Using artificial streams to assess the effects of metal-mining effluent on the life cycle of the freshwater midge (Chironomus tentans) in situ.
In 2002, we developed an in situ life-cycle bioassay with Chironomus tentans in artificial streams to evaluate the effects of a complex metal mine effluent under ambient environmental conditions. The bioassay was tested in the field using effluent from the Copper Cliff Waste Water Treatment Plant at INCO (Sudbury, ON, Canada). Chironomus tentans were exposed throughout the life cycle to 45% Copper Cliff effluent, which is the average effluent concentration measured in Junction Creek (ON, Canada), the natural receiving environment. Chironomus tentans in the effluent treatment exhibited reduced survival (p = 0.001), reduced total emergence (p = 0.001), increased time-to-emergence (p = 0.001), and reduced hatching success (p = 0.001) relative to animals in the reference water treatment. Chironomus tentans in the effluent treatment were not significantly different from the reference in terms of growth, sex ratio, number of egg cases/female, and number of eggs/egg case. This research showed how a life-cycle bioassay could be used in situ to assess metal mine effluent effects on a benthic invertebrate.
Hruska
Kimberly A
KA
National Water Research Institute, Environment Canada, Saskatoon, Saskatchewan S7N 3H5, Canada. hruskak@interchange.ubc.ca
Dubé
Monique G
MG
D000818:Animals; D001681:Biological Assay / Q000379:methods; D002170:Canada; D002683:Chironomidae / Q000187:drug effects* / Q000254:growth & development; D005260:Female; D007220:Industrial Waste / Q000032:analysis; D007814:Larva / Q000187:drug effects; D008018:Life Cycle Stages / Q000187:drug effects*; D008297:Male; D008670:Metals / Q000032:analysis / Q000633:toxicity*; D008906:Mining; D012098:Reproduction / Q000187:drug effects; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000633:toxicity*
D007220:Industrial Waste; D008670:Metals; D014874:Water Pollutants, Chemical