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Zebra mussels are small non-native, clam-like, aquatic animals that are a significant environmental and economic concern to Manitoba. Native to Eastern Europe and Western Asia, zebra mussels have caused millions of dollars in damage to the Laurentian Great Lakes area and have cost the North American economy billions of dollars to control.
Zebra mussels colonizing a native clam making feeding difficult.
Photo credit: Randy Westbrooks USGS Budwood.org
On July 1, 2010, microscopic, larval zebra mussels were found for the first time in the Red River. The mussels were found where the Ottertail River empties into the Red River at Wahpeton, North Dakota and Breckenridge, Minnesota. This is the first time zebra mussels have been reported in North Dakota.
Previous to this, live zebra mussels were found in (Big) Pelican Lake, Minnesota approximately 50 kilometres south east of Fargo, North Dakota and Moorhead, Minnesota in September 2009. This was the first known incidence of zebra mussels in the Red River watershed.
Zebra mussels were likely transported into Pelican Lake by unsuspecting boaters who previously launched their boat in zebra mussel-infested waters.
Waters from Pelican Lake flow into Pelican River, which flows into the Ottertail River near Fergus Falls, Minnesota and then into the Red River at Breckenridge, Minnesota. All water that originates in the Red River watershed eventually flows into Manitoba and Lake Winnipeg. No adult (with shells) zebra mussels have been identified in the U.S. portion of the Red River to date.
Since the initial introduction in North America in 1985, zebra mussels have steadily invaded south-eastern Canada and the majority of the eastern half of the United States. They have infested the Laurentian Great Lakes, and the Hudson and the Mississippi drainage areas. Zebra mussels are also found in parts of California, Arizona, Nevada, Utah, Colorado and Texas.
Each year thousands of tourists, recreational boaters and anglers flock to Manitoba's numerous lakes and rivers. With this comes the threat of transporting zebra mussels overland to new areas on watercraft, trailers and gear.
Because they can close their shell, adult zebra mussels are able to survive out of water up to 7 to 30 days depending on temperature and humidity. As a result, they can easily be transported long distances on firm surfaces such as:
Young, microscopic zebra mussels can die quickly out of water. However they can easily survive and be transported to new un-invaded areas in almost any remaining water found in (for example):
Once introduced into a new area, young (larval, free-swimming) Zebra Mussel veligers can spread by:
Updated: August 13, 2015Zebra Mussels are located in:
Help protect Manitoba's waters and resources.
Before launching any watercraft or water-based equipment into any Manitoban waterbody such as a lake, river or wetland, and before leaving the boat launch:CLEAN watercraft, trailer, all water-based equipment.
DRAIN all on-board water from the motor, livewell, bilge, ballast tanks and bait buckets. Any hard to completely drain areas should be dried with a dry towel or sponge.DRY all water-related equipment and watercraft completely. One option is to leave the water-related equipment and/or watercraft to dry in the hot sun for at least 5 days (if rinsing with hot water is not available). Leave all compartments open to allow drying. Alternatively, dry for 8 consecutive days in the spring/fall or 3 days of exposure to constant freezing temperatures (-10°C or lower).
DISPOSE of unwanted bait and worms in the trash, and dump bait bucket water on land.
Never release aquarium pets, plants or water into our lakes, rivers or wetlands.
To report a Zebra Mussel or any other AIS from a new location, please take pictures and report a sighting by clicking Report a Aquatic Invasive Species link or call 1-87-STOP AIS-0 (1-877-867-2470).
Aquatic Invasive species (AIS) such as Zebra Mussels, Spiny Waterflea, Rusty Crayfish, and four species of Asian Carp are listed as a schedule attached to the Aquatic Invasive Species Regulation (SOR/2015-0212) under the federal Fisheries Act. Possessing any of these listed species in Manitoba is illegal. To learn about the species subject to prohibitions and controls visit the federal regulation site at the Canadian government’s law website.
Zebra mussels are native to the Caspian, Black and Azov seas of Eastern Europe; they were initially discovered in the Caspian Sea in 1769.
Scientists first discovered a population of zebra mussels in Lake St. Clair in 1988. The zebra mussels were likely transported to North America in the ballast water of a ocean-going ship. This ballast water was then discharged in Lake St. Clair, Ontario, likely in 1985 or 1986.
The zebra mussel (Dreissena polymorpha) is a small aquatic animal that resembles freshwater clams. Zebra mussels grow up to five centimetres (two inches) in length and may live up to five years. Their name originated from the brown and white striped colour of its shell. One mature female zebra mussels can produce up to one million eggs per year depending on water quality conditions.
The eggs hatch into free-swimming microscopic larvae called veligers. During this stage, which lasts for approximately 8 to 33 days, the larvae remain suspended in the water. It is during this stage that the veligers can be transported undetected from lake to lake in bait buckets, live wells, and bilge water.
The distribution of zebra mussels is thought to be controlled mainly by temperature and calcium concentration in the water. They begin laying eggs when water temperatures rise to approximately 12 ºC and continue until it cools below this temperature in the fall. Calcium is required for mussels to develop their hard shell.
Adult zebra mussels can survive out of water, in moist cool conditions, for up to 30 days. They attach to watercraft or other water-related equipment being transported from one body of water to another unless the proper steps are taken to avoid moving them to new areas.
Manitoba Conservation & Water Stewardship, Fisheries Branch
Box 20, 200 Saulteaux Cres.
Winnipeg, Manitoba, R3J 3W3
Toll Free: 1-877-867-2470