From BirdWatching in the USA:
Scientists study how loons and white pelicans fared in Gulf oil spill
Posted Tue, Aug 23 2011 4:49 PM by Matt Mendenhall
A research project initially intended to study why Common Loons contract botulism in Lake Michigan during fall migration has been expanded to gauge the potential impacts of the BP oil spill on loons and American White Pelicans.
The birds breed in the Upper Midwest and spend winters on or near the Gulf of Mexico. The spill hit Brown Pelicans, Laughing Gulls, and other Gulf-resident birds hardest, but loons, American White Pelicans, and several other migratory species were also affected. According to the most recent official numbers from the U.S. Fish and Wildlife Service, 75 Common Loons were collected, including 61 that died. Of 19 American White Pelicans collected, 13 died.
See also here.
Report Released Analyzing Toxicity of Dispersants Used In Gulf Oil Disaster: here.