A huge stretch of ocean near Florida has been taken over by Karenia brevis, a microscopic algae that can kill fish and marine mammals, contaminate seafood and turn the water a dark, brown-red color.
The Florida Fish and Wildlife Conservation Commission reported elevated levels of the algae over last week, and said their tipline received multiple reports of thousands of dead fish and marine organisms. According to the FWC, images from the Optical Oceanography Laboratory at the University of South Florida show a bloom 60 miles wide and 90 miles long.
That makes this the biggest bloom in nearly a decade, Hayley Rutger, a spokeswoman with Mote Marine Laboratory and Aquarium, told the Orlando Sentinel.
While the bloom is not yet affecting beaches, boaters have reported respiratory irritation from the algae. The Florida Department of Health says that red tide can also cause skin and eye irritation if you decide to swim in the stuff. Coughing, sneezing and watery eyes can also occur if the toxins are blown onshore, but this bloom remains far enough out that it hasn’t yet bothered beachgoers.
Red tides occur naturally almost every year, but it can be difficult to predict their behavior more than three days in advance.
"The red tide that pops up off the coast of Florida is very unpredictable," Quay Dortch, an algal bloom researcher at the National Oceanic and Atmospheric Administration, told NBC News.
NBC also reported that a 2013 red tide killed 273 endangered manatees. The manatees ate the toxic algae when it got too close to shore and settled on sea grass. Dolphins can also be killed when they eat fish containing high concentrations of the toxins. According to the FWC, the largest dolphin die-off from a red tide occurred between 1987 and 1988, when 740 dolphins were found stranded on the coast.