What are Zebra and Quagga Mussels?
Zebra (Dreissena polymorphoda) and Quagga (Dreissena bugensis) mussels are bivalve mollusc species native to the Black and Caspian Seas, brought over to North America by large cargo ships.
What's the Difference? Although zebra and quagga mussels are similar species, it is easy to identify between the two. Zebra mussels can be recognized by their light and dark brown bands that are distinctly zigzagged. Quagga mussels often have light and dark stripes, or they can be solid light or dark brown |
Image Source: Alberta Environment and Parks, 2017
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How are Mussels Spread?
These mussels attach and cluster themselves to hard substrates submerged in water such as boats and other recreational equipment. Both male and female mussels clustering together allows for rapid rates of reproduction.
Adult mussels can survive out of water for up to 30 days. At the veliger (larval) stage, they can survive in standing water for long periods of time. |
DID YOU KNOW? A single female can produce up to one million eggs per year! |
Why are Invasive Mussels a Problem?
A large problem associated with any invasive species is that they do not have natural predators. Zebra and quagga mussels are filter feeding species that target phytoplankton (algae) and can quickly out-compete local filter-feeding species. The presence of these mussels can quickly lead to depletion of fish populations in a water body because of interspecific competition for food. This decline in fish population will severely impact the food chain and the overall trophic structure of a water body.
As mentioned before, zebra and quagga mussels will attach themselves to any submerged surface and multiply rapidly, quickly causing a build up of mussels. These clusters of mussels can cause damage to water infrastructure such as boats, docks, water treatment plants, dams and pipelines. It is estimated that a mussel infestation could end up costing Alberta over $75 million annually.
As mentioned before, zebra and quagga mussels will attach themselves to any submerged surface and multiply rapidly, quickly causing a build up of mussels. These clusters of mussels can cause damage to water infrastructure such as boats, docks, water treatment plants, dams and pipelines. It is estimated that a mussel infestation could end up costing Alberta over $75 million annually.
Visit the Alberta Aquatic Invasive Species Council website for detailed information on these mussel species!
Are Zebra and Quagga Mussels in Alberta?
According to the AEP Annual Aquatic Invasive Species Report of 2016, zebra and quagga mussels have not yet made their way into Alberta’s lakes.
However, we know that invasive species adapt to new environments easily and Alberta’s lake conditions are optimal for mussel growth (large supply of phytoplankton, temperature, pH, salinity), which is why Alberta has been developing prevention strategies. The Alberta Invasive Species Council has developed the Early Detection & Distribution Mapping System (EDDmaps); an interactive map where the public can report and view invasive species distributions across the country. Click below to use EDDmaps and find out where each of these species have been reported in North America: |
Image Source: Alberta Environment and Parks, 2017
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What is Alberta Doing to Prevent Mussel Invasion?
The government has developed the Aquatic Invasive Species Prevention Program, which began in 2013, to ensure that our lakes and rivers do not become contaminated with these species. It is important to know where mussels have been reported and where these boats are coming from in order to prevent them from entering our waters.
Below are a few actions that have allowed Alberta's waters to remain mussel-free for now:
Below are a few actions that have allowed Alberta's waters to remain mussel-free for now:
- Watercraft inspections at high priority water bodies
- Regular monitoring of water bodies (substrate, infrastructure, and veliger monitoring)
- Legislation such as "Pull the Plug!" (It is illegal to transport a watercraft in Alberta with the drain plug still in place- Section 6.1 in the Alberta Fisheries (Ministerial) Regulations)
- Spreading awareness to the public (Clean, Drain, Dry Your Boat campaign)
Prevention is the best available management strategy!
Prevention is the best available management strategy!
Background Image: National Park Service, Lake Mead, Arizona
albertaaquaticinvasives.ca is a collaborative project supported by the Edmonton Trout Fishing Club and Alberta Environment and Parks.