Shortly after midnight on March 24, 1989, The Exxon Valdez impaled itself on Bligh Ref in Alaska’s Prince William Sound. The tanker leaked 38.800 metric tons of crude oil, fouling 1,300 miles of coastline and wrecking the local fishing industry. During the next 20 years, Exxon spent more than two billion dollars on cleanup and lawsuits.
Teh accident served as a rallying cry for environmentalists and prompted the U.S. and other nations to implement stricter standards for cargo vessels in their waters. In 2010 a UN phaseout of single-hulled tankers, like the Valdez, in which a single street plate separates cargo from sea, will take full effect. Improvements such as better radar and broad us of GPS navigation have also reduced mishaps.
Scientists struggle to learn how much oil enters the oceans each year. The National Reaserch Council estimates 1.3 million metric tons, with tanker spills making up 8 percent. Perhaps the most surprising contributor is Mother Earth, with seepage from natural deposits accounting for as much as 46 percent.