Mote Marine notes presence of red tide in Southwest Florida since late 2020; situation unrelated to Piney Point discharge
A sound residents and visitors alike prefer not to hear returned to Siesta Beach this week, The Sarasota News Leader learned: the “red tide cough.”
In its early afternoon Beach Conditions report on Sunday, April 11, Mote Marine Laboratory noted that the water color at Siesta Beach was dark, respiratory irritation was moderate, and “Many” dead fish had been found.
The wind was out of the north, the report added.
However, late on the morning of April 12 at Englewood Beach, with the wind out of the west-northwest, no respiratory irritation was reported, and the water was clear.
In response to a News Leader inquiry about the Siesta situation, Sarasota County Media Relations Officer Drew Winchester wrote in an April 13 email that the Parks, Recreation and Natural Resources staff has been tracking the presence of red tide in the Gulf of Mexico, “but we haven’t had any major effects or impacts on our beaches. There have been some mild aerosols due to onshore winds, but that’s it so far.”
The aerosols associated with red tide are responsible for the cough, medical experts have noted.
Then, on April 15, the Florida Department of Health in Sarasota County (DOH-Sarasota) issued an advisory about elevated red tide along the county coast, based on water samples taken at the beaches on April 12, the department said.
“Some people may have mild and short-lived respiratory symptoms such as eye, nose and throat irritation similar to cold symptoms,” the advisory pointed out. “Some individuals with breathing problems such as asthma might experience more severe symptoms. Usually symptoms go away when a person leaves the area or goes indoors.”
Health officials recommend that people experiencing symptoms caused by red tide stay away from beach areas or go into an air-conditioned space, the advisory added. “If symptoms do not subside, please contact your health care provider for evaluation,” it noted.
Because of the elevated counts of red tide from Monday’s beach water samples, as well as reports of respiratory irritation, DOH-Sarasota staff were scheduled to post signage on Friday, April 16, at several beaches to advise the public that red tide is present. Those beaches are Longboat Key, Bird Key Park (Ringling Causeway), North Lido Beach, Lido Casino, South Lido, Siesta Beach, Turtle Beach, Nokomis Beach and North Jetty Beach, the advisory said.
In its Dec. 11, 2020 weekly update on red tide, the Florida Fish and Wildlife Conservation Commission (FWC) reported, “A bloom of the red tide organism, Karenia brevis, was observed in Southwest Florida over the past week. Background to low concentrations of K. brevis were detected in 36 samples. Bloom concentrations (> 100,000 cells/liter) were observed in five samples from or offshore of Lee and Collier counties.”
Although FWC added that the next red tide status report would be issued on Dec. 18, 2020, the agency ended up switching to mid-week updates as a result of growing concerns about red tide in Southwest Florida.
A Dec. 16, 2020 report said Karenia brevis was observed in background to high concentrations in 22 water samples taken in Lee County “and very low to high concentrations in and offshore of Collier County (in 7 samples).”
Since that update was issued, FWC has continued with twice-weekly reports.
On April 14, in its latest midweek update, FWC noted that Karenia brevis “was observed at background to medium concentrations in and offshore of Sarasota County (in 31 samples), very low to high concentrations in Charlotte County (in 4 samples), background to very low concentrations in and offshore of Lee County (in 12 samples) and background to medium concentrations in Collier County (in 6 samples). “Samples from or offshore of Pinellas, Hillsborough, and Manatee counties did not contain red tide,” the report added.
Further, FWC noted that a fish kill reported in Sarasota County was suspected to be related to red tide.
A person may report a fish kill by following the directions on an FWC webpage, the update pointed out.
Additionally, the April 14 update said, respiratory irritation was reported over the past week in Sarasota County.
The previous report, dated April 9, said the red tide algae “was observed at background to low concentrations in Sarasota County …”
At 10:18 a.m. on April 14, the Mote Beach Conditions report for Siesta noted “Slight” respiratory irritation, but no dead fish. The water color, it added, was “Moderate.”
The wind was out of the east-southeast.
The 8:38 a.m. report on April 15 for Siesta said the wind was out of the south-southeast, the water was clear and respiratory irritation was slight.
The Mote reports in recent days also have indicated the presence of brown and red macroalgae on the beach — what is referred to as “drift algae.”
American Scientist explains, “Macroalgae come in a great many varieties. Some of the larger ones have complex structures with special tissues that provide support or transport nutrients and the products of photosynthesis; others are made up of cells that are all virtually identical. The smallest seaweeds are only a few millimeters or centimeters in size, while the largest routinely grow to a length of 30 to 50 meters. Seaweed cells also come in different sizes; in many species they can measure one centimeter or more.”
It adds, “Macroalgae are classified into three major groups: brown algae (Phaeophyceae), green algae (Chlorophyta), and red algae (Rhodophyta). As all of the groups contain chlorophyll granules, their characteristic colors are derived from other pigments. Many of the brown algae are referred to simply as kelp.”
Piney Point discharges not a factor, Mote says
Water quality concerns in the region have been elevated over the past couple of weeks as a result of the releases from the former Piney Point fertilizer plant property. The owner of the site, HRK Holdings, had alerted state officials to a leak in a reservoir containing more than 450 million gallons of wastewater.
As the Tampa Bay Times has reported, “State regulators allowed discharges to Tampa Bay through [Port Manatee], fearing pressure from the leak would break apart a phosphogypsum stack around the pond [on the Piney Point site] and cause a devastating flood.”
The article explained, “Phosphogypsum is a radioactive byproduct of the fertilizer industry.”
As of April 12, the Times pointed out, about 215 million gallons of polluted water from Piney Point, “high in nutrients,” such as nitrogen, “have been discharged to date.”
Nitrogen is the primary food source for Karenia brevis, Mote Marine researchers have noted.
On April 14, the Sarasota Herald-Tribune reported that a computer model used by researchers at the University of South Florida was showing the plume of wastewater from Piney Point spreading as far south as the Manatee River, “as it slowly heads out toward the Gulf of Mexico.”
Nonetheless, when the News Leader spoke on April 13 with Stephanie Kettle, public relations manager for Mote Marine, she stressed that red tide has been present south of Sarasota County for months. The environmental changes observed on the Sarasota County shoreline over recent days had nothing to do with Piney Point, she said.
Mote updates its Beach Conditions reports twice daily, Kettle noted, adding that anyone concerned about problems can check the data before heading to the shore.