Inputs of Mississippi River water change both hydrologic regime and nutrient loading to the Breton Sound and Barataria Bay estuaries.

We hypothesize that this bottom-up forcing changes  structure and function of phytoplankton and microbial communities, creating fast-turnover dynamics under nutrient-rich, fast flow-through systems. River inputs also flush marshes during flood events and likely result in a more complex mixed system in the open waters sampled during transect work. We also hypothesize that the algal groups that will respond to eutrophication will differ between marine and fresh water portions of the estuarine systems. (Table 1)