Okanagan area lake illegally stocked with perch will be poisoned

A mountain lake west of Kelowna has been closed to sport fishing and will be poisoned because it’s infested with an invasive fish species.

Yellow perch have been illegally introduced into Windy Lake.

“We think someone put them in there to create a fishery they could then utilize and catch fish. But it’s something we’d like to see stopped,” says Andrew Klassen, senior fish biologist with the Fish and Wildlife Branch.

The perch are prolific breeders and voracious feeders and can out-muscle the native Rainbow trout.

They can also badly deplete the insect food chain affecting other wildlife like bats, birds and amphibians.

A major concern is the ecological impacts, particularly for salmon and trout, should the perch drop out of Windy Lake which empties into the Thompson River drainage system.

Story continues below advertisement

“We don’t have any of these species in the lower portions of the watershed and we want to make sure we keep them out,” says Klassen.

So Windy lake will be treated with an organic pesticide at a cost of about $100,000.

“Rotenone is a bio-degradable compound found in the roots of various bean varieties, says Klassen. “In low doses it quickly kills all the fish but it wouldn’t affect anything else other than fish and a few invertebrates which would quickly recover.”

The kill-off is scheduled for the fall of 2017.

The lake will then be re-stocked with trout and re-opened to fishing.

A reward of up to $20,000 is available for information that leads to the conviction of someone who illegally transports or stock invasive fish species in B.C. waters.

The penalty for such offenses is a fine up to $500,000 and six months in jail.