20 Years After Spill, Valdez Oil 'Harmless'

Nearly 20 years after the Exxon Valdez spill, what little oil remains in the soiled Prince William Sound is harmless to plant and animal life, scientists agree. The last oil deposits remain deep in the cracks between shoreline rocks, inaccessible to animals and degraded enough to be "biologically insignificant." But what scientists don't agree on is whether the site can be categorized as clean, New Scientist reports.

Greenpeace activists say it's too early to assume the residue won't have an ecological or reproductive impact. The local killer whale population, for example, still hasn't recovered from losses in the 1989 spill. ExxonMobil says its settlement has paid for more than $1 billion to investigate the damage to the Sound, and that it's now "healthy, robust, and thriving."
(More Exxon Mobil stories.)