Hunter Delz (left) and a worker clean zebra mussels off of a walk-in ramp in Sunrise Beach Village. The area is used daily by Ammo, a black Labrador, to go for a swim. When the dog started cutting his feet on zebra mussels, his owners asked The Mussel Men to scrape the area clean. Photo courtesy of The Mussel Men
Zebra mussel infestations in the Highland Lakes beget more than invasive clusters clogging water intake valves and filters. They also cause health and safety hazards on boats, docks, and ladders, a problem producing new businesses aimed at controlling the damage that these sharp-edged, fast-growing nuisances can do.
Hunter Delz of Kingsland has been working in and around Lake LBJ all of his life. He is one of a select group who can call themselves Kingsland natives, living on land that has been in his family for 75 years. Owner of H.D. Welding, which builds docks on the lake, he’s faced zebra mussel problems for years.
He decided it was time to move some mollusks.
“It’s gotten bad,” Delz said. “They are in every lake from Buchanan on down. They are even in the Llano River.”
Zebra mussels made their way into the United States from Eurasia sometime in the 1980s. Texas officials found the first zebra mussels in Lake Texoma in 2009. The invasive species have since infested 28 lakes in the state, including Marble Falls, LBJ, Inks, Travis, and Buchanan.
Though small individually, zebra mussels form large colonies of tens of thousands, covering dock pilings, boat hulls, and other structures in the water and clogging water systems and filters. Their sharp edges cut through fishing lines and bare feet. Cuts have resulted in stitches and infections.
Delz and business partner Zac Stacy of Lakeway formed The Mussel Men, a service that tackles zebra mussels by scraping them away and either drying them out on land or dropping them in deep water where they can’t survive, the only two ways allowed by the Texas Parks and Wildlife Department. Delz and Stacy offer one-time removal or a monthly maintenance plan to help keep swim and boat areas clean.
What neither they nor anyone else can do is get rid of zebra mussels entirely.
“There is no feasible way to eradicate them from the Highland Lakes,” said Monica McGarrity, senior scientist of Aquatic Invasive Species for the Texas Parks and Wildlife Department. “All we can do is try to take steps to contain them by increasing awareness, to encourage people to clean, drain, and dry their boats.”
The TPWD regulates the disposal of exotic species in Texas. Game wardens enforce the department’s rules and issue citations for what is a Class C misdemeanor when boat owners don’t properly clean their boats between bodies of water.
“It is illegal to transport zebra mussels live or dead attached to a boat,” McGarrity said. “Even if you don’t see them, they have attached. It only takes one boat that’s not cleaned, drained, and dried to go to another lake and cause a new infestation.”
The fine is $500, but McGarrity said game wardens would rather work with boat owners to comply than write citations.
Clean the boat with hot water at 140 degrees, then make sure it has dried completely, she said. Detached zebra mussels can be laid out in the sun to dry and die, but to transport them for disposal off site, they must be tied up in heavy-duty plastic trash bags. TWPD rules as of Jan. 1, 2021, allow for the disposal of bagged, dead zebra mussels in landfills.
For those in the business of removing them from structures in the water, TWPD says to scrape and drop detached mussels in deeper water a distance from the shore. Only those that float back up to the top are able to reattach.
Robert Villarreal Jr., owner of Mussel Boys ATX on Lake Travis, researched the topic extensively before going into business. He explained the counterintuitive idea of leaving the mussels in the water.
“Mussels fall to the bottom of the lake and die there without sunlight,” he said. “Anything beyond 20 feet or so, they have no oxygen and they die.”
He explained that mussels attach to surfaces with byssal threads, rootlike strings of protein that, when cut, can no longer reattach. Dumped in water with no sunlight, they die but leave behind a lot of offspring. One zebra mussel can produce up to 1 million larvae a year, and that’s every single adult mussel, as they all reproduce.
“If you stick your hand in the water and pull it out, you can see zebra mussel larvae,” Villarreal Jr. said. “There are so many it doesn’t make a difference if you remove them from the lake.”
Spicewood entrepreneur Josh Nunn owns Zebra Mussel Pros, which sells Dock Disks, a 7½-inch foam disk that emits a copper-ion cloud mussels don’t like.
“It doesn’t hurt them, it’s not toxic to them, but they don’t like to eat or reproduce in this copper environment,” Nunn said. “It doesn’t get rid of them, but it stops new ones from adhering and the ones that are there from eating and reproducing.”
It is not all that effective in the Highland Lakes because the water moves too much, he said.
“Think of it like a cloud in the sky,” he continued. “A gust of wind moves it on. A copper cloud will move with the water current. They are good with stationary water — good in coves — but not great for a lot of our waterways here in Central Texas.”
In experimenting with the disks, he also discovered they do not last as long as advertised or cover the amount of area promised. The advertised sphere of 8 feet is actually about 4 feet, he said, and rather than lasting six months, they last about four — at least in the Highland Lakes.
“It’s worth a shot though,” he added. “Put it by your swim ladder and see if it works. We were really gung-ho about them at first. They are just not as great with our Texas waterways as we were hoping.”
Research to find more effective solutions is underway, McGarrity said, mostly in suppressing populations in localized areas at water and power facilities. Zebra mussels caused between $300 million and $500 million in damages in 2012 to power plants, water systems, and industrial water intakes in the Great Lakes region alone, according to a study by the U.S. Forest Service and the U.S. Department of Agriculture.
“They’ve only been here since the late 1980s,” McGarrity said. “That’s a relatively short time to develop a silver bullet.”
Both McGarrity and Villarreal Jr. pointed out that zebra mussel populations fluctuate until they reach homeostasis, or equilibrium with the environment around them.
“The population typically peaks in the first one to three years following infestation,” McGarrity said. “Once they hit this high point, they may consume so much of the food resources they eat themselves out of house and home and the population declines. The food source replenishes, they increase again in a boom-and-bust cycle. They can drop off to a lower, steady level.”
But, again, they will not go away. At least not yet.
“Our goal is to keep our lakes clean and enjoyable still, despite the mussels,” Delz said. “I plan to get diver certified so we can do more and reach out to further lakes.”
Until a better solution comes along, hiring some muscle to get rid of mussels can keep swim areas clear during fishing, boating, and swimming season. They will come back, however, but so can the muscle to scrape them away again.