The Louisiana Department of Wildlife and Fisheries has contracted two days of an aerial herbicide application to control 800 acres of giant salvinia growth on Toledo Bend beginning Thursday, November 29. Efforts will concentrate on shallow backwater areas void of trees, and a follow-up herbicide spray via airboats will address the remaining tree-filled waters and edges of the treatment area.
Giant salvinia is a free floating plant that does not attach to the soil, but instead remains buoyant on the surface of a body of water. It was first discovered on Toledo Bend in 1998 and was the first established population of the plant in Louisiana.
The recent drought and resulting extremely low water levels helped to keep giant salvinia growth at a minimum. However, water levels are beginning to return to normal, providing lots of open water for the plants to reproduce. Backwaters and marsh areas on the extreme north end of the lake contain large quantities of the plant, and changes in wind direction and rain can push the plants out into the main lake where it can reproduce at an alarming rate.
With cooler temperatures moving in, results may be delayed, but the overall effectiveness of the herbicide will not be impacted. Results are expected within three days, but it could take up to three weeks for the plants to completely sink.
None of the herbicides to be used are harmful to lake ecosystems, animal life or humans, and are approved by the EPA. Activities will not be restricted on the lake, but notices indicating the areas to be sprayed will be posted at all boat ramps in the area. Department personnel will also be on hand to ensure no boaters are in the areas to be sprayed.
Image courtesy Louisiana Department of Wildlife and Fisheries