Red tide bloom concentrations in Southwest Florida once again at highest level in Sarasota County

Fewer samples collected show cell counts higher than 100,000 per liter

Slightly fewer samples of water taken in and offshore of Sarasota County over the past week showed bloom concentrations of the red tide algae, Karenia brevis, the Florida Fish and Wildlife Conservation Commission (FWC) has reported.

The total declined from 40, as noted in the Nov. 9 report, to 32 in the Nov. 16 update.

To be considered a bloom concentration, the algae cells must add up to more than 100,000 per liter.

Altogether, FWC said in its Nov. 16 report, Karenia brevis was found in 74 samples collected in Southwest Florida since Nov. 9, with bloom concentrations appearing in 46 of them. Along with those collected in Sarasota County, 10 came from Lee County waters; two from Charlotte County; and one apiece from Manatee and Collier counties.

Further, FWC noted that reports of fish kills that appeared to be related to red tide came in over the past week from Sarasota, Manatee, Charlotte and Lee counties.

Additionally, respiratory irritation linked to red tide was reported over the past week in Sarasota, Manatee, Charlotte, Lee and Collier counties.

The Nov. 16 update from FWC was its first official midweek report since the last major red tide event ended in early 2019. The agency said it would issue its next update on Nov. 18.

On Nov. 10, the Florida Department of Health in Sarasota County expanded an earlier Red Tide Advisory to cover all 16 beaches on the county’s shoreline. That was based on water samples collected on Nov. 7, the department said.

No new update was issued this week as of the deadline for publication of this issue of The Sarasota News Leader.

A News Leader spot check of conditions at various county beaches on Nov. 17 — with details provided by Mote Marine Laboratory’s website — found that the water color at Siesta Public Beach as of just after 10 a.m. that day was classified as “Moderate” with “Some” red seaweed on the shoreline. Respiratory irritation was put at “Slight,” but no dead fish were reported.

Two days earlier — on Nov. 15 — the respiratory irritation was characterized as “Moderate”; the water color, likewise. “Some” brown seaweed was reported on the shoreline.

Just after 1 p.m. on Nov. 17 at Caspersen Beach, south of Venice, the water color was listed as “Moderate,” while no respiratory irritation, no dead fish and no seaweed were reported.

On Lido Beach on Nov. 17, the water color was “Moderate,” while “Some” brown seaweed was on the shoreline. Respiratory irritation was characterized as “Slight.”

Further, that report, provided just before 2:30 p.m., noted that “Some” dead fish were on the beach and in the Gulf of Mexico.

On Nov. 15, no dead fish were reported, but the respiratory irritation again was classified as “Slight,” and “Some” brown seaweed was found on the beach and in the water.

Finally, just before 4 p.m. on Nov. 17, the report for Longboat Key listed the water color as “Moderate,” with “Some” debris on the beach and “Slight” respiratory irritation. However, no dead fish were reported.

On Nov. 15, Longboat’s beach report said no respiratory irritation, no beach debris and no dead fish were noted.