This study focuses on two heavily-smelter damaged lakes in the Sudbury region of Ontario: Daisy Lake and Baby Lake (Figure 1). Historically, the Sudbury region was home to the largest underground nickel mining operation in the world and resulting smelter emissions damaged many of the surrounding lakes and decimated vegetation (Gunn et al, 2001). The damage resulting from the smelter emissions include lake acidification, heavy metal deposition, soil denudation, death and stunting of vegetation. Daisy Lake, Baby Lake, and their contributing watersheds were some of the most heavily impacted by the smelter emissions as they are located between 2.7 and 3.5km from the Coniston smelters that were active from the early 1900s until being decommissioned in the 1970s (Corston, Gillespie, & Gunn, 2014a; 2014b). As a result, the pH of these lakes decreased to 4.0-4.5 and heavy metal concentrations exceeded those that permit the existence of aquatic life (Corston, Gillespie, & Gunn, 2014a; 2014b).
Daisy Lake is a 36 ha lake located 3.5 km southwest of the abandoned Coniston smelter (Gunn et al, 2001). The copper and nickel smelter operated from 1913 to 1972 (Gunn et al, 2001). There was also an open roast yard near the smelter that operated between 1913 and 1918 (Gunn et al, 2001). Catchment J in Daisy Lake (Figure 1) was subject to liming treatment which effectively neutralized the pH of the drainage water (Gunn et al, 2001).
Figure 1. Delineated subcatchments corresponding to each delta for Daisy Lake and Baby Lake in Sudbury, Ontario.