Cooperative Fish and Wildlife Research Units Program: Virginia
Education, Research and Technical Assistance for Managing Our Natural Resources

PROJECT DESCRIPTION: This project is a piece of a larger USGS poject to provide a basic foundation of hydrologic, biological, and geographic data collection, summary, and evaluation on the Clinch River to support process-level studies of ecosystem response to stress in response to changes in land use, energy extraction practices and climate. The USGS water science centers in TN and VA are currently monitoring water quality and geomorphology within the basin, while the Missouri and Virginia Coop Units are doing toxicology studies and population studies respectively. OBJECTIVES: River discharge, water quality, sediment quality, and juvenile mussel survival will be evaluated over a period of three years at two primary monitoring sites and at ~8 other locations. PROGRESS: Over the first 2 years of this 3-year study, we have collected discharge, water quality, sediment quality, and habitat quality information. We have also documented mollusk assemblages and conducted in situ mussel juvenile growth and survival studies at sites upstream, within, and downstream of the impacted reach. We documented a gradient of increasing mollusk density and richness from upstream impacted reaches in Virginia to presumably healthy reaches downstream in Tennessee. Growth and survival of in situ juveniles have not reflected this gradient and may be influenced by local drivers. We have collected paired discrete water quality samples (nutrients, metals, major ions, suspended sediment) at one impaired site and one downstream healthy site during both base-flow and storm events. We have also sampled polycyclic aromatic hydrocarbons (PAHs) during storm events. Differences in major ion chemistry at base-flow and metals concentrations during storm events might provide some insights that help explain the mollusk assemblage gradient. Additionally, continuous monitoring has detected higher specific conductance and turbidity in the impacted reach than in the healthy reach. Preliminary results of this study are being used to refine hypotheses and more effectively direct investigations in the Clinch River.