AUSTIN (KXAN) — More than 30 lakes across Texas are infested with zebra mussels, according to the Texas Parks and Wildlife Department.

The invasive species was first detected in Lake Texoma, north of Dallas, in 2009. Now, a total of 32 lakes in Texas are infested, most recently Amistad Reservoir on the border with Mexico.

Zebra mussels have also been detected in a further four lakes and are suspected in one more. Most of the infested lakes are clustered in central and north Texas.

“It is disheartening that they have now been spread all the way to our southernmost border, but many Texas lakes remain uninfested, underscoring the importance of boaters doing their part to clean, drain and dry their boats when leaving any lake, every time,” said Monica McGarrity, senior scientist for aquatic invasive species at TPWD.

There is one success story: Lake Waco. Zebra mussels were first detected in the lake in 2014, but by 2021, the lake was declared free of the species. The zebra mussels had been eradicated.

How to prevent spreading zebra mussels

Zebra mussels are often spread from lake to lake on or in boats. TPWD says the mussels attach to boats or anything left in the water, like anchors, and can survive for days out of the water. The larvae are not visible to the naked eye, so oftentimes boaters don’t know they’re transporting them.

“There are far more lakes in Texas that still haven’t been invaded and are at risk,” said Brian Van Zee, regional director for TPWD Inland Fisheries. “Each boater taking steps 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.”

TPWD encourages boaters to clean, drain and dry boats and gear before moving between lakes. This includes removing all plants, mud and debris. Everything should be allowed to dry completely for at least a week, if possible.

Boats that have been stored in lakes with zebra mussels are likely infested and pose “an extremely high risk for transporting these invasive species to a new lake,” TPWD said. Boaters can call the department at 512-389-4848 for guidance before moving the boat.

Transporting zebra mussels is illegal and can result in fines of up to $500 per violation. Boaters are required by law to drain all water from boats and onboard receptacles, such as bait buckets, before leaving or approaching a fresh water body.