Washington Fishing Lake to temporarily close due to discovery of Giant Salvinia

The Wildlife and Freshwater Fisheries (WFF) Division of the Alabama Department of Conservation and Natural Resources (ADCNR) will temporarily close Washington County Public Fishing Lake in southwest Alabama after the discovery of an invasive aquatic plant – giant salvinia – in the lake. The lake will be closed starting August 5, 2024.

One of the most aggressive aquatic plants, giant salvinia is a fast-growing invasive species that has the potential to double in size every two to four days. The plant can quickly take over a pond or lake by forming thick mats on the surface of the water that block sunlight and reduce oxygen levels for fish and other beneficial aquatic plants. Uncontrolled, giant salvinia can overtake aquatic ecosystems and negatively impact outdoor recreation.

Giant salvinia, Salvinia molesta, is an invasive aquatic weed from South America with the potential to do serious harm to U.S. waterways. A free-floating fern, S. molesta was first found in South Carolina in 1995. Giant salvinia has now been observed in 24 watersheds in Texas, California, Arizona, Louisiana, Mississippi, Alabama, Georgia, and Florida. Giant salvinia can successfully winter over in some parts of the United States. Due to their temperate climate, Southern States are more susceptible to salvinia infestation.

The U.S. Department of Agriculture (USDA) listed Salvinia molesta as a noxious weed in 1983. Animal and Plant Health Inspection Service (APHIS) scientists tists are developing a strategy to control giant salvinia using a biological control agent-a host specific weevil originally from southeastern Brazil. Salvinia molesta varies in color from green to gold to brown. It is an aquatic fern with floating, oblong leaves. And, while the leaves of young plants lie flat on the water's surface, the leaves of mature plants grow to be between 1/2 and 1 1/2 inches long (1.27 and 3.8 cm) and are forced upright. A long chain formation occurs as the plants grow together to form mats. Giant salvinia is very prolific and under favorable conditions can double the size of its mats in 7 to 10 days. As the mats continue to grow, they form thick layers of vegetation. Overseas, the layers have grown more than 2 feet thick.

During the closure, WFF Fisheries Section staff will draw down the lake to dry out any giant salvinia around the perimeter of the lake. The drawdown will last through the winter to ensure the exposed plants have been destroyed. Giant salvinia on the lake's surface will also be treated with aquatic herbicide. The lake will remain closed until the giant salvinia has been controlled.

For alternative fishing locations to Washington County Public Fishing Lake, visit http://www.outdooralabama.com/wheretofish or call the WFF Fisheries Section at (334) 242-3471.

ADCNR promotes wise stewardship, management and enjoyment of Alabama's natural resources through four divisions: Marine Resources, State Lands, State Parks, and Wildlife and Freshwater Fisheries. Learn more at http://www.outdooralabama.com.