Our research traced and quantified indicators of nutrient and microbe inputs to the Grand Bay system through time. We combined data from sediment and water samples, oysters, environmental attributes, and land-use models. We also collected data at three local wastewater treatment plants to determine if nutrients and microbes from these facilities could be traced in the Grand Bay system.
Our analyses covered time periods from up to 3000 years before present (representing pre-urbanization endpoints) to 2020 (for projected land use) for four subwatersheds (Bangs Lake, Bayou Cumbest, Bayou Heron, and Bayou Chico, which are affected by a range of human activities and land use) and their receiving waters.
Changes in land use and associated increases in wastewater and stormwater have altered water quality and the ability to harvest shellfish in the Grand Bay system. We were able to relate land-use changes to historical ecological change and make predictions for the future.