The Effects of Beaver Dams on Macroinvertebrate Communities of a Southeastern Coastal Plain Stream During Drought Conditions

Beaver dams have been shown to alter stream ecosystems by changing the structure and function of invertebrate communities under varying environmental conditions and in different geographic regions. This study assessed the influence of beaver dams on macroinvertebrate communities in a blackwater river in southeast GA. We examined benthic core samples and physiochemical parameters in six stream reaches, three with beaver dams and three without, of the Ohoopee River. This study was performed during the extreme to exceptional drought conditions between June 2011 and January 2012. Macroinvertebrate assemblages, organic matter standing stocks, and physiochemical parameters were compared within reaches with beaver dams (upstream vs. downstream) and between reaches (dams vs. without dams). Preliminary results of our study indicate that, during these severe conditions, beaver dams have little effect on macroinvertebrate assemblages, organic matter standing stocks, or physiochemical parameters. We believe this to be a result of little to no flow occurring during this period due to the low gradient of the Southeastern Plain and drought. This suggests that flow rates are the major driver influencing changes in beaver impacted stream.