Effects of a decade of selenium emission reductions on mercury accumulation in aquatic biota in the Sudbury region of Ontario

Control of smelting emissions in the Sudbury (Ontario, Canada) area has dramatically decreased the amount of selenium (Se) deposited onto the surrounding landscape. Historically, Se emissions in Sudbury correlated with lower total mercury (Hg) and methylmercury levels (MeHg) in tissues of zooplankton, amphipods (Hyalella azteca), mayflies (Stenonema femoratum), and young-of-the-year perch (Perca flavescens). In 2017, ten years following emission...