SARASOTA COUNTY — Red tide has reappeared in Sarasota County, but at very low levels, according to Sarasota County’s Florida Department of Health.
Water samples taken Monday and reports of respiratory irritation prompted health officials to place signs at some beaches in the North Jetty area of Longboat Key over the weekend.
Experts believe the current conditions were not caused by polluted water released from Piney Point in Manatee County earlier this month. On the contrary, the bloom seems to have emerged from Charlotte and Lee County starting in December. Southerly winds pushed the bloom north to Sarasota County.
“It’s not a complete surprise to us at this time,” said Cindy Heil, director of the Mote Marine Laboratory’s Red Tide Institute.
Over the past week, Karenia brevis, a naturally occurring toxic algae known as red tide, has been detected in 54 samples in southwest Florida, according to the Florida Fish and Wildlife Conservation Commission.
Concentrations of flowers were observed in a sample from Sarasota, Charlotte and Collier counties. Red tide was also observed at background concentrations in a sample from northwest Florida.
Red tide was observed at background to medium concentrations in and off Sarasota County in 31 samples and at very low to high concentrations in Charlotte County in four samples. Samples from or off Pinellas, Hillsborough and Manatee counties did not contain red tide.
“The winds have been consistently southerly over the past week and as a result the red tide cells that were south of us are moving north,” said Dr. Robert Weisberg, professor of oceanography at the University of South Florida. “That’s why there are higher concentrations in Sarasota. We need a front to get through and for the winds to shift to the north; but, alas, that’s not in the weather forecast.
Weisberg and University of South Florida researchers use a computer model that predicts the path of nutrient-rich sewage dumped into Tampa Bay from the former Piney Point fertilizer plant this month as they study how polluted water affects marine ecosystems.
Related:USF model shows path of polluted discharge water from Piney Point as it spreads around Tampa Bay
Weisberg said it doesn’t appear the conditions in Sarasota County were caused by the 215 million gallons of nitrogen-laden water spilled from the Piney Point phosphate industrial site earlier this month. He also said it’s too early to tell if the path of the polluted discharge water could impact the red tide in the Gulf.
“We shouldn’t be alarmists,” Weisberg said. “Southerly winds are holding things up in Tampa Bay, so concentrations are not a factor in Sarasota Bay right now.”
The last major outbreak of the microorganism that turns the turquoise waters of the Gulf the color of cola lasted from October 2017 to February 2019. It killed countless sea creatures, including dolphins, sea turtles and manatees.
Algae can be fed near shore by nutrient pollution associated with urban or agricultural runoff, according to Mote Marine Laboratory.
Wave action can break down red tide cells, releasing toxins into the air, leading to respiratory tract irritation.
More coverage:Researchers publish manual to fight red tide, other deadly algae
As of Friday morning, Mote’s Beach Conditions reported no sightings of killed fish along the county’s 35 miles of shoreline.
Experts cannot predict the severity of this red tide bloom, said Heil, director of the Mote Marine Laboratory’s Red Tide Institute.
However, the evidence so far points to this year being a “pretty normal red tide year,” Heil said.
“It’s been ups and downs over the past four months,” Hail said. “It changes from week to week but it’s nothing like the 2018 bloom at the moment.”
Water samples taken earlier this week show the highest concentration of Karenia brevis cells in the region is at Siesta Key Beach. The level there is medium, which means that some people may experience respiratory irritation.
Scot Ruberg, lifeguard of the Siesta Key public beach, known by his beach name, “Scooter,” has been giving cheerful morning reports for years on his Facebook page.
As for Friday morning: “I look at the beautiful Gulf of Mexico… and is it discolored? No,” Ruberg said. “Are there any dead fish washed up on the shore from the red tide? No, there is no dead fish to wash.
Ruberg noted mild breathing issues, but said that didn’t cause anyone to leave the beach Thursday night.
“Grab your gear and get down and let’s play this day to day,” Ruberg said. “It’s sunny today and there’s no reason not to go down to the beach.”
Is the red tide harmful to humans?
Some people may experience mild respiratory symptoms such as eye, nose and throat irritation similar to cold symptoms. Some people with breathing problems sometimes experience more severe symptoms. Usually the symptoms disappear when a person leaves the area or goes inside.
Health officials recommend that people with symptoms caused by the red tide stay away from beaches or go to an air-conditioned space.
Which Sarasota County Beaches Could Be Affected by Red Tide?
Signs were posted Friday at the following beaches:
- Rowboat key
- Bird Key Park (Ringling Causeway)
- Lido North Beach
- Lido Casino
- South Lido
- Siesta Key Beach
- Turtle Beach
- Nokomis Beach
- North Pier Beach
Current beach conditions can be checked on the Mote Marine website, visitbeaches.org.
Sarasota County health officials also post weekly sample results to ourgulfenvironment.net.
Timothy Fanning covers the Sarasota government for the Herald-Tribune. Contact Timothy at [email protected] or on Twitter: @timothyjfanning. Support the Herald-Tribune by subscribing today.