Giant Salvinia Detected on Lone Star Lake


AUSTIN – The Texas Parks and Wildlife Department (TPWD) discovered the presence of giant salvinia on Lone Star Lake during a recent fish population survey. This highly invasive plant is fast growing and can be a major threat to aquatic ecosystems.

Members of TPWD’s Marshall District fisheries management team noticed the invasive plant while conducting a routine electrofishing survey on the evening of Oct. 27. Fisheries technicians saw a small amount of giant salvinia in the lights at one of the random sampling sites in the upper end of the reservoir.

“It was fortunate they saw the plants while they were netting fish,” District Fisheries Biologist Tim Bister said. “If they didn’t, it may have gone unreported for weeks or months. The primary infestation is above the bridge where U.S. Highway 259 crosses the lake.”

In order to get a better assessment of the infestation, biologists conducted a full survey of the lake during daylight hours on Oct. 29. They discovered approximately 30 acres of giant salvinia in the far upper end of the reservoir. The Marshall District fisheries management team will work with TPWD’s Aquatic Habitat Enhancement (AHE) team to development and implement a treatment plan to manage this invasive species.

“We had giant salvinia show up in several lakes this year already,” said AHE invasive species biologist Thomas Decker. “I’m surprised it took as long as it did to show up in Lone Star Lake, considering how close it is to the Lake O’ the Pines. We should be able to gain control of giant salvinia on Lone Star Lake quickly, but eradication is unlikely at this point.”

Since June 2020, TPWD has added eight lakes to the list of water bodies currently infested with giant salvinia. TPWD and the U.S. Army Corps of Engineers stepped up giant salvinia management efforts recently on Lake O’ the Pines, as nearly 800 acres of giant salvinia has been treated with herbicides since the end of August.

Giant salvinia, a highly invasive, free-floating aquatic fern that can double in size in less than a week under ideal growing conditions, is one of the major threats to aquatic ecosystems in Texas. The invasive plant produces thick mats making fishing, boating, swimming, and other water recreation nearly impossible.

Boaters need to remove all plants, mud and debris from boats, trailers, vehicles and gear and drain the water from all equipment and on-board receptacles before leaving the lake to prevent giant salvinia and other invasive species from spreading. In addition, boats should be dried completely before visiting another lake, preferably for at least a week. Washing the boat and compartments, using a carwash or other thorough cleaning method, can help to reduce the risk of spreading aquatic invasive species.

On top of the harm these organisms can cause to aquatic ecosystems and the recreational experience at lakes, the transport of aquatic invasive species can result in legal trouble for boaters. Transporting prohibited invasive species in Texas is illegal and punishable with a fine of up to $500 per violation. Boaters are required to drain all water from their boat and onboard receptacles, including bait buckets, before leaving or approaching a body of fresh water.

For more information on how to properly clean, drain and dry boats and equipment, visit the TPWD YouTube channel for a short instructional video. To learn more about giant salvinia, zebra mussels and other invasive species in Texas, visit

TPWD and partners monitor for invasive species in Texas lakes, but anyone who finds them in lakes where they haven’t been found before or who spots them on boats, trailers or equipment that is being moved should help identify and prevent new introductions by reporting the sighting to TPWD at (512) 389-4848 or by emailing photos and location information to


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