To assess historical environment changes associated with changes in hydrologic connection to the Gulf Intracoastal Waterway (GIW) and Mobile Bay, six sediment cores (50-80 cm in length) were collected in 2021 from two coastal wetland sites. These two sites in Gulf Shores, Alabama were: Oyster Bay Nature Preserve ("OB", a brackish marsh with natural hydrology) and the Emmet O. and Vina Wenzel Wetland Preserve ("WW", an impounded coastal wetland). The OB control site is a 1.5 square kilometer wetland with ...