Recently, there have been several incidents of high morbidity and mortality among various species of marine mammals and endangered species. There is concern that pollution of the marine environment may have played a major or contributing role in some of these disease processes. The marine waters of the United States estuaries, coastal waters and the open ocean are used extensively for the disposal of various types of wastes. Toxic chemicals, metals, pathogens and nutrients enter the marine environment from ocean dumping, discharge pipes, and nonpoint sources. Many of these compounds are known to cause detrimental effects both to aquatic animals, plants and water quality.

The health of endangered species may be impacted from pollutants via a number of different mechanisms. Extremely toxic or high concentrations of chemicals may cause direct systemic toxicity. Pathogens infective to enter the oceans through sewage discharge and agricultural runoff. Chemicals may indirectly affect animals through low level chronic exposure or effects of complex mixtures. Damage to critical physiological functions such as the immune or reproductive system may kill individuals or cause populations to decline. Pollutants may also cause change to environmental quality that could alter critical habitats or limit food resources.