Southwest Florida scientists tracking changes in red tide

October 2, 2015
By Marcy Shortuse

mote-60yearsTo the Editor:
Mote Marine Laboratory scientists in Southwest Florida and others along Florida’s Gulf Coast are closely monitoring counts of red tide algae, after noting low-level increases of these algae cells in multiple seawater samples during the past two weeks.
K. brevis, the single-celled, harmful algae that causes Florida red tide, occurs naturally in background concentrations in the Gulf. Recently, some samples in Southwest Florida and the Panhandle have revealed “low” or “very low” counts of K. brevis, which are greater than the normal “background” levels.
Algae are a valuable part of marine ecosystems, producing half of the oxygen we breathe and providing food for marine wildlife. However, harmful algae can be a nuisance or even a health concern.
When K. brevis algae cells accumulate in high abundances, their toxins may affect marine life and people. These toxins can enter the air and cause respiratory irritation among beachgoers, such as coughing, sneezing or a scratchy throat. These symptoms are temporary and often considered an annoyance, but people with asthma, COPD or other chronic respiratory conditions should avoid areas with red tide algae, since the toxins can trigger their symptoms.
Low or very low concentrations of the organism may cause respiratory irritation, particularly if winds blow onshore. Low concentrations also can kill fish. Many factors, including algae distribution, currents and winds, can determine whether the effects are noticeable.
Visit the Florida Fish and Wildlife Conservation Commission’s (FWC’s) red tide status page ( for the statewide red tide status each Friday. Status updates include tables, static maps and interactive Google Earth maps. Mid-week updates are also provided each Wednesday during red tides. Results from the FWC-Mote Red Tide Cooperative Program are included in these updates.
In Sarasota County, beach water is sampled weekly at 16 locations by the Sarasota Healthy Beaches program of the Florida Department of Health and analyzed for K. brevis cells by Mote. Mote scientists partner with FWC through the FWC-Mote Red Tide Cooperative Program to monitor and study K. brevis. In addition, Mote operates the Beach Conditions Reporting System (, which provides daily updates of beach conditions for multiple Gulf Coast beaches.
As of Tuesday evening, Sept. 29, Mote’s Beach Conditions Reporting System was NOT showing respiratory irritation among beachgoers and was NOT showing dead fish along monitored beaches in Sarasota or Manatee counties, or any other participating areas.
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), 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). The Sept. 25 statewide report from FWC includes the water samples collected and/or analyzed by these partners around Florida last week. A brief update will be available Wednesday, Sept. 30, followed by a full report on Friday, Oct. 2 at
Haley Ruger Mote Marine Laboratory & Aquarium Sarasota