Giant salvinia is attacking Texas lakes and rivers. This invasive plant restricts fishing, boating and swimming and causes devastating environmental and economic damage. All it takes is one small piece left on your boat, trailer or gear to infest another lake. Always CLEAN, DRAIN, and DRY before leaving the lake.

Giant salvinia can double in size in less than a week. If left unchecked, it can form mats up to three feet thick that make fishing, boating and swimming nearly impossible. As giant salvinia spreads, it also crowds out native plants that provide food and habitat for local fish and birds.

Giant salvinia is a highly invasive, free-floating aquatic fern. It forms dense mats of folded, quarter-sized green leaves that float on the water surface. The leaves are covered with white, coarse hairs, giving them a velvety appearance.

Texas Parks & Wildlife Department is experimenting with weevils to eradicate salvinia. “What we’re trying to do is raise them in a greenhouse so we can spread them,” said TPWD spokesperson Tom Harvey.

“They reproduce every week, said TPWD fishing tech, Jeff Bowling. “Every eight days or so, they can double in numbers.”

One lake in particular, Sam Rayburn, has about three-and-a-half acres of a salvinia infestation that is so thick there is terrestrial grass growing on the top of the salvinia said Wildlife fishery tech, Mike Gore.

The idea is to have weevils eat the salvinia and then feast on the rest of the salvinia that is spread throughout Texas lakes.

Experts said it takes about 680,000 weevils just to get control over an acre of salvinia. Thirty thousand adult weevils and 90,000 offspring were dumped into a newly discovered affected area on Sam Rayburn Reservoir.

Possession or transportation of giant salvinia in Texas is illegal. Violations are Class C misdemeanors for the first offense, punishable with a fine of up to $500