USGS science is helping to guide coastal estuary restoration decisions in the northern Gulf of America
Two new studies led by Dr. Davina Passeri and Rob Jenkins show the impacts of proposed interior headland restoration on hydrodynamics, salinity and sediment transport in Grand Bay, Alabama.
Coastal estuaries are economically and ecologically significant environments that provide a range of services to ecosystems and human communities. Located in the northern Gulf of America, Grand Bay is an open coast estuary at the border of Mississippi and Alabama that is experiencing high rates of shoreline erosion as a result of storms and sea level rise (SLR). Coastal managers are exploring restoration options to increase estuarine resilience including reconstructing the degraded interior headlands using dredged sediments. Two companion studies led by Dr. Davina Passeri, Rob Jenkins and colleagues provide important information on the potential impacts of proposed interior headland restoration on tidal hydrodynamics, salinity, and sediment transport under present-day conditions and future SLR. The authors found that the restored headlands sheltered the marsh shorelines from waves, and there were small, localized changes in tidal currents, average salinity concentrations and bed morphology in the vicinity of the headlands. However, regardless of the proposed restoration actions, the greatest sediment fluxes remained directed out of the estuary (exporting sediment), which was shown to increase by 30% under 0.5 m of SLR.
This study was funded in part by The Gulf Coast Ecosystem Restoration Council (RESTORE), NOAA’s National Centers for Coastal Ocean Science Competitive Research Program and the USGS Coastal & Marine Hazards in Resources Program. It was done in collaboration with Alabama Department of Conservation and Natural Resources and Volkert, Inc.