HR: 1330h
AN: NB33G-05    [Abstracts]
TI: Short Term Effects of Dam Removal Upon Trichopteran Communities
AU: * Kroiss, S J
EM: sjkroiss@wisc.edu
AF: Center for Limnology University of Wisconsin, 680 N. Park St. , Madison, WI 53706 United States
AU: Rogers, K L
EM: kristyrogers@wisc.edu
AF: Center for Limnology University of Wisconsin, 680 N. Park St. , Madison, WI 53706 United States
AU: Stanley, E H
EM: ehstanley@wisc.edu
AF: Center for Limnology University of Wisconsin, 680 N. Park St. , Madison, WI 53706 United States
AB: To determine the impact of dam removals upon in-stream insect communities, we monitored the removal of two small dams on Boulder Creek, a second order trout stream in Wisconsin. We used six Trichopteran genera (Brachycentrus, Glossosoma, Ceratopsyche, Lepidostoma, Pycnopsche, and Dolophilodes) as indicators of the overall effects of these dam removals. Benthic samples were collected upstream and downstream of the dams before and after the removals. Prior to removal, densities decreased gradually in the upstream and downstream reaches. Immediately after removal, there was an 83% decrease in total downstream density compared to an upstream decrease of only 34%. In the six weeks following removal, the downstream density increased by 255%, approaching pre-removal densities, while the upstream density showed no major change. The decrease in population densities downstream was most likely due to scouring and burial by reservoir sediments during the removal. Rapid downstream recovery following removal was likely due to recolonization from upstream populations. Overall, effects of the removals were extremely brief (6 weeks or less), demonstrating that the removal of these dams was not a major disturbance to the Trichopteran community.
DE: 1803 Anthropogenic effects
DE: 1899 General or miscellaneous
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly