The Exxon Valdez oil spill occurred on March 24, 1989 when an oil tanker grounded on a reef in Alaska’s Prince William Sound. It spilled almost 11 million gallons of crude oil, which reached 1,300 miles of coastline. The spill's remote location, accessible by air or boat only, made the restoration response all the more difficult. Seabirds, mammals, fish, invertebrates, and their communities were all affected by the oil, and 25 years later there is still oil in the ecosystem. It is difficult to determine the true cost of a spill like this without a price tag for how much animals in a remote location are worth. But Richard Carson, a natural resource economist, led a team that determined just that. Learn about how it is done in an interview with the Ocean Portal.