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Activities that may affect terrestrial mammals include aerial surveys (including those for wildlife) and ground activities such as resource inventories, paleontological excavations, research camps, recreational camps (hunting and river floating), and overland moves. Overland moves occur during the winter on frozen tundra, ice roads, or stable shorefast ice. The other activities occur from summer to early fall (June-September). Short-term displacement and/or disturbance (few minutes to a few hours) of terrestrial wildlife may result from helicopter and fixed-wing traffic, and ground traffic associated with these activities. Caribou have been shown to exhibit panic or violent flight reactions to aircraft flying at elevations of 162 ft (60 m) and to exhibit strong escape responses (animals trotting or running from aircraft) to aircraft flying at 150 to 1,000 ft (45 to 300 m) (Calef, DeBock, and Lortie, 1976). These documented reactions were from aircraft that circled and repeatedly flew over caribou groups. While aircraft associated with aerial wildlife surveys may circle or fly over a group of caribou more than once, aircraft associated with support of survey/inventory camps would pass over caribou only once on any given flight to or from a camp. Recreational and research camps may result in short-term displacement (24 hours to 6 weeks) or harassment of terrestrial mammals and minor disturbance to the vegetation and soil due to trampling (< 3/4 acre). Potential habitat disturbance from large camps would be reduced by using existing sites whenever possible. Camps may attract bears and foxes, and result in the shooting of bears that learn to associate humans with food sources. Such losses by themselves are expected to be minor or insignificant to the bear population but would contribute to cumulative adverse effects. Direct mortality and degradation of habitat of small rodents (such as lemmings and voles) may occur locally at excavations, camps, and on trails used for overland moves. However, these losses would be insignificant to regional populations on the Arctic Coastal Plain. Current management practices and stipulations developed through the permitting process and attached to land use authorizations for temporary facilities, overland moves, and recreation permits would effectively mitigate impacts to terrestrial mammals. For example, overland moves require the use of low ground pressure vehicles and are permitted to travel only over snow-covered, frozen ground to minimize impacts to vegetation and soil. Special recreation permits stipulate the proper handling of wastes and fuels.
Very small fuel spills (<1 bbl) could occur in association with resource inventory surveys, recreational activities, and overland moves. These spills are likely to involve aviation fuel and other light-fraction hydrocarbon fuels that would evaporate and disperse rapidly in the environment with only a local effect on vegetation. Such events are not expected to have any significant effects on terrestrial mammals.
Under this option, no seismic operations would be conducted within the Planning Area and consequently, there would be no impacts to terrestrial mammals.
One 2-D or 3-D seismic operation (40 to 80 people) would occur in alternate years. Habitat impacts would be minor as seismic activities occur during the winter on frozen tundra, or ice. Potential causes of disturbance to terrestrial mammals from seismic activities include surface vehicular traffic on frozen tundra or ice, and fixed-wing aircraft traffic. In most cases, these activities are expected to cause short-term (few minutes to <1 hour) displacements and/or disturbance of terrestrial mammals. When 3-D seismic exploration survey lines are located only 500 to 2,000 ft apart, localized displacement of terrestrial mammals could last for several days. Effects on caribou and moose would be similar in type to those discussed under non-oil and gas activities, but greater in extent, frequency, and duration.
Studies of the effects of oil and gas exploration on muskoxen in Alaska and Canada have focused on disturbances associated with winter seismic operations. Some muskoxen reacted to seismic activities at distances up to 2.48 mi (4 km) from the operations; however, reactions were highly variable among individuals (Reynolds and LaPlant, 1985). Responses varied from no response to becoming alert, forming defense formations, or running away (Winters and Shideler, 1990). The movements of muskoxen away from the seismic operations did not exceed 3.1 mi (5 km) and had no apparent effect on muskoxen distribution (Reynolds and LaPlant, 1986). Unlike caribou, muskoxen are not able to easily travel and dig through snow. In the winter, they search out sites with shallow snow, and greatly reduce movements and activity to conserve energy (USDOI, FWS, 1999). Muskoxen survive the winter by using stored body fat and reducing movement to compensate for low forage intake (Dau, 2001). Because of this strategy, muskoxen may be more susceptible to disturbances during the winter. Repeated disturbances of the same animals during winter could result in increased energetic costs that may affect mortality rates. Depending upon the location of the seismic exploration, impacts on muskoxen would be non-existent to minimal. Most of the Planning Area is currently unoccupied by muskoxen although, potential habitat encompasses much of the Planning Area and populations outside of the Planning Area are gradually expanding their range. At most, seismic operations would be expected to encounter no more than an occasional lone bull. No breeding groups would be affected except possibly from seismic crews accessing the Planning Area from overland routes from Kuparuk River area.
Exploration activities and human presence pose potentially serious disturbances to denning bears. In one study, seismic activities within 1.15 mi (1.8 km) of a grizzly bear den caused changes in heart rate and movement of the female bear and cubs (Reynolds et. al., 1986). The investigators suggest that seismic testing activities within about 600 ft of a den may cause abandonment of the den. Under this alternative, Stipulation J-2 prohibits exploration activities within ½ mile of occupied grizzly bear dens. If den locations are known in the areas that seismic work occurs, impacts to hibernating bears would be reduced. If den locations were unknown, the stipulation would have little effect. Impacts to bears are expected to be minimal since the level of proposed seismic work is low. In addition, the area of highest potential for oil is the lowest density bear habitat.
Seismic camps may result in localized disturbance and/or displacement of terrestrial mammals for up to a few days. Bears and foxes may also be attracted to camps. However, no adverse impacts are anticipated. Since seismic camps generally move at least once a week and proper handling of wastes is emphasized in the alternative (ROP A-1), the potential for bears or foxes to be attracted to human food sources is low. In addition, most seismic activity would occur when bears are hibernating.
Potential effects on wolverines could include disturbance from air and surface-vehicle traffic, and increased human presence. Wolverines are considered a shy and secretive species, and they may be sensitive to disturbance. Winter seismic activities in the Pik Dunes area south of Teshekpuk Lake are known to have caused the displacement of a wolverine from its den (Harry Brower, Jr., as cited in USDOI, BLM, 1997a).
Small rodents (such as lemmings and voles) may be locally affected through direct mortality and minor loss of habitat from overland traffic associated with seismic operations. Their predators (such as short-tailed weasels) may be indirectly affected in local areas due to a reduction in prey. These losses are expected to be insignificant at the population level.
Among the terrestrial mammal populations that could be affected by management actions under the No Action Alternative are caribou of the Teshekpuk Lake Herd (TLH) and the Western Arctic Herd (WAH). Caribou may be temporarily exposed to helicopter traffic and other human activities associated with resource inventories and seismic operations, but such exposure is not expected to have any effects at the population level. Moose, muskoxen, grizzly bears, wolves, wolverines, foxes, and small mammals may be locally affected by activities in the Planning Area.
Stipulations A-1 and A-2, and ROP A-1 through ROP A-7 - regarding solid- and liquid-waste disposal, fuel handling, and spills - would reduce the potential effects of spills and human refuse on grizzly bears, arctic foxes, and other terrestrial mammals. Stipulation D-2 would minimize alteration of terrestrial mammal habitat by prohibiting construction of permanent facilities during exploration. Stipulations F-1 and F-2 - on aircraft overflights - would minimize disturbance of caribou by requiring minimum altitudes of 1,000 to 2,000 ft above ground level (AGL) over caribou winter ranges and the summer insect-relief area, respectively, during critical times of the year. Stipulation J-2 would prohibit exploration activities within ½ mile of occupied grizzly bear dens. If den locations were known, this would reduce the potential for impacts from seismic operations on hibernating bears.
Under the No Action Alternative, the Northwest NPR-A Planning Area would not be open to oil and gas exploration or development leasing. Seven species of non-endangered marine mammals - ringed, spotted, and bearded seals; walruses; polar bears; and beluga and gray whales - commonly occur year-round or seasonally in coastal habitats adjacent to the Planning Area. Under the No Action Alternative, some individual members of these species may be exposed to effects from activities other than exploration or development.
Ground-impacting management actions along the coast within the Planning Area that may affect non-endangered marine mammals under the No Action Alternative include aerial surveys (including 14 days of surveys of wildlife); ground activities (such as resource inventories), paleontological excavations (about 1 acre disturbed), research (3 weeks for small camps and 6 weeks for large camps) and recreational camps (hunting and river floating), seismic exploration, and overland moves. Overland moves and seismic operations occur during the winter on stable sea ice or frozen tundra. The other activities take place in summer and early fall (June-September). The primary potential causes of disturbance of marine mammals are helicopter and fixed-wing aircraft traffic and humans on foot. These activities, if they occur along the coast of the Planning Area, may cause short-term (<1 hour) displacements or harassment of hauled-out seals and polar bears.
Recreational camps in some cases may attract bears, and this could result in the shooting of bears that learn to associate humans with food sources. Such losses by themselves are expected to be minor or insignificant to the bear population, but would contribute to cumulative adverse effects.
Very small fuel spills (<1 bbl) are expected to occur in association with resource inventories and surveys, recreational activities, and overland moves. These spills are likely to involve aviation fuel and other light-fraction hydrocarbon fuels that would evaporate and disperse rapidly with only local effect on vegetation. Under current regulations, fuel spills are required to be cleaned up immediately, if possible. Such events are not expected to have any significant effects on marine mammals in the Planning Area.
No effects from oil and gas activities on marine mammals are expected to occur under this option.
Handling of food and garbage under stipulations A-1 and A-2 (waste prevention, handling, and disposal) would prevent the attraction of polar bears to campsites, which could result in the taking of polar bears in human/bear interactions. Under stipulation C-1 (overland moves), operators planning winter activities within 25 mi of the coast must consult with FWS to prevent disturbance of denning polar bears. Activities would be prohibited within 1 mi of known polar bear dens. This consultation is expected to prevent most disturbances of denning polar bears under the No Action Alternative. ROP F-1 (aircraft traffic) would reduce the number of disturbances of marine mammals and other wildlife. Under the Marine Mammal Protection Act (MMPA), harassment or "taking" of marine mammals is prohibited unless the lessees have a Letter of Authorization (LOA) that would allow them to unintentionally harass marine mammals during their operations. To limit and avoid excessive harassment or taking of non-endangered marine mammals, the MMPA requires lessees to have an LOA to conduct activities that may harass or take marine mammals. This requirement is expected to limit any disturbance of marine mammals associated with seismic activities in the Northwest NPR-A Planning Area
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