Invasive species

Invasive species are often spread unknowingly. As an angler or boater, you should always take precautions to help stop invasive species. Ontario’s Invasive Species Act, 2015 regulates activities to prevent the introduction and spread of species that negatively affect Ontario’s biodiversity and/or economy. Federal regulations also prohibit the introduction of all aquatic species to an area where they are not naturally found.

For more information on invasive species in Ontario, visit To report a sighting call the Invading Species Hotline 1-800-563-7711 or visit

Prohibited invasive species

In Ontario, it’s illegal to import, possess, deposit, release, transport, breed, grow, buy, sell, lease or trade these species.


  • bighead carp
  • black carp
  • grass carp
  • Prussian carp
  • silver carp
  • snakeheads (all species in the snakehead family)
  • stone moroko
  • tench
  • wels catfish
  • zander


  • common yabby (a crayfish)
  • golden mussel
  • killer shrimp
  • marbled crayfish
  • New Zealand mud snail
  • red swamp crayfish


  • Brazilian elodea (Brazilian waterweed)
  • European water chestnut
  • hydrilla
  • parrot feather
  • water soldier

Additionally, it’s against the law to possess, transport or release live round goby, tubenose goby, rudd or ruffe in Ontario or to import zebra or quagga mussels into Canada.

Restricted invasive species

In Ontario, the following aquatic plant species are illegal to import, breed, grow, buy, sell, lease or trade, or to possess or transport within a provincial park or conservation reserve:

  • European Frog-bit
  • Carolina Fanwort
  • yellow floating heart
  • phragmites

Sale of prohibited invasive species

Only the following prohibited invasive species may be imported, possessed, transported, bought or sold:

  • dead and eviscerated (gutted) bighead carp, black carp, grass carp, Prussian carp, silver carp, tench, zander or snakeheads
  • dead red swamp crayfish that have been prepared for human consumption (such as cooked)

Boating rules

It is illegal to transport watercraft and watercraft equipment (any thing that is used to aid in the operation, movement or navigation of a watercraft including ropes, fenders or anchors) overland unless:

  • drain plugs or other devices used to control drainage have been removed or opened to allow water to drain out
  • reasonable measures have been taken to remove any aquatic plants, animals, or algae from the watercraft, watercraft equipment, vehicle, and trailer

Persons who move watercraft or watercraft equipment overland must additionally ensure that prior to arriving at a launch site or placing a watercraft in any body of water, the watercraft, watercraft equipment, vehicle, and trailer are free of all aquatic plants, animals, and algae.

In addition to the rules above, if you are boating in waterbodies where European water chestnut or water soldier plants exist, you must:

  • take reasonable precautions to prevent transport and deposit of plants outside the infested area to other parts of the waterbody (such as avoid boating through the infested area if you can)
  • dispose of these plants so they don’t end up back in any waterbody

In general, avoid running boats through aquatic plants as propellers can break aquatic plants loose and spread invasive species.


If you happen to catch a prohibited fish, invertebrate or plant, you must immediately destroy it in a way that ensures it cannot reproduce or grow.

Round goby

Round goby have become widely established in Southern Ontario and Lake Huron and have negative impacts on native fish. It is illegal to use gobies as bait or have live gobies in your possession. Anglers should know how to identify round goby since these aggressive fish are easily caught by hook and line. If you catch a round goby (or any invasive species) it should be destroyed as it cannot be released live into any waters. Report any new sightings.

A Round Goby’s key identification features are its frog-like eyes, black spot on dorsal fin and suction-cup like pelvic fin.

Credit: Donna Francis

Help slow the spread of Viral Hemorrhagic Septicemia (VHS)

VHS is an infectious disease of fish that has been documented in Ontario. Infected fish may show some of the following signs:

  • pale gills and organs
  • bloated abdomen
  • bulging eyes
  • bleeding of the body and organs
  • a darker body colour

VHS is not a threat to human health. Fish carrying the VHS virus are safe to eat and handle.

More information is available at Viral Hemorrhagic Septicemia or call the Natural Resources Information and Support Centre at 1-800-387-7011.