Geospatial assessment of threats to freshwater mussel populations within the Upper Duck River watershed

Tyler N Skelton, Tennessee State University


Conservation of biodiversity is critical in maintaining healthy ecosystems. The Duck River of Tennessee is considered one of the most biologically diverse freshwater systems in North America. Mussel populations are particularly sensitive to pollution and are key indicators of water quality. A geospatial information system (GIS) was developed to identify the spatial location of stressors and the magnitude of stress in relation to mussels and mussel host fish occurrences. Threats assessed included non point source pollution from agriculture, point source pollution from Water Pollution Control (WPC) permits, and dams and their potential for mussel/host fish fragmentation and downstream effect on mussel populations. An assessment of population distribution of individual mussel species and their host fish identified the relationship between threat and mussel shoals. Stream reaches containing mussel and associated host fish habitat overlap were identified as productive reproduction sites, and mussel habitat lacking host fish overlap were located and prioritized as in need of field sampling to ensure the availability for population growth. The majority of mussel occurrences (12 to 440 observations per catchment) were found within eight catchments along 43 km of 139.7 km of the Upper Duck River. These eight catchments were consistently identified by the GIS as areas of medium to low threat risk regions, suggesting that the mussel communities were thriving in a clustered area with minimal threats. The small area, however, suggested that species richness and abundance may be low throughout the rest of the watershed. Mussel observation densities and species diversity were greatest within 0 to 15 km downstream of Lillard's Mill Dam, while high observation densities and species diversity were not present until 100 km downstream of Normandy Dam, suggesting that the difference in type and operational characteristics of each dam had a vastly different effect on mussel populations downstream. The GIS developed in this project will be applied in the decision making process to identify threatened river reaches, and potential reintroduction sites for mussels, and areas where more study may be required.

Subject Area

Ecology|Geographic information science|Conservation

Recommended Citation

Tyler N Skelton, "Geospatial assessment of threats to freshwater mussel populations within the Upper Duck River watershed" (2011). ETD Collection for Tennessee State University. Paper AAI1497842.