The grounding of the Exxon Valdez, which 12 years ago leaked 11 million gallons of crude oil into Prince William Sound, wasn't the worst oil spill in history. "The Ixtox 1 exploratory blowout of 1979 spilled an estimated 140 million gallons of oil into the ocean" (OceanMatters). But the Exxon Valdez led to new safety standards for sea borne oil transport. Many factors complicated the cleanup efforts following the spill. The remote location of the spill and its size, accessible only by helicopter and boat, made efforts difficult and tested existing plans for dealing with such an event. "The spill threatened the delicate food chain that supports Prince William Sound's commercial fishing industry. Ten million migratory shore birds and waterfowl, hundreds of sea otters, dozens of other species, such as harbor porpoises and sea lions, and several varieties of whales were also in danger" (EPA).