Florida has an algae problem, and it’s big. This year, an overgrowth in the waters off the state’s southwestern coast is killing wildlife and making some beaches noxious.
The toxic algal bloom, known as a red tide, is not unusual. They appear off the state’s coast almost every year. But this one, still going strong after roughly nine months, is the longest since 2006, when blooms that originated in 2004 finally abated after 17 months.
The blooms can poison marine animals like sea turtles and manatees, while waves and ocean spray can carry toxins into the air and cause respiratory problems in people.
They can also hit the local tourism industry hard.
“We’re all being really devastated,” said Rachel Wells, 24, who manages an ecotourism business in Englewood, Fla. that runs catamaran tours in the Gulf of Mexico. “Business is just being hurt because we can’t conscientiously suggest for our guests to come out.”
Her company has not done a tour in two weeks, she said, and has temporarily laid off six employees until business picks up again.As for the wildlife, almost 300 sea turtles have been found dead since January in four counties south of Tampa that have been affected by the bloom, far more than the usual number.
Although some of the turtles may have been tangled up in fishing lines, hit by boats or died from diseases unrelated to the algae blooms, Allen Foley, a wildlife biologist at the Florida Fish and Wildlife Conservation Commission, said he believed that a majority of the turtle deaths were attributable to the red tide.
“It’s a very safe bet,” he said.
Beaches have been covered in dead fish, too, causing a foul smell on top of the respiratory problems that have hit some people, Ms. Wells said.
“It is nasty here,” wrote Beth Camisa of Englewood, Fla., in a Facebook group dedicated to sharing information about the red tide. “Haven’t been to the beach in weeks.”
The blooms generally appear in late summer or early fall and tend to die off sometime before the following summer. In a normal year, factors like winds, currents and competition from other types of algae cause them to dissipate. This time, though, the bloom hasn’t gone away.
Toxic freshwater algal blooms, originating inland at Lake Okeechobee, have also caused concern in southern Florida this summer. Spread by controlled water releases from the lake, the blooms prompted Governor Rick Scott of Florida to issue an executive order this month to help battle the algae.
These blue-green algae, which appear in the lake almost every year, are promoted by stagnant water, high temperatures and nutrients from sources like fertilizers, said Christopher J. Gobler, professor of marine science at Stony Brook University.
“That lake is heavily impacted by citrus agriculture,” he said.
Climate change is expected to intensify the freshwater algal blooms, according to Timothy Davis, associate professor of biology at Bowling Green State University in Ohio.
“They really flourish in warm waters,” he said. Also, increased rainfall can bring more nutrients into lakes. “We’re expecting to see larger blooms that last longer and could potentially be more toxic.”
The extent to which climate change is affecting the blooms at sea is unclear. For the red tides off Southwest Florida, researchers “don’t have enough data to really answer the question,” said Richard P. Stumpf, an oceanographer at the National Oceanic and Atmospheric Administration who studies harmful algae. “It’s a hard problem.”