Sediment-Associated Pollutants and Water Quality in St. Louis Bay, Mississippi

Objectives Our objectives are to: a) determine metal and toxic organic compound concentrations in sediments, water, and certain organisms in St. Louis Bay, MS, b) use radiochemical measurements to provide inventories and histories of metals and toxic organic compounds in St. Louis Bay, c) use chemical fingerprinting to track the sources of metals and toxic organic compounds in St. Louis Bay, d) develop a fact sheet and web site for publicly communicating our findings, and e) report our results to state and local agencies as well as in the peer]reviewed scientific literature. During this 4]year project, we will examine metals and organic contaminants in various phases in St. Louis Bay, including sediments, shellfish, suspended particulate matter, and water. This research requires quantification of multiple parameters including: trace metal geochemistry (water column and sediment]associated), dioxins/furans and coplanar PCBs, sedimentology (grain size distributions, particulate organic carbon) and radiochemistry (fallout isotopes including 7Be, 137Cs and 210Pb). The combination of these methods will allow for a comprehensive characterization of metal and organic contaminant loadings to sediments, sedimentary and water column inventories, time frame of deposition, and the depth and extent of Hurricane Katrina driven sediment mixing. Contributions Contributions will be made in a number of areas, including: (1) The Yeager group will participate in the planning of remaining field work, particularly those that involve the collection of sediment cores for the purposes of sedimentological and radiochemical characterization. (2) Yeager will supervise all sedimentological and radiochemical elements of the project, including coordinating sample collections, analytical work and the contributions to the larger research data base. Cores will be described for a range of physical properties, including porosity, bulk density, sediment texture and POC concentrations. We will use a suite of radionuclides (7Be, 137Cs, 210Pb) to quantitatively determine depths of sediment mixing, and sediment geochronology, from which sediment accumulation rates can be derived. (3) The Yeager group will fully participate in the dissemination of research results, including the development of fact sheets, providing materials for a project website, presenting research results at professional meetings and the development of peerreviewed publications. *The Yeager research group will be working with USM collaborators during the entire remaining term of the project, despite this subcontract being in place over only one year.