Changing Planet

Addressing Cumulative Impacts of Climate Change and Development on Freshwater Fish in Northern Ontario

By Cheryl Chetkiewicz

Ontario is a Canadian province built on mining and mineral exploration. Over the past two decades, the provincial government has encouraged and facilitated new mines in Ontario’s Far North—a large, remote and largely roadless region that is the homeland for nearly 40,000 First Nations.

The “Ring of Fire” mineral belt, located approximately 350 km north of Thunder Bay, is a massive, ore-rich area, including the largest chromite deposit in North America, which is worth an estimated $60 billion. Getting these minerals to market will require new all-weather roads and transmission lines.

Mineral exploration and mining for diamonds and gold are important drivers of land use change in Ontario’s Far North. credit: Garth Lenz.

The Ontario Government has invested close to $7 million negotiating with Matawa First Nations—nine First Nation communities in the “Ring of Fire”—about new infrastructure in their homeland. In May 2017, the government grew impatient with the slow progress on these negotiations and proceeded to work with three First Nations directly to build new roads that will open up the region for mining and access.

At the same time, the Ontario Government began concurrently working with these communities to develop community-based land-use plans. These plans will determine where protected and industrial development can occur, including roads and mines. The government is mandated to maintain the ecological and cultural integrity of the region while protecting at least 50 percent of the region and recovering species at risk such as caribou, wolverine, and lake sturgeon.


In reality, neither project-level impact assessments nor community-based land-use planning led by the Government can address the cumulative impacts of new roads, transmission lines, and mines across large remote regions like Ontario’s Far North. These processes fail to address the regional impacts of multiple developments and climate change on the values that define Ontario’s Far North such as freshwater fish.

Ontario’s Far North is home to more than 50 freshwater fish species. Unlike southern Ontario, fish communities here remain largely unaltered by species introductions, stocking, over-exploitation, and pollution. The region contains significant freshwater habitats, including five of Canada’s 12 remaining undammed watersheds—a rare occurrence across much of North America. Finally, the Far North contains the third-largest wetland in the world, one of the most productive subarctic environments on the planet.

Importantly, freshwater fish are highly valued by First Nations living in the region as a source of both food and income. First Nations have rights to harvest fish and to maintain their spiritual and cultural relationships that have sustained them for millennia.

Freshwater fish provide important economic opportunities for recreational fishers. Finally, intact freshwater systems provide climate regulation by storing vast amounts of carbon and flood and erosion control for coastal communities.

Freshwater fish communities in other parts of Ontario are already impacted by overfishing, pollution, water extraction, diversions, and fragmentation of rivers and streams by roads and dams.

In Ontario’s Far North, we have an important opportunity to maintain these globally significant freshwater ecosystems, their freshwater fish communities, and the values they sustain.

But the provincial approach to environmental planning proceeds without a good understanding of what the rate, intensity, and location of industrial development and climate change will be on freshwater fish and their habitats. We also lack basic scientific baseline data for fish in the region to help consider the future for fish in the region.

Both resident and migratory brook trout are found in NORTHERN Ontario. Fly-in sport fisheries contribute to the tourism industry critical to the northern Ontario economy. credit: Sean Landsman/Engbretson Underwater Photography.

As conservation scientists, WCS (Wildlife Conservation Society) Canada focuses on research to improve planning and decision-making. We modeled what might happen to fish populations in the face of new roads, transmission lines, hydroelectric dams, and climate change over the next 50 years. We compiled information on mineral claims, mines, logging, and hydroelectric plans together with natural disturbances such as fire and the latest climate data. We created two different scenarios of what the future may look like based on a high and low rate of industrial development.

Finally, we brought freshwater fish experts together in a workshop to describe the relative impact of each of these forces on specific fish species. We put all this information together in computer models that could project the combined impact of these stressors on freshwater fish species.

Lake sturgeon occur in all major rivers of nORTHERN Ontario and require unfragmented watersheds to thrive. credit: Engbretson Underwater Photography.

Our results provide a picture of what the future might look like for walleye, lake sturgeon, lake whitefish, and brook trout 50 years from now. Land use change increased dramatically under our high-development scenario, particularly in the southern parts of the region due to roads associated with forest management.

Roads fragment watersheds, affect water quality, and can lead to overfishing as anglers seek new fishing opportunities. Further north, the main driver of land use change for fish was new dams and associated flooding, as well as new mines and roads associated with these developments.

The combination of these changes on the land with climate change, however, really raised red flags, particularly for these species that are well adapted to cold and cool water temperatures.

Water temperatures throughout the region have reached unhealthy levels for species such as walleye, lake sturgeon, lake whitefish, and brook trout. Without proactive planning, these species will be challenged by warming climates and well-understood impacts associated with road crossings and flooding due to dams.

Unfortunately, the combination of land use pressure and climate change for fish in more intact regions like Ontario’s Far North is being ignored in the provincial government’s approach to planning in northern Ontario.

The “business as usual” approach to planning (and monitoring) does not address these cumulative effects and does not lead to a holistic vision for how to conserve ecological and cultural values in the face of new land use and a changing climate.

Our research does not paint a pretty picture of the future for Ontario’s northern fish, but it is better to know what the potential outcomes of our actions might be rather than rely on the current piecemeal and sector-based approach to planning land use and considering climate change in the north.

Now is the time for the Government of Ontario to assume leadership through progressive, regional land-use planning and regional environmental assessment before Ontario’s northern freshwater—and the communities that depend on them—find themselves in hot water.

Dr. Cheryl Chetkiewicz is a conservation scientist and landscape lead with WCS Canada.


WCS saves wildlife and wild places worldwide through science, conservation action, education, and inspiring people to value nature.

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