The Effects of Oil Spills on Marine Life

Oil spills occur when incidents involving oil tankers, barges or other vessels cause them to spill oil into rivers, bays and oceans. These incidents could be the result of the breakdown of machinery, human error, or even intentional acts of malice. No matter how an oil spill occurs, the effects are usually devastating for the environment and marine life.

Marine Mammals

• Seals ingest oil while feeding in areas where a spill occurred.

  Marine mammals include sea lions, sea otters, seals, dolphins, seals, sea cows, walruses, whales and porpoises. Most are dependent on air and frequently feed near the surface of the water. Their habits increase the possibility of them coming into contact with oil spills, which causes numerous toxicological effects. Some of these effects include secondary organ dysfunction, which occurs as a result of the ingestion of oil while feeding in areas that have been polluted by oil spills; damaged airways, gastrointestinal ulceration and hemorrhaging, which are a result of ingesting oil while grooming and feeding; and congested lungs and hypothermia due to changes in the skin that may have been coated with oil. Other effects are restricted diet, which may result in a decreased body mass or starvation; skin and eye lesions as a result of continuous oil exposure; and behavioral changes caused by the stress of prolonged oil exposure.

Sea Birds

• Sea birds can't fly when their feathers are coated with oil.

  Sea birds are sensitive to the effects of crude oil and its refined products. They can be affected by oil spills because of the amount of time they spend on or near the surface of water and affected shores. They are most vulnerable when feeding since some species of fish are able to survive under floating oil and birds come into contact with oil while diving for the fish. Their feathers can become coated with oil, which causes a matting of the feathers. This matting hampers birds' ability to fly and causes a breakdown in the water proofing and thermal insulation provided by the feathers, resulting in hypothermia. Oil-slicked feathers are also heavy, which can lead to drowning since they can neither fly nor remain buoyant on the surface of the water. The sea birds also tend to ingest the oil with their food and also while preening themselves in an attempt to get rid of the oil. This leads to intestinal damage, reduced reproductive abilities, adrenal damage and alterations of liver metabolism.

Sea Turtles

• Oil affects the mucous membranes of sea turtles.

  Sea turtles are affected by oil spills when they surface in an oil slick to breathe. The oil causes irritation in mucous membranes such as the throat, eyes and nose, which leads to inflammation and infection. Their food supply might also be contaminated by the oil spill, causing damage to their digestive tracts and other organs.