The smelly sargassum arrived at the tourist beaches of Florida to stay, according to the University of South Florida (USF), which this year foresees an invasion of this brown seaweed even worse than that of 2018 as long as the nutrient spill continues to the Atlantic from the coast African and South American.

After recently revealing the discovery of the largest flowering of these macroalgae in the world, with a length of up to 8,850 kilometers, thanks to the analysis of NASA satellite images, the university detailed in a study the impact that this "invasion" will have on the peninsula of Florida.

Although currently "it is not a real threat to the United States, it does represent a problem for some beaches on the east coast of Florida," Chuanmin Hu, one of the authors of the report, told Efe.

The oceanographer said that the other affected state in the country is Texas, where "its appearance has been routine, even before 2011", when the "massive blooms" of this seaweed began in the Atlantic.

In Florida, where tourism plays an important role in the economy of the region, its appearance was also noticed with great force as of 2011 and has been increasing, except in 2013, until reaching a record in 2018, according to the study. However, the most worrying thing is that the phenomenon did not stop when the temperatures dropped.

"During the winter months, the majority of sargassum disappears in the satellite images, but this year is unusual," explained the professor of the School of Marine Sciences at USF who analyzed more than ten years of these snapshots.

He noted that he does not believe there are exact figures on the economic damage caused by sargassum on tourist beaches in the Caribbean and Mexico, but considers that they must be "very serious", judging by the declaration of "national emergency" in some countries of the region.

Sargassum Seaweed Blooms in Florida. USF College of Marine Science - University of South Florida
Sargassum Seaweed Blooms in Florida. USF College of Marine Science - University of South Florida

The impact in Florida is not clear either. For now, tourists and residents complain about the smell where this seaweed accumulates and the yellowish appearance of the water in some tourist beaches, usually crystalline. That's the slice of Florida's so-called Great Sargasso Atlantic Belt (GASB) detected by the USF last week that stretches from West Africa to the Caribbean Sea and the Gulf of Mexico.

The study, led by Professor Mengqiu Wang, details that although Christopher Columbus reported floating mats of these algae in the middle of the Atlantic since the fifteenth century, the alarming thing from 2011 is that they have increased in "extension and density".

"Such recurrent blooms can become the new normal," Wang said.

Hu, for his part, explained that the flowering in the Caribbean during the first months of this year was even worse than that of 2018, which indicates that it will persist in the coming months.

"They are probably here to stay," lamented Hu.

He explained that the sargassum smells when it concentrates large amounts and rot, which has been detected in some beaches of the South Beach tourist area. "Thick algae release hydrogen sulfide gas and smell rotten eggs, which can be problematic for people with respiratory problems," the study says. However, Hu said that the smell is not the biggest problem since there are other adverse economic consequences and for marine wildlife.

In the open sea, sargassum serves as a habitat and refuge for several marine animals, Wang explained. "I often sawfish and dolphins around these floating mats." But at the same time, it hinders the ability of some marine species to move and breathe. In addition, algae can also smother corals and seagrasses if large numbers die and sink to the bottom of the ocean.

The explosion of this seaweed, according to the report, indicates that there have been changes in the chemistry, biology, and/or physics of the ocean related to the consumption of fertilizers in Brazil, the rates of deforestation in the Amazon, and the discharge of the Amazon River.

"In summary, more nutrients, such as nitrogen, mean more seaweed."

Added to this are natural nutrient discharges from the West African coast. "All this is related to climate change because it affects rainfall, ocean circulation, and even human activities, but what we have shown is that these blooms do not occur due to the increase in water temperature," Hu said.

The USF report details that in 2018 the seaweed belt, which reached 20 million tons, more than 200 fully loaded aircraft carriers, wreaked havoc on the coasts bordering the tropical Atlantic, the Caribbean Sea, the Gulf of Mexico, and the east coast. from Florida.