1998 Year of the Ocean Perspectives on Marine Environmental Quality 



exists that can support the demands of multiple uses and still provide an aesthetically pleasing 

 environment. 



Pollution Pressures 



Direct Discharges 



Direct discharges are defined here to include releases from vessels, discharges of 

 municipal and industrial wastewater via pipelines, and dumping of waste materials, such as 

 dredged material, into ocean waters. In the United States, there are more than 2,000 sewage 

 treatment plants, municipalities, and industrial facilities discharging effluents into estuarine and 

 coastal waters. Approximately 2.3 trillion gallons of effluent are discharged into marine waters 

 from sewage treatment facilities annually. While most of this sewage meets secondary treatment 

 standards prior to disposal, nutrients and pathogens from such discharges can contribute to the 

 degradation of local marine ecosystems — creating "dead zones"'' and forcing the closure of 

 shellfish beds and swimming areas. Nutrient loading can be significant causes of degradation to 

 coral reefs and other coastal ecosystems. 



More than 2.8 billion gallons of industrial waste water per day^ are discharged directly 

 into U.S. ocean waters (U.S. EPA, 1994). Many of the chemicals discharged into marine waters 

 can be toxic even in minute concentrations, and can compromise the water column, contaminate 

 sediments, and concentrate in marine organisms. Leaching from hazardous waste sites has been 

 the source of many toxins in marine waters (e.g.. In New York, PCBs are leaching into the 

 Hudson River in from an abandoned industrial plant). Exposure to these chemicals and metals 

 can pose risks of acute or chronic^ toxicity to marine organisms. In addition, the risks to 

 predators and humans can be increased if toxins become concentrated through the food chain. In 

 some locations, thermal pollution from electric generating plants has been shown to stress marine 

 organisms by raising the ambient temperature of the water. 



During operations, vessels may be responsible for directly discharging oil, sewage, 

 garbage, and non-indigenous species into marine waters. Some pollutants are from direct 

 discharges (e.g., the emptying of sewage from vessel toilets, or ballast water exchange), while 

 others may be a result of leaching (e.g., anti-fouling agents or paints).'' Once discharged, 

 pathogens in sewage can impact drinking water intakes (e.g., in the Great Lakes), and necessitate 

 the closing of shell fishing and swimming areas; discharged nutrients, meanwhile, can increase 

 eutrophication.'°" Oil and other chemical contaminants washed or discharged into the ocean may 



6 Dead zones are areas within a water body where the oxygen level in the water is so low that plants, t'lsh. and other marine 



organisms are unable to survive. 



^ This estimate excludes electric utilities and offshore oil and gas effluents. 



8 Acute levels of toxins are defined as lethal, while chronic levels are sublethal and result in disease or disruptions to 

 physiological or reproductive processes. 



9 According to 1991 customs data, ballast water exchanges from foreign vessels exceeds 58 million gallons per day (Shipping 

 Study. 1995). 



'0 Eutrophication is the increase in biological productivity of an aquatic system as a result of natural or artificial inputs of 

 nutrients. 



E-7 



