When staff with the City of Campbell River dispatched a team to remove what they believed to be several hundred invasive goldfish from a local pond, they were astonished to find 1,746 goldfish instead.
"It was quite shocking," said Steve Roehr, the City's operations' manager. "They multiply quickly and grow to be big – and that edges out native species.”
The invasive goldfish, measuring between 15 and 300 millimetres, were removed during the remediation efforts at the Erickson Stormwater Pond.
Goldfish are not native to North America, which is why the fish are classified as an invasive species when released into the wild. The fish are native to eastern Asia including China, Hong Kong, Japan, Korea, as well as some parts of Europe.
"Goldfish prey on native species or whatever fits in their mouth," Roehr explained. "It creates a lot of competition for the native species."
Goldfish also decrease water clarity with their feeding activity, reducing sunlight for underwater plants, which results in habitat loss for native species.
To remove the fish without harming the pond's ecosystem, the City hired an independent environmental contractor. The remediation process required extensive environmental permitting from the province, including one that allows the relocation of amphibians, such as salamanders and newts.
Throughout the eight-day procedure that involved continuously draining the pond, electro-fishing was employed to capture the goldfish. After that, the fish were chemically euthanized using an approved anesthetic, which killed them painlessly, Roehr said.
Based on their varying sizes and quantity, Roehr believes the fish had been in the pond for several years before they were discovered. They were initially reported in November 2023.
Roehr said he understands how people might have good intentions when releasing goldfish into the wild, but, he said, the environmental "consequences are just too great." Plus, remediation is a long and expensive process.
The work wrapped up on Oct. 18, and trails in the area are now open.
Residents and property owners are encouraged to learn more about what’s #notforthewild – and how to properly dispose of invasive species, both animals and plants, by visiting: www.campbellriver.ca/invasive-species.
