Residents who can no longer care for a pet goldfish are being asked to find it another home—not release it into Chestermere Lake, a storm pond or any other waterway.
The City of Chestermere says an aquarium fish may appear harmless, but goldfish released outdoors can survive, reproduce and compete with native species. Their feeding activity can disturb sediment, reduce water clarity and damage aquatic habitat.
Alberta Environment and Protected Areas identifies goldfish and koi as non-native ornamental fish capable of causing significant harm when introduced into natural systems. The province says goldfish are known at more than 100 Alberta locations, primarily urban stormwater ponds.
Their ability to live through Alberta winters is no longer in doubt. Provincial information says established populations have been found as far north as Fort McMurray. In open water, the fish can grow far beyond the size commonly seen in household aquariums.
No information released with Chestermere’s reminder indicates that goldfish have become established in Chestermere Lake or a local storm pond. The message is preventative: once an invasive population takes hold, removing it can be difficult, expensive and disruptive to the waterbody.
Releasing aquarium animals, plants or water into lakes, rivers, ponds and storm sewers is illegal. Alberta’s guidance warns that aquarium contents may also carry diseases or parasites capable of affecting native species.
Residents unable to keep a fish can ask a pet retailer about surrender options, find another aquarium or pond owner, contact an aquarium society or consult a veterinarian about humane disposal. Fish should not be flushed down a toilet.
Suspected aquatic invasive fish can be reported to Alberta’s hotline at 1-855-336-BOAT (2628).
For a city built around its lake, prevention begins with a simple household decision: aquarium pets belong in managed care, not in the waterways shared by the wider community.