Red Tide Current Status

FWC reports on the current status of Karenia brevis blooms using tables, static maps, and interactive Google Earth maps. Archived status maps can be found in our Flickr gallery.

Midweek Red Tide Status Update (April 25, 2018)

A bloom of the Florida red tide organism, Karenia brevis, persists in Southwest Florida.

In Southwest Florida over the past week, K. brevis was observed at background to low concentrations in four samples collected from Charlotte County, background to medium concentrations in twenty-two samples collected from and offshore of Lee County, very low to high concentrations in fifteen samples collected from and offshore of Collier County, and very low concentrations in two samples collected from and offshore of Monroe County.

Additional samples collected throughout Florida over the past week did not contain K. brevis.

Over the past week, fish kills were reported in Southwest Florida in Lee County (at Bonita Beach, Fort Myers Beach, Gasparilla Island, Lighthouse Beach, Lovers Key State Park, Lynn Hall Beach Park, Newton Park and Tarpon Bay) and Collier County (at Barefoot Beach, Clam Bay, Gordon Pass, Seagate Beach, and Vanderbilt Beach). Respiratory irritation was reported over the past week in Lee County (4/20 -  4/21, and 4/24 at Bonita Beach; 4/19 and 4/22 at the Causeway Islands; 4/18 – 4/19 and 4/21 – 4/24 at Lovers Key; 4/19 and 4/22 – 4/24 at Newton Park) and Collier County (4/17 and 4/19 – 4/24 at Barefoot Beach; 4/23 at Clam Bay; 4/24 at Seagate Beach; 4/24 at South Marco Beach; 4/19 and 4/24 at Vanderbilt Beach).

Forecasts by the USF-FWC Collaboration for Prediction of Red TidesExternal Website for Pinellas to northern Monroe counties predict net southern movement of surface waters and southern, onshore movement of subsurface waters over the next three days.

Midweek Red Tide Update Map (April 25, 2018)

Southwest Coast Red Tide Counts April 17 through 24, 2018
View a larger map Adobe PDF (PDF 277KB) (April 25, 2018)

Red Tide Status Report (April 20, 2018)

A bloom of the Florida red tide organism, Karenia brevis, persists in Southwest Florida.

In Southwest Florida over the past week, K. brevis was observed at background concentrations in one sample collected from Manatee County, low concentrations in one sample collected from Charlotte County, background to medium concentrations in 10 samples collected from Lee County, and background to low concentrations in nine samples collected from Collier County.

In Northwest Florida over the past week, K. brevis was observed at background concentrations in three samples collected from Bay County and one sample collected from Gulf County.

Additional samples collected throughout Florida over the past week did not contain K. brevis.

Over the past week, fish kills were reported in Southwest Florida in Lee County (Bonita Beach, Causeway Islands, Ft. Myers Beach, Knapps Point, Nerita Beach, Sanibel Beach, Gasparilla Island, Lighthouse Beach, Lovers Key, Newton Park, and Tarpon Bay) and Collier County (Barefoot Beach and Vanderbilt Beach). Respiratory irritation was reported over the past week in Lee (4/13 -  4/14 at Bonita Beach; 4/19 at Lynn Hall Beach Park) and Collier (4/14, 4/16 – 4/17, and 4/19 at Barefoot Beach; 4/16 at South Marco Beach; 4/19 at Vanderbilt Beach) counties.

Forecasts by the USF-FWC Collaboration for Prediction of Red TidesExternal Website for Pinellas to northern Monroe counties predict minimal net movement of surface waters and southern, onshore movement of subsurface waters over the next three days.

Red Tide Status Map (April 20, 2018)
Statewide Red Tide Counts April 12 through 19, 2018
View a larger map Adobe PDF (PDF 278KB) (April 20, 2018)

Regional Status Reports and Maps (April 20, 2018)

Southwest coast report Adobe PDF (PDF 210KB) and map Adobe PDF (PDF 289KB)
East coast report Adobe PDF (PDF 50KB) and map Adobe PDF (PDF 419KB)
Northwest coast report Adobe PDF (PDF 48KB) and map Adobe PDF (PDF 482KB)

To see detailed information on this week's samples, view the current Statewide Google Earth map for April 20, 2018External Website. 

By using Google Earth, you can zoom in to specific locations and click on stations to see detailed information, including sample date and cell concentration. You must have Google Earth installed on your computer to view this map; the software can be downloaded from the Google Earth websiteExternal Website

The FWRI Red Tide Status Line is now available to callers throughout the state. FWRI updates the recording each Friday by 5 p.m. Red Tide Status Line: 866-300-9399 (toll-free inside Florida only); 727-552-2448 (outside Florida).

Reports are updated on Friday afternoon except during holidays, in which case the report will be released on the closest day. Additional information, if available, is provided on Wednesday afternoon. To receive an e-mail when the current status has been updated, visit our subscription area.

FWC's Red Tide Action Report

Red tide is a naturally-occurring microscopic alga that has been documented along Florida’s Gulf Coast since the 1840’s and occurs nearly every year. Blooms, or higher-than-normal concentrations, of the Florida red tide alga, Karenia brevis, frequently occur in the Gulf of Mexico. Red tide begins in the Gulf of Mexico 10 to 40 miles offshore and can be transported inshore by winds and currents.

FWC Actions and Partnerships:

  • FWC operates the toll-free fish kill hotline. To report fish kills, contact the FWC Fish Kill Hotline at 800-636-0511 or submit a report online. Reports from this hotline help FWC researchers track and better understand the impact of red tide in Florida.
  • FWC remains available to local agencies and partners in affected areas, including area business and tourism groups in southwest Florida. Any local agency or group that has any questions or concerns can contact Kelly Richmond from the FWC at 727-502-4784.
  • FWC continues to partner with the Florida Department of Health to advise residents and visitors of any potential health impacts. Residents and visitors can contact the DOH’s aquatic toxin experts at 850-245-4250 or contact their local health department for any concern about health safety.
  • FWC’s Fish and Wildlife Research Institute and Mote Marine Laboratory work together to monitor Karenia brevis. This cooperative effort is designed to help mitigate the adverse impacts of red tide. This joint research program that includes red tide monitoring, research and public outreach and education has resulted in better tools and ongoing monitoring for red tides along the Gulf Coast.
  • In partnership with the FWC, the Collaboration for Prediction of Red Tides (CPR) at the University of South Florida offer a new Harmful Algal Bloom (HAB) tracking tool that generates a 3.5-day forecast of the bloom trajectories.
  • To protect public health, FWC’s Fish and Wildlife Research Institute’s Harmful Algal Bloom (HAB) group closely monitors the status of K. brevis on Florida’s coasts, providing technical support to the Florida Department of Agriculture and Consumer Services (FDACSExternal Website), the agency that regulates approved shellfish harvesting areas.  
  • Since 2000, FWC’s Fish and Wildlife Research Institute established a Red Tide Offshore Monitoring Program, which is a volunteer program for citizens to help collect water samples from routine collection points and sites reported for suspected harmful algal blooms (HABs).The timely sampling by volunteers allows researchers to provide an early warning of offshore algal blooms and investigate reported events as they occur. The Program needs volunteers to collect samples from all coastal Florida counties. To view more information visit, Red Tide Offshore Monitoring Program or use the Volunteer SignUp Form.

Red Tide Resources

Previous Regional Status Reports and Maps

April 13, 2018
Southwest coast report Adobe PDF (PDF 219KB) and map Adobe PDF (PDF 275KB)
East coast report Adobe PDF (PDF 39KB) and map Adobe PDF (PDF 415KB)
Northwest coast report Adobe PDF (PDF 50KB) and map Adobe PDF (PDF 480KB)
Google Earth mapExternal Website

April 6, 2018
Southwest coast report Adobe PDF (PDF 115KB) and map Adobe PDF (PDF 313KB)
East coast report Adobe PDF (PDF 59KB) and map Adobe PDF (PDF 417KB)
Northwest coast report Adobe PDF (PDF 58KB) and map Adobe PDF (PDF 482KB)
Google Earth mapExternal Website

March 30, 2018

Southwest coast report Adobe PDF (PDF 224KB) and map Adobe PDF (PDF 261KB)
East coast report Adobe PDF (PDF 46KB) and map Adobe PDF (PDF 291KB)
Northwest coast report Adobe PDF (PDF 54KB) and map Adobe PDF (PDF 482KB)
Google Earth mapExternal Website

March 23, 2018

Southwest coast report Adobe PDF (PDF 239KB) and map Adobe PDF (PDF 408KB)
East coast report Adobe PDF (PDF 55KB) and map Adobe PDF (PDF 416KB)
Northwest coast report Adobe PDF (PDF 41KB) and map Adobe PDF (PDF 484KB)
Google Earth mapExternal Website

Additional archived status maps can be found on FlickrExternal Website

Key for Results

DescriptionKarenia brevis cells/literPossible Effects (K. brevis only)
NOT PRESENT - BACKGROUND background levels of 1,000 cells or less None anticipated
VERY LOW >1,000 to 10,000 Possible respiratory irritation; shellfish harvesting closures > 5,000 cells/L
LOW >10,000 to 100,000 Respiratory irritation, possible fish kills and bloom chlorophyll probably detected by satellites at upper limits
MEDIUM >100,000 to 1,000,000 Respiratory irritation and probable fish kills
HIGH >1,000,000

As above plus discoloration


Hotlines and Information Sources



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