USING BIVALVE DEATH ASSEMBLAGES AS AN INDICATOR FOR STRESSED RIVER ECOSYSTEMS

With increasing human influence on river ecosystems, it is important to be able to identify when a community is stressed and in what ways the ecosystem is being affected. While living communities are often well-studied, death and subfossil assemblages are an underutilized source of reliable data on recent ecosystem changes. Freshwater mussels are of particular interest in these communities because they are critically endangered and are often key components of these ecosystems.

The Land Between the Lakes National Recreation Area, located in western Kentucky and Tennessee, is bordered by man-made Kentucky Lake and Lake Barkley. Both lakes have been affected by damming, agricultural runoff, recreational use, and more in the ~75 years since their creation. Along with an extensive shell collection at Murray State University dating back to the early 1980s, water quality information has been recorded in the area since 2005 by the Hancock Biological Station and Four Rivers Watershed Watch. Partnered with modern bivalve assemblage samples, we hope to use the historical assemblages collected to detect an ecological signal of anthropogenic impacts in the area. Compared to other ecosystem monitoring methods which tend to be extensive and time-consuming, the methods for doing this sort of study are inexpensive and easily replicated, and modern freshwater mussels are often readily available. If an ecological signal can be identified, we would be able to provide an easily-applied ecological proxy for human influence in this sort of aquatic environment that could be used in other, similar areas to help conserve at risk-populations.