Toxic Red Tide On Florida's Southwest Coast Killing Hundreds Of Turtles And Fish

Dead fish line the shoreline along the Sanibel causeway after dying in a red tide on August 1, 2018 in Sanibel, Florida. Red tide season usually lasts from October to around February, but the current red tide has stayed along the coast for around 10 months, killing massive amounts of fish as well as sea turtles, manatees and a whale shark swimming in the area. The number of dead or ailing sea turtles washing up on Florida’s southwestern coast has soared due to a prolonged algae bloom, raising concerns about the long-term impact on endangered turtle species. Since the start of the year, 287 turtles—dead, sick or injured—have been stranded in the counties of Sarasota, Charlotte, Lee and Collier, said Allen Foley, a wildlife biologist at the Florida Fish and Wildlife Conservation Commission. That is double the five-year average for the same period and the highest toll since 2005 and 2006, when a similar algae bloom erupted. The phenomenon is coinciding with sea turtles’ breeding season, which runs from April to October. Red tides occur naturally in the Gulf of Mexico, and their duration depends on a variety of factors, including sunlight and wind currents. But if they move toward shore, they can be prolonged and intensified by runoff of nutrients like farm fertilizer and treated sewage released into waterways, said Richard Bartleson, research scientist at the Sanibel-Captiva Conservation Foundation, a marine laboratory. Last year’s Hurricane Irma, which swept across Florida, may have exacerbated the current red tide by sending a surge of nutrients into the Gulf of Mexico, he said. Normally, red-tide season ends around April, just as sea turtles’ nesting season starts up. But the current red tide began in October 2017 and shows little sign of subsiding. (Footage by Joe Raedle/Getty Images)