Trustee Paper

Harlequin Duck Population Recovery Following the 'Exxon Valdez' Oil Spill: Progress, Process, and Constraints

• Estler’s study lasted from 1995 to 1998 looking at the recovery of the harlequin duck.

• The study evaluated potential constraints on full recovery such as residual oil, food limitation, and intrinsic demographic limitations on population growth rates.

• They conducted their study by synthesizing the findings of their work and other research done on the harlequin duck to evaluate the species.

• Their results found that the harlequin duck population had not fully recovered by 1998.

• They based their conclusions on several factors such as fall population surveys providing number declines in oiled areas and adult female winter population was lower in oiled areas meaning there was still exposure to oil in 1998

Exxon Paper

​Applying Ecological Risk Assesment to Environmental Accidents: Harlequin Ducks and the Exxon Valdez Oil Spill

• The author used ecological risk to framework his finding on the population effect of the Exxon oil spill.

• Ecological risk was used to clarify the cause and effect relationship caused by the oil spill 

• The article claimed that after four years there was only a tiny fraction of the oil spill left

• The results found that none of the 25 species of birds analyzed exhibited delayed effects in occupying previously oiled areas

• There was no significant relationship found between the harlequin ducks and the oiling history of the bays in Prince Williams Sound