CALCASIEU PARISH, LA — Lake Charles residents can expect to see some relief in the presence of giant salvinia on the Calcasieu River thanks to environmental factors in combination with Louisiana Department of Wildlife and Fisheries’ control efforts.
Increased salinities on the Calcasieu River are taking a toll on giant salvinia growth on the water body. A wetter than usual spring caused a decrease in salinity levels, creating an environment more conducive for plant growth. However, conditions are returning to normal, and a recent boat assessment revealed that most of the plants below the saltwater barrier are dead or dying. Allowing salinity to kill the salvinia proves to be the most cost-effective method in achieving maximum control of the plant. With that in mind, the Department is focusing their control efforts on the upper end of the river.
Areas above the saltwater barrier, including the West Fork, have also shown signs of minimal growth, with only scattered plants observed at some locations. Weevils were heavily stocked in these areas through the Department’s weevil stocking program. Weevil damage was observed in these areas and adjacent public waters. This evidence of weevil activity on the plant is encouraging for future control.
LDWF will continue to monitor the plant, particularly in places with lower salinities, and herbicide treatments will be made on public waterways as needed to maintain control of the plant throughout the year.