Invasive Species: A Threat to Ontario's Biodiversity

Sea lamprey
Sea lamprey - Photo: John Lyons/Wisconsin DNR.

Invasive species are a serious threat to Ontario’s biodiversity and can damage native species.


Invasive species destroy habitat, disrupt food webs, and can cause the introduction of parasites and disease.


What are invasive species?


What can you do?


What is Ontario doing?

Zebra mussels encrust bumper

Zebra mussels coating buoy

Photo: Dave Britton/US FWS


Invasive species come from other countries or regions and are called "exotic" or "alien" when they move outside their native habitat.


Not all exotic species are harmful. But those that threaten our environment, economy or society by disrupting local ecosystems are known as "invasive species."



Emerald ash borer and Larva

Emerald ash borer and larva

Photo: Taylor Scarr/MNR


Most invasive species are introduced by human activities. That’s why each of us has a part to play in preventing and controlling them.


Here’s a list of things you can do to help fight invasive species.


Dog strangling vine

Dog strangling vine

Photo: Greg Bales/MNR


The Government of Ontario and its partners are taking action to prevent, control,

and monitor invasive species.


Learn more about our projects and activities.

Learn about:

Report sightings of invasive species


Aquatic invasive



Terrestrial invasive species

Giant hogweed

Giant hogweed

Photo: Karen Rimmer


Rusty crayfish

Rusty crayfish - Photo: Bev Wigney



Phragmites  - Photo: Janice Gilbert/MNR