Wildlife experts battle weed from Brazil

HOUSTON A native of Brazil, giant salvinia (Salvinia molesta) is a floating, rootless fern that can double its coverage area in less than a week. Since it was discovered near Houston in 1998, the plant has spread to 17 Texas lakes, including Toledo Bend, Sam Rayburn, Caddo Lake, Sheldon Lake, Lake Texana and Lake Conroe.

Left unchecked, the plant can choke off boating and fishing access to an entire lake, clog power plant water intakes, and displace beneficial native plants needed by fish. The environmental and economic impact on Texas could be devastating, TPWD experts say.

Giant salvinia has been a serious problem at Sheldon Lake for years, although TPWD has had some success trying to control it with EPA-approved herbicides.

If you spot the fast-growing invasive species, you're asked to let authorities know. You can alert them with an email form at TexasInvasives.org.