OKEECHOBEE — As the summer heat continues, the lake remains below 12 feet above sea level, and blooms of algae and cyanobacteria (called blue green algae, although it is not actually algae) are common. The heat combined with little movement of water create conditions conducive to the rapid reproduction of the microscopic organisms into “blooms.”
The National Oceanographic and Atmospheric Administration most recent satellite imagery, from July 15, shows a concentration of cyanobacteria on the west and north shores of the lake. The NOAA images can not determine what species of cyanobacteria is present. NOAA images cannot tell if the cyanobacteria is producing any toxins. United States Geological Survey tests indicate there are at least 28 different species of cyanobacteria in the Lake Okeechobee Waterway, which includes the Caloosahatchee River and the St. Lucie River as well as the big lake. Of those, about 25% of the species of cyanobacteria are capable or producing toxins. Cyanobacteria that are capable of producing toxins do not always do so.
You cannot tell whether a green mass on the surface of the water is algae or cyanobacteria by just looking at it, according to the NOAA website. NOAA uses computer imagery to turn satellite data, which uses a spectrum of light not visible to the human eye, to predict areas of cyanobacteria concentrations. Areas in red or orange are more likely to have visible algae on the water surface. Areas in green or yellow may have cyanobacteria in the water column that is not visible from the surface.
Cyanobacteria is moved by wind or water current. Cyanobacteria can also move up and down in the water column by inflating and deflating gas vesicles.
The Florida Department of Environmental Protection encourages everyone in Florida to report algal blooms online at https://floridadep.gov/AlgalBloom or by calling 855-305-3903. When an algal bloom is reported FDEP takes samples to determine what kind of cyanobacteria — if any — is present, and if there are any toxins present.
To report a fish kill, call Florida Fish and Wildlife Conservation Commission at 800-636-0511.
• An algae bloom reported July 15 near the Canal Point recreation area on Lake Okeechobee was sampled by FDEP. It was determined to be mixed algae, no dominant species.