Stay in the know about wildlife, water quality, and ecosystems on Sanibel and Captiva Islands and in Southwest Florida

Red Tide Falls to Background Levels Around Islands

April 27, 2021
The latest red tide update from the Florida Fish and Wildlife Conservation Commission (FWC) indicates that the red tide organism, Karenia brevis, is still present in Southwest Florida, with extensive fish kills reported in Charlotte Harbor.
Click here to watch an NBC-2 news story about the fish kills in Charlotte Harbor featuring SCCF Research Scientist Rick Bartleson, Ph.D.
Over the past week, K. brevis was detected in 40 samples. Bloom concentrations (>100,000 cells/liter) were observed in one sample each from Sarasota, Charlotte, and Collier counties.
For the third week, samples from Lee County and around the islands detected K. brevis mostly at background levels.
In Southwest Florida, K. brevis was observed at background to medium concentrations in Sarasota County, background to high concentrations in Charlotte County, and background to medium concentrations in Collier County.
SCCF Shorebird Biologist Audrey Albrecht didn’t note shorebird issues during her survey of Bunche Beach, but beachgoers were complaining of a large accumulation of red drift algae, she said.
The Clinic for the Rehabilitation of Wildlife (CROW) has reported admitting seven avian patients suffering from Karenia brevis toxicosis in the past week but only one, a double-crested cormorant (Phalacrocorax auritus), survived.
Three other cormorants, an osprey, great blue heron, and brown pelican died. SCCF also documented two deceased loggerheads (Caretta caretta) on Sanibel, though the causes of the deaths have not been established.
Click the button below to learn more about red tide.


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