Florida’s west coast was painted in a deeper shade of red last week as red tide bloomed in greater concentrations since the previous week, the Florida Fish and Wildlife Conservation Commission showed in its Wednesday update.
The dinoflagellate Karenia brevis, also known as red tide, was found in high concentrations in Sarasota, Charlotte, Lee, and Collier counties, the update showed.
A “high concentration” of red tide means that FWC scientist found over 1 million red tide cells per water sample liter, the FWC said.
This is a significant difference from the previous week which only found high concentrations of red tide in Collier and Lee counties, an Oct. 30 report shows.
Sarasota, Charlotte and Pinellas counties tested positive on Oct. 30 but contained medium concentrations.
Red tide is a naturally occurring phenomenon, however massive blooms of the algae are problematic and can lead to respiratory irritation for humans, water discoloration and marine life deaths because of the lack of oxygen in the water.
Respiratory irritation was reported this week in Sarasota, Charlotte, Lee and Collier counties, FWC said.
Over 30 fish kills associated directly with red tide have been reported since the start of September, with the majority found around Naples, Sanibel and Marco Island waters.
Scientists believe ocean currents should spread the algae over the next four days into southern waters toward Monroe County, the FWC forecast shows.
While naturally occurring, some people debate whether the prolific growth of red tide blooms are human related as the algae can feed directly on fertilizer runoff, which contains vast amounts of phosphorous and nitrogen - two key ingredients for red tide, according to the Mote Marine Laboratory and Aquarium.
Between late 2017 and 2018, Florida was ravaged by one of the worst red tide blooms in its history covering over 150 miles of west coast beaches. Last year’s bloom was so prevalent that the algae grew in parts of Florida where red tide is rarely observed such as the panhandle and the east coast.
The damage was estimated at $130 million, not including the hit Florida beach tourism took with people choosing to visit other places.
Red tide was not detected on either Florida’s east or north coasts.