Whitefish populations below Libby Dam, which created Lake Koocanusa, have declined considerably in recent years. Monitoring in 2018 found that populations, which are usually 700 fish per 1,000 feet, were down 53 percent in 2018 and 55 percent in 2023. High levels of selenium, above state and U.S. limits, have been found in fish eggs and ovaries.
The selenium from the mines “is likely causing the decline,” said Jim Dunnigan, a fisheries biologist for the Montana Department of Fish, Wildlife and Parks who is studying the contamination. “It’s cause for serious concern.”
Wyatt Petryshen of Wildsight, the Canadian environmental group that monitors Teck’s operations, said environmentalists were worried about recent moves by Teck that split its operations into Teck Metals Corp. and Elk Valley Resources, which will own the coal-mining operation.
“There are very real concerns that Teck is trying to spin off the company to avoid paying for environmental damages while maintaining cash flow to their metal mining business,” Mr. Petryshen said.
Sheila Murray, chairwoman of Teck’s board, defended the change, saying it would be more profitable for shareholders and would “support a sustainable future for the benefit of employees, local communities and Indigenous peoples.”
U.S. officials and advocates said the International Joint Commission, the bilateral body, would be the best authority to seek ways to contain and reduce the mining pollutants. “We need a scientific advisory panel of both U.S. and Canadian scientists,” Mr. Sandborn said. “We need to get this to the International Joint Commission so that we have a proper watchdog.”
Jennifer Savage, a spokeswoman for the U.S. State Department, which oversees the United States’ role in the commission, said it wanted the international body to take the matter up soon.
“Indigenous communities along the watershed depend on these waters for cultural survival and for their survival,” said Ms. Savage, director of the department’s office of Canadian affairs. “We’re impatient. We are definitely eager to find a solution.”