Originally Posted by
NCkenner
From a news article:
The good news about managing giant salvinia is that control has been demonstrated without the use of toxic chemicals. In tropical parts of Australia, India, Namibia, Papua New Guinea, and Botswana, introductions of the weevil Cyrtobagous salviniae suppressed populations of this aquatic weed. Eradication of big infestations generally requires the use of commercially available herbicides in addition to biological control organisms. An accidental introduction of the weevil occurred in Florida but on Common Salvinia (Salvinia minima). This interaction proved to be beneficial since Florida has less of an issue with Salvinia minima that other states like Texas and Louisiana. Texas Parks and Wildlife has performed an introduction of 112,000 adult weevils in to B.A. Steinhagen Lake, where Salvinia molesta has taken over hundreds of acres. The weevil has successfully destroyed about 150 acres of the invasive plant. A similar effort is now being performed by the U.S. Fish and Wildlife Service at Caddo Lake on the border of Northwest Teas and Northeast Louisiana.
Maybe you can contact your local management authorities about adding some Weevils?