What Mussels?

Zebra Mussel

Zebra Mussel – US Fish & Wildlife

Quagga Mussel

Quagga Mussel – National Park Service

Zebra and quagga mussels are closely-related mollusks that originate from Europe and are non-native to North America. They live in freshwater – such as lakes and rivers – and are invasive, known to encrust and corrode hard surfaces and cause serious harm to waters where they become established.

Fortunately, as best as we know, the Okanagan is still free from invasive mussels.
Let’s keep it that way.

Have the Talk
Prevent Aquatically Transmitted Species

It’s not always easy to talk with neighbours, friends or family, but if you love our lakes… it’s OK to have “the talk.”

If you have a neighbour, perhaps a snowbird who takes their watercraft south with them for the winter, or a brother-in-law who’s bringing their water toy out from the East Coast as part of their Okanagan vacation plans, HAVE THE TALK!

Make sure they are aware of invasive mussels and the need to “Clean, Drain, Dry” their watercraft, and other water-related gear, to protect our lakes.

It wouldn’t take long for the mussels to get established once they arrive. Each female can produce about 1 million eggs per year. And, the mussels can be spread unknowingly by boaters, fishers and other well-meaning nature lovers. At their youngest stage, the invasive mussels are the size of a grain of sand. At their largest they are the size of your thumbnail (1.5 to 2 cm). They are often brought in on boats and other recreational water toys (e.g. kayaks). But they can also come in on hipwaders, fishing tackle boxes, life jackets and other objects that have spent time in infested waters.


They were first introduced to Canada’s Great Lakes region and the United States in the 1980s after ballast water was discharged by vessels traveling from Europe.


The mussels have been in the Great Lakes in Ontario and Quebec since the late 80's but were discovered in Lake Winnipeg, Manitoba in October 2013 and then in Cedar Lake, Manitoba this past October 2015. They are also in at least 24 American states, including California and Colorado. In an effort to stop the spread, Oregon, Idaho, Washington, Montana, Alberta and B.C. are working together on prevention efforts.


Both invasive mussel species are sometimes referred to as “zebra” mussels because they both have light and dark alternating stripes. Quagga mussels are actually a distinct, but similar, species named after the quagga – an extinct mammal which closely resembled and was related to the zebra.


A recent study conducted for the Okanagan Basin Water Board found that an invasion of zebra and/or quagga mussels in the valley could impact

  • Our drinking water intakes and distribution system,
  • Stormwater and treated sewage system outfalls,
  • The safety of our drinking water with the promotion of toxic algae,
  • Aquatic infrastructure (e.g. marinas, public and private docks, Kelowna’s WR Bennett Bridge),
  • Boat motors, sea-doo and other motorized recreational water toys – but also float planes,
  • The natural ecology of the lake, putting at risk native species and resulting in the collapse of our fishery,
  • Real estate values, especially waterfront property,
  • Enjoyment of our beaches with the introduction of razor-sharp shells, and the smell of decaying mussels
  • Okanagan tourist economy - with fewer visitors due to our fouled beaches and loss of our fishery
  • Our economy with the loss of tourism jobs and increased taxes to help manage the mussel infestation and its impact on local government infrastructure


In the Great Lakes region alone, invasive mussels cost $5 billion from 2000 to 2010 to manage.

A 2009 report by the US Corp of Army Engineers estimated that an invasion of mussels in California’s Lake Tahoe region would cause $22 million in annual losses. These losses would be in tourism, reduced property values and increased maintenance costs for public and private aquatic infrastructure (e.g. boat lifts, docks, fueling stations, bridges, water intakes and outflows).

Considering the impacts noted above, a study conducted for the Okanagan Basin Water Board in 2013 found the cost to our region could be at least $43 million each year in lost revenue, added maintenance of aquatic infrastructure and irreparable ecological damage. And in 2015, the Pacific NorthWest Economic Region (PNWER) estimated the cost of an invasion at $500 mill. annually to the Pacific NorthWest.

DON’T MOVE A MUSSEL – Learn more.
Help spread the message. NOT the mussel.

Okanagan WaterWise is an education and outreach program of the Okanagan Basin Water Board

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