With the discovery this summer of zebra mussels in Lake Ray Roberts in Denton County, officials fear it is only a matter of time before the invasive species is found downstream in Lewisville Lake and then transported by boaters to other lakes across North Texas.
The mussels, which settle on just about any hard surface and litter shorelines with their razor-sharp shells, have proved to be a headache as they’ve slowly moved across the U.S since first being found in the Great Lakes in the 1980s.
Now that zebra mussels are in Lake Ray Roberts — the assumption is they got there by hitching a ride on a boat from Lake Texoma or some other infested lake — there’s nothing stopping them from drifting down the Elm Fork of the Trinity River. They would first reach Lewisville Lake and eventually go all the way to Lake Livingston north of Houston. They were also found in Lake Ray Hubbard, just east of Dallas.
“The concern now is that it puts Lake Lewisville at the threat of infestation,” said Robert McMahon, professor emeritus of biology at the University of Texas at Arlington who has been sampling at area lakes. “With boater movement, it could then easily move to other North Texas lakes.”
Zebra mussels, which are named for their distinctive striped pattern, can wipe out native mussels and mess up a lake’s ecosystem. They first showed up in Texas at Lake Texoma in April 2009, where they quickly filled bays with shells. Last year’s drought killed off a number of the mussels when the lake’s water level dropped, but they’re still found in large number in the lake.
Divers also checked Lake Grapevine last week but haven’t reported finding any zebra mussels. The Army Corps of Engineers and Texas Parks and Wildlife Department are trying to stop the spread with boater-education pamphlets and signs posted at area lakes.