Zebra mussels infest Lake Walter E. Long, other Texas lakes at risk

Lake Walter E. Long is infested with zebra mussels, according to the Texas Parks and Wildlife Department.

"They had to have come from watercraft. It's not downstream from another infested lake. They can come in as larvae or residual water in watercraft. They're microscopic. You don't see them, but they can still be there," said Monica McGarrity, Senior Scientist for Aquatic Invasive Species at Texas Parks and Wildlife Department.

Lake Austin, Lake Travis, and Lady Bird Lake are also infested.

Lake Walter E. Long tested positive for zebra mussels' larvae in 2018 and 2019. Biologists searched for mussels in 2021 but didn't find any. 

In August of this year, they did find two adult mussels, indicating an established population.

"I can't say I've personally [not] seen any evidence, but I don't doubt that they are in here, because a lot of people bring their boats from other lakes that do have mussels in them," said John Orth, who frequents the lake.


Zebra mussels can affect infrastructure and hurt people with their sharp shells.

"They can also have impacts on our ecosystem, altering the food web," McGarrity said.

Zebra mussels have been found in 34 lakes in Texas. The ones that aren't infected are still at risk.

"It's critical that you make sure that you take steps to clean, drain and dry your boat so you're not spreading these things to other waterbodies," McGarrity said.

You can be fined for transporting zebra mussels and not draining water from your boat before leaving or approaching public waters.

Zebra mussels can live for days out of water.

"There currently are no effective ways to eradicate them once they've become established. But they certainly could travel from there and infest a new lake," McGarrity said. 

"I have the feeling a lot of people are not terribly careful, so it doesn't surprise me that there are mussels in the lake," Orth said.

If you've been storing your boat at a lake with zebra mussels, it's likely infested. Call TPWD at (512) 389-4848 for guidance on decontamination.

For more information on how to properly clean, drain and dry boats and equipment, click here.

To learn about invasive species, click here.

If you see zebra mussels in lakes where they haven't been reported before or on boats, call TPWD at (512) 389-4848 or by emailing photos and location information to aquaticinvasives@tpwd.texas.gov.