In Alberta, schools of invasive goldfish, some as large as dinner plates, have become a widespread problem, prompting concern from the provincial government about the negative impact on native ecosystems. The Environment Minister, Grant Hunter, emphasized that goldfish should remain in aquariums and not be released into Alberta’s waters. The presence of goldfish has been identified in over 100 locations in the province, with new sites continuously being added each year, as confirmed by Alberta’s aquatic invasive species specialist, Nicole Kimmel.

Kimmel explained that the issue is not caused by accidental flushing but by deliberate dumping of goldfish into water bodies, where they thrive, overwinter, and reproduce. To address this problem, Alberta has launched the “Don’t Let It Loose” campaign to deter illegal species release into waterways, with penalties of up to $100,000 in fines and/or a year of imprisonment for offenders.

Goldfish pose significant risks to native aquatic ecosystems due to their adaptability and voracious feeding habits. Unlike many native fish species that have specific dietary preferences and reproduction habits, goldfish can survive harsh winters in Alberta and rapidly reproduce, with a single goldfish capable of producing up to 40,000 offspring within three years.

The issue of invasive goldfish extends beyond Alberta, with global implications. University of Toronto biology professor and invasive species expert, Nicholas Mandrak, highlighted the invasive nature of goldfish, noting their ability to thrive in extreme environments worldwide. Mandrak’s research in Ontario focuses on studying methods to prevent the spread of goldfish from storm-water management ponds into natural habitats.

Efforts to control goldfish populations involve chemical treatments or draining bodies of water when necessary, as established goldfish colonies are challenging to eradicate. Mandrak warned that if the illegal introduction of goldfish continues unchecked, the problem could escalate nationally, impacting native species diversity across the country.

Albertans are urged to report sightings of goldfish and other invasive fish to the Aquatic Invasive Species Hotline and to report any suspected intentional releases of aquatic invasive species to the Report A Poacher hotline for immediate action.