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

Websites Help Track Red Tide Along SWFL Coast

September 22, 2021

By Rick Bartleson, Ph.D., SCCF Research Scientist

The National Centers for Coastal Ocean Science NCCOS, a division of the National Oceanic and Atmospheric Administration (NOAA), has a new website that helps people see what recent harmful algal bloom (HAB) conditions look like along the coast of Southwest Florida. The site has recent satellite images of chlorophyll for the surface of our coastal waters. Check it out here 

This site also has a map of chlorophyll for Lake Okeechobee here.

NCCOS monitors conditions daily and issues regular forecasts for red tide blooms in the Gulf of Mexico.


SCCF volunteers Lisa Whalen, Sally Wiese, Tom Schmidt, Laurence Schmukler, Mariana Pardo, Robin Christian, Chris Christian, Sue Gillan, Alex Gillan, Chloe Lowman, and Don Lees have been collecting samples for another site with a map that shows HABscope data. This map shows predictions of aerosol brevetoxins for many beaches.  

The NCCOS site also has a link to this interactive map that allows you to zoom in on an area of interest. The warm colors from the satellite are chlorophyll, which may be Karenia brevis (Florida red tide) but could be another type of phytoplankton.

Some people ask if the blooms to our north are coming this way. Though there’s not a steady current, the wind can cause temporary currents that can move patches of red tide this way. USF physical oceanographers have a website that predicts the directions of parcels of water where you can see which direction patches may go for a few days at a time. The lower layer of the water column moves in a different direction than the surface layer in order to balance the sea surface.

The lower map shows the predicted direction of movement of the lower layer of the water column. During cold fronts, as the surface water moves south, the lower layer moves inshore and upwells to replace the surface water. This lower layer water sometimes has bloom concentrations of Karenia.

We have been having a relatively HAB-free summer on Captiva and Sanibel. The water at the East End beaches may look reddish, but that’s from high runoff of rain water full of tannins from surface runoff.


Archives by Month