Impacts of forest harvesting on mercury concentrations and methylmercury production in boreal forest soils and stream sediment.

Methylmercury (MeHg) is the most neurotoxic and bioaccumulative form of mercury (Hg) present in the terrestrial and aquatic food sources of boreal ecosystems, posing potential risks to wildlife and human health. Harvesting impacts on Hg methylation and MeHg concentrations in forest soils and stream sediment are not fully understood. In this study, a field investigation was carried out in 4 harvested and 2 unharvested boreal forest watersheds, before and after harvest, to better understand impacts on Hg methylation and MeHg concentration in soils and stream sediment, including their responses to different forest management practices.

Watershed characteristics and chemical properties govern methyl mercury concentrations within headwater streams of boreal forests in Ontario, Canada.

Methyl mercury (MeHg) concentrations in boreal headwater streams are influenced by complex natural processes and disturbances such as forestry management. Understanding drivers of MeHg within boreal streams in Ontario, Canada, is of particular interest as there are legacy MeHg concerns. However, models accounting for the complexity of underlying processes have not yet been developed.

Alternative migratory strategies related to life history differences in the Walleye (Sander vitreus).

Background: While Pace of Life Syndrome predicts behavioural differences between individuals with differential growth and survival, testing these predictions in nature is challenging due to difficulties with measuring individual behaviour in the field. However, recent advances in acoustic telemetry technology have facilitated measurements of individual behaviour at scales not previously possible in aquatic ecosystems.

Methods: Using a Walleye (Sander vitreus) population inhabiting Black Bay, Lake Superior, we examine whether life history characteristics differ between more and less mobile individuals as predicted by Pace of Life Syndrome.

Climate and landscape conditions indirectly affect fish mercury levels by altering lake water chemistry and fish size.

Mercury pollution is a global environmental problem that threatens ecosystems, and negatively impacts human health and well-being. Mercury accumulation in fish within freshwater lakes is a complex process that appears to be driven by factors such as individual fish biology and water chemistry at the lake-scale, whereas, climate, and land-use/land-cover conditions within lake catchments can be influential at relatively larger scales. Nevertheless, unravelling the intricate network of pathways that govern how lake-scale and large-scale factors interact to affect mercury levels in fish remains an important scientific challenge.