With the July Fourth holiday approaching, the Texas Parks and Wildlife Department is urging boaters to declare their independence from zebra mussels by keeping their watercraft free of the small but insidious invaders.
“The British may not be coming, but the zebra mussels unfortunately are,” said Brian Van Zee, a TPWD Inland Fisheries regional director whose area is ground zero of the zebra mussel war in Texas. “Zebra mussels were first documented in Lake Texoma in 2009 and we’ve got to try to keep them from spreading any farther in this state. If we don’t, the impact on everything from fishing to our water supply could be devastating.”
Native to the former Soviet Union, zebra mussels found their way to the United States via the exchange of ballast water from ocean-going vessels passing through the St. Lawrence Seaway to ports on the Great Lakes. Since then, the rapidly propagating bivalves have been spreading south and east and are currently found in 29 states.
In addition to this holiday reminder for Texas boaters about the importance of cleaning their vessels, TPWD will be implementing a public awareness campaign, “Hello Zebra Mussels, Goodbye Texas Lakes: Clean, Drain and Dry” to better educate boaters on the dangers zebra mussels pose to the state’s aquatic ecosystems, private property and water-related infrastructure such as water supply systems. This campaign will be funded by a coalition of partners, including North Texas Municipal Water District; Tarrant Regional Water District; Trinity River Authority; City of Dallas Water Utilities Department; Sabine River Authority; Canadian River Municipal Water Authority; San Jacinto River Authority, Lady Bird Johnson Wildflower Center and the Angelina and Neches River Authority.
“Our message is simple,” Van Zee said. “If you keep or use your boat or personal watercraft on Lake Texoma, or have operated in out-of-state waterways already infested with zebra mussels, Clean, Dry and Drain your vessel before heading to any other body of water in Texas.”
Of immediate concern in North Texas, he said, are lakes such as Lavon, Ray Hubbard, Lewisville, Grapevine, Possum Kingdom, Granbury and others. These lakes are on the Trinity and Brazos River systems and they are heavily used by recreational boaters.
“In their larval form, zebra mussels are impossible to see with the naked eye,” Van Zee said. “This is why it’s particularly important to Clean, Drain, and Dry boats, even when the boat appears to be clean.”
TPWD recommends this simple, three-step procedure for anyone transporting a watercraft that has been used on Lake Texoma to another water body:
- Clean all vegetation, mud, algae and other debris from the boat and trailer before leaving the lake.
- Drain all water from the motor as well as the livewell, bilge, bait buckets and any other compartments or systems that hold water before leaving the lake.
- Dry the vessel and associated equipment for a minimum of 7 to 10 days during the months of May through October or for 15 to 20 days from November through April. These drying times are approximations, and conditions such as cooler air temperatures, higher humidity and whether or not the vessel is kept in dry storage should be considered.
While these are the easiest preventive measures boat owners can take to help prevent the spread of zebra mussels, boats and other vessels that have been kept on Lake Texoma for an extended period of time and are infested with zebra mussels may require additional cleaning procedures.
Power-washing with water at least 140 degrees Fahrenheit and flushing the motor, bilges, live-wells and other water intake systems with 140-degree water will kill zebra mussels. To be effective the water coming out of the flushed systems needs to reach 140 degrees to ensure the entire system was exposed to water hot enough to kill the mussels.
If it is not possible to clean the internal systems or compartments using 140-degree water, the use of either straight vinegar or a chlorine bleach and water solution (one-half ounce bleach to one gallon water) can be effective at killing zebra mussels as long as the mixture is kept in contact with the mussels for 20 to 30 minutes. Clean water should be used to flush the chemicals and dead mussels from the boat following treatment. Boat owners should check with their manufacturer to be sure using these chemicals will not void their warranty.
Large vessels with complex water intake systems such as those used for cooling the engine, air conditioning or personal sanitation may require decontamination by a boat mechanic or marina.
For more information on zebra mussels and other invasive species see the texasinvasives.org website.
