red tide away
Eastern winds have been a blessing for Sarasota and Charlotte counties, blowing a red tide algae bloom south that plagued Englewood and other coastal communities the past few weeks.
Due to the winds, surface concentrations are being blown south out of Sarasota and Charlotte counties into Lee County and could end up in the Florida Keys, FWC researcher Alina Corcoran said. However, Corcoran cautioned red tide may still be found in the water column offshore and samples continue to show varying concentrations of the algae.
The silver lining in the recent red tide bloom is that it’s been aiding Mote Marine Laboratory’s ongoing research.
“This is an opportunity to use a moderate natural bloom of red tide algae and look closely at the response to added nutrients and combinations of nutrients,” said Mote researcher L. Kellie Dixon, who manages Mote’s Chemical and Physical Ecology Program.
Since 2007, Mote researchers have been studying the response of red tide algae to nutrients.
“(Red tide) is not the least bit picky,” Dixon said, explaining how other algae, by contrast, are often limited in how they draw nutrients from water.
According to a recent Florida Fish and Wildlife Conservation Commission report, a patchy bloom of the red tide algae —Karenia brevis — has extended from southern Pinellas through Collier counties.
According to an FWC report Friday, very low to medium concentrations of red tide were found alongshore Manatee south to southern Collier counties. Samples collected in lower Tampa Bay (Pinellas and Manatee counties) and northern Pine Island Sound (Lee County) showed background to medium concentrations.
Researchers deem the background presence of red tide as levels of 1,000 cells or fewer per liter of water. Very low counts are more than 1,000 cells to fewer than 5,000 cells per liter. Red tide can cause fish kills and respiratory irritations when levels exceed 100,000 cells or more of the algae concentrated in a liter of water.
The blooms generally first blossom 11 to 45 miles offshore, but researchers haven’t identified what first triggers them. According researchers, winds and currents drive red tide ashore. Toxins are generally released when the delicate algae cells break up due to wave action.
Mote researchers have been able to grow red tide algae, but Dixon said the “wild” algae from water samples collected in Tampa Bay, Charlotte Harbor and the Caloosahatchee River appear more opportunistic in their ability to absorb nutrients.
Mote expects to complete its comprehensive analysis within six months.
The public is encouraged to report red tide conditions or any other fish kills to the FWC hotline at 800-636-0511. Call 866-300-9399 to hear recorded reports of red tide throughout the state, or go to www.myfwc.com/research/redtide.
Mote tracks red tide in Manatee and Sarasota counties. Mote also posts beach conditions for 25 public beaches at www.mote.org/beaches.