An oil spill refers to a form of pollution that involves the discharge of a liquid petroleum hydrocarbon into nature, especially marine environments, because of human activities. In some cases, it is possible for the oil to be spilled in the deep seas. The damage is doubled when the spillage occurs close to the shore since it will affect both the water in the ocean and the habitat along the shoreline. Despite the common association with marine ecosystems, an oil spill can also occur on land. The spillage can arise from several sources including tankers, drilling rigs, offshore platforms, oil wells, and other sources. Oil spills are disastrous for the environment, to the economy, and to society in general.
Effects of Oil Spills
Effect on Water
The most apparent effect of oil spills is the impact they have on the water itself. When the oil is spilled, the water does not mix with oil thus creating a sheen of oil floating on the water. The oils spread fast over a short time to cover vast expanses of the water body. The high speed of the spread of the oil is because of the constant waves, currents, and wind in water bodies. This oil layer, which is known as a slick, is usually thin with a thickness of about 0.01 mm.
Different types of oil have varying reactions when they meet water. For some, they break down quickly while others evaporate slowly and gradually. Regardless of the rate of breakdown, the oil sheen will end up disintegrating and some of the remains will find their way to the ocean floor, especially in shallow waters. Nature has a way to deal with such remains, in the form of microbes, but the damage to the water will remain. Aside from the contaminated water on the surface of the water bodies, ocean floor habitats suffer as well.
Effect on Marine Life
The effects on marine life are far reaching in direct and indirect ways. A marine creature will be affected directly when it ingests contaminated water and may end up dying. If it does not die and a predator far from the spillage eats it, then the contamination chain continues. Another way that marine life is affected is through the destruction of the habitat, which creates a ripple effect in the entire food chain. In addition to death, oil spills threaten the very survival of marine life. For example, fish have reduced reproduction abilities after ingesting too much oil. Marine birds are also affected as oil clings to their feathers thus reducing the ability of the bird to fly and protect itself from the elements.
Effect on the Coastline
The coastline’s damage is closely related to the effect on marine life. Scenes of dead birds and fish coated with oil are common on shorelines located close to oil spillages. This oil also covers the sand and the vegetation thus leading to further effects on the environment. Unless there is an active cleanup of the shoreline, the natural integration of oil is slow, thus increasing the time the environment is exposed to harmful substances.
The World's Worst Oil Spills
The Persian Gulf oil spill, the worst oil spill in history, caused the release of between 5 and 10 million barrels of oil (as much as 300 million gallons) into the Persian Gulf in 1991. The damage was far reaching, spoiling vast tracts of coastal habitat in Kuwait and Saudi Arabia as well as having catastrophic effects on marine populations of several rare and endangered species. The Amoco Cadiz Oil Spill Disaster, the worst oil spill of its time, occured on March 16, 1978. The sinking of the Amoco Cadiz released 69 million gallons of oil into the sea causing the deaths of over 20,000 sea birds as well as countless other fishes, echinoderms, and crustaceans. It was later calculated that the disaster caused an estimated loss of $250 million USD to the fishing and tourism industry.