The Ontario government has designated 10 species and four groups of similar species as invasive under the Ontario Invasive Species Act. These regulations aim to prevent, control, and reduce the spread of these species within Ontario. The designated species fall into two categories: Prohibited and Restricted. Prohibited species cannot be imported, possessed, released, transported, propagated, bought, sold, leased, or traded. Restricted species cannot be deposited or released in Ontario and are not allowed in provincial parks or conservation reserves.
The prohibited species include 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 restricted species include Eurasian Water-milfoil (aquatic plant), Floating Primrose-willow (aquatic plant), Flowering-rush (aquatic plant), Tree-of-heaven (terrestrial plant), and Genus Azolla (Water Ferns – aquatic plant).
These invasive species pose various potential impacts, such as introducing parasites, virus and disease transmission, competing with native fish species for food and habitat, reducing native fish populations through predation and genetic impacts, adversely affecting water quality, impeding recreational activities, impacting agricultural areas and increasing flooding risks, spreading parasites and diseases to humans, pets, and livestock, destroying coastal wetlands, and displacing native vegetation. The government's actions aim to protect the environment and economy by addressing the threats posed by these invasive species. Effective January 1, 2024, the regulations will take effect, prohibiting the listed species and imposing restrictions on others.