Red tide monitoring updates from Mote in southwest Florida

Mote Marine Lab scientists continue studying and monitoring the Florida red tide algae, Karenia brevis, along southwest Florida and are encouraging coastal communities to follow online updates. Elevated counts of the algae cells have recently persisted or increased in some Mote-monitored areas.

On Friday, Oct. 16, the statewide red tide update from the Florida Fish and Wildlife Conservation Commission (FWC) said that blooms of the Florida red tide organism, K. brevis, were present last week in, along and offshore of Bay and Gulf counties in northwest Florida, and along and offshore of Manatee and Sarasota counties in southwest Florida. During the week leading up to Oct. 16, K. brevis was detected in background to high concentrations in 12 samples collected in and alongshore of Bay and Gulf counties, and in background to medium concentrations in 27 samples collected in and alongshore of Pinellas, Manatee and Sarasota counties, whereas background to very low concentrations were detected in six samples collected in, along and offshore of Charlotte and Lee counties.

FWC's new mid-week, statewide update should be available shortly at

Oct. 13-20 updates from Mote: some “high” counts near southwest Florida

Results from Mote’s monitoring during Oct. 13-20 continue coming in and will be reflected in FWC’s upcoming statewide reports today and/or Friday, Oct. 21 or 23.  Water sampling results ranged from undetectable to high concentrations of K. brevis in Mote-monitored waters along southwest Florida. Details available to date are summarized below.

When Florida red tide algae cells are present in concentrations elevated above normal “background” levels, people can experience varying degrees of eye, nose, and throat irritation while at the shore or on the water. When a person leaves an area with a red tide, symptoms usually go away. People with asthma, COPD or other chronic respiratory conditions are cautioned to avoid areas with active red tides. Red tide concentrations elevated to low levels can be sufficient to cause respiratory irritation and may also kill fish. Many factors, including algae distribution, currents and winds, can determine whether effects are noticeable.

Blooms of Florida red tide can be very patchy in nature, with background to high concentrations occurring in close proximity to one another. Therefore, effects may be noticeable on one beach but not on a nearby beach.

Oct. 13-14: Offshore survey

Mote scientists collected water samples from the surface, mid-depth and near bottom at multiple stations approximately 10- 50 miles offshore from near the mouth of Tampa Bay south to Captiva Island, and at other stations as conditions warranted.

K. brevis was not detected at most of the sampling stations, and was detected in normal background levels at one. One sample, closest to the mouth of Tampa Bay had "low" counts at surface and mid-depth and "very low" counts at bottom.

On Oct. 14 the researchers encountered discolored water approximately 1.5 miles offshore between Osprey and North Venice and collected water samples at several locations. At one station, surface counts were elevated well into the “high” range. Two other stations also had “high” counts, though less severe, at both surface and mid-depth.
Oct. 19 and 20: Sarasota County shoreline samples

On Tuesday, Oct. 20, red tide algae cells were found in high concentrations and in low concentrations in water samples obtained from two separate docks near Mote’s home base on City Island, Sarasota. Prior to Tuesday, those City Island samples have mostly showed medium concentrations.

Mote continues monitoring for K. brevis by analyzing water samples collected weekly by the Sarasota Healthy Beaches program of the Florida Department of Health from 16 locations along Sarasota County.

Samples from Monday, Oct. 19, showed very low concentrations of red tide algae along Longboat Key and North Lido Beach; low concentrations along the Ringling Causeway and Lido Casino; medium concentrations along South Lido Park, Siesta Beach, Turtle Beach, Nokomis, North Jetty, Service Club Park, Venice Fishing Pier, Brohard Beach, Caspersen Beach and Manasota Beach; and high concentrations along Venice Beach and Blind Pass Beach.
Oct. 21 beach conditions
Mote’s Beach Conditions Reporting System (BCRS, — which provides updates as often as twice daily on certain Gulf Coast beaches — did NOT report dead fish or respiratory irritation among beachgoers at any of the monitored beaches on the morning of Oct. 21. This is likely due to sustained offshore winds over the past several days. However, conditions can change with winds and currents, so beachgoers are advised to continue checking the BCRS when planning their visits to the coast.

Potential respiratory irritation is forecast for some areas in southwest and northwest Florida through Oct. 22 by the National Oceanic and Atmospheric Administration (NOAA), and a new forecast is expected Thursday. (Click here for latest forecasts:

Prior to Oct. 21, extensive fish kills and respiratory irritation were reported through FWC’s Fish Kill Hotline at northwest Florida’s Mexico and Windmark beaches (Bay County; Oct. 13 and 14), as well as Cape San Blass (Oct. 13 and 15), Eagle Harbor (Oct. 15) and Massalina Bayou (Gulf County; Oct. 14-16).  Fish kills and respiratory irritation have also been reported at southwest Florida’s Casey Key Beach (Oct. 14 and 15) and offshore of Venice (Sarasota County; Oct. 16) and offshore of Manasota Key (Charlotte County; Oct. 15) in southwest Florida.

Algae updates and resources

Red tide monitoring in Florida is accomplished through a unique collaboration between FWC’s Fish and Wildlife Research Institute, the Florida Department of Agriculture and Consumer Services (FDACS) and Florida Department of Health, Mote Marine Laboratory, the University of South Florida, county agencies, other private non-profit agencies and citizen volunteers (i.e., the Red Tide Offshore Monitoring Program).

Updates and resources include:

FWC’s statewide red tide status reports (on abundance of K. brevis algae) are updated every Friday afternoon:
Based on statewide results, the National Oceanic and Atmospheric Administration provides forecasts of potential respiratory irritation:
Mote’s Beach Conditions Reporting System provides shoreline observations as often as twice daily:
Red tide background info from Mote and FWC, respectively (including FAQs): and
Red tide and human health – information and multi-lingual rack cards from Florida Department of Health:
FWC’s red tide offshore monitoring program – a way for volunteers to help.
FWC-Mote Facebook page, Florida Red Tide and Other Harmful Algal Blooms:
Trichodesmium (a benign algae that also occurs along the Gulf Coast) information from Mote: