It’s been about a year since zebra mussel DNA was confirmed in Lake Bridgeport.
The old saying, “Where there’s smoke, there’s fire” has proved true again, as adult zebra mussels have now been found in the lake.
Recently, a diver scouring the bottom of the lake for freshwater mussels native to Texas waters hauled in more than he bargained for. According to Texas Parks and Wildlife Department fisheries expert Bruce Hysmith, attached to his catch were thumbnail-sized zebra mussels.
Zebra mussels cause environmental and economic damage. Some of the most pressing concerns are over community water supplies. The mussels can clog water intake pipes and other machinery necessary to keep the taps flowing.
Lake Bridgeport, owned and operated by the Tarrant Regional Water District, supplies much of Wise county’s drinking water. The reservoir is also used to store water for other lakes downstream, although it has been about a year since TRWD has allowed water from Lake Bridgeport to flow downstream.
TRWD’s Engineering Services Director, David Marshall, said the discovery of adult zebra mussels is unnerving – but it is still early and Lake Bridgeport might not suffer as much as other area reservoirs.
“Lake Ray Roberts has the highest population in Texas, higher even than Lake Texoma,” Marshall said. “We are not sure why there is such a difference between Texoma and Ray Roberts, but we could see conditions like Texoma in Lake Bridgeport.”
Since Lake Bridgeport’s flow goes down the Trinity into Eagle Mountain Lake, it’s likely that reservoir, too, will be impacted. Zebra mussel DNA has already been detected in Eagle Mountain.
Marshall said TRWD has been working with water experts from the northeast, as they have more experience dealing with this species. The consensus is that, because Lake Bridgeport gets warmer than many other reservoirs, zebra mussel growth could be curbed naturally.
“We try to monitor what kind of population there is and right now we have very low population,” Marshall said. “We still have to be vigilant in our maintenance.”
Marhsall said zebra mussels typically affect things like low-flow control valves and intake screens. He said TRWD brings divers in twice a year to inspect, clean and maintain their equipment to avoid costly problems.
This is also a concern for local entities that draw from the reservoir. Decatur Public Works Director Earl Smith said his department might even use closed-circuit cameras to monitor the city’s intake system.
“We can drop them in to see the structures which should be clean,” Smith said. “If the zebra mussels start multiplying, they’ll plug those pipes up.”
WHAT’S THE BIG DEAL?
Zebra mussels, which first came into the United States via shipping in the Great Lakes, are a destructive, invasive species that spreads via fishing boats and trailers. They are only about 1- inches long and are clearly distinguished by their zebra-striped shells.
The shells are sharp and pose a danger to swimmers. An abundance of the mussels can also affect water taste and quality.
According to www.texasinvasives.org, zebra mussels are present in Lake Texoma, Ray Roberts, Lewisville, Bridgeport, Lavon and Belton. Evidence of the mussels has also been found in Lake Ray Hubbard, Grapevine, Lake Fork, Takwoni, the Red River below Lake Texoma, the Elm Fork of the Trinity River, and Sister Grove Creek.
In an effort to prevent the spread of the mussels, the state requires anglers and boaters to drain all water from their vessels – including live wells, bilges, motors and other receptacles – on approaching or leaving a body of water.
That law went into effect July 1, and Texas has made possession or transportation of zebra mussels a Class C misdemeanor for the first offense, punishable by a fine of up to $500. Repeat offenses can be a Class B misdemeanor, punishable by a fine of up to $2,000, and jail time up to 180 days.
One zebra mussel can produce up to 1 million larvae, invisible to the naked eye.