Coastal wetlands of the northern Gulf of Mexico provide numerous ecosystem services, including regulating pollutants and runoff, providing habitat for ecologically and economically important species, and regulating greenhouse gas emissions (CO2, CH4, N2O). Impacts from the Deepwater Horizon oil spill and subsequent use of dispersant may alter these ecosystem functions through their effects on key aspects of wetland carbon and nitrogen cycling, including nitrification-denitrification pathways, above- and belowground plant productivity, and ecosystem-level physiology.
Our goal is to provide a comprehensive, multi-scale approach to understand the oil/dispersant impacts on vegetated coastal marshes along an oil-exposure gradient from western Mississippi to Alabama at the Grand Bay National Estuarine Research Reserve (NERR), MS (highest exposure), Point Aux Pines, AL (intermediate exposure), and Dauphin Island, AL (lowest exposure). To that end, we will quantify net ecosystem exchange (NEE), ecosystem respiration (Reco), Normalized Difference Vegetation Index (NDVI), aboveground production, fine root production, and coupled nitrification-denitrification within Juncus roemerianus-dominated and Spartina alterniflora-dominated stands at each marsh. Measurement of these variables will allow us to assess species-specific responses to oil/dispersant pollution along the Mississippi-Alabama Gulf Coast.