U.S. Fish and Wildlife Service Grant for Investigating Water Quality Threats

This is a Notice of Intent to Award a Grant Agreement between the U.S. Fish and Wildlife Service and Virginia Polytechnic Institute and State University (Virginia Tech) for the purpose of investigating water quality threats in the Upper Tennessee River system, specifically in the Clinch (CR) and North Fork Holston (NFHR) rivers in Virginia and Tennessee. These rivers support 18 federally listed and 4 candidate freshwater mussel species. The research will assess the effects of various contaminants on the health and reproduction of adult mussels. The results of this research will guide management actions related to conservation of freshwater mussels and their habitats in these key rivers, and will have wider application to other river systems throughout the eastern United States. The research plan specifically identifies personnel at Virginia Tech to implement the investigation, as they are uniquely qualified to accomplish research tasks involving mussel histology, contaminants assessment and have decades of experience and knowledge of the CR and NFHR mussel fauna assemblages.
The research will assess the health of adult freshwater mussels by quantitatively evaluating vital organ tissues, including digestive glands, gills, kidneys, and gonads. There will be 2 research components. During the first component, organ tissues of caged adult mussels held at sites in the zones of population increase and decrease in the CR will be evaluated and statistically compared. Quantitative histological results will be statistically correlated with water quality results from ongoing research projects in the CR. In the second research component, adult mussels will be exposed to high-low concentration mixtures of Na+, K+, Ca2+, Cl-. Also, unionized ammonia exposures will be conducted using the highest levels measured at ongoing investigated CR sites and seepage points at the Saltville chemical holding ponds in the NFHR. After 3 mo exposures, organ tissues of mussels from exposures and controls will be evaluated and statistically compared. Histological evaluations of vital organ tissues from adult mussels will provide data to assess the effects of environmentally relevant concentrations of ions and unionized ammonia. Specific objectives of this research are: (1) to assess health of adult rainbow mussels, Villosa iris, caged at four sites each in the 2 zones (population increase and decrease zones) in the CR using histological evaluations of vital organ tissues, including gill, digestive gland, kidney, and gonad; (2) to correlate quantitative data generated during Objective One with water quality data collected during ongoing investigations at the same CR sites; (3) to rank surveyed CR sites based on the results of Objective One for determination of site management priorities; (4) to assess health of adult V. iris exposed to high-low combinations of concentration mixtures of Na+, K+, Ca2+, Cl- using histological evaluations of vital organ tissues, including gills, digestive glands, kidneys, and gonads; and (5) to assess health of adult V. iris exposed to environmentally relevant concentrations of unionized ammonia measured in the CR and NFHR using histological evaluations of vital organ tissues, including gills, digestive glands, kidneys, and gonads. These project objectives would begin the process of evaluating CR sites based on the health of non-listed mussel species, and allow for inferences on the physical condition of threatened and endangered mussel species at the same sites of occurrence. By ranking sites using health of mussels, management priorities and strategies could be better guided at key sites in the CR. Program results also could provide the critical biological data needed to determine the effectiveness of management strategies, and act as a warning system to detect imminent population declines. Results from evaluations of mussel health at key sites on the CR will aide in the accomplishment of outcome-based monitoring within the Strategic Habitat Conservation (SHC) framework. The results also could serve as baseline data for future site assessment within the SHC context.