The discovery of a fast-growing invasive plant has required temporary closure of the Washington County Public Fishing Lake, the Alabama Department of Conservation and Natural Resources said.

Giant salvinia, a free-floating fern native to Brazil, is one of the most aggressive aquatic plants and has the potential to double in size every two to four days, according to the Wildlife and Freshwater Fisheries Division of the ADCNR.

Giant salvinia forms thick mats on the surface of the water that block sunlight and reduce oxygen levels for fish and beneficial aquatic plants. Giant salvinia can overtake aquatic ecosystems and interfere with outdoor recreation, the ADCNR said.

The Washington County Public Fishing Lake is now closed until further notice.