Foss Reservoir, a U.S. Bureau of Reclamation lake in Custer County, is now among the 20-plus lakes in Oklahoma where invasive zebra mussels have been confirmed. This non-native aquatic nuisance species has continued to spread throughout Oklahoma waters since first found in the McClellan-Kerr Arkansas River Navigation System in 1992.

Zebra mussels can be detrimental to the aquatic environment by competing with native species and altering the native ecosystem. They also can cause significant economic damage by clustering on water intake structures, boats and boat motors. In only two or three years from first arriving, zebra mussels can significantly populate a body of water.

Zebra mussels are small, thumbnail-size mussels with a zebra-like pattern of stripes. Native to the Caspian Sea region of Asia, they are believed to have arrived in the Great Lakes in 1986 via ballast water from a transoceanic vessel. They have quickly spread and are now found in at least 25 states and two Canadian provinces.

The primary way zebra mussels spread to new areas is by hitching a ride on a trailered boat, said Curtis Tackett, aquatic nuisance species biologist with the Oklahoma Department of Wildlife Conservation. Once these invasive mussels are present in a body of water, there is no feasible way to eliminate them. The best strategy is to prevent them from spreading, Tackett said.

Cooperation from boaters and other people using infested waters is vital in slowing or stopping the spread of zebra mussels. Using the “Clean, Drain and Dry” procedure is highly encouraged.

“Whether your boat has been in infested waters for one day or one year, it could be carrying zebra mussels. A female can release up to one million eggs each season, so transporting just one zebra mussel can spell trouble.

“As a general practice, washing and scrubbing your boat and its equipment, and allowing it to completely dry between uses, will prevent the spread of zebra mussels and many other invasive species.”

Because microscopic zebra mussel larvae can be unknowingly transported in bilges, engine cooling systems, minnow buckets, live wells and anywhere water is trapped, these precautions should be taken to help slow their spread:

• Drain bilge water, live wells and bait buckets before leaving.
• Inspect boats, trailers and equipment immediately upon leaving the water.
• Scrape off any zebra mussels, aquatic vegetation or mud found. Do not return them to the water.
• If possible, dry the boat and trailer for at least a week before entering another waterway.
• Wash boat parts and accessories that contact the water using hot water (at least 140 degrees F.), or spray with high-pressure water.

Oklahoma waters where zebra mussels have been confirmed include Kaw, Sooner, Hefner, Keystone, Robert S. Kerr, Grand, Skiatook, Eufaula, Oologah, Claremore, Greenleaf and Texoma lakes, as well as in the lower Canadian, Cimarron, Arkansas, Verdigris, Washita and North Canadian rivers.

For more information about zebra mussels, visit nas.er.usgs.gov/taxgroup/mollusks/zebramussel or StopAquaticHitchhikers.org.

The Bureau of Reclamation will be working with the Foss Reservoir Master Conservancy District to complete a facility vulnerability assessment of Foss dam and reservoir to identify areas within the dam and water distribution system that may be negatively impacted by zebra mussels.  The assessment will identify measures specific to Foss dam and the water distribution system that can be implemented to avoid or reduce impacts to water delivery facilities.

Source: Oklahoma Department of Wildlife Conservation