Facts and FAQs about AIS

Environmental DNA (eDNA) consists of tiny fragments of genetic material found in the environment. In a lake, eDNA can come from living or dead organisms, or be transferred by boats, water toys, or other objects. Zebra mussel DNA cannot become an adult zebra mussel.

Zebra mussels are small, clam-like aquatic animals native to Eastern Europe and Western Asia. They are 1-3 cm (0.4-1.2 inches) long, have triangular or “D” shaped shells, and most have light and dark brown bands on their shells.

Zebra mussels were discovered in Lake Erie in the mid-1980s. They were accidentally transferred from their native range by cargo ships. Within a decade, the mussels had spread throughout the Great Lakes and many inland water bodies in the Mississippi watershed to the Gulf of Mexico.

Since then, they have spread to hundreds of other water bodies, mainly in eastern North America.

Facts:

• Aggressively invade new areas and reproduce quickly. Females produce upwards of one million eggs per year.
• Colonize almost any hard underwater surface, including watercraft hulls and can interfere with engine cooling systems.
• Power plants, water treatment plants, and cottages can be negatively affected by clogged intake structures.
• Threaten native fish and wildlife by reducing algae and food resources at the base of the food chain.
• Costly nuisance to boaters, commercial fishers, anglers, and beach-goers. They can reduce recreational potential by littering beaches with sharp shells and producing foul odours from decaying, dead zebra mussels.
• Adult zebra mussels can survive out of water up to 30 days depending on temperature and humidity. Zebra mussel veligers (larvae) are not visible to the naked eye and can survive in very little water.

eDNA can serve as an early warning sign that zebra mussels are present, but it does not guarantee that there is an active population. It could take up to four years to determine whether zebra mussels have begun to colonize Clear Lake.

Not necessarily. It is not a guarantee that there are zebra mussels in Clear Lake. It could be “washout” DNA that was transferred from another lake.

DNA may come from a living organism, a dead organism, or an object with DNA on it. For example, DNA could have been shed by a mussel in Lake Winnipeg. Water containing that DNA may have dried on the surface of the boat. That DNA could then have been transferred to Clear Lake and ended up in a sample we took in early August 2022.

 

No. Zebra mussels reproduce when females release eggs that get fertilized by males. Those fertilized eggs can grow into adult zebra mussels.

It can take up to four years to confirm if zebra mussels have populated a body of water. An adult zebra mussel or veliger (larvae) is needed in order to confirm a population.

Aquatic organisms that have spread outside of their natural, historic range. They can be plants, animals, fungi, or bacteria that have been introduced to a new body of water either on purpose, or accidentally. AIS are a significant threat to the ecological, cultural, and economic integrity of all aquatic ecosystems.

If AIS, such as zebra mussels, enter park waters, the consequences could be extremely damaging. They can negatively affect both the environment and the economy. They reproduce quickly, have no natural predators, and outcompete native species for resources.

Our beaches could be covered in sharp shells, fish populations might decline which would impact fishing, our drinking water infrastructure might be at risk, and the costs to repair damages could be high.

AIS, often referred to as aquatic hitchhikers, are commonly spread on wet items such as:

• Watercraft (boats, canoes, kayaks, paddleboards, dinghies) and trailers
• Inflatables (floaties, air mattresses, stand-up paddleboards)
• Snorkeling and scuba diving gear
• Beach toys
• Fishing gear and bait buckets
• Watercraft equipment (life jackets, anchors, ropes, paddles, and anything else that comes into contact with water)

• Bring your watercraft/equipment for an AIS inspection before you use it in Riding Mountain National Park
• Clean, drain and dry all watercraft, fishing gear, and other water related equipment after use.
• Do not transport any live aquatic animals/plants or water
• Learn which AIS are of concern in Manitoba, the risks they pose, and report all sightings of AIS to Parks Canada Dispatch at 1-877-852-3100
• Never bring or use live bait in park waters. For fishing regulations, please visit: Fishing in Riding Mountain National Park.

Ensure that you are following Riding Mountain National Park. fishing regulations

Starting in 2022, smallmouth bass is no longer subject to the game fish Catch and Possession Limit in RMNP. As a result, anglers who possess a valid fishing license are authorized to catch and possess as many smallmouth bass as they like. If you catch a smallmouth bass, retain it, euthanize it, and take it to the AIS inspection station at the Boat Cove. There, Parks Canada staff will measure the fish and collect information about where and when the fish was caught. Afterwards, you can choose to keep the fish or donate it for further research on population characteristics like age, health, and diet.

Thank you for doing your part to protect the ecological integrity of Clear Lake!

Walleye were introduced through federal stocking programs from the 1920s through the 1960s, ceasing in 1968. Over the last 60 years, Parks Canada’s perspective on stocking non-native fish species has evolved. Introducing non-native species can have unintended consequences for aquatic ecosystems, such as impacts to community dynamics like competition for food or habitat resources and spreading disease.

While the ecosystem impacts of the walleye introduction are unknown, they have been naturally reproducing and co-existing with Clear Lake’s native fish species for nearly a century and can be considered naturalized, meaning that they do not disrupt the native ecosystem.