Zebra Mussels

Invasive species are impacting Texas lakes

Photographer: Amy Benson<br /> Source: U.S. Geological Survey

Zebra mussels are having a devastating effect on the state’s natural resources. These highly destructive, invasive species are spreading across Texas lakes by hitching a ride on boats, trailers, jet ski’s, fishing equipment and swimming gear. Zebra mussels only grow to about 1 1/2 inches long; however, they multiply rapidly, one million eggs spawned by one female each year, and with the lack of natural predators in Texas lakes, they can cause tremendous environmental and economic damage.

Why should you care?

This invasive species has already invaded several Texas lakes, and could take over all freshwater sources in Texas. The local lakes we use, not only for recreation but also for our water supply, have been classified as infested with zebra mussels. Lake Georgetown, Stillhouse Hollow Lake and Lake Travis are among the 14 infested Texas lakes.

Zebra mussels pose a devastating threat to our state’s aquatic ecosystems, private property and water supply systems. They cause recreational hardships, damage to the ecosystem and financially impact taxpayers.

This video is actual footage of zebra mussels in Lake Georgetown — our primary water source.

Recreational Impact

  • Desecrate beaches with their sharp shells.
  • Decreases boat fuel efficiency when attached.
  • Damages boat motors, water pumps, air conditioners, and navigation buoys.

Ecosystem Impact

  • Caused an algal bloom that led to a “do not drink” order for half a million Lake Erie residents.
  • Harm native species, including popular sport fish, taking over habitats and damaging lake ecology.
  • Reduces the availability of tiny food particles (zooplankton and phytoplankton), impacting filter feeding fish, important prey for bass and other sportfish.
  • Reduces native mussel and crayfish populations – as zebra mussels can attach to the shells and exoskeletons of these native species and suffocate them.

Financial Impact

  • Disrupts water supplies by completely clogging pipelines and damaging water intake structures, making water more expensive.
  • Decreased property value up to 19% in some areas infested with aquatic invasive species.

What can you do?

    • Spread the word!
    • Clean and thoroughly dry every item that was in or near the water (swimsuits, water shoes, towels, buckets, toys, rafts, etc.)
    • Clean and dry your dog(s)
    • Report any sightings to TexasInvasives.org.
    • If you see a violation, report it to 800-792-4263
    • CLEAN, DRAIN AND DRY your boat, trailer and gear every time you leave a body of water!
      • Remove all plants, animals and foreign objects from hulls, propellers, intakes, trailers, and gear before leaving a launch area.
      • Drain all water from your boat, including the motor, bilge, livewells and bait buckets, before leaving a lake.
      • Dry for a week or more before entering another water body. If unable to let it dry, wash it with a high-pressure washer and hot (at least 140-degree) soapy water.

Transporting Zebra Mussels is ILLEGAL.

Possession or transportation of zebra mussels in Texas is a Class C misdemeanor for the first offense, punishable by a fine of up to $500. Repeat offenses can be elevated to a Class B misdemeanor, punishable by a fine of up to $2,000, jail time up to 180 days, or both.

State law requires boaters to drain all water from their vessel, including live wells, bilges, motors and any other receptacles or water intake systems before leaving or approaching public waters. This applies to all types and sizes of boats used on fresh waters.

Additional Resources:


Photo Credits:

Title Photo: Amy Benson, U.S. Geological Survey; Zebra mussel attached to crayfish (priorlakesassociation.org)

For questions, comments or to learn more please contact Brandon Pritchett at 512-341-3133 or via email.