Oil Spills
Oil spills occur when oil is released into the ocean, usually by leaking oil tanks or broken down equipment. If a ships oil tank gets caught on shallow land then the tank can get a hole in it causing oil to escape. Some times strong winds tip oil tanks into the ocean. Most of the time oil spills are caused by human inconsideration or mistakes.
Oil spills cause great damage to animals whose habitat has been wrecked by oil. Many animals including birds, fish, whales, penguins, otters and small organisms like plankton are affected by spills.
This pie graph shows the sources of the oil spills that occurred from 2006-7. The chart below shows which vessels are most responsible for oil spills. |  |
Effects of oil spills Birds
are strongly affected by oil spills. They cannot fly if they are
covered in the liquid because it is too heavy for them. Seabirds that get coated in oil while at sea can drown. Birds will attempt to clean themselves by eating the oil; causing themselves to get poisoned when the oil enters its lungs and liver. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Otters are affected by oil because the liquid ruins their fur. When an otters body gets covered in oil, it clogs air bubbles in the otters fur. The air bubbles help keep the otters warm , so when oil ruins it, they can die from hypothermia. Large amounts of sea otters who were rescued from oil spills have been taken into captivity because they cannot survive in the harsh wild. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ There are several ways killer whales have become endangered, and oil spills are one of them. One way that oil kills whales is because they eat fish that are covered in oil, therefore eating the oil. This oil will then poison the whale causing them to die. Another way is when the oil clogs the blowhole of a whale causing it to suffocate. The blowhole helps whales to breath when they rise to the surface. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Spills
affect smaller organisms like plankton, larval
fish, seaweed, clams, mussels, oysters and bottom dwelling organisms. If large amounts of the smaller organisms die or become extinct then the food chain is under threat. For example; if plankton died, then they're predators such as fish die from starvation, and then they're predators will starve, and so on. |    |
One of the worst oil spills occurred on March the 23rd in 1989 at Prince William Sound in Alaska. Icebergs lay in there chosen route so they veered of course. On there new pathway they hit a reef, causing the oil to pour out.
The spill harmed many animals including sea otters, harbour seals, bald eagles, killer whales, salmon and sea birds. Approximately 2,800 otters, a minimum of 250,000 sea birds and millions of salmon died because of the accident. Even after 10 years animals and the shore line was still recovering from the disaster. Even today you could dig a small hole and find oil.
Exxon Valdez spilt 40 million Litres of oil, which is capable of filling 125 Olympic sized swimming pools. The spill spread to about 28,000km2.
 This spill is being cleaned by using boiling, chemical water. Dispersant s or other liquids can be used to break down the oil and help it to biodegrade quicker.
 | However, the reason the spill was so bad was not because of the amount of oil released, it is because of the inaccessibility of the location (only helicopters and boats could get there). This slowed the cleaning progress down considerably, and making matters worse was a storm that pushed the oil into the rocky shores. It cost billions of dollars and over 10,000 workers including volunteers, army, navy and air force personnel helped to clean the spill. There a few ways to clean oil spills, including collecting the oil off the surface using skimmer equipment. Boomers are used to contain oil once it is spilled. (below)  |
A current oil spill in the Timor sea has spread to over 6,000 square km and there is already evidence of affected animals. The spill occurred on the 24th of August at the west atlas rig seven hundred km from Darwin
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