Marine mammals: Incidental taking; authorization letters, etc.— Marine Geographical Survey; Western Canada Basin, Chukchi Borderland, and Mendeleev Ridge, Arctic Ocean,

[Federal Register: August 1, 2006 (Volume 71, Number 147)]

[Notices]

[Page 43450-43470]

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

[DOCID:fr01au06-42]

DEPARTMENT OF COMMERCE

National Oceanic and Atmospheric Administration

[I.D. 050306A]

Small Takes of Marine Mammals Incidental to Specified Activities; Marine Geophysical Survey of the Western Canada Basin, Chukchi Borderland and Mendeleev Ridge, Arctic Ocean, July - August, 2006

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

ACTION: Notice; issuance of an incidental harassment authorization.

SUMMARY: In accordance with the Marine Mammal Protection Act (MMPA) regulations, notification is hereby given that NMFS has issued an Incidental Harassment Authorization (IHA) to University of Texas at Austin Institute for Geophysics (UTIG) for an Incidental Harassment Authorization (IHA) to take small numbers of marine mammals, by Level B Harassment, incidental to conducting a marine seismic survey in the Arctic Ocean from approximately July 15 - August 29, 2006.

DATES: Effective from July 15, 2006 through August 29, 2006.

ADDRESSES: A copy of the IHA and the application are available by writing to Michael Payne, Chief, Permits, Conservation, and Education Division, Office of Protected Resources, National Marine Fisheries Service, 1315 East-West Highway, Silver Spring, MD 20910-3225, or by telephoning the contact listed here. A copy of the application containing a list of references used in this document may be obtained by writing to this address, by telephoning the contact listed here (FOR FURTHER INFORMATION CONTACT) or online at: http://www.nmfs.noaa.gov/pr/permits/incidental.htm. Documents cited in this notice may be viewed,

by appointment, during regular business hours, at the aforementioned address.

FOR FURTHER INFORMATION CONTACT: Jolie Harrison, Office of Protected Resources, NMFS, (301) 713-2289, ext 166.

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

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

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

[Level B harassment] .

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

Summary of Request

On March 8, 2006, NMFS received an application from UTIG for the taking, by harassment, of several species of marine mammals incidental to conducting, with research funding from the National Science Foundation (NSF), a marine seismic survey in the Western Canada Basin, Chukchi Borderland and Mendeleev Ridge of the Arctic Ocean during July through August, 2006. The seismic survey will be operated in conjunction with a sediment coring project, which will obtain data regarding crustal structure. The purpose of this study is to collect seismic reflection and refraction data and sediment cores that reveal the crustal structure and composition of submarine plateaus in the western Amerasia Basin in the Arctic Ocean. Past studies have led many researchers to support the idea that the Amerasia Basin opened about a pivot point near the Mackenzie Delta. However, the crustal character of the Chukchi Borderlands could determine whether that scenario is correct, or whether more complicated tectonic scenarios must be devised to explain the presence of the Amerasia Basin. These data will assist in the determination of the tectonic evolution of the Amerasia Basin and Canada Basin which is fundamental to such basic concerns as sea level fluctuations and paleoclimate in the Mesozoic era.

Description of the Activity

The Healy, a U.S. Coast Guard (USCG) Cutter ice-breaker, will rendezvous with the science party off Barrow on or around 15 July. The Healy will then sail north and arrive at the beginning of the seismic survey, which will start >150 km (93 mi) north of Barrow. The cruise will last for approximately 40 days, and it is estimated that the total seismic survey time will be approximately 30 days depending on ice conditions. Seismic survey work is scheduled to terminate west of Barrow about 25 August. The vessel will then sail south to Nome where the science party will disembark.

The seismic survey and coring activities will take place in the Arctic Ocean. The overall area within which the seismic survey will occur is located approximately between 71[deg]36' and 79[deg]25' N., and between 151[deg]57' E. and

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177[deg]24' E. The bulk of the seismic survey will not be conducted in any country's territorial waters. The survey will occur within the Exclusive Economic Zone (EEZ) of the U.S. for approximately 563 km (350 mi).

The Healy will use a portable Multi-Channel Seismic (MCS) system to conduct the seismic survey. A cluster of eight airguns will be used as the energy source during most of the cruise, especially in deep water areas. The airgun array will have four 500-in\3\ Bolt airguns and four 210-in\3\ G. guns for a total discharge volume of 2840 in\3\. In shallow water, occurring during the first and last portions of the cruise, a four 105 in\3\ GI gun array with a total discharge volume of 420 in3 will be used. Other sound sources (see below) will also be employed during the cruise. The seismic operations during the survey will be used to obtain information on the history of the ridges and basins that make up the Arctic Ocean.

The Healy will also tow a hydrophone streamer 100-150 m (328-492 ft) behind the ship, depending on ice conditions. The hydrophone streamer will be up to 200 m (656 ft) long. As the source operates along the survey lines, the hydrophone receiving system will receive and record the returning acoustic signals. In addition to the hydrophone streamer, sea ice seismometers (SIS) will be deployed on ice floes ahead of the ship using a vessel-based helicopter, and then retrieved from behind the ship once it has passed the SIS locations. SISs will be deployed as much as 120 km (74 mi) ahead of the ship, and recovered when as much as 120 km (74 mi) behind the ship. The seismometers will be placed on top of ice floes with a hydrophone lowered into the water through a small hole drilled in the ice. These instruments will allow seismic refraction data to be collected in the heavily ice-covered waters of the region.

The program will consist of a total of approximately 3625 km (2252 mi) of surveys, not including transits when the airguns are not operating, plus scientific coring at least seven locations. Water depths within the study area are 40-3858 m (131-12,657 ft). Little more than 8 percent of the survey (approximately 300 km (186 mi)) will occur in water depths The empirical data indicate that, for deep water (>1000 m), the L-DEO model tends to overestimate the received sound levels at a given distance (Tolstoy et al., 2004a,b). However, to be precautionary pending acquisition of additional empirical data, UTIG will use the values predicted by L-DEO's modeling in deep water, after conversion from SEL to rms (Table 1).

Empirical measurements were not conducted for intermediate depths (100-1000 m). On the expectation that results would be intermediate between those from shallow and deep water, a 1.5 correction factor is applied to the estimates provided by the model for deep water situations

Empirical measurements were not made for the 4 GI guns that will be employed during the proposed survey in shallow water (200 dB re 1 microPa) before exhibiting aversive behaviors. With the presently-planned source, such levels would be found within approximately 400 m (1,312 ft) of the 4 GI guns operating in shallow water.

Odontocete reactions to large arrays of airguns are variable and, at least for small odontocetes, seem to be confined to a smaller radius than has been observed for mysticetes. UTIG proposed using a 170-dB acoustic threshold for behavioral disturbance of delphinids and pinnipeds in lieu of the 160-dB NMFS currently uses as the standard threshold. However, NMFS does not believe there is enough data to support changing the threshold at this time and will utilize the 160 dB safety radii. NMFS is currently developing new taxa-specific acoustic criteria and they are scheduled to be made available to the public within the next two years.

Pinnipeds: Pinnipeds are not likely to show a strong avoidance reaction to the medium-sized airgun sources that will be used. Visual monitoring from seismic vessels has shown only slight (if any) avoidance of airguns by pinnipeds, and only slight (if any) changes in behavior-see Appendix A (e) of the application. Those studies show that pinnipeds frequently do not avoid the area within a few hundred meters of operating airgun arrays (e.g., Miller et al., 2005; Harris et al., 2001). However, initial telemetry work suggests that avoidance and other behavioral reactions to small airgun sources may at times be stronger than evident to date from visual studies of pinniped reactions to airguns (Thompson et al., 1998). Even if reactions of the species occurring in the present study area are as strong as those evident in the telemetry study, reactions are expected to be confined to relatively small distances and durations, with no long-term effects on pinniped individuals or populations. Hearing Impairment and Other Physical Effects

Temporary or permanent hearing impairment is a possibility when marine 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. Current NMFS practice regarding exposure of marine mammals to high-level sounds is to establish mitgation that will avoid cetaceans and pinnipeds exposure to impulsive sounds 180 and 190 dB re 1 Pa (rms), respectively (NMFS, 2000). Those criteria have been used in defining the safety (shut down) radii planned for UTIG's seismic survey. As summarized here,

The 180 dB criterion for cetaceans may be lower than necessary to avoid temporary threshold shift (TTS), let alone permanent auditory injury, at least for belugas and delphinids.

The minimum sound level necessary to cause permanent hearing impairment is higher, by a variable and generally unknown amount, than the level that induces barely-detectable TTS.

The level associated with the onset of TTS is often considered to be a level below which there is no danger of permanent damage.

NMFS is presently developing new noise exposure criteria for marine mammals that account for the now-available scientific data on TTS and other relevant factors in marine and terrestrial mammals.

Several aspects of the required monitoring and mitigation measures for this project are designed to detect marine mammals occurring near the airguns (and multi-beam bathymetric sonar), and to avoid exposing them to sound pulses that might, at least in theory, cause hearing impairment (see Mitigation). In addition, many cetaceans are likely to show some avoidance of the area with high received levels of airgun sound (see above). 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 might 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, as discussed below, there is no definitive evidence that any of these effects occur even for marine mammals in close proximity to large arrays of airguns and beaked whales do not occur in the present study area. It is unlikely that any effects of these types would occur during the present project given the brief duration of exposure of any given mammal, and the planned monitoring and mitigation measures (see below). The following subsections discuss in somewhat more detail the possibilities of TTS, permanent threshold shift (PTS), and non-auditory physical effects.

TTS: TTS is the mildest form of hearing impairment that can occur during exposure to a strong sound (Kryter, 1985). While experiencing TTS, the hearing threshold rises and a sound must be stronger in order to be heard. TTS can last from minutes or hours to (in cases of strong TTS) days. For sound exposures at or somewhat above the TTS threshold, hearing sensitivity recovers rapidly after exposure to the noise ends. Few data on sound levels and durations necessary to elicit mild TTS have been obtained for marine mammals, and none of the published data concern TTS elicited by exposure to multiple pulses of sound.

For toothed whales exposed to single short pulses, the TTS threshold appears to be, to a first approximation, a function of the energy content of the pulse (Finneran et al., 2005, 2002). Given the available data, the received level of a single seismic pulse might need to be approximately 210 dB re 1 Pa rms (approximately 221-226 dB pk-pk) in order to produce brief, mild TTS. Exposure to several seismic pulses at received levels near 200-205 dB (rms) might result in slight TTS in a small odontocete, assuming the TTS threshold is (to a first approximation) a function of the total received pulse energy. Seismic pulses with received levels of 200-205 dB or more are usually restricted to a radius of no more than 200 m around a seismic vessel operating a large array of airguns.

For baleen whales, there are no data, direct or indirect, on levels or properties of sound that are required to induce TTS. However, no cases of TTS are expected given the moderate size of the source, and the strong likelihood that baleen whales would avoid the approaching airguns (or vessel) before being exposed to levels high enough for there to be any possibility of TTS.

In pinnipeds, TTS thresholds associated with exposure to brief pulses (single or multiple) of underwater sound have not been measured. Initial evidence from prolonged exposures suggested that some pinnipeds may incur TTS at somewhat lower received levels than do small odontocetes exposed for similar durations (Kastak et al., 1999; Ketten et al., 2001; cf. Au et al., 2000).

A marine mammal within a radius of 100 m (328 ft) around a typical large array of operating airguns might be exposed to a few seismic pulses with levels of 205 dB, and possibly more pulses if the mammal moved with the

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seismic vessel. The sound level radius would be similar (100 m) around the 8-airgun array while surveying in intermediate depths (100-1000 m). This would occur for ``Ramping up'' (soft start) is standard operational protocol during startup of large airgun arrays. Ramping up involves starting the airguns in sequence, usually commencing with a single airgun and gradually adding additional airguns. This practice will be employed when either airgun array is operated.

It is unlikely that cetaceans would be exposed to airgun pulses at a sufficiently high level for a sufficiently long period to cause more than mild TTS, given the relative movement of the vessel and the marine mammal. In this project, most of the seismic survey will be in deep water where the radius of influence and duration of exposure to strong pulses is smaller.

With a large array of airguns, TTS would be most likely in any odontocetes that bow-ride or otherwise linger near the airguns. In the present project, the anticipated 180-dB distances in deep and intermediate-depth water are 716 m (2,349 ft) and 1074 m (3,524 ft), respectively, for the 8-airgun gun system (Table 1) and 246 m (840 ft) and 369 m (1,207 ft), respectively for the 4-GI gun system. The waterline at the bow of the Healy will be approximately 123 m (404 ft) ahead of the airgun. However, no species that occur within the project area are expected to bow-ride.

The predicted 180 and 190 dB distances for the airguns operated by UTIG vary with water depth. They are estimated to be 716 m (2,349 ft) and 230 m (754 ft), respectively, in deep water for the 8-airgun system, and 246 m (807 ft) and 75 m (246 ft), respectively, in deep water for the 4-GI gun system. In intermediate depths, these distances are predicted to increase to 1074 m (3,523 ft) and 345 m (1,131 ft), respectively for the 8-airgun system, and 369 m (1,210 ft) and 113 m (371 ft), respectively for the 4-GI gun system. The predicted 180 and 190 dB distances for the 4-GI gun system in shallow water are 1822 m (5,978 ft) and 938 m (3,077 ft), respectively (Table 1). The 8-airgun array will not be operated in shallow water. Shallow water (150 m (492 ft). Belugas within 250 m (820 ft) of stationary helicopters on the ice with the engine running showed the most overt reactions (Patenaude et al., 2002). Whales were observed to make only minor changes in direction in response to sounds produced by helicopters, so all reactions to helicopters were considered brief and minor. Cetacean reactions to helicopter disturbance are difficult to predict and may range from no reaction at all to minor changes in course or (infrequently) leaving the immediate area of the activity. Pinnipeds

Few systematic studies of pinniped reactions to aircraft overflights have been completed. Documented reactions range from simply becoming alert and raising the head to escape behavior such as hauled out animals rushing to the water. Ringed seals hauled out on the surface of the ice have shown behavioral responses to aircraft overflights with escape responses most probable at lateral distances 170 dB re 1 microPa (rms), hearing impairment is also unlikely at an SPL as low as 190 dB. Therefore, it is unlikely that marine mammals will be harmed as a result of continuing seismic into periods of poor visibility in Arctic waters.

Regarding source reduction, UTIG elected to use a much smaller array during the portion of the study that occurs across the area where cetaceans are more likely to be encountered and where oil and gas surveys could potentially be operating in the same area. Additionally, UTIG suggested, and NMFS adopted, expanded powerdown and shutdown radii, which effectively reduce the source level whenever marine mammals are in the area.

Comment 9: CBD states that harassment of marine mammals can occur at levels below the 160 dB threshold for Level B harassment, and that NMFS should reassess its harassment thresholds for acoustic impacts. To support this recommendation, the commenter cites the fact that bowhead whales have been shown to exhibit avoidance of seismic airguns at 120 dB and that harbor porpoises have been reported to avoid a broad range of sounds at very low SPLs, between 100 and 140 dB.

Response: As discussed in reference to bowhead whale reactions, NMFS does not believe that all types of avoidance necessarily rise to the level of MMPA harassment.

The 160-dB rms isopleth is based on work by Malme et al. (1984) for migrating gray whales along the California coast. Clark et al. (2000), replicating the work by Malme et al. (1984), indicated that this response is context dependent, as gray whales did not respond to simulated airgun noise when the acoustic source was removed from the gray whale migratory corridor. This indicates to NMFS that establishing a 160-dB isopleth for estimating a safety zone for low-frequency hearing specialists when exposed to a low frequency source is conservative. For mid- or high-frequency hearing specialists, a 160-dB ZOI for a low-frequency source is likely overly conservative.

Bowhead whale avoidance of airguns at 120 dB is an important consideration in any MMPA authorization in as much as it could affect the ability of subsistence whalers to effectively hunt bowheads, however, in this case the activity is scheduled to take place hundreds of kilometers from land and before the bowhead migration comes through, so subsistence hunting is not a concern.

Comment 10: One commenter states that the preparation of an EIS is necessary pursuant to NEPA, especially considering the increased controversy that has arisen.

Response: NMFS has addressed all of the NEPA significance criteria in our Finding of No Significant Impact (FONSI), which may be viewed at our website. (See ADDRESSES)

Comment 11: CBD asserts that, based on the NMFS stock assessment reports, the population status of several of the species (such as ringed seals, bearded seals, and spotted seals) addressed in the IHA is unknown. They say that without this information, NMFS cannot make a negligible impact determination.

Response: NMFS acknowledges that there are some gaps in the data available on some Arctic species, however, NMFS uses the best data available to do our analyses. For example, ringed seal density was based on survey data from 1999 and 2000. The ratio used to calculate bearded seal data from ringed seal data was from was based on data gathered in 1990 and 1991. However, actual bearded seal density surveyed in 1999 and 2000 was 5 to 10 times less than the number used here, but that number was not used because the surveyor was unable to correct for missed animals. Though NMFS has a responsibility to use the best available science and to be precautionary in the absence of data, the MMPA does not mandate that NMFS deny authorizations until newer data are available.

Comment 12: The marine mammal commission recommended that 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 be attributed to the applicant's activities.

Response: NMFS will incorporate this recommendation into the IHA.

Comment 13: One commenter suggests that NMFS should further consider the possibility bubble growth in marine mammals as a result of airgun pulses.

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Response: Both the EA and the IHA application include a discussion of bubble growth. It is possible that certain marine mammal species (i.e., beaked whales) may be especially susceptible to injury and/or stranding when exposed to strong pulsed sounds. However, as discussed in the EA and application, there is no definitive evidence that any of these effects occur even for marine mammals in close proximity to large arrays of airguns, and beaked whales do not occur in the present study area. Additionally, it is unlikely that any effects of these types would occur during the present project given the brief duration of exposure of any given mammal, and the required monitoring and mitigation measures.

Comment 14: The MMC recommended that NMFS revise its interpretation of TTS to indicate that it has the potential to injure marine mammals and therefore constitutes Level a Harassment.

Response: TTS may be considered to be an adaptive process (analogous to the dark adaptation in visual systems) wherein sensory cells change their response patterns to sound. Tissues are not irreparably damaged with the onset of TTS, the effects are temporary (particularly for onset-TTS), and NMFS does not believe that this effect qualifies as an injury. Therefore TTS-onset is treated as of Level B Harassment.

Comment 15: The CBD argues that the effects of this action are significant under NEPA and that, therefore, an EIS is required. Additionally, CBD suggests that it is illegal for NMFS to authorize an activity covered by an EA when NSF has announced their intent to do an EIS (as argued in Humane Society v. Department of Commerce (DOC) (05- 1392).

Response: NMFS does not believe that the effects of this action are significant pursuant to NEPA and refers the commenter to NMFS' Finding of No Significant Impact, where we have addressed the NEPA significance criteria.

Further, NMFS disagrees that HSUS v. DOC precludes reliance on the EA and FONSI for the Healy's seismic survey and IHA. In HSUS v. DOC, the court concluded that the FONSI was deficient (for reasons explained in the court's opinion), and therefore an EIS was required; the court did not say that the fact that an EIS is in the process of development per se precludes any action until the EIS is complete.

Comment 16: The MMC recommends that the NMFS, in consultation with the applicant, the affected Native communities, the Minerals Management Service, NSF and other interested parties, identify and establish long- term monitoring programs needed to confirm that the proposed seismic surveys and anticipated future oil and gas-related activities do not cause changes in the seasonal distribution patterns, abundance, or productivity of marine mammal populations in the area.

Response: Both NMFS and NSF recognize the importance of long-term monitoring in the Arctic and will work towards this end whenever possible. Specifically though, as discussed in previous comments, Sections 101(a)(5)(A) and (D) of the MMPA do not address cumulative effects and therefore it is not appropriate to require the applicant, through the IHA, to participate in a long-term monitoring program for that reason.

Comment 17: NMFS' proposed IHA requires that the 180 dB isopleth around the sound source be free of marine mammals for 30 minutes before ramp-up may commence. UTIG suggests that only the 190-dB radius needs to be clear of marine mammals prior to start up because bowheads and belugas have been shown to avoid seismic anyway and are expected to move beyond the 180-dB radius during the ramp-up and because pinnipeds (to which the 190-dB radius applies) have not shown much avoidance of operating seismic in the Beaufort Sea will not move out of the safety zone during a ramp-up anyway.

Response: NMFS uses the 180-dB isopleth as an appropriate precautionary area around the sound source to clear prior to the start- up of the airguns. NMFS is currently working on developing acoustic criteria, based in part on more taxa-specific data, and will revisit this issue upon their completion.

Comment 18: UTIG proposed expanded safety radii wherein they would not begin a ramp-up in shallow or intermediate depth water unless an area with radius at least 2 km has been visible to the observers and no cetaceans have been observed for 30 minutes, and wherein they would shut down if a cetacean was spotted at any range. However, during the comment period UTIG noted that for the single operating airguns, the 180 and 190 dB radii are much smaller than for the 4- or 8-gun sources. Thus, the lack of a power down option in shallow and intermediate water depths is conservative beyond necessity and limits research.

Response: NMFS generally agrees with NSF and has made minor modifications to the safety radii that were in the proposed IHA (see Table 1). The safety radii and their associated shutdown and powerdown criteria for the large airgun array and for pinnipeds remain the same as in the proposed IHA.

However, for the smaller airgun array, regarding cetaceans, the shutdown criteria have changed. Whereas the proposed IHA indicated that when in shallow or intermediate depth water the Healy would cease operating the smaller airgun array any time a cetacean was seen at any distance (which means 2 to 3 kilometers), the final IHA will require that the Healy powerdown airguns whenever a cetacean is sighted at any distance, and shut down at the distances indicated in Table 1, which are still significantly larger than the isopleths suggested by the model and initially proposed as safety radii by UTIG.

NSB Comments on Specific Pages of the Federal Register Notice of the Proposed IHA

Comment 19: In the proposed IHA on Page 27998, 1st column, Description of Activity: The first paragraph of this section states that seismic activity will begin at a distance greater than 93 miles north of Barrow. The next paragraph goes on to state that the seismic area will occur at about 71[deg]36'N. Barrow is approximately 71[deg]14' N. The difference between these two latitudes is on the order of 20 miles and not 93. Why the discrepancy?

Response: The Healy cruise will begin approximately 93 miles north of Barrow, however, it ends southwest of the starting point. The area delineated by the indicated latitude and longitude includes both the starting and ending point.

Comment 20: In the proposed IHA on Page 27999, 2nd and 3rd columns, Safety Radii: Modeling attenuation rates of seismic sounds in the Arctic based on empirical data collected in the Gulf of Mexico has considerable limitations. Sea ice will likely play a major role in the attenuation rates of sounds in the northern Chukchi Sea. Sea ice could cause seismic sounds to propagate much farther than expected. Empirical data need to be collected to verify the models and safety radii must be adjusted accordingly.

Response: UTIG's original application proposed safety radii based on the Gulf of Mexico, however, for the reasons stated in the above comment UTIG and NMFS decided to use expanded precautionary safety radii to implement powerdowns and shutdowns.

Comment 21: The proposed IHA states that most encounters with marine mammals will ``occur in low numbers and most encounters for most species will occur within 100 km of shore.'' This statement is not supported by data. There have been few surveys of marine

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mammal distribution or abundance in the planned activity area. The studies used for estimating the densities of marine mammals in the study area are not well suited for estimating takes. The seismic activities of the Healy will be conducted in the sea ice, whereas most of the surveys referenced are in open water situations. As a result of the lack of data regarding the density of certain species in the pack ice, some of the take estimates in the proposed IHA are low, and some are high. Satellite tracking of beluga whales (Suydam et al. 2005), indicates that large numbers of belugas may be encountered at the shelf break or in deep waters of the Arctic Basin. Spotted seals takes are also very low. Considerable numbers of spotted seals could be encountered on the south reaching leg of the seismic surveys. Estimates for belugas and spotted seals appear to be too low.

Response: NMFS appreciates the input from local biologists regarding potential encounters with the affected species during the Healy cruise. Accordingly, NMFS has increased the authorized take of beluga whales from 134 to 200, and take of spotted seals from 5 to 25. This change does not affect our negligible impact determination.

Estimated Take by Incidental Harassment for the Eastern Tropical Pacific Seismic Survey

All anticipated takes would be ``takes by harassment'', as described previously, involving temporary changes in behavior. In the sections below, we describe methods to estimate ``take by harassment'' and present estimates of the numbers of marine mammals that might be affected during the proposed seismic study in the Arctic Ocean. The estimates are based on data obtained during marine mammal surveys in and near the Arctic Ocean by Stirling et al. (1982), Kingsley (1986), Koski and Davis (1994), Moore et al. (2000a), and Moulton and Williams (2003), and on estimates of the sizes of the areas where effects could potentially occur. In some cases, these estimates were made from data collected from regions and habitats that differed from the proposed project area. Adjustments to reported population or density estimates were made on a case by case basis to take into account differences between the source data and the general information on the distribution and abundance of the species in the project area. This section provides estimates of the number of potential ``exposures'' to sound levels equal or greater than 160 dB.

Although several systematic surveys of marine mammals have been conducted in the southern Beaufort Sea, few data (systematic or otherwise) are available on the distribution and numbers of marine mammals in the northern Chukchi and Beaufort Seas or offshore water of the Arctic Ocean. The main sources of distributional and numerical data used in deriving the estimates are described in detail in UTIG's application. There is some uncertainty about how representative those data are and the assumptions used below to estimate the potential ``take by harassment''. However, the approach used here seems to be the best available at this time.

The following estimates are based on a consideration of the number of marine mammals that might be harassed by approximately 3624 line kilometers (2,251 mi) of seismic surveys across the Arctic Ocean. An assumed total of 4530 km (2,815 mi) of trackline includes a 25-percent allowance over and above the planned approximately 3624 km (2,251 mi) to allow for turns, lines that might have to be repeated because of poor data quality, or for minor changes to the survey design.

As noted above, there is some uncertainty about how representative the data are and assumptions used in the calculations. To provide some allowance for the uncertainties, ``maximum estimates'' as well as ``best estimates'' of exposures have been derived (Table 1). For a few marine mammal species, several density estimates were available, and in those cases, the mean and maximum estimates were calculated from the survey data. When the seismic survey area is on the edge of the range of a species, we used the available mammal survey data as the maximum estimate and assumed that the average density along the seismic trackline will be approximately 0.10 times the density from the available survey data. The assumed densities are believed to be similar to, or in most cases higher than, the densities that will actually be encountered during the survey.

The anticipated radii of influence of the bathymetric sonar, sub- bottom profiler, and pinger are less than those for the airgun configurations. NMFS assumes that, during simultaneous operations of all the airgun array, sonar, and profiler, any marine mammals close enough to be affected by the sonars would already be affected by the airguns. The pinger will operate only during coring while the airguns are not in operation. However, whether or not the airguns are operating simultaneously with the sonar, profiler or pinger, marine mammals are expected to exhibit no more than short-term and inconsequential responses to the sonar, profiler or pinger given their characteristics (e.g., narrow downward-directed beam) and other considerations described previously. Such reactions are not considered to constitute ``taking'' and, therefore, no additional allowance is included for animals that might be affected by the sound sources other than the airguns.

The potential number of occasions when members of each species might be exposed to received levels of 160 dB re 1 microPa (rms) was calculated for each of three water depth categories (1000 m (>3,280 ft)) within the two survey areas (south of 75[deg] N. ``near Barrow'' and north of 75[deg] N. ``polar pack'') by multiplying

The expected species density, either ``average'' (i.e., best estimate) or ``maximum'', corrected as described above,

The anticipated line-kilometers of operations with both the 4-GI and 8-airgun array in each water-depth category after applying a 25 percent allowance for possible additional line kilometers as noted earlier,

The cross-track distances within which received sound levels are predicted to be 160 dB for each water-depth category (2 X the 160 dB safety radii).

Unlike other species whose ``best'' and ``maximum'' density estimates were multiplied by the entire trackline within each of the two portions of the project area (``near Barrow'' and ``polar pack'') to estimate exposures, gray whale and walrus densities were only multiplied by the proposed seismic trackline in water depths 150 km (93 mi) north of the Alaska coast is highly unlikely. Adult fish near seismic operations are likely to avoid the source, thereby avoiding injury. No EFH species will be present as very early life stages when they would be unable to avoid seismic exposure that could otherwise result in minimal mortality.

The proposed Arctic Ocean seismic program for 2006 is predicted to have negligible to low physical effects on the various life stages of fish and invertebrates for its approximately 40 day duration and 3625- km (2,252-mi) extent and will not result in any permanent impact on habitats used by marine mammals, or to the food sources they use. Nonetheless, the main impact issue associated with the proposed activities will be temporarily elevated noise levels and the associated direct effects on marine mammals, as discussed above.

During the seismic study only a small fraction of the available habitat would be ensonified at any given time. Disturbance to fish species would be short-term and fish would return to their pre- disturbance behavior once the seismic activity ceases. Thus, the proposed survey would have little, if any, impact on the abilities of marine mammals to feed in the area where seismic work is planned.

Some mysticetes, including bowhead whales, feed on concentrations of zooplankton. Although the main summering area for bowheads is in the Canadian Beaufort Sea, at least a few feeding bowhead whales may occur in offshore waters of the western Beaufort Sea and northern Chukchi Sea in July and August, when the Healy will be in the area. A reaction by zooplankton to a seismic impulse would only be relevant to whales if it caused a concentration of zooplankton to scatter. Pressure changes of sufficient magnitude to cause that type of reaction would probably occur only very close to the source. Impacts on zooplankton behavior are predicted to be negligible, and that would translate into negligible impacts on feeding mysticetes.

Thus, the proposed activity is not expected to have any habitat- related effects that could cause significant or long-term consequences for individual marine mammals or their populations, since operations at the various sites will be limited in duration.

Potential Effects on Subsistence Use of Marine Mammals

Subsistence hunting and fishing continue to be prominent in the household economies and social welfare of some Alaskan residents, particularly among those living in small, rural villages (Wolfe and Walker, 1987). Subsistence remains the basis for Alaska Native culture and community. In rural Alaska, subsistence activities are often central to many aspects of human existence, including patterns of family life, artistic expression, and community religious and celebratory activities. The National Science Foundation offers guidelines for science coordination with native Alaskans at http://www.arcus.org/guidelines/ .

Marine mammals are legally hunted in Alaskan waters near Barrow by coastal Alaska Natives; species hunted include bowhead whales, beluga whales, ringed, spotted, and bearded seals, walrus, and polar bears. In the Barrow area, bowhead whales provided approximately 69 percent of the total weight of marine mammals harvested from April 1987 to March 1990. During that time, ringed seals were harvested the most on a numerical basis (394 animals).

Bowhead whale hunting is the key activity in the subsistence economies of Barrow and two smaller communities to the east, Nuiqsut and Kaktovik. The whale harvests have a great influence on social relations by strengthening the sense of Inupiat culture and heritage in addition to reinforcing family and community ties.

An overall quota system for the hunting of bowhead whales was established by the International Whaling Commission in 1977. The quota is now regulated through an agreement between NMFS and the Alaska Eskimo Whaling Commission (AEWC). The AEWC allots the number of bowhead whales that each whaling community may harvest annually (USDI/BLM 2005).

The community of Barrow hunts bowhead whales in both the spring and fall during the whales' seasonal migrations along the coast. Often, the bulk of the Barrow bowhead harvest is taken during the spring hunt. However, with larger quotas in recent years, it is common for a substantial fraction of the annual Barrow quota to remain available for the fall hunt. The communities of Nuiqsut and Kaktovik participate only in the fall bowhead harvest. The spring hunt at Barrow occurs after leads open due to the deterioration of pack ice; the spring hunt typically occurs from early April until the first week of June. The fall migration of bowhead whales that summer in the eastern Beaufort Sea typically begins in late August or September. The location of the fall subsistence hunt depends on ice conditions and (in some years)

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industrial activities that influence the bowheads movements as they move west (Brower, 1996). In the fall, subsistence hunters use aluminum or fiberglass boats with outboards. Hunters prefer to take bowheads close to shore to avoid a long tow during which the meat can spoil, but Braund and Moorehead (1995) report that crews may (rarely) pursue whales as far as 80 km. The autumn hunt at Barrow usually begins in mid-September, and mainly occurs in the waters east and northeast of Point Barrow. The whales have usually left the Beaufort Sea by late October (Treacy, 2002a,b).

The scheduling of this seismic survey has been discussed with representatives of those concerned with the subsistence bowhead hunt, most notably the AEWC and the Barrow Whaling Captains' Association,. For this among other reasons, the project has been scheduled to commence in mid-July and terminate approximately 25 August, before the start of the fall hunt at Barrow (or Nuiqsut or Kaktovik), to avoid possible conflict with whalers.

Although the timing of the Healy's seismic survey may overlap with potential subsistence harvest of beluga whales, ringed seals, spotted seals, or bearded seals, the hunting takes place well inshore of the proposed survey, which is to start > 150 km (93 mi) offshore and terminate > 200 km (124 mi) offshore.

Providing UTIG abides by the Plan of cooperation below, NMFS does not anticipate any unmitigable adverse impacts on the subsistence hunt of these species or stocks to result from the proposed Healy seismic survey.

Plan of Cooperation

UTIG and the AEWC have developed a ``Plan of Cooperation'' for the 2006 Arctic Ocean seismic survey, in consultation with representatives of the Barrow whaling community.

A Barrow resident knowledgeable about the mammals and fish of the area will be included as a member of the MMO team aboard the Healy. Although his primary duties will be as a member of the MMO team responsible for implementing the monitoring and mitigation requirements, he will also be able to act as liaison with hunters and fishers if they are encountered at sea. However, the proposed activity has been timed so as to avoid overlap with the main harvests of marine mammals (especially bowhead whales), and is not expected to affect the success of subsistence fishers.

The Plan of Cooperation covers the initial phases of UTIG's Arctic Ocean seismic survey planned to occur 15 July to 25 August. The purpose of this plan is to identify measures that will be taken to mitigate any adverse effects on the availability of marine mammals for subsistence uses, and to ensure good communication between the project scientists and the community of Barrow. The Healy will communicate with the shore via the Barrow Arctic Science Consortium or Search and Rescue in Barrow to know where hunters may be located to avoid them. The Healy's Helicopters receive flight path directions which are followed unless there is a human safety issue that prevents it. Once the ship is 20-25 miles north of Barrow, it is not considered in the zone of subsistence hunting for any village and is less of a concern.

As noted above, in the unlikely event that subsistence hunting or fishing is occurring within 5 km (3 mi) of the Healy's trackline, the airgun operations will be suspended until the Healy is The project is planned for July-August, when few bowhead whales are present and no bowhead hunting is occurring;

Airgun operations will be limited to offshore waters, far from areas where there is subsistence hunting or fishing, and in waters where marine mammal densities are generally low;

When operating in shallower parts of the study area, airgun operations will be limited to the smaller source (4 GI guns);

In addition to these mitigation measures that are built into the general design, several specific mitigation measures will be implemented to avoid or minimize effects on marine mammals encountered along the tracklines and are discussed below.

Vessel-based observers will monitor marine mammals near the seismic source vessel during all airgun operations. These observations will provide the real-time data needed to implement some of the key mitigation measures. When marine mammals are observed within, or about to enter, designated safety zones (see below) where there is a possibility of significant effects on hearing or other physical effects, airgun operations will be powered down (or shut down if necessary) immediately. Vessel-based observers will watch for marine mammals near the seismic vessel during all periods of shooting and for a minimum of 30 min prior to the planned start of airgun operations after an extended shut down. Due to the timing of the survey situated at high latitude, the project will most likely take place during continuous daylight and monitoring adjustments will not be necessary for nighttime (darkness).

In addition to monitoring, mitigation measures that will be adopted will include (1) speed or course alteration, provided that doing so will not compromise operational safety requirements, (2) power down or shut-down procedures, and (3) no start up of airgun operations unless the full 180 dB safety zone is visible for at least 30 min during day or night.

Speed or Course Alteration

If a marine mammal is detected outside the safety radius and, based on its position and the relative motion, is likely to enter the safety radius, the vessel's speed and/or direct course may, when practical and safe, be changed in a manner that also minimizes the effect on the planned science objectives. The marine mammal activities and movements relative to the seismic vessel will be closely monitored to ensure that the marine mammal does not approach within the safety radius. If the mammal appears likely to enter the safety radius, further mitigative actions will be taken, i.e., either further course alterations or power down or shut down of the airgun(s). However, in regions of complete ice cover, which are common north of 75[deg] N., cetaceans are unlikely to be encountered because they must reach the surface to breathe.

Power-down Procedures

A power-down involves decreasing the number of airguns in use such that the radius of the 180-dB zone is decreased to the extent that marine mammals are no longer within the 180-dB safety radius. A power down may also occur when the vessel is moving from one seismic line to another. During a power down, one airgun (or some other number of airguns less than the

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full airgun array) is operated. The continued operation of one airgun is intended to alert marine mammals to the presence of the seismic vessel in the area. In contrast, a shut down occurs when all airgun activity is suspended.

If a marine mammal is detected outside the safety radius but is likely to enter the safety radius, and if the vessel's speed and/or course cannot be changed to avoid having the mammal enter the safety radius, the airguns may (as an alternative to a complete shut down) be powered down before the mammal is within the safety radius. Likewise, if a mammal is already within the safety zone when first detected, the airguns will be powered down if the power-down results in the animal being outside of the 180-dB isopleth, else the airguns will be shut down. During a power-down of the 4- or 8-airgun array, one airgun (either a single 105 in3 GI gun or one 210 in3 G. gun, respectively) will be operated. If a marine mammal is detected within or near the smaller safety radius around that single airgun (see Table 2), it will be shut down as well (see next subsection).

Following a power-down, airgun activity will not resume until the marine mammal has cleared the safety zone. The animal will be considered to have cleared the safety zone if it: is visually observed to have left the safety zone; or has not been seen within the zone for 15 min in the case of small odontocetes and pinnipeds; or has not been seen within the zone for 30 min in the case of mysticetes (large odontocetes do not occur within the study area).

Shut-down Procedures

The operating airgun(s) will be shut down completely if a marine mammal approaches or enters the then-applicable safety radius and a power down is not practical or prescribed (see expanded safety radii in Table 1). The operating airgun(s) will also be shut down completely if a marine mammal approaches or enters the estimated safety radius around the source that would be used during a power down.

Expanded Safety Radii

After submitting their application, UTIG proposed expanded safety zones for shallow and intermediate depth water. As reflected in Table 1, while operating the small array (420 in3) in shallow or intermediate depth water, the Healy will powerdown airguns if a cetacean is seen at any distance from the vessel (most likely maximum visibility 2-3 km (1.2-1.9 mi)). While operating the 420 in\3\ array, the Healy will cease operating the airguns at the distances indicated in Table 1.

While the Healy is operating the large array (3940 in3) in intermediate depth water, they will shutdown airguns if a cetacean is seen at any distance from the ship.

For pinnipeds, in shallow water the Healy will implement a 1000-m (3,280-ft) shut-down zone, and for intermediate depth water, the Healy will implement a 500-m (1,640-ft) shut-down zone.

Ramp-up Procedures

A ``ramp-up'' procedure will be followed when the airgun array begins operating after a specified-duration period without airgun operations. NMFS normally requires that the rate of ramp up be no more than 6 dB per 5 min period. The specified period depends on the speed of the source vessel and the size of the airgun array that is being used. Ramp-up will begin with one of the G. guns (210 in\3\) or one of the Bolt airguns (500 in\3\) for the 8-airgun array, or one of the 105 in\3\ GI guns for the 4-GI gun array. One additional airgun will be added after a period of 5 minutes. Two more airguns will be added after another 5 min, and the last four airguns (for the 8-airgun array) will all be added after the final 5 min period. During the ramp-up, the safety zone for the full airgun array in use at the time will be maintained.

If the complete 180-dB safety radius has not been visible for at least 30 min prior to the start of operations, ramp up will not commence unless at least one airgun has been operating during the interruption of seismic survey operations. This means that it will not be permissible to ramp up the 4-GI gun or 8-airgun source from a complete shut down in thick fog or darkness (which may be encountered briefly in late August); when the outer part of the 180 dB safety zone is not visible. If the entire safety radius is visible, then start up of the airguns from a shut down may occur at night (if any periods of darkness are encountered during seismic operations). If one airgun has operated during a power-down period, ramp up to full power will be permissible in poor visibility, on the assumption that marine mammals will be alerted to the approaching seismic vessel by the sounds from the single airgun and could move away if they choose. Ramp up of the airguns will not be initiated during the day or at night if a marine mammal has been sighted within or near the applicable safety radii during the previous 15 or 30 min, as applicable.

Airgun activity will not resume until the marine mammal has cleared the safety radius. The animal will be considered to have cleared the safety radius if it is visually observed to have left the safety radius, or if it has not been seen within the radius for 15 min (small odontocetes and pinnipeds) or 30 min (mysticetes).

Helicopter flights

The use of a helicopter to deploy and retrieve SISs during the survey is expected, at most, to cause brief behavioral reactions of marine mammals. To limit disturbance to marine mammals, helicopters will follow the survey track line. UTIG will avoid landing within 1000 ft (304 m) of an observed marine mammal, and maintain a minimum altitude of 1000 ft (304 m), unless weather or other circumstances require a closer landing for human safety. For efficiency, each helicopter excursion will be scheduled to deploy/retrieve three or four SIS units. This will minimize the number of flights and the number of potential distubances to marine mammals in the area.

Monitoring

UTIG proposes to sponsor marine mammal monitoring during the present project, in order to implement the proposed mitigation measures that require real-time monitoring, and to satisfy the anticipated monitoring requirements of the IHA.

Vessel-based observers will monitor marine mammals near the seismic source vessel during all seismic operations. There will be little or no darkness during this cruise. Airgun operations will be shut down when marine mammals are observed within, or about to enter, designated safety radii. Vessel-based marine mammal observers (MMOs) will also watch for marine mammals near the seismic vessel for at least 30 min prior to the planned start of airgun operations after an extended shut down of the airgun. When feasible, observations will also be made during daytime periods without seismic operations (e.g., during transits and during coring operations).

During seismic operations in the Arctic Ocean, four MMOs will be based aboard the vessel. MMOs will be appointed by UTIG with NMFS' concurrence. A Barrow resident knowledgeable about the mammals and fish of the area is expected to be included as one of the team of marine mammal observers (MMOs) aboard the Healy. At least one MMO, and when practical, two MMOs, will monitor marine mammals near the seismic vessel during ongoing operations and nighttime start ups (if darkness is encountered in late August). Use of two simultaneous MMOs will increase the

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proportion of the animals present near the source vessel that are detected. MMO(s) will normally be on duty in shifts of duration no longer than 4 hours. The USCG crew will also be instructed to assist in detecting marine mammals and implementing mitigation requirements (if practical). Before the start of the seismic survey the crew will be given additional instruction on how to do so.

The Healy is a suitable platform for marine mammal observations. When stationed on the flying bridge, the eye level will be approximately 27.7 m (91 ft) above sea level, and the MMO will have an unobstructed view around the entire vessel. If surveying from the bridge, the MMO's eye level will be 19.5 m (64 ft) above sea level and approximately 25[deg] of the view will be partially obstructed directly to the stern by the stack (Haley and Ireland, 2006). The MMO(s) will scan the area around the vessel systematically with reticle binoculars (e.g., 7 50 Fujinon), Big-eye binoculars (25 150), and with the naked eye. During any periods of darkness (minimal, if at all, in this cruise), NVDs will be available (ITT F500 Series Generation 3 binocular-image intensifier or equivalent), if and when required. The survey will take place at high latitude in the summer when there will be continuous daylight, but night (darkness) is likely to be encountered briefly at the southernmost extent of the survey in late August. Laser rangefinding binoculars (Leica LRF 1200 laser rangefinder or equivalent) will be available to assist with distance estimation; these are useful in training observers to estimate distances visually, but are generally not useful in measuring distances to animals directly.

To assure prompt implementation of shut downs, additional channels of communication between the MMOs and the airgun technicians will be established in 2006 as compared with the arrangements on the Healy in 2005 (cf. Haley and Ireland, 2006). During power downs and shut downs, the MMO(s) will continue to maintain watch to determine when the animal(s) are outside the safety radius. Airgun operations will not resume until the animal is outside the safety radius. The animal will be considered to have cleared the safety radius if it is visually observed to have left the safety radius, or if it has not been seen within the radius for 15 min (small odontocetes and pinnipeds) or 30 min (mysticetes).

All observations and airgun power or shut downs will be recorded in a standardized format. Data will be entered into a custom database using a notebook computer. The accuracy of the data entry will be verified by computerized validity data checks as the data are entered and by subsequent manual checking of the database. These procedures will allow initial summaries of data to be prepared during and shortly after the field program, and will facilitate transfer of the data to statistical, graphical, or other programs for further processing and archiving.

Results from the vessel-based observations will provide

1. The basis for real-time mitigation (airgun power or shut down).

2. Information needed to estimate the number of marine mammals potentially taken by harassment, which must be reported to NMFS (behavior when disturbed, etc).

3. Data on the occurrence, distribution, and activities of marine mammals in the area where the seismic study is conducted.

4. Information to compare the distance and distribution of marine mammals relative to the source vessel at times with and without seismic activity.

5. Data on the behavior and movement patterns of marine mammals seen at times with and without seismic activity.

Reporting

A report will be submitted to NMFS within 90 days after the end of the cruise. The report will describe the operations that were conducted and the marine mammals that were detected near the operations. The report will be submitted to NMFS, providing full documentation of methods, results, and interpretation pertaining to all monitoring. The 90-day report will summarize the dates and locations of seismic operations, and all marine mammal sightings (dates, times, locations, activities, associated seismic survey activities). The report will also include estimates of the amount and nature of the impacts on marine mammals resulting from the seismic survey. Analysis and reporting conventions will be consistent with those for the 2005 Healy cruise to factilitate comparisons and (where appropriate) pooling of data across the two seasons.

Endangered Species Act

Pursuant to section 7 of the ESA, the National Science Foundation (NSF) has consulted with NMFS on this proposed seismic survey. NMFS has also consulted internally pursuant to Section 7 of the ESA on the issuance of an IHA under section 101(a)(5)(D) of the MMPA for this activity. In a Biological Opinion (BO), NMFS concluded that the 2006 UTIG seismic survey in the Arctic Ocean and the issuance of the associated IHA are not likely to jeopardize the continued existence of threatened or endangered species or destroy or adversely modify any designated critical habitat. NMFS has issued an incidental take statement (ITS) for bowhead whales that contains reasonable and prudent measures with implementing terms and conditions to minimize the effects of this take. The terms and conditions of the BO have been incorporated into the UTIG IHA.

National Environmental Policy Act (NEPA)

NSF prepared an Environmental Assessment of a Marine Geophysical Survey by the USCG Healy of the Western Canada Basin, Chukchi Borderland and Mendeleev Ridge, Arctic Ocean, July-August 2006. NMFS has adopted this EA and issued a Finding of No Significant Impact.

Conclusions

NMFS has determined that the impact of conducting the seismic survey in the Arctic Ocean may result, at worst, in a temporary modification in behavior (Level B Harassment) of small numbers, relative to the population sizes, of certain species of marine mammals. The maximum estimates of take indicate that no more than 2.5 percent of the gray whale, ringed seal, and spotted seal populations would be harassed, and no more than 1 percent of any of the other affected stocks. This activity is expected to result in a negligible impact on the affected species or stocks.

To summarize the reasons stated previously in this document, this preliminary determination is supported by: (1) the likelihood that, given sufficient notice through slow ship speed and ramp-up, marine mammals are expected to move away from a noise source that is annoying prior to its becoming potentially injurious; (2) recent research that indicates that TTS is unlikely (at least in delphinids) until levels closer to 200-205 dB re 1 microPa are reached rather than 180 dB re 1 microPa; (3) the fact that 200-205 dB isopleths would be well within 100 m (328 ft) of the vessel; and (4) the likelihood that marine mammal detection ability by trained observers is close to 100 percent during daytime and remains high at night to that distance from the seismic vessel. As a result, no take by injury or death is anticipated, and the potential for temporary or permanent hearing impairment is very low and will be avoided through the incorporation of the proposed mitigation measures mentioned in this document.

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While the number of potential incidental harassment takes will depend on the distribution and abundance of marine mammals in the vicinity of the survey activity, the number of potential harassment takings is estimated to be small, and has been mitigated to the lowest level practicable through incorporation of the measures mentioned previously in this document.

The proposed seismic program will not interfere with any legal subsistence hunts, since seismic operations will not be conducted in the same space and time as the hunts in subsistence whaling and sealing areas. Therefore, NMFS believes the issuance of an IHA for this activity will not have an unmitigable adverse effect on the availability of any marine mammal species or stocks for subsistence purposes.

Authorization

As a result of these determinations, NMFS proposes to issue an IHA to UTIG for conducting a seismic survey in the Arctic Ocean from July 15 - August 25, 2006, provided the previously mentioned mitigation, monitoring, and reporting requirements are incorporated.

Dated: July 26, 2006. James H. Lecky, Director, Office of Protected Resources, National Marine Fisheries Service.

[FR Doc. 06-6616 Filed 7-31-06; 8:45 am]

BILLING CODE 3510-22-S