1998 Year of the Ocean Perspectives on Marine Environmental Quality 



be suspended in the water column, ultimately settling in sediments and concentrating in marine 

 organisms. Discharged garbage'" adversely affects marine life (due to entanglement or ingestion), 

 and can also cause vessel damage through propeller entanglement and by disabling engines when 

 sucked into intake valves. The potential negative consequences of invasions of non-indigenous 

 species are becoming an increasing concern at ports and coastal areas. 



In U.S. coastal and ocean waters, dredged material is the primary waste transported and 

 directly disposed.'"* The U.S. disposes of approximately 300 million cubic yards of dredged 

 material each year from inland and coastal waters, only 60 million cubic yards (20 percent)''' of 

 which are disposed of in open ocean waters. Unregulated and uncontrolled disposal of dredged 

 material can increase suspended solids in the water column and smother benthic organisms. If the 

 sediments are contaminated, there is a potential for acute or chronic toxicity in marine organisms 

 and a risk to human health (U.S. EPA, 1991). 



Indirect Discharges 



One to two-thirds of pollutants contributing to the degradation of coastal and marine 

 waters are from indirect sources, and include sediments, nutrients, pathogens, and toxic 

 compounds. The difficulty in controlling these pollutants is the diverse array of sources (which 

 include runoff and seepage from agricultural and urban areas, and air deposition onto land and 

 into water) and the multiple methods of transport. Nationwide, it has been estimated that indirect 

 loadings account for more than half of the suspended solids, nutrients, fecal coliform, and metals 

 entering coastal waters annually. Runoff from non-urban areas, sewage spills and overflows, 

 urban storm water runoff, and combined sewer overflows are often responsible for seafood 

 advisories and shellfish bed and beach closings. 



Pollutants from agricultural and pasture lands include sediments, fertilizers, pesticides, 

 herbicides, and animal wastes which contain bacteria and nutrients. Eighty-eight percent of the 

 total suspended solids entering marine waters are from agricultural runoff contributing to water 

 quality problems such as light attenuation and the smothering of sensitive ecosystems (U.S. EPA, 

 1995). Excessive nutrients can stimulate the growth of algae and other plants and organisms, 

 which in turn deplete the levels of dissolved oxygen and harm aquatic life; too many nutrients 

 can also trigger toxic algal blooms. Bacteria and pesticides from agricultural and pasture lands 

 can kill aquatic life, contaminate seafood, and necessitate the closing of shellfish beds. Cleared 

 land has a reduced capacity to absorb water, resulting in increased sediment transport, increased 

 flooding, reduced recharging capabilities of local aquifers, and increased quantities of toxic 

 chemicals and nutrients transported to local waterways. 



1 ' The Centers for Disease Control have linked an outbreak of illnesses during the summer of 1997 to waterborne pathogens 

 originating from vessel discharges of sewage in shell fishing areas in the Gulf of Mexico (CDC, 1997). 



12 Garbage includes but is not limited to: glass, metal, paper, plastics, and food wastes. 



13 While several other nations dump industrial wastes and sewage sludge into ocean waters, the U.S. stopped industrial waste 

 dumping in 1988 and ended such sewage sludge disposal practices in 1992. 



'4 It should be noted that an estimated 5-10 percent of all sediments dredged in the United States are not suitable for open water 

 ocean disposal (NRC, 1997). Alternative disposal is sought for these sediments. 



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