# Marine Mammals; Incidental Take During Specified Activities > Briefs, arguments, decisions, and more. URL: https://www.frixlaw.com/law-library/documents/fr%3AE8-12918 ## Record - **Collection:** Federal Register - **Document type:** Rule - **Published:** June 11, 2008 - **Citation:** 73 FR 33212 ## Text DEPARTMENT OF THE INTERIOR Fish and Wildlife Service 50 CFR Part 18 [FWS-R7-FHC-2008-0040; 71490-1351-0000-L5] RIN 1018-AU41 Marine Mammals; Incidental Take During Specified Activities AGENCY: Fish and Wildlife Service, Interior. ACTION: Final rule. SUMMARY: The Fish and Wildlife Service (Service or we) has developed regulations that authorize the nonlethal, incidental, unintentional take of small numbers of Pacific walruses ( Odobenus rosmarus divergens ) and polar bears ( Ursus maritimus ) during oil and gas industry (Industry) exploration activities in the Chukchi Sea and adjacent western coast of Alaska. This rule will be effective for 5 years from date of issuance. We find that the total expected takings of Pacific walruses (walruses) and polar bears during Industry exploration activities will impact small numbers of animals, will have a negligible impact on these species, and will not have an unmitigable adverse impact on the availability of these species for subsistence use by Alaska Natives. The regulations include: permissible methods of nonlethal taking; measures to ensure that Industry activities will have the least practicable adverse impact on the species and their habitat, and on the availability of these species for subsistence uses; and requirements for monitoring and reporting. The Service will issue Letters of Authorization (LOAs) to conduct activities under the provisions of these regulations. DATES: This rule is effective June 11, 2008, and remains effective through June 11, 2013. We find that it is appropriate to make this rule effective immediately because it relieves restrictions that would otherwise apply under the Marine Mammal Protection Act and therefore section 553(d)(1) of the Administrative Procedure Act applies. FOR FURTHER INFORMATION CONTACT: Craig Perham, Office of Marine Mammals Management, U.S. Fish and Wildlife Service, 1011 East Tudor Road, Anchorage, AK 99503, telephone 907-786-3810 or 1-800-362-5148, or e-mail R7_MMM_Comment@fws.gov . SUPPLEMENTARY INFORMATION: Background Section 101(a)(5)(A) of the Marine Mammal Protection Act (MMPA) (16 U.S.C. 1371(a)(5)(A)) gives the Secretary of the Interior (Secretary) through the Director of the Service (we) the authority to allow the incidental, but not intentional, taking of small numbers of marine mammals, in response to requests by U.S. citizens (you) [as defined in 50 CFR 18.27(c)] engaged in a specified activity (other than commercial fishing) in a specified geographic region. According to the MMPA, we shall allow this incidental taking if (1) we make a finding that the total of such taking for the 5-year regulatory period will have no more than a negligible impact on these species and will not have an unmitigable adverse impact on the availability of these species for taking for subsistence use by Alaska Natives, and (2) we issue regulations that set forth (i) permissible methods of taking, (ii) means of effecting the least practicable adverse impact on the species and their habitat and on the availability of the species for subsistence uses, and (iii) requirements for monitoring and reporting. If we issue regulations allowing such incidental taking, we can issue LOAs to conduct activities under the provisions of these regulations when requested by citizens of the United States. The term ”take,” as defined by the MMPA, means to harass, hunt, capture, or kill, or attempt to harass, hunt, capture, or kill any marine mammal. Harassment, as defined by the MMPA, for activities other than military readiness activities or scientific research conducted by or on behalf of the Federal Government, means “any act of pursuit, torment, or annoyance which (i) has the potential to injure a marine mammal or marine mammal stock in the wild” [the MMPA calls this 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” [the MMPA calls this Level B harassment] (16 U.S.C. 1362). The terms “small numbers,” “negligible impact,” and “unmitigable adverse impact” are defined in 50 CFR 18.27 (i.e., regulations governing small takes of marine mammals incidental to specified activities) as follows. “Small numbers” is defined as “a portion of a marine mammal species or stock whose taking would have a negligible impact on that species or stock.” “Negligible impact” is “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.” “Unmitigable adverse impact” means “an impact resulting from the specified activity: (1) That is likely to reduce the availability of the species to a level insufficient for a harvest to meet subsistence needs by (i) causing the marine mammals to abandon or avoid hunting areas, (ii) directly displacing subsistence users, or (iii) placing physical barriers between the marine mammals and the subsistence hunters; and (2) that cannot be sufficiently mitigated by other measures to increase the availability of marine mammals to allow subsistence needs to be met.” Industry conducts activities, such as oil and gas exploration, in marine mammal habitat that could result in the taking of marine mammals. Although Industry is under no legal requirement to obtain incidental take authorization, since 1991, Industry has requested, and we have issued regulations for, incidental take authorization for conducting activities in areas of walrus and polar bear habitat. We issued incidental take regulations for walruses and polar bears in the Chukchi Sea for the period 1991-1996 (56 FR 27443; June 14, 1991). In the Beaufort Sea, incidental take regulations have been issued from 1993 to present: November 16, 1993 (58 FR 60402); August 17, 1995 (60 FR 42805); January 28, 1999 (64 FR 4328); February 3, 2000 (65 FR 5275); March 30, 2000 (65 FR 16828); November 28, 2003 (68 FR 66744); and August 2, 2006 (71 FR 43926). These regulations are at 50 CFR part 18, subpart J (§§ 18.121-18.129). Summary of Current Request On August 5, 2005, the Alaska Oil and Gas Association (AOGA), on behalf of its members, (Agrium Kenai Nitrogen Operations, Alyeska Pipeline Service Company, Anadarko Petroleum Corporation, BP Exploration (Alaska) Inc., Chevron, Eni Petroleum, ExxonMobil Production Company, Flint Hills Resources, Alaska, Forest Oil Corporation, Marathon Oil Company, Petro-Canada (Alaska) Inc., Petro Star Inc., Pioneer Natural Resources Alaska, Inc., Shell Exploration & Production Company, Tesoro Alaska Company, and XTO Energy, Inc.) requested that the Service issue regulations to allow the nonlethal, incidental take of small numbers of walruses and polar bears in the Chukchi Sea for a period of 5 years. The Service requested additional information from AOGA regarding the nature, scope, and location of proposed activities for its analysis of potential impacts on walruses, polar bears, and subsistence harvests of these resources. On November 22, 2006, Shell Offshore Inc. (SOI) provided an addendum to the AOGA petition describing SOI's projected activities for 2007-2012. On January 2, 2007, AOGA, on behalf of its members, also provided an addendum to its original petition referencing a Draft Environmental Impact Statement prepared by the Minerals Management Service (MMS) for the Chukchi Sea Planning Area: Oil and Gas Lease Sale 193 and Seismic Surveying Activities in the Chukchi Sea (Chukchi Sea DEIS). The Chukchi Sea DEIS included estimates of all reasonably foreseeable oil and gas activities associated with proposed Outer Continental Shelf (OCS) lease sales in the Chukchi Sea Planning Area. The AOGA petition requested that the Service consider activities described in the Chukchi Sea DEIS for the period 2007-2012. On January 2, 2007, ConocoPhillips Alaska, Inc. (CPAI), also provided an addendum to the original AOGA petition describing CPAI's projected activities from 2007-2012. The petition and addendums are available at: (Alaska.fws.gov/fisheries/mmm/itr.htm). The Chukchi Sea DEIS, referenced in the AOGA petition, has subsequently been finalized and is available at http://www.mms.gov/alaska/ref/EIS%20EA/Chukchi_feis_Sale193/feis_193.htm (OCS EIS/EA MMS 2007-026). The combined requests are for regulations to allow the incidental, nonlethal take of small numbers of walruses and polar bears in association with oil and gas activities in the Chukchi Sea and adjacent coastline projected out to the year 2012. The information provided by the petitioners indicates that projected oil and gas activities over this timeframe will be limited to exploration activities. Development and production activities were not considered in the requests. The petitioners have also specifically requested that these regulations be issued for nonlethal take. The petitioners have indicated that, through the implementation of appropriate mitigation measures, they are confident that no lethal take will occur. Prior to issuing regulations in response to this request, we must evaluate the level of industrial activities, their associated potential impacts to walruses and polar bears, and their effects on the availability of these species for subsistence use. All projected exploration activities described by SOI, CPAI, and AOGA (on behalf of its members) in their petitions, as well as projections of reasonably foreseeable activities for the period 2007-2012 described in the Chukchi Sea EIS were considered in our analysis. The activities and geographic region specified in the requests, and considered in these regulations are described in the ensuing sections titled “Description of Geographic Region” and “Description of Activities.” Description of Regulations The regulations are limited to the nonlethal, incidental take of small numbers of walruses and polar bears associated with oil and gas exploration activities (geophysical seismic surveys, exploratory drilling, and associated support activities) in the Chukchi Sea and adjacent coast of Alaska and would be effective for a period of up to 5 years from the date of issuance. We assessed the geographic region, as outlined in the “Description of Geographic Region,” and the type of industrial activities, as outlined in the “Description of Activities” section. No development or production activities are anticipated over this timeframe, or included in the regulations. The total estimated level of activity covered by these regulations, as outlined in the “Description of Activities” section, was based on all projected exploration activities described by SOI, CPAI, and AOGA (on behalf of its members) in their petitions, as well as projections of reasonably foreseeable activities for the period 2007-2012 described in the Chukchi Sea EIS. If the level of activity is more than anticipated, such as additional support vessels or aircraft, more drilling units, or more miles of geophysical surveys, the Service must re-evaluate its findings to determine if they continue to be appropriate. It is important to note that these regulations do not authorize, or “permit,” the actual activities associated with oil and gas exploration in the Chukchi Sea. Rather, they will authorize the nonlethal incidental, unintentional take of small numbers of walruses and polar bears associated with those activities based on standards set forth in the MMPA. The MMS, the U.S. Army Corps of Engineers (COE), and the Bureau of Land Management (BLM) are responsible for permitting activities associated with oil and gas activities in Federal waters and on Federal lands. The State of Alaska is responsible for permitting activities on State lands and in State waters. The regulations include permissible methods of nonlethal taking, measures to ensure the least practicable adverse impact on the species and the availability of these species for subsistence uses, and requirements for monitoring and reporting. The process for nonlethal incidental take regulations will be that persons seeking taking authorization for particular projects must apply for an LOA to cover nonlethal take associated with specified exploration activities under the regulations. Each group or individual conducting Industry-related activity within the area covered by these regulations may request an LOA. A separate LOA is mandatory for each activity, (i.e., geophysical survey, seismic activity, and exploratory drilling operation). We must receive applications for LOAs at least 90 days before the activity is to begin. Applicants for LOAs must submit an Operations Plan for the activity, a polar bear interaction plan, and a site-specific marine mammal monitoring and mitigation plan to monitor the effects of authorized activities on walruses and polar bears. A report on all exploration and monitoring activities must be submitted to the Service within 90 days after the completed activity. Details of monitoring and reporting requirements are further described in “Potential Effects of Oil and Gas Industry Activities on Pacific Walruses and Polar Bears.” Depending upon the nature, timing, and location of a proposed activity, applicants may also have to develop a Plan of Cooperation (POC) with potentially affected subsistence communities to minimize interactions with subsistence users. The POC is further described in “Potential Effects of Oil and Gas Industry Activities on Subsistence Uses of Pacific Walruses and Polar Bears.” We will evaluate each request for an LOA based upon the specific activity and the specific location. Each authorization will identify allowable methods or conditions specific to that activity and location. For example, we will consider seasonal or location-specific restrictions to limit interactions between exploration activities and walrus aggregations, or interference with subsistence hunting activities. Individual LOAs will include monitoring and reporting requirements specific to each activity, as well as any measures necessary for mitigating impacts to these species and the subsistence use of these species. The granting of each LOA will be based on a determination that the total level of taking by all applicants in any one year is consistent with the estimated level used to make a finding of negligible impact and a finding of no unmitigable adverse impacts on the availability of the species or the stock for subsistence uses. We will publish in the Federal Register a notice of issuance of LOAs. More information on applying for and receiving an LOA can be found at 50 CFR 18.27(f). The status of polar bears range wide was reviewed for potential listing under the Endangered Species Act and was listed as threatened on May 15, 2008 (73 FR 28212). The Service conducted an intra-Service section 7 consultation for these regulations, which resulted in a “no jeopardy” conclusion and developed a process to incorporate section 7 consultations under the ESA into the established framework for processing LOAs. Description of Geographic Region These regulations will allow Industry operators to incidentally take small numbers of Pacific walruses and polar bears within the same area, hereafter referred to as the Chukchi Sea Region (Figure 1). The geographic area covered by the request is the continental shelf of the Arctic Ocean adjacent to western Alaska. This area includes the waters (State of Alaska and OCS waters) and seabed of the Chukchi Sea, which encompasses all waters north and west of Point Hope (68°20′20″ N, −166°50′40″ W, BGN 1947) to the U.S.-Russia Convention Line of 1867, west of a north-south line through Point Barrow (71°23′29″ N, −156°28′30″ W, BGN 1944), and up to 200 miles north of Point Barrow. The region includes that area defined as the MMS OCS oil and gas Lease Sale 193 in the Chukchi Sea Planning Area. The region also includes the terrestrial coastal land 25 miles inland between the western boundary of the south National Petroleum Reserve-Alaska (NPR-A) near Icy Cape (70°20′00″, −148°12′00″) and the north-south line from Point Barrow. The geographic region encompasses an area of approximately 90,000 square miles. This terrestrial region encompasses a portion of the Northwest and South Planning Areas of the NPR-A. It is noteworthy that the north-south line at Point Barrow is the western border of the geographic region in the Beaufort Sea incidental take regulations (71 FR 43926; August 2, 2006). Description of Activities This section reviews the types and scale of oil and gas activities projected to occur in the Chukchi Sea Region over the specified time period (2007-2012). This information is based upon information provided by the petitioners and referenced in the Chukchi Sea EIS. The Service has used these descriptions of activity as a basis for its findings. If requests for LOAs exceed the projected scope of activity analyzed under these regulations, the Service will reevaluate its findings to determine if they continue to be appropriate before further LOAs are issued. The Service does not know the specific locations where oil and gas exploration will occur over the proposed regulatory period. The location and scope of specific activities will be determined based on a variety of factors, including the outcome of future Federal and State oil and gas lease sales and information gathered through subsequent rounds of exploration discovery. The information provided by the petitioners indicates that offshore exploration activities will be carried out during the open water season to avoid seasonal pack ice. Onshore exploration activities are not expected to occur in the vicinity of known polar bear denning areas or coastal walrus haulouts. Incidental take regulations do not authorize the placement and location of Industry activities; they can only authorize incidental nonlethal take of walruses and polar bears. Allowing the activity at particular locations is part of the permitting process that is authorized by the lead permitting agency, such as the COE or BLM. The specific dates and durations of the individual operations and their geographic locations will be provided to the Service in detail when requests for LOAs are submitted. Oil and gas activities anticipated and considered in our analysis of incidental take regulations include: (1) Marine-streamer 3D and 2D seismic surveys; (2) high-resolution site-clearance surveys; (3) offshore exploration drilling; (4) onshore seismic exploration and exploratory drilling; (5) and the associated support activities for the afore-mentioned activities. Descriptions of these activities follow. Marine-Streamer 3D and 2D Seismic Surveys Marine seismic surveys are conducted to locate geological structures potentially capable of containing petroleum accumulations. Air guns are the typical acoustic (sound) source for 2-dimensional and 3-dimensional (2D and 3D, respectively) seismic surveys. An outgoing sound signal is created by venting high-pressure air from the air guns into the water to produce an air-filled cavity (bubble) that expands and contracts. A group of air guns is usually deployed in an array to produce a downward-focused sound signal. Air gun array volumes for both 2D and 3D seismic surveys are expected to range from 1,800-6,000 cubic inches (in 3 ). The air guns are fired at short, regular intervals, so the arrays emit pulsed rather than continuous sound. While most of the energy is focused downward and the short duration of each pulse limits the total energy into the water column, the sound can propagate horizontally for several kilometers. A 3D source array typically consists of two to three sub-arrays of six to nine air guns each, and is about 12.5-18 meters (m) long and 16-36 m wide. The size of the source-array can vary during the seismic survey to optimize the resolution of the geophysical data collected at any particular site. Vessels usually tow up to three source arrays, depending on the survey-design specifications. Most 3D operations use a single source vessel; however, in a few instances, more than one source vessel may be used. The sound-source level (zero-to-peak) associated with typical 3D seismic surveys ranges between 233 and 240 decibels at 1 meter (re 1 μPa at 1 m). The vessels conducting 3D surveys are generally 70-90 m (330-295 ft) long. Surveys are typically acquired at a vessel speed of approximately 8.3 km/hour (4.5 knots). Source arrays are activated approximately every 10-15 seconds, depending on vessel speed. The timing between outgoing sound signals can vary for different surveys to achieve the desired “shot point” spacing to meet the geological objectives of the survey; typical spacing is 25-37.5 m (27-41 yards) wide. The receiving arrays could include multiple (4-16) streamer-receiver cables towed behind the source array. Streamer cables contain numerous hydrophone elements at fixed distances within each cable. Each streamer can be 3-8 km (2-5 mi) long with an overall array width of up to 1,500 m (1,640 yards) between outermost streamer cables. Biodegradable liquid paraffin is used to fill the streamer and provide buoyancy. Solid/gel streamer cables also are used. The wide extent of this towed equipment limits both the turning speed and the area a vessel covers with a single pass over a geologic target. It is, therefore, common practice to acquire data using an offset racetrack pattern. Adjacent transit lines for a survey generally are spaced several hundred meters apart and are parallel to each other across the survey area. Seismic surveys are conducted day and night when ocean conditions are favorable, and one survey effort may continue for weeks or months, depending on the size of the survey. Data-acquisition is affected by the arrays towed by the survey vessel and weather conditions. Typically, data are only collected between 25 and 30 percent of the time (or 6-8 hours a day) because of equipment or weather problems. In addition to downtime due to weather, sea conditions, turning between lines, and equipment maintenance, surveys could be suspended to avoid interactions with biological resources. The MMS estimates that individual surveys could last between 20-30 days (with downtime) to cover a 322 km 2 (200 mi 2 ) area. Marine-streamer 2D surveys use similar geophysical-survey techniques as 3D surveys, but both the mode of operation and general vessel type used are different. The 2D surveys provide a less-detailed subsurface image because the survey lines are spaced farther apart, but they cover wider areas to image geologic structure on more of a regional basis. Large prospects are easily identified on 2D seismic data, but detailed images of the prospective areas within a large prospect can only be seen using 3D data. The 2D seismic-survey vessels generally are smaller than 3D-survey vessels, although larger 3D-survey vessels are also capable of conducting 2D surveys. The 2D source array typically consists of three or more sub-arrays of six to eight air gun sources each. The sound-source level (zero-to-peak) associated with 2D marine seismic surveys are the same as 3D marine seismic surveys (233-240 dB re 1 μPa at 1 m). Typically, a single hydrophone streamer cable approximately 8-12 km long is towed behind the survey vessel. The 2D surveys acquire data along single track lines that are spread more widely apart (usually several miles) than are track lines for 3D surveys (usually several hundred meters). Both 3D and 2D marine-streamer surveys require a largely ice-free environment to allow effective operation and maneuvering of the air gun arrays and long streamers. In the Chukchi Sea Region, the timing and areas of the surveys will be dictated by ice conditions. The data-acquisition season in the Chukchi Sea could start sometime in July and end sometime in early November. Even during the short summer season, there are periodic incursions of sea ice, so there is no guarantee that any given location will be ice free throughout the survey. Approximately 160,934 km (100,000 line-miles) of 2D seismic surveys already have been collected in the Chukchi Sea program area, so the MMS assumes that additional geophysical surveys will be primarily 3D surveys focusing on specific leasing targets surrounding OCS Lease Sale 193. The 3D surveys are likely to continue during the early phase of exploration when wells are drilled; however, the number of surveys is expected to decrease over time as data is collected over the prime prospects and these prospects are tested by drilling. Based upon information provided by the petitioners, and estimates prepared by the MMS in the Chukchi Sea EIS, the Service estimates that, in any given year during the specified timeframe (2007-2012), up to four seismic survey vessels could be operating simultaneously in the Chukchi Sea Region during the open water season. During the 2006 open water season, three seismic surveys were conducted, while only one seismic survey was conducted during the 2007 open-water season. Each seismic vessel is expected to collect between 3,200-14,500 km (2,000-9,000 linear miles) of seismic survey data. Seismic surveys are expected to occur in open water conditions between July 1 and November 30 each year. We estimate that each seismic survey vessel will be accompanied or serviced by one to three support vessels. Helicopters may also be used, when available, for vessel support and crew changes. High-Resolution Site-Clearance Surveys Based on mapping of the subsurface structures using 2D and 3D seismic data, several well locations may be proposed. Prior to drilling deep test wells, high-resolution site clearance seismic surveys and geotechnical studies will be necessary to examine the proposed exploration drilling locations for geologic hazards, archeological features, and biological populations. Site clearance and studies required for exploration will be conducted during the open water season before a drill rig is mobilized to the site. A typical operation consists of a vessel towing an acoustic source (air gun) about 25 m behind the ship and a 600-m streamer cable with a tail buoy. The source array usually is a single array composed of one or more air guns. A 2D high-resolution site-clearance survey usually has a single air gun, while a 3D high-resolution site survey usually tows an array of air guns. The ships travel at 5.6-6.5 km/hour (3-3.5 knots), and the source is activated every 7-8 seconds (or about every 12.5 m). All vessel operations are designed to be ultra-quiet, as the higher frequencies used in high-resolution work are easily masked by the vessel noise. Typical surveys cover one OCS block at a time. MMS regulations require information be gathered on a 300-by 900-m grid, which amounts to about 129 line kilometers of data per lease block. If there is a high probability of archeological resources, the north-south lines are 50 m apart and the 900 m remains the same. Including line turns, the time to survey a lease block is approximately 36 hours. Air gun volumes for high-resolution surveys typically are 90-150 in 3 , and the output of a 90-in 3 air gun ranges from 229-233 dB high-resolution re 1μPa at 1m. Air gun pressures typically are 2,000 psi (pounds per square inch), although they can be used at 3,000 psi for higher signal strength to collect data from deep in the subsurface. Based upon information provided by the petitioners, and estimates prepared by the MMS in the Chukchi Sea EIS, we estimate that during the specified timeframe (2007-2012), as many as six high-resolution site surveys may be carried out in any given year, with the majority of site surveys occurring in the latter part of the regulatory time period. Offshore Drilling Operations Considering water depth and the remoteness of this area, drilling operations are most likely to employ drill ships with ice-breaker support vessels. Water depths greater than 30 m (100 ft) and possible pack-ice incursions during the open-water season will preclude the use of bottom-founded platforms as exploration drilling rigs. Using drill ships allows the operator to temporarily move off the drill site if sea or ice conditions require it. Drilling operations are expected to range between 30 and 90 days at different well sites, depending on the depth to the target formation, difficulties during drilling, and logging/testing operations. Drill ships will operate only during the open-water season, where drifting ice can prevent their operation. A drill ship is secured over the drill site by deploying anchors on as many as ten to twelve mooring lines. The drill pipe is encased in a riser that compensates for the vertical wave motion. The blowout preventer (BOP) is typically located at the seabed in a hole dug below the ice-scour depth. BOP placement is an important safety feature enabling the drill ship to shut down operations and get underway rapidly without exposing the well. One or more ice management vessels (ice breakers) generally support drill ships to ensure ice does not encroach on operations. A barge and tug typically accompany the vessels to provide a standby safety vessel, oil spill response capabilities, and refueling support. Most supplies (including fuel) necessary to complete drilling activities are stored on the drill ship and support vessels. Helicopter servicing of drill ships can occur as frequently as 1-2 times/day. The abandonment phase is initiated if exploratory wells are not successful. In a typical situation, wells are permanently plugged (with cement) and wellhead equipment removed. The seafloor site is restored to some practicable, pre-exploration condition. Post-abandonment surveys are conducted to confirm that no debris remains following abandonment or those materials remain at the lease tract. The casings for delineation wells are either cut mechanically or with explosives during the process of well abandonment. The MMS estimates that exploration wells will average 2,438 m (8,000 ft), will use approximately 475 tons of dry mud, and produce 600 tons of dry rock cuttings. Considering the cost of synthetic drilling fluids now commonly used, the MMS assumes that most of the drilling mud will be reconditioned and reused. All of the rock cuttings will be discharged at the exploration site. Considering the relatively short open-water season in the Chukchi Sea (July-November), the MMS estimates that up to four wells could be started by one rig each drilling season. However, it is more likely that only one to two wells could be drilled, tested, and abandoned by one drill ship in any given season, leaving work on the other wells to the next summer season. A total of five exploration wells have been drilled on the Chukchi shelf, and the MMS estimates that 7 to 14 additional wells will be needed to discover and delineate a commercial field. Based upon information provided by the petitioners, and estimates prepared by the MMS in the Chukchi Sea EIS, we estimate that as many as three drill ships could be operating in the Chukchi Sea Region in any given year during the specified timeframe (2007-2012), with the majority of exploratory drilling occurring in the latter part of the regulatory time period. Each drill ship could drill up to four exploratory or delineation wells per season. Each drill ship is likely to be supported by one to two ice breakers, a barge and tug, one to two helicopter flights per day, and one to two supply ships per week. The operating season is expected to be limited to the open-water season July 1 to November 30. Onshore Seismic Exploration and Drilling CPAI's petition also describes conducting onshore seismic exploration and drilling over the next five years, including geotechnical site investigations, vibroseis, construction of ice pads, roads, and islands, and exploratory drilling. One of these activities is the Intrepid prospect, approximately 32 km (20 mi) south of Barrow. Geotechnical site investigations include shallow cores and soil borings to investigate soil conditions and stratigraphy. Geotechnical properties at select points may be integrated with seismic data to develop a regional model for predicting soil conditions in areas of interest. Vibroseis seismic operations are conducted both onshore and on nearshore ice using large trucks with vibrators that systematically put variable frequency energy into the earth. A minimum of 1.2 m (4 ft) of sea ice is required to support heavy vehicles used to transport equipment offshore for exploration activities. These ice conditions generally exist from January 1 until May 31. The exploration techniques are most commonly used on landfast ice, but they can be used in areas of stable offshore pack-ice. Multiple vehicles are normally associated with a typical vibroseis operation. One or two vehicles with survey crews move ahead of the operation and mark the source receiver points. Occasionally, bulldozers are needed to build snow ramps on the steep terrain or to smooth offshore rough ice within the site. A typical wintertime exploration seismic crew consists of 40-140 personnel. Roughly 75 percent of the personnel routinely work on the active seismic crew, with approximately 50 percent of those working in vehicles and the remainder outside laying and retrieving geophones and cables. With the vibroseis technique, activity on the surveyed seismic line begins with the placement of sensors. All sensors are connected to the recording vehicle by multi-pair cable sections. The vibrators move to the beginning of the line, and recording begins. The vibrators move along a source line, which is at some angle to the sensor line. The vibrators begin vibrating in synchrony via a simultaneous radio signal to all vehicles. In a typical survey, each vibrator will vibrate four times at each location. The entire formation of vibrators subsequently moves forward to the next energy input point (67 m (220 ft) in most applications) and repeats the process. In a typical 16-to 18-hour day, a survey will complete 6 to 16 linear km (4-10 mi) in a 2D seismic operation and 24 to 64 linear km (15-40 mi) in a 3D seismic operation. CPAI anticipates conducting between one and five vibroseis seismic programs onshore within the northwest NPR-A over the next 5 years. CPAI also anticipates developing vertical seismic profiles (VSPs) to calibrate seismic and well data. Typically, VSP operations are staffed by less than eight people. Four or five of the operators remain in the vehicles (vibrators) within 1.6 to 3.2 km (1 to 2 mi) of the rig, while the others are located at the rig. On Federal lands, CPAI estimates drilling three to six onshore wells within the next five years. Drilling will likely include both well testing and VSPs. Three onshore wells are proposed for the 2007/2008 season. Drilling operations will require an estimated 32-161 km (20-100 mi) of ice roads, 32-483 km (20-300 mi) of rolligon trails, one to four airfields approximately 1,500 m (5,000 ft) in length on lakes or tundra, rig storage on gravel, possibly at new sites in the Northwest NPR-A, one to five camps, and one to three rigs operating in a given year. Existing Mitigation Measures for Oil and Gas Exploration Activities Measures to mitigate potential effects of oil and gas exploration activities on marine mammal resources and subsistence use of those resources have been identified and developed through previous MMS lease sale National Environmental Policy Act (NEPA) review and analysis processes. The Chukchi Sea Final EIS (CS FEIS) ( http://www.mms.gov/alaska/ref/EIS%20EA/Chukchi_feis_Sale193/feis_193.htm (OCS EIS/EA MMS 2007-026) identifies several existing measures designed to mitigate potential effects of oil and gas exploration activities on marine mammal resources and subsistence use of those resources (CS FEIS, Sections II.B.3; II-B.5-24). All plans for OCS exploration activities will go through an MMS review and approval to ensure compliance with established laws and regulations. Operational compliance is enforced through the MMS on-site inspection program. The following MMS lease sale stipulations and mitigation measures will be applied to all exploration activities in the Chukchi Lease Sale Planning Area and the geographic region of the incidental take regulations. The Service has incorporated these MMS Lease sale mitigation measures into their analysis of impacts to Pacific walruses and polar bears in the Chukchi Sea. MMS lease sale stipulations that will help minimize Industry impacts to Pacific walruses and polar bears include: Oil Spill Prevention and Response In compliance with 30 CFR 254, Oil-Spill-Prevention and Response Plans and contingency actions must be prepared by lessees to address the prevention, detection, and cleanup of fuel and oil spills associated with exploration operations. Site-Specific Monitoring Program for Marine Mammal Subsistence Resources A lessee proposing to conduct exploration operations within traditional subsistence use areas will be required to conduct a site-specific monitoring program designed to assess when walruses and polar bears are present in the vicinity of lease operations and the extent of behavioral effects on these marine mammals due to their operations. This stipulation applies specifically to the communities of Barrow, Wainwright, Point Lay, and Point Hope. Site-specific monitoring programs will provide information about the seasonal distributions of walruses and polar bears. The information can be used to improve evaluations of the threat of harm to the species and provides immediate information about their activities, and their response to specific events. This stipulation is expected to reduce the potential effects of exploration activities on walruses, polar bears, and the subsistence use of these resources. This stipulation also contributes incremental and important information to ongoing walrus and polar bear research and monitoring efforts. Conflict Avoidance Mechanisms To Protect Subsistence-Harvesting Activities Through consultation with potentially affected communities, the lessee shall make every reasonable effort to assure that their proposed activities are compatible with marine mammal subsistence hunting activities and will not result in unreasonable interference with subsistence harvests. In the event that no agreement is reached between the parties, the lessee, the appropriate management agencies and co-management organizations, and any communities that could be directly affected by the proposed activity may request that the MMS assemble a group consisting of representatives from the parties specifically to address the conflict and attempt to resolve the issues before the MMS makes a final determination on the adequacy of the measures taken to prevent unreasonable conflicts with subsistence harvests. This lease stipulation will help reduce potential conflicts between subsistence hunters and proposed oil and gas exploration activities. This stipulation will help reduce noise and disturbance conflicts from oil and gas operations during specific periods, such as peak hunting seasons. It requires that the lessee meet with local communities and subsistence groups to resolve potential conflicts. The consultations required by this stipulation ensure that the lessee, including contractors, consult and coordinate both the timing and sighting of events with subsistence users. This stipulation has proven to be effective in the Beaufort Sea Planning Area in mitigating offshore exploration activities through the development of annual agreements between the Alaska Eskimo Whaling Commission and participating oil companies. Measures To Mitigate Seismic-Surveying Effects The measures summarized below are based on the protective measures in MMS' most recent marine seismic survey exploration permits and the recently completed Programmatic Environmental Assessment of Arctic Ocean OCS Seismic Surveys—2006 ( http://www.mms.gov/alaska/ref/pea_be.htm ). As stated in the MMS Programmatic Environmental Assessment, these protective measures will be incorporated in all MMS-permitted seismic activities. 1. Spacing of Seismic Surveys—Operators must maintain a minimum spacing of 15 miles between the seismic-source vessels for separate simultaneous operations. 2. Exclusion Zone—A 180/190-decibel (dB) isopleth-exclusion zone (also called a safety zone) from the seismic-survey-sound source shall be free of marine mammals, including walruses and polar bears, before the survey can begin and must remain free of mammals during the survey. The purpose of the exclusion zone is to protect marine mammals from Level A harassment. The 180-dB (Level A harassment injury) applies to cetaceans and walruses, and the 190-dB (Level A harassment-injury) applies to pinnipeds other than walruses and polar bears. 3. Monitoring of the Exclusion Zone—Trained marine mammal observers (MMOs) shall monitor the area around the survey for the presence of marine mammals to maintain a marine mammal-free exclusion zone and monitor for avoidance or take behaviors. Visual observers monitor the exclusion zone to ensure that marine mammals do not enter the exclusion zone for at least 30 minutes prior to ramp up, during the conduct of the survey, or before resuming seismic survey work after a shut down. Shut Down—The survey shall be suspended until the exclusion/safety zone is free of marine mammals. All observers shall have the authority to, and shall instruct the vessel operators to, immediately stop or de-energize the airgun array whenever a marine mammal is seen within the zone. If the airgun array is completely shut down for any reason during nighttime or poor sighting conditions, it shall not be re-energized until daylight or whenever sighting conditions allow for the zone to be effectively monitored from the source vessel and/or through other passive acoustic, aerial, or vessel-based monitoring. Ramp Up—Ramp up is the gradual introduction of sound from airguns to deter marine mammals from potentially damaging sound intensities and from approaching the specified zone. This technique involves the gradual increase (usually 5-6 dB per 5-minute increment) in emitted sound levels, beginning with firing a single airgun and gradually adding airguns over a period of at least 20-40 minutes, until the desired operating level of the full array is obtained. Ramp-up procedures may begin after observers ensure the absence of marine mammals for at least 30 minutes. Ramp-up procedures shall not be initiated at night or when monitoring the zone is not possible. A single airgun operating at a minimum source level can be maintained for routine activities, such as making a turn between line transects, for maintenance needs or during periods of impaired visibility (e.g., darkness, fog, high sea states), and does not require a 30-minute clearance of the zone before the airgun array is again ramped up to full output. Field Verification—Before conducting the survey, the operator shall verify the radii of the exclusion/safety zones within real-time conditions in the field. This provides for more accurate radii rather than relying on modeling techniques before entering the field. Field-verification techniques must use valid techniques for determining propagation loss. When moving a seismic-survey operation into a new area, the operator shall verify the new radii of the zones by applying a sound-propagation series. 4. Monitoring of the Seismic-Survey Area—Aerial-monitoring surveys or an equivalent monitoring program acceptable to the Service will be required through the LOA authorization process. Field verification of the effectiveness of any monitoring techniques may be required by the Service. 5. Reporting Requirements—Reporting requirements provide regulatory agencies with specific information on the monitoring techniques to be implemented and how any observed impacts to marine mammals will be recorded. In addition, operators must immediately report to Federal regulators any shut downs due to a marine mammal entering the exclusion zones and provide the regulating agencies with information on the frequency of occurrence and the types and behaviors of marine mammals (if possible to ascertain) entering the exclusion zones. 6. Temporal/Spatial/Operational Restrictions—Seismic-survey and associated support vessels shall observe an 805-m (0.5-mi) safety radius around walruses hauled-out onto land or ice. Aircraft shall be required to maintain a 305-m (1,000-ft) minimum altitude within 805 m (0.5 mi) of hauled-out walruses. 7. Seismic-survey operators shall notify MMS immediately in the event of any loss of cable, streamer, or other equipment that could pose a danger to marine mammals. These seismic mitigation measures will help reduce the potential for Level A Harassment of walruses and polar bears during seismic operations. The spatial separation of seismic operations will also reduce potential cumulative effects of simultaneous operations. The monitoring and reporting requirements will provide location-specific information about the seasonal distributions of walruses and polar bears. The additional information can be used to evaluate the future threat of harm to the species and also provides immediate information about their activities, and their response to specific events. Biological Information Pacific Walruses 1. Stock Definition and Range Pacific walruses are represented by a single stock of animals that inhabit the shallow continental shelf waters of the Bering and Chukchi seas. The population ranges across the international boundaries of the United States and Russia, and both nations share common interests with respect to the conservation and management of this species. The distribution of Pacific walruses varies markedly with the seasons. During the late winter breeding season, walruses are found in areas of the Bering Sea where open leads, polynyas, or areas of broken pack-ice occur. Significant winter concentrations are normally found in the Gulf of Anadyr, the St. Lawrence Island Polynya, and in an area south of Nunivak Island. In the spring and early summer, most of the population follows the retreating pack-ice northward into the Chukchi Sea; however, several thousand animals, primarily adult males, remain in the Bering Sea, utilizing coastal haul-outs, during the ice-free season. During the summer months, walruses are widely distributed across the shallow continental shelf waters of the Chukchi Sea. Significant summer concentrations are normally found in the unconsolidated pack-ice west of Point Barrow, and along the northern coastline of Chukotka, Russia, near Wrangel Island. As the ice edge advances southward in the fall, walruses reverse their migration and re-group on the Bering Sea pack-ice. Between 1975 and 1990, aerial surveys were carried out by the United States and Russia at five year intervals, producing population estimates of: 221,350 (1975); 246,360 (1980); 234,020 (1985); and 201,039 (1990). The estimates generated from these surveys are considered conservative abundance estimates and are not useful for detecting trends because walruses are found in large groups that are distributed in a non-uniform fashion. Efforts to survey the Pacific walrus population were suspended after 1990 due to unresolved problems with survey methods to address the patchy distribution of walruses and that resulted in population estimates with unacceptably large confidence intervals. In the spring of 2006, a joint U.S./Russia aerial survey to estimate the walrus population was carried out in the pack ice of the Bering Sea. This information is currently being analyzed and a current population estimate is expected in the near future. Estimating the abundance or population size of Pacific walruses has been an inherently problematic task. Previous efforts conducted in the autumn (1975, 1980, 1985, and 1990) resulted in widely varying estimates with high variance and low confidence limits. Accounting for animals using traditional haul-outs is factored into the abundance estimates. The 1975, 1980, and 1985 walrus surveys predominatly found animals over sea ice habitat. In contrast, the 1990 survey included a large number of walruses located on land haul-outs, predominantly in Russia, during a season of extreme ice recession. A 1975 evaluation of aerial survey methods conducted in the U.S. sector over the eastern half of the Chukchi Sea (5 days of effort covering 7,743 km and 30.2 flight hours) found walruses were unevenly distributed, patchy, and encountered more frequently in ice habitat where at least 75 percent of the surface was covered by ice. Estimates of abundance, based on single day density estimates, ranged from 818 to 1,760 walruses in the open-water area, and 2,475 to 100,568 walruses in pack ice sampled areas. In 1980, a coordinated U.S. and Russian aerial survey found walruses located throughout the area surveyed and the U.S. distribution showed extreme clustering of walruses on pack ice in an area of high density between longitude 166° W and 171° W. Initially the estimates were 140,000 animals in the U.S. and 130,000 to 150,000 animals in Russia, with a final total estimate of 246,360 animals. In 1985, the third joint walrus survey found few walruses in the U.S. sector east of 161° or west of 170°. On days when more walruses were in the water, they were found farther into the pack ice, and on days when nearly all walruses were hauled out on the ice, they were close to the southern edge of the ice. The estimate of abundance for the U.S. portion of the survey was 63,487 animals with an additional 15,238 animals, mainly males, estimated in Bristol Bay, far to the south. The Russians estimated either 54,080 or 115,531 walruses in the pack ice of their sector, depending on the inclusion or exclusion of a large aggregation of walruses encountered on survey transects from the abundance estimate. This illustrates the symptomatic nature of clustered or patchy distributions of walruses noted earlier and the consequence on abundance estimates. In addition, the Russians counted 39,572 animals on their Bering Sea land haul-outs. The combined U.S. and Russia estimate was 234,020 animals. In 1990, a fourth joint survey was designed to employ a common survey design. Unlike other surveys, the study area was unexpectedly characterized by an extreme amount of open water caused by an unusual recession of pack ice. As a result, the survey covered land haul-outs in the U.S. and Russia as well as open water and pack ice. The total combined population estimate was 201,039. Of this total, the U.S. sector was comprised of 7,522 walruses in Bristol Bay haul-outs and only 16,489 estimated in the Chukchi Sea area. This estimate differs dramatically from previous pack ice estimates in the U.S. Chukchi Sea region, where walruses were relatively abundant in previous surveys. The vast majority of walruses were located in the Russian sector (154,225 walruses) and occupied land haul-outs, including 112,848 animals on Wrangel Island. Land haul-outs in Kamchatka, Southern Chukotka, the Gulf of Anadyr, and the north shore of Chukotka accounted for the remaining 41,377 animals. The Russian pack ice was remarkably sparse with an estimate of only 16,484 animals. 2. Habitat Walruses are an ice dependent species. They rely on floating pack-ice as a substrate for resting and giving birth. Walruses generally require ice thicknesses of 50 centimeters (cm) or more to support their weight. Although walruses can break through ice up to 20 cm thick, they usually occupy areas with natural openings and are not found in areas of extensive, unbroken ice. Thus, their concentrations in winter tend to be in areas of divergent ice flow or along the margins of persistent polynyas. Concentrations in summer tend to be in areas of unconsolidated pack-ice, usually within 100 km of the leading edge of the ice pack. When suitable pack-ice is not available, walruses haul out to rest on land. Isolated sites, such as barrier islands, points, and headlands, are most frequently occupied. Social factors, learned behavior, and proximity to their prey base are also thought to influence the location of haul-out sites. Traditional walrus haul-out sites in the eastern Chukchi Sea include Cape Thompson, Cape Lisburne, and Icy Cape. In recent years, the Cape Lisburne haul-out site has seen regular use in late summer. Numerous haul-outs also exist along the northern coastline of Chukotka, and on Wrangel and Herald islands, which are considered important haul-out areas in late summer, especially in years when the pack-ice retreats beyond the continental shelf. Notably, during the 1990 population survey, when the Chukchi Sea was largely ice-free, large haul-outs of walruses (over 100,000 animals) formed on Wrangel Island. In contrast, walruses observed during the 1970 though 1985 aerial surveys were seen primarily on sea ice over the continental shelf between Wrangel Island and Alaska. Although capable of diving to deeper depths, walruses are for the most part found in shallow waters of 100 m or less, possibly because of higher productivity of their benthic foods in shallower water. They feed almost exclusively on benthic invertebrates although Native hunters have also reported incidences of walruses preying on seals. Prey densities are thought to vary across the continental shelf according to sediment type and structure. Preferred feeding areas are typically composed of sediments of soft, fine sands. The juxtaposition of ice over appropriate depths for feeding is especially important for females with dependent calves that are not capable of deep diving or long exposure in the water. The mobility of the pack-ice is thought to help prevent walruses from overexploiting their prey resource. Although walruses may range some distance from land or ice haul-outs, for example during migrations or foraging excursions, the species is not adapted to a pelagic existence. Foraging trips can sometimes last up to several days, during which time they dive to the bottom nearly continuously. Most foraging dives to the bottom last between 5 and 10 minutes, with a relatively short (1-2 minute) surface interval. 3. Life History Walruses are long-lived animals with low rates of reproduction. Females reach sexual maturity at 4 to 9 years of age. Males become fertile at 5 to 7 years of age; however, they are usually unable to compete for mates until they reach full physical maturity at 15-16 years of age. Breeding occurs between January and March in the pack-ice of the Bering Sea. Calves are usually born in late April or May the following year during the northward migration from the Bering Sea to the Chukchi Sea. Calving areas in the Chukchi Sea extend from the Bering Strait to latitude 70 °N. Calves are capable of entering the water shortly after birth, but tend to haul-out frequently, until their swimming ability and blubber layer are well developed. Newborn calves are tended closely. They accompany their mother from birth and are usually not weaned for 2 years or more. Cows brood neonates to aid in their thermoregulation, and carry them on their back or under their flipper while in the water. Females with newborns often join together to form large “nursery herds”. Summer distribution of females and young walruses is closely tied to the movements of the pack-ice relative to feeding areas. Females give birth to one calf every 2 or more years. This reproductive rate is much lower than other pinniped species; however, some walruses live to age 35-40, and remain reproductively active until relatively late in life. Walruses are extremely social and gregarious animals. They tend to travel in groups and haul-out onto ice or land in groups. Walruses spend approximately one-third of their time hauled out onto land or ice. Hauled-out walruses tend to lie in close physical contact with each other. Youngsters often lie on top of the adults. The size of the hauled-out groups can range from a few animals up to several thousand individuals. 4. Mortality Polar bears are known to prey on walrus calves, and killer whales ( Orcinus orca ) have been known to take all age classes of animals. Predation levels are thought to be highest near terrestrial haul-out sites where large aggregations of walruses can be found; however, few observations of killer whales preying on walruses exist. Pacific walruses have been hunted by coastal Natives in Alaska and Chukotka for thousands of years. Exploitation of the Pacific walrus population by Europeans has also occurred in varying degrees since first contact. Presently, walrus hunting in Alaska and Chukotka is restricted to meet the subsistence needs of aboriginal peoples. Over the past decade, the combined harvest of the United States and Russia has averaged approximately 5,500 walruses per year. This mortality estimate includes corrections for under-reported harvest and struck and lost animals. Intraspecific trauma is also a known source of injury and mortality. Disturbance events can cause walruses to stampede into the water and have been known to result in injuries and mortalities. The risk of stampede-related injuries increases with the number of animals hauled out. Calves and young animals at the perimeter of these herds are particularly vulnerable to trampling injuries. 5. Distributions and Abundance of Pacific Walruses in the Chukchi Sea Walruses are seasonably abundant in the Chukchi Sea. Their distribution in the region is influenced primarily by the distribution and extent of seasonal pack-ice. In May and June walruses migrate into the region along lead systems that form along the coastlines of Alaska and Chukotka. During the summer months walruses are widely distributed along the southern margin of the seasonal pack-ice both in U.S. and Russian waters. During August, the edge of the pack-ice generally retreats northward to about 71 °N, but in light ice years, the ice edge can retreat beyond 76 °N. The sea ice normally reaches its minimum (northern) extent in September. In recent years, several tens of thousands of walruses have been reported congregating at coastal haul-outs along the Russian coast in late summer. Russian biologists attribute the formation of these coastal aggregations to diminishing sea ice habitats in offshore regions. In 2007, a new sea ice minima record was established. Sea ice had completely retreated from the continental shelf waters of the Chukchi Sea by mid-August, 2007 and anecdotal reports from Russia indicate that as many as 100,000 walruses, comprised of mixed herds of females and calves, congregated at coastal haul-outs along the northern Chukotka coastline. An estimated 2,000 to 5,000 walruses were also observed along the Alaskan Chukchi Sea coast in 2007 using nontraditional haul-outs. This is a relatively small portion of the annual, hauled-out animals in the population. Historically, approximately 5,000 animals have annually used the Bristol Bay haul-outs, such as Round Island and Cape Seniavin. The pack-ice usually advances rapidly southward in October, and most walruses move into the Bering Sea by mid-to-late November. Walrus are closely associated with sea ice. The dynamic nature of sea ice habitats is expected to result in considerable seasonal and annual variation in the number of animals likely to be present in the proposed exploration arena. While a recent abundance estimate for the number of walruses likely to be present in the offshore waters of the eastern Chukchi Sea during the proposed exploration season is not available, an aerial survey was carried out in the fall of 1990 during a season of minimum ice conditions where sea ice retracted north beyond the continental shelf, similar to recent conditions throughout the Chukchi Sea. This survey observed 16,489 walruses distributed along the Chukchi Sea pack-ice between Wrangel Island and Point Barrow, where a much larger portion of the population was distributed in Russia on land and sea ice haul-outs. The sea ice was distributed well beyond the continental shelf at the time of the survey and most walruses were using coastal haul-outs in Russia, which is similar to the pattern of distribution observed in 2007. Polar Bears 1. Alaska Stock Definition and Range Polar bears occur throughout the Arctic. The world population estimate of polar bears ranges from 20,000-25,000 individuals. In Alaska, they have been observed as far south in the eastern Bering Sea as St. Matthew Island and the Pribilof Islands. However, they are most commonly found within 180 miles of the Alaskan coast of the Chukchi and Beaufort seas, from the Bering Strait to the U.S./Canada border. Two stocks occur in Alaska: (1) The Chukchi-Bering seas stock (CS); and (2) the Southern Beaufort Sea stock (SBS). A summary of the Chukchi and Southern Beaufort Sea polar bear stocks is described below. A detailed description of the Chukchi Sea and Southern Beaufort Sea polar bear stocks can be found in the “Range-Wide Status Review of the Polar Bear ( Ursus maritimus )” ( http://alaska.fws.gov/fisheries/mmm/polarbear/issues.htm ). A. Chukchi/Bering Seas Stock (CS) The CS is defined as those polar bears inhabiting the area as far west as the eastern portion of the Eastern Siberian Sea, as far east as Point Barrow, and extending into the Bering Sea, with its southern boundary determined by the extent of annual ice. Based upon telemetry studies, the western boundary of the population has been set near Chaunskaya Bay in northeastern Russia. The eastern boundary is at Icy Cape, Alaska, which was, until recently, also considered to be the western boundary of the SBS. This eastern boundary constitutes a large overlap zone with bears in the SBS population. The CS population appeared to increase after the level of harvest was reduced in 1972. However, harvest records suggest that the population now may be declining. Illegal polar bear hunting in Russia is thought to be one reason for this decline. The most recent population estimate for the CS population is 2,000 animals. This was based on extrapolation of aerial den surveys from the early 1990s; however, this estimate is currently considered to be of little value for management. Reliable estimates of population size based upon mark and recapture are not available for this region and measuring the population size remains a research challenge due to the movements of the polar bear and the dynamic Arctic habitat. Legal harvesting activities for the CS stock are currently restricted to Native Alaskans in western Alaska, as long as this does not affect the sustainability of the polar bear population. In Alaska, average annual harvest levels declined by approximately 50 percent between the 1980s and the 1990s and have remained at low levels in recent years. We believe there are several factors affecting the harvest level of CS bears in western Alaska. Substantial illegal harvest in Chukotka is the most relevant factor affecting the CS population level. In recent years a reportedly sizable illegal harvest has occurred in Russia, despite a ban on hunting that has been in place since 1956. In addition, other factors such as climatic change and its effects on pack-ice distribution, as well as changing demographics and hunting effort in Native communities could influence the population and the declining take. The unknown rate of illegal take makes a stable designation for the CS population uncertain and tentative. Until recently, the United States and Russia have managed the shared CS polar bear population independently. Now, Alaska and Russian bear researchers and managers are working to update and enhance the collective knowledge of polar bears in the CS stock to improve management goals and objectives. On September 21, 2007, the United States ratified the U.S./Russia Bilateral Polar Bear Conservation Agreement (Bilateral Agreement) for the shared polar bear population, which had been signed by both countries on October 16, 2000; implementing legislation for the agreement occurred in January 2007. The purpose of the Bilateral Agreement is to assure long-term, science-based conservation of the polar bear population and includes binding harvest limits. Implementation of the Bilateral Agreement will unify management regimes and provide for harvest limits. The treaty calls for the active involvement of Native people and their organizations in future management programs. It will also enhance such long-term joint efforts as conservation of ecosystems and important habitats, harvest allocations based on sustainability, collection of biological information, and increased consultation and cooperation with state, local, and private interests. In association with the ratification of the agreement, the Service sponsored a meeting from August 7 through 9, 2007, of technical specialists from the United States and Russia to discuss future management, research, and conservation needs for the CS polar bear population. The goals of the meeting were to exchange information about current and future research activities and priorities, provide technical input concerning research and management needs for the implementation of the Bilateral Agreement with specific regard to field research and conservation practices, and to initiate planning for managing the subsistence harvest in Alaska and Russia under the newly activated treaty. The primary challenge discussed by the group is the lack of population information (status and trends) to support determination of a sustainable harvest as called for by the Bilateral Agreement. Information from this meeting will be shared at the first meeting of the Joint Commissioners. B. Southern Beaufort Sea (SBS) The SBS polar bear population is shared between Canada and Alaska. Radio-telemetry data, combined with earlier tag returns from harvested bears, suggested that the SBS region comprised a single population with a western boundary near Icy Cape, Alaska, and an eastern boundary near Pearce Point, Northwest Territories, Canada. Early estimates from the mid 1980s suggested the size of the SBS population was approximately 1,800 polar bears, although uneven sampling was known to compromise the accuracy of that estimate. A population analysis of the SBS stock was completed in June 2006 through joint research coordinated between the United States and Canada. That analysis indicated the population within the region between Icy Cape and Pearce Point is now approximately 1,500 polar bears (95 percent confidence intervals approximately 1,000-2,000). Although the confidence intervals of the current population estimate overlap the previous population estimate of 1,800; other statistical and ecological evidence ( e.g. , high recapture rates encountered in the field) suggest that the current population is actually smaller than has been estimated for this area in the past. Recent analyses of radio-telemetry data of spatio-temporal use patterns of bears of the SBS stock using new spatial modelling techniques suggest realignment of the boundaries of the Southern Beaufort Sea area. We now know that nearly all bears in the central coastal region of the Beaufort Sea are from the SBS population, and that proportional representation of SBS bears decreases to both the west and east. For example, only 50 percent of the bears occurring in Barrow, Alaska, and Tuktoyaktuk, Northwest Territories, are SBS bears, with the remainder being from the CS and Northern Beaufort Sea populations, respectively. The recent radio-telemetry data indicate that bears from the SBS population seldom reach Pearce Point, which is currently on the eastern management boundary for the SBS population. Only a small proportion of the SBS polar bear population will be found in the Chukchi Sea region during the ice-covered season. This is based on estimates of probabilities of polar bear distribution from each population. The relative probabilities of sighting a bear were developed using satellite radio-telemetry data. This technique has also increased our understanding of the proportions of the populations that could occur in the region where both populations overlap. These probabilities indicate that SBS polar bears will be found at lower proportions in the western portions of their range (Chukchi Sea) than in the central portions of their range (central Beaufort Sea). Management and conservation concerns for the CS and SBS polar bear populations include: climate change, which continues to increase both the expanse and duration of open water in summer and fall; human activities within the near-shore environment, including hydrocarbon development and production; atmospheric and oceanic transport of contaminants into the Arctic; and the potential for inadvertent over-harvest, should polar bear stocks become nutritionally stressed or decline due to some combination of the above concerns. Today, habitat loss, illegal hunting, and, in particular, the diminishing extent, thickness, and seasonal persistence of sea ice pose the most serious threats to polar bears worldwide. As a result of such concerns, the polar bear was listed as threatened under the U.S. Endangered Species Act of 1973, as amended (ESA), on May 15, 2008 (73 FR 28212). More information can be found at: http://www.fws.gov/ . 2. Habitat Polar bears of the Chukchi Sea are subject to the movements and coverage of the pack-ice and annual ice as they are dependent on the ice as a platform for hunting and surviving. Polar bears are widely distributed within their range and are generally solitary animals, although they will form aggregations around food sources. Historically, polar bears of the Chukchi Sea have spent most of their time on the annual ice in near-shore, shallow waters over the productive continental shelf, which is associated with the shear zone and the active ice adjacent to the shear zone. Sea ice and food availability are two important factors affecting the distribution of polar bears. During the ice-covered season, bears use the extent of the annual ice. The most extensive north-south movements of polar bears are associated with the spring and fall ice movement. For example, during the 2006 ice-covered season, six bears radio-collared in the Beaufort Sea were located in the Chukchi and Bering Seas as far south as 59° latitude, which was the farthest extent of the annual ice during 2006. A small number of bears sometimes remain on the Russian and Alaskan coasts during the initial stages of ice retreat in the spring. Polar bear distribution during the open-water season in the Chukchi Sea, where maximum open water occurs in September, is dependent upon the location of the ice edge as well. The summer ice pack can be quite disjointed and segments can be driven great distances by wind carrying polar bears with them. Recent telemetry movement data are lacking for bears in the Chukchi Sea; however, an increased trend by polar bears to use coastal habitats in the fall during open-water and freeze-up conditions has been noted by researchers since 1992. Recently, during the minimum sea ice extents, which occurred in 2005 and 2007, polar bears exhibited this coastal movement pattern as observations from Russian biologists and satellite telemetry data of bears in the Beaufort Sea indicated that bears were found on the sea ice or along the Chukotka coast during the open-water period. 3. Denning and Reproduction Although insufficient data exist to accurately quantify polar bear denning along the Alaskan Chukchi Sea coast, dens in the area appear to be less concentrated than for other areas in the Arctic. The majority of denning of CS polar bears occurs in Russia on Wrangel Island, Herald Island, and certain locations on the northern Chukotka coast. In addition, due to changes in the formation of sea ice along the Chukotka coast, there are some indications that the Bear Islands (Medvezhiy Ostrova), near the Kolyma River estuary, have become a denning area for the CS stock as well. Females without dependent cubs breed in the spring. Females can initiate breeding at five to six years of age. Females with cubs do not mate. Pregnant females enter maternity dens by late November, and the young are usually born in late December or early January. Only pregnant females den for an extended period during the winter; other polar bears may excavate temporary dens to escape harsh winter winds. An average of two cubs are born. Reproductive potential (intrinsic rate of increase) is low. The average reproductive interval for a polar bear is three to four years, and a female polar bear can produce about 8 to 10 cubs in her lifetime; in healthy populations, 50 to 60 percent of the cubs will survive. Female bears can be quite sensitive to disturbances during this denning period. In late March or early April, the female and cubs emerge from the den. If the mother moves young cubs from the den before they can walk or withstand the cold, mortality to the cubs may increase. Therefore, it is thought that successful denning, birthing, and rearing activities require a relatively undisturbed environment. Radio and satellite telemetry studies elsewhere indicate that denning can occur in multi-year pack-ice and on land. Recent studies of the SBS indicate that the proportion of dens on pack-ice have declined from approximately 60 percent in 1985-1994 to 40 percent in 1998-2004. 4. Prey Ringed seals ( Phoca hispida ) are the primary prey of polar bears in most areas. Bearded seals ( Erignathus barbatus ) and walrus calves are hunted occasionally. Polar bears can opportunistically scavenge marine mammal carcasses. Polar bears will occasionally feed on bowhead whale ( Balaena mysticetus ) carcasses at Point Barrow, Cross, and Barter Islands, areas where bowhead whales are harvested for subsistence purposes. There are also reports of polar bears killing beluga whales ( Delphinapterus leucas ) trapped in the ice. Polar bears are also known to ingest anthropogenic, nonfood items including Styrofoam, plastic, antifreeze, and hydraulic and lubricating fluids. Polar bears use the sea ice as a platform to hunt seals. Polar bears hunt seals using various means. They can hunt along leads and other areas of open water, by waiting at a breathing hole, or by breaking through the roof of a seal lair. Lairs are excavated in snow drifts on top of the ice. Bears also stalk seals in the spring when they haul out on the ice in warm weather. The relationship between ice type and polar bear distribution is as yet unknown, but it is suspected to be related to seal availability. Due to changing sea ice conditions the area of open water and proportion of marginal ice has increased and extends later in the fall. This may limit seal availability to polar bears as the most productive areas for seals appear to be over the shallower waters of the continental shelf. 5. Mortality Polar bears are long-lived (up to 30 years) and have no natural predators, and they do not appear to be prone to death by diseases or parasites. Cannibalism by adult males on cubs and occasionally on other bears is known to occur. The most significant source of mortality is man. Before the MMPA was passed in 1972, polar bears were taken by sport hunters and residents. Between 1925 and 1972, the mean reported kill was 186 bears per year. Seventy-five percent of these were males, as cubs and females with cubs were protected. Since 1972, only Alaska Natives from coastal Alaskan villages have been allowed to hunt polar bears in the United States for their subsistence uses or for handicraft and clothing items for sale. The Native hunt occurs without restrictions on sex, age, or number provided that the population is not determined to be depleted. From 1980 to 2005, the total annual harvest for Alaska averaged 101 bears: 64 percent from the Chukchi Sea and 36 percent from the Beaufort Sea. Other sources of mortality related to human activities include bears killed during research activities, euthanasia of injured bears, and defense of life kills by non-Natives. 6. Distributions and Abundance of Polar Bears in the Chukchi Sea Polar bears are seasonably abundant in the Chukchi Sea and Lease Sale Area 193 and their distribution is influenced by the movement of the seasonal pack-ice. Polar bears in the Chukchi and Bering Seas move south with the advancing ice during fall and winter and move north in advance of the receding ice in late spring and early summer. The distance between the northern and southern extremes of the seasonal pack-ice is approximately 800 miles. In May and June, polar bears are likely to be encountered in the Lease Sale Area 193 as they move northward from the northern Bering Sea through the Bering Strait into the southern Chukchi Sea. During the fall/early winter period, polar bears are likely to be encountered in the Lease Sale Area 193 during their southward migration in late October and November. Furthermore, bears from the SBS and CS populations can be encountered in the Chukchi Sea as they travel with the pack-ice or ice floes in search of food. Polar bears are dependent upon the sea ice for foraging and the most productive areas to be near the ice edge, leads, or polynyas over the continental shelf where the ocean depth is minimal. In addition, polar bears could be present along the shoreline in this area, as they will opportunistically scavenge on marine mammal carcasses washed up along the shoreline and they may become stranded on land due to the receding pack-ice. Subsistence Use and Harvest Patterns of Pacific Walruses and Polar Bears Walruses and polar bears have been traditionally harvested by Alaska Natives for subsistence purposes. The harvest of these species plays an important role in the culture and economy of many coastal communities in Alaska and Chukotka. Walrus meat is consumed by humans and dogs, and the ivory is used to manufacture traditional arts and crafts. Polar bears are primarily hunted for their fur, which is used to manufacture cold weather gear; however, their meat is also occasionally consumed. The communities most likely to be impacted by the proposed activities are Point Hope, Point Lay, Wainwright, and Barrow. An exemption under section 101(b) of the MMPA allows Alaska Natives who reside in Alaska and dwell on the coast of the North Pacific Ocean or the Arctic Ocean to take walruses and polar bears if such taking is for subsistence purposes, including creating and selling authentic native articles of handicrafts and clothing, as long as the take is not done in a wasteful manner. Under the terms of the MMPA, there are no restrictions on the number, season, or ages of walruses or polar bears that can be harvested in Alaska. A more restrictive Inuvialuit-Inupiat Polar Bear Native-to-Native Agreement (Native Agreement) between the Inupiat in Northern Alaska and the Inuvialuit in the Northwest Territories Canada was created for the SBS bears in 1988. Polar bears harvested from the communities of Barrow and Wainwright are currently considered part of the SBS stock and thus are subject to the terms of the Native Agreement. The Native Agreement establishes quotas and recommendations concerning protection of denning females, family groups, and methods of take. Quotas are based on estimates of population size and age-specific estimates of survival and recruitment. The polar bears harvested by the communities of Point Hope and Point Lay are thought to come primarily from the Chukchi/Bering sea stock. Neither Point Hope nor Point Lay hunters are parties to the Native Agreement. The Service collects information on the subsistence harvest of walruses and polar bears in Alaska through the Marking, Tagging and Reporting Program (MTRP). The program is administered through a network of MTRP “taggers” employed in subsistence hunting communities. The marking and tagging Rule requires that hunters report harvested walruses and polar bears to MTRP taggers within 30 days of kill. Taggers also certify (tag) specified parts (ivory tusks for walruses, hide and skull for polar bears) to help control illegal take and trade. MTRP reports are thought to generally underestimate the total U.S. subsistence walrus harvest, with one recent estimate as low as 30 percent of actual harvest in Barrow. According to Service records, polar bear harvests reported by the MTRP are believed to be as high as 80 percent of the actual subsistence harvest in the communities most affected by this regulation. Harvest levels of polar bears and walruses in these communities vary considerably between years, presumably in response to differences in animal distribution and ice conditions. Descriptive information on subsistence harvests of walruses and polar bears in each community is presented below. Point Hope Between 1990 and 2006, the average annual walrus harvest recorded through the MTRP at Point Hope was 3.6 (± 5.1, SD) animals per year. Point Hope hunters typically begin their walrus hunt in late May and June as walruses migrate into the Chukchi Sea. The sea ice is usually well off shore of Point Hope by July and does not bring animals back into the range of hunters until late August and September. Most (70.8 percent) of the reported walrus harvest at Point Hope occurred in the months of June and September. Most of the walruses recorded through the MTRP at Point Hope were taken within five miles of the coast, or near coastal haulout sites at Cape Lisburne. Between 1990 and 2006, the average reported polar bear harvest at Point Hope was 13.1 ± 4.8 animals per year. Polar bear harvests typically occur from January to April. Most of the polar bears reported through the MTRP program were harvested within 10 miles of the community; however, residents also reported taking polar bears as far away as Cape Thompson and Cape Lisburne. Point Lay Point Lay hunters reported an average of 2.2 ± 2.0 walruses per year between 1990 and 2006. Based on MTRP data, walrus hunting in Point Lay peaks in June-July with 84.4 percent of all walruses being harvested during these months. Historically, harvests have occurred primarily within 40 miles north and south along the coast from Point Lay and approximately 30 miles offshore. Between 1990 and 2006, the average reported polar bear harvest at Point Lay was 2.3 ± 1.4 animals per year. The only information on harvest locations comes from the MTRP database; all reported harvest occurred within 25 miles of Point Lay. Wainwright Wainwright hunters have consistently harvested more walruses than any other subsistence community on the North Slope. Between 1990 and 2006, the average reported walrus harvest in Wainwright was 44.2 ± 29.2 animals per year. A discrepancy between MTRP data and past household surveys is noted. Walruses are thought to represent approximately 40 percent of the communities' annual subsistence diet of marine mammals. Wainwright residents hunt walruses from June through August as the ice retreats northward. Walruses can be plentiful in the pack-ice near the village this time of year. Most (85.2 percent) of the harvest occurs in June and July. Most walrus hunting is thought to occur within 20 miles of the community, in all seaward directions. Between 1990 and 2006, the average reported polar bear harvest at Wainwright was 6.8 ± 3.7 animals per year. Polar bears are harvested throughout much of the year, with peak harvests reported in May and December. Polar bear are often harvested coincidentally with beluga and bowhead whale harvests. MTRP data indicate that most hunting occurs within 10 miles of the community. Barrow Barrow is the northernmost community within the geographical region being considered. Most (88.6 percent) walrus hunting occurs in June and July when the land-fast ice breaks up and hunters can access the walruses by boat as they migrate north on the retreating pack-ice. Walrus hunters from Barrow sometimes range up to 60 miles from shore; however, most harvests reported through the MTRP have occurred within 30 miles of the community. Between 1990 and 2006, the average reported walrus harvest in Barrow was 24.1 ± 14.6 animals per year. Between 1990 and 2006, the average reported polar bear harvest at Barrow was 21.3 ± 8.9 animals per year. The number of polar bears harvested in Barrow is thought to be influenced by ice conditions and the number of people out on the ice. Most (74 percent) of all polar bear harvests reported by Barrow residents occurred in February and March. Although relatively few people are thought to hunt specifically for polar bears, those that do hunt primarily between October and March. Hunting areas for polar bears overlap strongly with areas of bowhead subsistence hunting; particularly the area from Point Barrow south to Walakpa Lagoon where walrus and whale carcasses are known to attract polar bears. Potential and Observed Impacts of Oil and Gas Industry Activities on Pacific Walruses and Polar Bears Pacific Walruses A. Potential Impacts of Oil and Gas Industry Activities on Pacific Walruses 1. Disturbance Proposed oil and gas exploration activities in the Chukchi Sea Region include the operation of seismic survey vessels, drill ships, icebreakers, supply boats, fixed-winged aircrafts, and helicopters. Operating this equipment near walruses without appropriate mitigation measures could result in disturbances. Potential effects of disturbances on walruses include insufficient rest, increased stress and energy expenditure, interference with feeding, masking of communication, and impaired thermoregulation of calves that spend an increased amount of time in the water. Prolonged or repeated disturbances could potentially displace individuals or herds from preferred feeding or resting areas. Disturbance events can cause walrus groups to abandon land or ice haul-outs. Severe disturbance events occasionally result in trampling injuries or cow-calf separations, both of which are potentially fatal. Calves and young animals at the perimeter of the herds appear particularly vulnerable to trampling injuries. The response of walruses to disturbance stimuli is highly variable. Anecdotal observations by walrus hunters and researchers suggest that males tend to be more tolerant of disturbances than females and individuals tend to be more tolerant than groups. Females with dependent calves are considered least tolerant of disturbances. Hearing sensitivity is assumed to be within the 13 Hz and 1,200 Hz range of their own vocalizations. Walrus hunters and researchers have noted that walruses tend to react to the presence of humans and machines at greater distances from upwind approaches than from downwind approaches, suggesting that odor is also a stimulus for a flight response. The visual acuity of walruses is thought to be less than for other species of pinnipeds. Walruses are poorly adapted to life in the open ocean. They must periodically haul out onto ice or land to rest between feeding bouts. Previous aerial survey efforts in the offshore region of the eastern Chukchi Sea found that most (80-96 percent) walruses were closely associated with sea ice and that the number of walruses observed in open water decreased significantly with distance from the pack ice. Under minimal or no-ice conditions, we expect most walruses will either migrate out of the region in pursuit of more favorable ice habitats, or relocate to coastal haulouts where their foraging trips will be restricted to near-shore habitats. Therefore, in evaluating the potential impacts of exploration activities on Pacific walruses, the presence or absence of pack ice could serve as one indicator of whether or not walruses are likely to be found in the area. Activities occurring in or near sea ice habitats are presumed to have the greatest potential for interacting with walruses. Activities occurring under open water conditions are expected to interact with relatively small numbers of animals. Seismic operations are expected to add significant levels of noise into the marine environment. Although the hearing sensitivity of walruses is poorly known, source levels associated with Marine 3D and 2D seismic surveys are thought to be high enough to cause temporary hearing loss in other pinniped species. Therefore, walruses within the 180-decibel (dB re 1 μPa) safety radius described by Industry for seismic activities could potentially suffer shifts in hearing thresholds and temporary hearing loss. Seismic survey vessels will be required to ramp up airguns slowly to allow marine mammals the opportunity to move away from potentially injurious sound sources. Marine mammal monitors will also be required to monitor seismic safety zones and call for the power down or shut down of airgun array if any marine mammals are detected within the prescribed safety zone. Geotechnical seismic surveys and high-resolution site clearance seismic surveys are expected to occur primarily in open water conditions, at a sufficient distance from the pack-ice and large concentrations of walruses to avoid most disturbances. Although most walruses are expected to be closely associated with sea ice or coastal haulouts during offshore exploration activities, small numbers of animals may be encountered in open water conditions. Walruses swimming in open water will likely be able to detect seismic airgun pulses up to several kilometers from a seismic source vessel. The most likely response of walruses to noise generated by seismic surveys will be to move away from the source of the disturbance. Because of the transitory nature of the proposed seismic surveys, impacts to walruses exposed to seismic survey operations are expected to be temporary in nature and have little or no effects on survival or recruitment. Although concentrations of walruses in open water environments are expected to be low, groups of foraging or migrating animals transiting through the area may be encountered. Adaptive mitigation measures based upon real time monitoring information will be implemented to mitigate potential impacts to walrus groups feeding in offshore locations and ensure that these impacts are limited to small numbers of animals. The National Marine Fisheries Service (NMFS) identified that Level B harassment of marine mammals begins at 160-dB re 1 μPa. The Service concurs with this determination and believes its use is applicable to walrus aggregations. For that reason, whenever an aggregation of 12 or more walruses are detected within an acoustically verified 160-dB re 1 μPa disturbance zone ahead of or perpendicular to the seismic vessel track, the Service will require the operator to immediately power down the seismic airgun array and/or other acoustic sources to ensure sound pressure levels at the shortest distance to the aggregation do not exceed 160-dB re 1 μPa. The operator will not be allowed to proceed with powering up the seismic airgun array until it can be established that there are no walrus aggregations within the 160-dB zone based upon ship course, direction, and distance from last sighting. Offshore exploration activities are expected to occur primarily in areas of open water some distance from the pack-ice; however, support vessels and/or aircraft may occasionally encounter aggregations of walruses hauled out onto sea ice. The sight, sound, or smell of humans and machines could potentially displace these animals from ice haul-outs. Ice management operations are expected to have the greatest potential for disturbances since these operations typically require vessels to accelerate, reverse direction, and turn rapidly, activities that maximize propeller cavitations and resulting noise levels. Previous studies suggest that icebreaking activities can displace some walrus groups up to several miles away; however, most groups of hauled out walruses showed little reaction beyond 805 m (0.5 mi). Impacts associated with transiting support vessels and aircrafts are likely to be distributed in time and space. Therefore, noise and disturbance from aircraft and vessel traffic associated with exploration projects are expected to have relatively localized, short-term effects. Nevertheless, the potential for disturbance events resulting in injuries, mortalities, or mother-calf separations is of concern. The potential for injuries is expected to increase with the size of affected walrus aggregations. Adaptive mitigation measures designed to separate Industry activities from walrus aggregations at coastal haulouts and in sea-ice habitats are expected to reduce the potential for animal injuries, mortalities, and mother-calf separations. Restricting offshore exploration activities to the open-water season (July 1 to November 30) is also expected to reduce the number of potential interactions between walruses and Industry operations occurring in or near sea ice habitats. Adaptive operational restrictions, including an 800-m (0.5-mi) operational exclusion zone for marine vessels, and a 305-m (1,000-ft) altitude restriction for aircraft flying near walrus groups hauled-out onto land or sea ice, are similarly expected to minimize disturbances to walruses hauled out onto ice or land. Drilling operations are expected to occur at several offshore locations during the later stages of the regulations. Although drilling activities are expected to occur primarily during open water conditions, the dynamic movements of sea ice could transport walruses within range of drilling operations. The MMS permit stipulation identifying a 0.5-mile operational exclusion zone around groups of hauled-out walruses is expected to help mitigate disturbances to walruses near prospective drill sites. Mitigation measures specified in an LOA including requirements for ice-scouting, surveys for walruses and polar bears in the vicinity of active drilling operations and ice breaking activities, requirements for marine mammal observers onboard drill ships and ice breakers, and operational restrictions near walrus and polar bear aggregations are expected to further reduce the potential for interactions between walruses and drilling operations. 2. Waste Discharge and Oil Spills The potential exists for fuel and oil spills to occur from seismic and support vessels, fuel barges, and drilling operations. Little is known about the effects of fuel and oil on walruses; however, walruses may react to fuel and oil much like other pinniped species. Damage to the skin of pinnipeds can occur from contact with oil because some of the oil penetrates into the skin, causing inflammation and ulcers. Exposure to oil can quickly cause permanent eye damage. In studies conducted on other pinniped species, pulmonary hemorrhage, inflammation, congestion, and nerve damage resulted after exposure to concentrated hydrocarbon fumes for a period of 24 hours. Walruses are extremely gregarious animals and normally associate in large groups; therefore, any contact with spilled oil or fuel could impact several individuals. Exposure to oil could also impact benthic prey species. Bivalve mollusks, a favorite prey species of the walrus, are not effective at processing hydrocarbon compounds, resulting in highly concentrated accumulations and long-term retention of contamination within the organism. Exposure to oil may kill prey organisms or result in slower growth and productivity. Because walrus feed primarily on mollusks, they may be more vulnerable to a loss of this prey species than other pinnipeds that feed on a larger variety of prey. Although fuel and oil spills have the potential to cause adverse impacts to walruses and prey species, operational spills associated with the proposed exploration activities are not considered a major threat. Operational spills would likely be of a relatively small volume, and occur in areas of open water where walrus densities are expected to be relatively low. Furthermore, blowout prevention technology will be required for all exploratory drilling operations in the Chukchi Sea by the permitting agencies, and the MMS considers the likelihood of a blowout occurring during exploratory drilling in the Chukchi Sea as negligible (OCS EIS/EA MMS 2007-026). The MMS operating stipulations, including oil spill prevention and response plans, reduce both the risk and scale of potential spills. For these reasons, any impacts associated with an operational spill are expected to be limited to a small number of animals. Despite the minimal risk, all projects will have oil spill contingency plans (specific to the project) that will be approved by the appropriate permitting agencies prior to the issuance of an LOA. The contingency plans have a wildlife component, which outlines protocols to minimize wildlife exposure, including polar bears and walruses, to oil spills. 3. Cumulative Effects The following events have contributed to current environmental conditions in the Chukchi Sea and could also cumulatively affect Pacific walrus population status in the next five years: Commercial and Subsistence Harvest —Walruses have an intrinsically low rate of reproduction and are thus limited in their capacity to respond to exploitation. In the late 19th century, American whalers intensively harvested walruses in the northern Bering and southern Chukchi seas. Between 1869 and 1879, catches averaged more than 10,000 per year, with many more animals struck and lost. The population was substantially depleted by the end of the century, and the commercial hunting industry collapsed in the early 1900s. Since 1930, the combined walrus harvests of the United States and Russia have ranged from 2,300-9,500 animals per year. Notable harvest peaks occurred during 1930-1960 (4,500-9,500 per year) and in the 1980's (5,000-9,000 per year). Commercial hunting continued in Russia until 1991 under a quota system of up to 3,000 animals per year. Since 1992, the harvest of Pacific walruses has been limited to the subsistence catch of coastal communities in Alaska and Chukotka. Harvest levels through the 1990s ranged from approximately 2,400-4,700 animals per year. Although recent harvest levels are lower than historic highs, lack of information on current population size or trend precludes an assessment of sustainable harvest rates. Climate Change —Analysis of long-term environmental data sets indicates that substantial reductions in both the extent and thickness of the arctic sea-ice cover have occurred over the past 40 years. Record minimum sea ice extent was recorded in 2002, 2005, and again in 2007; sea ice cover in 2003 and 2004 was also substantially below the 20-year mean. Walruses rely on suitable sea ice as a substrate for resting between foraging bouts, calving, molting, isolation from predators, and protection from storm events. The juxtaposition of sea ice over shallow-shelf habitat suitable for benthic feeding is important to walruses. Recent trends in the Chukchi Sea have resulted in seasonal sea-ice retreat off the continental shelf and over deep Arctic Ocean waters, presenting significant adaptive challenges to walruses in the region. Reasonably foreseeable impacts to walruses as a result of diminishing sea ice cover include: shifts in range and abundance; increased vulnerability to predation and disturbance; declines in prey species; increased mortality rates resulting from storm events; and premature separation of females and dependent calves. Secondary effects on animal health and condition resulting from reductions in suitable foraging habitat may also influence survivorship and productivity. Future studies investigating walrus distributions, population status and trends, and habitat use patterns in the Chukchi Sea are important for responding to walrus conservation and management issues associated with environmental and habitat changes. Commercial Fishing and Marine Vessel Traffic —Available data suggest that walruses rarely interact with commercial fishing and marine vessel traffic. Walruses are normally closely associated with sea ice, which limits their interactions with fishing vessels and barge traffic. However, as previously noted, the temporal and seasonal extent of the sea ice is projected to diminish in the future. Commercial shipping through the Northwest Passage and Siberian arctic waters may develop in coming decades. Commercial fishing opportunities may also expand should the sea ice continue to diminish. The result could be increased temporal and spatial overlap between fishing and shipping operations and walrus habitat use and increased interactions between walruses and marine vessels. Past Offshore Oil and Gas Related Activities —Oil and gas related activities have been conducted in the Chukchi and Beaufort Seas since the late 1960's. Much more oil and gas related activity has occurred in the Beaufort Sea than in the Chukchi Sea OCS. Pacific walruses do not normally range into the Beaufort Sea, and documented interactions between oil and gas activities and walruses have been minimal (see Observed Impacts of Oil and Gas Industry Activities on Pacific Walruses). The Chukchi Sea OCS has previously experienced some oil and gas exploration activity, but no development or production. Because of the transitory nature of past oil and gas activities in any given region, we do not think that any of these encounters had lasting effects on individuals or groups. Summary of Cumulative Effects —Hunting pressure, declining sea ice due to climate change, and the expansion of commercial activities into walrus habitat all have potential to impact walruses. Combined, these factors are expected to present significant challenges to future walrus conservation and management efforts. The success of future management efforts will rely in part on continued investments in research investigating population status and trends and habitat use patterns. The effectiveness of various mitigation measures and management actions will also need to be continually evaluated through monitoring programs and adjusted as necessary. The decline in sea ice is of particular concern, and will be considered in the evaluation of future proposed activities and as more information on walrus population status becomes available. Contribution of Proposed Activities to Cumulative Impacts —The proposed seismic surveys and exploratory drilling operations identified by the petitioners are likely to result in some incremental cumulative effects to walruses through the potential exclusion or avoidance of walruses from feeding or resting areas and disruption of associated biological behaviors. However, based on the habitat use patterns of walruses in the Chukchi Sea and their close association with seasonal pack ice, relatively small numbers of walruses are likely to be encountered in the open sea conditions where most of the proposed activities are expected to occur. Required monitoring and mitigation measures, designed to minimize interactions between authorized projects and concentrations of resting or feeding walruses, are also expected to limit the severity of any behavioral responses. Therefore, we conclude that the proposed exploration activities, especially as mitigated through the regulatory process, are not at this time expected to add significantly to the cumulative impacts on the Pacific walrus population from past, present, and future activities that are reasonably likely to occur within the 5-year period covered by the regulations if adopted. B. Observed Impacts of Oil and Gas Industry Activities on Pacific Walruses Oil and gas related activities have been conducted in the Beaufort and Chukchi Seas since the late 1960s. Much more oil and gas related activity has occurred in the Beaufort Sea OCS than in the Chukchi Sea OCS. Many offshore activities required ice management (icebreaking), helicopter traffic, fixed-wing aircraft monitoring, other support vessels, and stand-by barges. Although Industry has encountered Pacific walruses while conducting exploratory activities in the Beaufort and Chukchi seas, to date, no walruses are known to have been killed due to encounters associated with Industry activities. Pacific walruses do not normally range into the Beaufort Sea, although individuals and small groups have been observed. From 1994 to 2004, Industry monitoring programs recorded a total of nine walrus sightings involving a total of 10 animals. Three of the reported sightings involved potential disturbances to walruses; two sightings were of individual animals hauled-out onto the armor of Northstar Island, and one sighting occurred at the McCovey prospect, where a walrus appeared to react to helicopter noise. Physical effects or impacts to individual walruses were not noted. Because of the small numbers of walruses encountered by past and present oil and gas activity in the Beaufort Sea, impacts to the Pacific walrus population appear to have been minimal. Three pre-lease seismic surveys were carried out in the Chukchi Sea OCS planning area in 2006, where marine mammal monitoring was based on vessel and aerial platforms. Marine mammal observers onboard the seismic and support vessels recorded a total of 1,186 walrus sightings during their operations. Most of the walrus sightings were reported by seismic support vessels during ice-scouting missions. Three hundred and eighteen of the walruses sighted (27 percent) exhibited some form of behavioral response to the vessels, primarily dispersal or diving. Seismic vessels, operating in open water conditions, recorded a total of 33 walrus sightings. Marine mammal observers reported 19 incidents in which walruses were observed within a predetermined safety zone of ensonification, requiring the shut down of airgun arrays to prevent potential injuries. Based upon the transitory nature of the survey vessels, and the monitoring reports that noted behavioral reactions of the animals to the passage of the vessels, our best assessment is that these interactions resulted in no more than temporary changes in animal behavior. Additionally, the 2006 Chukchi Sea aerial surveys recorded a total of 1,882 walrus sightings. These regional aerial surveys were conducted in support of seismic activities as part of the marine mammal mitigation. During the three pre-lease seismic surveys conducted using vessel and aircraft platforms, a total of 3,068 walrus were observed. This represents a relatively small portion of the total number of animals that occurred at low densities within the open-water study area. Aerial surveys and vessel-based observations of walruses were carried out in 1989 and 1990 to examine the responses of walruses to drilling operations at three Chukchi Sea drill prospects. Aerial surveys documented several thousand walruses in the vicinity of the drilling prospects; most of the animals (> 90 percent) were closely associated with sea ice. The monitoring reports concluded that: (1) Walrus distributions were closely linked with pack ice; (2) pack ice was near active drill prospects for relatively short time periods; and (3) ice passing near active prospects contained relatively few animals, concluded that effects of the drilling operations on walruses were limited in time, geographical scale, and proportion of the affected population. C. Evaluation Based on our review of the proposed activities; existing and proposed operating conditions and mitigation measures; information on the biology, ecology, and habitat use patterns of walruses in the Chukchi Sea; information on potential effects of oil and gas activities on walruses; and the results of previous monitoring efforts associated with Industry activity in the Beaufort and Chukchi Seas, we conclude that, while the incidental take (by harassment) of walruses is reasonably likely to or reasonably expected to occur as a result of the proposed activities, most of the anticipated takes will be limited to temporary, nonlethal disturbances impacting a relatively small numbers of animals. Our review of the nature and scope of the proposed activities, when considered in light of the observed impacts of past exploration activities by Industry, indicates that it is unlikely that there will be any lethal take of walruses associated with these activities or any impacts on survivorship or reproduction. Polar Bears A. Potential Impacts of Oil and Gas Industry Activities on Polar Bears 1. Disturbance In the Chukchi Sea, polar bears will have a limited presence during the open-water season during Industry operations. It is assumed they generally move to the northwestern portion of the Chukchi Sea and distribute along the pack-ice during this time, which is outside of the geographic region of the regulations. Additionally, they are found more frequently along the Chukotka coastline in Russia. This limits the chances of impacts on polar bears from Industry activities. Although polar bears have been observed in open-water, miles from the ice edge or ice floes, this has been a relatively rare occurrence. Offshore Activities. In the open-water season, Industry activities will be limited to vessel-based exploration activities, such as seismic surveys and site clearance surveys and during the latter part of the regulatory period, offshore exploratory drilling may occur. These activities avoid ice floes and the multi-year ice edge; however, they could contact a limited number of bears in open water. Seismic exploration activities in the Chukchi Sea could affect polar bears in a number of ways. Seismic ships and icebreakers may be physical obstructions to polar bear movements, although these impacts are of short-term and localized effect. Noise, sights, and smells produced by exploration activities could repel or attract bears, either disrupting their natural behavior or endangering them by threatening the safety of seismic personnel. Little research has been conducted on the effects of noise on polar bears. Currently, researchers are studying the hearing sensitivity of polar bears to understand how noise affects polar bears. Polar bears are curious and tend to investigate novel sights, smells, and possibly noises. Noise produced by seismic activities could elicit several different responses in individual polar bears. Noise may act as a deterrent to bears entering the area of operation, or the noise could potentially attract curious bears. In general, little is known about the potential for seismic survey sounds to cause auditory impairment or other physical effects in polar bears. Available data suggest that such effects, if they occur at all, would be limited to short distances and probably to projects involving large airgun arrays. There is no evidence that airgun pulses can cause serious injury, or death, even in the case of large airgun arrays. Additionally, the planned monitoring and mitigation measures include shut downs of the airguns, which will reduce any such effects that might otherwise occur if polar bears are observed in the ensonification zones. Polar bears normally swim with their heads above the surface, where underwater noises are weak or undetectable, and this behavior may naturally limit noise exposure to polar bears. Thus, it is doubtful that any single bear would be exposed to strong underwater seismic sounds long enough for significant disturbance, such as an auditory injury, to occur. Polar bears are known to run from sources of noise and the sight of vessels, icebreakers, aircraft, and helicopters. The effects of fleeing from aircraft may be minimal if the event is short and the animal is otherwise unstressed. On a warm spring or summer day, a short run may be enough to overheat a well-insulated polar bear; however, fleeing from a working icebreaker may have minimal effects for a healthy animal on a cool day. As already stated, polar bears spend the majority of their time on pack-ice during the open-water season in the Chukchi Sea or along the Chukotka coast, which limits the chance of impacts from human and Industry activities in the geographic region. In recent years, the Chukchi Sea pack-ice has receded over the Continental Shelf during the open water season. Although this poses potential foraging ramifications, by its nature the exposed open water creates a barrier between the majority of the ice pack-bound bear population and human activity occurring in open water, thereby limiting potential disturbance. Researchers have observed that bears occasionally swim long distances during the open-water period seeking either ice or land. In 2005, researchers monitored one radio-collared individual as it swam through ice-free waters from Kotzebue north to the pack-ice 350 miles away. The bear began swimming on June 16, 2005, rested twice in open water (presumably on icebergs) and eventually reached the pack-ice on July 2, 2005. Researchers suspected that the bear was not swimming constantly, but found solitary icebergs or remnants to haul-out on and rest. The movement is unusual, but highlights the ice-free environment that bears are being increasingly exposed to that requires increased energy demands. Seismic activities avoid ice floes and the pack-ice edge; however, they may contact bears in open water. It is unlikely that seismic exploration activities would result in more than temporary behavioral disturbance to polar bears. Vessel traffic could result in short-term behavioral disturbance to polar bears. If a ship is surrounded by ice, it is more likely that curious bears will approach. Any on-ice activities required by exploration activities create the opportunity for bear-human interactions. In relatively ice-free waters, polar bears are less likely to approach ships, although they could be encountered on ice floes. For example, during the late 1980s, at the Belcher exploration drilling site in the Beaufort Sea, in a period of little ice, a large floe threatened the drill rig at the site. After the floe was moved by an ice breaker, workers noticed a female bear with a cub-of-the-year and a lone adult swimming nearby. It was assumed these bears had been disturbed from the ice floe. Ships and ice breakers may act as physical obstructions, altering or intercepting bear movements in the spring during the start-up period for exploration if they transit through a restricted lead system, such as the Chukchi Polynya. Polynyas are important habitat for ice seals and walrus, which makes them important hunting areas for polar bears. A similar situation could occur in the fall when the pack-ice begins to expand. The separation of polar bears, whether on land, on ice, or in water, and marine vessels by creating an operational exclusion zone would limit potential impact of marine vessels to polar bears. High altitude routine aircraft traffic appears to have little to no effect on polar bears; however, extensive or repeated over-flights of fixed-wing aircraft or helicopters could disturb polar bears. Behavioral reactions of polar bears are expected to be limited to short-term changes in behavior that would have no long-term impact on individuals and no identifiable impacts on the polar bear population. In the later years of the regulations, offshore exploratory drilling may occur during the open water seasons. Disturbances to polar bears by vessel and aircraft traffic used in support of exploratory drilling would be similar to those that have already been described. Monitoring and mitigation measures required for open water, offshore activities will include, but will not be limited to: (1) A 0.5-mile operational exclusion zone around polar bear(s) on land, ice, or swimming; (2) MMOs on board all vessels; (3) requirements for ice-scouting; (4) surveys for polar bears in the vicinity of active operations and ice breaking activities; and (5) operational restrictions near polar bear aggregations. These mitigation measures are expected to further reduce the potential for interactions between polar bears and offshore operations. Onshore Activities. Onshore activities will have the potential to interact with polar bears mainly during the fall and ice-covered season when bears come ashore to feed, den, or travel. Noise produced by Industry activities during the open-water and ice-covered seasons could potentially result in takes of polar bears at onshore activities. During the ice-covered season, denning female bears, as well as mobile, non-denning bears, could be exposed to oil and gas activities, such as seismic exploration or exploratory drilling facilities, and could potentially be affected in different ways. Noise disturbance can originate from either stationary or mobile sources. Stationary sources include exploratory drilling operations and their associated facilities. Mobile sources can include vehicle and aircraft traffic in association with Industry activities, such as ice road construction and vibroseis programs. Noise produced by stationary Industry activities could elicit several different responses in polar bears. The noise may act as a deterrent to bears entering the area, or the noise could potentially attract bears. Attracting bears to these facilities, especially exploration facilities in the coastal or nearshore environment, could result in human-bear encounters, which could result in unintentional harassment, lethal take, or intentional hazing (under separate authorization) of the bear. During the ice-covered season, noise and vibration from exploratory drilling facilities could deter females from denning in the surrounding area, although polar bears have been known to den in proximity to industrial activities without any perceived impacts. For example, in 1991, two maternity dens were located on the south shore of a barrier island within 2.8 km (1.7 mi) of an already established production facility. In addition, during the ice-covered season of 2001-2002, two known polar bear dens were located within approximately 0.4 km and 0.8 km (0.25 mi and 0.5 mi) of remediation activities on Flaxman Island that were initiated after denning presumably occurred. Through increased monitoring efforts, there were no observed impacts to denning success or the polar bears. In contrast, information exists indicating that polar bears may have abandoned dens in the past due to exposure to human disturbance. For example, in January 1985, a female polar bear may have abandoned her den due to rolligon traffic, which occurred between 250 and 500 meters from the den site. Researcher disturbance created by camp proximity and associated noise, which occurred during a den emergence study in 2002 on the North Slope, may have caused a female bear and her cub(s) to abandon their den and move to the ice sooner than necessary. The female was observed later without the cub(s). While such events caused by Industry-related activities may have occurred in the Beaufort Sea, information indicates they have been infrequent and isolated. In addition, polar bears exposed to routine industrial noises may acclimate to those noises and show less vigilance than bears not exposed to such stimuli. This implication came from a study that occurred in conjunction with industrial activities performed on Flaxman Island in 2002 and a study of undisturbed dens in 2002 and 2003 (N = 8). Researchers assessed vigilant behavior with two potential measures of disturbance: (1) Proportion of time scanning their surroundings and (2) frequency of observable vigilant behaviors. Bears exposed to industrial activity spent less time scanning their surroundings than bear [Text truncated at 120,000 characters. The full text is on the page linked above.] --- Source: Frix Law Library, https://www.frixlaw.com/law-library/documents/fr%3AE8-12918. Public record. Not legal advice.