From:

Esler, D., J. A. Schmutz, R. L. Jarvis, and D. M. Mulcahy. 2000. Winter survival of adult female harlequin ducks in relation to history of contamination by the Exxon Valdez oil spill. Journal of Wildlife Management 64:839-847.

We used radios in adult female harlequin ducks to determine if survival was different between an area that was oiled by the 1989 Exxon Valdez spill and a nearby unoiled area. Based on 294 radioed birds, we found that survival in oiled areas was 6-10% lower in oiled areas. We also determined that this difference resulted in declining numbers of birds on oiled areas. Based on evidence that harlequin ducks continued to be exposed to oil through at least 1998, we speculate that the difference in survival between areas was related to continued exposure to Exxon Valdez oil.