Exxon Valdez oil persists off Alaska

Lingering crude from the largest US oil spill has resisted weathering in some places almost 18 years after the tanker Exxon Valdez ran aground and fouled hundreds of miles of Alaska shoreline, a new federal study concludes.

The estimated 77 tonnes – or more than 26,600 gallons – of oil remaining at Prince William Sound is declining by about 4% a year and likely even slower in the Gulf of Alaska, according to research chemist Jeffrey Short of the National Oceanic and Atmospheric Administration.