgun 

activity state;

     distribution around the survey vessel versus airgun 

activity state; and

     estimates of take by harassment.

    This information will be reported for both the vessel-based and 

aerial monitoring.

(4) Comprehensive Report

    Following the 2010 open-water season a comprehensive report 

describing the



[[Page 32389]]



vessel-based, aerial, and acoustic monitoring programs will be 

prepared. The comprehensive report will describe the methods, results, 

conclusions and limitations of each of the individual data sets in 

detail. The report will also integrate (to the extent possible) the 

studies into a broad based assessment of industry activities, and other 

activities that occur in the Beaufort and/or Chukchi seas, and their 

impacts on marine mammals during 2010. The report will help to 

establish long-term data sets that can assist with the evaluation of 

changes in the Chukchi and Beaufort sea ecosystems. The report will 

attempt to provide a regional synthesis of available data on industry 

activity in offshore areas of northern Alaska that may influence marine 

mammal density, distribution and behavior.

(5) Notification of Injured or Dead Marine Mammals

    In addition to the reporting measures proposed by Statoil, NMFS 

will require that Statoil notify NMFS' Office of Protected Resources 

and NMFS' Stranding Network within 48 hours of sighting an injured or 

dead marine mammal in the vicinity of marine survey operations. Statoil 

shall provide NMFS with the species or description of the animal(s), 

the condition of the animal(s) (including carcass condition if the 

animal is dead), location, time of first discovery, observed behaviors 

(if alive), and photo or video (if available).

    In the event that an injured or dead marine mammal is found by 

Statoil that is not in the vicinity of the proposed open water marine 

survey program, Statoil will report the same information as listed 

above as soon as operationally feasible to NMFS.



Estimated Take by Incidental 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]. Only take by Level B behavioral 

harassment is anticipated as a result of the proposed open water marine 

survey program. Anticipated impacts to marine mammals are associated 

with noise propagation from the seismic airgun(s) used in the seismic 

survey.

    The full suite of potential impacts to marine mammals was described 

in detail in the ``Potential Effects of the Specified Activity on 

Marine Mammals'' section found earlier in this document. The potential 

effects of sound from the proposed open water marine survey programs 

might include one or more of the following: tolerance; masking of 

natural sounds; behavioral disturbance; non-auditory physical effects; 

and, at least in theory, temporary or permanent hearing impairment 

(Richardson et al. 1995). As discussed earlier in this document, the 

most common impact will likely be from behavioral disturbance, 

including avoidance of the ensonified area or changes in speed, 

direction, and/or diving profile of the animal. For reasons discussed 

previously in this document, hearing impairment (TTS and PTS) are 

highly unlikely to occur based on the proposed mitigation and 

monitoring measures that would preclude marine mammals being exposed to 

noise levels high enough to cause hearing impairment.

    For impulse sounds, such as those produced by airgun(s) used in the 

seismic survey, NMFS uses the 160 dB re 1 microPa (rms) isopleth to 

indicate the onset of Level B harassment. Statoil provided calculations 

for the 160-dB isopleths produced by these active acoustic sources and 

then used those isopleths to estimate takes by harassment. NMFS used 

the calculations to make the necessary MMPA preliminary findings. 

Statoil provided a full description of the methodology used to estimate 

takes by harassment in its IHA application (see ADDRESSES), which is 

also provided in the following sections.

    Statoil has requested an authorization to take 13 marine mammal 

species by Level B harassment. These 13 marine mammal species are: 

beluga whale (Delphinapterus leucas), narwhal (Monodon monoceros), 

killer whale (Orcinus orca), harbor porpoise (Phocoena phocoena), 

bowhead whale (Balaena mysticetus), gray whale (Eschrichtius robustus), 

humpback whale (Megaptera novaeangliae), minke whale (Balaenoptera 

acutorostrata), fin whale (B. physalus), bearded seal (Erignathus 

barbatus), ringed seal (Phoca hispida), spotted seal (P. largha), and 

ribbon seal (Histriophoca fasciata). However, NMFS consider that 

narwhals are not likely to occur in the proposed survey area during the 

time of the proposed marine seismic survey. Therefore, NMFS considers 

that only the other 12 marine mammal species could be affected by Level 

B behavioral harassment as a result of the proposed marine surveys.



Basis for Estimating ``Take by Harassment''



    As stated previously, it is current NMFS policy to estimate take by 

Level B harassment for impulse sounds at a received level of 160 dB re 

1microPa (rms). However, not all animals react to sounds at this low 

level, and many will not show strong reactions (and in some cases any 

reaction) until sounds are much stronger. Southall et al. (2007) 

provide a severity scale for ranking observed behavioral responses of 

both free-ranging marine mammals and laboratory subjects to various 

types of anthropogenic sound (see Table 4 in Southall et al. (2007)). 

Tables 7, 9, and 11 in Southall et al. (2007) outline the numbers of 

low-frequency cetaceans, mid-frequency cetaceans, and pinnipeds in 

water, respectively, reported as having behavioral responses to multi-

pulses in 10-dB received level increments. These tables illustrate that 

the more severe reactions did not occur until sounds were much higher 

than 160 dB re 1microPa (rms).

    As described earlier in the document, the proposed open water 

marine seismic survey would use two airgun arrays with a total 

discharge volume of 3,000 in\3\. The modeled 160 dB zone of influence 

reaches to 13 km from the airgun source. The estimated number of 

animals potentially harassed was calculated by multiplying the expected 

densities (in number/km\2\) by the anticipated area ensonified by 

levels of micro160 dB re 1microPa. Estimates of the number of animals 

potentially impacted were conducted separately for the 3D survey area 

and the 2D survey lines. For the 3D survey area, the anticipated area 

ensonified by sound levels of micro160 dB was calculated as an area 

encompassing a 8.1 mi (13 km) radius extending from each point of the 

survey area perimeter (hereafter called the 160 dB exposed survey 

area). This approach was taken because closely spaced survey lines and 

large cross-track distances of the micro160 dB radii result in repeated 

exposure of the same area of water. Excessive amounts of repeated 

exposure leads to an overestimation of the number of animals 

potentially exposed. For the 2D survey lines the area ensonified by 

sound levels of micro160 dB was calculated as the total line kilometers 

multiplied by 2 times the 8.1 mi (13 km) micro160 dB safety radius. The 

following subsections describe in more detail the data and methods used 

in deriving the estimated number of animals potentially ``taken by 

harassment'' during the proposed survey. It provides information on the



[[Page 32390]]



expected marine mammal densities, estimated distances to received 

levels of 190, 180, 160, and 120 dB re 1microPa and the calculation of 

anticipated areas ensonified by levels of micro160 dB.

    It is important to understand that not all published results from 

visual observations have applied correction factors that account for 

detectability and availability bias. Detectability bias, quantified in 

part by f(0), is associated with diminishing sightability with 

increasing lateral distance from the survey trackline. Availability 

bias [g(0)] refers to the fact that not all animals are at the surface 

and that there is therefore <100% probability of sighting an animal 

that is present along the survey trackline. Some sources below included 

correction factors in the reported densities (e.g., ringed seals in 

Bengtson et al. 2005) and the best available correction factors were 

applied to reported results when they had not already been included 

(e.g., Moore et al. 2000b).

(1) Cetaceans

    Eight species of cetaceans are known to occur in the Chukchi Sea 

area of the proposed Statoil project. Only four of these (bowhead, 

beluga, and gray whales, and harbor porpoise) are likely to be 

encountered during the proposed survey activities. Three of the eight 

species (bowhead, fin, and humpback whales) are listed as endangered 

under the ESA. Of these, only the bowhead is likely to be found within 

the survey area.

    Beluga Whales - Summer densities of beluga in offshore waters are 

expected to be low. Aerial surveys have recorded few belugas in the 

offshore Chukchi Sea during the summer months (Moore et al. 2000b). 

Aerial surveys of the Chukchi Sea in 2008-2009 flown by the NMML as 

part of the Chukchi Offshore Monitoring in Drilling Area project 

(COMIDA) have only reported 5 beluga sightings during >8,700 mi 

(>14,000 km) of on-transect effort, only 2 of which were offshore 

(COMIDA 2009). Additionally, only one beluga sighting was recorded 

during >37,904 mi (>61,000 km) of visual effort during good visibility 

conditions from industry vessels operating in the Chukchi Sea in 

JulymicroAugust of 2006micro2008 (Haley et al. 2009b). If belugas are 

present during the summer, they are more likely to occur in or near the 

ice edge or close to shore during their northward migration. Expected 

densities were calculated from data in Moore et al. (2000b). Data from 

Moore et al. (2000b: Figure 6 and Table 6) used as the average open-

water density estimate included two on-transect beluga sightings during 

6,639 mi (10,684 km) of on-transect effort in the Chukchi Sea during 

summer. A mean group size of 7.1 (CV=1.7) was calculated from 10 

Chukchi Sea summer sightings present in the BWASP database. A f(0) 

value of 2.841 and g(0) value of 0.58 from Harwood et al. (1996) were 

also used in the calculation. The CV associated with group size was 

used to select an inflation factor of 2 to estimate the maximum density 

that may occur in both open-water and ice-margin habitats. Specific 

data on the relative abundance of beluga in open-water versus ice-

margin habitat during the summer in the Chukchi Sea is not available. 

However, Moore et al. (2000b) reported higher than expected beluga 

sighting rates in open-water during fall surveys in the Beaufort and 

Chukchi Seas. This would suggest that densities near ice may actually 

be lower than open water, but belugas are commonly associated with ice, 

so an inflation factor of only 2 (instead of 4) was used to estimate 

the average ice-margin density from the open-water density. Based on 

the very low densities observed from vessels operating in the Chukchi 

Sea during non-seismic periods and locations in JulymicroAugust of 

2006-2008 (0.0001/km\2\; Haley et al. 2009b), the densities shown in 

Table 1 are likely biased high.

    In the fall, beluga whale densities in the Chukchi Sea are expected 

to be somewhat higher than in the summer because individuals of the 

eastern Chukchi Sea stock and the Beaufort Sea stock will be migrating 

south to their wintering grounds in the Bering Sea (Angliss and Allen 

2009). Consistent with this, the number of on-effort beluga sightings 

reported during COMIDA flights in September-October of 2008-2009 was 

over 3 times more than during July-August with a very similar amount of 

on-transect effort (COMIDA 2009). However, there were no beluga 

sightings reported during >11,185 mi (>18,000 km) of vessel based 

effort in good visibility conditions during 2006-2008 industry 

operations in the Chukchi Sea. Densities derived from survey results in 

the northern Chukchi Sea in Moore et al. (2000b) were used as the 

average density for open-water and ice-margin fall season estimates 

(see Table 2). Data from Moore et al. (2000b: Table 8) used in the 

average open-water density estimate included 123 beluga sightings and 

27,559 mi (44,352 km) of on-transect effort in water depths 118-164 ft 

(36-50 m). A mean group size of 2.39 (CV=0.92) came from the average 

group size of 82 Chukchi Sea fall sightings in waters 115-164 ft (35-50 

m) deep present in the BWASP database. A f(0) value of 2.841 and g(0) 

value of 0.58 from Harwood et al. (1996) were used in the calculation. 

The CV associated with group size was used to select an inflation 

factor of 2 to estimate the maximum density that may occur in both 

open-water and ice-margin habitats. Moore et al. (2000b) reported 

higher than expected beluga sighting rates in open-water during fall 

surveys in the Beaufort and Chukchi seas, so an inflation value of only 

2 was used to estimate the average ice-margin density from the open-

water density. There were no beluga sightings from vessels operating in 

the Chukchi Sea during non-seismic periods in September-October of 

2006-2008 (Haley et al. 2009b).



   Table 1. Expected densities of cetaceans and seals in areas of the Chukchi Sea, Alaska, during the planned

                          summer (July - August) period of the seismic survey program.

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

                                                       Nearshore  Average Density    Ice Margin  Average Density

                       Species                              (/km\2\)            (/ km\2\)

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

Beluga whale                                                               0.0033                        0.0162

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

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



[[Page 32391]]



 

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

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

-----------------------------------------------------------------------------------=============================

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





 Table 2. Expected densities of cetaceans and seals in areas of the Chukchi Sea, Alaska, during the planned fall

                           (September - October) period of the seismic survey program.

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

                                                       Nearshore  Average Density    Ice Margin  Average Density

                       Species                              (/km\2\)            (/ km\2\)

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

Beluga whale                                                               0.0162                        0.0324

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

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

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

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

-----------------------------------------------------------------------------------=============================

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



    Bowhead Whales - By July, most bowhead whales are northeast of the 

Chukchi Sea, within or migrating toward their summer feeding grounds in 

the eastern Beaufort Sea. No bowheads were reported during 6,639 mi 

(10,684 km) of on-transect effort in the Chukchi Sea by Moore et al. 

(2000b). Aerial surveys in 2008-2009 by the NMML as part of the COMIDA 

project reported four sightings during >8,699 mi (>14,000 km) of on-

transect effort. Two of the four sightings were offshore, both of which 

occurred near the end of August. Bowhead whales were also rarely 

reported in July-August of 2006-2008 during aerial surveys of the 

Chukchi Sea coast (Thomas et al. 2009). This is consistent with 

movements of tagged whales (see ADFG 2009; Quakenbush 2009), all of 

which moved through the Chukchi Sea by early May 2009, and tended to 

travel relatively close to shore, especially in the northern Chukchi 

Sea.

    The estimate of bowhead whale density in the Chukchi Sea was 

calculated by assuming that there was one bowhead sighting during the 

6,639 mi (10,684 km) survey effort in the Chukchi Sea during the 

summer, although no bowheads were actually observed (Moore et al. 

2000b). The more recent COMIDA data were not used because the NMML has 

not released a final report summarizing the data. Only two sightings 

are present in the BWASP database during July and August in the Chukchi 

Sea, both of which were of individual whales. The mean group size from 

combined July-August sightings in the BWASP, COMIDA, and 2006-2008 

industry database is 1.33 (CV=0.58). This value, along with a f(0) 

value of 2 and a g(0) value of 0.07, both from Thomas et al. (2002) 

were used to estimate a summer density of bowhead whales. The CV of 

group size and standard errors reported in Thomas et al. (2002) for 

f(0) and g(0) correction factors suggest that an inflation factor of 2 

is appropriate for deriving a maximum density from the average density. 

Bowheads are not expected to be encountered in higher densities near 

ice in the summer (Moore et al. 2000b), so the same density estimates 

are used for open-water and ice-margin habitats. Densities from vessel 

based surveys in the Chukchi Sea during non-seismic periods and 

locations in July-August of 2006-2008 (Haley et al. 2009b) ranged from 

0.0001/km\2\ to 0.0005/km\2\ with a



[[Page 32392]]



maximum 95 percent confidence interval (CI) of 0.0019 km\2\. This 

suggests that the densities used in the calculations and shown in Table 

1 might be somewhat higher than expected to be observed from vessels 

near the area of planned operations.

    During the fall, bowhead whales migrate west and south from their 

summer feeding grounds in the Beaufort Sea and Amundsen Gulf to their 

wintering grounds in the Bering Sea. During this fall migration 

bowheads are more likely to be encountered in the Chukchi Sea. Moore et 

al. (2000b: Table 8) reported 34 bowhead sightings during 27,560 mi 

(44,354 km) of on-transect survey effort in the Chukchi Sea during 

September-October. Thomas et al. (2009) also reported increased 

sightings on coastal surveys of the Chukchi Sea during September and 

October of 2006-2008. Aerial surveys in 2008-2009 (COMIDA 2009) 

reported 20 bowhead sightings during 8,803 mi (14,167 km) of on-

transect effort, eight of which were offshore. GPS tagging of bowheads 

show that migration routes through the Chukchi Sea are more variable 

than through the Beaufort Sea (ADFG 2009; Quakenbush 2009). Some of the 

routes taken by bowheads remain well north or south of the planned 

survey activities while others have passed near to or through the area. 

Kernel densities estimated from GPS locations of whales suggest that 

bowheads do not spend much time (e.g., feeding or resting) in the 

north-central Chukchi Sea near the area of planned activities (ADFG 

2009). The mean group size from September-October Chukchi Sea bowhead 

sightings in the BWASP database is 1.59 (CV=1.08). This is slightly 

below the mean group size of 1.85 from all the preliminary COMIDA 

sightings during the same months, but above the value of 1.13 from only 

on-effort COMIDA sightings (COMIDA 2009). The same f(0) and g(0) values 

that were used for the summer estimates above were used for the fall 

estimates. As with the summer estimates, an inflation factor of 2 was 

used to estimate the maximum density from the average density in both 

habitat types. Moore et al. (2000b) found that bowheads were detected 

more often than expected in association with ice in the Chukchi Sea in 

September-October, so a density of twice the average open-water density 

was used as the average ice-margin density. Densities from vessel based 

surveys in the Chukchi Sea during non-seismic periods and locations in 

SeptembermicroOctober of 2006-2008 (Haley et al. 2009b) ranged from 

0.0001/km\2\ to 0.0050/km\2\ with a maximum 95 percent CI of 0.0480 

km\2\. This suggests the densities used in the calculations and shown 

in Table 2 are somewhat higher than are likely to be observed from 

vessels near the area of planned operations.

    Gray Whales - The average open-water summer density was calculated 

from effort and sightings in Moore et al. (2000b: Table 6) for water 

depths 118-164 ft (36-50 m) including 4 sightings during 3,901 mi 

(6,278 km) of on-transect effort. An average group size of 3.11 

(CV=0.97) was calculated from all July-August Chukchi Sea gray whale 

sightings in the BWASP database and used in the summer density 

estimate. This value was higher than the average group size in the 

preliminary COMIDA data (1.71; COMIDA 2009) and from coastal aerial 

surveys in 2006-2008 (1.27; Thomas et al. 2009). Correction factors 

f(0) = 2.49 (Forney and Barlow 1998) and g(0) = 0.30 (Forney and Barlow 

1998; Mallonee 1991) were also used in the density calculation. Since 

the group size used in the average density estimate was relatively high 

compared to other data sources and the CV was near to one, an inflation 

factor of 2 was used to estimate the maximum densities from average 

densities in both habitat types. Gray whales are not commonly 

associated with sea ice, but may occur close to sea ice, so the 

densities for open-water habitat were also used for ice-margin habitat. 

Densities from vessel based surveys in the Chukchi Sea during non-

seismic periods and locations in July-August of 2006-2008 (Haley et al. 

2009b) ranged from 0.0009/km\2\ to 0.0034/km\2\ with a maximum 95 

percent CI of 0.0146 km\2\. This suggests that the densities used in 

the calculations and shown in Table 1 are somewhat higher than are 

expected to be observed from vessels near the area of planned 

operations.

    Gray whale densities are expected to be much higher in the summer 

months than during the fall when most whales start their southbound 

migration. Moore et al. (2000b) found that the distribution of gray 

whales was more widely dispersed through the northern Chukchi Sea and 

limited to nearshore areas where most whales were observed in water 

less than 115 ft (35 m) deep. With similar amounts of on-transect 

effort between summer and fall aerial surveys in 2008-2009, gray whale 

sightings were three times higher in July-August than in September-

October, and five times higher taking into account all effort and 

sightings (COMIDA 2009). Thomas et al. (2009) also reported decreased 

sighting rates of gray whales in the fall.

    The on-transect effort and associated gray whale sightings (27 

sightings during 44,352 km of on-transect effort) in water depth of 

118-164 ft (36-50 m) during autumn (Moore et al. 2000b; 12) was used as 

the average density estimate for the Chukchi Sea during the fall 

period. A group size value of 2.49 (CV=1.37) calculated from the BWASP 

database was used in the density calculation, along with the same f(0) 

and g(0) values described above. The group size value of 2.49 was again 

higher than the average group size calculated from preliminary COMIDA 

data (1.24; COMIDA 2009) and as reported from coastal aerial surveys in 

2006-2008 (1.12; Thomas et al. 2009). Densities from vessel based 

surveys in the Chukchi Sea during non-seismic periods and locations in 

September-October of 2006-2008 (Haley et al. 2009b) ranged from 0.0011/

km\2\ to 0.0024/km\2\ with a maximum 95 percent CI of 0.0183 km\2\. 

This suggests the densities used in the calculations and shown in Table 

2 are somewhat higher than are likely to be observed from vessels near 

the area of planned operations.

    Harbor Porpoise - Harbor Porpoise densities were estimated from 

industry data collected during 2006-2008 activities in the Chukchi Sea. 

Prior to 2006, no reliable estimates were available for the Chukchi Sea 

and harbor porpoise presence was expected to be very low and limited to 

nearshore regions. For this reason, the data collected from industry 

vessels was considered to be the best available data. Observers on 

industry vessels in 2006-2008, however, recorded sightings throughout 

the Chukchi Sea during the summer and early fall months. Density 

estimates from 2006-2008 observations during non-seismic periods and 

locations in July-August ranged from 0.0009/km\2\ to 0.0016/km\2\ with 

a maximum 95 percent CI of 0.0016/km\2\ (Haley et al. 2009b). The 

median value from the summer season of those three years (0.0011/km\2\) 

was used as the average open-water density estimate while the high 

value (0.0016/km\2\) was used as the maximum estimate (Table 1). Harbor 

porpoise are not expected to be present in higher numbers near ice, so 

the open-water densities were used for ice-margin habitat in both 

seasons. Harbor porpoise densities recorded during industry operations 

in the fall months of 2006-2008 were slightly lower and ranged from 

0.0002/km\2\ to 0.0013/km\2\ with a maximum 95 percent CI of 0.0044/

km\2\. The median value (0.0010/km\2\) was again used as the average 

density estimate and the high value (0.0013/km\2\) was used as the 

maximum estimate (Table 2).

    Other Cetaceans - The remaining four cetacean species that could be



[[Page 32393]]



encountered in the Chukchi Sea during Statoil's planned seismic survey 

include the humpback whale, killer whale, minke whale, and fin whale. 

Although there is evidence of the occasional occurrence of these 

animals in the Chukchi Sea, it is unlikely that more than a few 

individuals will be encountered during the proposed activities. George 

and Suydam (1998) reported killer whales, Brueggeman et al. (1990) and 

Haley et al. (2009b) reported minke whale, and COMIDA (2009) and Haley 

et al. (2009b) reported fin whales off of Ledyard Bay in the Chukchi 

Sea.

(2) Pinnipeds

    Four species of pinnipeds may be encountered in the Chukchi Sea: 

ringed seal, bearded seal, spotted seal, and ribbon seal. Each of these 

species, except the spotted seal, is associated with both the ice 

margin and the nearshore area. The ice margin is considered preferred 

habitat (as compared to the nearshore areas) during most seasons.

    Ringed and Bearded Seals - Ringed seal and bearded seal average 

summer ice-margin densities (Table 1) were available in Bengtson et al. 

(2005) from spring surveys in the offshore pack ice zone (zone 12P) of 

the northern Chukchi Sea. However, corrections for bearded seal 

availability, g(0), based on haulout and diving patterns were not 

available. Densities of ringed and bearded seals in open water are 

expected to be somewhat lower in the summer when preferred pack ice 

habitat may still be present in the Chukchi Sea. Average and maximum 

open-water densities have been estimated as 3/4 of the ice margin 

densities during the summer for both species. The fall density of 

ringed seals in the offshore Chukchi Sea has been estimated as 2/3 the 

summer densities because ringed seals begin to reoccupy nearshore fast 

ice areas as it forms in the fall. Bearded seals may begin to leave the 

Chukchi Sea in the fall, but less is known about their movement 

patterns so fall densities were left unchanged from summer densities. 

For comparison, the ringed seal density estimates calculated from data 

collected during summer 2006micro2008 industry operations ranged from 

0.0082/km\2\ to 0.0221/km\2\ with a maximum 95 percent CI of 0.0577/

km\2\ (Haley et al. 2009b). These estimates are lower than those made 

by Bengtson et al. (2005) which is not surprising given the different 

survey methods and timing.

    Spotted Seal - Little information on spotted seal densities in 

offshore areas of the Chukchi Sea is available. Spotted seals are often 

considered to be predominantly a coastal species except in the spring 

when they may be found in the southern margin of the retreating sea 

ice, before they move to shore. However, satellite tagging has shown 

that they sometimes undertake long excursions into offshore waters 

during summer (Lowry et al. 1994, 1998). Spotted seal densities in the 

summer were estimated by multiplying the ringed seal densities by 0.02. 

This was based on the ratio of the estimated Chukchi populations of the 

two species. Chukchi Sea spotted seal abundance was estimated by 

assuming that 8% of the Alaskan population of spotted seals is present 

in the Chukchi Sea during the summer and fall (Rugh et al. 1997), the 

Alaskan population of spotted seals is 59,214 (Angliss and Allen 2009), 

and that the population of ringed seals in the Alaskan Chukchi Sea is 

>208,000 animals (Bengtson et al. 2005). In the fall, spotted seals 

show increased use of coastal haulouts so densities were estimated to 

be 2/3 of the summer densities.

    Ribbon Seal - Ribbon seals have been reported in very small numbers 

within the Chukchi Sea by observers on industry vessels (two sightings; 

Haley et al. 2009b). The resulting density estimate of 0.0003/km\2\ was 

used as the average density and a multiplier of 4 was used as the 

estimated maximum density for both seasons and habitat zones.



Potential Number of Takes by Harassment



    This subsection provides estimates of the number of individuals 

potentially exposed to sound levels micro160 dB re 1 microPa (rms). The 

estimates are based on a consideration of the number of marine mammals 

that might be disturbed appreciably by operations in the Chukchi Sea 

and the anticipated area exposed to rms sound levels of 160 dB.

    As described above, marine mammal density estimates for the Chukchi 

Sea have been derived for two time periods, the summer period (July-

August), and the fall period (September-October). Animal densities 

encountered in the Chukchi Sea during both of these time periods will 

further depend on the habitat zone within which the source vessel is 

operating, i.e., open water or ice margin. The seismic source vessel is 

not an icebreaker and cannot tow survey equipment through pack ice. 

Under this assumption, densities of marine mammals expected to be 

observed near ice margin areas have been applied to 10% of the proposed 

3D survey area and 2D tracklines in both seasons. Densities of marine 

mammals expected to occur in open water areas have been applied to the 

remaining 90% of the 3D survey and 2D tracklines area in both seasons.

    The number of individuals of each species potentially exposed to 

received levels micro160 dB re 1 microPa (rms) within each season and 

habitat zone was estimated by multiplying

     the anticipated area to be ensonified to the specified 

level in each season and habitat zone to which that density applies, by

     the expected species density.

    The numbers of individuals potentially exposed were then summed for 

each species across the two seasons and habitat zones. Some of the 

animals estimated to be exposed, particularly migrating bowhead whales, 

might show avoidance reactions before being exposed to [gteqt]160 dB re 

1 microPa (rms). Thus, these calculations actually estimate the number 

of individuals potentially exposed to micro160 dB that would occur if 

there were no avoidance of the area ensonified to that level.

(1) 3D Seismic Survey Area

    The size of the proposed 3D seismic survey area is 915 mi\2\ (2,370 

km\2\) and located >100 mi (160 km) offshore. Approximately 1/4 of the 

area (~234 mi\2\, or ~606 km\2\) is expected to be surveyed in August 

(weather depending). This area, with a 160 dB radius of 8 mi (13 km) 

along each point of its perimeter equals a total area of ~1,081 mi\2\ 

(~2,799 km\2\). Summer marine mammal densities from Table 1 have been 

applied to this area. The other 3/4 of the survey area (~687 mi\2\, or 

~1,779 km\2\) is expected to be covered in September-October. This 

area, also with a 160 dB radius of 8 mi (13 km) along each point of its 

perimeter results in a total area of ~1,813 mi\2\ (~4,695 km\2\). Fall 

marine mammal densities from Table 2 have been applied to this area. 

Based on these assumptions and those described above, the estimates of 

marine mammals potentially exposed to sounds micro160 dB in the Chukchi 

Sea from seismic data acquisition in the 3D survey area were calculated 

in Table 3.

    For the common species, the requested numbers were calculated as 

described above and based on the average and maximum densities 

reported. For less common species, for which minimum density estimates 

were assumed, the numbers were set to a minimum to allow for chance 

encounters. The mitigation gun (60 in\3\) will be active during turns 

extending about 1.6 mi (2.5 km) outside the 3D survey area. The 

estimated 160 dB radius for the 60 in\3\ mitigation gun is 5,906 ft 

(1,800 m) and therefore falls well within the area expected to be



[[Page 32394]]



exposed to received sound levels of [gteqt]160 dB of the 3D survey 

area.



Table 3. Summary of the Number of Potential Exposures of Marine Mammals to Received Sound Levels in the Water of >160 dB During Statoil's Planned Marine

                                                    Seismic Survey in the Chukchi Sea, Alaska, 2010.

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

                                                            Number of Exposure to Sound     Number of Exposure to Sound     Total Number of Exposure to

                         Species                            Levels >160 dB re 1 microPa     Levels >160 dB re 1 microPa      Sound Levels >160 dB re 1

                                                            (rms) by 3D Seismic Survey      (rms) by 2D Seismic Survey             microPa (rms)

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

Beluga whale                                                                         97                              87                             184

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

Killer whale                                                                          1                               1                               2

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

Harbor porpoise                                                                       8                              13                              21

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

Bowhead whale                                                                        95                              63                             158

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

Gray whale                                                                           52                              92                             144

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

Humpback whale                                                                        1                               1                               2

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

Fin whale                                                                             1                               1                               2

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

Minke whale                                                                           1                               1                               2

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

Bearded seal                                                                         82                             132                             214

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

Ribbon seal                                                                           2                               4                               6

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

Ringed seal                                                                       2,253                           4,234                           6,487

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

Spotted seal                                                                         45                              85                             130

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



(2) 2D Seismic Survey Lines

    Seismic data along the ~420 mi (675 km) of four 2D survey 

tracklines might be acquired with the full airgun array if access to 

the 3D survey area is restricted (e.g., ice conditions), or 3D 

acquisition progress is better than anticipated. Under the assumption 

that these restrictive weather conditions will mainly be an issue in 

the early summer season, 80 % of the 2D tracklines are assumed to be 

acquired during August and 20% during the fall. The total area 

potentially exposed to micro160 dB from these tracklines was calculated 

with the trackline sections outside the 3D survey area. Excluding these 

sections results in a total trackline length of ~285 mi (460 km). With 

a 160 dB radius of ~8 mi (13 km) this results in a total exposed area 

of ~7,432 mi\2\ (11,960 km\2\). Such summer densities were used for 80% 

of the total area (5,945 mi\2\, or 9,568 km\2\) and fall densities for 

the remaining 20% (1,486 mi\2\, or 2,392 km\2\). Following a similar 

approach as for the 3D survey area, numbers of more common marine 

mammal species were calculated based on the average and maximum 

densities and for less common species the numbers were set to a minimum 

to allow for chance encounters. The results of estimates of marine 

mammals potentially exposed to sounds micro160 dB in the Chukchi Sea 

from seismic data acquisition along the 2D tracklines are presented in 

Table 3.



Estimated Take Conclusions



    Cetaceans - Effects on cetaceans are generally expected to be 

restricted to avoidance of an area around the seismic survey and short-

term changes in behavior, falling within the MMPA definition of ``Level 

B harassment''.

    Using the 160 dB criterion, the average estimates of the numbers of 

individual cetaceans exposed to sounds [gteqt]160 dB re 1 microPa (rms) 

represent varying proportions of the populations of each species in the 

Beaufort Sea and adjacent waters. For species listed as ``Endangered'' 

under the ESA, the estimates include approximately 158 bowheads. This 

number is approximately 1.11% of the Bering-Chukchi-Beaufort population 

of >14,247 assuming 3.4% annual population growth from the 2001 

estimate of >10,545 animals (Zeh and Punt 2005). For other cetaceans 

that might occur in the vicinity of the marine seismic survey in the 

Chukchi Sea, they also represent a very small proportion of their 

respective populations. The average estimates of the number of belugas, 

killer whales, harbor porpoises, gray whales, fin whales, humpback 

whales, and minke whales that might be exposed to [gteqt]160 dB re 1 

microPa (rms) are 183, 2, 21, 144, 2, 2, and 2. These numbers represent 

4.95%, 0.62%, 0.04%, 0.81%, 0.03%, 0.21%, and 0.19% of these species of 

their respective populations in the proposed action area.

    Seals - A few seal species are likely to be encountered in the 

study area, but ringed seal is by far the most abundant in this area. 

The average estimates of the numbers of individuals exposed to sounds 

at received levels [gteqt]160 dB re 1 microPa (rms) during the proposed 

seismic survey are as follows: ringed seals (6,487), bearded seals 

(215), spotted seals (129), and ribbon seals (6). These numbers 

represent 2.81%, 0.09%, 0.22%, and 0.01% of Alaska stocks of ringed, 

bearded, spotted, and ribbon seals.



Negligible Impact and Small Numbers Analysis and Preliminary 

Determination



    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.'' In making a negligible impact determination, NMFS considers 

a variety of factors, including but not limited to: (1) the number of 

anticipated mortalities; (2) the number and nature of anticipated 

injuries; (3) the number, nature, intensity, and duration of Level



[[Page 32395]]



B harassment; and (4) the context in which the takes occur.

    No injuries or mortalities are anticipated to occur as a result of 

Statoil's proposed 2010 open water marine seismic surveys in the 

Chukchi Seas, and none are proposed to be authorized. Additionally, 

animals in the area are not expected to incur hearing impairment (i.e., 

TTS or PTS) or non-auditory physiological effects. Takes will be 

limited to Level B behavioral harassment. Although it is possible that 

some individuals of marine mammals may be exposed to sounds from marine 

survey activities more than once, the expanse of these multi-exposures 

are expected to be less extensive since both the animals and the survey 

vessels will be moving constantly in and out of the survey areas.

    Most of the bowhead whales encountered during the summer will 

likely show overt disturbance (avoidance) only if they receive airgun 

sounds with levels [gteqt]160 dB re 1 microPa (rms). Odontocete 

reactions to seismic energy pulses are usually assumed to be limited to 

shorter distances from the airgun(s) than are those of mysticetes, 

probably in part because odontocete low-frequency hearing is assumed to 

be less sensitive than that of mysticetes. However, at least when in 

the Canadian Beaufort Sea in summer, belugas appear to be fairly 

responsive to seismic energy, with few being sighted within 6-12 mi 

(10-20 km) of seismic vessels during aerial surveys (Miller et al. 

2005). Belugas will likely occur in small numbers in the Chukchi Sea 

during the survey period and few will likely be affected by the survey 

activity. In addition, due to the constant moving of the seismic survey 

vessel, the duration of the noise exposure by cetaceans to seismic 

impulse would be brief. For the same reason, it is unlikely that any 

individual animal would be exposed to high received levels multiple 

times.

    Taking into account the mitigation measures that are planned, 

effects on cetaceans are generally expected to be restricted to 

avoidance of a limited area around the survey operation and short-term 

changes in behavior, falling within the MMPA definition of ``Level B 

harassment''.

    Furthermore, the estimated numbers of animals potentially exposed 

to sound levels sufficient to cause appreciable disturbance are very 

low percentages of the population sizes in the Bering-Chukchi-Beaufort 

seas, as described above.

    The many reported cases of apparent tolerance by cetaceans of 

seismic exploration, vessel traffic, and some other human activities 

show that co-existence is possible. Mitigation measures such as 

controlled vessel speed, dedicated marine mammal observers, non-

pursuit, and shut downs or power downs when marine mammals are seen 

within defined ranges will further reduce short-term reactions and 

minimize any effects on hearing sensitivity. In all cases, the effects 

are expected to be short-term, with no lasting biological consequence.

    Some individual pinnipeds may be exposed to sound from the proposed 

marine surveys more than once during the time frame of the project. 

However, as discussed previously, due to the constant moving of the 

survey vessel, the probability of an individual pinniped being exposed 

to multiple times is much lower than if the source is stationary. 

Therefore, NMFS has preliminarily determined that the exposure of 

pinnipeds to sounds produced by the proposed marine seismic survey in 

the Chukchi Sea is not expected to result in more than Level B 

harassment and is anticipated to have no more than a negligible impact 

on the animals.

    Of the twelve marine mammal species likely to occur in the proposed 

marine survey area, only the bowhead, fin, and humpback whales are 

listed as endangered under the ESA. These species are also designated 

as ``depleted'' under the MMPA. Despite these designations, the Bering-

Chukchi-Beaufort stock of bowheads has been increasing at a rate of 3.4 

percent annually for nearly a decade (Allen and Angliss, 2010). 

Additionally, during the 2001 census, 121 calves were counted, which 

was the highest yet recorded. The calf count provides corroborating 

evidence for a healthy and increasing population (Allen and Angliss, 

2010). The occurrence of fin and humpback whales in the proposed marine 

survey areas is considered very rare. There is no critical habitat 

designated in the U.S. Arctic for the bowhead, fin, and humpback whale. 

The bearded and ringed seals are ``candidate species'' under the ESA, 

meaning they are currently being considered for listing but are not 

designated as depleted under the MMPA. None of the other three species 

that may occur in the project area are listed as threatened or 

endangered under the ESA or designated as depleted under the MMPA.

    Potential impacts to marine mammal habitat were discussed 

previously in this document (see the ``Anticipated Effects on Habitat'' 

section). Although some disturbance is possible to food sources of 

marine mammals, the impacts are anticipated to be minor enough as to 

not affect rates of recruitment or survival of marine mammals in the 

area. Based on the vast size of the Arctic Ocean where feeding by 

marine mammals occurs versus the localized area of the marine survey 

activities, any missed feeding opportunities in the direct project area 

would be minor based on the fact that other feeding areas exist 

elsewhere.

    The estimated takes proposed to be authorized represent 4.95% of 

the Eastern Chukchi Sea population of approximately 3,700 beluga whales 

(Angliss and Allen 2009), 0.62% of Aleutian Island and Bering Sea stock 

of approximately 340 killer whales, 0.04% of Bering Sea stock of 

approximately 48,215 harbor porpoises, 0.81% of the Eastern North 

Pacific stock of approximately 17,752 gray whales, 1.11% of the Bering-

Chukchi-Beaufort population of 14,247 individuals assuming 3.4 percent 

annual population growth from the 2001 estimate of 10,545 animals (Zeh 

and Punt, 2005), 0.21% of the Western North Pacific stock of 

approximately 938 humpback whales, 0.03% of the North Pacific stock of 

approximately 5,700 fin whales, and 0.19% of the Alaska stock of 

approximately 1,003 minke whales. The take estimates presented for 

bearded, ringed, spotted, and ribbon seals represent 0.09, 2.81, 0.22, 

and 0.01 percent of U.S. Arctic stocks of each species, respectively. 

These estimates represent the percentage of each species or stock that 

could be taken by Level B behavioral harassment if each animal is taken 

only once. In addition, the mitigation and monitoring measures 

(described previously in this document) proposed for inclusion in the 

IHA (if issued) are expected to reduce even further any potential 

disturbance to marine mammals.

    Based on the analysis contained herein of the likely effects of the 

specified activity on marine mammals and their habitat, and taking into 

consideration the implementation of the mitigation and monitoring 

measures, NMFS preliminarily finds that Statoil's proposed 2010 open 

water marine seismic survey in the Chukchi Sea may result in the 

incidental take of small numbers of marine mammals, by Level B 

harassment only, and that the total taking from the marine surveys will 

have a negligible impact on the affected species or stocks.



[[Page 32396]]



Impact on Availability of Affected Species or Stock for Taking for 

Subsistence Uses



Relevant Subsistence Uses



    The disturbance and potential displacement of marine mammals by 

sounds from the proposed marine surveys are the principal concerns 

related to subsistence use of the area. Subsistence remains the basis 

for Alaska Native culture and community. Marine mammals are legally 

hunted in Alaskan waters by coastal Alaska Natives. In rural Alaska, 

subsistence activities are often central to many aspects of human 

existence, including patterns of family life, artistic expression, and 

community religious and celebratory activities. Additionally, the 

animals taken for subsistence provide a significant portion of the food 

that will last the community throughout the year. The main species that 

are hunted include bowhead and beluga whales, ringed, spotted, and 

bearded seals, walruses, and polar bears. (Both the walrus and the 

polar bear are under the USFWS' jurisdiction.) The importance of each 

of these species varies among the communities and is largely based on 

availability.

    Subsistence hunting and fishing continue to be prominent in the 

household economies and social welfare of some Alaskan residents, 

particularly among those living in small, rural villages (Wolfe and 

Walker 1987). Subsistence remains the basis for Alaska Native culture 

and community. In rural Alaska, subsistence activities are often 

central to many aspects of human existence, including patterns of 

family life, artistic expression, and community religious and 

celebratory activities.

    Marine mammals are legally hunted in Alaskan waters by coastal 

Alaska Natives; species hunted include bowhead and beluga whales; 

ringed, spotted, and bearded seals; walruses, and polar bears. The 

importance of each of the various species varies among the communities 

based largely on availability. Bowhead whales, belugas, and walruses 

are the marine mammal species primarily harvested during the time of 

the proposed seismic survey. There is little or no bowhead hunting by 

the community of Point Lay, so beluga and walrus hunting are of more 

importance there. Members of the Wainwright community hunt bowhead 

whales in the spring, although bowhead whale hunting conditions there 

are often more difficult than elsewhere, and they do not hunt bowheads 

during seasons when Statoil's seismic operation would occur. Depending 

on the level of success during the spring bowhead hunt, Wainwright 

residents may be very dependent on the presence of belugas in a nearby 

lagoon system during July and August. Barrow residents focus hunting 

efforts on bowhead whales during the spring and generally do not hunt 

beluga then. However, Barrow residents also hunt in the fall, when 

Statoil expects to be conducting seismic surveys (though not near 

Barrow).

(1) Bowhead Whales

    Bowhead whale hunting is a key activity in the subsistence 

economies of northwest Arctic communities. The whale harvests have a 

great influence on social relations by strengthening the sense of 

Inupiat culture and heritage in addition to reinforcing family and 

community ties.

    An overall quota system for the hunting of bowhead whales was 

established by the International Whaling Commission (IWC) in 1977. The 

quota is now regulated through an agreement between NMFS and the Alaska 

Eskimo Whaling Commission (AEWC). The AEWC allots the number of bowhead 

whales that each whaling community may harvest annually (USDI/BLM 

2005). The annual take of bowhead whales has varied due to (a) changes 

in the allowable quota level and (b) year-to-year variability in ice 

and weather conditions, which strongly influence the success of the 

hunt.

    Bowhead whales migrate around northern Alaska twice each year, 

during the spring and autumn, and are hunted in both seasons. Bowhead 

whales are hunted from Barrow during the spring and the fall migration 

and animals are not successfully harvested every year. The spring hunt 

along Chukchi villages and at Barrow occurs after leads open due to the 

deterioration of pack ice; the spring hunt typically occurs from early 

April until the first week of June. The fall migration of bowhead 

whales that summer in the eastern Beaufort Sea typically begins in late 

August or September. Fall migration into Alaskan waters is primarily 

during September and October.

    In the fall, subsistence hunters use aluminum or fiberglass boats 

with outboards. Hunters prefer to take bowheads close to shore to avoid 

a long tow during which the meat can spoil, but Braund and Moorehead 

(1995) report that crews may (rarely) pursue whales as far as 50 mi (80 

km). The autumn bowhead hunt usually begins in Barrow in mid-September, 

and mainly occurs in the waters east and northeast of Point Barrow.

    The scheduling of this seismic survey has been discussed with 

representatives of those concerned with the subsistence bowhead hunt, 

most notably the AEWC, the Barrow Whaling Captains' Association, and 

the North Slope Borough (NSB) Department of Wildlife Management.

    The planned mobilization and start date for seismic surveys in the 

Chukchi Sea (~20 July and ~1 August) is well after the end of the 

spring bowhead migration and hunt at Wainwright and Barrow. Seismic 

operations will be conducted far offshore from Barrow and are not 

expected to conflict with subsistence hunting activities. Specific 

concerns of the Barrow whaling captains are addressed as part of the 

Plan of Cooperation with the AEWC (see below).

(2) Beluga Whales

    Beluga whales are available to subsistence hunters along the coast 

of Alaska in the spring when pack-ice conditions deteriorate and leads 

open up. Belugas may remain in coastal areas or lagoons through June 

and sometimes into July and August. The community of Point Lay is 

heavily dependent on the hunting of belugas in Kasegaluk Lagoon for 

subsistence meat. From 1983-1992 the average annual harvest was ~40 

whales (Fuller and George 1997). In Wainwright and Barrow, hunters 

usually wait until after the spring bowhead whale hunt is finished 

before turning their attention to hunting belugas. The average annual 

harvest of beluga whales taken by Barrow for 1962-1982 was five (MMS 

1996). The Alaska Beluga Whale Committee recorded that 23 beluga whales 

had been harvested by Barrow hunters from 1987 to 2002, ranging from 0 

in 1987, 1988 and 1995 to the high of 8 in 1997 (Fuller and George 

1997; Alaska Beluga Whale Committee 2002 in USDI/BLM 2005). The seismic 

survey activities take place well offshore, far away from areas that 

are used for beluga hunting by the Chukchi Sea communities. It is 

possible, but unlikely, that accessibility to belugas during the 

subsistence hunt could be impaired during the survey.

(3) Ringed Seals

    Ringed seals are hunted mainly from October through June. Hunting 

for these smaller mammals is concentrated during winter because bowhead 

whales, bearded seals and caribou are available through other seasons. 

In winter, leads and cracks in the ice off points of land and along the 

barrier islands are used for hunting ringed seals. The average annual 

ringed seal harvest was 49 seals in Point Lay, 86 in Wainwright, and 

394 in Barrow (Braund et al. 1993; USDI/BLM 2003, 2005). Although 

ringed seals are available year-round, the seismic



[[Page 32397]]



survey will not occur during the primary period when these seals are 

typically harvested. Also, the seismic survey will be largely in 

offshore waters where the activities will not influence ringed seals in 

the nearshore areas where they are hunted.

(4) Spotted Seals

    The spotted seal subsistence hunt peaks in July and August along 

the shore where the seals haul out, but usually involves relatively few 

animals. Spotted seals typically migrate south by October to overwinter 

in the Bering Sea. During the fall migration spotted seals are hunted 

by the Wainright and Point Lay communities as the seals move south 

along the coast (USDI/BLM 2003). Spotted seals are also occasionally 

hunted in the area off Point Barrow and along the barrier islands of 

Elson Lagoon to the east (USDI/BLM 2005). The seismic survey will 

remain offshore of the coastal harvest area of these seals and should 

not conflict with harvest activities.

(5) Bearded Seals

    Bearded seals, although generally not favored for their meat, are 

important to subsistence activities in Barrow and Wainright, because of 

their skins. Six to nine bearded seal hides are used by whalers to 

cover each of the skin-covered boats traditionally used for spring 

whaling. Because of their valuable hides and large size, bearded seals 

are specifically sought. Bearded seals are harvested during the spring 

and summer months in the Chukchi Sea (USDI/BLM 2003, 2005). The animals 

inhabit the environment around the ice floes in the drifting nearshore 

ice pack, so hunting usually occurs from boats in the drift ice. Most 

bearded seals are harvested in coastal areas inshore of the proposed 

survey so no conflicts with the harvest of bearded seals are expected.

    In the event that both marine mammals and hunters are near the 3D 

survey area when seismic surveys are in progress, the proposed project 

potentially could impact the availability of marine mammals for harvest 

in a small area immediately around the vessel, in the case of 

pinnipeds, and possibly in a large area in the case of migrating 

bowheads. However, the majority of marine mammals are taken by hunters 

within ~21 mi (~33 km) from shore (Figure 2 in Statoil's IHA 

application), and the seismic source vessel M/V Geo Celtic will remain 

far offshore, well outside the hunting areas. Considering the timing 

and location of the proposed seismic survey activities, as described 

earlier in the document, the proposed project is not expected to have 

any significant impacts to the availability of marine mammals for 

subsistence harvest. Specific concerns of the respective communities 

are addressed as part of the Plan of Cooperation between Statoil and 

the AEWC.



Potential Impacts to Subsistence Uses



    NMFS has defined ``unmitigable adverse impact'' in 50 CFR 216.103 

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.

    Noise and general activity during Statoil's proposed open water 

marine seismic survey have the potential to impact marine mammals 

hunted by Native Alaskans. In the case of cetaceans, the most common 

reaction to anthropogenic sounds (as noted previously in this document) 

is avoidance of the ensonified area. In the case of bowhead whales, 

this often means that the animals divert from their normal migratory 

path by several kilometers. Additionally, general vessel presence in 

the vicinity of traditional hunting areas could negatively impact a 

hunt.

    In the case of subsistence hunts for bowhead whales in the Chukchi 

Sea, there could be an adverse impact on the hunt if the whales were 

deflected seaward (further from shore) in traditional hunting areas. 

The impact would be that whaling crews would have to travel greater 

distances to intercept westward migrating whales, thereby creating a 

safety hazard for whaling crews and/or limiting chances of successfully 

striking and landing bowheads.



Plan of Cooperation (POC or Plan)



    Regulations at 50 CFR 216.104(a)(12) require IHA applicants for 

activities that take place in Arctic waters to provide a POC or 

information that identifies what measures have been taken and/or will 

be taken to minimize adverse effects on the availability of marine 

mammals for subsistence purposes.

    Statoil states that it intends to maintain an open and transparent 

process with all stakeholders throughout the life-cycle of activities 

in the Chukchi Sea. Statoil began the stakeholder engagement process in 

2009 with meeting Chukchi Sea community leaders at the tribal, city, 

and corporate level. Statoil will continue to engage with leaders, 

community members, and subsistence groups, as well as local, state, and 

federal regulatory agencies throughout the exploration and development 

process.

    As part of stakeholder engagement, Statoil is developing a Plan of 

Cooperation (POC) for the proposed 2010 seismic acquisition. The POC 

summarizes the actions Statoil will take to identify important 

subsistence activities, inform subsistence users of the proposed survey 

activities, and obtain feedback from subsistence users regarding how to 

promote cooperation between subsistence activities and the Statoil 

program.

    Statoil has had the opportunity to engage with North Slope 

subsistence communities on several occasions:

     October 27, 2009, presentation to the NSB Planning 

Commission in Barrow;

     October 27 through November 5, 2009, Leadership Meetings 

in Barrow, Wainwright, Point Lay, and Kotzebue. Meetings with Native 

Village of Point Hope Executive Director;

     December 14, 2009, meeting the NSB Wildlife Department and 

members of the AEWC to discuss proposed activities, potential impacts, 

and measures for mitigating impacts;

     January 2010, POC meetings in Barrow, Wainwright, Point 

Lay, and Point Hope;

     March 22, 2010, Marine Mammal Co-Management Group Meeting; 

and

     April 13 - 16, 2010, Seminars presenting research work on 

oil spill contingencies in Arctic environmental conditions. Statoil 

took part and together with other operators brought Norwegian and 

international researchers to Anchorage, Barrow, and Kotzebue to present 

results from this research project (also called the SINTEF JIP study).

    Statoil states that consultation, both formal and informal, will 

continue before, during and after the 2010 seismic survey activities. A 

final POC that documents all consultations with community leaders, 

subsistence users groups, individual subsistence users, and community 

members will be submitted to NMFS, USFWS, and MMS upon completion of 

consultation. The final POC will include feedback from the Leadership 

Meetings and POC meetings. Statoil will continue to document all 

consultation with the communities and subsistence stakeholders.



[[Page 32398]]



Subsistence Mitigation Measures



    Statoil plans to introduce the following mitigation measures, plans 

and programs to potentially affected subsistence groups and 

communities. These measures, plans, and programs have been effective in 

past seasons of work in the Arctic and were developed in past 

consultations with these communities. These measures, plans, and 

programs will be implemented by Statoil during its 2010 open water 

marine seismic survey in the Chukchi Sea to monitor and mitigate 

potential impacts to subsistence users and resources. The mitigation 

measures Statoil has adopted and will implement during 2010 are listed 

and discussed below.

    Statoil will not be entering the Chukchi Sea until early August, so 

there will be no potential conflict with spring bowhead whale or beluga 

subsistence whaling in the polynya zone. Statoil's seismic survey area 

is ~100 mi (~ 161 km) northwest of Wainwright which reduces the 

potential impact to subsistence hunting activities occurring along the 

Chukchi Sea coast.

    The communication center in Wainwright will be jointly funded by 

Statoil and other operators, and Statoil will routinely call the 

communication center according to the established protocol while in the 

Chukchi Sea. Statoil plans to have one major crew change which will 

take place in Nome, AK, and will not involve the use of helicopters. 

Statoil does have a contingency plan for a potential transfer of a 

small number of crew via ship-to-shore vessel at Wainwright. If this 

should become necessary, the Wainwright communications center will be 

contacted to determine the appropriate vessel route and timing to avoid 

potential conflict with subsistence users.



Unmitigable Adverse Impact Analysis and Preliminary Determination



    NMFS has preliminarily determined that Statoil's proposed 2010 open 

water marine seismic survey in the Chukchi Sea will not have an 

unmitigable adverse impact on the availability of species or stocks for 

taking for subsistence uses. This preliminary determination is 

supported by information contained in this document and Statoil's draft 

POC. Statoil has adopted a spatial and temporal strategy for its 

Chukchi Sea operations that should minimize impacts to subsistence 

hunters. Statoil will enter the Chukchi Sea far offshore, so as to not 

interfere with July hunts in the Chukchi Sea villages. After the close 

of the July beluga whale hunts in the Chukchi Sea villages, very little 

whaling occurs in Wainwright, Point Hope, and Point Lay. Although the 

fall bowhead whale hunt in Barrow will occur while Statoil is still 

operating (mid- to late September to October), Barrow is approximately 

150 mi (241 km) east of the eastern boundary of the proposed marine 

seismic survey site. Based on these factors, Statoil's Chukchi Sea 

seismic survey is not expected to interfere with the fall bowhead 

harvest in Barrow. In recent years, bowhead whales have occasionally 

been taken in the fall by coastal villages along the Chukchi coast, but 

the total number of these animals has been small.

    Adverse impacts are not anticipated on sealing activities since the 

majority of hunts for seals occur in the winter and spring, when 

Statoil will not be operating. Additionally, most sealing activities 

occur much closer to shore than Statoil's proposed marine seismic 

survey area.

    Based on the measures described in Statoil's Draft POC, the 

proposed mitigation and monitoring measures (described earlier in this 

document), and the project design itself, NMFS has determined 

preliminarily that there will not be an unmitigable adverse impact on 

subsistence uses from Statoil's open water marine seismic survey in the 

Chukchi Sea.



Endangered Species Act (ESA)



    There are three marine mammal species listed as endangered under 

the ESA with confirmed or possible occurrence in the proposed project 

area: the bowhead, humpback, and fin whales. NMFS' Permits, 

Conservation and Education Division has initiated consultation with 

NMFS' Protected Resources Division under section 7 of the ESA on the 

issuance of an IHA to Statoil under section 101(a)(5)(D) of the MMPA 

for this activity. Consultation will be concluded prior to a 

determination on the issuance of an IHA.



National Environmental Policy Act (NEPA)



    NMFS is currently preparing an Environmental Assessment, pursuant 

to NEPA, to determine whether or not this proposed activity may have a 

significant effect on the human environment. This analysis will be 

completed prior to the issuance or denial of the IHA.



Proposed Authorization



    As a result of these preliminary determinations, NMFS proposes to 

authorize the take of marine mammals incidental to Statoil's 2010 open 

water seismic survey in the Chukchi Sea, Alaska, provided the 

previously mentioned mitigation, monitoring, and reporting requirements 

are incorporated.



    Dated: June 2, 2010.

James H. Lecky,

Director, Office of Protected Resources, National Marine Fisheries 

Service.

[FR Doc. 2010-13753 Filed 6-7-10; 8:45 am]

BILLING CODE 3510-22-S`