Delayed Recovery of Benthic Macroinvertebrate Communities in Junction Creek, Sudbury, Ontario, after the Diversion of Acid Mine Drainage

Abstract

Restoration of streams impacted by acid mine drainage (AMD) often require extensive and expensive engineering solutions, but the long-term effectiveness of these treatments in terms of improving downstream biological communities, is rarely tested. A rather novel treatment for the elimination of AMD at a site on Junction Creek in Sudbury Canada, involved damming and diversion of AMD deep underground, with subsequent limestone treatment of the waters outside the watershed. We used a rapid bioassessment technique to assess the recovery of benthic macroinvertebrate communities in response to this diversion. Biological summary metrics including taxa richness, EPT (sum of Ephemeroptera, Plecoptera, Tricoptera) richness, Simpson diversity, as well as multivariate descriptors of relative taxa abundance were used to compare the test site to nine reference sites. There was rapid recolonization of many families of benthic invertebrates but the site remained significantly impaired 8 years after the diversion, with a particular scarcity of large sensitive organisms. Multiple factors, including drought events, delayed or set back recovery. This study indicated that ecological risk managers need to consider both shortterm and long term (e.g., watershed revegetation) strategies to promote ecosystem recovery in such situations.

Acid mine drainage and stream recovery: Effects of restoration on water quality, macroinvertebrates, and fish

“…Local macroinvertebrate taxonomic richness, mean macroinvertebrate density, mean live biomass, and Shannon Wiener diversity index were all significantly higher in 2011 (post-restoration) than in 1967 (pre-restoration), and regional taxonomic richness throughout the watershed more than doubled after remediation efforts were implemented. These results are consistent with studies showing that degradation of water quality from AMD is typically associated with a reduction in the diversity and abundance of macroinvertebrates (Tomkiewicz and Dunson, 1977;Kimmel, 1983), and studies demonstrating biological recovery from AMD following restoration (Nelson and Roline, 1996;Gunn et al, 2010).…”

Freshwater Diatoms as Indicators of Combined Long-Term Mining and Urban Stressors in Junction Creek (Ontario, Canada)

“…Despite rehabilitation actions and improved physico-chemical properties, Junction Creek shows similar responses to what was observed in surrounding lakes where signs of biological perturbations are still present. For example, a study on macroinvertebrate assemblages from 2000 to 2008 suggests slow recovery in Junction Creek (Frood Branch) after diversion of acid mine drainage in 2000, when many large sensitive invertebrates were still lacking [2]. Although metal contamination has drastically been reduced in the region, Weber et al (2008) also showed biological impacts with increasing metal concentrations (Cd, Cu, Rb, Se, and Sr) in fathead minnow and creek chub along a downstream gradient in Junction Creek.…”

“…The health of Junction Creek was impacted by the contamination and degradation in its watershed, and showed highly impaired biological integrity [1]. Still nowadays, despite pollution control and rehabilitation actions having been undertaken, aquatic ecosystems in the region suggest slow recovery [2][3][4][5][6]. Mining activities are still present in the region, although under significantly more restrictive pollution control and regulation, and intensification of urban development represents a supplementary environmental threat.…”

Impacts and prognosis of natural resource development on aquatic biodiversity in Canada’s boreal zone

“…Three of those reported impacts that clearly show negative and long-lasting effects on invertebrate communities, especially reduced diversity, when receiving waters and sediments contain bioavailable metals. Recent studies in metal-contaminated lakes or streams continue to show lower invertebrate diversity than in uncontaminated systems, although some trends of recovery are evident where effluents or emissions have been reduced (Gunn et al 2010;Wesolek et al 2010). By contrast, Spencer et al (2008) found evidence of eutrophication and resultant increased invertebrate abundance and diversity downstream of metal mines.…”