Summary:
The goal of this proposal is to continue the Louisiana State Universlity (LSU) research projects funded by the Northern Gulf Institute (NGI) that focus on the coastal environments of Louisiana. These projects began as the Shell/LSU Breton Sound Ecosystem Project, which was designed to study two different hydrologic basins including Breton Sound (impacted by the Caernarvon Diversion) and Barataria Bay (impacted by the Davis Pond Diversion).
A coordinated modeling and field observation system has examined how system pulses (freshwater input, storm surge, sea level) drive the geophysical and geomorphic processes that control ecosystem response in biogeochemistry (e.g. nutrient sinks) and energy flow (e.g. higher trophic levels) patterns. Monthly transects at 37 stations in Barataria Basin were conducted to measure NO3, NH4, PO4, and SiO2, Chl a, HPLC, phytoplankton composition, TOC, and TSS. Monthly transcets at 16 stations in Breton Sound were conducted to measure fluorescence, turbidity, salinity, temperture, and light transmittance, NO3, NH4, PO4, and SiO2, Chl a, and TSS.
The combination of transect data with wetland platforms, remote sensing, numerical modeling, and physical measurements of tidal flux through the passes has provided LSU researchers with an intimate knowledge of the coastal environments. The suite of existing LSU NGI projects has laid the ground work for the success of this proposal. The proposed project will take into consideration the presence and impact of oil from the Deepwater Horizon incident. For those areas not yet affected by oil, baseline data specific to the impending impact of the oil will be collected. For regions that have already been impacted the effect of oil on the ecosystem will be investigated.
There are 7 research components to the proposal which will specifically address the following issues:
1. Assess if oil significantly affects water quality by measuring dissolved nutrients, phytoplankton and oil in monthly samples from Barataria and Lake Pontchartrain estuaries and comparing the data to the 10+ year long-term record
2. Measure nutrient dynamics and primary productivity in Breton Sound Estuary as impacted by the Gulf of Mexico oil spill
3. Continue to collect sampels at six stations along each transect to assess the abundance and community composition of phytoplankton, microzooplankton, and mesozooplankton
4. Conduct respiration studies to determine if oil inputs are depressing ecosystem P:R and lowering of estuarine oxygen levels towards hypoxic conditions
5. Examine the phytoplankton response and biological uptake of highly carcinogenic Benzo(a)pyrene at the base of the marine food web
6. Determine the impact of the Deepwater Horizon oil spill on the abundance and virulence of Vibrio in the Gulf
7. Model the effects of pulsed river diversion on oil transport and fish distribution
These projects will significantly contribute to our understanding of the impacts of oil in the Louisiana marshes and estuaries.