Sun, white sand and turquoise sea. Lido Key Beach in Sarasota would have been the perfect Florida beach postcard if not for dozens of dead fish after weeks of red tide on the west coast of this US state. .
This recurring phenomenon caused by the proliferation of ‘Karenia brevis’ microalgae has come at a bad time this year for the region’s important tourism sector. “Spring Break,” the spring school holidays that flock thousands of Americans. Florida coast.
“We had a lot of cancellations,” says Jeff Napier, an employee at the Lido Beach Resort Hotel. “People get sick. Why would anyone want to spend a lot of money to stay here?” Under these circumstances?
When concentrations of this harmful algae are so high, as happened this month off Florida in the Gulf of Mexico, the toxins it releases can kill marine animals and cause respiratory complications for some people. It also leaves a bad smell.
Dick Bowser experienced it a few days ago. This 80-year-old tourist walks along the coast with his hiking pole in each hand. I’m happy that the currents have kept the red tide away from Sarasota, at least for a while.
“It smelled so bad. You couldn’t be near the beach,” he recalls. “I had a constant cough. I had a sore throat every day and had problems with my eyes and sinuses.”
Napier, 62, has had migraines for five days and never wants to experience them again. “That red tide has to be fixed, but I don’t know what we can do about it,” he says.
Scientists at the Mote Marine Research Institute, located 50 kilometers from Lido Key Beach, have been working to mitigate the effects of red tide since 2020. This phenomenon was already reported by Spanish explorers in the 15th and his 16th centuries after their interactions with the native peoples of the region.
The goal is to “kill the algae, denature their toxins, and prevent them from significantly impacting other species,” explains Michael Crosby, the lab’s president and CEO.
To achieve this, the researchers have a 2,600 m2 center where they cultivate specimens of “Karenia brevis” in giant seawater tanks that mimic the ecosystem of the Gulf of Mexico, where they add substances to neutralize them. can be tested.
So far, Crosby said, 12 methods have been identified that work, and they plan to test them at sea in the next two years.
“We will never be completely free”
A white-bearded scientist tours the research center’s six laboratories with pride as his team works to reduce the environmental impact of red tide and its impact on the region’s quality of life and economy. I’m sure you can. .
But he doesn’t want to give false hope as to the possibility of eradicating the problem.
The main reason is that it is a natural phenomenon, unlike other harmful algae blooms that are often the result of human activity on land and in water, such as agriculture.
Florida’s red tides start about 40 miles off the west coast of the state, approaching the coastline or not following currents.
Crosby explains that the biggest factor in this year’s flowering is the drag effect caused by Hurricane Ian, which hit Florida in late September.
Upon reaching shore, microalgae proliferate upon contact with nutrient-rich waters provided by nature and agriculture.
“We are looking at how much human activity, especially terrestrial nutrition, exacerbates red tide in terms of intensity and duration,” says Crosby.
“But even if we eliminated all humans from Florida, we would still have red tides,” he adds.
On the terrace of Lido Beach Resort, Napier seems to have given up on living with the phenomenon. “You have to be aware that Florida has red tide, and it’s been going on for hundreds of years,” he laments.