Removing invasive Prussian carp from Innisfail, Alta. pond a tall order: province

Prussian carp invade Innisfail pond An invasive species of fish is overwhelming a pond in Innisfail. Tyson Fedor reports

Innisfail, Alta. — An invasive species of fish is currently overwhelming a pond in a central Alberta town and, according to the province, there's little that can be done to permanently remove the intruders.

Dodd’s Lake in Innisfail has experienced a recent influx of Prussian carp and experts have their suspicions for what prompted the arrival of the highly adaptable fish.

"It can actually use the sperm of other fish to clone itself," said Nicole Kimmel, an invasive species specialist with Alberta Environment and Parks.

"Suspect it came into Alberta as a goldfish that was misidentified and potentially dumped."

It's still unclear how the species ended up in the nine-foot deep lake, but officials believe high water events may have led to a spillover.

The province says it currently has no plans to remove the fish.

"Even if we were able to remove it from Dodd’s Lake, there’s a good chance that it would probably be reintroduced," said Kimmel.

Kimmel says the carp have been found in many central and southern Alberta waterways over the last two decades and the introduction of a single fish can potentially interrupt an entire ecosystem.

"Prussian carp are really highly adaptable," explained Kimmel. "They can eat and accommodate some pretty unfavourable water conditions.

"Native fish probably can’t do that."

Carp typically reproduce quickly, spawning an average of three times per year.

The town is deferring the process to the province, but insists signs will be installed next year to remind residents that the species is in the lake.

"The plan is that we will put some signage in place, of course," said Ken Kowalchuk, a spokesperson for the Town of Innisfail. "We have a few months to work on that. Seeing as how we’re in the winter months, there’s probably going to be less traffic around the lake."

Kimmel says she has heard of people dining on, and enjoying, carp but adds it is a boney fish.

Anglers in Alberta are encouraged to kill all carp they catch.

"You do need a fishing license to angle just in case you catch any other fish," said Kimmel. "But we have exempted them from sport fishing guidelines so there is no limits. You can catch as many as you can. We encourage you, once you do catch it, to kill it and not return it to the waterbody."

It is illegal in Alberta to transfer any fish from one waterway to another and the offence can result in fines of up to $100,000 or a year in prison.

This Prussian carp was caught on Stockwell Lake, about 70 kilometers southeast of Rosetown. (Courtesy: Saskatchewan Sportfish Research Group)