Scores of dolphins have died along Florida's southwest coast due to the red tide bloom in the past year, federal researchers said.
Figures released by the National Oceanic and Atmospheric Administration showed 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 the southwest Florida Gulf Coast since November 2017.
While red tide has diminished since February and the rate of dolphin deaths off Florida's southwest coast has slowed down, researchers in recent months have seen deaths from the secondary effects of red tide.
Those include dolphins consuming fishing gear because the red tide fish kill-off reduced the supply of the dolphin's usual diet of mullet and trout, forcing them to search for food in atypical places, Blair Mase, NOAA's stranding response program coordinator, said Friday.
Researchers in recent months also have found unusual food in the dolphins' stomachs, such as crabs and eels.
"We're also seeing underweight animals," Mase said.
Red tides happen naturally and have appeared sporadically off the state's coast for ages, but many believe humans have made the problem worse. This past year's bloom caused respiratory irritations in people near southwest Florida beaches.
At the peak of the red tide crisis last November, more than 50 dolphins were stranded after ingesting the toxic algae or eating contaminated fish, according to NOAA's figures.
However, the past year's dolphin strandings aren't the worst ever. Between 2005 and 2006, 190 dolphins were stranded in a mass die-off from red tide.
Earlier this month, Florida Gov. Ron DeSantis signed a bill directing the state to work with a private marine institute to study and combat the red tide blooms that have hurt the state's fishing and tourism industries.
This tally of dolphin deaths off southwest Florida is separate from another count in the northern Gulf. NOAA reported this month that 279 dolphins were stranded since February from Louisiana to the Florida Panhandle. That was triple the usual number and almost all of the dolphins died.