Florida Lake Management Society Annual Conference, Naples, Florida, June 4 – 7, 2007
MEASURING SEDIMENT NUTRIENT FLUXES AND SEDIMENT OXYGEN DEMAND IN LAKE JESUP
Scott A Lowe Manhattan College HDR|LMS Engineers Gloria Eby Seminole County, FL
As part of the ongoing effort to understand the eutrophication processes at work in Lake Jesup, two field efforts were mobilized. The first involved the measurement of sediment nutrient fluxes and sediment oxygen demand. The second involved the measurement of nitrogen fixation by algae. The results indicated that the internal sources of nutrients in Lake Jesup via these two mechanisms are significant. Sediment fluxes contribute an estimated 1573 MT/yr of TN and 739 MT/yr of TP. Nitrogen fixation adds another 357 MT/yr of TN. By comparison, external loads of TN and TP are estimated to contribute 220 MT/yr and 27 MT/yr respectively. In percentage terms 90% of the nitrogen load and 96% of the phosphorus load is generated internally. This presentation will discuss the field data collection efforts, results and implications. Sediment oxygen demand was also large, averaging almost 2 g O2/m2/d.
Session 5A – Page 6