Maury Estes (USRA)

Alabama coastal systems are subject to increasing pressure from a variety of influences including urban development and climate change. Land cover/land use (LCLU) and climate changes have a direct effect on the discharge of rivers that drain into Mobile Bay and adjacent coastal water bodies. The changes in streamflow affect water quality (temperature, salinity, and sediment concentrations) in the shallow aquatic areas and ecosystem functioning. Mobile Bay is a vital ecosystem that provides habitat for many species of fauna and flora. Historically, submerged aquatic vegetation (SAV) and seagrasses were found in this area of the northern Gulf of Mexico; however the extent of vegetation has significantly decreased over the last 60 years. The objectives of this research funded by the NASA Applied Sciences Program are to determine to what extent: (1) LCLU and climate changes affect runoff and water quality in the estuary, (2) how these changes will affect habitat suitability for SAV and seagrasses; and (3) how to best transition these data to benefit coastal policy and decision making. Our approach is to use watershed and hydrodynamic modelling to evaluate the impact of LCLU and climate change on shallow water aquatic ecosystems in Mobile Bay and adjacent areas of coastal Alabama. Under previous work, we had used remotely sensed Landsat data for current LCLU model input and the Prescott Spatial Growth Model to generate future scenarios. Under current work we are using data from the Intergovernmental Panel on Climate Change (IPCC) on future temperature, precipitation, and sea level rise to create climate modelling scenarios. Model outputs will be used to assess the impact on submerged aquatics and other species. The Mobile Bay National Estuary Program organized a Gulf coast stakeholder group to provide feedback to scientists on local conditions and policy concerns and to guide modelling assumptions and the transfer of data and results to coastal resource managers through NOAA EcoWatch and the Gulf of Mexico Atlas.