Grant: Alliance Grants

Solving the problem of harmful algal blooms and reducing the likelihood of negative effects on human health requires a detailed understanding of lake ecology and geochemistry, moreso in subarctic lakes where blooms have historically been absent. The subarctic is 1/6 of Canada's land mass but is a poorly studied area where human habitation is sparse and rates of resource extraction are increasing. The central and western subarctic is particularly vulnerable to climate change effects (temperature and precipitation) and has already warmed by 3°C and precipitation increased by 25% since records began in 1943. Blooms have worsened in many areas of Canada with elevated nutrient loading but even some remote lakes are affected. Jackfish Lake in the Northwest Territories is a subarctic lake now experiencing annual cyanobacterial blooms. The catchment around the lake has been developed as Yellowknife has grown and the lake receives thermal effluent from a nearby powerplant This creates warmer conditions more favourable to cyanobacteria growth than in the past. The most common taxa in Jackfish Lake is Planktothrix, which is associated with the production of a suite of toxins such as microcystin and anatoxin-a that have potentially harmful effects on humans and wildlife. Here, we will co-develop a detailed understanding of the state of Jackfish Lake, assess the current toxin risk, bloom drivers, and undertake a first assessment of potential interventions to improve water quality in this small but important Northwest Territories lake. Current evidence suggests blooms in Canada, and globally, will continue to become more severe. The knowledge and skills developed from this project will set the stage for both follow-up research on applying mitigation strategies to Jackfish Lake as well as building capacity for further northern-based monitoring and research on bloom-affected subarctic lakes.