Effects of Lowhead Dams on the Ephemeropterans, Plecopterans, and Trichopterans Group in a North American River

ABSTRACT

We assessed the effects of lowhead dams on the EPT group (ephemeropterans, plecopterans, and trichopterans) by sampling habitat and macroinvertebrates monthly from November 2000 to October 2001 at eight gravel bars centered around two lowhead dams on the Neosho River, Lyon County, Kansas. Sites included a reference and treatment site upstream and downstream from each dam. Percent EPT was greater at reference sites than upstream treatment sites, and was positively correlated with stream velocity and %gravel in the substrate, but negatively correlated with substrate compaction and %boulder in the substrate. These results are similar to those for large dams and suggest that differences in habitat around these lowhead dams are unfavorable for EPT taxa, a finding important to the conservation and restoration of biotic integrity in riverine ecosystems.