Intruders in Muskoka: Invasive Species

2018 Muskoka Watershed Report Card Logo


The 2018 Muskoka Watershed Report Card produced by the Muskoka Watershed Council features 8 different indicators of watershed health. Invasive Species are one of these indicators, categorized as a threat indicator rather than a health indicator.


Invasive species are defined as plants, animals and micro-organisms that out-compete native species for habitat and resources when introduced outside of their natural past or present distribution. Their presence poses a threat to local ecosystems, but also to the economy as invasive species tend to cause a lot of irreparable damage to our goods and services.


The Ministry of Natural Resources and Forestry (MNRF) has identified 24 invasive species in Ontario, 7 of which are found in the Muskoka Watershed. These species are so successful because they have few natural predators, they thrive in disturbed ecosystems where other species do not, they are able to outcompete for food and habitat, they are adaptable, and they reproduce quickly. Due to these qualities, it is difficult to eradicate them. While there are some measures that can be taken once a species has established itself, the key is to prevent them from establishing in the first place.


Unfortunately, some of the popular activities in Muskoka such as boating, fishing, ATVing, and hiking heighten the risk of introducing invasive species to the Muskoka Watershed. Additionally, with increased tourist traffic into Muskoka this risk is heightened as well. The best defense against these intruders is knowledge. Knowing how to identify an invasive species, prevent transfer of invasive species and how to report them can help us to keep these unwanted visitors out of our communities!


Check out how your subwatershed ranks for invasive species and learn what you can do to help by visiting the 2018 Muskoka Watershed Report Card website at


2018 Report Card Invasive Species Infographic