Red tide will likely weather cold front
A strong cold front that's working its way through Florida has scientists wondering if the system is strong enough to impact red tide sitting offshore and along beaches.
This red tide bloom started in October with a few small patches, but has grown so large that it can be detected by satellites, and it stretches from Manatee County to the south Lee County border.
"We have had times in the past when a big, strong cold front did away with our red tide," said Rick Bartleson, a water quality scientist at the Sanibel-Captiva Conservation Foundation on Sanibel. "But the cold weather alone won’t do it this time because our water temperatures are still up."
Temperatures this week are expected to plummet into the 30s, according to various weather forecasts.
Red tide is a naturally occurring organism that feeds on coastal nutrients.
Blooms have been recorded here for hundreds of years, but many water quality scientists say the blooms may be more frequent and stronger in modern times because of excess nutrients washing off the landscape and coming from Lake Okeechobee.
The Florida Fish and Wildlife Conservation Commission will issue its next red tide report Thursday.
Strong outbreaks cause fish, marine mammal and sea turtle kills and can cause respiratory issues in humans when cells reach 10,000 cells per liter, and counts along the Southwest Florida coast have been at 1 million cells per liter and higher in recent weeks.
Although the organism is water-based, waves can cause the toxins to become airborne.
SCCF reported water temperatures of 63 degrees Tuesday at Fort Myers Beach, which is still warm enough for the organism to thrive.
"Red tide can thrive throughout the year. They do become stressed as waters dip below 60 degrees, however, waters are above that point currently," said Tracy Fanara, a red tide expert at Mote Marine Laboratory in Sarasota. "(So most of the) effects are dependent on currents and winds."
Fish kills have been reported in Lee, Sarasota and Manatee counties in recent weeks, but most of the dead fish appear to be offshore — where the bloom numbers are highest.
Bartleson said the weather will have some type of impact on the bloom, but exactly what conditions will be like a week from now are still unknown.
"The wind and the waves are definitely having an effect that will move the red tide around," he said. "And the cells are fragile and some of them will break in the waves, and that will cut down on the number of cells as long as they’re not replenished from below."
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– 1844: First documented red tide outbreak
– 11: Months in duration for 2005 event
– 10,000: Cells per liter can cause fish kills and respiratory issues in humans, sea turtles and marine mammals
– 65: Feet deep the state can monitor for presence of organism
– 20: Million cells per liter measured off Sanibel in recent years
Sources: Florida Wildlife Research Institute, Florida Fish and Wildlife Conservation Commission, The News-Press records, Sanibel-Captiva Conservation Foundation