Tracking blue-green algae blooms to combat toxic bacteria

Satellite images of Lake Okeechobee show how concentrated and where blue-green algae blooms are occurring on the lake. By tracking the algae blooms over time, the data shows how a bloom moves, grows and dies.

The Caloosahatchee Estuary is a bit more difficult because of the size difference in the bodies of water.

The Caloosahatchee Estuary is 27 miles long, transitioning from freshwater to brackish to salt, and stretches from the Franklin Lock to Shell Point. Just as the water flows through the estuary, so does the blue-green algae.

That’s why Eric Milbrandt and other researchers from the Sanibel Captiva Conservation Foundation team are working to track toxic algae blooms.

“We’re really interested in the fate of the Bloom, not only when it’s in its most strong growth phase but also as it moves through the estuary,” said Milbrandt.

Blue-green algae or cyanobacteria, don’t fare well in saltwater, tending to be a freshwater bloom.

“So we want to understand how that impacts the estuary, whether it’s releasing nutrients and toxins, whether it’s still producing toxins as it starts to senesce and die,” said Milbrandt. “Eventually, it’ll sink, which causes decomposition processes, using up oxygen and potentially causing problems for fish.”

Tracking algae blooms in real-time keeps those in Southwest Florida and wildlife safe. Depending on the model, researchers estimate a bloom moves about five miles down the Caloosahatchee every three to four days.

The factors put into those models predict where it goes while tracking wind direction and speed, depth, water flows from Lake Okeechobee, the tides and more into consideration.

“Our plan was always to sample, find the boom, sample it and then come back three or four days later to where it was predicted to be,” said Milbrandt.

The team found a blue-green algae bloom in downtown Fort Myers. They used the models to track it down days later, near Jaycee Park and after a week, tracked the bloom between the Cape Coral Bridge and Shell Point.

“We think we saw the same water mass, if you will, or a patch of water moving down from freshwater mixing with the saltier water in the gulf, in the lower estuary, and it has a negative impact on the bloom, because it’s a freshwater species,” said Milbrandt.

Tracking algae blooms by using helpful technology helps build a cleaner environment sooner.