The Zebra Mussel Threat
Invasive zebra mussels have devastating economic, recreational, and environmental impacts. The first Texas infestation was found in Lake Texoma in 2009. TPWD and partners closely monitor "positive" and "suspect" lakes, as well as other lakes we consider high risk for zebra mussel introductions (see black dots on map below).
State regulations require draining of water from boats and onboard receptacles when leaving or approaching public fresh waters.
- Infested Lakes - Nine Texas lakes in three river basins can be classified as fully infested with zebra mussels, meaning the water body has an established, reproducing population: Belton, Bridgeport, Dean Gilbert (a 45-acre Community Fishing Lake in Sherman), Eagle Mountain, Lewisville, Randell (local Denison access only), Ray Roberts, Stillhouse Hollow, and Texoma.
- "Positive" Lakes - Zebra mussels or their larvae have been detected on more than one occasion in lakes Lavon, Livingston, Waco, Worth, and Fishing Hole Lake (a small lake connected to the Trinity River below Lake Lewisville). So far there is no evidence of a reproducing population in these lakes. Rivers downstream of infested lakes, including the Red, Leon, and Elm Fork of the Trinity, are also positive for zebra mussels.
- "Suspect" Lakes - Zebra mussels or their larvae have been found once in recent years in Cedar Creek Reservoir, Lake Fork, and Lake Ray Hubbard. These water bodies are classified as "suspect."
- "Inconclusive" Lakes - Zebra mussel DNA or an unverified suspect organism has been found there in the past year.
A Growing Problem
A native of Eurasia, the zebra mussel had arrived in North America by the late 1980s, invading the Great Lakes Region. Since then the zebra mussel and its close relative the quagga mussel have spread to numerous states through the Mississippi waterway and have traveled overland on boats as far west as California.