Red Tide Status Update: September 18, 2026

Recent genetic and toxin analyses confirmed that the bloom observed in Northeast Florida in August consisted of Karenia papilionacea, rather than Karenia brevis (the red tide organism).

These two species can be difficult to distinguish using light microscopy alone, so genetic analysis was used to confirm the identification. Karenia papilionacea produces substantially less toxin than K. brevis (if any), and no brevetoxins were detected in Northeast Florida counties during this bloom. The daily sample map was updated with corrected data on September 2, 2026.

Current Conditions
The red tide organism, Karenia brevis, was observed at background concentrations in one sample from Southwest Florida over the past week. We continue to use satellite imagery (USF and NOAA NCCOS) to help track nearshore and offshore conditions. 

Additional details follow.

• In Southwest Florida over the past week, K. brevis was observed at background concentrations in one sample from Sarasota County.
• 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.

No Fish kills suspected to be related to red tide were reported to FWC's Fish Kill Hotline or other partners over the past week.

Respiratory Irritation suspected to be related to red tide was not reported over the past week in Florida. For forecasts that use FWC and partner data, please visit the National Oceanic and Atmospheric Administration’s Gulf Coast Harmful Algal Blooms Forecast.

Short-term (3.5 day) forecasts by the USF-FWC Collaboration for Prediction of Red Tides predict net northwestern movement of surface waters in most areas and variable transport of subsurface waters from Pinellas to northern Monroe counties.

The next status report will be issued on Friday, September 25. 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.