New Species Added to the Ontario Invasive Species Act

The Ontario government is regulating 10 species and four groups of similar species under the Ontario Invasive Species Act (ISA) to help prevent, control and reduce their spread within Ontario.

There are two classes of invasive species regulated under the ISA: Prohibited and Restricted. For prohibited species, it is illegal to import, possess, deposit, release, transport, propagate (breed/grow), buy, sell, lease or trade these invasive species. For restricted species, it is illegal to deposit or release restricted invasive species in Ontario and cannot be brought into a provincial park or conservation reserve.

The following species and groups will be prohibited in Ontario effective January 1, 2024:

  • Ide (fish)
  • Eastern and Western Mosquito Fishes (fish)
  • Red Shiner (fish)
  • Oxygen Weed (aquatic plant)
  • Nutria (mammal)
  • Genus Salvinia (Watermoss – aquatic plant)
  • Genus Procambarus and Genus Pacifastacus (Crayfish)

The following species and group will be restricted effective January 1, 2024:

  • Eurasian Water-milfoil (aquatic plant)
  • Floating Primrose-willow (aquatic plant)
  • Flowering-rush (aquatic plant)
  • Tree-of-heaven (terrestrial plant)
  • Genus Azolla (Water Ferns – aquatic plant)