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Presented at the NABS Annual meeting, Vancouver, British Columbia, 2004
in Ecotoxicology
Preliminary analysis of benthic invertebrate community data from historical biological monitoring at Ontario minesites
W.A. Plant and N. Ali. Environmental Protection Branch, Environment Canada, Downsview, Ontario, Canada M3H 5T4
On June 6th, 2002 Canada promulgated amended Metal Mining Effluent Regulations. The requirement to conduct Environmental Effects Monitoring (EEM) is a key component of these regulations. An EEM study consists of site characterization, effluent and water quality monitoring, sublethal toxicity testing, a fish survey, and a benthic invertebrate community survey. In December 2003, mines subject to the regulations had to submit either a study design or a historical data report. The historic reports were required to include the results of biological studies completed before December 6th 2002, which determined whether effluent was causing effects to fish, or benthic invertebrate communities. Ten historic benthic invertebrate surveys have been analyzed from Ontario sites. In most studies benthic invertebrates were collected from both streams and lakes. Both depositional and erosional substrates were sampled. The most common samplers used were petite Ponar and Ekman grabs. All but two mines used study designs with replication. Effects on the benthic invertebrate community were observed at 60 % of the mines. In all cases these effects could be due to mine effluent but confounding factors were present at 50 % of the sites.
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