The Infamous Exxon Valdez

Shortly after leaving the Port of Valdez, the Exxon Valdez ran aground on Bligh Reef in Prince William Sound, Alaska. This photo was taken three days after the vessel grounded, just before a storm arrived, making the situation even worse. (Photo credit: OR&R, NOAA)

A lot can go wrong on the open sea. Heavy seas can drive a ship into dangerous waters. A miscalculation can cause ships to collide or begin a chain of events leading to an explosion or fire. An engine can falter, leaving a heavily loaded tanker to drift toward a rocky shore or reef. Just such an event occurred on March 24, 1989. En route from Valdez, Alaska, to Los Angeles, California, the tanker Exxon Valdez grounded on Bligh Reef in Alaska’s Prince William Sound, rupturing its hull and spilling nearly 11 million gallons of crude oil into this remote, scenic and biologically productive body of water. The ship was traveling outside normal shipping lanes in an attempt to avoid an iceberg. The oil eventually affected over 1,100 miles of the Alaska coastline, making it the largest oil spill to occur in U.S. waters to date.

Oiled duck on the shore following the Exxon Valdez oil spill. (Photo credit: Exxon Valdez Oil Spill Trustee Council)

The images that Americans saw on television and descriptions they heard on the radio that spring were of heavily oiled shorelines, dead and dying wildlife, and thousands of workers mobilized to clean beaches. These images reflected what many people felt was a severe environmental insult to a relatively pristine, ecologically important area that was home to many species of wildlife endangered elsewhere. In the weeks and months that followed, the oil spread over a wide area in Prince William Sound and beyond, resulting in an unprecedented response and cleanup—in fact, the largest oil spill cleanup ever mobilized. Many local, state, federal, and private agencies and groups took part in the effort. Even today, scientists continue to study the affected shorelines to understand how an ecosystem like Prince William Sound responds to, and recovers from, an incident like the Exxon Valdez oil spill.

To learn about how Prince William Sound is recovering from the Exxon Valdez oil spill, NOAA scientists have been conducting a monitoring study since 1990 (the year after the spill). They chose about 20 study sites around Prince William Sound, including (1) sites that had been oiled by the spill, but not cleaned up, (2) sites that had been oiled and cleaned, and (3) sites that were not oiled, which served as their control.