Assessing the Potential Cumulative Impacts of Land Use and Climate Change on Freshwater Fish in Northern Ontario
The study is the first to project the potential impacts of development on freshwater systems in a 440,000 km2 region of northern Ontario over the next 50 years. The study examined the impact of high- and low-growth development scenarios that incorporated forestry, mining, and hydroelectric development, as well as climate change and forest fire. The response of fish populations was assessed by applying expert-derived models that describe relationships between simulated stressors (e.g., roads, dams, forestry activities, temperature) and species-specific fish sustainability indices (FSI) for walleye, lake sturgeon, lake whitefish, and brook trout. All four species exhibited increased risk over the simulation period, although lake whitefish were more tolerant of simulated changes in land use and climate change. Overall, climate change was the most influential driver of risk to freshwater fish, followed by hydroelectric dams. Climate change consistently exacerbated the effects of land use and natural disturbance changes under both scenarios – FSI declined faster or further when land use was combined with climate change.