Agence France-Presse: Oil from the 1989 Exxon Valdez tanker spill that devastated Alaska’s Prince William Sound still lies trapped beneath its beaches, continuing to pollute once pristine shores, scientists reported Sunday. As climate change opens the Arctic region to oil exploration and shipping, the findings could prove crucial in devising effective methods for cleaning up future spills, the researchers said. Up to now, experts puzzled over why remnants of the 11 million gallons of crude that …