Invasive Species

SSEA​’s Invasive Species Program involves working with our partners to prevent, detect, monitor and manage invasive species in the Severn Sound area.

We work towards coordinating efforts of municipalities, community associations and the public to effectively manage invasive species.

Spongy Moth Larvae - SSEA
Spongy Moth Larvae
SSEA Purple Loosestrife - Invasive Species
Invasive Purple Loosestrife

Aliens among u​s

Alien species are plants, animals, invertebrates, and micro-organisms accidentally or deliberately introduced outside of their natural past or present distribution. Invasive alien species (invasive species) are those harmful alien species whose introduction or spread threatens the environment, the economy, or society, including human health. Invasive species are a serious problem and have a variety of negative impacts including changing ecosystems. The Invasive Species Centre estimates the potential economic impacts of invasive species on forestry, agriculture, fisheries, healthcare, tourism and recreation to be approximately $3.6 billion per year in Ontario.

SSEA Black Locust - Invasive Species
Invasive Black Locust
SSEA Mystery Snail - Invasive Species
Banded Mystery Snail

Typically, an alien species becomes invasive because of a lack of natural controls (e.g., predators or disease) that would be present in their home range to keep the population in check. Without these natural controls, invasive species have a competitive edge over native species, and become a problem through rapid spread and increase in numbers.

Invasion of a species can occur by accidental or purposeful introduction. Some examples of unintentional introduction of invasive species include: weed seeds mixed in with imported soil or crop seeds, and insects, disease or fungus that hitchhike on imported materials. In other cases, invasive species can be intentionally introduced as agricultural crops, landscape plants, ornamentals, or plants for medicine and research.

The problem of invasive species is complex – there are lots of species, many different pathways for them to become established, and they can’t all be controlled in the same way.

How YOU Can Help

What is an Invasive Species Flow Chart
An invasive alien species is introduced outside its natural past or present distribution AND threatens the environment, economy, society, and/or human health.
  • Learn to identify invasive species and share your knowledge with members of your community. Apps such as iNaturalist can help you identify and record native and invasive species observations.
  • Report sightings of invasive species in the SSEA area to, to or call the Invading Species Hotline at 1-800-563-7711. These reported sightings help with detection, monitoring and management – rapid response to new invaders is important for effective management.
  • Take action to reduce impacts of invasive species on your property and participate in local invasive species control/management activities.
  • Remove and dispose of invasive species properly according to the Best Management Practices (BMPs). Specific BMPs are linked in the species descriptions below.
    • For the removal of noxious weeds on your property, you may require assistance from an Invasive Plant Management Professional. 
  • Prevention is crucial – eradication is costly and challenging once invasion occurs.
    • Do not dump yard waste or garden plants in the wild. Yard waste can contain non-native invasive microorganisms, plants, seeds, eggs and insects. Non-native invasive species can be unintentionally introduced to a natural area by improper disposal of ​garden material. Invasive plants tend to be more competitive and overtake natural areas, inhibiting native plant growth. Invasive plants can even grow from small fragments! You can help prevent the spread of invasive species by disposing of yard waste through your local municipality – home composting of non-native species may not effectively kill the plant.
    • Stay up-to-date on laws regarding invasive species. In the Province of Ontario, it is illegal to import, deposit, release, ​breed/grow, buy, sell, lease or trade restricted invasive species.
    • Follow Best Management Practices for gardening:​​
  • Follow SSEA on Instagram and Twitter to stay updated about invasive species management in the Severn Sound area.
  • Learn more about invasive species on the SSEA’s YouTube channel.
  • Contact SSEA with invasive spec​i​es questions or to report local sightings:

Learn more


Invasive Species Factsheets​​​

SSEA Invasive Species Working Gr​oup Minutes

​​​SSEA Invasive Species Reports

Invasive Species

Invasive Plants/Algae

Chinese/Common privet (Ligustrum vulgare)

Climbing/Bittersweet Nightshade (Solanum dulcamara)

Common Reed (Phragmites australis ssp. australis) – see Phragmites

Common St. Johnswort/ Goatweed (Hypericum perforatum)

Didymo / Rock Snot (Didymosphenia geminata)

• Michigan Invasive Species

Phragmites/ Common Reed (Phragmites australis ssp. australis)

Pink Jewelweed (Impatiens glandulifera) – see Himalayan Balsam

Policeman’s Helmet (Impatiens glandulifera) – see Himalayan Balsam

Rock Snot (Didymosphenia geminata) – see Didymo

Invasive Animals/Microorganisms

Bighead Carp (Hypophthalmichthys nobilis) – see Asian Carps

Black Carp (Mylopharyngodon piceus) – see Asian Carps

Grass Carp (Ctenopharyngodon idella) – see Asian Carps

Silver Carp (Hypophthalmichthys molitrix) – see Asian Carps

Also see Invasive Snails below.

Channeled Apple Snail (Pomacea canaliculata) – see Invasive Snails

Chinese Mystery Snail (Cipangopaludina chinensis/ Bellamya chinensis)

Fishhook Waterflea (Cercopagis pengoi) – see Spiny Waterflea & Fishhook Waterflea

Japanese Mystery Snail (Cipangopaludina japonica) – see Invasive Snails

Mystery Snail – see Invasive Snails

New Zealand Mud Snail (Potamopyrgus antipodarum) – see Invasive Snails

Quagga Mussels (Dreissena bugensis) – see Zebra Mussels & Quagga Mussels

​Spotted Lanternfly (Lycorma delicatula)

Report unusual bat activity (e.g., flying outside in the daytime) or deaths to the Canadian Cooperative Wildlife Health Centre (1-866-673-4781) or the Natural Resources Information Centre (1-800-667-1940 TTY for the hearing impaired at 1-866-686-6072).

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