1. Continue to investigate spatial and temporal patterns in mercury concentrations in fish in lakes in the Mackenzie River Basin with a focus on predatory fish in smaller lakes near Fort Simpson but also including Great Bear Lake 2. Assess temporal trends in mercury concentrations and influencing factors, e.g., climate change 3. Conduct sediment core studies as opportunities allow to characterize long-term trends in mercury deposition and productivity 4. Integrate the findings of this study with our mercury trend monitoring in Great Slave Lake and the western provinces.