A number of coastal parks and wildlife refuges that are important to marine and coastal birds and to a wide variety of wildlife in general exist in the mid-Atlantic region. Assuming that a spill has occurred, there is an 11 percent or less (sale area spill) and a 7 percent or less (Sale No. 111 tanker spill) probability that it will reach a Federal, State, or private wildlife refuge along the mid-Atlantic coast. Oil spill containment and cleanup equipment will be available to reduce or prevent losses to birds and their habitats (see Section IV.C.), but some losses should be expected if a spill occurs and reaches the shore.

The probabilities of oil spills occurring and adversely affecting coastal birds and their habitats from all sale-related activities over the life of the field are listed in Table 12 of Appendix C. The highest probability of contact is only 4 percent to both coastal waterbird colonies and sea duck wintering areas. This low probability indicates that it is very unlikely that the proposed sale will pose a serious oil spill threat to coastal birds and their habitats. This low oil spill risk in addition to the distance between the sale area and land (over 50 miles) and the anticipated low level of OCS onshore development suggests that the proposed sale should have only a minor impact on coastal birds.

Conclusion: The proposed sale could have a minor impact on marine and coastal birds and their habitats occurring in the mid-Atlantic region.

Cumulative Impacts

Activities associated with existing mid-Atlantic OCS leases will have a cumulative effect on marine and coastal birds with impacts anticipated from the proposed action. The number of wells drilled and the amount of drill muds and cuttings discharged would increase. The probability of an oil spill occurring would also increase from production on the mid-Atlantic OCS. factors could have an adverse effect on marine birds, primarily. The number of gas pipelines and their associated landfalls and onshore gas processing plants would increase from 1 (proposal only) to 2 (proposal plus existing leases). This increase in OCS facilities in the coastal zone would have a negative effect on coastal waterbirds and possibly their onshore habitats depending upon where the facilities are located. Therefore, the cumulative effect of existing and proposed OCS activities in the mid-Atlantic on marine and coastal birds could result in a moderate level of impact on these sea birds.

Because crude oil recovered from the north and south Atlantic OCS regions is expected to be transported to refineries in the mid-Atlantic region, OCS development in these areas could have a cumulative effect on birds and their habitats occurring in the mid-Atlantic area. A tanker carrying crude oil from the South Atlantic could spill oil on marine and coastal birds, shorebirds and waterfowl particularly in the Chesapeake and Delaware Bays or along the Delaware, Maryland, and Virginia coasts. In addition, because many sea birds migrate, they may be exposed to impacts occurring in adjacent OCS regions. Therefore, when OCS development in the north, south, and mid-Atlantic are considered, the impact to sea birds and their habitats increases.

Impacts that are not related to OCS activities, but could contribute to a cumulative impact on avian resources include the loss of nearshore and onshore habitats from private and recreational development. This will pose a serious threat to wading birds and shorebirds in particular. Those species which migrate

as far as Central and South America could be exposed to toxic substances which

are widely used, like DDT, that will inhibit reproduction.

Industrial and sewage sludge wastes from designated ocean dumpsites could have an adverse affect, especially on marine birds, by degrading the ocean environment. Marine birds will also be exposed to oil spills from oil imported into the north and midAtlantic regions. An estimated 27 spills over 1,000 barrels each may occur over a 25-year period from oil imported into the region (Table 1, Appendix C). If this large number of spills actually does occur, populations of marine and coastal birds would suffer severe declines. However, transcontinental migratory species are protected and managed in accordance with international treaties. These treaties do provide a measure of protection to international migrants by requiring signatory nations to promote the conservation of these species.

Conclusion:

The cumulative impacts from proposed and existing OCS lease offerings in the mid-Atlantic region, in adjacent regions and from non-OCS-related activities, could pose a major threat to sea bird populations inhabiting the sale area.

IV.E.4. Impacts on Sensitive Coastal Habitats

The types of impacts that could occur to sensitive coastal areas (e.g. bays, estuaries, coastal marshes, and beach-dune areas) from oil spills are quite numerous because of the complexity of these biologically fragile habitats. If an oil spill were to enter or occur in a major estuary, the immediate result would be a temporary drop in water quality that would have the greatest effect on planktonic organisms. Oil would probably strike the shoreline and become incorporated in the bottom sediments. Incorporation of oil into the sediments will retard degradation of the oil and could cause contamination to remain for up to 10 years (Boesch, Hershner and Milgram, 1974), and lead to serious long term impacts to benthic organisms. Water flow patterns in estuaries tend to make them act as nutrient and pollutant traps (Odum, 1970), thus preventing spilled oil from being flushed from the system. This could increase the amount of exposure of many estuarine plants and animals to spilled oil. The effects of an oil spill on the many resources that utilize these areas such as bird species, commercial fisheries and shellfish, and other aquatic invertebrates are addressed in Section IV.E.

Wetland vegetation bordering estuarine and coastal shorelines, including salt marshes, could be adversely affected by an oil spill. Generally, oiled vegetation dies but the roots and rhizomes remain viable when a spill is not too severe (Burns and Teal, 1971). Chronic pollution will have more serious effects. A marsh near a refinery effluent was reported to be completely denuded by chronic low-level pollution (Baker, 1971). The impacts of oil on marsh plants is further dependent upon the season (growing versus dormant) in which a spill might occur. Damage would be greatest during the spring and summer growing seasons. Since aquatic vegetation plays such a vital role in maintaining the stability of estuarine and marsh ecosystems, the permanent loss of vegetation would result in a corresponding decay of these systems.

The probability of an oil spill from the sale area reaching the Narragansett, Raritan, Delaware, or Chesapeake Bays within 30 days assuming a spill has occurred is 3 percent or less (see Table 8 of Appendix C). However, the probability of an oil spill from the sale area reaching coastal marshes is 8 percent or less. The deployment of oil spill cleanup equipment should further

restrict an offshore oil spill from entering any bay or inlet in the region or coastal wetland. In addition, after 30 days the oil should be extensively degraded due to weathering.

Tanker accidents could result from Sale No. 111 tankers servicing the lease area. Because the tankers would be bound for refineries in the Delaware and Raritan Bays, tanker spills could occur and adversely affect the extensive fish, wildlife, and wetland resources bordering the entrance to and the shoreline of these bays (see Visual No. 1). Assuming that a Sale No. 111 tanker spill has occurred, there is a 20 percent or less probability that it will contact a coastal marsh within 30 days, suggesting that a tanker spill resulting from the proposed sale will pose a moderate threat of contact to coastal marshes.

In Narragansett Bay, three islands and their surrounding waters have been designated an estuarine sanctuary. Although an oil spill in this sanctuary would jeopardize most of the existing sanctuary uses and wildlife resources, it is extremely unlikely that an oil spill would penetrate so far up the bay as to affect the sanctuary (see Visual No. 1). Service vessels operating out of Davisville, Rhode Island, are not expected to transit sanctuary waters. Nantucket Shoals is an area of shallow water (generally less than 50 m) located east and south of Nantucket Island. An oil spill in these waters would pose a serious threat to the rich fishery resources, marine mammals (seals and small cetaceans), and sea birds that are abundant in the area. However, the probability of a sale-related spill entering these waters assuming one has occurred is very low (3 percent or less). Therefore, considering this low oil spill risk, distance from the sale area and absence of support facilities in the area, the proposed sale should not pose a serious threat to Nantucket Shoals. The North Carolina estuarine sanctuary sites (Carrot Island complex and Zeke's Island complex) are also environmentally sensitive coastal areas that could be seriously affected by an oil spill or from onshore development. However, the threat of an oil spill contacting these areas assuming one has occurred is very low (less than 0.5 percent) Table 8, Appendix C) and no onshore facilities will be located in these areas.

The Cape and Islands Ocean Sanctuary of Massachusetts promotes, among other things, the protection of ecologically significant marine and coastal resources. The probability of an oil spill from the proposed lease area entering this ocean sanctuary is 29 percent or less and 18 percent or less from a Sale No. 111 tanker spill. This indicates that a spill from either the lease area or a tanker could pose a significant threat to the marine and coastal resources included in the sanctuary should a spill actually occur.

The beach-dune region of the mid-Atlantic consists of a narrow strip of land essentially lining the entire mid-Atlantic coast. An oil spill reaching land could destroy dune grass (needed to stabilize the beach), saturate the sand, and require mechanical removal of contaminated sands. The removal of sand by heavy equipment would contribute further to the destruction of the beach-dune area. Assuming that a spill from the sale area occurs, there is a 34 percent or less probability that it will reach land (see Table 5 of Appendix C). However, the probability of a Sale No. 111 tanker spill reaching land increases to 47 percent with Long Island, New York and Monmouth County, New Jersey facing the highest risk. These probabilities indicate that there is a greater risk of loss of beach-dune habitat from Sale No. 111 tanker spills than from spills within the sale area should a spill actually occur.

The Assateague/Chincoteague barrier island is a pristine natural area that is located approximately 50 mi from the boundary of the proposed sale area (see Visual No. 1). If an oil spill from either a tanker or platform occurred, there is a 2 percent or less probability that it would reach the island. Also no support facilities are anticipated in the vicinity of this pristine area. Therefore, the proposed action should have only a negligible impact on the Assateague/Chincoteague barrier island.

In general, oil spills resulting from Sale No. 111 tanker accidents as opposed to oil spills from the sale area would pose the greatest risk to sensitive coastal areas assuming a spill has occurred. However, impacts to these sensitive habitats will tend to be relatively shortlived due to the natural breakdown of oil in the marine environment and to oil spill containment and cleanup operations required under OCS Operating Order No. 7 (see Appendix D). Cleanup facilities and contingency plans for the mid-Atlantic region are described in more detail in Section IV.C. Oil that becomes trapped in bottom sediments can pose a long-term threat primarily to benthic organisms that are dependent upon these habitats.

The probability of an oil spill greater than 1,000 barrels occurring and contacting land within 30 days over the life of the field is 7 percent (Table 12, Appendix C). The probability of a spill under these same conditions contacting coastal marshes, wildlife refuges, and other natural areas is even less. These low probabilities indicate that it is very unlikely that activities associated with the proposed sale will pose a serious oil spill threat to sensitive coastal habitats. This low oil spill risk in addition to the distance between the sale area and land (over 50 miles) and the anticipated low level of OCS onshore development suggests that the proposed sale should have only a negligible impact on sensitive coastal areas.

Activities associated with pipeline burial and the construction of onshore facilities can adversely affect coastal areas. Impacts to barrier beaches originate from trench excavation through unstable sands and sediments that are prone to erosion when disturbed. However, the sides of the trench are usually retained by sheet-piled coffer dams to avoid any serious erosion problems during trenching. Impacts are further mitigated because the period needed for construction is short and because of the relative ease of refilling the trench (10 to 40 ft in width). Dune vegetation existing landward of the beach will be destroyed in the pipeline right-of-way (up to 300 ft in width) during construction activities. Proper reclamation and management practices should permit vegetation to re-establish itself in the operational right-ofway (40 to 50 ft in width).

Large diameter pipelines crossing coastal wetlands will require a right-ofway width of about 150 ft and a trench 8 to 10 ft wide and 4 to 6 ft deep during the construction period if the push-ditch method is used (Golden et al., 1980). This is the preferred method from both the ecological and economical standpoints. However, it may take several years after the trench has been refilled and vegetation replanted for the wetlands to return to their original state. One gas pipeline may be required to bring gas ashore as a result of proposed Sale No. 111 (see Appendix B). Impacts would be restricted to the period of right-of-way construction and pipeline burial. Sandy beach areas would be disturbed at each landfall and possibly some coastal wetland areas. However, no significant long-term impacts should result assuming restoration of each right-of-way.

Conclusion: The proposed sale should have a negligible impact on the sensitive coastal areas of the mid-Atlantic region, including all current estuarine sanctuaries.

Cumulative Impacts

Activities associated with existing mid-Atlantic OCS leases will have a cumulative effect with impacts anticipated from the proposed action. The probability of an oil spill occurring would increase from production on all the mid-Atlantic OCS. This would increase the oil spill risk to the coast. However, none of the existing leases are within 50 miles of land. The number of gas pipelines and their associated landfalls and onshore gas processing plants would increase from 1 (proposal only) to 2 (proposal plus existing leases). This increase in OCS facilities in the coastal zone would have a negative effect on sensitive coastal habitats depending upon where the facilities are located. Therefore, the cumulative effect of existing and proposed OCS activities in the mid-Atlantic could result in a moderate level of impact on sensitive coastal habitats.

An estimated 3 oil spills greater than 1,000 barrels each may occur from proposed and existing OCS lease sales in the adjacent north and south Atlantic regions. The cumulative effect of OCS oil and gas activities from all three regions combined could result in the degradation of several near-shore and coastal areas ranging from Martha's Vineyard to Cape Hatteras, North Carolina. However, the impacts on these sensitive habitats will tend to be relatively short-lived because oil breaks down naturally in the marine environment, and oil spill containment and cleanup operations are required under OCS Operating Order No. 7. Toxic hydrocarbons that might become trapped in bottom sediments or sink areas could pose a long-term (over 5 years) threat as oil trapped in sediments degrades very slowly and may be resuspended in the water column disturbed (Sanders et al., 1980). Oily sediments can have a deleterious effect on marine benthos.

Cumulative impacts from onshore support facilities, including gas processing plants, gas pipelines, and supply bases, should be minimal as support facilities are expected to be located in existing industrial areas or rightsof-way. A total of 27 spills from crude oil imports and refined products could occur in the mid-Atlantic region over a 25-year period (see Table 1 of Appendix C) have a very high probability of occurring and adversely affecting many coastal resources (see Table 15 of Appendix C). Private and recreational development of sensitive coastal areas also pose a serious threat to these

resources.

Conclusion: Cumulative impacts from all sources will have a major impact on sensitive coastal habitats in the mid-Atlantic region.