Columbia Shuswap Invasive Species Society
Invasive freshwater clams next to two species of native mussels.
Words by Erin Vieira
There’s so much to love about the Shuswap, but the clean water, beaches, and even enjoying leisure time on a boat or dock is at potential risk due to the small, invasive freshwater mussels called zebra and quagga mussels. While they originated in Europe, these seemingly innocuous species have since invaded several lakes and rivers in eastern and central North America, and as far west as California. Fortunately, they haven’t reached the Shuswap or anywhere in British Columbia, and we all need to pitch in to keep it that way.
Zebra and quagga mussels would have a devastating impact on the Shuswap’s lakes and rivers. These mussels cling to anything below the water’s surface including boats, dock pilings, pipes, rocks, and more. Should these species invade the region and the province, removing them would be an ongoing maintenance requirement with an estimated annual cost of $43 million to BC property owners and taxpayers.
Additionally, zebra and quagga mussels pollute water quality through their filter-feeding, putting the lake and drinking water at risk. Recent studies in the Great Lakes have linked invasive mussels to toxic algal blooms and when they die, they leave a terrible stench. Their small, sharp shells also wash up on beaches, which can ruin enjoyment along the shorelines.
Columbia Shuswap Invasive Species Society
Invasive freshwater clams, also known as Asian Clam or Pygmy Clam, on the shore near Herald Provincial Park.
Unfortunately, there isn’t a way to eliminate zebra and quagga mussels once they establish in large, complex bodies of water such as Shuswap Lake – they reproduce prolifically leading to massive infestations.
So, what can be done? Prevention is the only means. Zebra and quagga mussels can move from lake to lake by attaching to boats and other watercraft, or by being trapped in standing water in a watercraft. Therefore, boaters must take the following steps to prevent an infestation in Shuswap Lake:
Clean, drain and dry your boat, PWC, canoe, yacht tender and/or other watercraft and trailer every time you take it out of a lake or river. Other best practices include washing down waders and fishing gear, draining bilges, and cleaning ballast tanks, bags, baitwells, engine coolant systems, and inflatable water toys on dry land. Also, be sure to soak up the standing water with a chamois cloth. Also, boats, watercraft and/or equipment should be dry before being used in another body of water.
Stop at watercraft inspection stations when you travel with a boat or other type of watercraft. By provincial law, this is mandatory for owners of sport boats, kayaks, canoes, car-toppers, personal watercraft, paddleboards, and sailboats. The inspection stations are free, but failing to stop can result in a large fine. If you’re visiting the Shuswap from outside of BC and didn’t have your boat or watercraft inspected, contact the provincial RAPP line at 1-877-952-RAPP (7277) before you launch.
Kyle Pearce
Recreational boaters have to take on the best practices to ensure Shuswap Lake is kept clean and free of invasive species.
Invasive Freshwater Clams
In addition to efforts of stopping an invasion of zebra and quagga mussels in the Shuswap, it’s important to follow the same measures of preventing the spreading of existing aquatic invasive species to other regions of the Shuswap and BC. Invasive freshwater clams (also known as Golden, Asian, or Pygmy Clam) were discovered in the Salmon Arm reach of Shuswap Lake in 2020. These were the first confirmed live invasive freshwater clams in the area, and they have also been found in parts of the Fraser Valley and on Vancouver Island.
Small triangular-shaped shellfish, invasive freshwater clams are usually less than 2.5 cm (about 1 in), golden brown or yellow-green in colour with distinctive growth rings, and have the potential to harm Shuswap Lake by impacting water quality, reducing biodiversity, as well as consuming food resources and taking over natural habitats of other species. While it’s not yet clearly understood how the clams would specifically impact Shuswap Lake, they can also potentially clog pipes and filters, which would impose costly maintenance.
The eradication of invasive clams is unlikely in a large, complex water body such as Shuswap Lake. The clams’ larvae can collect in small amounts of standing water inside boats and other types of watercraft. So, all boaters and outdoor enthusiasts are urged to exercise the ‘clean, drain, dry’ best practices to avoid the spreading of these clams. Two other prevention measures include never using invasive species as fishing bait, and never dump aquaria contents into the environment or down a drain.
You can report sightings of invasive freshwater clams and other invasive species via the ‘Report Invasives BC’ app. For suspected zebra and quagga mussels, contact the RAPP hotline at (877) 952-RAPP (7277).
The Shuswap Watershed Council is a watershed-based partnership organization that works on water quality and safe recreation in the Shuswap. For more information contact Erin Vieira c/o the Fraser Basin Council in Kamloops at (250) 314-9660 or evieira@fraserbasin.bc.ca and visit www.shuswapwater.ca