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###### Department of Commerce

###### National Oceanic and Atmospheric Administration

          - RIN 0648-XJ71

# AGENCY:

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

# ACTION:

Notice of issuance of a marine mammal incidental take authorization.

# SUMMARY:

 In accordance with provisions of the Marine Mammal Protection Act (MMPA) as amended, notification is hereby given that an Incidental Harassment Authorization (IHA) to take marine mammals, by Level B harassment, incidental to conducting open water shallow hazard and site clearance surveys by ConocoPhillips Alaska, Inc. (CPAI) in the Chukchi Sea has been issued.

# DATES:

 The authorization is effective from August 15, 2008, until October 31, 2008.

# ADDRESSES:

                         A copy of the application, IHA, the                         *Final Programmatic Environmental Assessment for Arctic Ocean Outer Continental Shelf Seismic Surveys—2006*                         (2006 PEA) prepared by the Minerals Management Service (MMS), the 2008 Supplemental Environmental Assessment (SEA) for the Issuance of five IHAs for open water seismic surveys and shallow hazard and site clearance surveys in the Arctic, and/or a list of references used in this document may be obtained by writing to P. Michael Payne, Chief, Permits, Conservation and Education Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-3225, or by telephoning one of the contacts listed here (see                         **FOR FURTHER INFORMATION CONTACT**                        ).                    

# FOR FURTHER INFORMATION CONTACT:

 Shane Guan, Office of Protected Resources, NMFS, (301) 713-2289, ext 137 or Brad Smith, Alaska Region, NMFS, (907) 271-5006.

# SUPPLEMENTARY INFORMATION:

## Background

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

Authorization shall be granted if NMFS finds that the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for certain subsistence uses, and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring and reporting of such takings are set forth. NMFS has defined “negligible impact” in 50 CFR 216.103 as “...an impact resulting from the specified activity that cannot be reasonably expected to, and is not reasonably likely to, adversely affect the species or stock through effects on annual rates of recruitment or survival.”

Section 101(a)(5)(D) of the MMPA established an expedited process by which citizens of the United States can apply for an authorization to incidentally take small numbers of marine mammals by harassment. Except with respect to certain activities not pertinent here, the MMPA defines “harassment” as:

any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild [Level A harassment]; or (ii) has the potential to disturb a marine mammal or marine mammal stock in the wild by causing disruption of behavioral patterns, including, but not limited to, migration, breathing, nursing, breeding, feeding, or sheltering [Level B harassment].

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

## Summary of Request

                    On April 30, 2008, NMFS received an application from CPAI for the taking, by Level B harassment, of several species of marine mammals incidental to conducting shallow hazard and site clearance surveys using acoustic equipment and small airguns in the Chukchi Sea for 30-45 days from approximately August 10, 2008 until October 31, 2008. The geographic region of the proposed activities includes two areas spaced about 60 km (37 mi) apart and a path for sampling conditions along a potential pipeline route. Each area is about 2,000 km2                     (772.5 mi2                    ) with dimensions about 72 km (45 mi) by 62 km (38.5 mi). The two areas are about 111 km (69 mi) off the Alaska coast, generally west from the village of Wainwright. The marine surveys will be performed from a seismic vessel.                

                    Detailed information on the shallow hazard and seismic surveys can be found in the CPAI application and in the                     **Federal Register**                     notice for the proposed IHA published on May 23, 2008 (73 FR 30064) (hereinafter “FR Notice of Proposed IHA”). No changes have been made to the proposed activities since publication of the FR Notice of Proposed IHA.                

## Comments and Responses

During the 30-day public comment period, NMFS received comments from the Marine Mammal Commission (Commission), the Native Village of Point Hope (NVPH); the North Slope Borough (NSB); the Alaska Eskimo Whaling Commission (AEWC); the Center for Biological Diversity (CBD), Pacific Environment, Natural Resources Defense Council and Alaska Wilderness League; Oceana and Ocean Conservancy; the Inupiat Community of the Arctic Slope (ICPS); Dr. David E. Bain of the University of Washington; and CPAI.

### General Comments

*Comment 1:*                     The Commission recommends that NMFS issue the IHA provided that (a) the proposed marine mammal mitigation and monitoring activities are carried out as described in NMFS' FR Notice of Proposed IHA; (b) operations be suspended immediately if a dead or seriously injured marine mammal is found in the vicinity of the operations and the death or injury could have occurred incidental to those operations; and (c) the list of species authorized to be taken be expanded to include fin whales.                

*Response:*                     NMFS concurs with the Commission's recommendation and will require the immediate suspension of seismic activities if a dead or injured marine mammal has been sighted within an area where the Holder of the IHA deployed and utilized seismic airguns within the past 24 hours.                

In addition, fin whales have been included in the list of species authorized to be taken by Level B harassment for the CPAI shallow hazard and site clearance surveys.

*Comment 2:*                     The NSB and ICAS point out that the CPAI application was incomplete because the proposed dates and duration of activities vary throughout the application documents. In addition, the NSB points out that the application has limited information                           ( print page 49422)                        about marine mammal distribution, movements, habitat use, population size and trends. In addition, the ICAS states that CPAI cannot have adequately provided estimates of the number and type of species taken, when the IHA application did not adequately acknowledge the uncertainties in the available data for this type of operation.                

*Response:*                     Comment noted. NMFS reviewed the CPAI application and verified the information provided within. At the time when CPAI submitted its application, no specific dates had been identified by CPAI, but a range of possible dates (i.e., July 15 through November 15, 2008) for the activity was noted. CPAI has since narrowed its operation window to between August 10 and October 31, 2008. CPAI also indicates that the seismic activities would take approximately 30-45 days, and it is likely to finish the operation earlier if weather permits.                

While information on marine mammals is lacking, NMFS conducted relevant research so that complete information is provided in the FR Notice of Proposed IHA. In addition, detailed and updated information on bowhead whales and other marine mammal species is provided in the MMS 2006 PEA, MMS 2007 draft PEIS, NMFS 2008 SEA, and the SAR, as referenced in the FR Notice of Proposed IHA.

*Comment 3:*                     The NSB and ICAS recommend that NMFS not authorize CPAI's proposed seismic activities. The CBD also urges NMFS not to issue any take authorization to CPAI for the proposed activities unless and until the agency can ensure that mitigation measures are in place that truly avoid adverse impacts to all species and their habitats and only after full and adequate public participation has occurred and environmental review of the cumulative impacts of such activities on these species and their habitats has been undertaken. The CBD feels that the proposed IHA does not meet these standards and therefore violates the MMPA, ESA, NEPA, and other governing statutes and regulations.                

*Response:*                     NMFS does not agree with NSB, ICAS, and CBD's recommendation and CBD's assessment. In its FR Notice of Proposed IHA, NMFS outlined in detail the proposed mitigation and monitoring requirements. The implementation of these measures will reduce the impacts of the proposed survey on marine mammals and their surrounding environment to the lowest level practicable, as required by the MMPA. The public was given 30 days to review and comment on these measures, in accordance with section 101(a)(5)(D) of the MMPA. NMFS has prepared a Supplemental EA to the 2006 MMS PEA. NMFS has fulfilled its obligations under NEPA by completing a SEA, which is not required to be available for public comment prior to its finalization. Additionally, NMFS completed a Biological Opinion in July 2008, as required by section 7 of the ESA, which concluded that this action is not likely to jeopardize the continued existence of listed species or result in the destruction or adverse modification of critical habitat. Therefore, NMFS does not believe the issuance of an IHA to CPAI would result in a violation of the MMPA, ESA, NEPA, and other governing statutes and regulations.                

### Acoustics Impacts

*Comment 4:*                     Citing studies on noise impacts to chinchillas (Henderson                     *et al.*, 1991) and human noise exposure standards by the U.S. Occupational Safety Health Administration (OSHA), Dr. Bain states that “in humans, chronic exposure to levels of noise too low to generate a TTS can result in PTS.” As OSHA standards require limiting human exposure to noise at 115 dBA above threshold to 15 minutes per day, Dr. Bain concludes that this level is equivalent to 145 dB re 1 microPa for killer whales.                

*Response:*                     Although NMFS agrees that chronic exposure to noise levels that would not cause TTS could result in hearing impairment in the long-term, it is important to understand that such exposure has to be of a chronic and long-term nature. The OSHA standards for permissible exposure are based on daily impacts throughout an employee's career, while the noise exposure to seismic surveys by marine mammals is short-term and intermittent, as described in the FR Notice of Proposed IHA and in the MMS 2006 PEA. In addition, the reference Dr. Bain cites to (Henderson                     *et al.*, 1991) does not address chronic noise impact to humans. The research by Henderson                     *et al.*                     (1991) focused on the applicability of the equal energy hypothesis (EEH) to impact (impulse) noise exposures on chinchillas, and the results indicated that hearing loss resulting from exposure to impact noise did not conform to the predictions of the EEH, which is the basis for OSHA standards for continuous noise exposure.                

Most importantly, Dr. Bain's extrapolation of 145 dB re 1 microPa for killer whale hearing safety from OSHA's 115 dBA is fundamentally flawed for three reasons:

                    (1) The reference points when using decibel (dB) unit that address sound in air and in water are different. For airborne sounds, such as those by OSHA, the reference point is 20 microPa, while for underwater sounds, the reference point is 1 microPa. There are 26 dB differences between the values when different reference points are used for the same sound pressure, therefore, 115 dB re 20 microPa is 141 dB re 1 microPa for the same sound pressure. So 115 dB re 20 microPa in air above human threshold (defined as 0 dB re 20 microPa in air) would be 141 dB re 1 microPa underwater for the same sound pressure. Using the lowest threshold of 30 dB re 1 microPa as the killer whale hearing threshold, and assuming that noise impacts to killer whales are the same as for humans, one could extrapolate that continuous noise exposure of 171 dB re 1 microPa (141 dB over the 30 dB threshold) for 15 minutes for killer whales would be equivalent to humans exposed to 115 dB re 20 microPa for 15 minutes. Nevertheless, such extrapolation still leaves much uncertainty since marine mammals have a different mechanism for sound reception (Au, 1993; Richardson                     *et al.*, 1005). Some of the most recent science has shown that for some odontocetes, the onset of TTS when exposed to impulse noise is much higher (Finneran                     *et al.*, 2002) than NMFS' current thresholds.                

                    (2) The decibel values used by OSHA are expressed as broadband A-weighted sound levels expressed in dBA. This frequency-dependent weighting function is used to apply to the sound in accordance with the sensitivity of the human ear to different frequencies. Thus, it is inappropriate to compare these values to an animal's hearing capability, including how an animal perceives sound in air (Richardson                     *et al.*, 1995). For marine mammals, M-weighting functions have been suggested based on five different hearing functional groups to address different hearing sensitivities of different frequencies by each of the marine mammal groups (Southall                     *et al.*, 2007).                

(3) Finally, the sound characteristic used in OSHA standards is continuous sound, while the seismic sound from the proposed shallow hazard and site clearance surveys is impulse sound, which by its very nature is not a continuous sound.

*Comment 5:*                     Dr. Bain asserts that the zone of immediate risk of injury or death for marine mammals should be within the 150-215 dB re 1 microPa contours and assumes that values can be extrapolated from terrestrial species. Dr. Bain supports his argument by stating that immediate injury may result from                           ( print page 49423)                        brief exposure to sound levels that are 120 to 140 dB above threshold in terrestrial mammals, and that marine mammals vary in their best sensitivity from killer whales at around 30 dB re 1 microPa (killer whale) to 60 dB re 1 microPa (phocids) and 75 dB re 1 microPa (otariids)                

*Response:*                     NMFS does not agree with Dr. Bain's assessment. As discussed in                     *Response*                     to                     *Comment 3*, the reference points when using decibel (dB) unit that address sound in air is 20 microPa, while in water the reference point is 1 microPa. Therefore, the decibel levels used to address injury in terrestrial mammals cannot be extrapolated to apply marine mammal species without adding a correction factor of 26 dB (see Richardson                     *et al.*, 1995). Even so, plenty of controlled laboratory experiments on several marine mammal species (e.g., beluga whales, bottlenose dolphins, harbor seals, California sea lions, and northern elephant seals) in the past decade point out injuries (PTS) to marine mammals would probably occur at much higher sound exposure levels, far above the 180 and 190 dB re 1 microPa NMFS currently applies to protect cetaceans and pinnipeds from onset of Level A harassment (injury). (see review by Southall                     *et al.*, 2007).                

*Comment 6:*                     Citing OSHA (2007) standards for human noise exposure standards, Nachtigall                     *et al.*                     (2003), and Henderson                     *et al.*                     (1991), Dr. Bain extrapolates that permanent injury to hearing from repeated exposure to noise at 120 dB re 1 microPa would occur to killer whales after being exposed for 8 hours.                

*Response:*                     NMFS does not agree with Dr. Bain's assessment as such an extrapolation is invalid. First, as discussed in Response to Comment 4, the reference point addressing sound levels or intensities in air, which is used by OSHA for the human noise exposure standards, is relative to 20 microPa, while the reference point used to address sound levels or intensities in water is relative to 1 microPa. These are fundamentally different acoustical measures and should not be confused. Second, as discussed in                     *Response*                     to                     *Comment 5*, the noise exposure standard unit used by OSHA is dBA, which is the weighted sound exposure level based on human hearing sensitivities, and is not suitable to be used in other animals which have very different hearing sensitivities across the spectrum. Third, the sound sources used by OSHA are based on continuous sound, as is the referenced paper by Nachtigall                     *et al.*                     (2003), while the sound sources from the proposed seismic surveys are impulse sounds. The prediction of acoustic injury from continuous noise exposure is not applicable to impulse noise exposure, as is shown in the referenced paper by Henderson                     *et al.*                     (1991); therefore, the extrapolation is invalid. Fourth, ambient noise levels at many shallow water areas could easily reach 120 dB re 1 microPa, coupled with surf and wave actions. If killer whales suffered from permanent hearing damage when exposed to this noise level for 8 hours as suggested by Dr. Bain, then most killer whales in the coastal areas would have no hearing left. The lab controlled experiments by Nachtigall                     *et al.*                     (2003), as cited by Dr. Bain, show that an Atlantic bottlenose dolphin exhibited TTS of an average 11 dB after being exposed to continued noise up to 179 dB re 1 microPa for 55 minutes, a much higher level than where Dr. Bain would consider TTS to occur. However, in the wild, animals are expected to avoid such intense noise levels, thus preventing onset of TTS. Finally, killer whales are not expected to occur frequently in the proposed Arctic shallow hazard and site clearance project area, so the risk to this species is minimal.                

*Comment 7:*                     Citing several papers on killer whales, harbor porpoises, and marbeled murrelets, Dr. Bain states that major behavior changes of these animals appear to be associated with received levels of around 135 dB re 1 microPa, and that minor behavioral changes can occur at received levels from 90-110 dB re 1 microPa or lower. Citing his own studies, Dr. Bain states that “killer whales are 40% less likely to forage at all when vessels are nearby, perhaps because vessel noise masks echoes from prey, making the probability of foraging successfully negligible (Bain                     *et al.*                     2006ab).” In addition, Dr. Bain states that the threshold for effects on harbor porpoise is 90 dB re 1 microPa, for killer whale is 100 dB re 1 microPa, and for beluga whale is 153 dB re 1 microPa, which are all lower than the threshold used to estimate the takes. CBD also cited a study of Canadian beluga whales showing flight responses from ice-breakers at received sound levels as low as 94 dB. In addition, citing NRC (2003), the NVPH states that at distances of up to 50 km from icebreakers or other ships operating in deep channels, beluga whales respond with a suite of behavioral reactions which include rapid swimming away from the ship for distances up to 80 km. Finally, citing Richardson                     *et al.*                     (1999) and Richardson (2008), the NSB states that bowhead whales were excluded from a zone around an active seismic vessel where sound levels were estimated to be between 116 and 135 dB, and that bowhead whales were deflected away from sounds associated with a development island in the Beaufort Sea at levels perhaps approaching ambient sound levels.                

*Response:*                     NMFS does not agree with Dr. Bain, CBD, NVPH, and NSB's assessment. Although it is possible that marine mammals could react to any sound levels detectable above the ambient noise level within the animals' respective frequency response range, this does not mean that such animals would react in a biologically significant way. In addition, as discussed in                     *Response*                     to                     *Comment 5*, ambient noise levels in many of the world's ocean can easily exceed 90 dB re 1 microPa (Urick, 1983).                

                    According to experts on marine mammal behavior, the degree of reaction which constitutes a “take,” i.e., a reaction deemed to be biologically significant that could potentially disrupt the migration, breathing, nursing, breeding, feeding, or sheltering, etc. of a marine mammal is complex and context specific, and it depends on several variables in addition to the received level of the sound by the animals. These additional variables include, but are not limited to, other source characteristics (such as frequency range, duty cycle, continuous vs. impulse vs. intermittent sounds, duration, moving vs. stationary sources, etc.); specific species, populations, and/or stocks; prior experience of the animals (naive vs. previously exposed); habituation or sensitization of the sound by the animals; and behavior context (whether the animal perceives the sound as predatory or simply annoyance), etc. (Southall                     *et al.*, 2007).                

                    The references cited by Dr. Bain, CBD, NVPH, and NSB's second example in this comment address different source characteristics (continuous sound rather than impulse sound that are planned for the proposed shallow hazard and site clearance surveys) or species (killer whales and harbor proposes) that rarely occur in the proposed Arctic action area. No reference supporting the “threshold for effects” on beluga whales is provided by Dr. Bain. Much research regarding bowhead and gray whales response to seismic survey noises has been conducted in addition to marine mammal monitoring studies during prior seismic surveys. Detailed descriptions regarding behavior responses of these marine mammals to seismic sounds are available (e.g., Richardson                     *et al.*, 1995; review by Southall                     *et al.*, 2007), and are also discussed in this document.                          ( print page 49424)    

                    Although migrating bowhead whales were shown to be excluded from a zone around an active seismic vessel where sound levels were estimated to be at around 120 dB (Richardson                     *et al.*, 1999), the situation in this issue was that the migratory corridor was narrower in the Beaufort Sea. As the 120 dB ensonified area filled the narrow migratory corridor, thus impedes the movement of the whales. However, NMFS believes that in the Chukchi Sea where the area is more open, the 120 dB ensonified area would not impede bowhead whale migration. Therefore, there would be no significant biological affect to the species. However, as discussed below that monitoring a 120-dB radius in the Chukchi Sea is not practicable and due to safety concerns, NMFS would not require this level of monitoring in the Chukchi Sea.                

*Comment 8:*                     Dr. Bain states that sound sources are typically divided into continuous and pulsed categories, and that behavioral effects from pulsed sound are likely to be independent of the repetition rate and duty cycle, and depend primarily on the duration of the survey. Dr. Bain further states that intermittent pulses can result in continuously received noise when sound arrives via multiple paths, which Dr. Bain explains as “sound that bounces between the bottom and the surface will take longer to reach an animal than sound traveling via a direct path,” and that “noise can mask signals for a brief period before and after it is received, meaning an almost continuous received noise can mask signals continuously.” Dr. Bain concludes that “the subbottom profilers proposed for use during the site clearance surveys, with the very short intervals between pulses, present a risk of continuous masking effects.”                

*Response:*                     NMFS does not agree with Dr. Bain's statement on ocean acoustics and his subsequent analysis and assessment regarding underwater sound propagation and its effects to marine mammals. Within the scientific community on ocean acoustics and bioacoustics, two types of sounds are traditionally recognized: transient sounds (sounds of relatively short duration) and continuous sounds (sounds that go on and on). Transient sounds can be further classified into impulsive (such as seismic airguns, explosives, pile driving) and non-impulsive (such as military tactic sonars) sounds (Richardson                     *et al.*, 1995). Other researchers working on noise impacts to marine mammals classified sound types into a single pulse (such as a single explosive), multiple pulses (seismic airguns, pile driving), and nonpulses (ship, sonar) (Southall                     *et al.*, 2007). A simple way to distinguish pulses sound from nonpulses (continuous sound included) is that the former have rapid rise-time in relation to its extremely short duration. As mentioned in                     *Response*                     to                     *Comment 7*, behavioral responses from marine mammals when exposed to underwater noise is complex and context specific, and often depend on the sound characteristics (such as received levels, duration, duty cycles, frequency, etc.) and other variables.                

                    NMFS agrees that the distinction between transient and continuous sounds is not absolute, as continuous sound from a fast moving vessel is often treated as transient sound in relation to a stationary or slow moving marine mammal. Further, the distinction between pulses and nonpulses is also not always clear as certain pulsed sound sources (e.g., seismic airguns and explosives) may become nonpulses at greater distances due to signal decay through reverberation and other propagation paths. However, Dr. Bain's statement that intermittent pulses can result in continuously received noise when sound arrives via multiple paths is unfounded. For a marine mammal exposed to noise, multipath propagation would expose the animal to the noise multiple times, usually each subsequent exposure with lower sound level due to loss of acoustic energy from surface and bottom reflections; however, the noise arriving via multipath propagation would not become continuous sound because the intervals between signals would always exist. In addition, noise cannot mask a signal before or after it is received by the animal. Noise masking of signals can only occur when the unwanted sound (noise) interferes with the signal when received by the animal, generally at similar frequencies (Richardson                     *et al.*, 1995). Therefore, Dr. Bain's assessment that the subbottom profilers proposed for shallow hazard and site clearance surveys would cause continuous masking effects to marine mammals is not supported.                

*Comment 9:*                     Dr. Bain states that one characteristic of pulsed sources is known as “time-bandwidth” product, and he explains that it is “any sound with a finite duration (that is, any real-world sound) contains additional frequencies to the nominal frequency. That is, pulsed sources that nominally have a frequency that is too high to hear, may, in fact, be audible, as the source will contain lower frequencies that are detectable.”                

*Response:*                     NMFS does not agree with Dr. Bain's statement that high frequency pulsed sources nominally contain additional frequencies that are audible. The high frequency pulsed sources are expected to operate within their frequency range, although some mechanical noise at lower frequencies may be produced as a byproduct during the operation. The mechanical noise associated with acoustic equipment is expected to be low intensity and is not expected to result in harassment of marine mammals. Furthermore, the term “time-bandwidth product” is generally used in signal process, which is irrelevant to the proposed Arctic seismic survey.                

*Comment 10:*                     Dr. Bain states that the directionality of the sources and whether they are on during turns would also affect the ensonified area.                

*Response:*                     All acoustic sources are downward directional, thus no additional ensonified area would result during turns.                

*Comment 11:*                     The CBD argues that NMFS analysis of the various high-energy sound sources on marine mammals is deficient, with NMFS for the most part simply asserting that the sound generated by these sources is outside the hearing range of most marine mammals. The CBD further states that even NMFS acknowledges that odontocetes such as beluga whales can in fact hear these sounds.                

*Response:*                     NMFS does not agree with the CBD statement as it does not have scientific basis. In the FR Notice of the Proposed IHA, NMFS stated that the 445 kHz frequency band from the Klein System 3000 dual frequency digital side-scan sonar is outside any marine mammal species' hearing range, therefore, there would be no effect to marine mammals when this frequency is chosen. High frequency sounds above 200 kHz are clearly outside the hearing ranges for any marine mammals, which is well accepted among marine mammal bioacousticians (Richardson                     *et al.*, 1995; Southall                     *et al.*, 2007). In addition, NMFS never acknowledged that odontocetes such as beluga whales can hear sounds above 200 kHz (CBD did not provide any reference to support its statement.) Furthermore, the sound generated by various side-scan sonars operated at the frequency of 120 kHz and beyond produce signals above the hearing ranges for mysticetes, such as bowhead, gray, humpback, and minke whales (Richardson                     *et al.*, 1995; Southall                     *et al.*, 2007).                

### MMPA Comments

*Comment 12:*                     The CBD, ICAS, and NSB state that since NMFS has not promulgated any regulations related to shallow hazard and site clearance surveys under the MMPA, and because                           ( print page 49425)                        such surveys and associated activities carry the real potential of injury or death to marine mammals, neither an IHA nor an LOA can be issued for CPAI's proposed activities.                

*Response:*                     NMFS does not agree with the CBD, ICAS, and NSB's statement. Section 101(a)(5)(D) of the MMPA authorizes Level A (injury) harassment and Level B (behavioral) harassment takes. While NMFS' regulations indicate that a LOA must be issued if there is a potential for serious injury or mortality, NMFS does not believe that CPAI's shallow hazard and site clearance survey requires a LOA. As explained throughout this                     **Federal Register**                     Notice, it is highly unlikely that marine mammals would be exposed to sound pressure levels (SPLs) that could result in serious injury or mortality. The best scientific information indicates that an auditory injury is unlikely to occur as apparently sounds need to be significantly greater than 180 dB for injury to occur (Southall                     *et al.*, 2007).                

NMFS has determined that exposure to several seismic pulses at received levels near 200 205 dB (rms) might result in slight temporary threshold shift (TTS) (which is not considered injury) in hearing in a small odontocete, assuming the TTS threshold is a function of the total received pulse energy. Received levels of 200 205 dB or more from the loudest acoustic device would be restricted to a radius of no more than 5 m (16 ft) around a seismic vessel. CPAI's airgun array is considered to be of small size. For baleen whales, while there are no data, direct or indirect, on levels or properties of sound that are required to induce TTS, there is a strong likelihood that baleen whales (bowhead and gray whales) would avoid the approaching airguns (or vessel) before being exposed to levels high enough for there to be any possibility of onset of TTS. For pinnipeds, information indicates that for single seismic impulses, sounds would need to be higher than 190 dB rms for TTS to occur while exposure to several seismic pulses indicates that some pinnipeds may incur TTS at somewhat lower received levels than do small odontocetes exposed for similar durations. Consequently, NMFS has determined that it would be lawful to issue an IHA to CPAI for the 2008 seismic survey program.

*Comment 13:*                     The CBD states that it referenced the scientific literature linking seismic surveys with marine mammal stranding events in its comments to MMS on the 2006 Draft PEA and in comments to NMFS and MMS on the 2007 DPEIS. The CBD further states that NMFS' failure to address these studies and the threat of serious injury or mortality to marine mammals from seismic surveys renders NMFS' conclusory determination that serious injury or morality will not occur from CPAI's activities arbitrary and capricious.                

*Response:*                     The MMS briefly addressed the humpback whale stranding in Brazil on page PEA-127 in the 2006 Final PEA. Marine mammal strandings are also discussed in the MMS 2007 DPEIS. A more detailed response to the cited strandings has been provided in several previous IHA issuance notices for seismic surveys (e.g., 73 FR 40512, July 15, 2008). Additional information has not been provided by CBD or others regarding these strandings. As NMFS has stated, the evidence linking marine mammal strandings and seismic surveys remains tenuous at best. Two papers, Taylor                     *et al.*                     (2004) and Engel                     *et al.*                     (2004), reference seismic signals as a possible cause for a marine mammal stranding. Taylor                     *et al.*                     (2004) noted two beaked whale stranding incidents related to seismic surveys. The statement in Taylor                     *et al.*                     (2004) was that the seismic vessel was firing its airguns at 1300 hrs on September 24, 2004, and that between 1400 and 1600 hrs, local fishermen found live-stranded beaked whales some 22 km (12 nm) from the ship's location. A review of the vessel's trackline indicated that the closest approach of the seismic vessel and the beaked whales' stranding location was 33 km (18 nm) at 1430 hrs. At 1300 hrs, the seismic vessel was located 46 km (25 nm) from the stranding location. What is unknown is the location of the beaked whales prior to the stranding in relation to the seismic vessel, but the close timing of events indicates that the distance was not less than 33 km (18 nm). No physical evidence for a link between the seismic survey and the stranding was obtained. In addition, Taylor                     *et al.*                     (2004) indicates that the same seismic vessel was operating 500 km (270 nm) from the site of the Galapagos Island stranding in 2000. Whether the 2004 seismic survey caused two beaked whales to strand is a matter of considerable debate (see Cox                     *et al.*, 2004). NMFS believes that scientifically, these events do not constitute evidence that seismic surveys have an effect similar to that of mid-frequency tactical sonar. However, these incidents do point to the need to look for such effects during future seismic surveys. To date, follow-up observations on several scientific seismic survey cruises have not indicated any beaked whale stranding incidents.                

                    Engel                     *et al.*                     (2004), in a paper presented to the International Whaling Commission (IWC) in 2004 (SC/56/E28), mentioned a possible link between oil and gas seismic activities and the stranding of eight humpback whales (seven off the Bahia or Espirito Santo States and one off Rio de Janeiro, Brazil). Concerns about the relationship between this stranding event and seismic activity were raised by the International Association of Geophysical Contractors (IAGC). The IAGC (2004) argues that not enough evidence is presented in Engel                     *et al.*                     (2004) to assess whether or not the relatively high proportion of adult strandings in 2002 is anomalous. The IAGC contends that the data do not establish a clear record of what might be a “natural” adult stranding rate, nor is any attempt made to characterize other natural factors that may influence strandings. As stated previously, NMFS remains concerned that the Engel                     *et al.*                     (2004) article appears to compare stranding rates made by opportunistic sightings in the past with organized aerial surveys beginning in 2001. If so, then the data are suspect.                

Second, strandings have not been recorded for those marine mammal species expected to be harassed by seismic in the Arctic Ocean. Beaked whales and humpback whales, the two species linked in the literature with stranding events with a seismic component are either extralimital or not located in the Chukchi Sea where shallow hazard and site clearance survey would occur. Moreover, NMFS notes that in the Arctic, marine mammal observation and monitoring have been conducted by the 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; nor reported by NSB inhabitants. Finally, if bowhead and gray whales react to sounds at very low levels by making minor course corrections to avoid seismic noise and mitigation measures require CPAI to ramp-up the seismic array to avoid a startle effect, strandings are highly unlikely to occur in the Arctic Ocean. Ramping-up of the array will allow marine mammals the opportunity to vacate the area of ensonification and thus avoid any potential injury or impairment of their hearing capabilities. In conclusion, NMFS does not expect any marine mammals will incur serious injury or mortality as a result of CPAI's shallow hazard and site clearance survey in the Chukchi Sea in 2008.

*Comment 14:*                     The CBD states that NMFS failed to adequately specify                           ( print page 49426)                        CPAI's activities and impacts of vessels because neither CPAI's application nor NMFS' FR Notice of the Proposed IHA mention the various transit routes through U.S. waters in the Bering, Chukchi and/or Beaufort Seas that these vessels associated with CPAI's surveys would take.                

*Response:*                     The specified activity that has been proposed and for which an IHA has been requested is the use of seismic airguns to conduct oil and gas exploration. While the support vessels play a role in facilitating seismic operations, NMFS does not expect these operations to result in the incidental take of marine mammals. Since these support vessels are typically slow-moving, any risk of vessel collisions with marine mammals is expected to be minimal. Moreover, normal shipping and transit operations do not rise to a level requiring an authorization under the MMPA. To require IHAs and LOAs for standard shipping would affect NMFS' ability to review activities that have a potential to cause harm to marine mammal populations.                

*Comment 15:*                     The ICAS and NSB state that a “small take” finding is inadequate and thus cannot be supported with actual data for the proposed CPAI shallow hazard and site clearance survey, therefore, placing NMFS in the position of having to make an arbitrary decision. In addition, the CBD states that NMFS did not make the distinction between “small number” and “negligible impact” while making the decision in the FR Notice of the Proposed IHA.                

*Response:*                     NMFS does not agree with the ICAS, NSB, and CBD's statement. The analysis provided in the FR Notice of Proposed IHA clearly described in detail the numbers of bowhead, gray, and beluga whales, and ringed and bearded seals that may be potentially taken by Level B harassment as a result of the seismic operations in the Chukchi Sea. As clearly stated in the aforementioned                     **Federal Register**                     notice, take numbers of these species represent 0.09, 0.19, and 0.06 percent of the western Arctic stock of bowhead (population estimated at 10,545), eastern North Pacific stock of gray (population estimated at 18,178), and the Bering Sea stock of harbor porpoises (population estimated at 66,078), respectively; and 0.55 and 0.15 percent of the Alaska stocks of ringed (population estimated at 249,000 in the Chukchi Sea) and bearded seal (population estimated at 250,000-300,000 in the Bering and Chukchi Seas) populations within the Chukchi Sea, respectively. Although no take number was estimated for humpback, fin, minke, and killer whales, harbor porpoises, and spotted and ribbon seals in the vicinity of the project area due to their rare presence based in the Chukchi Sea, NMFS believes that the harassment of these species would be much less likely than those of bowhead and beluga whales and ringed and bearded seals. NMFS believes that the numbers for all affected species are small relative to their stock size. Separate detailed analyses on the levels of take by noise exposure and cumulative impacts to these marine mammal species and stocks from a wide spectrum in the past, current, and foreseeable future were also conducted and described in the aforementioned                     **Federal Register**                     notice, the MMS 2006 PEA, and NMFS 2008 SEA. These analyses led NMFS to conclude that while behavioral modifications, including temporarily vacating the area during the project period may be made by these species to avoid the resultant visual and acoustic disturbance, NMFS nonetheless found that this action would result in no more than a negligible impact on the affected marine mammal species and/or stocks. NMFS also found that the proposed action would not have an unmitigable adverse impact on the availability of such species or stocks for taking for subsistence uses.                

*Comment 16:*                     The CPAI states although for bowhead whales a current minimum population is estimated at 9,472, there are more data that gives a range of the population up to 13,000 individuals. CPAI requests NMFS to consider using the range that more accurately reflects the health of the population and its increased growth over the past few decades.                

*Response:*                     Comment noted. Although several recent studies have put the western Arctic stock of bowhead whales in the range of 13,000 individuals (Gerber                     *et al.*, 2007; Citta                     *et al.*, 2007), those studies were based on the projection of an approximate 3 percent increase from the most recent estimate conducted in 2004 (George                     *et al.*, 2004). However, it is important to recognize that this number (13,000) is merely a projection based on the stock assessment survey and does not represent the population estimate which is usually based on population abundance surveys. NMFS Stock Assessment Report defines the best stock estimate for the western Arctic bowhead whales at 10,545, the minimum at 9,472 individuals, respectively (Angliss and Outlaw, 2008). For the purpose of this activity, NMFS uses the best population estimate, i.e., 10,545.                

*Comment 17:*                     The ICAS points out that the population density estimates used in the IHA application to determine the estimated take of various species are uncertain because CPAI based population density estimates on the published report of marine mammal surveys conducted during the Shell and CPAI seismic program in the Chukchi Sea during 2007 (“LGL Report”). The ICAS further states that while these may be the most recent density estimates for the region, they do not include estimates for ribbon seals, beluga, humpback whales, or fin whales. Finally, the ICAS points out that only 22 percent of the total daylight observation effort from the main vessel, and 43 percent of the total daylight observation from chase/monitoring vessels for the Chukchi Sea survey was useable.                

*Response:*                     As ICAS states in its comment these are the most recent density estimates of marine mammal species/stocks in the vicinity of the proposed seismic survey area. Therefore, NMFS considers these data to best reflect the recent marine mammal distribution and abundance in the region. These density estimates were adjusted for sighting rates to account for animals present but not actually seen. As for those species and stocks whose density data are not available, such as beluga, humpback, and killer whales, and ribbon seals that could also be affected by Level B behavioral harassment, since the occurrence of these marine mammals is very rare within the proposed project area during the late summer and fall in the Chukchi Sea, take numbers cannot be estimated. However, should these animals occur in the project area, NMFS believes their take numbers would be much lower (including as a percentage of the affected species or stock) as compared to those marine mammals whose take numbers were calculated.                

*Comment 18:*                     The CBD, ICAS, and NSB state that NMFS' estimates of the number of marine mammals that may be harassed based on the assumption that sounds below 160 dB re 1 microPa (rms) do not constitute harassment is incorrect because an activity can constitute harassment if it has the “potential” to affect marine mammal behavior. In addition, the CBD argues that 160 dB threshold for belugas is similarly flawed, as it points out in previous IHA notices, NMFS has acknowledged the impacts of sounds on beluga even at significant distances from a sound source (up to 20 km).                

*Response:*                     NMFS does not agree with CBD, ICAS, and NSB's statement. As stated in the MMPA, Level B harassment is defined as any act of                           ( print page 49427)                        pursuit, torment, or annoyance which “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.” Activities that affect marine mammal behavior briefly but not cause disruption of behavioral patterns are not considered “takes.”                

                    In addition, in regard to impacts to marine mammal behaviors, distance is not the only factor that counts. The received levels at which marine mammals are affected are related to a number of factors including source levels, distances, and acoustic propagation pathways. The particular example CBD brought up regarding the seismic surveys by the National Science Foundation used airgun arrays with total discharge volume of 2,840 in3                    , while the proposed CPAI shallow hazard and site clearance survey would only use an airgun array with total discharge volume of 40 in3                    . The different source levels determine the ensonified zone where marine mammals, including beluga whales, would be impacted.                

*Comment 19:*                     The ICAS points out that when calculating the estimated take number, CPAI used the equation of multiplying the average density of species by the length of trackline shots (in km) by twice of the distance of transmission loss to 160 dB. The ICAS states that such calculation did not include marine mammal takes within the semi-circular areas defined by the safety radii that would bound the start and end-points of seismic surveying. The ICAS states that to account for this discrepancy, the above equation should be supplemented with the semi-circular areas.                

*Response:*                     Comment noted. Although it is customary to include the semi-circular areas defined by the safety radii that would bound the start and end-points of seismic surveying, the 160-dB distance is very short due to the overall low intensity of the acoustic sources. Therefore, the ensonified area within the bounded semi-circular areas is very small (8 km2                    , or 0.045 percent of the total ensonified area) when compared to the total ensonified area even without the semi-circular areas (17,649 km2                    ). A recalculation of the estimated takes including the semi-circular areas did not show a difference from the original calculation.                

*Comment 20:*                     The CBD, ICAS, and NSB state that NMFS has no idea of the actual population status of several of the species subject to the proposed IHA. For example, in the most recent Stock Assessment Reports (SARs) prepared pursuant to the MMPA, NMFS acknowledges it has no accurate information on the status of ribbon, spotted, bearded, and ringed seals. CBD and NSB both indicate that without these data, NMFS cannot conclude that surveys which will harass untold numbers of individuals of each species would have no more than a “negligible impact” on the stocks.                

*Response:*                     As required by the MMPA implementing regulations at 50 CFR 216.102(a), NMFS has used the best scientific information available in making its determinations required under the MMPA. The Alaska SAR provides population estimates based on past survey work conducted in the region, and the SAR shows that based on the most recent information, all of these Alaska stocks of ice seal species have robust populations. The proposed survey by CPAI is not expected to have adverse impacts on ice seals. The activity will last for approximately 30-45 days in the open-water environment of the Chukchi Sea, where bearded and spotted seals are found only occasionally.                

In addition, it is expected that approximately 1,379 ringed and 376 bearded seals would be affected by Level B behavioral harassment as a result of the proposed shallow hazard and site clearance surveys, respectively, and that these take numbers represent 0.55 and 0.15 percent of the Alaska stocks of ringed and bearded seal populations within the Chukchi Sea, respectively. Although spotted and ribbon seals could also be taken by Level B behavioral harassment as a result of the proposed marine surveys in the Chukchi Sea, the probability of take is very low since their presence is very rare within the proposed project area. Nonetheless, NMFS believes their take numbers would be much lower as compared to those marine mammals whose take numbers were calculated.

*Comment 21:*                     Citing research on long term adverse effects to whales and dolphins from whale watching activities (Trites and Bain, 2000; Bain, 2002; Lusseau                     *et al.*, 2006), Dr. Bain states that Level B behavioral harassment could be the primary threat to cetacean populations.                

*Response:*                     Although NMFS agrees that long-term, persistent, and chronic exposure to Level B harassment could have a profound and significant impact on marine mammal populations, such as described in the references cited by Dr. Bain, however, those examples do not reflect the impacts of seismic surveys to marine mammals for the proposed CPAI project. First, whale watching vessels are intentionally targeting and making close approaches to cetacean species so the tourists onboard can have a better view of the animals. Some of these whale/dolphin watching examples cited by Dr. Bain occurred in the coastal waters of the Northwest Pacific between April and October and for extended periods of time (“[r]ecreational and scientific whale watchers were active by around 6 a.m., and some commercial whale watching continued until around sunset.”) Thus multiple vessels have been documented to be in relatively close proximity to whales for about 12 hours a day, six months a year, not counting some “out of season” whale watching activities and after dark commercial filming efforts. In addition, noise exposures to whales and dolphins from whale watching vessels are probably significant due to the vessels' proximity to the animals. To the contrary, the proposed 2008 open water shallow hazard and site clearance surveys, along with other potential four seismic activities and existing industrial operations in the Chukchi and Beaufort Seas, do not intentionally approaching marine mammals in the project areas. The two areas situate in a much larger Arctic Ocean Basin which is far away from most human impacts. Therefore, the adverse effects from each activity are remote and spread farther apart, as analyzed in the MMS 2006 PEA and draft EIS. The proposed seismic activities would only be conducted between August and October for 30-45 days, weather permitting. In addition, although studies and monitoring reports from previous seismic surveys have detected Level B harassment of marine mammals, such as avoidance of certain areas by bowhead and beluga whales during the airgun firing, no evidence suggests that such behavioral modification is biologically significant or non-negligible (Malme                     *et al.*, 1986; 1988; Richardson                     *et al.*, 1987; 1999; Miller                     *et al.*, 1999; 2005), as compared to those exposed by chronic whale watching vessels cited by Dr. Bain. Therefore, NMFS believes that potential impacts to marine mammals in the Arctic by shallow hazard and site clearance surveys would be limited to Level B harassment only, and due to the limited scale and remoteness of the projects in relation to a large area, such adverse effects would not accumulate to the point where biologically significant effects would realized.                

*Comment 22:*                     Dr. Bain states that changes in behavior resulting from noise exposure could lead to indirect injury in marine mammals in the wild. He presented several examples to suggest that marine mammals repeatedly                           ( print page 49428)                        exposed to Level B behavioral harassment could result in Level A takes: (1) Gas bubble lesions in beaked whales due to acoustically mediated bubble growth or rapid ascent by animals after deep diving; (2) a minke whale and harbor porpoises were observed traveling at high speed during exposure to mid-frequency sonar in Haro Strait in 2003, and that exhaustion from rapid flight could lead to heart or other muscle damage, which could cause mortality; (3) citing MMS' (2004) Environmental Assessment on Proposed Oil and Gas Lease Sale 195 in the Beaufort Sea Planning Area (OCS EIS/EA MMS 2004-028) that feeding requires a prey density of 800 mg/m3 and his own observation, Dr. Bain is concerned displacement from high productive feeding areas would negatively affect individual whales, and that small cetaceans such as harbor porpoises would face a risk of death if they are unable to feed for periods as short as 48-72 hours; (4) individual killer whales have been observed splitting their pod when frightened by sonar, and that other killer whales' separation from their social units has resulted in death; (5) TTS may lead to harm as a minke whale was nearly struck by a research vessel in the area where one had been observed fleeing mid-frequency sonar; and (6) impaired auditory ability may increase predation as white-sided dolphins were attacked by killer whales due to the noise of the research vessel caused the approach of killer whales undetected by the dolphins.                

*Response:*                     NMFS agrees that it is possible that changes in behavior or auditory masking resulting from noise exposure could lead to injury in marine mammals under certain circumstances in the world, such as those examples/hypotheses raised by Dr. Bain. However, it is not likely that received sound pressure levels (SPLs) from the shallow hazard and site clearance surveys would drastically cause changes in behavior or auditory masking in marine mammals in the vicinity of the proposed action area. First, marine mammals in the aforementioned examples and hypotheses were exposed to high levels of non-pulse intermittent sounds such as the military sonar, which has been shown to cause flight activities (e.g., Haro Strait killer whales); and continuous sounds such as the vessel, which could cause auditory masking when animals are closer to the source. The sources produced by the acoustic equipment and airguns for the proposed shallow hazard and site clearance surveys are impulse sounds used in seismic profiling, bathymetry, and seafloor imaging. Unlike military sonar, seismic pulses have an extremely short duration (tens to hundreds milliseconds), and relatively long intervals (several seconds) between pulses. Therefore, the sound energy levels from these acoustic equipment and small airguns are far lower in a given time period. Second, the intervals between each short pulse would allow the animals to detect any biologically significant signals, and thus avoid or prevent auditory masking. In addition, NMFS requires mitigation measures to ramp up acoustic sources at a rate of no more than 6 dB every 5 minutes. This ramp up would prevent marine mammals from being exposed to high level noises without warning, thereby eliminating the possibility that animals would dramatically alter their behavior (i.e. from a “startle” reaction). NMFS also believes that long-term displacement of marine mammals from a feeding area is not likely because the seismic vessel is constantly moving, and the maximum 160-dB ensonified radius is about 4 km, which would make an ensonified zone of approximately 50 km2 at any given moment, which constitutes a very small portion of the Chukchi Sea. In reality, NMFS expects the 160-dB ensonified zone to be smaller due to absorption and attenuation of acoustic energy in the water column.                

*Comment 23:*                     Citing that the difference between takes by subsistence harvest and potential biological removal (PBR) of the Western Arctic stock bowhead whales is about 28 individuals whales, or less than 0.3 percent of the population, Dr. Bain is concerned that the cumulative effects of multiple seismic surveys would not need to be very large to push takes over PBR for bowheads.                

*Response:*                     NMFS does not agree with Dr. Bain's assessment. None of the five proposed 2008 open water Arctic seismic surveys and shallow hazard and site clearance surveys is expected to result in any Level A harassment (i.e., injury) or mortality. As analyzed in the NMFS 2008 supplemental environmental assessment (SEA) for the issuance of five Arctic seismic surveys and shallow hazard and site clearance surveys, all incidental takes of marine mammals are expected to be Level B behavioral harassment (NMFS, 2008). Therefore, no PBR would be applied for the proposed CPAI seismic activities and other 2008 seismic activities in the Chukchi and Beaufort Seas.                

*Comment 24:*                     Citing MMS 2006 Programmatic Environmental Assessment (MMS 2006 PEA) and the MMS 2007 draft Programmatic Environmental Impact Statement (DEIS) for seismic surveys in the Arctic Ocean, Dr. Bain states that he supports the mitigation measures established in these documents that no more than 12 cow/calf pairs and aggregation of feeding or resting bowheads are within the area to be ensonified by 120 dB and 160 dB, respectively. The CBD also states that the monitoring of a 120 dB safety zone for bowhead cow/calf pairs and monitoring of a 160 dB safety zone for large groups of bowhead or gray whales (> 12 individuals) were required by NMFS in 2006 and were practicable. The CBD states that the failure to require such conditions, or at least analyze it, violates the MMPA. Dr. Bain presumes that these numbers (using 120 and 160 dBs) reflect the difference between takes allocated to hunters and the PBR for the stock. Dr. Bain further suggests that this number be applied to all seismic activities combined, not individual seismic surveys, thus, if four seismic surveys occur concurrently, no single survey should be allowed to affect the migration of more than 3 cow/calf pairs or 3 aggregation of feeding or resting bowhead whales.                

*Response:*                     First, the additional mitigation measures in the MMS 2006 PEA and the MMS 2007 draft PEIS, as well as in the 2007 NMFS SEA for the issuance of an IHA to Shell Offshore Inc. for its open water seismic surveys conducted in the Chukchi and Beaufort Seas in 2007, establish safety (shut-down) zones of 120 dB re 1 microPa for an aggregation of four or more bowhead cow/calf pairs and 160 dB re 1 microPa for an aggregation of 12 or more bowhead or gray whales, not 12 cow/calf pairs as Dr. Bain states in his comment. The rationale for this cautious and conservative approach when addressing the 120-dB and 160-dB safety zones is clearly stated in the MMS 2006 PEA. These additional mitigation and monitoring measures were identified through the analyses to further reduce the potential for adverse environmental impacts and, depending on the scope of seismic-survey activities, could be adopted as requirements for seismic-survey-related marine mammal incidental take authorizations. With respect to CBD's concern that these measures were “practicable” in 2006, NMFS has re-evaluated the practicability of requiring aerial monitoring to the 120-dB isopleth in the Chukchi. NMFS has determined that it is not practicable to conduct aerial monitoring to the 120-dB isopleth because aerial surveys have currently been determined to be impracticable                           ( print page 49429)                        due to lack of adequate landing facilities, the prevalence of fog and other inclement weather in that area, thereby resulting in safety concerns. Additionally, these conditions are analyzed in NMFS' 2008 SEA. These numbers have nothing to do with the PBR of the bowhead whale stock, as assumed by Dr. Bain. As discussed in FR Notice of Proposed IHA, the proposed 2008 Arctic seismic surveys and shallow hazard and site clearance surveys are not expected to result in Level A harassment (injury) or mortality.                

In addition, Dr. Bain's suggestion of “breaking up” the aggregated takes of bowheads into small subsets that can be “allocated” to each seismic survey is based on his assumption that these numbers were set by PBR. NMFS does not support this suggestion because it has no scientific support other than assumption. The safety zones of 120-dB for four or more cow/calf pairs and 160-dB for an aggregation of 12 bowhead or gray whales are based on the biology of the bowhead and gray whales as analyzed in the MMS 2007 draft PEIS.

The threshold of four or more fall-migrating bowhead whale cow/calf pairs was set based on the following: (a) cow/calf pairs are identified as the most vulnerable portion of the population and disruption of their biologically significant behaviors or their avoidance of important habitats is more likely to lead to population level impacts; (b) mitigation measures for this portion of the population should be cautiously developed to ensure that takings are at the lowest practicable level and that significance is avoided; (c) bowhead whale cow/calf pairs migrate in groupings or pulses and the observed presence of cow/calf pairs by surveys generally indicates that additional cow/calf pairs are present but unseen; (d) using professional judgment, NMFS and MMS have determined that the presence of four or more cow/calf pairs (as observed during surveys) indicates that enough cow/calf pairs are likely present (but some unseen) in the area in numbers equal to or greater than 12 animals; and (e) the potential for significance to occur therefore increases when four or more bowhead whale cow/calf pairs are observed (MMS, 2007).

The threshold of an aggregation of 12 or more bowhead or gray whales is based on the following premises: (a) whales aggregate in order to communicate and perform “biologically significant” behaviors (as defined by NRC, 2005), such as feeding, resting, socializing, mating, and calving; (b) aggregations of animals can also indicate an area of preferred habitat and locations where biologically significant behaviors are likely occurring; (c) disruptions of these biologically significant behaviors and important habitats have a greater potential to lead to population level effects (i.e., result in limiting reproductive potential or recruiting success, impeding important mother/calf bonding); (d) protective measures should be designed to reduce the potential for disruption of biologically significant behaviors or help ensure whales do not avoid important key habitat areas (and thus potentially negate a negligible impact finding under the MMPA); and (e) standard scientific acceptance that the presence of observed whales (i.e., at the surface) during monitoring surveys indicates that additional whales are also present in the area but non-detectable (i.e., below the surface) (MMS, 2007).

*Comment 25:*                     Dr. Bain is concerned that the North Pacific right whale is excluded from consideration for the proposed seismic activity in the Chukchi Sea. Citing Nowacek                     *et al.*                     (2004), Dr. Bain further states that the [North] Atlantic right whale is less easily disturbed [than the North Pacific right whale], is known to be affected by received levels below 135 dB.                

*Response:*                     NMFS does not agree with Dr. Bain and believes his concern is unwarranted. The North Pacific right whales are found in the northern part of the Pacific, such as the Bering Sea and the Gulf of Alaska (Moore                     *et al.*; 2000; 2002; LeDuc                     *et al.*, 2001; Waite                     *et al.*, 2003; Mellinger                     *et al.*, 2004; Wade                     *et al.*, 2006). They do not enter Chukchi Sea in the Arctic Ocean, where the proposed seismic activity is planned. In addition, NMFS is not able to verify Dr. Bain's statement that the North Atlantic right whale is less easily disturbed than the North Pacific right whale, since he did not provide a supporting reference.                

*Comment 26:*                     Dr. Bain is concerned that many species are sedentary, territorial, or have strong tendencies toward site fidelity, and that these species are unlikely to move away from a noise source. In addition, Dr. Bain is concerned that many predators are used to experiencing pain during feeding, and hence tolerate pain [from being exposed to loud noise] rather than abandoning their prey (e.g., many mammals involved in fishery-interactions).                

*Response:*                     First, the monitoring and mitigation measures described in this document and implemented for the proposed open water seismic activity would prevent any marine mammals from being exposed to received levels that could cause onset of injury (180 dB re 1 microPa for cetaceans and 190 dB re 1 microPa for pinnipeds). Second, there are no sedentary marine mammals. The proposed seismic activity is fundamentally different from commercial fisheries activity in which the appearance of a seismic vessel does not reinforce the marine mammal with food or prey, therefore, it is unlikely that predatory marine mammals would approach the seismic vessel or acoustic source while searching for prey. Even if a marine mammal happens to be in close vicinity of the vessel or source, monitoring and mitigation measures will required the crew to power-down or shut-down the acoustic sources so that the animal will not be affected by Level A harassment.                

*Comment 27:*                     Dr. Bain comments on NMFS' and CPAI's method of calculating estimated take numbers of marine mammals by multiplying the “strip width” by the length of the survey, and states that “[f]or bowheads, some studies showed behavioral changes in nearly all whales out to 20 km, and in many cases to at least 30 km.” Dr. Bain further states that “belugas and bowheads are known to be affected at 10-20 km or more.” At such, Dr. Bain observes that the ramp-up procedures would not be effective as it would take about 5 hours for the bowheads [near the source] to move to a distance of 30 km, and marine mammal monitoring over a distance of 20 km is very difficult.                

*Response:*                     First, the estimated takes of marine mammals were calculated by multiplying the expected average animal densities by the area of ensonification for the 160 dB re 1 microPa (rms) isopleth for marine mammals. The area of ensonification was determined by multiplying the total proposed trackline (5,300 km or 3,294 mi) times 2 (both sides of the trackline) times the distance to the 160-dB isopleth (not “strip width,” a term usually used in the population survey, as stated by Dr. Bain in his comment).                

                    NMFS cannot verify Dr. Bain's statement that “some studies showed behavioral changes in nearly all whales out to 20 km, and in many cases to at least 30 km” and that “belugas and bowheads are known to be affected at 10-20 km or more,” since he did not provide any supporting references. Neither did Dr. Bain provide the source levels and displacement volumes of the airgun arrays in which these studies were conducted, nor the severity of the behavioral changes by the whales. Nevertheless, it is important to understand that the distance from the seismic sources where bowheads or other marine mammals can be affected depends on the source levels of the                           ( print page 49430)                        airgun arrays, which is also related to the size, or displacement volume of the airgun array. It is possible that if a large airgun array was used in the seismic survey, the received level at 20 to 30 km distance could still be high enough to cause behavioral changes (or behavioral harassment) by the bowhead whales. However, for the proposed shallow hazard and site clearance surveys, the source levels of the airgun array and other acoustic equipment are relatively low (about 214 dB re 1 microPa for the GeoChirp II, the loudest acoustic equipment planed to be used), and that the modeled distance to the 160-dB isopleths is estimated at 1,665 m (5,463 ft). Please see Number of Marine Mammals Estimated to be Taken section below for a detailed description of the calculation.                

As far as mitigation measures are concerned, NMFS expects that the distance from the source to the safety zone for cetaceans is approximately 115 m (377 ft), where the received level is at 180 dB re 1 microPa, which is a small enough area to be effectively monitored by NMFS-approved marine mammal monitors (MMOs). Furthermore, no seismic surveys, ramp up included, will commence if there is a marine mammal within the safety zone.

*Comment 28:*                     Citing the 90-day monitoring report for the SOI 2007 open water seismic activities, the NVPH is concerned that the shallow hazard and site clearance surveys could exclude nearly all migrating bowhead whales from waters within 20 km or more of the survey vessel, since the 120-dB isopleth extends over 25 km. The NVPH states that similar displacement of beluga whales at a large distance is also possible.                

*Response:*                     NMFS does not agree with NVPH's assessment regarding the potential acoustic impacts to bowhead and beluga whales. First, as discussed in                     *Response*                     to                     *Comment 4*, although it is possible that marine mammals could react to any sound levels detectable above the ambient noise level within the animals' respective frequency response range, this does not mean that such animals are taken by Level B harassment (see definition of Level B harassment above). The degree of reaction which constitutes a “take,” i.e., a reaction deemed to be biologically significant that could potentially disrupt the migration, breathing, nursing, breeding, feeding, or sheltering, etc. of a marine mammal is complex and context specific, and it depends on several variables in addition to the received level of the sound by the animals. In many cases, bowhead or beluga whales that are exposed to 120 dB re 1 microPa or higher do not exhibit noticeable behavioral changes (e.g., Malme                     *et al.*, 1984; Richardson                     *et al.*, 1986; 1999; Miller                     *et al.*, 2005). Second, although migrating bowhead whales have been seen to be excluded from entering areas with seismic sound levels at approximately 120 dB re 1 microPa in the Beaufort Sea (Richardson                     *et al.*, 1999), NMFS believes this was due to the narrower migratory route in the Beaufort Sea where the whales migration was impeded due to the seismic noise. However, the migratory route of bowhead whales is much wider in the Chukchi Sea. The wider migratory route allows bowhead whales to go around the ensonified zone during their migration, instead of being impeded by the sound. In addition, since the source levels from the shallow hazard and site clearance survey are relatively low (214 dB re 1 microPa for the source of the loudest acoustic equipment), the ensonified zone would also be relatively small. If any deflection were to occur, NMFS does not believe it would be biologically significant. Therefore, NMFS does not believe that bowhead and beluga whales would be displaced when exposed to received level from seismic airguns at 120 dB re 1 microPa.                

*Comment 29:*                     The NSB states CPAI used the density information to estimate the number of belugas they may encounter and take during the seismic operations, based on 2006 and 2007 vessel based survey, was not appropriate, since these data were collected in the same season when seismic operations were occurring and belugas appear to be sensitive to industrial sounds. The NSB recommends that the Brueggerman                     *et al.*                     (1990; 1991; 1992) observations be used to calculate the beluga density. The NSB further states that if CPAI conducts surveys into October or November, it would also encounter belugas from the Beaufort Sea stock as the animals are migrating toward wintering areas. Therefore, it is highly unlikely that only 10 belugas would be disturbed.                

*Response:*                     NMFS agrees with the NSB's assessment regarding the uncertainty of beluga density in the vicinity of the proposed seismic operation area. Although density estimate data for marine mammals in the Arctic Ocean are available, NMFS typically uses the most recent data because they are deemed to be reliable. In this case, the 2006 and 2007 beluga whale monitoring data provide the most recent scientific information on the distribution of these animals, while the Brueggerman                     *et al.*                     (1990; 1991; 1992) data are 16-18 years old. In addition, the NSB did not provide the full citation of the Brueggerman                     *et al.*                     references for NMFS to verify and compare. However, NMFS also recognizes that satellite tagging efforts directed at the eastern Chukchi stock of beluga whales showed that whales tagged in the eastern Chukchi in summer traveled 1,100 km (684 mi) north of the Alaska coastline and to the Canadian Beaufort Sea within 3 months of tagging (Suydam                     *et al.*, 2001), indicating significant stock overlap with the Beaufort Sea stock of beluga whales. For these reasons, NMFS could not provide a take estimate for beluga whales for both populations. Nevertheless, recent data from the LGL Report (LGL, 2008), which was based on marine mammal monitoring during the 2007 Shell and CPAI seismic surveys, showed that beluga whale distribution in the proposed seismic area in the Chukchi Sea is very low. Therefore, NMFS believes that only a small undetermined number of beluga whales would be affected by Level B harassment as a result of the proposed CPAI shallow hazard and site clearance surveys.                

### Subsistence Uses

*Comment 30:*                     NVPH questions whether NMFS's assessment of the impacts to subsistence was based on the “best available scientific evidence” and whether NMFS has made any effort to discern whether seismic surveying activities in the Chukchi Sea in 2006 or 2007 had an adverse impact on the availability of any or all seal and whale species for subsistence uses.                

*Response:*                     In making its final determination of whether the proposed shallow hazard and site clearance surveys would have unmitigable impacts to subsistence use of marine mammal populations in the affected area, NMFS relies upon the best available scientific information to make its MMPA determinations. In this case, NMFS has reviewed the 90-day marine mammal monitoring and mitigation reports for the 2006 and 2007 open water seismic survey and shallow hazard and site clearance survey conducted by Shell Offshore, Inc. (SOI), ConocoPhillips Alaska, Inc., and GXTechnology in 2006 and by SOI in 2007 (Ireland                     *et al.*, 2007a; 2007b; Patterson                     *et al.*, 2007; Funk                     *et al.*, 2007; 2008). These monitoring reports point out that the impacts to marine mammals as a result of the 2006 and 2007 Arctic seismic activities were negligible. In addition, actual take of marine mammals by Level B harassment was generally lower than expected due to the implementation of monitoring and mitigation measures. No marine                           ( print page 49431)                        mammals were observed to have suffered injuries or death as a result of the seismic surveys and none were suspected. In addition, information presented by the oil and gas industry and independent researchers who conducted marine mammal monitoring at the 2007 and 2008 Arctic Open Water Scientific Meetings was also taken into consideration.                

*Comment 31:*                     NVPH states that NMFS failed to provide the substantive analysis to support any meaningful finding regarding the possible effect of CPAI's activities on the availability of beluga whales, seals, and bowhead whales for subsistence uses by coastal communities along the Chukchi Sea or the effectiveness of mitigation measures to eliminate such impacts. The NVPH further states that the Chukchi Sea and the adjoining coast existed as a relatively pristine ocean environment, free of industrial operations that would disturb bowhead and beluga whales and seals with their availability for subsistence uses. Therefore, NVPH states that even a slight interference in the availability of these species to communities on the Chukchi Sea would constitute an unmitigable adverse impact to their overall availability for subsistence uses.                

*Response:*                     NMFS does not agree with NVPH's statement. The FR Notice of Proposed IHA provided a detailed analysis regarding the possible effect of seismic surveys and underwater sound on marine mammals in the planned action area. This analysis prompted NMFS to make a preliminarily determination that the impact of conducting the shallow hazard and site clearance surveys in Chukchi Sea may result, at worst, in a temporary modification in behavior of small numbers of marine mammals.                

NMFS agrees that the Chukchi Sea and the adjoining coast existed as a relatively pristine ocean environment that was free of industrial operations. However, NMFS does not agree with NVPH's assessment that within this environment, a slight interference in the availability of these species to communities on the Chukchi Sea would constitute an unmitigable adverse impact for subsistence uses of these species. The proposed shallow hazard and site clearance surveys proposed by CPAI would only occur in a small area within the much larger Chukchi Sea basin for a brief period of 30-45 days. It would also occur far offshore, approximately 70 miles, outside the area in which harvest traditionally occurs. In addition, because CPAI's seismic surveys will occur during the late summer and fall (after many of the Chukchi Sea communities have harvested sizeable portions of their marine mammal quota), NMFS does not believe that CPAI's activities are likely to reduce the availability of the affected species to a level insufficient for a harvest to meet its needs. NMFS does not expect subsistence users to be directly displaced by the seismic surveys because subsistence users typically do not travel this far offshore to harvest marine mammals. Next, because of the significant distance offshore and the lack of hunting in these areas, there is no expectation that any physical barriers would exist between marine mammals and subsistence users. Furthermore, mitigation and monitoring measures required for the seismic activities are expected to reduce all potential impacts to negligible levels to marine mammals and their habitat. Finally, CPAI will be working with Native communities in the affected region to ensure that seismic operations do not result in an unmitigable adverse impact on the availability of marine mammals to subsistence uses by the Native communities in and around the Chukchi Sea.

*Comment 32:*                     The CBD, NVPH, ICAS, and NSB state that the MMPA requires that any incidental take authorized will not have “an unmitigable adverse impact on the availability of such species or stock for taking for subsistence uses” by Alaska Natives. The NVPH is concerned that CPAI intends to conduct surveys within just a few miles of the village of Wainwright, and that it also plans to conduct surveys near the north end of Kasegaluk Lagoon, which is an important subsistence use area for residents of Point Lay, and contains the largest concentration of spotted seals in Alaska. The NSB is also concerned about impacts to subsistence hunts of marine mammals in the summer: notably beluga hunts at Point Lay and Wainwright, and walrus and bearded seal hunts in all of the villages of the Alaska Bering and Chukchi Seas. The NSB states that the summer beluga whale hunt at Point Lay extends into July, the hunt in Wainwright extends into August, and Point Hope and Wainwright hunt bowhead whales in the fall and these hunts may be adversely affected. Additionally, CBD notes they are aware that the NVPH, a federally recognized tribal government, has submitted comments opposing the proposed take authorizations due to impacts on subsistence, and along with many community members has commented on myriad other related agency documents that have direct bearing on these take authorization such as the Chukchi Sea Sale 193, MMS Five-Year Plan, and the DPEIS. Similarly, the NSB, the AEWC, and REDOIL have all filed challenges in federal court and/or the IBLA challenging offshore activities due to impacts on the subsistence hunt of bowheads and other species. In light of the positions of these communities and organizations, the CBD does not think that NMFS can lawfully make the findings required under the MMPA for approving CPAI's proposed IHA.                

*Response:*                     NMFS does not agree with CBD, NVPH, ICAS, and NSB's statement. The CPAI's shallow hazard and site clearance survey will not occur in the coast of the Alaska North Slope. As stated in the FR Notice of Proposed IHA, the two areas for the proposed CPAI shallow hazard and site clearance surveys would be conducted about 111 km (69 mi) off the Alaska coast, generally west from the village of Wainwright. Therefore, NVPH's concern that the proposed seismic activities would be conducted just miles off the coast is unwarranted.                

 Although CPAI plans to conduct its shallow hazard and site clearance survey in August, it is likely that the surveys would not start until mid-August, thus missing the summer beluga hunt at Point Lay and most in Wainwright. In addition, as mentioned earlier, the proposed shallow hazard and site clearance survey would be conducted 69 miles off the coast and would therefore not overlap with the subsistence harvest of beluga whales and bearded seals. The subsistence hunt of walruses was reviewed by the FWS since it is a species under the FWS jurisdiction. An LOA was issued by the FWS for the take of walruses incidental to CPAI's proposed seismic surveys. Finally, the IHA issued to CPAI includes specific mitigation measures that would prevent any unmitigable impacts to subsistence use of marine mammals from the proposed seismic activities. Please refer to the Mitigation Section of this document for detailed information.

*Comment 33:*                     The AEWC states that CPAI has not communicated its intentions regarding the signing of Conflict Avoidance Agreement (CAA) with the AEWC, and that it understands that CPAI would not agree to the 2008 CAA. Therefore, AEWC observes that to issue an IHA to a company that would not voluntarily agree to the terms of the CAA, NMFS must limit its authorization to times and locations that would ensure they company's compliance with the mitigation measures set forth in the CAA—no more than two simultaneous geophysical activities in each of the Beaufort and Chukchi Seas. The AEWC                           ( print page 49432)                        further states that it would not oppose an IHA issued to CPAI containing these limitations and the other requirements and recommendations provided by the NSB in its comments. Finally, the AEWC states that it will oppose any IHA issued by NMFS that does not contain mitigation measures identical to those set forth in the 2008 CAA.                

*Response:*                     Comment noted. Under sections 101(a)(5)(A) and (D) of the MMPA (16 U.S.C. 1361*et seq.*), an IHA or LOA would be granted to U.S. citizens who engage in a specified activity (other than commercial fishing) within a specified geographical region if NMFS finds that the taking of marine mammals will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for certain subsistence uses, and if the permissible methods of taking and requirements pertaining to the mitigation, monitoring and reporting of such takings are set forth. In other words, no marine mammal take authorizations may be issued if NMFS has reason to believe that the proposed exploration or development activities would not have an unmitigable adverse impact on the availability of marine mammal species or stock(s) for Alaskan native subsistence uses. Although Federal laws do not require consultation with the native coastal communities until after offshore exploration and development plans have been finalized, permitted, and authorized, pre-permitting consultations between the oil and gas industry and the Alaskan coastal native communities are considered by NMFS when the agency makes a determination whether such activities would have an unmitigable adverse impact on the availability of marine mammal species or stock(s) for subsistence uses. For the proposed shallow hazard and site clearance survey, CPAI has conducted POC meetings for its seismic operations in the Chukchi Sea in the communities and villages of Kivalina, Kotzebue, Wainwright, Barrow, Point Lay, and Point Hope.                

CPAI has not signed the 2008 CAA with Alaska Natives and has informed NMFS that it does not intend to do so. NMFS has scrutinized all of the documents submitted by CPAI (e.g., IHA application, Plan of Cooperation and other correspondence to NMFS and affected stakeholders) and documents submitted by other affected stakeholders and concluded that harassment of marine mammals incidental to CPAI's activities will not have an unmitigable adverse impact on the availability of marine mammals for taking for subsistence uses. This finding was based in large part on NMFS' definition of “unmitigable adverse impact”, the proposed mitigation and monitoring measures, the 2008 CAA signed by other industry participants and Alaska Natives, the scope of activities proposed to be conducted, including time of year, location and presence of marine mammals in the project area, and CPAI's Plan of Cooperation.

                    As described in CPAI's IHA application, the seismic survey is proposed to be conducted approximately 70 miles off the Alaskan coast in the Chukchi Sea where very little subsistence harvest occurs. In addition, because CPAI's seismic surveys will occur during the late summer and fall (after many of the Chukchi Sea communities have harvested sizeable portions of their marine mammal quota), NMFS does not believe that CPAI's activities are likely to reduce the availability of the affected species to a level insufficient for a harvest to meet its needs. NMFS does not expect subsistence users to be directly displaced by the seismic surveys because subsistence users typically do not travel this far offshore to harvest marine mammals. Next, because of the significant distance offshore and the lack of hunting in these areas, there is no expectation that any physical barriers would exist between marine mammals and subsistence users. For bowhead whale subsistence hunting, recent history shows that Point Hope and Wainwright only hunt during the spring migration (Suydam                     *et al.*, 2005; Suydam and George, 2004). The village of Barrow hunts during the spring and fall migrations, taking most bowheads during the spring migration. The fall hunt occurs in open water from late August through October by Barrow, and whalers hunt mainly in the waters east and northeast of Point Barrow in the Beaufort Sea. Also, hunters prefer to take bowheads close to shore to avoid a long tow during which the meat can spoil. Beluga whales are hunted for subsistence at Barrow, Wainwright, Point Lay, and Point Hope, with the most taken by Point Lay (Fuller and George, 1997). Harvest at all of these villages generally occurs between April and July with most taken in April and May when pack-ice conditions deteriorate and leads open-up. Ringed, bearded, and spotted seals are hunted by all of the villages bordering the project area (Fuller and George, 1997). Ringed and bearded seals are hunted throughout the year, but most are taken in May, June, and July when ice breaks up and there is open water instead of the more difficult hunting of seals at holes and lairs. Spotted seals are only hunted in spring through summer. Therefore, the scheduling of the proposed shallow hazard and site clearance survey is expected to have minimum conflict between the industries and marine mammal harvests.                

Finally, in the event harvest activities do occur this far offshore, the required mitigation and monitoring measures are expected to reduce any adverse impacts on marine mammals for taking for subsistence uses to the extent practicable. These measures include, but are not limited to, the 180 dB and 190 dB safety (shut-down/power-down) zones; a requirement to monitor the 160 dB isopleths for aggregations of 12 or more non-migratory balaenidae whales and when necessary shut-down seismic airguns; maintaining a distance of at least 15 miles from other operating seismic vessels; reducing vessel speed when a vessel is within 300 yards of whales to avoid a collision; utilizing communication centers to avoid any conflict with subsistence hunting activities; and the use of marine mammal observers. Many of these requirements are consistent with the measures contained in the 2008 CAA entered into between other industry participants who operate in the Chukchi Sea and Alaska Natives.

NMFS does not agree with AEWC's recommendation to limit no more than two simultaneous geophysical activities in each of the Beaufort and Chukchi Seas. As analyzed in detail in the MMS 2006 PEA and NMFS 2008 SEA, a total of four simultaneous geographical/seismic activities can be conducted in each of the Beaufort and Chukchi Seas without significant impacts to the human environment. A similar finding was made for the proposed 2008 CPAI shallow hazard and site clearance survey in the Chukchi Sea.

*Comment 34:*                     NVPH states that it noted that CPAI proposes to mitigate impacts to subsistence activities via measures developed through a Plan of Cooperation (POC) with the AEWC and a variety of meetings and consultations. The NVPH states that there is no guarantee that these processes would result in enforceable limits that ensure CPAI's activities have no unmitigable adverse impact on the availability of seals and whales for subsistence purposes. The NVPH further states that by relying on these processes without ensuring that they produce a meaningful outcome, NMFS has effectively deferred its determination whether CPAI's activities would have an unmitigable adverse impact on the availability of                           ( print page 49433)                        seals and whales for subsistence uses by communities along the Beaufort Sea until after a POC has been developed.                

*Response:*                     NMFS does not agree with NVPH's assessment. First, the proposed CPAI shallow hazard and site clearance survey is planned in the Chukchi Sea, not the Beaufort Sea as NVPH stated in its comment. In order to make a determination that the proposed CPAI 2008 shallow hazard and site clearance surveys would not have a unmitigable adverse impact on the availability of marine mammal species or stocks for taking for subsistence uses in the proposed seismic area, NMFS carefully reviewed and analyzed the proposed seismic activities before making its determination (see Response to Comment 33). NMFS also reviewed other information presented in various documents, including but not limited to, the MMS 2006 PEA, the MMS 2007 draft PEIS, 2006 and 2007 Arctic seismic survey monitoring reports, and the 2008 CAA.                

*Comment 35:*                     NVPH states that NMFS failed to discuss a mandatory limit on the number of concurrent seismic and/or shallow hazard surveys in the Chukchi Sea. NVPH requests NMFS to prohibit the simultaneous operation of multiple vessels within the Chukchi Sea during the fall bowhead migration. NVPH further requests that NMFS require that no two vessels operate within 100 km (62 mi) of one another, because given the large size of the 120 dB zone, closer simultaneous operation would pose a real risk of disrupting the bowhead whale migration.                

*Response:*                     NMFS does not agree with NVPH's statement and request. First, the MMS 2006 PEA, which NMFS incorporated into its 2008 SEA, provided a thorough analysis on the maximum number of eight seismic activities that could occur in the Chukchi and Beaufort Seas. The analysis lead NMFS and MMS to conclude that up to a maximum of eight seismic surveys would not result in significant impacts to the quality of the human environment. In addition, NMFS' 2008 SEA, which analyzed the effect of multiple seismic surveys also lead NMFS to conclude that the CPAI survey would not result in a significant impacts.                

NVPH has not provided NMFS with any data to support its argument that multiple seismic vessels should not be permitted in the Chukchi Sea or that no more than 2 vessels be allowed to operate within 100 km (62 mi) of one another. The 100 km (62 mi) separating distance for the 120 dB zone between vessels is not scientifically supportable. The distance where the received level reaches 120 dB re 1 microPa is dependent upon the source level and oceanographic conditions. For the same oceanographic conditions, the higher the source level, the longer the distance where the received level would reach 120 dB. Therefore, at this time, there is no basis upon which to limit effort to no more than 2 vessels within 100 km of one another.

### Mitigation and Monitoring

*Comment 36:*                     Dr. Bain questions the effectiveness of marine mammal monitoring with only two MMOs on duty full time. Citing Forney and Barlow (1998) and Dahlheim and Towell (1994), Dr. Bain states that a common work schedule where consistent effort is required would be 40 minutes on, 40 minutes off, 40 minutes on, two hours off, three times a day. Dr. Bain suggests that an observation team of 12 MMOs would be required to cover a 24-hour period. Dr. Bain further states that the probability of detecting marine mammals would drop with increased distance from the vessel.                

*Response:*                     NMFS does not agree with Dr. Bain's assessment and suggestions regarding MMOs and marine mammal monitoring. NMFS reviewed the references (Dahlheim and Towell, 1994; Forney and Barlow, 1998) provided by Dr. Bain, and did not find any type of work schedules described. Unlike observers during marine mammal population surveys who are required to search the entire field for any marine mammals, the primary responsibility for MMOs is to monitor the safety zones, which in this case are 115 m (377 ft) radius for the 180-dB isopleth and 20 m (66 ft) radius for the 190-dB isopleth, and to ensure that proper mitigation measures (power-down or shut-down acoustic sources) are implemented if a marine mammal enters or is sighted within these safety zones. NMFS agrees that the detection probability of a marine mammal drops with increased distance from the ship. However, the occurrence of marine mammals outside the safety zones is not a big concern for marine mammal monitoring during the proposed seismic activity because it is presumed these animals would not be within a zone that could result in injury. Furthermore, MMOs would be on duty for 4 consecutive hours or less to reduce fatigue. In addition, all MMOs hired for the proposed seismic surveys must be NMFS-approved observers who are qualified to perform the required monitoring tasks. Therefore, NMFS believes that two MMOs are effective for marine mammal monitoring for CPAI's shallow hazard and site clearance surveys.                

*Comment 37:*                     Dr. Bain is concerned that many species that are capable of diving for more than 30 minutes could be missed during the monitoring.                

*Response:*                     NMFS agrees with Dr. Bain that monitoring for deep diving marine mammals it poses a challenge. However, within the proposed seismic survey area, there are no marine mammals that normally dive for more than 30 minutes. However, in the event that a marine would be missed during the initial pre-survey monitoring, ramp-up procedures will be followed when an acoustic source begins to operate, so the undetected animal(s) would have an opportunity to detect the sound as it increases gradually and move away from the source. Please refer to Monitoring and Mitigation Measures section below for a detailed description of these measures.                

*Comment 38:*                     NVPH is concerned that NMFS did not discuss the option of requiring CPAI to power down its airguns and other sound sources when aggregations of feeding, resting or socializing bowhead whales or gray whales are located within the 160 dB isopleth, and that NMFS fails to discuss the option of requiring CPAI to monitor the 120 dB isopleth for bowhead cow-calf pairs and to require CPAI to power down its sound sources when four or more cow-calf pairs are observed to be exposed to noises at or above 120 dB. NVPH requests that NMFS requires both of these mitigation measures. Citing Richardson's observation, NVPH further states that nearly all bowhead whales avoid seismic airguns at received levels as low as 107 dB, and requests NMFS to impose a safety zone for bowhead cow-calf pairs exposed to 107 dB or more. In addition, as NVPH observes that it would be impossible to monitor such a large area be ship-based observation, NVPH requests that such monitoring be conducted by aerial observation together with ship-based observers, for both of these safety zones.                

*Response:*                     In its final determination and the IHA issued to CPAI, NMFS requires CPAI to establish a 160-dB safety zone whenever an aggregation of 12 or more bowhead whales or gray whales are observed. If an aggregation of 12 or more bowhead or gray whales is observed within the 160-dB safety zone around the seismic activity, the seismic operation will not commence, or will shut down, until two consecutive vessel surveys indicate they are no longer present within the 160-dB safety zone of seismic-surveying operations.                

                    However, NMFS will not impose a requirement to conduct aerial monitoring of the 120-dB safety zone for the occurrence of four or more cow-calf                           ( print page 49434)                        pairs in the Chukchi Sea because it is not practicable. First, the 120-dB safety zone would require a safety zone of 20 km (12 mi) in radius, which is beyond the range for visual monitoring. The 120-dB ensonified zone is also too large to be monitored by chase boats. Second, aerial surveys are not required in the Chukchi Sea because they have currently been determined to be impracticable due to lack of adequate landing facilities, the prevalence of fog and other inclement weather in that area, thereby resulting in safety concerns.                

                    As far as the NVPH's statement that nearly all bowhead whales avoid seismic airguns at received levels as low as 107 dB, NMFS is not able verify NVPH's assessment because NVPH did not provide a reference to support its statement. A comprehensive review by Southall                     *et al.*                     (2007) on the potential acoustic impacts to low-frequency cetaceans (bowhead and other large whales) does not list any reference that shows these animals react to received levels under 110 dB re 1 microPa. Therefore, NMFS does not believe bowhead whales exposed to 107 dB would be taken by Level B behavioral harassment, and that imposing a safety zone of 107 dB is not appropriate.                

*Comment 39:*                     CPAI states that they are not able to ramp up the single source because they plan to use a low level sparker seismic tool for the geohazard surveys. CPAI requests that NMFS not require ramp-up procedures. CPAI indicates that they would still follow the following mitigation measures, including (1) vessel speed or course alteration; (2) shutdown procedures; (3) MMOs on the vessels; and (4) communication systems to stay in contact with villages and hunters to avoid conflict with subsistence activities.                

*Response:*                     With respect to CPAI's comment, NMFS has communicated with ASRC Energy Services (AES), which plans to conduct a similar shallow hazard and site clearance survey in the Chukchi Sea during the 2008 open water season and use essentially the same acoustic equipment CPAI listed in its IHA application. AES indicated that all of these Sparker acoustic systems can be ramped up. NMFS has also been informed by the U.S. Geological Survey and other contractors who use Sparker or similar acoustic systems that these acoustic devices have the capability to ramp up. Based upon this information and the technology identified in CPAI's application, there does not appear to be a legitimate reason for waiving the ramp up procedures because Sparker or similar acoustic systems are capable of ramp up and these devices are available for CPAI's use this season. In addition, ramping up is a standard mitigation measure for seismic surveys that introduce high level acoustic energy (over 200 dB re 1 microPa) into the water column, and is described in the MMS 2006 PEA, the MMS 2007 draft PEIS, and NMFS 2008 SEA for seismic surveys in the Arctic as a required mitigation measure under the preferred alternative. Furthermore, NMFS requires all IHA applicants that plan to conduct seismic surveys in the 2008 Arctic open-water season to ramp up their seismic sources as a mitigation measure. Therefore, NMFS cannot waive ramp-up requirement just for CPAI.                

After further discussion with CPAI, CPAI agreed that they will use a smaller sparker tool to initiate the survey and then transfer to the larger sparker. This process would be equivalent to a traditional ramp up requirement and would be an appropriate mitigation measure.

*Comment 40:*                     NVPH states that NMFS failed to provide for peer review of CPAI's proposed monitoring plans. It further states that the presentation provided by CPAI at the 2008 Open Water Scientific Meeting only gave very limited information and was unable to respond to even the most basic questions raised by attendees. NVPH requests NMFS to reject any suggestion that the meeting satisfied the peer review requirement. NVPH states that peer review by independent, objective reviewers remains necessary.                

*Response:*                     In order for the independent peer-review of Arctic area activity monitoring plans, it must be conducted in an open and timely process. Review by organizations, such as the National Academy of Sciences, would take at least a year to complete and would likely provide for an inflexible monitoring plan (e.g., any modifications would require reconvening the Committee). As a result, NMFS believes that independent peer-review of monitoring plans can be conducted via two means. First, the monitoring plans are made public and available for review by scientists and members of the public in addition to scientists from the NSB, NMFS, and the FWS. In accordance with the MMPA, the Marine Mammal Commission's Committee of Scientific Advisors reviews all IHA applications, including the monitoring plans. Second, monitoring plans and the results of previous monitoring measures are reviewed once or twice annually at public meetings held with the industry, the AEWC, the NSB, Federal agencies and the public. CPAI's mitigation and monitoring plan was reviewed by scientists and stakeholders at a meeting in Anchorage between April 14, 2008, and April 16, 2008, and by the public between May 23, 2008 (73 FR 30064) and June 23, 2008. NMFS believes that it has met the requirements of section 101(a)(5)(D) of the MMPA.                

*Comment 41:*                     The CBD, NSB, ICAS, and Dr. Bain state that during night-time and poor visibility condition, CPAI proposes essentially no limitations on operations, even though the likelihood of observers seeing marine mammals in such conditions is very low. The NSB requests NMFS to require CPAI to cese operations during darkness and inclement weather until another technique becomes available for observing safety zones under such conditions. The NSB further states that MMOs would not be able to measure Level B impacts because they would not be able to see far enough away from the vessel to observe the zones where Level B takes may occur.                

*Response:*                     The IHA issued to CPAI does not allow the start up of acoustic sources when the entire safety zones cannot be adequately monitored. However, as stated in the FR Notice of Proposed IHA, once the safety zones are visually established and that pre-survey monitoring has determined there are no marine mammals within the safety zones, seismic surveys can commence and continue into low visibility conditions. However, if for any reason the seismic sources are stopped during low visibility conditions, they are not to be restarted until the conditions are suitable for the marine mammal visual monitoring so that the safety zones can be reestablished. Nevertheless, ramping up of airguns and other seismic equipment during under normal visual conditions is expected to keep marine mammals from entering the established safety zones. In addition, NMFS also does not agree with NSB's assessment that the MMOs are not able to monitor the entire Level B zone. The 160-dB isopleth is estimated to be 1,665 m, which can reasonably be monitored from the source vessel with binoculars. Please refer to Monitoring and Mitigation Measures section below for a detailed description.                

*Comment 42:*                     The CBD and NSB state that NMFS and CPAI did not adequately consider the use of passive acoustic monitoring (PAM). While past IHAs have required PAM, this IHA completely ignores even discussing the possibility of using such monitoring.                

*Response:*                     NMFS disagrees. The MMPA has not established standards for                           ( print page 49435)                        monitoring requirements. The monitoring requirements proposed are to ensure that the taking will have a negligible impact on the species or stock(s) and will not have an unmitigable adverse impact on the availability of the species or stock(s) for subsistence uses. Monitoring measures are also used to reduce the level of takes to the lowest level practicable due to implementation of the mitigation measures.                

Monitoring measures for different projects are proposed on a case-by-case basis, and there is no “one size fits all” type of monitoring protocol. For the proposed shallow hazard and site clearance survey in the Chukchi Sea, the radius of the safety zone (115 m, or 377 ft) based on the 180 db re: 1 microPa isopleth is too small to allow accurate and effective passive acoustic monitoring. As the Joint Nature Conservation Committee (JNCC, 2004) stated that in practice the exclusion zone (safety zone) needs to be more than 500 m (1,640 ft) to allow for accurate passive acoustic monitoring (PAM). JNCC also noted that in many cases PAM is not as accurate as visual observation when determining range. NMFS believes that in the subject seismic survey projects, where the safety zone is as small as 115 m (377 ft), passive acoustic monitoring is not warranted. The presence of additional vessels for deploying PAM would only introduce more noise to the small area where the proposed projects are to occur.

### NEPA

*Comment 43:*                     NVPH, CBD, ICAS, and the NSB state that NMFS must prepare an Environmental Impact Statement (EIS) to evaluate CPAI's shallow hazard surveys, together with the other seismic and shallow hazard surveying activity proposed for the summer of 2008 in the Beaufort and Chukchi Seas.                

*Response:*                     NMFS prepared a Final SEA to analyze further the effects of CPAI's (and other companies) proposed open-water shallow hazard and site clearance survey activities for the 2008 season. NMFS has incorporated by reference the analyses contained in MMS 2006 Final PEA for Arctic OCS Seismic Surveys in the Beaufort and Chukchi Seas and has also relied in part on analyses contained in the MMS 2007 FEIS for the Chukchi Sea Lease Sale 193, the MMS 2003 FEIS for multiple lease sales, and the MMS 2007 DPEIS submitted for public comment on March 30, 2007.                

The 2006 PEA analyzed a broad scope of proposed seismic activities in the Arctic Ocean. In fact, the PEA assessed the effects of multiple, ongoing seismic surveys (up to 8 surveys) in the Beaufort and Chukchi Seas for the Arctic open water season. Although CPAI's proposed activity for this season was not explicitly identified in the 2006 PEA, the PEA did contemplate that future seismic activity, such as CPAI's could occur. NMFS believes the range of alternatives and environmental effects considered in the MMS 2006 PEA, combined with NMFS' SEA for the 2008 season are sufficient to meet the agency's NEPA responsibilities. In addition, the 2008 SEA includes new information obtained since the 2006 Final PEA was issued, including updated information on cumulative impacts. NMFS also includes a new section in the 2008 SEA, which provides a review of the 2006 and 2007 monitoring reports. As a result of our review and analysis, NMFS has determined that it was not necessary to prepare and issue an EIS for the issuance of an IHA to CPAI in 2008 for seismic activity in the Chukchi Sea but that preparation of an SEA and issuance of a Finding of No Significant Impact (FONSI) were sufficient under NEPA.

*Comment 44:*                     The NSB, NVPH, ICAS, and CBD state that NMFS appears to rely on the NEPA analysis in the DPEIS in clear violation of NEPA law. They state that NEPA requires agencies to prepare a draft EIS, consider public and other agency comments, respond to these comments in its final EIS, and wait 60 days before issuing a final decision. The CBD further states that before the record of decision has been issued on the final PEIS, NMFS cannot authorize CPAI's proposed seismic surveys because the purpose of the PEIS process is to consider seismic surveys in the Chukchi and Beaufort Seas for the years 2008 and beyond. The CBD states that NMFS seems to either be relying on a NEPA document that is not just inadequate, but which by its very terms only covers activities from two years ago (the 2006 PEA), or one which is nowhere near complete (the 2007 DPEIS).                

*Response:*                     See                     *Response*                     to                     *Comment 43*                     on this concern. Contrary to the NSB's and CBD's statement, NMFS relied on information contained in the MMS 2006 Final PEA, as updated by NMFS' 2008 SEA for making its determinations under NEPA and that the DPEIS was not the underlying document to support NMFS' issuance of CPAI's IHA. NMFS merely relied upon specific pieces of information and analyses contained in the DPEIS to assist in preparing the SEA. It is NMFS' intention that the PEIS currently being developed will be used to support, in whole, or in part, future MMPA actions relating to oil and gas exploration (i.e., seismic surveys) in the Arctic Ocean. Additionally, NMFS believes that a SEA is the appropriate NEPA analysis for this season as the amount of activity for 2008 is less than what was analyzed in the 2006 PEA.                

*Comment 45:*                     NVPH states that the MMS 2006 PEA is flawed since it understates the risk of significant impacts to bowhead whales, and therefore, it is inappropriate for NMFS to rely on that document. NVPH states that the 2006 PEA assumed the source vessels would ensonify much smaller zones than those which have been subsequently measured in the field. NVPH states that based on the propagation actually measured in 2006 and 2007, the impacts of a single 3D seismic survey are two to three times as large as NMFS anticipated or more. The impacts of a single shallow hazard survey are comparable to the impacts NMFS anticipated from a single 2D or 3D seismic survey. Before authorizing further seismic surveying activity or shallow hazard surveys in the Arctic Ocean, NVPH requests NMFS to complete the PEIS that it began in 2006 to evaluate the potentially significant impacts of such activities.                

*Response:*                     NMFS does not agree with NVPH's statement. First, the subject 2006 PEA was written by MMS, not NMFS. However, NMFS was a cooperating agency under NEPA in its preparation. Second, as noted in your cited part in the 2006 PEA, 20 km (12.4 mi) was used for illustrative purposes in an exercise to estimate impact of 4 seismic vessels operating within 24 km (15 mi) of each other. To do so, MMS created a box (that was moveable along the Beaufort or Chukchi Sea coast) to make these estimates. NMFS believes that the use of 20 km (12.4 mi) remains the best information available at this time and was the radius agreed to by participants at the 2001 Arctic Open-water Noise Peer Review Workshop in Seattle, Washington. This estimate is based on the results from the 1998 aerial survey (as supplemented by data from earlier years) as reported in Miller                     *et al.*                     (1999). In 1998, bowhead whales below the water surface at a distance of 20 km (12.4 mi) from an airgun array received pulses of about 117-135 dB re 1 μPa rms, depending upon propagation. Although NVPH states that propagation actually measured in 2006 and 2007 showed that the impacts of a single 3D seismic survey are two to three times as large as NMFS anticipated, NVPH failed to provide any data to support this statement. In fact, the marine mammal monitoring reports for the 2006 and                           ( print page 49436)                        2007 open water seismic surveys clearly showed that at 20 km (12.4 mi) the received levels from large airgun arrays used in 3D seismic surveys fall between 140 and 160 dB re 1 microPa (Ireland                     *et al.*, 2007a; 2007b; Patterson                     *et al.*, 2007; Funk                     *et al.*, 2007; 2008), which is below NMFS current noise exposure standard for Level B behavioral harassment. For this reason, until more data collection and analyses are conducted on impacts of anthropogenic noise (principally from seismic) on marine mammals in the Beaufort and Chukchi seas, NMFS will continue to use 20 km (12.4 mi) as the radius for estimating impacts on bowhead whales during the fall migration period.                

*Comment 46:*                     NVPH states that the MMS 2006 PEA fails to provide site-specific analysis. Thus, in order to reduce the likelihood of significant impacts, NMFS has imposed 160 dB and 120 dB safety zones when authorizing surveys pursuant to the PEA. At a minimum, it must do the same for CPAI's surveys but with the modifications to the safety zones discussed above.                

*Response:*                     NMFS does not agree with NVPH's statement. Although the MMS 2006 PEA did not explicitly provide site-specific analysis on the proposed CPAI shallow hazard and site clearance surveys, NMFS SEA prepared for the 2008 open-water season described its specific location and time of operation. As in the PEA, NMFS' 2008 SEA has described additional mitigation measures such as imposing the 160 dB safety zone for seismic activities in the Chukchi Sea when an aggregation of 12 or more bowhead or gray whales is sighted. This mitigation measure is required in the IHA issued to CPAI. Regarding imposing the 120-dB safety zone, it would pose safety and practical concerns for marine mammal monitoring in the Chukchi Sea. Therefore, a safety zone based on received level of 120 dB re 1 microPa will not be imposed in the Chukchi Sea as it has been determined to be impracticable under the MMPA.                

*Comment 47:*                     The NVPH and NSB state that the scope of the MMS 2006 PEA is explicitly limited to activities that occur during 2006, and that those seismic survey activities have already occurred, as well as an additional season worth of activities in 2007. NVPH states that the PEA does not evaluate activities that will occur over a period of several years, though NMFS has continued to rely on it as if its scope were for a multi-year program of seismic surveys. In addition, NVPH states that the PEA uses arbitrary significance criteria for non-endangered marine mammals that would allow long-lasting impacts to populations, or in fact the entire Arctic ecosystem, that would nonetheless be deemed insignificant. NVPH states that these significance criteria are inappropriate for an evaluation of impacts from seismic surveys, as indicated by MMS' use of more defensible significance criteria based on potential biological removal form marine mammal populations affected by seismic surveys in the Gulf of Mexico.                

*Response:*                     NMFS does not agree with the NVPH and NSB's statement, as failed to provide any support for their position. The MMS 2006 PEA, in which NMFS was a cooperating agency, provided a thorough description and analysis on the affected environment, including ESA-listed and non-ESA-listed species. Under the NEPA, there is no “significance criteria for non-endangered” species. The criteria for determining whether a proposed action would result in significant effects to the environment are contained in CEQ's regulations. NVPH's statement that MMS' such analysis “would allow long-lasting impacts to populations, or in fact the entire Arctic ecosystem, that would nonetheless be deemed insignificant” in a way supports the MMS 2006 PEA. In addition, NMFS has prepared and released to the public an SEA for the proposed 2008 Arctic seismic surveys in the Chukchi and Beaufort Seas (see                     **ADDRESSES**                     for availability). This SEA incorporates by reference the relevant information contained in the 2006 PEA and updates that information where necessary to assess impacts on the marine environment from the 2008 seismic survey activities. Further, the SEA and FONSI considered the CEQ significance criteria (including the criteria developed by NMFS) to determine whether take of marine mammals incidental to CPAI's seismic survey would result in significant impacts to the human environment. NMFS believes that the agency has complied with the requirements of NEPA in its preparation of its NEPA documents.                

*Comment 48:*                     Oceana and Ocean Conservancy are concerned that oil and gas activities may have substantial negative effects on marine mammals and other Arctic species. Oceana and Ocean Conservancy further state that there has never been a comprehensive evaluation of the cumulative effects of seismic activities in the Arctic. Oceana and Ocean Conservancy request that in light of the dramatic effects of climate change in the Arctic, NMFS must not approve further seismic activities without such a comprehensive evaluation.                

*Response:*                     NMFS shares Oceana and Ocean Conservancy's concern that the increasing industrial activities, including oil and gas development, could have profound negative effects on marine mammals in the Arctic region. Nevertheless, NMFS believes that proactive efforts to conserve and protect marine mammals and other Arctic species, such as NMFS' initiation of status reviews of ice seals and the recent FWS' ESA-listing of polar bears, combined with prudent natural resources management and regulations on industrial activities by Federal Agencies would reduce these adverse impacts to biologically non-significant or negligible levels. In addition, monitoring and mitigation measures required for certain industrial activities would further reduce and minimize such negative effects to marine mammal species and stocks. Long term research and monitoring results on ice seals in the Alaska's North Slope have shown that effects of oil and gas development on local distribution of seals and seal lairs are no more than slight, and are small relative to the effects of natural environmental factors (Moulton                     *et al.*, 2005; Williams                     *et al.*, 2006).                

NMFS does not agree with Ocean and Ocean Conservancy's statement that there has never been a comprehensive evaluation of the cumulative effects of seismic activities in the Arctic. The MMS 2006 PEA, NMFS 2007 SEA, MMS 2007 draft PEIS, and NMFS 2008 SEA for the proposed issuance of five seismic survey and shallow hazard and site clearance survey activities for the 2008 open water season all provide comprehensive evaluation of the cumulative effects of seismic activities in the Arctic.

*Comment 49:*                     NSB and CBD are both concerned about cumulative impacts from multiple operations. CPAI's proposal is only one of numerous oil industry activities recently occurring, planned, or ongoing in the U.S. portions of the Chukchi and Beaufort Seas (e.g., proposed IHA for on-ice seismic surveys in Harrison Bay; proposed scientific seismic survey by the National Science Foundation (NSF); NMFS' 5-year regulations for activities related to Northstar; SOI IHA for Beaufort Sea exploratory drilling; CPAI IHA for Beaufort Sea; SOI IHA for Beaufort Sea; two proposed IHAs for Chukchi Sea and two proposed for the Beaufort Sea; and FWS 5-year regulations for oil and gas activities in the Beaufort Sea). No analysis of seismic surveys in the Russian or Canadian portions of the Chukchi and Beaufort seas is mentioned                           ( print page 49437)                        either. Similarly, significant increases in onshore oil and gas development with attendant direct impacts and indirect impacts on marine mammals such as through increased ship traffic are also occurring and projected to occur at greater rates than in the past. CBD states that further cumulative effects impacting the marine mammals of the Beaufort and Chukchi Seas are outlined in their NEPA comments on the MMS PEA and the DPEIS.                

The NSB points out that in addition to the proposed offshore industrial operations listed above, there will be supply and fuel barging to villages, barging for support of onshore development and exploration, scientific cruises, climate change studies, USCG operations, tourist vessel traffic, and other activities as well. The cumulative impacts of all these activities must be factored into any negligible impact determination. Further, without an analysis of the effects of all of the planned operations, it is impossible to determine whether the monitoring plans are sufficient.

*Response:*                     Under section 101(a)(5)(D) of the MMPA, NMFS is required to determine whether the taking by the applicant's specified activity will have a negligible impact on the affected marine mammal species or population stocks. Cumulative impact assessments are NMFS' responsibility under NEPA, not the MMPA. In that regard, the MMS Final PEA and NMFS SEA address cumulative impacts. The Final PEA's cumulative activities scenario and cumulative impact analysis focused on oil and gas-related and non-oil and gas-related noise-generating events/activities in both Federal and State of Alaska waters that were likely and foreseeable. Other appropriate factors, such as Arctic warming, military activities, and noise contributions from community and commercial activities were also considered. Appendix D of the Final PEA addresses similar comments on cumulative impacts, including global warming. That information was incorporated into and updated in the NMFS 2008 SEA and into this document by citation. NMFS adopted the MMS Final PEA, and it is part of NMFS' Administrative Record. Finally, NMFS does not require authorizations under section 101(a)(5) of the MMPA for normal shipping or transit.                

*Comment 50:*                     According to CBD, another factor causing NMFS' “negligible impact” findings to be suspect is the fact that the Chukchi Sea area is undergoing rapid change as a result of global warming. For species under NMFS' jurisdiction, and therefore subject to the proposed IHA, seals are likely to face the most severe consequences. The Arctic Climate Impact Assessment (ACIA) concluded that ringed, spotted, and bearded seals would all be severely negatively impacted by global warming this century. The ACIA stated that ringed seals are particularly vulnerable: “Ringed seals are likely to be the most highly affected species of seal because all aspects of their lives are tied to sea ice” (ACIA, 2004). In 2003, the NRC noted that oil and gas activities combined with global warming presented a serious cumulative impact to the species: “Climate warming at predicted rates in the Beaufort Sea region is likely to have serious consequences for ringed seals and polar bears, and those effects will accumulate with the effects of oil and gas activities in the region.” NMFS' failure to address global warming as a cumulative effect renders its negligible impact findings invalid.                

*Response:*                     Under section 101(a)(5)(D) of the MMPA, “the Secretary shall authorize... taking by harassment of small numbers of marine mammals of a species or population stock by such citizens while engaging in that activity within that region if the Secretary finds that such harassment during each period concerned (I) will have a negligible impact on such species or stock, and (II) will not have an unmitigable adverse impact on the availability of such species or stock for taking for subsistence uses.” Section 101(a)(5)(D) of the MMPA does not require NMFS to base its negligible impact determination on the possibility of cumulative effects of other actions.                

As stated in previous responses, cumulative impact assessments are NMFS' responsibility under NEPA, not the MMPA. In that regard, the MMS 2006 Final PEA and NMFS' 2008 SEA address cumulative impacts. The PEA's cumulative activities scenario and cumulative impact analysis focused on oil and gas-related and non-oil and gas-related noise-generating events/activities in both Federal and State of Alaska waters that were likely and foreseeable. Other appropriate factors, such as Arctic warming, military activities, and noise contributions from community and commercial activities were also considered. Appendix D of the PEA addresses similar comments on cumulative impacts, including global warming. That information was incorporated into and updated in the NMFS 2008 SEA and into this document by citation. NMFS adopted the MMS Final PEA, and it is part of NMFS' Administrative Record.

### Endangered Species Act

*Comment 51:*                     The CBD states that the proposed IHA will affect, at a minimum, four endangered species, the bowhead, humpback and fin whales, and the polar bear. The CBD and ICAS states that as a consequence, NMFS must engage in consultation under Section 7 of the ESA prior to issuing the IHA. Previous recent biological opinions for industrial activities in the Arctic (e.g., the 2006 Arctic Regional Biological Opinion (ARBO)) have suffered from inadequate descriptions of the proposed action, inadequate descriptions of the status of the species, inadequate descriptions of the environmental baseline, inadequate descriptions of the effects of the action, inadequate analysis of cumulative effects, and inadequate descriptions and analysis of proposed mitigation. The CBD hopes NMFS performs the full analysis required by law and avoids these problems in its consultation for the proposed IHA. CPAI encourages NMFS to complete a thorough section 7 consultation with FWS to assure that coverage for polar bear and walrus is addressed.                

*Response:*                     Under section 7 of the ESA, NMFS has completed consultation with the MMS on the issuance of seismic permits for offshore oil and gas activities in the Beaufort and Chukchi seas. In a Biological Opinion issued on July 17, 2008, NMFS concluded that the issuance of seismic survey permits by MMS and the issuance of the associated IHAs for seismic surveys are not likely to jeopardize the continued existence of threatened or endangered species (specifically the bowhead, humpback, and fin whales) under the jurisdiction of NMFS or destroy or adversely modify any designated critical habitat. The 2008 Biological Opinion takes into consideration all oil and gas related activities that are reasonably likely to occur, including exploratory (but not production) oil drilling activities. In addition, NMFS has issued an Incidental Take Statement under this Biological Opinion which contains reasonable and prudent measures with implementing terms and conditions to minimize the effects of take of bowhead, humpback, and fin whales. Regarding the polar bear, MMS has contacted the FWS about conducting a section 7 consultation. Walrus is not an ESA-listed species, therefore, a section 7 consultation is not warranted.                

*Comment 52:*                     The CBD states that NMFS may authorize incidental take of the listed marine mammals under the ESA pursuant to Section 7(b)(4) of the ESA, but only where such take occurs while “carrying out an otherwise lawful                           ( print page 49438)                        activity.” To be “lawful,” such activities must “meet all State and Federal legal requirements except for the prohibition against taking in section 9 of the ESA.” The CBD states that CPAI's proposed activities violate the MMPA and NEPA and therefore are “not otherwise lawful.” The CBD concludes that any take authorization for listed marine mammals would, therefore, violate the ESA, as well as these other statutes.                

*Response:*                     NMFS does not agree with the CBD statement. As noted in this document, NMFS has made the necessary determinations under the MMPA, the ESA, and NEPA regarding the incidental harassment of marine mammals by CPAI while it is conducting activities permitted legally under MMS' jurisdiction.                

### Other Comments

*Comment 53:*                     To assist with its ability to plan and coordinate its programs in the remote area of the Chukchi Sea, CPAI requests that NMFS expedite their decision on the IHA after the 30-day public comment period closes on June 23, 2008.                

*Response:*                     Comment noted. Nevertheless, in order to make an sound determination regarding whether CPAI's proposed shallow hazard and site clearance surveys would have a negligible impacts to marine mammals and unmitigable adverse affects to subsistence harvest of marine mammals in the Arctic region, NMFS has taken the time to thoroughly review all relevant documents on the proposed activities. Especially as CPAI indicated that it will not sign a CAA with the AEWC, NMFS is obligated to review and evaluate the CAA and stipulate certain conditions in the IHA to CPAI to ensure that the shallow hazard and site clearance survey would not have an unmitigable adverse impact on the availability of marine mammal species or stocks for taking for subsistence uses.                

## Description of Marine Mammals in the Activity Area

                    In general, the marine mammal species under NMFS' management authority that occur in or near the proposed survey area within the Chukchi Sea are the bowhead (                    *Balaena mysticetus*), gray (                    *Eschrichtius robustus*), humpback (                    *Megaptera novaeangliae*), fin (                    *Balaenoptera physalus*), minke (                    *B. acutorostrata*), beluga (                    *Delphinapterus leucas*), and killer whales (                    *Orcinus orca*); harbor porpoises (                    *Phocoena phocoena*); and the bearded (                    *Erignathus barbatus*), ringed (                    *Phoca hispida*), spotted (                    *P. largha*), and ribbon seals (                    *P. fasciata*). Among these species, the bowhead, humpback, and fin whales are listed as “Endangered” under the Endangered Species Act (ESA).                

                    A detailed description of the biology, population estimates, and distribution and abundance of these species is provided in CPAI's IHA application. Additional information regarding the stock assessments of these species is in NMFS Alaska Marine Mammal Stock Assessment Report (Angliss and Outlaw, 2008), and can also be assessed via the following URL link:                     *http://www.nmfs.noaa.gov/​pr/​pdfs/​sars/​ak2007.pdf*. Additional information on those species that are under NMFS' management authority within or near the proposed survey areas is described in the FR Notice of Proposed IHA and is not repeated here.                

## Potential Effects on Marine Mammals

Operating a variety of acoustic equipment such as side-scan sonars, echo-sounders, bottom profiling systems, and airguns for seafloor imagery, bathymetry, and seismic profiling has the potential for adverse affects on marine mammals.

### Potential Effects of Airgun Sounds on Marine Mammals

                    The effects of sounds from airguns might include one or more of the following: tolerance, masking of natural sounds, behavioral disturbance, and, at least in theory, temporary or permanent hearing impairment, or non-auditory physical or physiological effects (Richardson                     *et al.*, 1995)                

 The potential effects of airguns discussed below are presented without consideration of the mitigation measures that CPAI has presented and that will be required by NMFS. When these measures are taken into account, it is unlikely that this project would result in temporary, or especially, permanent hearing impairment or any significant non-auditory physical or physiological effects.

#### (1) Tolerance

Numerous studies have shown that pulsed sounds from airguns are often readily detectable in the water at distances of many kilometers. Studies have also shown that marine mammals at distances more than a few kilometers from operating seismic vessels often show no apparent response (tolerance). 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 are baleen whales.

#### (2) Masking

                    Masking effects of pulsed sounds (even from large arrays of airguns) on marine mammal calls and other natural sounds are expected to be limited, although there are very few specific data of relevance. Some whales are known to continue calling in the presence of seismic pulses. Their calls can be heard between the seismic pulses (e.g., Richardson                     *et al.*, 1986; McDonald                     *et al.*, 1995; Greene                     *et al.*, 1999; Nieukirk                     *et al.*, 2004). Although there has been one report that sperm whales cease calling when exposed to pulses from a very distant seismic ship (Bowles                     *et al.*, 1994), a more recent study reports that sperm whales off northern Norway continued calling in the presence of seismic pulses (Madsen                     *et al.*, 2002). That has also been shown during recent work in the Gulf of Mexico (Tyack                     *et al.*, 2003; Smultea                     *et al.*, 2004). Masking effects of seismic pulses are expected to be negligible in the case of the smaller odontocete cetaceans, given the intermittent nature of seismic pulses. Dolphins and porpoises commonly are heard calling while airguns are operating (e.g., Gordon                     *et al.*, 2004; Smultea                     *et al.*, 2004; Holst                     *et al.*, 2005a; 2005b). Also, the sounds important to small odontocetes are predominantly at much higher frequencies than are airgun sounds.                

#### (3) Disturbance Reactions

Disturbance includes a variety of effects, including subtle changes in behavior, more conspicuous changes in activities, and displacement.

Reactions to sound, if any, depend on species, state of maturity, experience, current activity, reproductive state, time of day, and many other factors. If a marine mammal does react briefly to an underwater sound by slightly changing its behavior or moving a small distance, the impacts of the change are unlikely to be biologically significant to the individual, let alone the stock or the species as a whole. However, if a sound source displaces marine mammals from an important feeding or breeding area for a prolonged period, impacts on the animals could be significant.

#### (4) Hearing Impairment and Other Physical Effects

                    Temporary or permanent hearing impairment is a possibility when marine                           ( print page 49439)                        mammals are exposed to very strong sounds, but there has been no specific documentation of this for marine mammals exposed to sequences of airgun pulses. NMFS advises against exposing cetaceans and pinnipeds to impulsive sounds above 180 and 190 dB re 1 microPa (rms), respectively (NMFS, 2000). Those thresholds have been used in defining the safety (shut down) radii planned for the proposed seismic surveys. Although those thresholds were established before there were any data on the minimum received levels of sounds necessary to cause temporary auditory impairment in marine mammals, they are considered to be conservative.                

Several aspects of the planned monitoring and mitigation measures for this project are designed to detect marine mammals occurring near the airguns to avoid exposing them to sound pulses that might, at least in theory, cause hearing impairment (see Mitigation and Monitoring section below). In addition, many cetaceans are likely to show some avoidance of the area with high received levels of airgun sound. In those cases, the avoidance responses of the animals themselves will reduce or (most likely) avoid any possibility of hearing impairment.

Non-auditory physical effects may also 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. It is possible that 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. It is unlikely that any effects of these types would occur during the proposed project given the brief duration of exposure of any given mammal, and the planned monitoring and mitigation measures (see below).

#### (5) Strandings 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 energetic and have slower rise times, and there is no evidence that they can cause serious injury, death, or stranding even in the case of large airgun arrays.                

Nonetheless, the airgun array proposed to be used in the proposed site clearance surveys in Chukchi Sea is small in volume (40 cu inches) and the source level is expected at 196 dB re 1 mircoPa (peak), which is approximately 190 dB re 1 microPa (rms). The 160, 170, and 180 dB re 1 microPa (rms) radii, in the beam below the transducer, would be 32 m (104 ft), 10 m (33 ft), and 3.2 m (10 ft), respectively, for the 40-cu-inch airgun array, assuming spherical spreading.

### Possible Effects of Bathymetry Echo Sounder Signals

Two types of bathymetry echo sounders are planned to be used for the proposed surveys. The Odom Hydrotrac Digital Echo Sounder is a single beam echo sounder that emits a single pulse of sound directly below the ship along the vessel trackline and provides a continuous recording of water depth along the survey track. The second sonar is a Reson Seabat 8101 Multibeam Echo Sounder, which consists of a transducer array that emits a swath of sound. The seafloor coverage swath of the multibeam sonar is water depth dependent, but is usually equal to two to four times the water depth. Nonetheless both echo sounders produce acoustic signals above 200 kHz which is above any marine mammal species' upper hearing threshold, therefore, NMFS does not believe that there will be any effects on marine mammals as a result from operating these sonars.

### Possible Effects of Sub-bottom Profiler Signals

A high resolution subbottom profiler (GeoAcoustics GeoPulse sub-bottom profiling system or GeoAcoustics GeoChirp II sub-bottom profiling system) and an intermediate frequency seismic profiling system (“boomer”) are planned to be used for the proposed surveys.

The frequency range for these high resolution subbottom profilers are 3.5 to 5 kHz for the GeoPulse and 500 Hz to 13 kHz for the GeoChirp II. Either subbottom profiler has a source level at approximately 214 dB re 1 microPa-m (rms). The 160, 170, 180, and 190 dB re 1 microPa (rms) radii, in the beam below the transducer, would be 501 m (1,644 ft), 158 m (520 ft), 50 m (164 ft), and 16 m (52 ft), respectively, for either subbottom profiler, assuming spherical spreading.

The Applied Acoustics Model AA300 intermediate frequency seismic profiler (“boomer”) has a maximum energy input of 350 J per shot, though the maximum energy would be used in the surveys is 300 J. The pulse length ranges from 150 msec to 400 msec with a reverberation of less than 1/10 of the initial pulse. The peak in the source level beam reaches 218 dB re 1 microPa-m (or 209 dB re 1 microPa-m (rms)) at 300 J with a frequency range of 500 Hz to 300 kHz. The 160, 170, 180, and 190 dB re 1 microPa (rms) radii, in the beam below the transducer, would be 282 m (925 ft), 89 m (292 ft), 28 m (92 ft), and 9 m (29 ft), respectively, assuming spherical spreading.

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

### Possible Effects of Side-Scan Sonar Signals for Seafloor Imagery

One of the two types of side-scan sonars is planned to be used for the proposed shallow hazard and site clearance surveys for seafloor imagery. The EdgeTech 4200 dual-frequency side scan sonar operates at 120 kHz up to 410 kHz, with source level reaching 210 dB re 1 microPa-m (rms). The 160, 170, 180, and 190 dB re 1 microPa (rms) radii, in the beam below the transducer, would be 316 m (1,037 ft), 100 m (328 ft), 32 m (104 ft), and 10 m (33 ft), respectively, assuming spherical spreading.

                    The Klein System 3000 dual-frequency digital side-scan sonar emits pulses between 25 msec and 400 msec. The peak in the 132 kHz source level beam reaches 234 dB re 1 microPa-m (or 225 dB re 1 microPa-m (rms)). The peak in the 445 kHz source level beam reaches 242 dB re 1 microPa-m. The 445 kHz frequency band is outside any marine mammal species' hearing range, therefore, there would be no effect to marine mammals when this frequency is chosen. The 160, 170, 180, and 190 dB re 1 microPa (rms) radii, in the beam below the transducer, would be 1,778 m (5,834 ft), 562 m (1,844 ft), 178 m (583 ft), and 56 m (184 ft), respectively, assuming spherical spreading.                          ( print page 49440)    

                    Nonetheless, these side scan sonars operate in an extremely high frequency range (over 120 kHz) relative to marine mammal hearing (Richardson                     *et al.*, 1995; Southall                     *et al.*, 2007). The frequency range from these side scan sonars is beyond the hearing range of mysticetes (baleen whales) and pinnipeds. Therefore, these sonars are not expected to affect bowhead, gray, humpback, fin, and minke whales and pinniped species in the proposed project area. The frequency range from these side scan sonars falls within the upper end of odontocete (toothed whale) hearing spectrum (Richardson                     *et al.*, 1995), which means that they are not perceived as loud acoustic signals with frequencies below 120 kHz by these animals. Therefore, these animals would not react to the sound in a biologically significant way. Further, in addition to spreading loss for acoustic propagation in the water column, high frequency acoustic energies are more quickly absorbed through the water column than sounds with lower frequencies (Urick, 1983). Therefore, NMFS believes that the potential effects from side scan sonar to marine mammals are negligible.                

## Numbers of Marine Mammals Estimated to be Taken

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

                    Take was calculated for the two areas of the study area using vessel-based density estimates. Few bowheads and no belugas were observed during the vessel surveys conducted in the Chukchi Sea by LGL                     *et al.*                     (2008), although the surveys used multiple vessels achieving substantial effort and coverage from early July to mid November. This result is generally consistent with the historic information, which shows that bowheads generally migrated through the Chukchi Sea to the Beaufort Sea by mid-late June, and do not return until about late October and November, probably reaching the region of the project area no earlier than late October (LGL                     *et al.*, 2008). Similarly, most belugas migrate to the northern Chukchi Sea and westward into the Beaufort Sea by mid to late July and return to the region of the project area in late October and November (Suydam                     *et al.*, 2005). Although LGL                     *et al.*, (2008) did not observe belugas offshore in 2006 or 2007, they did encounter belugas along the coast in decreasing numbers from July to October/November during aerial surveys. LGL                     *et al.*                     (2008) also observed bowheads in the fall near Barrow during nearshore aerial surveys, suggesting the whales had not moved very far into Chukchi Sea at that time. While these data and the historic information suggest the take calculations are reasonable for belugas and bowheads, the take numbers have been adjusted to 10 animals for each species to account for the possible occurrence of more animals than estimated in the project area during operations due to an early freeze-up or other unanticipated changes in the environment. This adjustment is generally consistent with estimates based on less current densities used in past IHAs for bowhead (0.0011/km2) and beluga (0.0034/km2                    ) whales for late fall.                

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

                    JASCO modeled the sound levels of different configurations of seismic profilers (10 kj and 16 kj sparkers, 10 in3                     and 20 in3                     2-gun arrays, 40 cu3                     single gun, and 10 in3                     4-gun array) and found the 4-gun array produced the highest sound levels. Therefore, all take estimates of marine mammals are calculated for the 4-gun array in this proposed activity, which reaches the 160 dB re 1 microPa sound level at 1,665 m (5,463 ft) from the source, the 180 dB re 1 microPa level at 115 m (377 ft), and the 190 dB level at 20 m (66 ft).                

                    The average estimates of “take” were calculated by multiplying the expected average animal densities by the area of ensonification for the 160 dB re 1 microPa (rms). The area of ensonification was determined by multiplying the total proposed trackline of 5,300 km (3,294 mi)(2,120 km, or 1,318 mi, in August; 2,120 km, or 1,318 mi, in September; and 1,060 km, or 659 mi, in October) times 2 (both sides of the trackline) times the distance to the 160-dB isopleth. The distance to the 160-dB isopleth was estimated as approximately 1,665 m (5,463 ft) with a corresponding area of ensonification of 17,649 km2                     (6,817 mi2                    ).                

                    The Level B harassment take estimate of 1,379 ringed seals is a small number at least in relative terms, in that it represents approximately 0.55 percent of the Alaska stock size of that species (249,000) in the Chukchi Sea, if each “exposure” at 160 dB represents an individual ringed seal. The percentage would be even lower if a higher SPL is required for a behavioral reaction (as is expected), or, if as expected, animals move out of the seismic area. As a result, we believe that these “exposure” estimates are conservative, and seismic surveys will actually affect less than 0.55 percent of the ringed seal population. For the remaining potentially affected marine mammal species, NMFS expects that approximately 10 bowhead, 37 gray whales, 42 harbor porpoises, and 376 bearded seals would be taken by Level B behavioral harassment as a result of the proposed site clearance surveys. These take numbers represent 0.09, 0.19, 0.66, and 0.15 percent of the western Arctic stock of bowhead whales, eastern North Pacific stock of gray whales, Bering Sea stock of harbor porpoise, and Arctic stock of bearded seals in the Chukchi Sea region. These numbers are small relative to their respective stock or population sizes. In addition, NMFS expects that 4 minke whales and 72 spotted seals would be taken by Level B harassment. However, a specific estimate of the percentage of Level B harassment of these species cannot be determined because no accurate current population estimates of minke whales and spotted seals are available. Nevertheless, based on the information available, NMFS believes these numbers are very low relative to the populations of these species in the proposed project area because: (1) for the minke whales, the Chukchi Sea is not typical habitat, and visual surveys in 1999 and 2000 counted 810 and 1,003 minke whales in the central-eastern and southeastern Bering Sea, respectively, not including animals missed on the trackline, or animals submerged when the ship passed; and (2) for the spotted seal, the early population estimate of this species ranged from 335,000-450,000 seals, and there is no reason to believe that the population of this species has declined significantly. In addition, a number of beluga, humpback, and killer whales, and ribbon seals could also be affected by Level B behavioral harassment as a result of the proposed marine surveys in the Chukchi Sea. However, since the occurrence of these marine mammals is very rare within the proposed project area during the late summer and fall in the Chukchi Sea, take numbers cannot be estimated. In the event these species                           ( print page 49441)                        are present in the proposed project area, NMFS believes their numbers would be limited; thus, should take occur from the seismic survey, NMFS would expect the numbers to be small, particularly in light of the fact that these animals do not frequent the project area.                

                    NMFS believes the number of potential takes by harassment is small and may be reduced further because of the proposed mitigation measures, including curtailing seismic activities during the bowhead migratory period to protect the Native subsistence hunt. Additionally, because the seismic airguns used by CPAI are of small discharge volumes (40 in3                    , compared to the 3,000+ in3                     arrays used in 2D or 3D deep seismic surveys), the ensonified zones within which marine mammals could be adversely affected are very small (approximately 50 km2                     for the 160-dB isopleths at any given time as compared to 15,000 km2 for a 3,000+ in3                     array [e.g., SOI's proposed 3D seismic survey in the Chukchi Sea]).                

## Potential Impacts to Subsistence Harvest of Marine Mammals

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

Alaska Natives, including the Inupiat, legally hunt several species of marine mammals. Communities that participate in subsistence activities potentially affected by seismic surveys within the proposed survey areas are Point Hope, Point Lay, Wainwright, and Barrow. Marine mammals used for subsistence in the proposed area include: bowhead whales, beluga whales, ringed seals, spotted seals, bearded seals, Pacific walrus, and polar bears. In each village, there are key subsistence species. Hunts for these animals occur during different seasons throughout the year. Depending upon the village's success of the hunt for a certain species, another species may become a priority in order to provide enough nourishment to sustain the village.

Point Hope residents hunt for bowhead and beluga whales, polar bears and walrus. Bowhead and beluga whales are hunted in the spring and early summer along the ice edge. Beluga whales may also be hunted later in the summer along the shore. Walrus are harvested in late spring and early summer, and polar bear are hunted from October to April (MMS, 2007). Seals are available from October through June, but are harvested primarily during the winter months, from November through March, due to the availability of other resources during the other periods of the year (MMS, 2007).

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

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

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

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

In an effort to minimize or avoid any adverse effects to subsistence harvest, CPAI has met with key native organizations responsible for managing marine mammals in the Arctic. In accordance with 50 CFR 126.104(a)(12), CPAI has met with subsistence stakeholder in the communities and villages of Kivalina, Kotzebue, Wainwright, Barrow, Point Lay, and Point Hope and developed a POC for its proposed 2008 shallow hazard and site clearance survey.

                    CPAI has not signed the 2008 CAA with Alaska Natives and has informed NMFS that it does not intend to do so. As explained above in                     *Response*                     to                     *Comment 33*, NMFS has scrutinized all of the documents submitted by CPAI (e.g., IHA application, Plan of Cooperation and other correspondence to NMFS and affected stakeholders) and documents submitted by other affected stakeholders and concluded that harassment of marine mammals incidental to CPAI's activities will not have an unmitigable adverse impact on the availability of marine mammals for taking for subsistence uses.                

In addition, CPAI has indicated that a number of actions would be taken by CPAI during the surveys to minimize any adverse effect on the availability of marine mammals for subsistence, which have been proposed in the CPAI application. They include the following:

(1) Site clearance and shallow hazard surveys will occur in areas considerably distant to the villages during the hunting periods (i.e., up to 70 miles offshore);

(2) Site clearance and shallow hazard surveys will follow procedures of changing vessel course, powering down, and shutting down acoustic equipment to minimize effects on the behavior of marine mammals. These measures are likely to afford greater access by subsistence users to marine mammals should any harvest occur in the project area; and

(3) In the unlikely event that a hunter is encountered, operations will be managed to keep the hunter and seismic vessel at least 5 km (3.1 mi) apart.

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

Finally, in the event harvest activities do occur this far offshore, the required mitigation and monitoring measures are expected to reduce any adverse impacts on marine mammals for taking for subsistence uses to the extent practicable. These measures include, but are not limited to, the 180 dB and 190 dB safety (shut-down/power-down) zones; a requirement to monitor the 160 dB isopleth for aggregations of 12 or more non-migratory balaenidae whales and when necessary shut-down seismic airguns; maintaining a distance of at least 15 miles from other operating seismic vessels; reducing vessel speed when a vessel is within 300 yards of whales to avoid a collision; utilizing communication centers to avoid any conflict with subsistence hunting activities; and the use of marine mammal observers. Many of these requirements are consistent with the measures contained in the 2008 CAA entered into between other industry participants who operate in the Chukchi Sea and Alaska Natives.

## Potential Impacts on Habitat

                    The proposed site clearance surveys would not result in any permanent impact on habitats used by marine mammals, or to the food sources they use. The main impact issue associated                           ( print page 49442)                        with the proposed activity would be temporarily elevated noise levels and the associated direct effects on marine mammals, as discussed above.                

## Monitoring and Mitigation Measures

### Monitoring

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

#### (1) Proposed Safety Zones

Based acoustic propagation modeling performed by JASCO, it is estimated that distance from the seismic sources to the 180 dB isopleth is approximately 115 m (377 ft), and the distance to the 190 dB isopleth is about 20 m (66 ft). Because these values are based on modeling instead of field measurement during actual operations, NMFS requires, as a precautionary measure, safety radii of 120 m (393 ft) for cetaceans and 24 m (79 ft) for pinnipeds.

In addition, a 160-dB vessel monitoring zone for bowhead and gray whales shall be established and monitored during all seismic surveys. Whenever an aggregation of 12 or more bowhead whales or gray whales are observed during a 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 indicate they are no longer present within the 160-dB safety zone of seismic-surveying operations. The radius of 160-dB isopleth based on modeling is 1,665 m (5,463 ft).

Before the commencement of the shallow hazard and site clearance survey, CPAI is required to conduct empirical measurements of acoustic sources to be used in the seismic survey and verify the radii of the modeled safety zones at 160, 170, 180, and 190 dB re 1 microPa (rms).

#### (2) Vessel-based Visual Monitoring

Marine mammal monitoring during the site clearance surveys would be conducted by qualified, NMFS-approved marine mammal observers (MMOs). Vessel-based MMOs would be on board the seismic source vessel to ensure that no marine mammals would enter the relevant safety radii of 180 and 190-dB isopleths while noise-generating equipment is operating. Monitoring will also be conducted to include the larger 160-dB safety zone for an aggregation of 12 or more bowhead or gray whales.

#### (3) Communication between Vessel and Shore

Communication of vessel operations and transit would occur in accordance with protocols set forth by the Com and Call Centers proposed to be operated in Barrow, Point Hope, and Point Lay. This would further enable vessel operators to be aware of marine mammals and subsistence activity in the area.

### Mitigation

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

#### (1) Speed or Course Alteration

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

#### (2) Shut down Procedures

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

Following a shut down, acoustic equipment would not be turned on until the marine mammal is outside the safety zone. The animal would be considered to have cleared the safety zone if it (1) is visually observed to have left the 120-m or 24-m safety zone, for a cetacean or a pinniped species, respectively; or (2) has not been seen within the relevant safety zone for 15 minutes in the case of odontocetes and pinnipeds, and for 30 minutes in the case of mysticetes. For the aggregation of bowhead or gray whales, the seismic equipment will not be turned on until the aggregation has left the 1,665-m safety zone or the animals forming the aggregation are reduced to fewer than 12 bowhead or gray whales.

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

#### (3) Ramp-up Procedures

A ramp-up procedure will be followed when the acoustic sources begin operating after a specified period without operations. It is proposed that, for the present survey, this period would be 30 min. Ramp up would begin with the power on of the smallest acoustic equipment for the survey at its lowest power output. The power output would be gradually turned up and other acoustic sources would be added in a way such that the source level would increase in steps not exceeding 6 dB per 5-min period. During ramp-up, the MMOs would monitor the safety zone, and if marine mammals are sighted, decisions about course/speed changes and/or shutdown would be implemented as though the acoustic equipment is operating at full power.

#### (4) Poor Visibility Conditions

CPAI plans to conduct 24-hr operations. The proposed provisions associated with operations at night or in periods of poor visibility include:

(1) During any nighttime operations, if the entire 180-dB safety radius is visible using vessel lights and/or night vision devices, then start of a ramp-up procedure after a complete shutdown of the airgun array may occur following a 30-min period of observation without sighting marine mammals in the safety zone.

(2) If during foggy conditions or darkness (which may be encountered starting in late August), the full 180-dB safety zone is not visible, the airguns cannot be ramped-up if the seismic source is in a full shutdown mode.

(3) If one or more airguns has been operational before nightfall or before the onset of foggy conditions, they can remain operational throughout the night or foggy conditions. In this case, ramp-up procedures can be initiated, even though the entire safety radius may not be visible, on the assumption that marine mammals will be alerted by the sounds from the single airgun and have moved away.

## Data Collection and Reporting

MMOs would record data to estimate the numbers of marine mammals present and to document apparent disturbance reactions or lack thereof. Data would be used to estimate numbers of animals potentially “taken” by harassment. They would also provide information needed to order a shut down of acoustic equipment when marine mammals are within or entering the safety zone.

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

                    (1) Species, group size, age/size/sex categories (if determinable), behavior when first sighted and after initial sighting, heading (if consistent), bearing                           ( print page 49443)                        and distance from seismic vessel, and apparent reaction to the acoustic sources or vessel.                

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

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

A final report will be submitted to NMFS within 90 days after the end of the shallow hazard and site clearance surveys. The report will describe the operations that were conducted and sightings of marine mammals near the operations. The report also will provide full documentation of methods, results, and interpretation pertaining to all monitoring. The report will summarize the dates and locations of seismic operations, and all marine mammal sightings (dates, times, locations, activities, associated seismic survey activities), and the amount and nature of potential take of marine mammals by harassment or in other ways.

## Endangered Species Act

Under section 7 of the ESA, NMFS has completed consultation with the MMS on the issuance of seismic permits for offshore oil and gas activities in the Beaufort and Chukchi seas. In a Biological Opinion issued on July 17, 2008, NMFS concluded that the issuance of seismic survey permits by MMS and the issuance of the associated IHAs for seismic surveys are not likely to jeopardize the continued existence of threatened or endangered species (specifically the bowhead, humpback, and fin whales) under the jurisdiction of NMFS or destroy or adversely modify any designated critical habitat. The 2008 Biological Opinion takes into consideration all oil and gas related activities that are reasonably likely to occur, including exploratory (but not production) oil drilling activities. In addition, NMFS has issued an Incidental Take Statement under this Biological Opinion which contains reasonable and prudent measures with implementing terms and conditions to minimize the effects of take of bowhead whales.

## NEPA

In 2006, the MMS prepared Draft and Final PEAs for seismic surveys in the Beaufort and Chukchi Seas. NMFS was a cooperating agency in the preparation of the MMS PEA. On November 17, 2006 (71 FR 66912), NMFS and MMS announced that they were preparing a DPEIS in order to assess the impacts of MMS' annual authorizations under the Outer Continental Shelf Lands Act to the U.S. oil and gas industry to conduct offshore geophysical seismic surveys in the Chukchi and Beaufort Seas off Alaska and NMFS' authorizations under the MMPA to incidentally harass marine mammals while conducting those surveys.

On March 30, 2007 (72 FR 15135), the Environmental Protection Agency (EPA) noted the availability for comment of the NMFS/MMS DPEIS. Based upon several verbal and written requests to NMFS for additional time to review the DPEIS, EPA has twice announced an extension of the comment period until July 30, 2007 (72 FR 28044, May 18, 2007; 72 FR 38576, July 13, 2007). Because NMFS has been unable to complete the PEIS, it was determined that the 2006 PEA would need to be updated in order to meet NMFS' NEPA requirement. This approach was warranted as it was reviewing five proposed Arctic seismic survey IHAs for 2008, well within the scope of the PEA's eight consecutive seismic surveys. To update the 2006 Final PEA, NMFS prepared a SEA which incorporates by reference the 2006 Final PEA and other related documents.

## Determination

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

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

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

## Authorization

As a result of these determinations, NMFS has issued an IHA to CPAI for conducting a shallow hazard and site clearance survey in the Chukchi Sea in 2008, provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated.

Dated: August 15, 2008.

James H. Lecky,

Director, Office of Protected Resources, National Marine Fisheries Service.

[FR Doc. E8-19424 Filed 8-20-08; 8:45 am]

BILLING CODE 3510-22-S