Evaluating Harlequin Duck Population Recovery: CYPI1A Monitoring and a Demographic Population Model

摘要

The authors found that cytochrome P4501A induction during winters 2005, 2006-07, and 2009 was higher in harlequin ducks captured in areas of Prince William Sound oiled by the 1989 Exxon Valdez spill, relative to unoiled areas. Cytochrome P4501A induction did not vary in relation to age, sex, or mass of individuals, nor did it vary strongly by season in samples collected early and late in the winter. We interpret these results to indicate that harlequin ducks continued to be exposed to residual Exxon Valdez oil up to 20 years after the original spill. Population modeling efforts indicated that female mortality related to chronic exposure to lingering oil was nearly double that estimated during the acute phase (the weeks and months immediately post-spill). Full recovery to pre-spill numbers was estimated to require between 13 and 32 years, with the most likely recovery scenario requiring roughly 24 years. Taken together, the data presented in this report add to a growing body of literature suggesting that effects of oil spills on wildlife have the potential to be expressed over much longer time frames than previously assumed.