There are fewer of these aquatic invaders in Lake Travis, says Texas Parks and Wildlife

Austin (KXAN) — The Texas Parks and Wildlife Department says the intense heat and low lake levels have lead to a decline in the Zebra mussel population in Lake Travis. However, the threat of spreading the invasive species lingers despite an unlivable conditions for the mollusks.

A viewer sent a message to our ReportIt tip line, asking us to find out why they were seeing fewer Zebra mussels around the lake. They said the usual spots they'd find clusters of the mussels were bare or had only dead mussels present.

According to TPWD, the invasive mussel is present across the state and is known to cause damage to water infrastructure. It was first detected in Lake Texoma in 2009 and can now be found in 33 Texas lakes.

Monica McGarrity, TPWD Senior Scientist for Aquatic Invasive Species, said ongoing drought conditions have caused a dip in Zebra mussels this summer.

She said Zebra mussels have to stay under the water's surface to stay alive. The hot Texas sun evaporating water in the already low Lake Travis and raising the water temperature is making for inhospitable conditions for the mussels.

However, McGarrity said there are likely plenty of Zebra mussels and their larvae under the water's surface. Both of which can be spread by improperly cleaned boats leaving an infested lake and entering one where the pests are not present.

“If a boat is stored in the water in a marina, the boat rises and falls with the water level. So it may still have mussels attached to it. Cooler crevices, things like that, that may not get quite as hot, maybe the mussels don't die off," McGarrity said.

The Lower Colorado River Authority said it is also seeing this trend but seconds that it's crucial to avoid spreading Zebra mussels.

In a statement, the utility said "it's possible the population will rebound when lake levels go back up and cooler weather returns."