Managing invasive species in Ontario
Invasive species affect us all. Learn about Ontario’s rules to help stop the spread and protect our natural environment.
Provincial rules
In Ontario, the Invasive Species Act sets out rules 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.
Species group
Exceptions for prohibited species
- Dead and eviscerated (gutted) bighead, black, grass or silver carp, zander or snakeheads 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 can’t reproduce or grow. Do not release invasive species back into the water.
- If you’re 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
Restricted invasive species
In Ontario, it is illegal to import, deposit, release, breed/grow, buy, sell, lease or trade restricted invasive species.
Species group
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.
Exceptions for restricted species
Outside a provincial park or conservation reserve, it's 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
You can preserve a specimen of a prohibited or restricted species (for example, for scientific or educational use) as long as it's 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 of Natural Resources and Forestry (MNRF) 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’s 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's 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
It's illegal to:
- empty your bait bucket in or within 30 metres of a body of water, including on the ice
- bring any crayfish, salamanders, live fish or live leeches into Ontario for use as bait
Contact us
If you have a question about invasive species in Ontario, call the Natural Resources Information Support Centre at
