TPWD reminds boaters to "clean, drain and dry" over holiday weekend

The Texas Parks and Wildlife Department is urging boaters to "clean, drain and dry" their boats to help fight against aquatic invasive species threatening Texas lakes, such as zebra mussels and giant salvinia, over the July 4th weekend.

TPWD says that over the past year, zebra mussels and giant salvinia have continued to spread throughout Texas. While these species remain some of the biggest threats to Texas lakes, other highly invasive species can also be spread or introduced by in-state and out-of-state boaters, such as water hyacinth, Eurasian watermilfoil, hydrilla, and quagga mussels.

Zebra mussels, a non-native shellfish that attaches to hard surfaces, pose a significant threat as they can damage boats and infrastructure for water supply and control, alter lake ecosystems, and cause harm to native species. They also litter shorelines with hazardous, sharp shells that impact shoreline recreation.

"Zebra mussels can be carried by anchors or attached to clinging plants, and microscopic zebra mussel larvae can be transported in residual water in the boat," said Monica McGarrity, TPWD Senior Scientist for Aquatic Invasive Species Management. "Taking just a few minutes to clean, drain, and dry boats can make a huge difference in our efforts to prevent the spread of this highly damaging species and the harm they cause to Texas lakes."

Zebra mussels are now found in 33 Texas lakes across six river basins, as well as in river reaches downstream of infested lakes, including in lakes in Central Texas. There are still many Texas lakes where zebra mussels have not yet been found, and TPWD says that proactive actions can help keep those lakes free of these invasive species. TPWD and partners monitor lakes around the state for early detection of zebra mussels, but once they’ve been introduced and become established in a lake, nothing can be done to control or eradicate them.

Giant salvinia is a highly invasive, free-floating aquatic fern that can double its coverage area in less than a week. The invasive plant produces thick mats that make fishing, boating, swimming and other water recreation nearly impossible.

Giant salvinia is currently present on 23 East Texas lakes and numerous rivers, creeks, and marshes between Houston and Beaumont. While giant salvinia is not currently limiting angling or boating access in Texas public waters due to ongoing management efforts, there is still a chance of plants hitchhiking from one lake to another on a boat, trailer, or other equipment.

Boaters need to remove all plants, mud and debris from boats, trailers, vehicles and gear and drain the water from all equipment and on-board receptacles before leaving a lake. In addition, boats should be dried completely before visiting another lake, preferably for at least a week. Washing the boat and compartments using a carwash or spray nozzle on a water hose can help to reduce the risk of spreading aquatic invasive species if drying is not possible.

If you have stored your boat in the water at a lake with zebra mussels, it is likely infested with zebra mussels and poses an extremely high risk for moving this invasive species to a new lake. Before moving your boat to another lake, call TPWD at 512-389-4848 for guidance on decontamination.

Other equipment stored in infested lakes such as barges, docks, hoists and pumps etc. are other potential vectors for spreading invasive species so those items also need to be fully decontaminated before transporting to another waterbody.  

Transporting prohibited invasive species in Texas is illegal and punishable with a fine of up to $500 per violation. Boaters are also required to drain all water from their boat and onboard receptacles, including bait buckets, before leaving or approaching a body of freshwater.

Additionally, anyone who spots zebra mussels on boats, trailers, or equipment being moved should immediately report the sighting to TPWD at 512-389-4848.

TPWD and partners monitor for zebra mussels in Texas lakes, but anyone who finds them in lakes where they haven’t been found before should report them immediately by emailing photos and location information to

An online status map showing all lakes where zebra mussels have been found in Texas. For more information on how to properly clean, drain, and dry boats and equipment, visit the TPWD YouTube channel for a short instructional video.

Information for marinas and owners or buyers of boats stored in the water on lakes with zebra mussels can be found on the TPWD website. To learn more about zebra mussels and other invasive species in Texas, click here.

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