Mercury Concentrations and Isotope Values in Sediment, Fish Tissue, and Water from the Mobile River, 2023-2025

This dataset details concentration and stable isotope ratio measurements for mercury across sediments, water, and biological tissue (Lepomis macrochirus, Bluegill and Micropterus salmoides, Largemouth bass) collected from the Mobile River in Alabama between 2023 and 2025. In 2025, sediment collections from the Stauffer Cold Creek Plant and Lemoyne Plant Superfund Sites in Axis and Bucks, Alabama and adjacent Mobile River sites were performed by the U.S. Environmental Protection Agency and the U.S. Army Corp of Engineers to assess mercury sources to the region. Biological tissue and water collections were conducted by the U.S. Geological Survey and U.S. Fish and Wildlife Service in conjunction with the Alabama Department of Environmental Management in 2023 across four sites within the Mobile River to assess changes in mercury sources during high water levels. The data demonstrate a broad range of mercury concentration and isotope values that will aid data-driven management decisions in the Mobile River Basin.