With red tide, the water might be a little discolored with a hint of red or brown but it's not always visible.
Mote Marine Laboratory's phytoplankton ecology team, along with the Florida Wildlife Research Institute and Harmful Algal Bloom researchers, conducted a red tide survey along the Florida Gulf coast on Wednesday. The state's governor has declared a state of emergency.
Dozens of sea turtles are also turning up dead.
The Florida Fish and Wildlife Conservation Commission is now examining samples of the algae from different locations along the west coast. Tissue taken from the whale shark's organs and muscles tested positive for brevetoxin, a neurotoxin created by the algae.More news: Robert Redford Retiring from Acting After The Old Man & the Gun
Social media has been inundated with images of dead animals that failed to escape the toxic bloom washing up on the Gulf of Mexico beaches across Florida.
According to the Florida Fish and Wildlife Conservation Commission, the Red Tide along the west coast is the Karenia brevis, a strain of algae that is nearly exclusive to Florida waters.
Scott directed the Florida Fish and Wildlife Conservation Commission and the Florida Department of Environmental Protection to "mobilize all available resources" to address impacts in Southwest Florida.
According to U.S. network CNN, this year's effect of the red tide on marine life has been unprecedented.More news: NASCAR CEO arrested for oxycodone possession, DWI
FWC continues to receive reports of fish kills in Southwest Florida.
But the bloom is not only unsafe to marine animals. They can also cause respiratory irritarion in humans.
Usually, cold spells break up or kill off some of the algae, but not this time.
Toxic freshwater algae blooms started inland at Lake Okeechobee.More news: China hits back at USA with $60bn tariff threat
Siesta Key is known for its blue water and lively marine life.