It has been 15 years since the Exxon Valdez oiled Alaska's Prince William Sound, and more than 12 since the last of the official restoration workers took off their orange slickers and headed home. But at least one cleanup crew never left the Sound: sea otters. The creatures, which were hit especially hard by the first effects of the spill, continue to feed on clams and other food in areas that still contain pockets of oil. Their diligent digging is helping release trapped petroleum--which appears to be sickening them. Ecologists are left with a dilemma: remove the oil (and possibly cause more harm to the Sound) or let the animals continue to do the dirty work and pay the price.
Scientists had originally predicted that any remaining oil would have been carried by waves to shorelines by now. There exposure to air would transform the oil into a hardened asphalt residue lacking the more volatile and toxic components. "The assumption was that the oil wasn't subsurface, it wasn't low, it was up there in that 'bathtub ring,' and that's where the cleaning effort was focused," explains Stanley D. Rice, a laboratory program manager with the National Oceanic and Atmospheric Administration's Alaska Fisheries Science Center in Juneau.
This article was originally published with the title The Oil and the Otter.