Two popular East Kootenay lakes won't hear the buzz of a fishing reel anytime soon.
Fussee Lake, south of Elko and New Lake, west of Cranbrook, have been closed to sport fishing because illegally introduced yellow perch and largemouth bass are decimating native and stocked species like trout.
"There's been illegal introductions over the last few years that we discovered last year," senior provincial fish biologist Jeff Burrows told Radio West host Alya Ramadan.
"They compete with native species or stocked trout that we stock to keep a sport fishery. ... Also, they're predators, so they'll eat the native fish or the trout we stock."
Burrows says the invasive fish are also eating native amphibians and could be introducing new parasites or diseases they carry with them.
He says illegal fish introductions presumably happen because some anglers want to start a different kind of fishery in the lakes.
It's hard to know exactly why, he says, because it's difficult to catch someone illegally introducing fish without a witness or someone reporting it.
Burrows says authorities have a "zero tolerance" policy for illegal introductions and the closing of the lakes is meant to be a disincentive for further introductions.
"[Introductions] are not very common now. I think most people realize that it's a maneuver from the shallow end of the gene pool," he said. "In our region, the Kootenays, these are the only illegal introductions we know of in the last eight or nine years. "It's rare, but troubling."
He says the next steps will be a biological assessment of the lakes before developing a further plan to eradicate or suppress the perch and bass.
A plan will be developed over next year or so, Burrows says, but the lakes could be closed for several years.