Potential Effects of Hydrologic Loading on Nutrient Content, Microbial Activity, and Other Ecological Parameters in Northeast Shark River Slough (NESS) of Everglades National Park (ENP).

The construction of US highway 41 (Tamiami Trail) to connect the east and west coasts of Florida resulted in a significant ecological and hydrologic barrier between the northern and southern Everglades, separating the modern day Water Conservation Areas (WCAs) from Everglades National Park (ENP). Recently the Tamiami Trail bridge was constructed to allow additional water deliveries to ENP in an effort to restore ecological balance especially by restoring “historic” flows. One concern with increased flows is the potential to increase the phosphorus load to the Northeast Shark River Slough (NESS). Concerns are based on the ecological effects of increased nutrients, especially P, have had in other parts of the system. Previous work has shown that areas around culverts entering into ENP had P-enriched soils, increased biomass of woody vegetation, and other signs of “more eutrophied” conditions. This research study evaluates the changes in nutrient availability on ecological processes and specifically on the functioning of the soil microbial population and the emission of Greenhouse Gases (GHG) as a byproduct of organic matter decomposition. Soil and flocculent detrital organic matter (floc) samples were collected with distance downstream (e.g. 10, 100, 200, 250, 750 m) from inflows in areas directly affected by the bridge and other near canal sites not currently in the bridge flow. Those samples were analyzed for total P, TC, TN and other physiochemical parameters. Preliminary results indicate that the respiration of organic matter by the microbial population at most of the NESS sites are not P-limited but may be limited by the availability of labile C.