An invasive species is a plant, fungus, or animal species that is not native to a specific location (an introduced species), and which has a tendency to spread to a degree believed to cause damage to the environment, human economy or human health.
There are a number of invasive species that have made Saskatchewan their new home. They pose a serious threat to the country’s native species and habitat. They’re also the second most common threat when it comes to species extinctions, habitat loss being number one.
"Invasive Species aren't from here and they can rapidly repopulate themselves," said Matthew Braun, Manager of Conservation Science and Planning, with Nature Conservancy of Canada's Saskatchewan Region. "They move into an area where they don't have any natural predators, nothing to keep it in check. Something like leafy spurge has no animals to eat it and no bugs to keep it under control. So it expands rapidly, which means that other plants that would normaly grow there can't grow anymore. So the cows, deer, elks and moose that would normally eat there have less and less to eat because they can't eat the leafy spurge that grows there. So it damages our ecosystems that we've come to depend on for our livelihood and survival as well."
The invasive plants in Saskatchewan are generally from Europe. The plants can move into our land either through hay from different areas or from ornamentals being brought into local garden centers.
Most well-known invasive plants in Saskatchewan
Knapweeds: There are five invasive knapweed species in Canada that were unintentionally introduced into Canada from Europe in the late 1800s, probably in alfalfa and clover seeds. All species have slender stems with purple (or sometimes white) flowers and grow from a deep taproot. Spotted knapweed is an aggressive invader that is especially problematic in native grasslands in western Canada.
Photo of common tansy courtesy of Chet Neufeld, Executive Director for the Native Plant Society of Saskatchewan.
Common tansy: Common tansy is native to Europe and was introduced to North America in the 1600s as a horticultural and medicinal plant. It has yellow, button-like flowers and can grow to 1.5 metres in height. It has been documented from every region in Canada except Nunavut, but is having the greatest impact on stream banks and native grasslands in the prairies and central BC. In addition to outcompeting native plants, common tansy produces a toxic compound that can impact cattle and wildlife.
Photo of purple loosestrife courtesy of Chet Neufeld, Executive Director for the Native Plant Society of Saskatchewan.
Purple loosestrife: Identified by the International Union for Conservation of Nature as one of the world’s worst invading species, a single purple loosestrife plant can produce over 2 million seeds each year! This species was introduced to North America from Europe in the 1800s for ornamental and medicinal purposes. In fact, it is still sold as an ornamental plant in some places. Purple loosestrife crowds out most native vegetation and can create near-monocultures. From 1992 to 1994, two beetles and two weevils from Europe were released as a biological control and seem to be reducing the numbers of this plant.
Photo of baby's breath courtesy of Chet Neufeld, Executive Director for the Native Plant Society of Saskatchewan.
Baby’s breath: This is a herbaceous perennial plant that invades grazing land and out-competes native and introduced perennial grasses. Plants flourish in the well-drained sandy or gravelly soils of vacant lots and along fencelines, establishing unsightly infestations. Baby's breath that mixes with hay reduces the protein value of the crop, making it less valuable for livestock and wildlife forage. Though considered unsightly as an escape ornamental, the delicate white or pink blooms and bushy stalks of baby's breath are used extensively in the floral industry for dried and fresh flower arrangements. Seeds often continue to develop in floral arrangements, allowing easy spread. A single plant can produce more than 10,000 seeds that can travel long distances when a complete stalk rolls freely like a tumbleweed.
The economic cost, nationally, from invasive species is anywhere from $16 to $34 billion dollars a year because of its impact on Canada’s biodiversity. Braun said the cost is also high because of loss of productivity, constantly having to treat the plants and the toxicity can make people and live stock sick meaning there would be medical costs associated with that.
Currently one of the worst invasive species in Saskatchewan is the zebra mussel. They'll clog up water pipes, which is expensive to maintain and it can cut off residents' only source of clean water.
You can help stop the spread by remembering to practice: CLEAN, DRAIN, DRY
Before returning home from out of province, coming to visit or moving between waters within the province – please follow these important steps to help protect Saskatchewan waters.
- CLEAN and inspect the watercraft, trailer, equipment and all gear that made contact with the water.
Remove all visible plants, animals and mud. Scrub/scrape grainy surfaces that feel like sandpaper, as this could be young mussels too small to see.
Wash, scrub or rinse using high pressure, hot tap water away from storm drains, ditches and waterways.
Inspect the watercraft, trailer and vehicle.
- DRAIN all on-board water from the motor, livewell, bilge, and ballast tanks. Flush with hot tap water away from storm drains, ditches and waterways. Then leave plugs out during transport and storage.
- DRY your watercraft, equipment and all related gear completely, preferably for at least five days while leaving compartments open to dry.
And remember to DISPOSE of all unwanted bait in the trash. Never release leftover leeches or crayfish, aquarium pets, plants or water into our lakes, rivers or wetlands.
To fight the invasion of all of these dangerous invasive species, residents can ask their local garden center if certain plants are considered invasive or they can report any invasive plants that they find to the Saskatchewan Invasive Species Council by clicking here.
If enough people work together, these species can be greatly reduced, maybe even one day eliminated.