The recent cold fronts that passed through Louisiana resulted in prolonged periods of sub-freezing temperatures, and single-digit temperatures in some areas. While these extreme conditions had many devastating effects on our state, they will also result in a reduction of aquatic weeds across the state.
The Louisiana Department of Wildlife and Fisheries (LDWF) is currently evaluating impacts of the freeze on aquatic vegetation coverage statewide and will continue this assessment as we move into the spring. The extent of this impact will not be known for several weeks, as consistently warm water temperatures are needed for the dead plants to decompose and drop from the water surface. Some plants will continue to float and remain green temporarily, but many will eventually die, break down and sink.
Aquatic weeds, such as giant salvinia and water hyacinth, are two of Louisiana’s “invasive species” – organisms that cause ecological and/or economic harm when found in areas where they are not native. This aquatic vegetation can multiply quickly and become incredibly dense, inhibiting access to waterways and shading out native vegetation.
The best way to control the impacts of invasive species is to control their spread. However, this can be challenging as aquatic vegetation is easily spread from one waterbody to another because it tends to cling to objects such as boat trailers. To help limit the spread of invasive species, the department encourages boaters to be diligent with cleaning boat trailers after a day on the water.
When springtime weather returns, the public can request LDWF assistance for areas with green, actively growing aquatic vegetation at www.wlf.louisiana.gov/page/controlling-aquatic-plants-and-enhancing-freshwater-habitat, then click on “Request Assistance with Invasive Aquatic Vegetation.” LDWF uses various methods to combat undesirable aquatic vegetation, including drawdowns, herbicide spray treatments and biological control such as salvinia weevils.