Team tracks toxic blue-green algae bloom

The Sanibel-Captiva Conservation Foundation reported that scientists at its Marine Laboratory recently developed an experiment to sample a toxic blue-green algae bloom as it moved from freshwater, to brackish, to saline waters in the Caloosahatchee Estuary

Along with partners from the University of Florida and South Florida Water Management District, the team targeted a visible blue-green algae bloom that had formed near Fort Myers on about July 17

Water samples revealed the bloom as the toxic species Microcystis aeruginosa, which is known to form in nutrient-rich freshwater It was predicted to move downstream toward the Shell Point Retirement Community over a one- to two-week period based on regional bloom transport models previously developed by researchers on the team

“The bloom likely formed due to warmer temperatures and freshwater conditions typical this time of year,” Marine Lab Director Dr Eric Milbrandt said

Additional water samples on July 20 and 24 confirmed that the bloom was at or near where it was projected to be Samples were also taken to a microscopy lab at UF to determine patterns in the shapes of the colonies as the bloom progressed downstream

“Our goal is to understand how the progression of the bloom impacts water conditions in the estuary over time through the production of toxins and release of toxins and nutrients into the water column,” he said

The Marine Lab and UF have been sampling microscopic algae in the Caloosahatchee since 2018 On the first week of every month, they collect water samples from Lake Okeechobee, the Caloosahatchee from the Franklin Lock to Shell Point, and the Gulf of Mexico

“Our results are identifying the drivers of seasonal p h y t o p l a n k t o n b l o o m s t h r o u g h o u t t h e s y s t e m , ” Milbrandt said