Low levels of red tide detected in Gulf, state says. Respiratory irritation possible 

The organism that causes red tide, Karenia brevis, was detected at low levels in waters off of Sarasota County on Monday, according to the Florida Fish and Wildlife Conservation Commission.

The toxic algae remained at undetectable levels in the one sample taken offshore of Manatee County.

K. brevis is naturally present in Gulf Coast waters, but at elevated concentrations it can be harmful to wildlife and humans.

Samples collected on Monday showed low levels of the algae (more than 10,000 to 100,000 cells of K. brevis per liter) in seven places off of Sarasota County’s coast, from Blind Pass Beach north to Venice Beach. At low concentrations, the algae is likely to cause respiratory irritation, and fish kills are possible, according to FWC. Shellfish harvesting may also be suspended.

Further northward, very low concentrations (more than 1,000 to 10,000 cells per liter) were observed at North Jetty Beach and Nokomis Beach. Very low concentrations of K. brevis can also cause respiratory irritation.

Monday’s samples were the most significant levels of the algae observed near Southwest Florida since last December, when the area last experienced a red tide bloom.

K. brevis reaches bloom concentration at more than 100,000 cells per liter. Once carried inshore, blooms of K. brevis can be worsened by nutrient pollution from humans or natural sources, according to FWC.

The agency will issue its next red tide status report on Friday.

This story was originally published December 2, 2020 at 5:00 AM.