The Metal Mining Effluent Regulation (MMER) requires metal mines in Canada to conduct Environmental Effects Monitoring (EEM) to assess the potential effects of mine effluent on receiving waters and their resident biota on a national basis. The EEM program (Environment Canada 2011) provides a framework for the consistent collection of data on five endpoints regarding fish health, and four endpoints regarding benthic invertebrate community structure. For fish health, the endpoints are condition, liver size, gonad size, weight-at-age, and age, and for benthic invertebrate-community structure the endpoints are density, taxon richness, the Bray-Curtis Index (BCI) and Simpson’s evenness. The stated primary goal is to determine if the MMER effluent regulations, on a national basis, are (on average) protective of the receiving environment (Environment Canada 2012).
Environment Canada has interpreted the national EEM data and concluded that measurable environmental impacts are being caused by individual mines and the mining industry at large (Lowell et al. 2006, Environment Canada 2012). The Mining Association of Canada (MAC) is concerned about the technical validity and strength of Environment Canada’s interpretation of the EEM data. Previously MAC retained independent technical expertise to review the scientific validity of Environment Canada’s administration of the Metal Mining Effluent Regulations (MMER), especially on a site-specific basis. Findings of errors and systematic bias in the interpretation of the EEM data resulted in publications documenting these findings in respected aquatic toxicology journals (Huebert et al. 2011; Huebert 2012a, b). The findings also encouraged discussion between MAC and Environment Canada in December 2011 to attempt resolution of the identified issues. The findings included a pseudo-replicated basic study design, incorrect designation of experiment-wise error, and biased calculation of the Bray-Curtis Index.