Texas Parks and Wildlife released the disturbing news Thursday that invasive zebra mussels have been found in Lake Ray Roberts, north of Denton.
Three years ago, the mussels were found in Lake Texoma and have proliferated to such a degree that the lake is unable to be used as a water source for the North Texas Municipal Water District.
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.
“Unfortunately, from an environmental and economic standpoint, this is very bad news,” said Texas Parks and Wildlife Department executive director Carter Smith. “For a host of reasons the implications of this discovery are substantial to Texas waters and their future use and management. We intend to continue working with our partners to do everything reasonably possible to try and prevent the further spread of this harmful invasive species.”
Officials said the species can be spread from lake to lake by boaters who don't properly clean their watercraft between lakes. The TPWD is launching a public education campaign to encourage lake users to clean, drain and dry their boats, trailers and gear. More information is available at http://www.texasinvasives.org.
“More than likely, it was a boat that operated in Lake Texoma or some other lake infested with zebra mussels and then was used in Lake Ray Roberts without first being cleaned, drained and dried,” said Gary Saul, TPWD Inland Fisheries Division Director. “In reality, we’ll probably never know.”
The discovery of the mussels in Lake Ray Roberts came from DNA analysis of the water in 14 North Texas lakes and reservoirs. Twelve of those tests were negative -- while two, Lake Texoma and Lake Ray Roberts, showed positive results. The results of Lake Texoma were expected, but the results found in Lake Ray Roberts were surprising.
"Following receipt of those results, TPWD fisheries biologists conducted a survey of the lake and confirmed the presence of small zebra mussels in several different locations on the lake and immediately below the dam," TPWD said in a news release.
Lake Ray Roberts is only the second lake in Texas found to have zebra mussels and is the first in the Trinity River Basin, TPWD said.
“This is the first confirmed reservoir on the Trinity River Basin to have an established population of zebra mussels,” explained Brian VanZee, TPWD’s regional Inland Fisheries director. “The ones that have been found are only 1/8 to 1/4 of an inch in size, so that means they were likely spawned earlier this year.”
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.