You are here:
ESTABLISHING MINIMUM FLOWS AND LEVELS OF FRESHWATER IN THE CALOOSAHATCHEE RIVER, FLORIDA, USING RESPONSES OF OYSTERS.
Volety, A. K., S. G. Tolley, AND J T. Winstead. ESTABLISHING MINIMUM FLOWS AND LEVELS OF FRESHWATER IN THE CALOOSAHATCHEE RIVER, FLORIDA, USING RESPONSES OF OYSTERS. Presented at 95th Annual Meeting of the Nat'l Shellfisheries Association, New Orleans, LA, Apr 13-17, 2003.
Alterations in freshwater inflow resulting from watershed development and water management practices have impacted salinity and water quality and led to declines in oyster populations within southwest Florida estuaries. In the Caloosahatchee Estuary, Florida watershed management is typified by large freshwater releases during wet summer months and little or no releases during dry winter months. Effects of watershed management on oysters were investigated to provide guidelines for establishing minimum flows and levels of freshwater in the Caloosahatchee Estuary. Reproductive patterns, Perkinsus marinus disease, spat recruitment, and juvenile oyster growth were investigated. Oysters in the Caloosahatchee Estuary spawn continuously from April-October. Upstream, sub-tidal locations exhibited good spat recruitment, low disease intensity, and higher juvenile growth rates compared to downstream, intertidal sites. High freshwater flows during summer flush out oyster larvae and spat from areas with suitable cultch and/reduce salinities to unfavorable levels for spat settlement and survival. Limited freshwater releases during winter coupled with decreased releases in summer will result in suitable conditions for survival and enhancement of oyster reefs. Water quality targets that should sustain, enhance and restore oyster reefs have been both identified and communicated to water resource managers.