Helicopter flights and vessel traffic should not disturb a major portion of the seal populations or result in substantial effects on their distribution or migration. Although oil spills could result in some mortality among newborn or severely stressed adult ice seals, such incidents should not cause losses exceeding a few hundred individuals which could be replaced within a generation.

Adult walruses should experience few fatalities from oil spills unless they are already severely stressed. Calves however, could experience fatal effects from contact or ingestion of oil. Population effects resulting from oil spills are not likely to require more than one generation for recovery.

The most serious consequence of noise disturbance to polar bears is the displacement of pregnant females from preferred denning areas. If a large oil spill were to occur, it could cause mortality in polar bears of up to 50 individuals throughout the entire Alaska Region, affecting only a few individuals in any given local population and requiring no more than one generation for the local population to recover. Where bears are concentrated near abundant prey, these effects could result in losses requiring a generation or more for the population to return to its initial status.

In the Gulf of Mexico, operations could affect whales and dolphins by the degradation of water quality resulting from operational discharges, noise from helicopter and vessel traffic, noise from working platforms and drillships, explosive platform removals, seismic surveys, oil spills, oil-spill response activities, and discarded debris from service vessels and OCS structures. The majority of these impacts should be sublethal. Lethal effects would most likely result from vessel collisions, ingestion of plastics, and oil spills.

In Alaska the effects on caribou could include local displacement of cow/calf groups within about 1 to 2 km along pipelines and roads, persisting for more than one generation. Brief disturbances could occur along road and pipeline corridors during periods of high traffic, but should not affect migrations, overall distribution, and abundance. Oil spills should have little impact on caribou.

In the Gulf of Mexico, no significant adverse effects to Alabama, Choctawhatchee, and Perdido Key beach mice are predicted.

The effect of air traffic in the Alaska Region is expected to be limited to disturbance of coastal and shorebird populations within 0.5 km of the flight path, with some local reductions in productivity, and recovery occurring within 1 year. Construction activities could cause a reduction in shorebird productivity near construction sites. Abandonment of up to 10 percent of threatened arctic and endangered American peregrine falcon nests located within 3 km of onshore activities could occur. This could result inreduced reproduction in those areas. Overall routine effects, entanglement in debris, and ingestion of plastics in relation to the Steller's, and spectacled eider, and on the short-tailed albatross should be minimal, affecting less than 4 percent of the population; however, mortality resulting from an oil spill could require two generations or more for recovery.

Air traffic and coastal construction activities could disturb a small number of pairs of nesting eagles and require the equivalent of one generation for recovery of any loss in local productivity. If multiple tanker spills occur in the Gulf of Alaska, where the bald eagle population is concentrated, mortality involving a loss of 50 to 150 individuals is possible, requiring a minimum of three generations for recovery.

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Disturbance from routine operations is not expected to cause measurable impacts to diving ducks. Oil spills could result in losses to populations occupying nearshore and lagoon habitats of several thousand requiring as many as two generations for recovery. Those occupying open-water habitats farther offshore in the Beaufort and Chukchi Seas in spring, and through much of the Gulf of Alaska, could sustain losses of up to 10,000 individuals, requiring several generations for recovery if a large oil spill contacted these areas.

Routine offshore activities could affect a few hundred individuals or less out of geese populations requiring no more than one generation for recovery. The impact of oil spills on most goose species could result in losses up to a few hundred, requiring no more than one generation for recovery; impacts on the tule and dusky Canada goose could take more than one generation to recover.

There could be disturbance and mortality of seabirds, requiring less than one generation for recovery. The major impact-producing factor is likely to be spilled oil which could cause losses of up to 5 percent of local breeding seabird populations. Specific populations of black storm-petrel, Xantus' murrelet, marbled murrelet, red-legged kittiwake, and whiskered auklet could require at least three generations to recover if contacted by a large oil spill. During the non-breeding period, any losses from contact with oil should require no more than one generation for recovery except in the eastern Aleutian Chain area, where several generations could be required.

A spill could occur along the West Coast from a tanker carrying imported oil, or oil from the Alaska OCS or North Slope. If the spill contacted the Washington/Oregon coast and nonresident wintering seabird colonies, the result could bethe loss of hundreds to several thousand seabirds, with a recovery period of one generation or more. Wintering populations of the white winged and surf scooters are the most abundant waterfoul species off California. An oil spill contacting these species should not cause losses requiring more than one generation for recovery because of their high reproductive potential.

In the Gulf of Mexico there will be no discernible decline in marine or coastal bird populations or species, and no change in distribution or abundance. Any mortality will be replaced through natural recruitment from the next generation. The principal cause of impacts is spilled oil.

In Alaska, routine activities should have no measurable effect on salmon. Oil spills contacting migratory salmon populations could have adverse impacts on small groups. The numbers affected should be small in proportion to the total, and any oil spill should have only a small-scale, small-area, and short-time effect.

The level of oil and gas exploration and development is not likely to have an appreciable effect on groundfish populations, or on arctic ciscoes that migrate at some depth in the nearshore waters of the Beaufort Sea. Alaskan regional shellfish populations might be displaced from very small habitat areas by drilling discharges and offshore construction. No appreciable effect on regional shellfish populations should occur.

In the Gulf of Mexico, the effect on fish resources from routine operations should be undetectable on estuary-dependent species such as menhaden, shrimp, blue crabs, sciaenids, mullet and oysters, to pelagic species such mackerels, cobia, bluefish, amberjack, and dolphin fish, and to reef fish species such as grouper, snapper, scamp, and sea bass. Any loss of fish resources should be replaced through natural recruitment from the next generation. The principal cause of impacts is spilled oil. An oil spill contacting a Gulf estuary could result in both lethal and sublethal effects on menhaden, shrimp, blue crabs, and sciaenids that use the area contacted by the spilled oil as a nursery and/or spawning ground. The effects from chronic oiling in Gulf

coastal wetlands is likely to be lethal to all contacted pelagic stages of a sessile fishery resource such as oysters and render any contacted adult oysters unmarketable due to tainting.

Along the Pacific coast, Alaskan tanker oil spills could result in lethal or sublethal effects locally in the area of contact. Oil entering the mouth of a spawning stream on the northern Pacific Coast could cause mortalities to hundreds of migrating individuals of anadromous species (primarily salmon) affecting the year class for 2-4 years. Regionally, lethal or sublethal effects would not be discernible from natural variations of fish populations within the area.

g. Impacts on Reptiles

No discernible decline in marine turtle populations and no change in distribution or abundance are predicted. Any deaths should be replaced through natural recruitment from the next generation. Any sublethal effects should last less than one generation.

The primary effects on wetland-estuarine habitats in the Alaska Region are expected to come from a causeway, pipeline-landfall construction, and oil spills. Hydrological effects from the causeway could have some effects (perhaps 5-10 percent) on the distribution of species (anadromous fishes) and could last for more than 10 years. The side effects of turbidity from pipeline burial on wetland-estuarine habitats should be short term, lasting less than 2 years. Oil spill contamination of wetland-estuarine habitats could have local adverse effects on the biological diversity or productivity of invertebrate communities lasting for more than 10 years.

Wetlands along the coast of the Gulf of Mexico could be eroded along navigation channels as a result of vessel traffic. The proposal could result in one growing season dieback of wetlands if contacted by spilled oil. Some of these areas could be converted to open-water habitat if higher concentrations of oil result in plant mortality and eventual land loss. Most impacts should occur along the Louisiana and north Texas coastal areas. Barrier beach configurations should not be altered significantly beyond existing trends in very localized areas downdrift from jettied or artificially maintained navigation channels. Strategic placement of dredged material resulting from channel maintenance, channel deepening, and related actions can mitigate adverse impacts upon those localized areas.

On the Pacific coast, a spill could occur from tankers carrying Alaska OCS or non-OCS crude oil. If a tanker spill occurred and it entered wetlands and estuaries, it could cause destruction of a major part of the local biological community, either of the entire estuary or those portions where oil has soaked into the sediments. Recovery could require 5 or more years. Regional impacts of a spill could involve a decrease of several populations in local estuarine communities, but with no real interference with ecological relationships in the region.

i. Impacts on Seafloor Habitats

In the Beaufort sea, oil-spill effects on the productivity and diversity of the Boulder Patch benthic organisms could persist for 2 years. Turbidity and sedimentation effects on the growth and productivity of benthic organisms of the Boulder Patch from nearby pipeline burial and causeway construction could persist for about 2 years.

In the Gulf of Mexico, there should be little damage to the widespread, low-density chemosynthetic communities. The rarer, high-density "Bush Hill" type chemosynthetic communities are most susceptible to damage from physical disturbance, but they too should suffer little or no damage. If physical disturbance (such as anchor damage) to high-density communities were to occur despite mitigation, impacts could be severe over a limited area, with recovery times as long as 200 years for mature tube worm communities. There could be losses of productivity, reproduction, community relationships, and overall ecological functions of the community, and the surrounding benthos.

There should be little or no damage to the habitats on the topographic features in the Gulf of Mexico. Small localized areas could be impacted by operational discharges. In the unlikely event of a seafloor blowout, a recovery to pre-impact condition should take less than 2 years. Impacts to other live-bottom communities should be minor in scope and primarily sublethal in nature. If physical disruption (anchor placement) were to occur, impacts could be severe over a limited area, with recovery to pre-impact conditions taking 5 to 10 years.

In Alaska, impacts on sociocultural systems should be centered predominantly within the Arctic communities of the North Slope Borough and North Aleutian Borough and Northwest Arctic Borough, primarily because of impacts to subsistence harvests from oil spills. Disruption of Inupiat subsistence harvests, especially of the bowhead whale, would disrupt task groups, crew structures, and sharing networks among kinship groups and communities. If large oil spills occurred, a dramatic increase in social stress could occur in the communities affected, producing an extreme sense of loss and dislocation that could persist for 2 or more years. Changes in subsistence harvests elsewhere in Alaska from oil spills should not last more than 1 year, with effects to the sharing networks and task group structures likely to be small and intermittent, although tensions and anxieties caused by the disruptions may last for a longer period of time.

In the Gulf of Mexico, all or most of the employment should come from those currently employed in OCS-related oil and gas activities as well as the unemployed and underemployed, and new employees already living in the area. While large-scale in-migration is not likely, it remains possible that a community (or communities) closely affiliated with OCS activity may gain residents as a result of the proposal with concomitant impacts to cultural homogeneity, community cohesion, and quality of life in some specific cases. The extended work schedule could result in deleterious effects on family life in some individual cases. Impacts caused by the displacement of traditional occupations and relative wages could occur to a limited extent. Impacts on Fisheries

k.

In Alaska waters, offshore oil and gas operations could cause disruption to some commercial fishing activities. Operations could cause a loss of catch and loss of direct employment, and damage or loss of fishing gear. A large oil spill could result in a region-wide loss of $9-43 million/year to the commercial fishing industry for 2 years following the spill. This assumes that the spill occurs during the commercial-fishing season and in an area where it adversely affects commercial fishing.

In the Gulf of Mexico, an economic loss to commercial fisheries of the estuary dependent species such as menhaden, shrimp, blue crabs, mullet, and oysters could occur for one to two fishing seasons, principally because of oil spills. Large oil spills could temporarily disrupt fishing activities in the offshore areas directly impacted, and could lead to a decline in the sale of fishing equipment, supplies, and services for up to one fishing season (6 months) when large quantities of oil pollution come ashore near a coastal fishing community.