IMPACT OF OILFIELD DEVELOPMENT ON SHOREBIRDS, PRUDHOE BAY, ALASKA (HABITAT LOSS)

Oilfields cover about 2,300 km2 of wetlands on Alaska's Arctic Coastal Plain and further development is planned. Environmental effects of oilfield development are evaluated by several resource agencies that must consider impacts on birds and other biota. This study analyzes three sources of development impacts on six shorebird species in the Prudhoe Bay Oilfield to estimate the overall effect of the oilfield.; Developmental effects on birds were attributed to three sources: primary--direct habitat loss due to gravel placement, secondary--habitat loss due to physical disturbances associated with gravel fill, and an hypothesized third source due to landscape fragmentation by the road and facility network. Potential reductions due to primary and secondary sources were assessed with a model that related habitat loss and shorebird density by habitat type. The third source was assessed by comparing bird densities in the oilfield to those in a control area.; Six common breeding shorebirds in the area: Semipalmated Sandpiper (Calidris pusilla), Pectoral Sandpiper (Calidris melanotos), Dunlin (Calidris alpina), Lesser Golden-Plover (Pluvialis dominica), Red Phalarope (Phalaropus fulicaria), and Red-necked Phalarope (Phalaropus lobatus); were studied. Habitat lost or altered in the oilfield due to primary and secondary sources as of 1983 would have supported an estimated 5,200 shorebirds; approximately 5% less than expected if the oilfield was not present. An additional 13% reduction of the shorebird group and an 11% reduction of total nests within the oilfield were estimated for the third source. These data showed no significant relationship between bird density and oilfield density (size of landscape fragments due to the road and facility network). Cumulative effects, estimated by adding the three sources, were an 18% reduction of birds within the perimeter of the oilfield.; The model can be used by resource managers to evaluate relative effects of project alternatives on breeding birds. Data on bird densities in the oilfield show a third source of effect is present due to landscape fragmentation. Further work is needed to extend the applicability of the model to other areas and to test further for the existence of a relationship between facility density and breeding bird density.