
Mussel Muscle
Zebra mussels have bullied their way into Texas lakes.
By Larry D. Hodge
Zebra mussels are a small invasive species that can do enormous damage by attaching to anything in infested waters. They can clog water treatment plant intakes, cover beaches with sharp shells and foul boat motors and hulls. There is no known way to control them once they have become well-established in a body of water.
TPWD recently updated how it classifies lakes — “suspect” for one scientifically verified detection of zebra mussels, “positive” for multiple or repeated detections and “infested” if the water body has a reproducing population.
Texas lakes now classified as “infested” with zebra mussels are Texoma, Ray Roberts, Belton, Lewisville, Bridgeport and Dean Gilbert (a small lake in Sherman).
Lakes Waco and Lavon will be reclassified soon from “infested” to “positive.” Zebra mussel adults have been found in Lake Waco, but no zebra mussel larvae or juveniles have been detected since fall of 2014, suggesting there may not be a reproducing population in that lake.

Researchers in Texas have found zebra mussel larvae in Lake Lavon on several occasions over the years, but no juvenile or adult zebra mussels have been detected.
Sampling on Lake Fork in November 2015 found one larval zebra mussel at one of seven sampling sites, leading it to be classified as “suspect” along with Lake Ray Hubbard, where a single adult zebra mussel was found in 2011, followed by a detection of zebra mussel DNA in 2014.
Twelve lakes where DNA had been detected in the past have been downgraded to “negative” status for 2016 after a year or more of negative sampling.
Zebra mussels are spread primarily by boats, and regulations cover transport of zebra mussels and movement of water or live bait from one water body to another. Because it is illegal to transport zebra mussels, boats stored on infested lakes must be decontaminated before being moved to another water body — always check your boat and gear for adult mussels after boating on an infested lake.
Boaters statewide are required to drain all water from their boat and on-board receptacles before leaving or approaching a body of fresh water except when moving from one access point to another on the same lake on the same day.
It is important for boaters to remain vigilant about decontaminating their boats. TPWD and a coalition of partners have been working to slow the spread of zebra mussels by reminding boaters to “Clean, Drain and Dry” their vessels before traveling from one lake to another.
More information can be found online at www.texasinvasives.org/zebramussels.
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