Fort Worth

Invasive zebra mussel populations may explode in North Texas

The march of zebra mussels, which can clog pipes and litter shorelines, continues across Texas unabated.

Tuesday, Texas Parks and Wildlife officials said that Lake Travis near Austin is the latest Texas reservoir found to contain the invasive species. Earlier this month, they were found in Canyon Lake, near New Braunfels.

“This is pretty disheartening for us and our many partners, including marinas, who work to prevent this invasive species from spreading — it’s two new river basins with infestations this year,” said Monica McGarrity, TPWD Aquatic Invasive Species team lead.

Officials monitoring North Texas lakes are concerned that infested reservoirs could see zebra mussel populations soar.

At some of the first infested Texas reservoirs — Lake Texoma in 2009, Ray Roberts in 2012 and Lake Belton in 2013 — explosive gains in population were followed by a dramatic drop-off.

A similar scenario could happen at both Lake Bridgeport, where they were found in 2013, and Eagle Mountain Lake, where they were discovered a year ago, said Darrel Andrews, assistant director of the Tarrant Regional Water District’s environment division.

“I think it’s likely,” Andrews said. “It’s something we’re absolutely preparing for.”

The mussels can be washed downstream but also are transported by boats. Texas law requires boaters to clean, drain and dry their boats before entering a new body of water. TPWD and marinas across the state have tried to educate boaters about the risk of carrying the mussels from one lake to another.

TRWD, which owns both Eagle Mountain and Lake Bridgeport, is sampling monthly from spring to fall at both lakes. They’ve beefed up maintenance to scrub for the mussels, while also coating pipes and intake valves to prevent the creatures from attaching to equipment.

Lake Worth also reported its first infestation a year ago, but the news there is more hopeful, said Tom Hungerford, a TPWD inland fisheries biologist.

There hasn’t been any dramatic growth and the lake’s shallow depth and lack of rocky surfaces make it less favorable for a large population. He said he hasn’t found zebra mussels at the Arrow S boat dock, where they were found last year.

Since zebra mussels only arrived in Texas in 2009, more study is needed, said Robert McMahon, professor emeritus of biology at the University of Texas at Arlington. McMahon has been studying and sampling for the invasive species across Texas.

“So far it’s not been a great year for controlling the movement of zebra mussels,” McMahon said. “Let’s hope we don’t have any more infested lakes this year.

“But it’s early in the game. Research still has to be supported to understand what’s going on in Texas.”

Bill Hanna: 817-390-7698, @fwhanna

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