The study, by research chemist Jeffrey Short and colleagues at the National Marine Fisheries Service in Juneau, Alaska, is also scheduled to appear in the June 15 print issue of the journal.
"This study shows that it is very plausible that exposure to Exxon Valdez oil is having a material impact on many shore-dwelling animals and is contributing to their slow recovery in some parts of Prince William Sound," Short says. "Sea otters, for instance, have yet to re-inhabit Herring Bay, the most oiled bay we studied, and the population of otters elsewhere around northern Knight Island continues to decline. Unfortunately, because much of this oil is buried in beach sediments and not exposed to weathering and other elements that might degrade it, it could remain hazardous to wildlife for decades."
The Exxon Valdez stuck an underwater rock formation on March 24, 1989, spilling 11 million gallons of heavy crude oil into the Sound over the next several days. Despite massive clean-up efforts, Short estimates about six miles of shoreline is still affected by the spill and as much as 100 tons of oil lingers in the Sound.
In their study, Short and his colleagues found significant amounts of Exxon Valdez oil buried in sand and silt that only becomes dry during the lowest tides. This biologically diverse zone is a prime feeding ground for sea otters, ducks and other wildlife.
Previously, scientists believed most of the oil was deposited on beaches at higher tide levels.>