Scientists are still finding oil from the 1989 Exxon Valdez spill:
[Gail] Irvine, of the United States Geological Survey, has been monitoring the sound and the coastline of the Shelikof Strait, southwest of the spill, for 20 years, and has just recently discovered these pockets of oil that have persisted behind large boulders along the coastline. What’s more, the oil appears to have broken down very little and has the chemical makeup of oil that is just 11 days old, meaning it isn’t going anywhere anytime soon.
“Every chemist who has looked at this has been surprised,” Irvine said. ”These are at high wave-energy sites, it’s not the kinds of areas where oil would have been predicted to have persisted, especially because it has barely been weathered.”