TALLAHASSEE, Fla. -- State wildlife officials are monitoring two red tide blooms along Florida's Gulf coast.
Red tide is a naturally occurring, higher-than-normal concentration of microscopic algae that produce toxins that can affect the central nervous system of fish and marine mammals.
The toxins also can cause respiratory irritation in people onshore or illnesses in people who eat contaminated shellfish.
Alina Corcoran of the Florida Fish and Wildlife Conservation Commission says the blooms have persisted off northwest Florida and southwest Florida since September.
Corcoran says the bloom off southwest Florida has been patchy and less problematic than the bloom off the Panhandle, which has experienced more fish kills and respiratory irritations.
Recreational harvests of hard clams, oysters and mussels are banned during red tides.