State health officials are warning red tide is in Gulf waters near south Marco Beach and many Naples beaches.
Officials urge beachgoers to be cautious if they have health issues.
The other beaches include Clam Pass, Barefoot Beach , Wiggins Pass, Naples Pier, Barefoot Beach State Preserve , Vanderbilt Beach , and Seagate, according to the state Department of Health.
Dead fish were reported at the beach at Wiggins Pass, which can worsen respiratory distress for some people, according to DOH.
There are no reports of red tide along the shoreline of Lee County or its barrier islands of Sanibel and Captiva.
Tests conducted Jan. 6 based on water samples confirmed red tide at the beach locations.
Red tide is caused by high concentrations of a toxin-producing microscopic algae, called K. brevis, that is found in the Gulf of Mexico.