'Catch it, kill it and dispose of it properly': Prussian carp invade southern Alberta lake

An invasive species of fish is taking over Frank Lake and the province says options to remove Prussian carp are limited so it is encouraging anglers to catch and dispose of them when caught.

No one knows when the invasive species was introduced into the body of water but Greg Wagner first saw them in the spring of 2019 and now there are thousands upon thousands. He's the volunteer caretaker at Frank Lake.

"Prussian carp are a nuisance," said Wagner. "They're an invasive species and shouldn't be here and we'll see what the long-term ecological effects are as time goes by, unfortunately."

Frank Lake is a water body just east of High River. It's a wetland conservation project and a popular spot for bird lovers. The lake is fed from treated effluent from the town and the Cargill plant.

"These fish I think maybe should be tested for contaminants or micro organisms to see if they pose a threat to public health," said Wagner.

That's because he sees many people using fish nets and taking buckets of them home. Wagner can only assume they're being cooked and eaten.

"It's tertiary treated from the town of High River and the Cargill plant and is it safe to consume these fish, is it safe to handle these fish?" said Wagner. "Just because of the sheer numbers of the fish that are leaving here, I think that's a big concern and could be a big health impact."

The province released a statement saying, "Alberta Environment and Parks will look into this specific instance when one of our team members is able to get out to the location."

Press Secretary Jess Sinclair added that Prussian carp can out-compete Alberta’s native fish species for food and habitat. Options to remove Prussian carp are limited in waters bearing other fish species, so Alberta Environment and Parks encourages removal of Prussian carp through angling.

"Prussian carp should not be returned to the water, if caught. Our advice to anglers regarding Prussian carp is: catch it, kill it and dispose of it properly. It is illegal to harvest and sell Prussian carp for food or bait. Although we appreciate the role angling plays in removing Prussian carp from our rivers and lakes, Alberta’s sport fishing regulations still apply," reads the statement.

Wagner says there is an upside for bird watchers in a lake filled with Prussian carp.

"Last summer there were 650 pelicans here," said Wagner. "We had a breeding population of 480 cormorants so they're here and their numbers are increasing because of the carp."