Invasive alien species


What is an invasive alien species?

“An exotic species whose introduction or spread threatens the environment, the economy or the  society, including human health. It may originate from another continent, neighboring countries, or even from another ecosystem in Canada itself.”[1]

The consequences

Invasive alien species pose a serious threat to biodiversity, since in a new ecosystem they become predators, competitors or parasites of native and domesticated species, or will even hybridize with native species. What’s more, the introduction of an invasive alien species is often irreversible[1].

As a result, their consequences are not limited to the environment, but also to the economy and society.

The economic consequences are linked to the costs and resources required to manage and control these species to avoid negative repercussions on property values, forestry, agricultural and aquaculture productivity. While societal impacts can directly affect human health in addition to hindering the practice of certain recreational activities. [2]

Many species have already been introduced into Canada and Quebec

Asian ladybug (Harmonia axyridis)
Mute swan (Cygnus olor)
Japanese knotweed (Reynoutria japonica)
Common reed (Phragmites australis subsp. australis)

Need help identifying different invasive alien species

You can consult the Quebec government’s Sentinelle website, where you can view their description and report their presence.

The following links provide more information on invasive alien species, on what to do about them and how to report their presence.

Invasive alien species :

Good practices :

Signal :

Service concerned

The free Green Line service can help if you have questions about invasive alien species and need assistance.

Telephone: 514-684-3114

E-mail :

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