Dr. Rick Steiner, Marine Biologist, University of Alaska, examines oil left from the Exxon Valdez oil spill 15 years later, at Rua Cove on Knight Island Alaska. Greenpeace commissioned photographer Robert Visser, who documented the Exxon Valdez oil spill in 1989, to revisit the disaster site and to photograph oil pollution still in evidence after 15 years.