Zebra and Quagga Mussels

Invasive Species | Fish and Invertebrates

Zebra and Quagga Mussels

*(Dreissena polymorpha, Dreissena bugensis)*
French common name: la moule zébrée et la moule quagga
Zebra mussels (Dreissena polymorpha) are a small invasive freshwater mussel from southwestern Europe (specifically the Black and Caspian Seas) that first arrived in the Great Lakes in the 1980s through infested ballast water that was discharged from ships. Since then, they have been spreading through eastern Canada and the United States impacting ecosystems, recreational activities, and infrastructure.
These two similar species reproduce rapidly and in extremely high numbers. They attach to surfaces using basal threads and can colonize areas with up to 700,000/m2. They drastically alter food webs and water chemistry, compete with native species for space and resources, and impact infrastructure like water in-take pipes and power plants. Mussels produce free-floating veligers (larvae) that float in the water column before attaching to available surfaces. They can also be spread between waterbodies on hard surfaces like boat props and in standing water in bilge pumps, livewells, and on undried equipment. Clean, Drain, and Dry all equipment to help prevent the spread of invasive Zebra and Quagga mussels in New Brunswick.
*(Photo credit: Photo: Randy Westbrooks, Bugwood.org)

What are Zebra Mussels?

Zebra Mussels are invasive freshwater mussels that have been recently found in the Madawaska River, located in northern New Brunswick. They attach themselves to any solid surface (ex: boats, docks, rocks, etc.) in groups up to 700,000 individuals/m2, where they filter the water in large quantities.

They negatively impact freshwater ecosystems by:

Filtering large quantities of water, which can reduce food sources such as plankton and alter food webs.
Increasing water clarity, which can contribute to increased growth of aquatic plants such as Eurasian Watermilfoil.
Altering spawning areas and impacting native species.

They can also affect recreational activities and infrastructure by colonizing hard surfaces and clogging water intake structures.

Life cycle:

Mussels produce free-floating veligers (larvae) that float in the water column before attaching to available surfaces.

Habitat:

Freshwater environments, including lakes, rivers, and human-made waterbodies. Zebra and Quagga Mussels can colonize surfaces including rocks, boats, docks, other aquatic plants and animals, and infrastructure such as water intake pipes.

Impacts:

Zebra mussels are filter feeders that will attach themselves to any solid surfaces touching infested waterways, such as boats, docks, rocks, plants, and native mussels. The females can produce up to 1 million eggs per breeding season, and the free-swimming veligers (larvae) can float in the water column for up to a month before attaching to available surfaces, colonizing in densities of up to 700,000 individual mussels per m2.

The presence of zebra mussels can negatively impact freshwater ecosystems by:

Filtering water to the point where important food sources like plankton are depleted, which alters food webs. The over-filtering also creates clear water, allowing sunlight to penetrate deeper which can increase growth area of invasive aquatic plants like Eurasian Watermilfoil.
Increasing toxic algae blooms, pathogenic bacteria, avian botulism, which impacts fish and wildlife.

Altering spawning areas by changing the materials on the bottom on the waterways, which impacts fish egg survival

Since they are capable of heavily colonizing on various surfaces, they can also negatively impact recreational activities and vital infrastructure. Due to their razor-sharp shell, recreational users are at a risk of cutting their feet while walking on beaches or swimming in water infested by zebra mussels. These invasive mussels are also responsible for clogging intake structures used by water treatments facilities and power plants. The management of zebra mussels can also be costly for local government agencies. Between 2017 and 2019, municipalities in Ontario reported spending $4.5 million annually on the control, prevention, and detection of these mussels.

Report Zebra/Quagga Mussels

Zebra and Quagga mussels are currently found throughout Ontario, Quebec, and Manitoba. If you think you’ve discovered Zebra/Quagga mussels in New Brunswick:

Take photos
Note:
- the exact location (GPS coordinates)
- the observation date
- identifying features
Contact Fisheries and Oceans Canada to report:
- Toll-free: 1-866-759-6600
- Email: DFO.GulfAquaticInvaders-EnvahisseursaquatiquesduGolfe.MPO@dfo-mpo.gc.ca

Key ID Features

Photo: Dave Britton, US Fish & Wildlife Service

Size: very small; range in size from a few millimeters to 4cm. Much smaller than native mussel

Photo: Amy Benson, U.S. Geological Services, Bugwood.org

Shell: both species are triangular in shape. Colour ranges from white to dark brown, with zebra mussels having a zig-zag pattern.

Attachment: attaches to solid surfaces using hairlike byssal threads that extend from underneath their shells.

Help Prevent Their Spread

Clean

CLEAN any mussels and plant material from your boat, trailer, and equipment after each use and with hot water (45°C) when possible.

Drain

DRAIN water from all internal compartments, ballast tanks, live wells, bilges, bait buckets, and motors on land and at least 30m away from the water.

Dry

DRY any remaining standing water using a sponge or towel.

Inspect

INSPECT boats or other equipment (eg. trailers, boat lifts) bought from other areas before placing them in the water.

While we do not perform physical invasive species removal, we empower local communities with the knowledge, tools, and early-detection networks needed to stop invasions before they start

Zebra Mussels in New Brunswick

NBISC works with government, Indigenous, municipal, watershed, research, and community partners to support zebra mussel prevention, monitoring, education, and early detection in New Brunswick. Our work has included:
- Coordinating and supporting zebra mussel monitoring, including eDNA sampling and collector plate monitoring.
- Supporting Clean, Drain, Dry outreach and boat decontamination at high-priority events and locations.
- Working with partners to share information, coordinate prevention efforts, and respond to new detections.
- Providing education and resources to communities, boaters, anglers, and other partners to help prevent the spread of zebra mussels.
September 14, 2023
- We installed and later removed 20 collector plates along the Wolastoq, ranging from Perth-Andover down to the Saint John Marina.
- We collected 30 water quality samples with help from our partners at the KWRC and JSGWA.
- We collected veliger samples with our partners DNRED, UNB Biology, and Canadian Rivers Institute!
- We sampled for environmental DNA (eDNA) at 26 locations in the province, some being in the main stem of the Wolastoq, its main tributaries, and many freshwater lakes.
- Complementing this, we operated our mobile decontamination unit at 20 angling tournaments and other recreation events, ensuring boats were cleaned to help prevent aquatic invasive species from hitching a ride between waterbodies.
- To end our season, we performed visual dock inspections at Woodstock, Nackawic, Mactaquac, Fredericton, and Gagetown.
We are happy to report that no Zebra Mussel were found on the collector plates or the inspected docks, and all eDNA sampling outside of the main stem of the Wolastoq (Saint John River) were negative! We are still waiting on the veliger sampling results. This is great news, as it means the spread of Zebra Mussel has not significantly advanced since last year's monitoring efforts. -Adult mussels were found in the Madawaska River attached to a hydro-electric dam in Edmundston. This detection represents the first occurrence of this highly invasive freshwater mussel in the Maritimes.
For more information, visit:https://www.canada.ca/en/fisheries-oceans/news/2023/09/fisheries-and-oceans-canada-and-its-partners-confirm-the-arrival-of-zebra-mussels-an-aquatic-invasive-species-in-new-brunswick.html
October 2022: We are saddened to share that an established Zebra Mussel population has been discovered in Lac Témiscouata, just across the border into Québec, which flows into New Brunswick’s Madawaska River and then the Wolastoq (St. John) River. The situation is being monitored by respective government agencies and plans are being made to assess any spread beyond the lake. While no populations have been detected in New Brunswick to date, we ask that anyone spending time in the Madawaska or upper Wolastoq (St. John) River to keep an eye out and report any suspected sightings.

Partners

NBISC’s zebra mussel work is supported through collaboration with government, watershed organizations, municipalities, Indigenous organizations, researchers, and community partners.