28-05-2025
Pet owners urged to avoid dumping goldfish in Ontario ponds and other waterways
Goldfish seen in a retention pond off the Spurline Trail in Waterloo Region in May 2025. (Courtesy: Harvey McLaren)
Officials are asking pet owners to find new homes for unwanted goldfish after they were spotted swimming in ponds in both Kitchener, Ont. and Waterloo, Ont.
'Generally, people from the public put goldfish into stormwater management ponds, thinking they're doing them a favour by releasing them into the 'wild',' explained Jessica Kellerman, the director of stormwater management and construction with the City of Waterloo. 'It's actually not doing them a favour because they are an invasive species.'
Neighbours said they've seen an 'explosion' of goldfish in a retention pond off Spurline Trail, including some koi fish, so far this year.
goldfish spurline tail waterloo region water
Goldfish seen in a retention pond off the Spurline Trail in Waterloo Region in May 2025. (Courtesy: Harvey McLaren)
'We know those fish do not belong there,' goldfish farmer Andrew Bridgemohan said.
He owns The Fish Sempai, a goldfish and koi farm in Breslau, Ont. He said some goldfish carry a disease known as spring viraemia of carp (SVC), a contagious and potentially fatal disease affecting freshwater fish.
Goldfish can also kill off the surrounding ecosystem.
'It can overtake the lake, which you don't want,' Bridgemohan said. 'And they can multiply really fast.'
Another problem is they can bring uninvited guests out of their natural habitat.
'It's going to start attracting more wildlife into that area because it's a food source, especially for a species such as a raccoon,' said Bill Dowd, founder of Skedaddle Humane Wildlife Control.
According to Kellerman, when goldfish are dumped in stormwater management ponds, they end up wreaking havoc on city facilities and resources.
'It can create more of a cost for the city, in terms of having to go in and fish out goldfish because they are creating turbidity issues within the facilities,' she said. 'If there are too many goldfish in there, it can create issues with settlement of the material and it can lead to like malfunction of the facility in terms of the material that's moving through.'
goldfish spurline tail waterloo region water
Goldfish seen in a retention pond off the Spurline Trail in Waterloo Region in May 2025. (Courtesy: Harvey McLaren)
For those looking to get rid of their goldfish, experts recommend rehoming or reaching out to their local pet store.
'Before you buy, think twice,' Bridgemohan said. 'It takes a lot of work. I would not say it's easy.'
