TPWD Confirms Established Population of Invasive Zebra Mussels in Lake Meredith

TPWD Confirms Established Population of Invasive Zebra Mussels in Lake Meredith

June 25, 2026

Media Contact: TPWD News, Business Hours, 512-389-8030

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AUSTIN -Texas Parks and Wildlife Department (TPWD) has designated Lake Meredith, near Amarillo, as fully "infested" with invasive zebra mussels. This designation signifies that an established, reproducing population of these invasive mussels is present in the lake.

In late May, detection of potential microscopic zebra mussel larvae in routine samples from three locations in the lake was reported to TPWD by partners with the U.S. Geological Survey Zebra Mussel Monitoring Program. The TPWD Analytical Services lab quickly confirmed these specimens as zebra mussels with genetic analysis.

In addition, partners with the Canadian River Municipal Water Authority (CRMWA) reported the detection of multiple settled zebra mussels on a camp chair retrieved from the lake by informed anglers. The anglers took action and reported the invasive species to the National Park Service only days before the larvae were collected. These mussels were of multiple size classes, suggesting the mussels may have been reproducing in the lake the previous fall, as well as this spring.

The TPWD Amarillo Fisheries District staff rapidly conducted surveys of shoreline rocks at multiple sites on the lake and detected settled mussels of different sizes at all surveyed locations. This confirms the presence of a well-established, reproducing population that is likely dispersed throughout the reservoir.

"Unfortunately, detection of zebra mussels at Lake Meredith is a continuation of a trend in recent years of westward spread of this highly invasive species to new Texas lakes and this new infestation in a new river basin in the Panhandle provides a particularly concerning steppingstone for further spread to uninvaded western states," said Monica McGarrity, TPWD senior scientist for aquatic invasive species. "As boaters visit waterbodies anywhere in the state-or visit from other states, it's important they take steps to properly clean, drain, and dry boats, or have vessels stored in invaded lakes professionally decontaminated. These important steps not only prevent the spread of zebra mussels and other aquatic invasive species but also help anglers avoid facing state fines or even delays for watercraft decontamination as they travel between states."

Zebra mussels, a non-native shellfish that attaches to hard surfaces, pose a significant threat to Texas lakes, altering lake ecosystems and causing harm to native species. They also damage boats and water supply infrastructure and litter shorelines with hazardous, sharp shells that impact lakefront recreation.

"For many years, CRMWA has been working alongside State and Federal agencies to monitor for zebra mussel early detection and successfully prevented them from entering Lake Meredith," said Drew Satterwhite, CRMWA general manager. "These efforts include funding and implementation of "clean, drain, dry" billboards, boat ramp signage, boat cleaning stations, and inspecting boats with zebra mussel detection dogs during large fishing tournament weekends. Now that Zebra mussels are established in Lake Meredith, we will be focusing our efforts towards more comprehensive mitigation strategies to limit the impacts to our water infrastructure."

Because zebra mussels are most often transported on or in boats, boaters play a critical role in preventing them from spreading to new lakes. Zebra mussels attach to boats, as well as anything left in the water, including ropes and anchors. They can survive for days out of water, often hiding in crevices where they may escape notice. Their microscopic larvae are free-floating and invisible to the naked eye, meaning they can be transported unknowingly in residual water in boats.

"Invasive mussels have now spread to 40 Texas lakes, with 35 fully infested, but there are far more lakes that still haven't been invaded and are at risk," said Brian Van Zee, TPWD inland fisheries regional director. "Each boater taking the necessary actions to clean and drain their boat before leaving the lake and allowing compartments and gear to dry completely when they get home can make a big difference in protecting our Texas lakes. Boat cleaning stations already in place at several access points at Lake Meredith can help boaters take steps to help prevent new infestations."

TPWD urges boaters to follow these three simple but crucial steps to clean, drain and dry boats and gear before traveling from lake to lake. Remove plants, mud and debris; drain all water from the boat and gear; once back home, open compartments and allow everything to dry completely for at least a week, if possible.

"The National Park Service remains committed to collaborating with our state and local partners to monitor and minimize the spread of zebra mussels and to safeguard the long-term health of Lake Meredith," said Joe Graff, acting superintendent of Lake Meredith National Recreation Area. "Ongoing coordination among agencies, community organizations, and the recreating public is essential as we address this presence in the lake. We encourage visitors to remain informed, utilize designated cleaning stations, and adhere to all 'clean, drain, dry' requirements to help prevent additional spread."

If a boat or other equipment, such as barges, docks, lifts, pumps, etc., have been stored in the water at a lake with invasive mussels, they are likely infested and pose an extremely high risk for transporting these invasive species to a new lake unless properly decontaminated. Before moving a boat or other equipment that has been stored in the water, call TPWD at (512) 389-4848 for guidance.

In addition to the harm that invasive species can cause to aquatic ecosystems, water infrastructure and the recreational experience at lakes, the transport of these organisms can result in legal trouble for boaters. Transporting prohibited aquatic invasive species in Texas is illegal and punishable with a fine of up to $500 per violation. It's also the law that boaters must drain all water from their boat and onboard receptacles, including bait buckets, before leaving or approaching a body of fresh water. They must also remove all invasive plants from the boat and trailer before leaving a lake.

For more information on how to properly clean, drain and dry boats and equipment, visit the TPWD YouTube channel for a short instructional video. To learn more about zebra mussels and other invasive species in Texas, visit tpwd.texas.gov/StopInvasives.

TPWD and partners monitor for invasive species in Texas lakes, but anyone who spots them on boats, trailers or equipment that is being moved can help prevent new introductions by reporting the sighting to TPWD at (512) 389-4848. Anyone who finds invasive species such as zebra mussels in lakes where they haven't been found before can help identify new introductions by emailing photos and location information to [email protected].