New study details impacts of mining on salmon habitat, even hundreds of miles downstream

Simon Fraser University professor Jon Moore (left) and Mark Connor (right), fisheries coordinator for the Taku River Tlingit First Nation, stand on the banks of the Tulsequah River, which flows past Chief Tulsequah and New Polaris Mines. (Photo courtesy of Chris Sergeant)

A new study shows that mines can impact watersheds hundreds of kilometers downstream and for years to come. The paper’s authors say their analysis underscores the need for a more comprehensive consideration of mine risks to protect salmon watersheds across the Northwest.

There are thousands of coal and metal mines, active and inactive, scattered across northwestern North America. A study published earlier this month in the journal Science Advances found a consistent pattern of damage to salmon habitat and watersheds at some of these mines.

“It’s basically compelling evidence,” said Guy Archibald, executive director of the Southeast Alaska Native Transboundary Commission, a coalition of 15 tribal governments advocating for the protection of watersheds shared by Alaska and British Columbia in Canada as well as tribal representation in decision-making for BC mines. He says the study is groundbreaking.

“We have observed for decades that mines in watersheds occur and then salmon populations are harmed,” Archibald said. “But there has never been a direct link between mining activities and harm to salmon. This article goes far to show it.

“I think that’s one of the things that’s really unique about this paper,” said study co-author Jonathan Moore, a salmon ecosystem scientist and professor at Simon Fraser University. in Vancouver, British Columbia. “It brings together the cutting edge science of how these really complicated and changing river systems work with cutting edge mining understanding and how it is regulated.”

Moore says the newspaper does not oppose mining.

“What it is,” he said, “is to advocate for the incorporation of the best science available to guide mining, so that it can be more sustainable.”

The study’s lead author, Chris Sergeant, is a research scientist at the University of Montana’s Flathead Lake Biological Station. He says the interplay of mining effects on salmon watersheds is compelling in part because it’s so complex.

“You need engineers, biologists, hydrologists, governance and policy makers,” the sergeant said. “They all play a role in the mining world and how mining could potentially impact salmon – and in such an important place like northwestern North America, including the south- east of Alaska, it’s one of the last best places for fish in the world.”

The sergeant says there is no one stop shop for mining data, so they had to tap into various sources – US Geological Survey databases, data from mining industry resources, government agencies and academic literature. The study authors found many examples of mines having negative impacts on watersheds, even long after closure.

“We highlight a river in the Coeur d’Alene watershed in Idaho, where even seventy years after mining ceased, the pollution that was sustained from that work continues to lower the populations of fish and aquatic insects in this stretch of river,” the sergeant said.

It can be a similar story hundreds of miles from the mines and across international borders.

“In the Elk Valley watershed in southern British Columbia, which flows into the Kootenay River, flows through Montana and Idaho back into British Columbia, there is selenium pollution from mining coal mines located 250 kilometers downstream,” the sergeant said. “And that wasn’t really considered before these mines were built.”

The US government is taking note. Last month, the Biden administration called on the Canadian government to participate in a joint investigation into this selenium pollution in the transboundary Elk Valley watershed. In 2020, Congress committed millions of dollars to transboundary watershed monitoring projects.

Whether mines and watersheds straddle borders or not, the sergeant also notes that mines are being proposed and built in more extreme environments – on mountains, across glaciers – because easy-to-reach areas are already being mined.

“You have these engineering prowess to build mines in places where there are no roads or a lot of humans,” the sergeant says, “And then on top of that you have climate change coming , where we have more intense rains, more landslides, more floods, more droughts.”

This places additional, hard-to-predict pressures on mine infrastructure. And extreme weather events are happening with increasing frequency, says fellow co-author Nikki Skuce. She is director of the Northern Confluence Initiative and co-chair of the BC Mining Law Reform Network, a consortium of academics and community organizers advocating for changes to mining law in the province.

“We were hit with a heat dome, atmospheric rivers, catastrophic flooding, all within six months last year,” Skuce said. “There really needs to be a step in the environmental assessment process for projects as well as existing infrastructure like tailings dams to look at these climate risks.”

Tailings dams are earthen structures used to contain solid or liquid mining waste.

The sergeant says a prime example of unforeseen climate impact is the Red Dog mine in western Alaska, which was built in 1989.

“Because of unforeseen permafrost thaw, their water treatment facilities and open pits are submerged in more water than anyone ever imagined,” Sergeant explains, “and this a few decades later. the start of the project. Those are the kinds of concerns — if we build these bigger and bigger mining projects, [taking into account the changing climate,] can we even do the engineering properly? »

He points out that mining is essential for the transition to a low-carbon future. Copper and other minerals are essential components of batteries for electric cars and other low-carbon alternatives.

“But this decision to build a big mine is going to impact the earth for decades, if not centuries. And that needs to be thought through very carefully,” he said.

Moore says the two-year process of setting up the study has also revealed what he calls “really massive black holes” in our understanding of the extent and impact of mining.

“Mining companies and other industries, at least in Canada, don’t necessarily need to share their data. It’s exclusive,” Moore said. “So the information that underpins their environmental assessments, underpins their monitoring, doesn’t all see the light of day. I think that’s a real key challenge in terms of trying to assess the real risks of these projects.

For the authors of the study, the data indicate the need for better transparency, greater consideration of the cumulative effects of mines and the complex environmental stressors that could impact mines and basins. slopes due to climate change.

“I think we hope this document can be a resource to help people make decisions in these landscapes,” Moore says, “to help people understand what might be at stake and what can be done about it. topic, where the policies might need to be improved, where the science can be improved, where we need to think about who is part of these conversations.”

On her side of the border, Skuce says she and BC Mining Law Reform are pushing to improve Canada’s tailings dam safety standards and water management, in part by closing loopholes in the environmental assessment process. which allows the modification of mining permits.

On the US side, for Archibald and the Tribal Coalition, the study is clear evidence that the BC government should consider a much wider range of possible impacts when authorizing mines.

“If they don’t talk to the downstream communities, if they don’t learn how those communities use the resource (salmon) and depend on the resource, then they’re making a decision without any information,” Archibald said. “That’s no way to manage a mine and a habitat.

Mining Association of BC, a mining industry group, did not respond to a request for comment.


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