Goldfish derbies targeting invasive species in the city

By Justin Seward - Lethbridge Herald on July 19, 2022.

Herald photo by Justin Seward Aaron Moffat casts a line as son Jackson looks on during the Goldfish Fishing Derby at Firelight Pond on Saturday.

The City of Lethbridge hosted a Goldfish Fishing Derby at Firelight Pond for the public on Saturday.

The derby allowed the public to learn about the invasive species of goldfish in the city’s storm water ponds and attendees could cast a line in hopes of catching one to help lessen the population of the goldfish before a big treatment in the fall.

“Just to never release your aquarium species, whether they’re fish or plants or anything like that into our ponds,” said Jackie Cardinal, natural resources coordinator with the city’s parks department.

“They are really bad for our natural ecosystem and our water bodies do end up in our native rivers and streams. Anything that is released into a storm pond can potentially impact the river – so we don’t want anything released.”

Issues that arise include goldfish outcompeting the local native species and breeding multiple times a year.

“They outcompete for food, space and oxygen, so they impact our native fish species ” said Cardinal.

Cardinal said the population has grown quite a bit in the last five years.

Goldfish are not native to Canada or North America in general.

“The only way they can get in, is if people release them,” she said.

A full removal of the goldfish will commence at Firelight Pond in September and October with the use of Rotenon, which is a naturally occurring complex that is not hazardous to humans or pets and only to gill species.

“We’ll lower the pond down and treat it and then scoop the goldfish out,” she said.

The fish will then be transported to the landfill.

“We’re going to treat the pond twice to make sure that we catch anything that may have been in egg form when we first treat,” she said.

Firelight Pond, Chinook Lake and Elma Groves Pond are the three confirmed ponds in Lethbridge to have goldfish.

“Once we pull the fish out, I anticipate that the water quality will improve greatly,” she said.

The city will be back out in the spring to do netting and look for any unusual disruptions to the pond. The province did a study in 2020 and confirmed there were goldfish in the pond.

That started the process for the city to get their licensing and permits in order, and funding to treat the goldfish issue.

Another Goldfish Fishing Derby will be back on Aug. 13.