Red tide is a "naturally occurring algae that has been documented along Florida's Gulf Coast since the 1840s and occurs almost every year".
At least 400 sea turtles have died, Newsweek is reporting.
FWC marine turtle biologist Robbin Trindell says the increased number is due, in part, to the red tide affecting numerous beaches where the turtles nest during the summer time.
With red tide, the water might be a little discolored with a hint of red or brown but it's not always visible. Tissue taken from the whale shark's organs and muscles tested positive for brevetoxin, a neurotoxin created by the algae.
The city is issuing a daily "fish kill clean-up" report because of the "unprecedented volume of dead sea life now washing up".
Officials say almost 400 sea turtles have died because of the toxic bloom. The FWC reports that this recent bloom has been monitored since November.
The deputy contacted Florida Fish and Wildlife Conservation Commission and a marine biologist determined the manatee was paralyzed due to the red tide after the deputy described its symptoms. Those who are looking for spots free of red tide can visit https://visitbeaches.org and myfwc.com/redtidestatus to see which beaches have been affected.
But the bloom is not only unsafe to marine animals. The algae can also cause respiratory problems in humans.
The toxin in red tide is dispersed into the air when bubbles in sea foam pop, Fanara said.
Usually, cold spells break up or kill off some of the algae, but not this time.
The excess amount of algae absorbs much of the oxygen in the water, killing off marine life beneath the surface.