"The impacts of an oil spill depend on the size of the spill, the rate of the spill, the type of oil spilled, and the location of the spill. Depending on timing and location, even a relatively minor spill can cause significant harm to individual organisms and entire populations. Oil spills can cause impacts over a range of time scales, from days to years, or even decades for certain spills. On April 20, 2010, an explosion occurred at the Deepwater Horizon drilling platform in the Gulf of Mexico, resulting in 11 fatalities. The incident led to a significant release of oil: according to the federal government's estimate, the well released approximately 206 million gallons of oil before it was contained on July 15. The 2010 Gulf oil spill has generated considerable interest in oil spill governance issues. This report provides background information regarding oil spills in U.S. coastal waters and identifies the legal authorities governing oil spill prevention, response, and cleanup. Based on data between 1973 and 2007, the annual number and volume of oil spills have shown declines-- in some cases, dramatic declines. The 1989 Exxon Valdez spill in Alaskan waters played a large role in stimulating actions that contributed to this trend, particularly the decrease in the annual spill volumes."
CRS Report for Congress, RL33705
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html