Mountain top removal coal mines in the historic Crowsnest Pass present a clear and present danger to downstream fish populations even decades after their closure, according to a new scientific paper funded by the government of Alberta.

The study, which examined the biological impact on fish from historic coal mining on Tent Mountain, found the legacy of open-pit mining “can persist long after mining operations end,” resulting in devastating losses for fish containing some of the highest levels for selenium ever recorded in the province.

The researchers also concluded that high selenium pollution recorded in fish netted from Crowsnest Lake strongly suggest that “any further coal mine development may well push the Crowsnest fishery beyond sustainability.” In other words, more development may well finish off the region’s distinct biological diversity.

That scientific warning contradicts the pro-coal policies of Premier Danielle Smith. Her government actively supports new coal mining projects in the Rockies, including reviving the controversial open-pit Grassy Mountain project even though a majority of Alberta’s population remains steadfastly opposed to endangering the province’s water security.