Texas Officials Report Zebra Mussels Infestation At Lake Buchanan

AUSTIN, TX — The Texas Parks and Wildlife Department has designated Lake Buchanan as "infested" with invasive zebra mussels, officials said on Thursday.

Such a status signified there is an established, reproducing population of zebra mussels in the lake, officials explained in an advisory. The lake is located west of Burnet and north of Inks Lake in the Colorado River Basin.

The designation came about as a result of recent sampling efforts that revealed new evidence of a reproducing population of zebra mussels in the lake. Lower Colorado River Authority scientists discovered zebra mussel larvae in plankton samples taken from three sites around the lake in October, officials added. The agency then confirmed the identity through microscopic and genetic analysis.

Officials added the Lower Colorado River Authority analyzed samples collected in November, and again found zebra mussels at two of the three sites. Then in early December, crews working on a floodgate project at Buchanan Dam discovered several settled zebra mussels, officials added. Additional surveys for settled mussels were conducted by the Lower Colorado River Authority on the shorelines while Lake Buchanan Conservation Corporation volunteers also checked their installed settlement samplers, officials said. Zebra mussels were not detected at any of these locations.

Although few settled mussels were found at the dam, the presence of both larvae and adults and detection of young larvae in samples taken a month apart indicate that a reproducing population is present in the lake, said Monica McGarrity, the Texas Parks and Wildlife Department's senior scientist for Aquatic Invasive Species Management.

“At this time, the results indicate that the population in the lake appears to be small,” McGarrity said. "However, as we have seen in other Texas lakes, the population is likely to increase rapidly over the next few years.”

To date, zebra mussels have not been found in nearby Inks Lake, officials said, but due to its location immediately downstream from Lake Buchanan, it is likely to become infested in the near future. Shoreline surveys at Inks Lake conducted by the agencies, as well as checks of settlement samplers by Boy Scout citizen science partners did not locate any settled mussels, officials said.

Fall plankton samples were also free of zebra mussel larvae, officials added. However, zebra mussel environmental DNA was detected in fall samples from one site on the lake, which could be an early indicator of zebra mussel introduction, according to the advisory. Given the findings, officials urge boaters and home owners on both Lake Buchanan and Inks Lake to keep an eye out for settled zebra mussels and report any suspected organisms with photos to aquaticinvasives@tpwd.texas.gov.

Zebra mussels grow to approximately 1-1.5 inches in length and have triangular, typically striped brown/tan shells. Unlike native mussels or non-native Asian clams, zebra mussels adhere strongly to hard surfaces, officials said.

“Although zebra mussels are now found in 31 Texas lakes, there are still many other lakes in the state that they haven’t invaded. Boaters play a critical role in preventing them from spreading to new lakes," said Brian Van Zee, the inland fisheries regional director for the Texas Parks and Wildlife Department. "Before traveling from lake to lake, clean, drain and dry your boat and gear. Remove plants, mud and debris, drain all the water from the boat and gear, and then open up compartments once you get home and allow everything to dry completely,”

Officials said that those who have stored their boats in the water at a lake with zebra mussels likely have zebra mussels infestation on their watercraft, posing an "extremely high risk" for moving this invasive species to a new lake. Before moving your boat to another lake, boaters are urged to call the Texas Parks and Wildlife Department at (512) 389-4848 for guidance on decontamination.

The transport of aquatic invasive species can result in legal trouble for boaters or transporters, officials warned. Transporting prohibited invasive species in Texas is illegal and punishable with a fine of up to $500 per violation, officials added. Boaters are also required to drain all water from their boat and onboard receptacles, including bait buckets, before leaving or approaching a body of fresh water, according to the advisory.

State officials have created a map showing all lakes where zebra mussels have been found in Texas. For more information on how to properly clean, drain and dry boats and equipment, visit the Texas Parks and Wildlife Department YouTube channel for a short instructional video. Texas Parks and Wildlife Department and partners monitor for zebra mussels in Texas lakes, but anyone who finds them in lakes where they haven’t been found before should report them by emailing photos and location information to aquaticinvasives@tpwd.texas.gov to help identify new introductions.

Moreover, anyone who spots zebra mussels on boats, trailers or equipment that is being moved should immediately report the sighting to the Texas Parks and Wildlife Department at (512) 389-4848. To learn more about zebra mussels and other invasive species in Texas, visit the agency's "Stop Invasives" portal. Information for marinas and owners of boats stored in the water on lakes with zebra mussels can be found on the TPWD website.