Aquatic Invasive Species

Aquatic Invasive Species Profiles: (under construction)


Zebra and Quagga mussels not known in BC

(Dreissena polymorpha and D. bugensis)

Zebra and Quagga mussels are two species of freshwater shellfish that are not yet known in BC.  If accidentally imported they could damage our aquatic environment, our economy, and our enjoyment of our waterways.  Prevent the spread of these species by always stooping at inspection stations when bringing any watercraft to BC.  Click to watch the Mussel Threat video. For more information see the BC Government Invasive Mussel site.


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Invasive freshwater clams – confirmed in Salmon Arm of Shuswap Lake

(Corbicula fluminea)

Corbicula fluminea are small invasive freshwater clams with a triangular shell.  They are found in silty to sandy to gravel substrates in shallow areas of lakes or rivers.   C. fluminea can self fertilize and reproduce rapidly, with a single clam producing up to 70,000 eggs/year.  C. fluminea can spread by human transport and water currents and have been sold for aquarium use.

Recent surveys have found invasive clams in the Salmon Arm of the Shuswap Lake.

Substrate surveys detected live clams at Sunnybrae and Canoe. Beach walking surveys found shells at Sandy Point but have not found clams at any locations outside the Salmon Arm of the lake.  The surveys were conducted by the Columbia Shuswap Invasive Species Society with funding from the Shuswap Watershed Council, direction from the Ministry of Environment and Climate Change Strategy, and assistance from the Invasive Species Council of BC Job Creation Program.

So what can be done?  Unfortunately, once established, eradication of Corbicula fluminea clams from a complex, connected water body is very unlikely and management methods are limited.  Impacts to the system are difficult to predict and depend on several factors. The best thing you can do is prevent further spread to other lakes or rivers.  Clean, Drain and Dry your gear and watercraft, and never release live animals or plants into waterways. Extent surveys are still under way and CSISS will continue to post updates as we learn more.

Invasive clams found at Sunnybrae

Please help prevent further spread of the clams.

Clean, Drain and Dry all watercraft, fishing gear, and water toys before moving from one water body to another or from the Salmon Arm to another part of the Shuswap Lake.

There are several species of native mussels in the Columbia Shuswap region.  Adult native mussels are much larger and more elongate than the small triangular adult clams. Click to download our printable Who’s Who Freshwater Shellfish poster.

Interesting facts about invasive clams…

Many, but not all C. fluminea clams are hermaphrodites and can self fertilize.  They brood their young in their branchial water tubes and release them into the water column when they are almost fully formed.  The juveniles have mucilaginous byssal threads which they can use to cling to the sediment, vegetation or hard surfaces.  Turbulent water movement can dislodge them and cause them to float to new locations (Sousa et al. 2008) 

See more information on the Invasive Clam Alert (Corbicula fluminea)

American Bullfrog – not known in the Columbia Shuswap region

(Lithobates catesbeianus)

American Bullfrogs are native to Eastern North America.  They were brought to BC as farm animals last century for their meaty legs.  Unfortunately some animals were released.  These large frogs are generalist predators and eat other frogs, reptiles, small fish, baby birds, and even small mammals. Most places where bullfrogs exist in western Canada, the biodiversity plummets.  Never release captive animals. 

Learn to identify American bullfrogs – Invader-Alert-Bullfrog

Columbia Shuswap American Bullfrog Risk Assessment

Whirling Disease

rainbow-whirling-disease copy

Whirling disease affects all salmonid fishes, including salmon and trout.  It has the potential to decimate these fish species and can be accidentally transmitted through the movement of fish (alive or dead), water, mud or plant matter.   Whirling disease has been found in the Bow River watershed and may be present on other waterbodies.

  • Do not transport fish (alive or dead) from one body of water to another.
  • Do not dispose of fish entrails into any body of water or into your garberator.
  • Drain boats, equipment, coolers, live bait wells onto dry land.
  • Thoroughly wash mud from vehicles, boats, trailers, waders, boots, and fishing equipment.
  • Never transport aquatic plants, and make sure all equipment is cleared of weeds after every use.
  • Spores are particularly persistent in felt soled wading shoes. If you have any doubt about contamination, you may treat these with a solution of 10% chlorine bleach and water for at least 15 minutes. Thoroughly rinse with water before using your waders to prevent residual chlorine from entering streams.

For more information about whirling disease see the Canadian Food Inspection Agency website.



In the Columbia Shuswap Regional District, invasive Eurasian Water Milfoil can be found in Shuswap Lake, Little Shuswap Lake, Mara Lake and the Shuswap River.  As with most invasive plants, once milfoil establishes, it is almost impossible to eradicate. Prevention is the best method to stop its spread, remember to Clean, Drain, Dry your boat!

For more information visit the CSRD Milfoil Control webpage.


Where are the Aquatic Invasive Species?




All species: Early Detection & Distribution Mapping Systems
All species: U.S Geological Survey 
Invasive Mussel Monitoring: Aquatic Invasive Species Network