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Aquatic Invasive Species

What are aquatic invasive species? 

Aquatic invasive species are non-native plants, animals, fish, algae and invertebrates that have been introduced to new aquatic environments without the predators or pathogens that help keep them in check in their native habitats. Without their natural enemies, these invaders are able to rapidly reproduce and outcompete native species. Once these species are established, they are extremely difficult, if not impossible, to eradicate. Aquatic invasive species have already been responsible for significant devastation of some native fish species and fisheries in Canada.


Water-based recreational activities such as angling, boating and diving can spread aquatic invasive species into new bodies of water. Plants, animals, and microscopic creatures can cling to clothing, equipment and boats. Prevention activities such as Clean, Drain, Dry is the best way to ensure aquatic invasive species do not enter our lakes. 

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Smallmouth Bass. Credit - US Fish and Wildlife Service

What are their impacts? 

  • Aquatic invasive plants like milfoil can form thick mats on the surface of the water, which impedes light penetration to underwater plants and animals, hinder boat traffic, clog intake pipes of boats, foul fishing lines and nets and cause a danger to swimmers. 

  • Many aquatic invasive species can cause increased boat repair and maintenance costs when they become tangled or grow in motors. 

  • Real estate values can become depressed on waterbodies with aquatic invasive species infestations. 

  • Aquatic invasive species can outcompete native species for food and habitat, and alter food webs. 

  • Species like zebra and quagga mussels can rapidly colonize hard surfaces and can subsequently clog water-intake structures, impact recreation, and affect water quality.

Species Highlight - Zebra and Quagga Mussels 

Zebra and quagga mussels (also known as invasive mussels) are small, freshwater bivalves that are usually cream coloured with darker bands or stripes. They are non-native and can cause damage to the environment, the economy, and human health once established. They are originally from Eastern Europe. In the mid 80s they arrived in North America in the ballast water of ocean liners and since then they have spread across the continent through the waterways and overland on trailered boats. To date, there has been no reported introduction of live zebra or quagga mussels into B.C. lakes or waterways. Zebra and quagga mussels are not established in British Columbia, Alberta, Saskatchewan, Oregon, Idaho, or Washington – and we would like to keep it that way!

Zebra and quagga mussels can be spread between lakes by contaminated watercraft, boat trailers, live bait wells, and even fishing gear. Adult zebra and quagga mussels can attach to virtually any solid surface. The young mussels float in water for the first month, so they will naturally move into lakes and rivers and can be moved unknowingly in bilge or ballast water, or live wells.

A study conducted in 2013 estimated that it could cost the Okanagan up to $43 million dollars if invasive mussels were to arrive. However, the value of our ecosystems, water quality, and the beauty of our lakes is priceless! 

We all need to take responsibility to protect the Okanagan from the devastating impacts of zebra and quagga mussels. At this time there are no known methods for eliminating invasive mussels without severely damaging the ecosystem of the water body in which they’ve been found. The public’s help in preventing the spread of these highly invasive species is essential. 

We are proud to be working in cooperation with the Okanagan Basin Water Board on their Don't Move A Mussel campaign. We appreciate their financial and in-kind support for our aquatic invasive species prevention program.

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Dont move a mussel

Invasive Mussel Resources

Don't Move A Mussel Website

BC Government Website - Stop the Spread of Invasive Mussels

Invasive Mussel FAQ

Learn frequently asked questions about invasive mussels. 

Invasive Mussel Interactive Video

Learn about how invasive mussels could affect the things we love most about the Okanagan through an interactive video.

"Invasive Mussels - Why Care?"

A video that discusses why you should care if invasive mussels established in the Okanagan Valley.

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Invasive mussels in hand

"If they get over the Continental Divide, then British Columbia, Idaho, Washington and Oregon are all vulnerable. No matter how many inspection stations we have, they’ll just float downriver. And it’s not just a tourism matter. We estimate it

will cost the region a half-billion dollars a year for the rest of our lives just to manage impact on hydro, irrigation and fisheries,

especially our salmon habitat."


- Matt Morrison, CEO of the Pacific Northwest Economic Region (2016)

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Zebra mussels attached to boat hull

Okanagan Invasive Mussel Monitoring 

Since 2013, OASISS has been monitoring Kalamalka, Wood, Okanagan, Skaha, and Osoyoos lakes in the Okanagan valley for presence of invasive mussels through both plankton tows and monitoring stations. This sampling is conducted in partnership with the Ministry of Land, Water and Resource Stewardship as part of the Invasive Mussel Defence Program. Each year we collect up to 150 water samples, which represents up to 18% of the provincial invasive mussel monitoring effort.

Every year so far, the results all have come back negative - NO invasive mussels found!


OASISS has received a Habitat Conservation Trust Foundation grant for the invasive mussel monitoring, with funding provided by the BC Ministry of Land, Water and Resource Stewardship. The Ministry has received support for invasive mussel monitoring from Fisheries and Oceans Canada through the Canada Nature Fund for Aquatic Species at Risk.

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Sam sampling for invasive mussels

Citizen Science Project

In 2021, OASISS launched a citizen science initiative to help monitor for invasive mussels and clams in Okanagan lakes. Since then, OASISS has worked with over 50 volunteers!

The project offers two types of volunteer positions during the summer. The first position seeks homeowners who have private docks on Kalamalka, Wood, Okanagan, Skaha, and Osoyoos Lakes to monitor for zebra and quagga mussels. Volunteers receive a pair of mussel monitors to be attached to their docks and are required to check them every two weeks. The second position seeks community members to conduct shoreline surveys for invasive clams on designated beaches on Osoyoos Lake. No invasive species of concern have been detected to date!

We are looking forward to continuing the citizen science project in coming years. If you are interested in getting involved, check out our Volunteer Opportunities page.


Thank you to the RBC Foundation for funding this important initiative in 2021.


Volunteers checking mussel monitors

Aquatic Invasive Species Profiles

Click on a species to learn more information.

Credit: B. Stewart

Credit: USDA

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