Mechanism of impact and potential recovery of pigeon guillemots (Cepphus columba) after the Exxon Valdez oil spill

Abstract

The abundance of pigeon guillemots in oiled areas of Prince William Sound, Alaska, failed to increase after the 1989 Exxon Valdez oil spill. Population growth may be constrained by the physiological effects of oil exposure, food availability, and nest predation." The author "conducted a comparative study among unoiled, oiled, and pre-spill data sets, to provide insight on factors limiting population recovery in oiled areas. Blood samples from chicks in oiled and unoiled areas provided little evidence of physiological effects of exposure to oil. Pigeon guillemot diet, productivity, growth rates, and fledging weights in unoiled areas of southwestern Prince William Sound from 1994 to 1998 indicate oiled areas had a lower proportion of high-lipid fish in the chick diet and lower fledging weights, compared to unoiled and pre-spill studies. These results suggest that the lack of recovery in oiled areas is associated with a prey base that results in lower fledging weights, which may reduce juvenile survival.