HR: 11:00h
AN: NB22C-03 INVITED     [Abstracts]
TI: Rapid Recovery of Chironomidae (Diptera) in Little Mill Creek (Kansas, U.S.A.) After the Decommissioning of a Waste Water Treatment Plant
AU: * Bouchard, R W
EM: bouc0048@umn.edu
AF: University of Minnesota, Department of Entomology, 219 Hodson Hall, 1980 Folwell Ave., Saint Paul, MN 55108-6125 United States
AU: Ferrington, L C
EM: ferri016@umn.edu
AF: University of Minnesota, Department of Entomology, 219 Hodson Hall, 1980 Folwell Ave., Saint Paul, MN 55108-6125 United States
AB: In June 1995 the Lenexa Waste Water Treatment Plant was decommissioned, providing an opportunity to study recovery of Chironomidae community structure in Little Mill Creek. Using pupal exuviae, weekly changes in the species richness and composition of Chironomidae emerging upstream and downstream of the effluent outfall was evaluated from two weeks before decommissioning to eight weeks post-decommissioning. Chironomidae emergence was clearly different between upstream and downstream sites both before and shortly after effluent input ceased. Before decommissioning, sites immediately downstream of the effluent had low species richness and were dominated by Chironomus riparius (Meigen) and other tolerant taxa, with some recovery at sites farther downstream. Two weeks after decommissioning, only sites immediately downstream of the former effluent were clearly impacted, but effects were reduced compared to pre-recovery collections. At five weeks post-decommissioning, species richness was only slightly lower at the sites immediately downstream of the former effluent and the composition of common species (i.e., >5% of relative abundance) was similar between upstream and downstream sites. Rapid recovery of chironomid emergence below the sewage effluent likely resulted from both colonization of drifting larvae from upstream sources and adult dispersal and oviposition, indicating rapid responses in emergence as water quality conditions improved.
DE: 9810 New fields (not classifiable under other headings)
DE: 9902 NABS Student Award Applied Research
SC: North American Benthological Society [NB]
MN: 2005 Joint Assembly