As of January 1, 2024, we have regulated 10 additional invasive species and 4 groups (genus) of species (marked "new") under the Invasive Species Act.

Provincial rules

The Invasive Species Act sets out regulations to prevent and control the spread of invasive species.

Species regulated under the act pose a risk to Ontario’s natural environment. We assess a species’ risk by looking at its biological characteristics, risk of harm to the natural environment, ability to disperse and social and economic impacts.

There are two classes of invasive species regulated under the act: prohibited and restricted.

Prohibited invasive species

It is illegal to import, possess, deposit, release, transport, breed/grow, buy, sell, lease or trade prohibited invasive species.

Fish

Insects

Aquatic invertebrates

Plants

Mammals

Exceptions for prohibited species

  • Dead and eviscerated (gutted) bighead, black, grass or silver carp, Prussian carp, tench, zander or snakeheads may be imported, transported, bought or sold in Ontario.
  • Red swamp crayfish, white river crayfish and signal crayfish which are dead and prepared for human consumption (for example, cooked) may be imported, transported, bought or sold in Ontario.
  • If you happen to catch a prohibited invasive fish, invertebrate or plant species while fishing, you must immediately destroy it so it cannot reproduce or grow. Do not release invasive species back into the water.
  • If you are boating in a body of water where European water chestnut or water soldier are found, try to avoid the infested area. You must also:
    • avoid spreading these plants
    • remove the plants from your boat, motor and trailer before travelling over land
    • dispose of the plants so they won’t end up back in the water

Transition period for regulated species

If you possessed red shiner or crayfish in the Procambarus genus or Pacifastacus genus on January 1, 2024, the date the relevant changes to Ontario Regulation 354/16 came into force, you may continue to possess and transport them until January 1, 2026. This transition period does not apply to marbled crayfish and red swamp crayfish which were both regulated as prohibited invasive species on January 1, 2022.

The transition period provides time to become aware of the rules and dispose of the organisms. You must kill the organisms and dispose them in a way that ensures they do not spread (for example, frozen and in the garbage) prior to January 1, 2026.

If you would like to learn more about what you need to do during this transition period, please contact us at invasive.species@ontario.ca.

Restricted invasive species

In Ontario, it is illegal to import, deposit, release, breed/grow, buy, sell, lease or trade restricted invasive species.

Plants

It is also illegal to bring these plants into provincial parks and conservation reserves and to possess, transport, deposit or release them in these protected areas.

Mammals

Exceptions for restricted species

Outside a provincial park or conservation reserve, it is not illegal to deposit or release a restricted species if you are:

  • trying to manage or control it
  • working on your farm, in your business or doing maintenance

If you deposit or release a restricted invasive species while undertaking any activity listed above, you must take reasonable precautions to prevent the spread of the restricted invasive species outside the immediate area where the activity is taking place.

Preserved Specimens

You can preserve a specimen of a prohibited or restricted species (for example, for scientific or educational use) as long as it is dead and preserved using a method:

  • other than refrigeration or freezing
  • that prevents it from reproducing

Authorization under the Invasive Species Act

If you undertake certain activities for research or education, or for the prevention, control or eradication of a regulated invasive species, you will either:

  • require an authorization under the Invasive Species Act; or must
  • adhere to conditions specified in a prevention and response plan

The ministry has completed prevention and response plans for European Water Chestnut (PDF) and Water Soldier (PDF). If you have questions about the need for an authorization under the Invasive Species Act, please contact invasive.species@ontario.ca.

Federal rules

Federal regulations under the Fisheries Act include rules for Ontario's invasive fish and aquatic species throughout Canada.

Under the federal rules, in Ontario it is illegal to:

  • import, possess, transport or release bighead carp, black carp, grass carp, silver carp and snakeheads unless they are dead and eviscerated (gutted)
  • possess, transport or release round goby, tubenose goby, rudd or ruffe unless they are dead

It is illegal to possess or use any of these fish as bait, even if they are dead.

It is also illegal to:

  • bring zebra or quagga mussels into Canada
  • introduce aquatic species to areas where not naturally found

Fishing with live bait

To catch and fish with certain types of live bait already found in Ontario waters, you need:

  • the proper fishing licence
  • to follow the rules for fishing with live bait, including where you can do it and how much you can catch

Contact us

If you have a question about invasive species in Ontario, call the Natural Resources Information Support Centre at Toll-free: 1-800-387-7011 or Toll-free: 1-800-387-7011, or email us at: NRISC@ontario.ca.