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, scott.grubbs@wku.edu
Taylor, J, M, Western Kentucky University, Bowling Green, USA, jason.taylor@wku.edu
 
Artificial hydrologic impact on the longitudinal distribution of lotic macroinvertebrates in the Green River, Mammoth Cave National Park, Kentucky
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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.