Have you ever noticed an unfamiliar plant taking over your garden or spotted those tall, leafy stalks growing along the riverside?
If you live in Squamish or anywhere along the Sea to Sky Corridor, you’ve likely encountered invasive species, even if you didn’t realize it.
These unwelcome guests alter our local landscapes, threaten ecosystems, and even impact how folks farm.
However, efforts to manage these invasive species are being made by groups like the Sea to Sky Invasive Species Council (SSISC), the Sḵwx̱wú7mesh Úxwumixw (Squamish Nation), and local volunteers.
Knotweed–growing concern in the Sea to Sky region
Among the most troublesome invasive plants in the region are knotweed species.
“One species of concern for us is knotweed. There are a few types, but they’re often lumped together because of their similar impacts,” said Claude-Anne (Clo) Godbout-Gauthier, communications and outreach manager for SSISC in an interview to The Squamish Chief.
“They’re a major concern mainly around Squamish and further south. These plants grow very quickly and form dense clumps, or monocultures, which crowd out other plants and shade them out.”
The consequences don’t stop there.
“Their roots can make soil more prone to erosion, and since they like to grow near water, erosion can become a serious issue during major rain events,” she said.
Incorporating Indigenous knowledge in managing invasives
Managing invasive species in the Sea to Sky region has greatly improved through the partnership between the Sea to Sky Invasive Species Council (SSISC) and the Nation.
This collaboration follows a "two-eyed seeing" approach, which blends Indigenous knowledge with Western science to better care for the land, Godbout-Gauthier.
“We’ve worked with the Squamish Nation for years to manage invasive species on reserve lands,” she said.
“Together, we decide which species and areas our crews should focus on during the summer.”
“We are always learning from our Indigenous partners, like the Squamish Nation, about their deep connection to the land and the importance of culturally significant species,” she said.
She also pointed out how serious the issue is.
“Our Indigenous partners recognize the serious threat that invasive species pose—not just to people and infrastructure, but to the environment and culturally vital species as well.”
Invasives threaten more than just plants
Invasive species don’t just harm plant life.
According to Godbout-Gauthier, knotweed can also negatively impact fish populations and water quality, posing a significant threat to the region’s waterways.
“These plants also pose potential problems for infrastructure,” she said.
One-way locals are getting involved in the fight against invasives is through community-led initiatives like the "Crab Team," a group of volunteers who monitor the Squamish section of Howe Sound and the Squamish River Estuary for invasive European green crabs.
"While reporting sightings is easy for plant species (i.e., simply taking a picture on a smartphone), green crab monitoring follows a more thorough protocol and the volunteers receive formal training," said Godbout-Gauthier in an email to The Squamish Chief.
These crabs have the potential to disrupt eelgrass beds, which are critical habitats for local marine life, including young salmon reads the website.
"We affectionately call it the 'Crab Team'," said Godbout-Gauthier.
"The goal is to monitor our area, and community members can contribute to scientists’ understanding of species distribution by submitting what they observe. It’s really as easy as taking a picture with your smartphone, filling out a quick form, and sending it in."
So far, no green crabs have been found in Squamish, but Godbout-Gauthier warned that “the absence of evidence doesn’t mean evidence of absence.”
However, the ongoing monitoring efforts are still crucial.
“Invasives tend to move with people—whether on vehicles, shoes, or even in soil during development,” she said.
“The more activity we see in the region, the more potential there is for invasives to spread.”
Community involvement and education are key
“Invasive species do not respect property boundaries,” said Godbout-Gauthier.
She believes that "to be successful in managing invasive species, property owners, local governments, industry, and everyone else needs to work collaboratively."
"There’s a handful of what we call behaviour change programs," said Godbout-Gauthier.
"One example is Play Clean Go, which encourages people to remove plants and mud from their boots, gear, and pets before entering a recreation area. By starting every activity with clean shoes or a clean dog leash, you help prevent the spread of invasives that might be hiding in that mud or stuck to your socks."
According to her, curiosity can also be a powerful motivator in combating invasive species.
"Identifying a plant is a fun puzzle that can keep kids busy on a walk or a car ride for a long time," she said.
"We always invite people to become a little more curious about the world around them."
Efforts to manage yellow flag iris in the Cattermole Slough region have shown some success. In 2022, only three square metres of yellow flag iris were left, and by 2023 and 2024, no plants were observed in Cattermole Slough.
The yellow flag iris is an invasive plant that can be toxic to humans and animals and cause human skin irritations according to the Invasive Species Council of BC.
In 2020, the District of Squamish implemented the Invasive Species Management Bylaw, which, among other provisions, bans the sale of invasive species within the district—marking a first in B.C.
Erin Galloway, SSISC’s Field Program Manager, credits this reduction to the consistent work of the team.
“I think what’s really made a huge impact on the yellow flag iris in the corridor is the consistent time and effort put in by the crew every year to remove the plants,” she said.
How can you help?
So, what can you do to help protect the Sea to Sky region from invasive species?
Reports can be submitted through SSISC’s website, and Godbout-Gauthier told how easy it is to get involved.
“It’s really as simple as snapping a photo with your smartphone and sending it in with a little bit of information. We’re happy to help with the plant’s identification and always communicate with people who report to confirm or correct their hunch.”
Whether by volunteering, submitting reports, or simply cleaning your boots before hitting the trails, there are plenty of ways to make a difference.
“Every bit of awareness helps,” said Godbout-Gauthier.
Note: The article has been updated to clarify the specific area where the yellow flag iris is no longer observed and to highlight that volunteers receive formal training through the Crab Team program.
Bhagyashree Chatterjee is The Squamish Chief’s Indigenous affairs reporter. This reporting beat is made possible by the Local Journalism Initiative.
