Responses of benthic insect communities to effluent from the abandoned Ferris-Haggarty copper mine in southeast Wyoming, USA

Six criteria were used to evaluate 12 metrics for their sensitivity to effluent flowing from the Ferris-Haggarty copper mine into Haggarty Creek and then into Battle Creek West Fork. Through the evaluation process, we found that the Shannon-Wiener index, the random runs value, and Ephemeroptera taxa richness appeared to best reflect the impacts that have occurred in both Haggarty Creek and Battle Creek West Fork. In addition, Ephemeroptera/Plecoptera/Trichoptera taxa richness, total taxa richness, and Plecoptera taxa richness, were useful in reflecting those impacts. In contrast, we found that the abundance ratios, the Hilsenhoff Biotic Index, as well as Trichoptera taxa richness, did not reflect the impacts that occurred in Haggarty Creek and Battle Creek West Fork. Finally, this study provided information about the benthic insect communities that are present in the impacted reaches of Haggarty Creek. Such information is needed to assess the potential of those reaches as habitat for the Colorado River cutthroat trout, Oncorhynchus clarki pleuriticus, which is a species of special concern to the Wyoming Department of Game and Fish.