Texas Parks and Wildlife released news that Tuesday that invasive zebra mussels have been found in Lake Lavon in Collin County.
The presence of live zebra mussels has now been confirmed in six Texas water bodies: Lakes Texoma, Ray Roberts, Lewisville, Bridgeport, Belton, and Lavon.
A team of scientists with the U.S. Geological Survey has been monitoring North Texas reservoirs and rivers for the presence of juvenile and adult zebra mussels as well as for the presence of zebra mussel DNA.
Lake Lavon’s water samples recently tested positive for zebra mussel DNA and a veliger, their larvae, was also positively identified.
The USGS tests also detected zebra mussel DNA in lakes Grapevine, Fork and Tawakoni.
Dr. Robert McMahon, Professor Emeritus of Biology at the University of Texas at Arlington, says that while this news is of concern, he suspects that Lake Fork cannot sustain a zebra mussel population because of low levels of calcium, which the mussels use to construct their shells. He believes that Lake Tawakoni is likely more susceptible.
The finding of zebra mussel DNA in a lake does not necessarily mean that it is infested, but it may indicate that boaters are inadvertently moving zebra mussels or zebra mussel DNA from lake to lake.
The USGS will conduct a follow-up lake survey at Lake Lavon later this month and will resume routine sampling this spring at all area lakes that are currently monitored, which include lakes Texoma, Lavon, Ray Roberts, Ray Hubbard, Lewisville, Grapevine, Fork, Tawakoni and Palestine.
The mussels clog water intake pipes, making it difficult to move water to reservoirs, while also harming boats and motors left in infested waters. Additionally, the sharp edges of the mussel's shell can injure swimmers.
Officials said the species can be spread from lake to lake by boaters who don't properly clean their watercraft between lakes.
The TPWD instituted rules requiring lake users to clean, drain and dry their boats, trailers and gear in 17 Northeast Texas counties. The rules apply to all types and sizes of boats whether powered or not, personal watercraft, sailboats or any other vessel used on public waters.
A proposal to extend the regulation to 30 additional counties in North and Central Texas will be considered by the Texas Parks and Wildlife Commission at its Thursday meeting. Information about the proposed change and a form for online public comment until 5 p.m. Wednesday may be found HERE.
The TPWD said the invasive species originated in the Balkans and was brought to the Americas in the ballast of a ship. They were first spotted stateside in Michigan in 1988 and have since spread to 29 states and more than 600 lakes and reservoirs.
More information is available at http://www.texasinvasives.org.