Zebra mussels, small mollusks capable of forming invasive colonies, damaging pipes and affecting wildlife, have been found in Smithville Lake, according to the Missouri Department of Conservation.
Three zebra mussel shells were found on metal gates used to control water flow through the lake dam. They also attached to a dock at the boat launch ramp near the Camp Branch Marina, said Bill Graham, a department spokesman.
Zebra mussels, which pose no health risk to humans, can attach to hard objects such as metal, boat hulls and water pipes. Graham said it’s unclear how they entered Smithville Lake, a 7,200-acre reservoir just north of Kansas City in Clay County.
The mussels are capable of filtering plankton from water, which adversely affects fish and wildlife that consume plankton. They also clog water pipes, causing problems for boats and docks. It is uncertain how they will affect the sport fisheries and property at the lake because their impact varies from lake to lake, Graham said.
In 2010, a cove near the Camp Branch Marina was treated to kill zebra mussel adults and larvae. That treatment came after adult zebra mussels were found on a boat lift at the marina that had been moved from another lake.
Tim Banek, the department’s invasive species coordinator, said the colony was confirmed at Smithville Lake on Wednesday.
“We are terribly disappointed because our efforts are meant to slow the spread and keep them from being transported from one lake to another,” Banek said. “Whenever we get a new infestation, we don’t know what the entire effects will be. They are a nuisance, if nothing else, and they could ecologically and economically affect whatever lake they invade.”
There is no practical way to eliminate zebra mussels from large lakes once they are established, he said.
Smithville is the fifth reservoir where zebra mussels have been found in Missouri. They also are present at Lake Lotawana in Jackson County.
Authorities have also discovered zebra mussels at Lake of the Ozarks on the Osage River and in Bull Shoals Lake and Lake Taneycomo in the White River system. They have been spotted in several locations in Kansas, including lakes that feed into the Kansas River, which joins the Missouri River in Kansas City, Banek said.
Signs have been placed at Smithville Lake warning boaters that zebra mussels are present and they should not be moved. Boaters can prevent the further spread of zebra mussels by making sure their crafts are cleaned, drained and dried before moving them, he said.