ALGAE BLOOM IN LAKE O GROWING QUICKLY
Rapid growth of algae in summer coincides with lower lake levels.
The National Oceanic and Atmospheric Administration estimates 40 percent of Lake Okeechobee is now covered in a harmful bluegreen algae bloom that multiplied quickly in the span of less than two weeks.
Richard Stumpf, a NOAA oceanographer monitoring cyanobacteria, or blue-green algae, on the lake via satellite, said the lake is experiencing a “major bloom.”
It’s not unusual for a bloom to form on Lake Okeechobee in the summer months, but it garners more attention when it coincides with discharges to the St. Lucie and Caloosahatchee estuaries to lower lake levels.
“Last year, there was a large bloom, but they weren’t dropping the water level in the lake at the time and nobody paid any attention,” Stumpf said. “Lake O does get blooms, and this is a big one, but it’s all about timing. This year the timing is bad.”
Satellite images from NOAA’s National Center for Ocean Science from June 9, June 17 and June 20 show increasing concentrations of cyanobacteria in the southwest portion of the lake.
According to the EPA, drinking, swallowing or swimming in water with toxic cyanobacteria can cause stomach, liver, respiratory and neurological problems, as well as rashes. Cyanobacteria can also get so abundant that when they die, the decomposition can remove oxygen from the water and kill fish.
Not all cyanobacteria is toxic, but a handful of samples taken this month have tested positive for very low levels of toxins in amounts not considered harmful by the World Health Organization.
This week, state and federal officials took emergency measures to reduce the amount of discharges to the estuaries by sending more lake water south and out to the ocean.
Stumpf said any harmful algae near an area where water is being discharged from the lake will
travel with it through the system. “The more of the lake it covers, the harder it is to keep it from ending up where you don’t want it,” Stumpf said.
Whi l e there may be a bloom on Lake Okeechobee, the lake is not considered pol- luted or toxic. It is heavy with phosphorus and nitrogen from runoff, which makes it “eutrophic” or rich in nutri- ents. Blue-green algae thrives in high-nutrient water.
Karl Havens, director of Florida Sea Grant at the Uni- versity of Florida, said the southwest area of the lake traditionally sees the most blooms because it is less turbid, meaning more light can penetrate the water column.
“We’ve seen blooms now three years in a row and it might just be a coincidence of the weather, with a lot of rain in the spring and hot days with lots of sunshine,” Havens said. “But it’s not just Mother Nature. It’s the nutrients in the system that were not there before people started to develop the land.”