Athens Review, Athens, Texas

July 18, 2013

Invasive species such as Giant Salvinia thrive in area lakes

Rich Flowers
The Athens Review

Athens — The lakes and streams of East Texas are precious resources and citizens are urged to take steps to prevent invasive species from gaining a foothold.

Texas Parks and Wildlife Department Specialist Dr. Richard Ott is especially concerned with zebra mussels that have shown up in the Dallas area and the lower Trinity River.

“They present both an ecological problem, as well as a human health problem in some regards,” Ott said.

The mussels can severely block pipelines used for water transport from the lake to treatment plants. In the Balkan area of Europe, the infestation has required parallel pipelines where one side can be pumping water while giant rotating machines are ridding the pest from the other side. Texas is not equipped for such a development.

The mussels also pose a danger for anyone wading in the water.

“Because the shells on those zebra mussels are so unbelievably sharp, it makes it almost impossible for people to go out and enjoy recreation in a body of water,” Ott said.

The mussels also filter plankton from the watershed, leaving the fish and other aquatic lifeforms nothing for nourishment.

The mussels are transported in a number of ways, in their microscopic, free-swimming life stage called veligers.

“They can be moved very easily in the bilge water of boats, in live wells and wet equipment like life jackets,” Ott said.

The TPWD has instituted a Clean Drain Dry campaign to urge boaters to take precautions before moving from one body of water to the other.

The Giant Salvinia is another species that can take over a body of water and damage it for boaters and fishermen. Lake Caddo and Toledo Bend have had large growths of the species, which can double its biomass in just five days.

“There’s nothing that can survive under these floating mats of Giant Salvinia,” Ott said. “It kills all fish and aquatic life and also ruins the taste of the water.”

Lake Palestine has had reports of the plant on a couple of occasions in recent years, requiring action by TPWD.

“We have had two instances when boaters inadvertently transported it to Lake Palestine,” Ott said. “In both cases, we were advised of that very quickly. We sealed those boat ramps off and for several weeks after collected the material by hand. We were able to stop it both times.”

Because it floats, it’ll move with air currents from one part of the boat to another.

“You can leave a boat ramp in the morning and it’s perfectly clear, then return in the evening and capture them between the bottom of the boat and the boat rails and transport it somewhere else,” Ott said.

The TPWD and other organizations are promoting an Invaders of Texas program in which citizens are trained to spot several different invasive species and report them via the TexasInvasives.com website. Texas Citizen Scientist Workshops are held in various locations around the state which offer classroom training about invasive species, GPS use, digital photography and reporting observations.

A workshop that had been scheduled for the Texas Freshwater Fisheries Center on July 13 was canceled due to a lack of participation. If you are interested in future workshops, check the Texas Invasives website.