Lakes McQueeney, Placid Also Added to Statewide List of Lakes with Zebra Mussels

AUSTIN – Established, reproducing populations of invasive zebra mussels have been discovered at two new lakes in Central Texas, Lake Lyndon B. Johnson (LBJ) in the Colorado River basin northwest of Austin and Lake Pflugerville northeast of Austin.

Texas Parks and Wildlife Department (TPWD) and Lower Colorado River Authority (LCRA) biologists confirmed the presence of zebra mussels in Lake LBJ after LCRA staff found about a dozen juvenile and adult zebra mussels near the Thomas C. Ferguson Power Plant in the Horseshoe Bay area July 29. Additional surveys also found juvenile and adult zebra mussels attached to structures in several other locations in the lake near Wirtz Dam, McNair Park and Kingsland Community Park and zebra mussel larvae were found in plankton samples. Zebra mussels are expected to spread downstream from Lake LBJ into Lake Marble Falls where zebra mussels haven’t been found to date.

“It is disheartening to see zebra mussels spreading higher up the chain of the Highland Lakes in the Colorado River basin, as only boats can move this invasive species upstream to uninvaded reservoirs and downstream dispersal is inevitable,” said Monica McGarrity, TPWD Senior Scientist for Aquatic Invasive Species Management. “Zebra mussels haven’t yet been found in Lakes Buchanan and Inks, upstream of Lake LBJ, but their introduction closer to these lakes reinforces how critical it is for boaters to take steps to prevent their spread.”

Lake Pflugerville, a water supply reservoir located northeast of Austin, has also been found to be infested with zebra mussels. TPWD confirmed the presence of zebra mussels at the lake after Inland Fisheries staff found adult zebra mussels attached to aquatic vegetation during a routine survey.

“If you are going to be recreating on these and other lakes in Texas, it is essential to make the effort to prevent zebra mussels from spreading further,” McGarrity said. “If you are on the lake for the day, take the time to properly clean, drain and dry your boat and gear before traveling to another lake. If you store a boat in the water on a lake with zebra mussels or work at a marina where boats are stored, please reach out to us directly to make sure proper decontamination procedures are being followed before any vessel is moved. A single mussel-fouled boat or barge can carry thousands of zebra mussels and cause a new lake to become infested.”

As of August 2019, 17 Texas lakes in five river basins are classified as infested with an established, reproducing population of zebra mussels, including Lake LBJ and Lake Pflugerville. New additions to the list of 11 positive lakes where zebra mussels have been detected on more than one occasion include Lakes Placid and McQueeney in the Guadalupe River basin, downstream of infested Canyon Lake. Three water bodies in Texas are currently listed as suspect, meaning zebra mussels or their larvae have been found only once in recent history. A status map and full list of these lakes can be found on the TPWD website.

“There is currently no effective way to selectively control or eliminate zebra mussels once they get established in a public lake,” said Mukhtar Farooqi, TPWD Inland Fisheries Biologist. “This highlights the importance of clean, drain, dry as our best line of defense for reducing the spread of zebra mussels into new lakes.”

In Texas, it is unlawful to possess or transport zebra mussels, dead or alive. Boaters are required to drain all water from their boat and onboard receptacles before leaving or approaching a body of fresh water to prevent the transfer of zebra mussels and other invasive species. Zebra mussel larvae are microscopic and can survive for days in residual water, and adult zebra mussels can survive even longer out of water, especially in cooler months. The requirement to drain applies to all types and sizes of boats whether powered or not – personal watercraft, sailboats, kayaks, canoes or any other vessel used on public waters.

The rapidly reproducing zebra mussels can have serious economic, recreational and environmental impacts on Texas reservoirs and rivers. Zebra mussels can harm aquatic species, cover rocks, beaches, hard surfaces with sharp shells, clog water intakes, damage or increase maintenance on facilities using raw surface water, and damage boats and motors left in infested waters.

TPWD and partners continually monitor for invasive mussels in Texas lakes, but anyone who finds them in lakes where they haven’t been found before or who spots them on boats, trailers or equipment that is being moved is encouraged to help prevent new introductions by immediately reporting the sighting to TPWD at (512) 389-4848 or by emailing photos and location information to aquaticinvasives@tpwd.texas.gov.

More information about zebra mussels can be found online at tpwd.texas.gov/ZebraMussels. A short instructional video on how to properly clean, drain and dry boats and equipment can be found on the TPWD YouTube channel at https://youtu.be/DMlEwbXmLx8.