Do Not Release Live Fish in Ponds/Lakes
Posted on 04/07/2022
goldfish in lily pond

Once released into public waterways goldfish are considered an invasive species.

The ecology and impacts of Goldfish introduced to North America's waters have not been widely studied. However, the behaviour of Ontario populations indicates they may reduce the province's biodiversity through their effects on native species.

  • Goldfish eat snails, small insects, fish eggs, and juvenile fish, making this species a competitor with, and predator or, native fish.
  • They stir up mud and other matter when they feed, which increases the cloudiness of water and affects the growth of aquatic plants.
  • They have the potential to produce large populations in some situations, especially in stagnant water with few predators.
  • Goldfish carry diseases, such as Koi herpesvirus that can harm local fish populations.

Please do not release any live fish into Ontario lakes, rivers or streams. Return or donate unwanted aquarium fish to a pet store or local school