A large-scale red tide bloom, roughly 100 square miles in size, is floating in the Gulf of Mexico about 25 miles off the Southwest Florida coastline, stretching from Charlotte Harbor to beyond Marco Island. Scientists say the bloom started in Tampa Bay after Hurricane Milton and has been slowly drifting south, fueled by nutrient-rich storm runoff.
"When I see pictures like that, one of the first things I think of is runoff from land,” said Michael Parsons, from Florida Gulf Coast University (FGCU).
Satellite images from the National Oceanic and Atmospheric Administration and photos shared by the Calusa Waterkeeper show just how massive this bloom is — closer to 115 square miles, by some estimates.
“The patch has slowly grown and moved more south. Now, it appears to stretch from Sanibel down to Naples,” said Eric Milbrandt, with the Sanibel Captiva Conservation Foundation.
The bloom has mostly stayed offshore but, in patches, has segmented and caused recent red tide advisories across Southwest Florida.
“The bloom has been sitting offshore for the most part, but we’ve seen fingers of the bloom work their way in,” said Parsons.
There are no health advisories in place yet between Charlotte Harbor and Marco Island, according to the Florida Department of Health.
“It takes time for scientists to collect samples, get them under a microscope, and analyze them. I expect an advisory could be issued if high concentrations are found,” said Milbrandt.
Red tide blooms are toxic to marine life and can create a domino effect: dead fish on beaches, wildlife strandings, and even respiratory problems for people near the shore.
“I hate to say it, but it is typical — and it’s becoming more frequent,” said Milbrandt.
Whether or not the bloom will impact our coast is in the hands of nature. Gulf currents and winds can contribute to red tide effects.
“We don’t really have a crystal ball looking that far forward,” said Parsons.