Invasive zebra mussels now widespread at Truman Lake

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Kansas City
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Warsaw, Mo. – Zebra mussels, a harmful invasive species, are now present in all arms of Truman Lake, said Mike Bayless, fisheries management biologist for the Missouri Department of Conservation (MDC). Evidence that mussels might be present in the lake was found in prior years. But inspections conducted by the U.S. Army Corps of Engineers in recent weeks have determined that they are now fairly widespread in the lake, Bayless said. This makes it imperative for boaters and anglers at Truman Lake to take steps to avoid spreading zebra mussels to other waters.

Zebra mussels are fingernail-sized bivalve mollusks native to the Caspian Sea region of Asia. The mussels arrived in the United States in the ballast water of ships. They were first discovered in a lake near Detroit in the late 1980s. Since then, they have spread into the Mississippi and Missouri River basins. The mussels reproduce rapidly and can form dense colonies attached to boat hulls, docks, pipes and other submerged materials. Nationally, they have caused billions of dollars in damage. The mussels also filter nutrients from the water that benefit native fishes. No natural or man-made controls are effective in eliminating them from large bodies of water. But they can be prevented from entering new waters.

The microscopic young, called veligers, can survive in lake water left in boat live wells, bilge pumps or bait buckets. Adult mussels attached to hulls, engine drive units and anchor chains can survive several days out of the water. Zebra mussels usually enter new lakes or rivers when a boat or dock is moved from one body of water to another.

Boaters and anglers can help prevent zebra mussels and other exotic species from spreading into new waters by draining, cleaning and drying watercraft, Bayless said. Inspect all parts of boats and motors before moving them, scrape off and trash any suspected mussels however small. Remove all water weeds from boats and trailers. Drain all water from boats and motors while on dry land before leaving a water body. Dump leftover bait on dry land. Wash and dry boats before moving them if your craft was in infested waters for a long period of time.

Zebra mussels have been found in Missouri in Smithville Lake, Lake Taneycomo, Bull Shoals Lake, Lake of the Ozarks, the Missouri River and the Mississippi River. They also occur in Lake Lotawana in the Kansas City area, the lower Meramec River in the St. Louis area, and in rivers that drain into Missouri from other states. MDC encourages all water recreationists to help keep them from spreading to other waters, Bayless said.

For more information on zebra mussels in Missouri, visit