The study was conducted to measure levels of toxic chemicals and bacteriological indicator organisms in clams taken from recreational harvesting areas of Puget Sound. The overall study hypothesis was that shellfish collected at sites close to urban bays would be found to have higher levels of such contaminants and indicator organisms than those collected at sites well away from urban or industrial influences. The chemicals selected for measurement were based on their toxicity, distribution and persistence in the environment. All were on the EPA's Priority Pollutant List and had been recognized as compounds of concern in Puget Sound. Target species were Protothaca staminea, the native little neck clam and Saxidomus giganteus, the butter clam taken from selected sites around Puget Sound.

"June 1988." "A cooperative study agreement between Office of Puget Sound Water Division, United States Environmental Health Protection Agency, Region 10, Seattle, Washington {and} Shellfish Section, Office of Environmental Health Programs, State of Washington, Department of Social and Health Services, Olympia, Washington. Project officers: John Strong (EPA), Gary Plews (DSHS)." "Prepared in cooperation with United States Environmental Protection Agency, Region 10, Office of Puget Sound, Seattle, Washington."