AUSTIN – Over the holiday weekend, Texas Parks and Wildlife Department (TPWD) is urging boaters to do their part to fight back against aquatic invasive species, such as zebra mussels and giant salvinia, which are threating Texas lakes.
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 to our lakes. These invasive mussels 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. There are still many Texas lakes where zebra mussels have not yet been found, and the proactive actions of boaters 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, a highly invasive, free-floating aquatic fern that can double its coverage area in less than a week is also a major threat to Texas lakes. The invasive plant produces thick mats that make fishing, boating, swimming and other water recreation nearly impossible.
“There’s no doubt that Texans love their lakes,” said John Findeisen, TPWD Aquatic Habitat Enhancement Team Lead. “We also need Texans to take action to help protect their lakes. It only takes a tiny fragment of a plant carried on a boat or trailer to create a new infestation, and preventing invasive species introductions avoids costly, long-term efforts to manage invasive species once they infest a lake.”
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 the ongoing efforts by TPWD to manage this invasive plant, 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 the 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.
On top of the harm aquatic invasive species can cause to aquatic ecosystems and the recreational experience at lakes, transporting these organisms can result in legal trouble for boaters. 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 fresh water and to immediately remove all invasive plants from the boat, trailer, and tow vehicle 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 giant salvinia, 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 finds them in lakes where they haven’t been found before or spots them on boats, trailers or equipment that is being moved can help identify and prevent new introductions by reporting the sighting to TPWD at (512) 389-4848 or by emailing photos and location information to firstname.lastname@example.org. To learn whether zebra mussels have been found in a water body previously, before making a report of a new sighting, visit tpwd.texas.gov/ZebraMusselsMap.