Exotic and Invasive Species
The Zebra Mussel Threat
A native of Eurasia, the destructive zebra mussel was first observed in North America in the late 1980s in the Great Lakes Region. Since then the zebra mussel and its close relative the quagga mussel have spread to various states along the Mississippi waterway and have been reported as far west as California. The first Texas infestation was found in Lake Texoma in 2009.
- Infested Lakes - Six Texas lakes in three river basins can be classified as fully infested with zebra mussels, meaning the water body has an established, reproducing population: Texoma, Ray Roberts, Lewisville, Bridgeport, Dean Gilbert (a 45-acre Community Fishing Lake in Sherman) and Belton.
- “Positive” Lakes - Zebra mussels or their larvae have been detected on more than one occasion in lakes Eagle Mountain, 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.
- “Suspect” Lakes - Zebra mussels or their larvae have been found once in recent years in Lake Fork and Lake Ray Hubbard. These water bodies are classified as "suspect."
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). Lakes are shown as "inconclusive" on the map when zebra mussel DNA or an unverified suspect organism has been found there in the past year.
To combat the spread of this destructive pest, a statewide rule requires draining of water from boats and onboard receptacles when leaving or approaching public fresh waters. Don’t be a carrier—Clean, Drain, and Dry your boat! Learn more about zebra mussels.