Overnight Shark River Surveys from Shark River Slough, Everglades National Park (FCE), South Florida from October 2001 to March 2002

Estuarine mixing interfaces have been a focus of wetland ecologists for the last three decades and are of growing concern today. Particularly critical in Everglades restoration, water quality and the dynamics of nutrients and dissolved materials across seasons in the natural system are being defined. We measured diurnal and seasonal (wet and dry) variation in microbial, dissolved and total nutrients and total organic carbon along a riverine transect and for a diurnal cycle in October of 2001 and March of 2002. For the diurnal sampling we anchored a houseboat mid Shark River 100m up river of the mesohaline Florida Coastal Everglades Shark River LTER site and sampled the water for chemical, microbial, and physical parameters. At slack high and low tides we sampled 10 miles offshore then at three sites up the Shark River. TOC (mM) and salinity (ppt) were highly correlated (r2 .97) along the river transect across seasons and TOC derived from terrestrial input. Bacterial production ranged from 1.88 to 10.99 mg C l-1 d-1 and was greatest in the dry season and at the most freshwater sampling points. Combined examination of our 49 sampled parameters both from the diurnal sampling and river transect sampling showed that our position for sampling in the river was critical and that the mid river-estuarine productivity maxima occurred within Shark River in both the wet and dry season. These data suggest this oligotrophic estuarine-river system is highly sensitive to watershed and river fringe nutrient inputs and remineralization vectors within the river.