The red tide bloom has killed scores of dolphins along Florida's southwest coast in the past year.
The National Oceanic and Atmospheric Administration says 174 dolphins were stranded in a mass die-off between last July and last week.
Fish, sea turtles and manatees also have died from the red tide bloom, which has plagued Florida's Gulf Coast since November 2017.
According to HuffPost, red tides happen naturally and have appeared sporadically off the state’s coast for ages.