GROUND WATER/SWACE WATER INTERACTIONS

Florida state law mandates that water use is regulated through a permitting pro- cess which requires the protection of wetlands greater than 0.20 ha. The wetlands' permitting criteria is being scrutinized for effectiveness in protecting wetland functions. Hydrologic alter- ation can adversely impact wetland ecosystems. Detecting an ecological response to hydrologic alterations, especially resulting from groundwater withdrawals, can be subtle and difficult to quantify. To test wetland protection criteria, a hydrologically sensitive indicator species was needed. Native crayfish species, trophically critical elements of Florida wetlands, were selected. Mesocosm studies are being performed to ascertain the survival threshold of crayfishes to hydroperiod alterations. This index will be applied within the permitting process to modeled water usage to determine if the requested water allocation will cause impacts that could nega- tively affect wetland function. KEY TERMS indicator species, crustaceans, ecological assessment, groundwater, wetlands.