Recovery Status of Barrow's Goldeneyes. EXXON VALDEZ Oil Spill Restoration Project Final Report. Restoration Project 00466.

摘要

Barrow's goldeneye (Bucephala islandica) population recovery from the Exxon Valdez oil spill was evaluated by examining potential constraints to recovery including food limitation, demographic limitations to population growth, and continued exposure to oil. Food abundance likely did not limit Barrow's goldeneye population recovery. Although mussel (Mytilus trossulus) biomass was greater on unoiled Montague Island than oiled Knight Island, body mass and nutrient reserves were similar or larger on Knight Island. Demographic data were mixed regarding recovery status. Densities of Barrow's goldeneyes did not differ between oiled and unoiled areas after accounting for habitat effects, consistent with full popularity recovery. However, marine bird surveys indicated different population trends between oiled and unoiled areas, with increasing densities on unoiled areas and stable densities on oiled. Continued oil exposure through 1997 was indicated by higher induction of cytochrome P450 1A in birds from oiled areas than unoiled. Further, elevated hydrocarbon levels in intertidal sediments and mussels in 1999 indicate potential mechanisms for continuing exposure. However, little evidence indicated physiological or population-level consequences of this exposure. Most data suggest population recovery or at least no strong residual effects, although additional demographic data would allow for a more critical evaluation of that conclusion.