The Sarasota Bay Estuary Program was recently awarded a second Environmental Protection Agency (EPA) Region 4 Wetland Program Development Grant to continue their work on southwest Florida tidal creeks. Dr. Jay Leverone, SBEP staff scientist, will be leading this collaborative effort, which includes both Tampa Bay and Charlotte Harbor Estuary Programs as well as staff from six coastal counties.
In our first study, we observed that organic nitrogen was higher than expected - from freshwater dilution - in the lower reaches of many creeks that had mangrove fringes and emergent vegetation. This led us to ask whether these nutrient inputs were natural or anthropogenic. Tidal creek wetlands provide several useful ecosystem functions: they trap and filter particulate organic matter, provide a substrate for remineralization by enhancing the microbial loop, and modulate the export of biologically available nutrients. When functioning properly, these processes provide efficient trophic transfer to the estuary. Inputs of anthropogenic nutrients in other forms or at excessive concentrations can overwhelm and disrupt these functions.
In this study, we will be working on the premise that the ratios of nutrients in the water and sediment can serve as indicators of tidal creek condition. Our findings will be incorporated into regional nutrient management frameworks for the protection and restoration of our local tidal creeks. We hope to determine if these creeks are operating within their capacity to process nutrients, which would then help us develop specific water quality indicators for their protection. We will also suggest ways to reduce the potential for adverse effects of anthropogenic nutrient inputs as well as identify effective restoration strategies to repair damaged systems.