It may be winter but before we know it, we’re going to be seeing the first signs of spring. With beautiful buds comes the unfortunate reality of invasive plants. When it comes to these pesky species, knowledge is power to help stop the spread and protect native species. This year, Invasive Species Awareness Week (ISAW) is February 28 to March 4.
Six Frequently Asked Questions About Invasive Species
1. What are invasive species?
Invasive species are disruptors. They’re non-native species (plants, animals, fish, insects or even viruses and fungi) that have been introduced to an environment that have significant negative impacts on the surrounding ecosystem. They reproduce rapidly, can thrive in a wide range of habitats and have few natural predators to keep their populations in check. When left uncontrolled, invasive species displace native species, dominate habitats and can change the way natural areas function and the benefits they provide.
2. How did invasive species get here?
Invasive species can arrive at our doorstep in many different ways. The majority of introductions are due to human activity. For example, LDD moths were accidentally released by a naturalist who wanted to start a silk industry in North America. Some species were introduced deliberately for food or aesthetics, and others were brought to Ontario accidentally in the wood of shipping crates, in ballast water or as seeds in imported soil.
In 2020, we released our updated Invasive Species Strategy. The strategy outlines measures CVC is taking to respond to the issue of invasive species within the Credit River Watershed. As shown in this chart on Invasive Plant Species Pathways of Introduction, it is unknown how the majority of plant species were introduced to Canada. The Canadian Food Agency identified 11 ways that invasive plant species are introduced to Canada, with the largest percentage being 47 percent coming from unknown pathways.
3. Why should we care about invasive species?
There are over 184 invasive species in the Credit River Watershed. We find them in every single conservation area and throughout our communities. They have economic impacts costing Canadians millions of dollars each year. Invasive species can lower water levels, kill trees, degrade, impact sightlines, habitats and create fire hazards. They also crowd out native species such as mottled sculpin and logperch, and species at risk such as American ginseng
Phragmites is an example of an invasive species that can impact sightlines and create fire hazards. Dense stands not only block driver vision but also create thick mats of highly flammable, slow decaying thatch. Because they are often found along roadsides and in industrial areas, there have been serious fires that have spread long distances into natural areas and put local residents at risk.
4. What is the most common invasive species in the watershed and how is CVC addressing it?
Garlic mustard and European buckthorn are two of our most notorious invaders. Garlic mustard can often be found carpeting the forest floor where trout lilies and trilliums should abound. European buckthorn is a shrubby tree that forms thickets from forest to field. Both also love colonizing areas that have been disturbed by human activity, urban sprawl, and deforestation.
In the spring, our Habitat Restoration team heads out to pull garlic mustard in our conservation areas and work in partnership with municipalities to remove garlic mustard in municipal parks before it goes to seed. If you have ever pulled garlic mustard, you’ll know why our gloves smell of garlic all day! European buckthorn is pulled out by the root or cut down and stump treated so they do not resprout. Unfortunately, there’s always more of these species (and many others) than we have the time or resources to control.
5. What can you do to stop the introduction of invasive species?
There are a number of simple actions that you can take to prevent introducing invasive species to our watershed. These small actions can have a very big impact.
Don’t dump pets or bait.
Not only is it illegal but dumping bait buckets into the water is a common way aquatic invasive species like the round goby get into our waterways. Instead, put unused bait fish in the garbage (or the freezer) and empty bait water onto dry land well away from the shore.
Don’t release unwanted pets into natural areas. Goldfish and red-eared sliders are two invasive species commonly released by pet owners. They outcompete native species like the endangered spotted turtle.
Clean equipment and pets.
Make sure invasives aren’t hitching a ride with you! For example, garlic mustard produces thousands of tiny seeds that can get stuck on bike or ATV tire treads, the soles of your shoes or even your dog’s fur. If you’re in an area that has garlic mustard or other invasives, give your treads and your pet a brush before moving on to another area to keep seeds from spreading far and wide.
If you’re in the water clean, drain and dry your boat, paddleboard or waders before moving to a new waterbody. This prevents bringing nasty critters like zebra mussels or spiny waterfleas along with you.
|Clean, Drain||Clean, Drain, Dry||Clean, Drain, Disinfect|
|Clean off all visible mud, vegetation and other debris|
Pull and store the Drain plug, lower your outboard to drain live wells before leaving the launch
|In addition to cleaning and draining:|
Dry your boat and equipment in hot or sunny weather for 2-7 days before transporting them to another body of water.
|Use a pressure washer to spray off your boat and trailer (250psi) OR rinse off your boat and trailer with hot water (greater than 50 degrees C)|
To prevent the spread of viruses that infect fish, rinse live wells with 10% household bleach/water solution (i.e. 100ml of bleach to 1L water). Rinse well with water to remove any residual chlorine.
Credit: Ontario’s Invading Species Awareness Program.
Don’t move firewood.
Wood can harbour pests including emerald ash borer, LDD moth egg masses, and harmful fungi like Dutch elm disease and oak wilt. Many of these pests are microscopic and impossible to detect but can devastate an entire ecosystem if they get the chance. Source your firewood as close to where you’re burning it as possible. One hundred kilometres is too far. Fifteen kilometres or less is best.
Plant native species alternatives.
Did you know that many invasive plants such as periwinkle and goutweed are still available for sale in nurseries and garden centres? Unfortunately, these plants easily escape from gardens into natural areas where they can out compete native species such as ostrich ferns. Most native plants are hardy perennials that provide important food sources for pollinators and wildlife. Check out this Grow me instead guide for beautiful alternatives to invasive species. There are a number of nurseries in Southern Ontario that specialize in native species to help get you started.
6. What can I do to help stop the spread?
One of the biggest things you can do to help is by getting informed! If you are aware of invasive species and how they get around you can stop them from spreading to new areas and causing damage.
First, learn how to identify them. The next step is to check out your own backyard and remove invasives there. Always look into best management practices before starting to remove species to avoid making the problem worse. The Invasive Species Centre has many resources to help get you started.
Keep an eye out for CVC’s volunteer events. Come out and help us remove invasive species!
If you see an invasive species in the watershed, let us know through our online observation form.