An oil spill is an accidental release of petroleum hydrocarbons into the environment. On land, oil spills are usually localized and thus their impact can be eliminated relatively easily. In contrast, marine oil spills may result in oil pollution over large areas and present serious environmental hazards.
The primary source of accidental oil input into seas is associated with oil transportation by tankers and pipelines (about 70%), whereas the contribution of offshore drilling and production activities is minimal (less than 1%). Large and catastrophic spills releasing more than 30,000 tons of oil are relatively rare events and their frequency in recent decades has decreased perceptibly. Yet, such episodes have the potential to cause the most serious ecological risk and result in long-term environmental disturbances and economic impact on coastal activities (especially on fisheries and mariculture).
Oil spills affect sea animals such as birds and mammals. The oil penetrates and opens up the structure of the plumage of birds, reducing its insulating ability, and so making the birds more vulnerable to temperature fluctuations and much less buoyant in the water. It also impairs birds' flight abilities, making it difficult or impossible to forage and escape from predators. This and the limited foraging ability quickly causes dehydration and metabolic imbalances. Most birds affected by an oil spill die unless there is human intervention.
Marine mammals exposed to oil spills are affected in similar ways as seabirds. Oil coats the fur of sea otters and seals, reducing its insulation abilities and leading to body temperature fluctuations and hypothermia. Ingestion of the oil causes dehydration and impaired digestions.
A sheen is usually dispersed (but not cleaned up) with detergents which makes oil settle to the bottom. Oils that are denser than water can be more difficult to clean as they make the seabed toxic.
There are many ways to stop the spread of oil in the ocean. Workers can place a boom around the tanker that is spilling oil. Booms collect the oil off the water. A boom may be placed around a habitat with many animals living there. These booms will absorb any oil that flows around it.
The workers also use skimmers. Skimmers are boats that can remove the oil off the water. Sorbents are sponges that can collect the oil. An airplane can fly over the water dropping chemicals into the ocean. The chemicals can break down the oil into the ocean.
They also can burn freshly spilled oil with fireproof booms to contain the oil. Workers might not decide to burn the oil because this method causes air pollution.
There are just a few ways to clean the oil off the beaches. Workers can use high or low pressure hoses to spray the oil that is on the beaches. Vacuum trucks may be driven on the beaches to vacuum up the oil. They can also simply use shovels or road equipment to collect all the oil off the beaches.
The method used to clean the beaches or oceans depends on many things: the weather, the type and amount of oil spilled, population of that area, types of animals live in that area, and many more things.
All operations should properly examine the risk, size, nature and potential consequences of oil spills and develop appropriate contingency plans, including informing the community of any hazards involved. Contingency planning should facilitate the rapid mobilization and effective use of manpower and equipment necessary to carry out and support emergency response operations.