Invasive Species

What Are Invasive Species?


Our ecosystems are home to three types of species: native, non-native, and invasive. Native species are those that naturally occur in an area. Over thousands of years, these species have formed symbiotic relationships with other species, like native bees pollinating native wildflowers. Non-native species are those that are not natural to an area and instead have been introduced due to human activity. Invasive species are a type of non-native species that have spread and pose a threat to native species because they compete with them for resources. In some instances, invasive species can almost completely take over an ecosystem. Dog-strangling vine, for example, is an invasive plant that quickly blankets forests, alvars, and other ecosystems. Phragmites (pictured left), or the ornamental grass you may have seen growing on roadsides, is another invasive species threatening native Ontario plants.

With globalization, invasive species are now found everywhere around the world and are a major threat to global biodiversity. While some of them, particularly with respect to plants, may appear beautiful and harmless, they are a major problem for our ecosystems, society, and economies. You can learn more about invasive species as well as how the Blue Lakes Program works with participants to monitor and control invasive species on their properties below!

Sources of Invasive Species

The one thing that the majority of invasive species introductions have in common is that they arrived due to human activity. There are a number of ways humans have introduced species to both terrestrial and aquatic ecosystems, but below are some common examples:

  • On cargo shipments from air, land, or sea
  • In boat ballast water
  • Through live food trade
  • Intentional release, typically during colonial times when settlers sought "familiarity" by introducing species from home
  • Release of unwanted exotic pets
  • Contaminated fishing gear
  • Introduction of non-native ornamental plants in gardens

Invasive Species: From Prevention to Control


Image courtesy of the Invasive Species Centre.

The figure to the left is known as the "invasion curve" and while it may look a bit complicated, the main message is that the longer we wait to deal with an invasive species, the more expensive it becomes. By far, preventing invasive species from entering our ecosystems is the most cost-effective way to deal with them, with a 1:100 economic return compared to substantially lower returns over time. Also note that beyond the eradication phase, we are often stuck living with invasive species (and their economic costs) in our ecosystems. For this reason, it's important to do your part in ensuring that invasive species do not make their way to your property and lake!

Invasive Species & The Blue Lakes Program

One of the Performance Areas that participants can set goals and actions under within the Blue Lakes Program surrounds invasive species management on their properties. Participants may elect to work under this Performance Area if their property or lake is currently invaded by invasive species, if there are invasive species nearby that are posing a threat, or even if they simply favour the aesthetic of native plants (like wildflowers) on their property. Example actions participants can take within Invasive Species Management Performance Area include:

  • Learning about local invasive species identification through webinars
  • Reporting 100 invasive species sightings each year through EDDMapS or iNaturalist
  • Decreasing the amount of space that is vulnerable to invasive species
  • Increasing boat washing
  • Removing and managing invasive species

Additional Resources

The Blue Lakes Program has put together fact sheets on invasive species in The Land Between as well as guides on native species that are often confused as weeds and additional resources. You can launch the guide below!

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