Predicting Aquatic Ecosystem Health in the Southeastern United States

Species represent a wide range and combination of traits, (i.e., behavior, feeding) some of which are unique and essential to ecosystem functioning, and some which are redundant within a community. This “functional diversity” (FD) is not always mirrored by traditional measures of species richness. Here we take a trait-based approach to explore patterns of FD in fish communities across the southeastern US. We obtained species presence/absence data from the MARIS and USGS Nonindigenous Aquatic Species databases, and scored trophic traits for the 386 fish species using the Virginia Tech FishTraits Database, primary literature, USFWS reports, and fish identification texts. We calculated species richness and FD (using the functional dispersion metric) for 121 sub-basins in the southeastern US. In general, we found high functional diversity throughout the eastern highland and Appalachian regions and lower functional diversity in the Coastal Plain and Piedmont areas. Our results suggest that sub-basins with similar species richness but different FD values are likely a result of differences in river channelization, development, and habitat complexity. Going forward, we plan on relating FD to additional ecosystem health indicators (i.e., impervious surface and percent natural cover) to reveal potential correlations.