A two-year study in San Diego Bay reveals that vessel waste discharges produce undesirable water quality conditions in areas of concentrated vessel activity. The study examined the effects of waste discharges representative of up to one-fourth of the U.S. Navy's entire active fleet, more than twenty-five hundred pleasure craft containing sanitary facilities, over a hundred ships of the West Coast commercail fishing fleet, and commercial freight vessels carrying in excess of a million tons of cargo to the Port of San Diego each year. Wastes discharged from these vessels were found to create conditions that are hazardous to health, aesthetically offensive and damaging to ecological balances in San Diego Bay. (Author)