Red tide conditions shown to be moderating

No bloom conditions cited in Nov. 6 FWC update

These are the red tide status maps reflecting sampling from Oct. 29 through Nov. 6. Image courtesy FWC and the University of South Florida

Red tide conditions in Sarasota County have improved over the past several days, as the Florida Fish and Wildlife Conservation Commission (FWC) made clear in its Nov. 1 and Nov. 6 updates.

“Over the past week,” the Nov. 1 report said, “the red tide organism Karenia brevis was detected in 76 samples collected from Florida’s Gulf Coast.” That figure was down from 85 in the Oct. 30, midweek report.

“Bloom concentrations (>100,000 cells/liter) were present in 18 samples,” FWC added; the Oct. 30 figure was 21. The Nov. 1 report listed the number of such samples and the associated county, as follows: 3 from and offshore of Sarasota County, 2 offshore of Pinellas County, 4 offshore of Charlotte County, 8 offshore of Lee County, and 1 offshore of Collier County.

FWC then noted that, in Southwest Florida over the past seven days, Karenia brevis was observed at background to high concentrations in and offshore of Sarasota County, background to medium concentrations in and offshore of Pinellas County, very low to low concentrations in and offshore of Manatee County, background to high concentrations in and offshore of Charlotte County, very low to medium concentrations in and offshore of Lee County, background to medium concentrations  offshore of Collier County, and background concentrations offshore of Monroe County.

Further, that Nov. 1 report pointed out that fish kills suspected to be related to red tide had been reported to FWC’s Fish Kill Hotline and other partners over the past week for Southwest Florida. It cited the affected counties as Sarasota, Pinellas, Charlotte, and Lee.

Respiratory Irritation suspected to be related to red tide was reported, as well, during the preceding seven days. Those reports came from the same four counties, FWC noted.

This is the Harmful Algal Bloom (HAB) satellite image of the Southwest Florida coast from Oct. 30. Image courtesy of the National Oceanic and Atmospheric Administration’s National Centers for Coastal Ocean Science
This is the HAB color code guide. Image courtesy NOAA NCCOS

By the time the Nov. 6, midweek update was released, the number of Gulf Coast samples in which Karenia brevis had been detected — over the previous seven days — had declined to 51.

“Bloom concentrations (>100,000 cells/liter) were not observed,” that update added. “Satellite imagery” — from the National Oceanic and Atmospheric Administration (NOAA) and the University of South Florida — from Monday, Nov. 4, continued “to show a large offshore patch (>165 miles long) of elevated chlorophyll spanning Pasco to Collier counties, and a few isolated patches further north, off of the Big Bend region,” FWC said. “Confirmatory offshore sampling was not possible over the past week due to weather.”

FWC added, “We suspect that red tide continues to be present offshore.” However, it continued, “[W]e are seeing other algal species dominant in nearshore samples … and it is possible that the chlorophyll signal represents a mixed assemblage, not just red tide. Offshore sampling over the next week will help provide more information,” the update pointed out.

Then FWC noted that in Southwest Florida over the past seven days, Karenia brevis was observed at background to low concentrations in Sarasota, Charlotte and Lee counties, background to very low concentrations in Pinellas County, very low to low concentrations in Manatee County, and background concentrations in Collier County.

Nonetheless, FWC pointed out, fish kills suspected to be related to red tide were reported to FWC’s Fish Kill Hotline and other partners over the past seven days along the coastlines of Sarasota, Pinellas, Charlotte, Lee, and Collier counties and offshore of Collier County.

Further, respiratory irritation also suspected to be related to red tide was reported for the same areas.

Above are the Nov. 7 reports for specific conditions at Lido Beach and at Nokomis Beach, courtesy of Mote Marine’s Beach Conditions Reporting System

For forecasts that use FWC and partner data, please visit the National Oceanic and Atmospheric Administration’s Gulf of Mexico Harmful Algal Blooms Forecast,” FWC says.

The next status report will be issued on Nov. 8. “Please check our daily sampling map, which can be accessed via the online status report on our Red Tide Current Status page,” FWC advises the public.

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