Reports on studies of spawning and larval rearing of Manila littleneck clams, native littleneck clams, butter clams and gaper clams, including field work. "Field studies comparing growth and survival of laboratory-reared and imported Pacific and Kumamoto oysters were completed. We continued studies comparing various methods of oyster culture in Yaquina Bay. Winter survival of laboratory-reared oyster spat was determined. Adult red abalone were obtained for spawning purposes." (p.1)Covers July 1, 1970 to June 30, 1971.