TPWD urges boaters to take precautions to stop the spread of zebra mussels and other invasive species

Don’t give ‘free rides’ to invasive species, officials say

Zebra mussels on the bottom of a float at Lake Lyndon B. Johnson in July, 2021. (KSAT 12)

SAN ANTONIO – Texas Parks and Wildlife officials are urging boaters to “clean, drain, dry” ahead of the holiday weekend to help prevent the spread of invasive zebra mussels.

“The July 4th holiday is an exciting time of year for boating in Texas, and while we want everyone to have a great time, we also want them to avoid giving free rides to invasive species and helping them travel to new lakes,” said Brian Van Zee, TPWD Inland Fisheries Regional Director.

There are 27 lakes in Texas that are classified as being infested with an invasive species known as zebra mussels.

“Invasive mussels can be attached to boats or even carried by anchors or attached to plants clinging to boats,” said Monica McGarrity, TPWD Senior Scientist for Aquatic Invasive Species Management. “Microscopic invasive mussel larvae can be transported in residual water in the boat.”

A homeowner on Lake LBJ, about 45 miles northwest of Austin, told KSAT that last summer was the first time she had seen zebra mussels in the lake.

She was shocked to find the family’s float covered in Zebra mussels last July.

“Zebra mussels can wreak havoc on a family lake. They multiply quickly and are sharp and can cut up feet on ladders,” Entzminger said.

Zebra mussels and giant salvinia continue to spread to new areas in Texas, TPWD officials said.

Giant salvinia are free-floating aquatic plants that can double their coverage of any given area in just one week. The plant produces thick surface mats that make fishing, boating, swimming and other water recreation nearly impossible.

TPWD officials said giant salvinia is currently present in 23 East Texas lakes and numerous rivers, creeks and marshes between Houston and Beaumont.

“The best way to prevent the spread of many destructive aquatic invasive species is to clean, drain and dry your boats and equipment – every time,” said Van Zee.

According to TPWD officials, zebra mussels arrived in North America sometime in the late 1980s and spread like wildfire via the Mississippi River and have traveled overland on boats as far as California.

“Microscopic invasive mussel larvae can be transported in residual water in the boat. Taking just a few minutes to clean, drain, and dry boats can make a huge difference in our efforts to prevent further spread of this highly damaging species and harm to Texas lakes,” said McGarrity. “Boats with attached mussels need to be properly decontaminated before moving them to a new lake.”

Boaters are asked to remove all plants, mud and debris from boats, trailers, vehicles and gear and drain all water from the boat, equipment and onboard receptacles before leaving the lake.

TPWD recommends letting a boat dry for at least one week before visiting a different lake. If drying isn’t possible, TPWD recommends washing the boat with high-pressure water from a carwash or spray nozzle on a water hose before visiting another lake to help reduce the risk of spreading aquatic invasive species.

Anyone who sees an invasive species in a lake where it hasn’t previously been reported is asked to call TPWD at (512) 389-4848 or send an email, with photos if you have them, and specific location information to


About the Author:

Mary Claire Patton has been a journalist with KSAT 12 since 2015. She has reported on several high-profile stories during her career at KSAT and specializes in trending news and things to do around Texas and San Antonio.