British Columbia Mine Reclamation Symposium

From tailings basin to aquatic ecosystem : the ecological recovery of two waterbodies in Kirkland Lake, Ontario, Canada Chute, A.; Dombrowski, N.

Abstract

A study of the aquatic ecosystems of Kinross Pond and the Eastmaque tailings basin were conducted in the summer of 2012 to assess the recovery of these former tailings facilities. The objective of the study was to evaluate the potential for a closed tailings basin, proposed as a closure lake, to support aquatic life once it is flooded at closure. A study of water quality, sediment quality and aquatic communities was conducted on the Eastmaque basin and Kinross Pond as analogue representation to the proposed closure lake. Fish populations were sampled using minnow traps, seine nets and gillnets. Benthic invertebrate, sediment and water quality sampling were also completed in each pond. Kinross Pond and the Eastmaque basin support different productive fish communities. Kinross Pond supports a fish community composed of four small-bodied fish species: northern redbelly dace (Chrosomus eos), finescale dace (Chrosomus neogaeus), golden shiner (Notemigonus crysoleucas) and brook stickleback (Culaea inconstans). Evidence of recruitment between size classes of each species (i.e. the presence of young-of-year) was documented. The Eastmaque basin supported five species of fish: yellow perch (Perca flavescens), northern pike (Esox lucius), spottail shiner (Notropis hudsonius), blacknose shiner (Notropis heterolepis) and common shiner (Luxilus cornutus). Young-of-year northern pike and yellow perch were captured along with large adult individuals of each species. The ecological recovery of Kinross Pond and the Eastmaque basin assessed during this study indicates that in the years after the Lakeshore basin becomes part of a closure lake, it will potentially sustain a relatively complex community of fish and benthic invertebrates. This study has shown that viable aquatic ecosystems can be restored in bodies of water previously used for industrial purposes, specifically for the storage of gold mine tailings. Removal of these tailings, and the passage of time, can return a tailings storage basin to a pond or lake with a functioning aquatic ecosystem with few additional rehabilitation measures.

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Attribution-NonCommercial-NoDerivatives 4.0 International