Influence of Increased Freshwater Inflow on Nitrogen and Phosphorus Budgets in a Dynamic Subtropical Estuary, Barataria Basin, Louisiana

Coastal Louisiana is currently experiencing high rates of wetland loss and large-scale ecosystem restoration being implemented. One the largest most novel projects a controlled sediment diversion, proposed to rebuild sustain wetlands by diverting sediment- nutrient-rich water from Mississippi River. However, impact this diversion on nutrient budget receiving basin largely unknown. A quality model was developed investigate planned Mid-Barataria Sediment Diversion Barataria Basin (herein referred as ‘the Basin’). The results indicate that will increase TN TP pools about 38% 17%, respectively, even with loadings >300%. Water suggest nutrients in be mitigated increased advection transport (i.e., decreased residence time ~170 days ~40 days, leading greater flushing) removal via assimilation, denitrification, settling within Basin. Advection resulted higher than other processes, such uptake or denitrification. Approximately 25% additional loading 30% were processed through assimilation phytoplankton vegetation, burial sediment/soils. These budgets help better understand how project may change future ecological conditions estuaries coastal near-shore northern Gulf Mexico.