Red Tide Mid-Week Update for June 9, 2021

Current Conditions
A patchy bloom of the red tide organism, Karenia brevis, persists in Southwest Florida. Over the past week, K. brevis was detected in 81 samples, with bloom concentrations (>100,000 cells/liter) observed in five samples from Pinellas County, three samples from Hillsborough County, three samples from Manatee County, one sample from Lee County, and three samples from Collier County. Additional details are provided below.

  • In Southwest Florida over the past week, K. brevis was observed at low to medium concentrations in Pinellas County (in eight samples), low to medium concentrations in Hillsborough County (in five samples), background to medium concentrations in Manatee County (in 28 samples), background concentrations in Sarasota County (in three samples), background to medium concentrations in Lee County (in 22 samples), background to medium concentrations in Collier County (in 13 samples), and low concentrations offshore of Monroe County (in 2 samples). Samples collected from Charlotte County did not contain red tide.
  • In Northwest Florida over the past week, K. brevis was not observed.
  • Along the Florida East Coast over the past week, K. brevis was not observed.

In Southwest Florida over the past week, fish kills suspected to be related to red tide were reported in Pinellas, Manatee, Lee and Collier counties. For more details, please visit:

Respiratory irritation suspected to be related to red tide was reported over the past week in Southwest Florida in Pinellas County. For current information, please visit:

Forecasts by the USF-FWC Collaboration for Prediction of Red Tides for Pinellas to northern Monroe counties predict northern movement of surface waters and minimal net transport of subsurface waters in most areas over the next four days.

FWC-FWRI is working closely with the Florida Department of Environmental Protection (FDEP) and other partners on the Piney Point response effort. Status updates and results are posted on the Protecting Florida Together website ( and on the Tampa Bay Estuary Program website (

The next complete status report will be issued on Friday, June 11th. Please check our daily sampling map, which can be accessed via the online status report on our Red Tide Current Status page. For more information on algal blooms and water quality, please visit Protecting Florida Together.

This information, including maps and reports with additional details, is also available on the FWRI Red Tide website. The website also provides links to additional information related to the topic of Florida red tide including satellite imagery, experimental red tide forecasts, shellfish harvesting areas, the FWC Fish Kill Hotline, the Florida Poison Information Center (to report human health effects related to exposure to red tide), and other wildlife related hotlines.

To learn more about various organisms that have been known to cause algal blooms in Florida waters, see the FWRI Red Tide Flickr page. Archived status maps can also be found on Flickr.