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USING RESPONSES OF OYSTERS IN ESTABLISHING MINIMUM FLOWS AND LEVELS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA
Citation:
USING RESPONSES OF OYSTERS IN ESTABLISHING MINIMUM FLOWS AND LEVELS IN THE CALOOSAHATCHEE ESTUARY, FLORIDA. Presented at 6th Internat'l Conference on Shellfish Restoration, Charleston, SC, Nov 20-24, 2002.
Description:
Volety, Aswani K., S. Gregory Tolley and James T. Winstead. 2002. Using Responses of Oysters in Establishing Minimum Flows and Levels in the Caloosahatchee Estuary, Florida (Abstract). Presented at the 6th International Conference on Shellfish Restoration, 20-24 November 2002, Charleston, SC. 1 p. (ERL,GB R959).
Disease prevalence and intensity of Perkinsus marinus, gonadal index, spat recruitment, and growth rate of juveniles were investigated in the Caloosahatchee Estuary, FL, in relation to season and freshwater releases from Lake Okeechobee during September 2000 - July 2002. Dry winter months in year 1 had little or no freshwater releases (<300 cubic feet per second; CFS) while year 2 had >300 CFS. Freshwater releases during dry months (Nov - May) in year 2 resulted in lower salinities and lower infection intensities at all locations compared to year 1. Prevalence of P. marinus ranged from 0 - 90% while the intensity of infection ranged from 0 - 2.5 (on a scale of 0 - 5). Analyses of observed salinities and freshwater flows suggest that freshwater releases of 1000 CFS decrease salinities by 3.6 - 6 ppt at the sampling locations (downstream - upstream locations). Salinity and temperature during the study period ranged from 3 - 40 ppt, and from 16 - 32?C respectively. While the disease prevalence was high, overall infection intensities at various sampling locations were light (0.170 - 0.753) during both years suggesting that freshwater releases less than 300 CFS did not result in lethal (heavy) infection intensities. Flows between 500 and 2000 CFS will result in optimum salinities for oysters and will result in sustaining and enhancing oyster populations in the Caloosahatchee Estuary. Results suggest that well-timed freshwater releases into Caloosahatchee River may lower P. marinus infections to non-lethal (light) in oysters and enable them to survive longer.