The Effects of Oil Spills on Marine Organisms

Oil spills have devastating effect on marine organism and habitats. Juvenile fish, amphibians and mollusks are most sensitive to pollution because their immune systems are not fully developed and they are most dependent on regular feedings while experiencing rapid growth. Marine mammals and birds often have better chances for survival after an oil spill, due to their limited ability to relocate to other areas.

Disruption of Bodily Functions

• Several compounds derived from oil have been shown adverse effects on marine organisms. Many of these compounds will cause immediate death, especially to larvae and juveniles, or prevent feeding. Once oil has covered the surface of water, it blocks the interface between the atmosphere and the water, preventing the exchange of gases, such as oxygen and nitrogen. Pollution caused by oil spills will also adversely affect behavior, immune function, hormone synthesis and reproductive abilities, thereby endangering entire populations of marine organisms.

Effects of Oil on Larvae

• Fish that develop on the surface of marine waters are especially susceptible to oil spills. A study published in the February 2011 issue of the "Marine Pollution Bulletin" investigated the effects of oil spills on the larvae of the Japanese flounder. The authors noted that a protein, named Sema3, which controls the growth of nerve tissues, was overexpressed in flounder larvae exposed to concentrations of more than 8.75 mg of oil per L of seawater. The researchers found that the nerve tissues in the exposed fish were growing in abnormal locations.

DNA Damage

• Polycyclic aromatic hydrocarbons are constituents of petroleum and have been previously shown to induce damage to DNA. A study appearing in the September 2002 issue of "Marine and Environmental Research" investigated the effects of PAHs on bivalves, including clams and mussels. The researchers found that petroleum spills had little effect on clams but noted that DNA damage occurred in the digestive glands of mussels.

Contamination of Food Sources

• Mangroves create a habitat along coastlines that are important breeding locations and food sources for marine organisms. An article included in the February 1996 issue of the "Bulletin of Environmental Contamination and Toxicology" reported the effects of oil spills on mangrove habitats. The authors stated that once an oil spill occurs, remnants of petroleum pollution will remain in mangroves because of reduced sediment transport and the lack of aerobic bacteria to degrade the hydrocarbons. The study focused on naphthalene, a toxic constituent, and its ability to alter behavior in gastropods, the class of mollusks including snails.