Monitoring Beaufort Sea Waterfowl and Marine Birds, Aerial Survey Component.

摘要

We investigated disturbance effects of human activities on the distribution and density of Long-tailed Ducks (Clangula hyemalis), and eiders (Somateria spp.) in lagoons and offshore waters of the south-central Beaufort Sea from 1999-2000. To achieve this, we conducted 12 replicate Near-shore aerial surveys between Oliktok Point and Brownlow Point, and compared our results with historic data collected in 1990-1991. We also conducted 6 Offshore aerial surveys between Cape Halkett and Brownlow Point, Alaska to document offshore distribution of marine birds. We observed 33 marine birds taxa on Near-shore and Offshore surveys combined. A comparison between 1990 and 2000 revealed a significant negative trend in density of Long-tailed Duck with the Near-shore survey area. Although densities decreased overall, trends in density were the same among 'Industrial' and 'Control' transects. Distribution patterns were not significantly related to sources of potential disturbance such as boat traffic, low-level aircraft over-flights, or human activities on shore adjacent to survey transects. We identified several areas that appear to be important to marine birds including Harrison Bay; barrier island habitat, particularly among the Stockton Islands; and mid-lagoon habitat in western Simpson Lagoon.