SS3.21 Deconstructing Rivers: The Ecological, Geomorphic, and Social Consequences of Dam Removal
Date: Thursday, June 13, 2002
Location: Poster Session - VCC
GrubbsSA, Western Kentucky University, Bowling Green, USA,
Taylor, J, M, Western Kentucky University, Bowling Green, USA,
Artificial hydrologic impact on the longitudinal distribution of lotic macroinvertebrates in the Green River, Mammoth Cave National Park, Kentucky
At the downstream end of the Green River in Mammoth Cave National Park (MCNP), Kentucky, is an antiquated U.S. Army Corps of Engineers low-head dam (Lock & Dam #6) that was disabled in the 1950’s. Recently, the Corps has proposed to deauthorize and remove the dam. The intent of the current research was to assess the influence of Lock & Dam #6 on the macroinvertebrate community of the Green River in MCNP, and serve as a pre-manipulation dataset to track potential recovery following dam removal. Hester-Dendy multiplate samplers and rock baskets were each placed at ten locations within three distinct hydraulic zones (impounded, transitional, erosional). Samples were retrieved after 48-62 days. The community in the impounded zone was dominated by Chironomidae and Oligochaeta, and functional feeding groups mainly by gathering-collectors. The erosional zone supported a much broader assemblage across major invertebrate groups, including EPT taxa and elmid beetle larvae. Functional feeding groups were near-equally represented. Overall, macroinvertebrate communities were clearly influenced according to the degree of flow hindrance.