Ask a Warden
How can I help stop the spread of aquatic invasive species?

Wei-Wei Lin serves as a game warden in the Hill Country after holding posts in Dallas/Fort Worth, the Gulf Coast and South Texas. She was often featured on the TV show “Lone Star Law.” She is happy to answer your questions about the Texas outdoors.

Q: Wei-Wei, my favorite swimming spot was recently overtaken by zebra mussels. Is there anything I can do to stop the spread of these invasive species, and others in Texas waters?
A: Great question! Serving on and around so many water bodies, I am very passionate about “Clean, Drain and Dry,” the Texas Parks and Wildlife Department's initiative to stop the spread of aquatic invasive species. Invasive aquatic plant and animal species can be detrimental to aquatic life, safety, property and water infrastructure, which is why it is important to make sure your boat, personal watercraft and trailers are not transporting such species. The TPWD website contains a complete list of the species of concern in Texas, and I would like to discuss three of those species that I have seen directly affect our wildlife and wild spaces.
My first experience with invasive species was during college when I interned with the U.S. Fish and Wildlife Service. I spent my spring breaks helping remove water hyacinth (Eichhornia crassipes) from local waterways throughout Southeast Texas. Mats of this plant had completely closed off one section of a city pond. Other college students and I removed the plants by hand and disposed of them in the garbage. It was not easy work! If left untreated, those plants would have spread throughout the entire pond, preventing swimming and boating and eventually blocking sunlight and harming native wildlife.
Size does not matter when it comes to invasive species. The tiny zebra mussel (Dreissena polymorpha) will not only damage property such as boats and water infrastructure, but their sharp shells can also injure people venturing out into the water or walking barefoot on the shoreline. Patrolling Canyon Lake just north of San Antonio, I was shocked to see these little shellfish covering almost every surface under the water. Most people had to wear shoes when walking around the shallow areas of the lake. These tiny species can easily get into small areas of boats, motors, docks and anything that touches the water.
The most common invasive species on the Central Texas lakes I patrol is hydrilla (Hydrilla verticillata) or “water thyme.” These species can grow as much as an inch per day! Last summer, I assisted several boaters when their personal watercraft sucked hydrilla into the intake, rendering them immobile. I always remain extra-alert when navigating through the local lakes because the hydrilla can also cause an outboard boat to stall if it wraps itself around the propeller or blocks the water intakes on the lower unit.
These three simple steps ensure you are not spreading invasive species.
Clean: Inspect your boat, trailer and gear and remove all plant material, soil/mud and foreign objects.
Drain: Drain all water from the boat, including the motor, bilge, live wells and bait buckets.
Dry: Open all compartments and allow the boat and trailer to dry for at least one week before entering another body of water. If the boat and trailer cannot be dried for at least a week, wash them with hot, high-pressure water (you can rent a hot water pressure washer from many hardware stores).
Aquatic invasive species don't just inhibit boaters from enjoying our beautiful resources to their fullest potential; they also harm our native Texas species. That is why it's never too late to do our part to prevent their spread.
If a person is found to be carrying these species, they may receive a written citation or warning from a Texas game warden for having harmful aquatic plants or invasive mussels attached to a vehicle or trailer, or failure to drain water from watercraft.
Remember: Clean, Drain, Dry.
Until next time. Stay safe, y'all!
Have a question for the game warden? Email us at magazine@tpwd.texas.gov and we will pass it along to Wei-Wei.