After a year-long pause, the Sea to Sky Invasive Species Council (SSISC) returned to Whistler’s lakes this summer to resume its longstanding search for invasive mussels in local waters.
The non-profit organization started scouring Sea to Sky lakes for zebra and quagga mussels as part of B.C.’s Early Detection Lake Monitoring Program back in 2017, but funding challenges forced SSISC to put the project on hold last year.
That’s not because the SSISC crew’s monitoring efforts weren’t important: though neither freshwater species is native to North America, both zebra and quagga mussels have already spread throughout Ontario, Quebec, and south into the U.S., where they’ve become well-established in 24 states stretching as far west as California. The species took hold after being introduced to the continent by ships travelling to Canada’s Great Lakes region from Europe in the 1980s.
Researchers have also discovered the invasive species in Manitoba and Montana, but neither mussel has been found within British Columbia’s borders—at least, not yet.
“So far, so good,” said SSISC executive director Clare Greenberg. “No invasive mussels have been found in Alta Lake or any other waterbody in B.C this year, which is great.”
Zebra and quagga mussels could thrive in B.C. lakes and rivers if they were introduced, according to the experts—with big repercussions.
“If they do arrive and establish in B.C., the cost would be huge in terms of economic impacts and environmental impacts,” said Greenberg.
How do zebra and quagga mussels spread?
Unlike the five species of freshwater mussels native to British Columbia—those are usually about 10 to 15 centimetres long—the tinier zebra and quagga varieties can easily latch onto solid surfaces like boat hulls, trailers, motors, equipment, vegetation and other organisms.
“Basically by hitchhiking on watercraft,” said Greenberg, “and that can be boats, stand-up paddleboards, kayaks, canoes—anything like that.
As long as they’re left in a cool, moist environment, the mussels are capable of surviving out of water for up to a month, she added, further increasing their likelihood of spreading when boats, trailers or other equipment inadvertently carry those mussels between bodies of water.
Additionally, the mussels often attach to these surfaces when they’re just a few millimetres in size, meaning their tiny shells are exceptionally difficult to detect. Fully grown, they reach a maximum length of about three cm. Meanwhile, microscopic, free-swimming zebra and quagga larvae are invisible to the naked eye, but can live in the smallest, shallowest pools of water for several weeks—even if that standing water is found inside boats or other equipment.
“It only takes a small amount of water, that can either be in the bilge or in any sort of cavity in a watercraft,” said Greenberg.
The mussels “reproduce quickly and are extremely difficult to eradicate once they become established in an area,” the provincial government explains in a zebra and quagga mussel facts page posted to its website. “In larger water bodies and complex ecosystems, they may be impossible to eradicate unless they are detected and dealt with early.”
Often forming in clumps, their propeller-shaped shells are brown or cream-coloured, and sometimes display zebra stripes.
A mature female zebra or quagga mussel can produce one million eggs per season, according to the SSISC.
What’s the problem?
The tiny mussels pose a host of serious environmental and economic threats to B.C.
According to the SSISC, zebra and quagga mussels filter out nutrients and micro-organisms like plankton, the base of the food chain for the region’s native aquatic species.
Beyond the species’ ability to disrupt aquatic ecosystems and already-vulnerable salmon populations, the miniscule mussels overgrow to the point of blocking pipes and even dirtying municipal drinking water. The razor-sharp creatures are also known to damage boat propellers and injure swimmers near shores or docks—not exactly ideal for recreation and tourism operators.
They can even “coat beaches, docks, and the propeller and hulls of boats to the point that they become unusable,” the SSISC explains on its website.
In terms of costs, “the estimates used to be about $30 million annually, but they’ve really looked at the [threats] and economists have come up with a much larger number,” Greenberg said.
An economic impact study released in May of this year estimated an invasion would cost B.C. between $64 to $129 million annually, taking into account potential impacts on hydropower, agricultural irrigation, municipal water supplies, recreational boating, tourism, and property values.
“B.C. has a lot of hydropower infrastructure, and invasive mussels do things like clog water intakes and damage infrastructure, so that sort of economic cost is one of the things we’re trying to prevent,” Greenberg said.
What does monitoring look like?
Each summer leading up to last year’s hiatus, SSISC seasonal staff ventured out onto several lakes across the corridor to sample their waters. This time around, “we’re only sampling Alta Lake, because the province has looked at prioritizing which water bodies are most likely to see both the arrival of mussels, and then also lakes that have the most favourable conditions for them to establish,” explained Greenberg.
With Alta Lake named on the priority waterbody list the province published this year, staff from the SSISC grabbed their kayaks and sampling devices and headed to Alta Lake to collect water samples on a monthly basis throughout the summer season, said Greenberg.
“Those samples get sent to a special lab that tests for the presence of veligers, which are early larval life stages of invasive mussels,” she explained.
At the provincial level, the B.C. government supports an entire Invasive Mussel Defence Program dedicated to preventing an invasion. Provincial regulations also mandate anyone transporting a watercraft within the
province must stop at all inspection stations along their route.
Records show program staff inspected more than 20,000 watercraft in B.C. in 2022, and found 13 mussel-fouled boats.
“The risk is real,” said Greenberg. “This is one example of where the province has come in with resources and taken it really seriously, to actively try and prevent these mussels from establishing. Because other states and other provinces in North America have had to deal with it the hard way … We’re
learning from the other provinces and states that it’s better to spend money on the prevention side, rather than the much larger amount of money that would need to be spent if [the mussels] do establish.”
How the community can help
A potential invasion “is a problem that can be solved by cleaning, draining and drying watercraft,” Greenberg explained. “So that’s what we’re asking people to do if they’re moving watercraft between water bodies. The best practice to prevent any spread of invasive mussels and other invasive species is to clean, drain, dry your boat, or your canoe or kayak.
“It’s especially important for Whistler because we do see so many people coming from outside of the region and outside of B.C.,” she added.
Whether you’re launching a yacht, fishing boat, paddle board, or stepping into a stream with fishing gear like boots, waders and bait buckets, that means using proper techniques (and a power wash station, if one is available) to clean all plants, animals and mud from your equipment, drain water from all buckets and bilges onto land, and completely dry each item and watercraft before venturing into another body of water.
The SSISC also offers a free Aquatic Invasives 101 course, a 30-minute online endeavour featuring Sea to Sky-specific curriculum for anyone who spends lots of time near lakes, rivers, or the ocean and wants to learn more.
If you spot a mussel that looks suspicious, either on your boat or near local waters, get in touch with the SSISC via email or its “report an invasive species” feature at ssisc.ca/report, or contact the province directly at [email protected].
“Send a picture,” Greenberg encouraged. “If people see a mussel and they’re not sure what it is, we definitely want to get those reports and make sure to double-check the ID.”
While prevention is the best defence, early detection is the next best thing, Greenberg explained.
Find more info at ssisc.ca.
