They're baaaack: Goldfish spotted in Okotoks storm ponds once again

Goldfish are prevailing in the Town of Okotoks's storm water systems, despite officials' best efforts to rid the ponds of the invasive species.

Town spent lots of time and money last year trying to remove invasive species

A large goldfish pulled out of a stormwater pond in Okotoks in 2016. (Terri Trembath/CBC)

Goldfish are again swimming in the Okotoks's storm water systems, despite the best efforts of officials to rid the ponds in this community south of Calgary of the invasive species.

Last summer, Okotoks spent a lot of time and money trying to purge the waterways of the fish. Christa Michailuck, the town's parks manager, says with the help of Alberta Environment, they twice treated the two affected ponds with a plant-based fish toxin.

"We had thousands of fish come up in each of the first treatments at the two ponds and then just a handful of fish come up in the second treatments, so we were quite optimistic and hopeful that we had achieved eradication," Michailuck told the Calgary Eyeopener.

Despite the treatments and a long, cold winter, goldfish have once again been spotted in the storm water ponds.


The town believes the fish must have come from a resident's fish tank or pond — someone releasing them in order to dispose of them. Michailuck says they aren't sure if the fish spotted this year are survivors left over from last year, or a whole new crop. 

It's also likely the fish could have come from another one of the town's 14 storm water ponds, some of which are interconnected.

The town's next step is to inventory the problem further. Michailuck says they will be testing all of the ponds for fish DNA to see how prevalent the problem is.

"We're hopeful we can control the goldfish before they get to be such a problem throughout water systems in Alberta," she said.

With files from the Calgary Eyeopener