Life History Study of the Commercial Oyster in the Lower Laguna Madre - Survey of Oyster Populations and Associated Organisms

Population studies of the commercial oyster, Crassostrea virginica, showed little fluctuation in size distribution from February to December, 1962, with the exception of May, when a high percentage of spat were first noticed, indicating a heavy spat set in April. Test oysters survived and showed good growth in brackish waters of the Arroyo Colorado, although a spat set did not occur there. Analysis of the ratio of dry weight to wet weight showed oysters from South Bay, Port Isabel Bay and Arroyo Colorado to be in fairly good condition. Commercial production in South Bay has been very poor since redredging of the Brownsville Ship Channel in January, 1962. This dredging caused siltation, which killed oysters and covered up clutch. A private oyster lease in South Bay, to which shucked shell is being returned, has steady oyster production in 1962.