An oil spill is the release of oil (generally, petroleum) into the natural environment, usually the ocean. Oil means oil of any kind or in any form and includes crude oil, oil refuse, petroleum-related products or by-products, oil mixed in waste, oily ballast, and oily bilge water.

Studies of the effects of the Exxon Valdez oil spill have shown that the environmental damage caused by oil spills is greater than was previously thought. It is now thought that the impact on marine life can be serious at less than one part per billion of pollution.

Oil can also be washed up on beaches, requiring a large amount of work to be cleaned up. Birds can also get oil stuck in their feathers, which can render them flightless unless washed. The oil can also poison them if they attempt to prean their feathers.

Heavier components of crude oil, such as polynuclear aromatic hydrocarbons (PAHs) appear to cause the most damage; while they are relatively unreactive they persist in the water much longer than volatile components such as toluene.

Oil spill incidents

• Torrey Canyon, South England, March 18 1967
• Amoco Cadiz (BP/Amoco, USA) - Britanny, France, March 16 1978
• Exxon Valdez (Exxon, USA) - Prince Williams Bay , Alaska, March 24 1989
• Braer - Shetland Islands, January 1993
• Sea Empress - Wales, February 1996
• Erika - Bay of Biscay, 1999
• Prestige - Galicia, Spain, November 13 2002
• Tasman Spirit, Karachi, Pakistan, July 28 2003
• Selendang Ayu, Unalaska Island, Alaska, December 8 2004

See also

• penguin sweaters