Oyster mortality study : summary report, 1966-72 Public Deposited
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"We monitored oyster mortality in Yaquina, Coos, and Tillamook bays from July 1966-March 1972. Pacific oyster (Crassostrea gigas) mortality in Yaquina Bay appears to be lower than in any other reporting area on the Pacific Coast, generally less than 2% per year. Native oyster (Ostrea lurida) mortality ranged from 9.6-28.2%. Low salinity stress caused over one-half of this mortality each winter. In Tillamook Bay, Pacific oyster mortality generally averaged 4% per year; mortality in Coos Bay averaged 7% a year, excluding an unexplainable mortality of 19% during the summer of 1968. Bay mussel mortality totaled 49.9% in 1970-71 and 19.3% during 1971-72. Predation by small crabs probably caused these high mortalities..." (from the Abstract) Other work included a study of oyster shell growth, histological examinations of oyster tissues, a study of changes in the hydrography of Yaquina Bay, a study of a "neoplasm disease" of oysters in Yaquina Bay, a study of the sensitivity of native Olympia oysters to reduced salinity, and a study of molluscan sensitivity to outboard motor effluent.