Scientist challenges claims on selenium in Crowsnest Lake

A Saskatchewan scientist with nearly two decades of selenium experience said recent headlines about fish in Crowsnest Lake went beyond the evidence and risked confusing legacy impacts with what would be required under modern mining rules.

In a Sept. 4 phone interview, Dr. Monique Simair said she wrote her Aug. 2 analysis after seeing multiple outlets run the same story based on a bioRxiv preprint led by Alberta government scientists that reported high selenium in fish tissue from Crowsnest Lake.

A preprint is a scientific paper that is shared publicly before it has been peer reviewed. Peer review is the process where other experts in the field examine a study’s methods, data and conclusions to check for accuracy and balance before it is formally published. While preprints can spark early discussion, their findings are considered preliminary and may change once they undergo full scientific scrutiny.

“I really want to have accurate information communicated to people,” she said. “There’s this old saying, you know, I wondered why somebody wasn’t doing anything, and then I realized I am somebody. So, I decided it was time to start speaking up for science.”

Simair said the paper’s authors “went too far in their interpretations in order to essentially sell a story,” adding that scientific discourse should unfold through peer review. 

“If it’s going to be presented as an academic article, it should go through the academic peer review publication process,” she said, noting her comments were about process and interpretation rather than disputing the raw measurements.

The May 27 preprint reported selenium in fish ranging from 5 to 26 micrograms per gram dry weight, with 100 per cent of samples exceeding Alberta’s interim fish tissue guideline of 4 micrograms per gram. It framed the results as evidence that “any further coal mine development may well push the fishery beyond sustainability.” 

The paper also described the historic Tent Mountain and Grassy Mountain operations as mountaintop removal mines and highlighted legacy inputs to Crowsnest Lake from Crowsnest Creek, where selenium concentrations up to 24 micrograms per litre were recorded in 2021.

Simair’s critique argued the study itself acknowledged “clinical expression of selenium poisoning was not observed,” and that sediment selenium rose during the underground era and then plateaued after surface mining began. She also pointed to gaps in long-term water chemistry and confounding stressors such as stocking, angling pressure and whirling disease.  

“What we need to look at here is legacy sites versus current practices,” she said. “By opening a new mine, that actually requires that site to be elevated to modern standards. So that water would then get cleaned.” 

She said Canadian discharge rules and aquatic life guidelines are developed by teams of technical experts across disciplines, and that multiple proven water treatment technologies can meet Canadian limits when designed for site conditions.

Simair cautioned against loading the public debate with emotionally charged terminology. 

“As soon as we’re scared or excited, we’re not just thinking about the data and the science and the evidence. We aren’t being objective anymore,” she said. “If we want to talk about science, we need to stay objective because it’s really important to have discourse.”

She added that discussions about treatability often conflate two separate numbers, the discharge concentration at an outlet and the concentration after mixing in the receiving water. 

“People are saying they don’t think water is treatable, but what they’re actually saying is, I don’t like that guideline. And those are two different things to talk about,” she said.

On risk context, Simair noted the preprint itself reported no clinical symptoms of selenium poisoning during its assessment, while other pressures are present in the basin. 

“That to me is alarming to say that this system could collapse due to selenium, but they’re also saying there is no evidence of symptoms from the selenium,” she said.

Simair also raised practical trade-offs that regulators and operators weigh when applying lower limits and new technology. 

“Sometimes the treatment is [such that] the medicine is worse than the disease,” she said, pointing to byproducts, chemical use and cost-benefit considerations that must be evaluated against environmental gains.

She said Canadian standards for mine discharges are often lower than limits applied elsewhere and are separate from drinking water allowances. 

“Our cities don’t need to treat for it. Your drinking water, you’re allowed, depending [on] where you are, 20 to 50 times more selenium in your drinking water than a mine is allowed to discharge,” she said, emphasizing that guidelines target protection of aquatic egg-laying vertebrates.

Simair disclosed she consults broadly to mines, First Nations and governments and said she has done consulting work for Grassy Mountain. 

“They did not ask me to review this. They did not ask me to weigh in on this whatsoever. It was a surprise for them,” she said.

In her Aug. 2 post, Simair argued that reopening legacy sites under current regulations could, in some cases, reduce selenium loadings if projects are required to meet today’s discharge limits and implement treatment. Her commentary also questioned the use of “mountaintop removal” in relation to the Crowsnest operations, and said the sediment record presented in the preprint did not support the claim that surface mining drove continuing increases.

The authors of the preprint concluded that high fish tissue selenium in Crowsnest Lake, combined with other stressors, suggests new coal development “may well push the fishery beyond sustainability.” 

The study remains under preprint status on bioRxiv and has attracted wide media attention since early June.

Residents can read Simair’s analysis and the Cooke preprint directly to compare methods, data and interpretations. The Herald will continue to follow peer review outcomes and any regulatory responses as they emerge.

Visit https://www.moniquesimair.ca/insights/selenium-coal-mining-spin-vs-science and https://www.biorxiv.org/content/10.1101/2025.05.22.655156v1 to read the analysis and preprint.