MARQUETTE — During a periodic inspection and dewatering of the outlet works at Kanopolis Reservoir on Sept. 26, officials with the Kansas Department of Wildlife, Parks and Tourism (KDWPT) and the U.S. Army Corps of Engineers discovered an adult zebra mussel in the stilling basin. Sampling of water in the lake revealed the presence of zebra mussel veligers, the larval form of the mussel. This population was detected at a very early stage, so it will be some time before the full impacts of the infestation will be seen. However, the discovery marks the 14th Kansas reservoir infested by this invasive species, which disappoints KDWPT aquatic nuisance species biologist Jason Goeckler because he knows the spread can be prevented.
“Some of the recent discoveries in eastern Kansas reservoirs were expected because zebra mussels naturally move downstream from infested lakes,” Goeckler explained. “Like the infestation at Melvern Reservoir earlier in the year, the introduction to Kanopolis could have been prevented. We can and must work together to prevent further spread of aquatic nuisance species. Lake users need to take a few minutes to follow the basic clean, drain, and dry precautions.”
Boats that are moored in a zebra mussel lake and then moved without taking precautions pose the highest danger for spreading zebra mussels. Western lakes have not been at a very high risk because of their lack of proximity to zebra mussel waters, but now that these two regional lakes both have growing populations of the mussels, lake users should be on guard more than ever. Costs to public water users continue to go up as each lake becomes infested.
All un-infested Kansas waters are under continual zebra mussel surveillance by KDWPT staff. The veligers in Kanopolis and other lakes are too small to see with the naked eye and suspend for several weeks in the water before sinking to the bottom and attaching to a hard surface. While they are suspended in the larval stage, zebra mussels can be easily transported downstream in flowing water or with water in boats and bait buckets and through other recreational activities.
Zebra mussels are native to the Black and Caspian seas in Europe. They are believed to have been transported to the Great Lakes in the ballasts of transoceanic ships. Since first being discovered in 1988, zebra mussels have spread quickly to other waters in the Midwest. Control is expensive, and there is no way to eradicate them once they become established.
While an adult zebra mussel is only about the size of a dime, the species poses a threat to native Kansas fish and aquatic animals. One adult female can produce as many as 1 million eggs per year, and zebra mussel colonies quickly become quite dense, attaching to any hard surface, including native mussels, crayfish, turtles, boats, docks, as well as water intake structures. They even attach to other zebra mussels, creating layered colonies up to 6 inches thick. Densities of more than 1 million zebra mussels per square meter have been documented in Lake Erie. In addition to the threat they pose to the environment, native species, and water recreation, zebra mussels cost water suppliers, power plants, and other water-related businesses $1 billion each year — costs everyone pays.
Adult zebra mussels are filter feeders, and an infestation can dramatically disrupt a lake’s food chain by removing plankton native fish rely on. KDWPT biologists have documented decreases in body condition and abundance in several game fish species after zebra mussel infestations. Zebra mussel feeding habits may also increase the potential for blue-green algae blooms, which can be toxic to humans and animals. Dense colonies of zebra mussels make wading and swimming along shorelines dangerous because of their sharp shells. When zebra mussels die, the odor and shell fragments that wash up make any shoreline activities unpleasant.
With this latest discovery, KDWPT will increase local outreach efforts through signage and information materials in an attempt to educate lake users about the dangers of spreading zebra mussels. All lake users are asked to help stop the spread of zebra mussels to another water body. Goeckler reminds all anglers and boaters to remember three simple rules: CLEAN, DRAIN, and DRY. Inspect vessels for any zebra mussels before leaving the boat ramp area. (Zebra mussels are on the prohibited species list, which means they can’t be possessed alive. Having a live zebra mussel attached to your boat is a violation.). Drain all water from the boat’s livewell, baitwell, and sump area. Drain any bait buckets, as well — never pour live bait into the lake; dispose of it on land. Dry the boat and trailer for at least five days before putting them in another lake, or wash the boat and trailer with 140-degree water.
“It’s important that lake users take the threat of aquatic nuisance species seriously,” Goeckler added. “If their spread is allowed to continue, our water-based recreation opportunities may be changed forever.”
Zebra mussels are just one of several invasive species that threaten Kansas waters. Prevent their spread by following the CLEAN, DRAIN, and DRY procedures and never move water or fish from one body of water to another. For more information about aquatic nuisance species, go to www.kdpwt.state.ks.us and click on the “STOP AQUATIC HITCHHIKERS” window on the lower right side of the homepage.