A huge mass of brown algae drifts towards the US coast and beaches in the Gulf of Mexico. In total, around 6.1 million tons of algae moved from the Central Atlantic towards the Caribbean, reported marine scientists from the University of South Florida. This is the second largest amount of algae since records began in 2011. The first offshoots of the algae cloud had already washed up on beaches in Mexico's Yucatán Peninsula, it said. According to media reports, beaches on the island of Key West, at the southern tip of the USA, are already affected.
The algae affect the important tourism industry in the region. When the algae decompose after landing, they release the rotten-smelling gas hydrogen sulfide, the Florida Health Department wrote on its website. The gas is not dangerous, but can irritate eyes and respiratory tract. In addition, microorganisms living in the algae could, for example, lead to skin rashes. Researchers also warn against consuming the algae or using them as fertilizer. They could contain large amounts of heavy metals such as arsenic or cadmium, it said.
The algae themselves are not new. Christopher Columbus described them in the 15th century, scientists wrote in a 2019 study. Since 2011, however, their spread has increased massively. The algae carpet stretches from West Africa to the Gulf of Mexico, the scientists wrote. The exact reason for this is still unclear. The excessive growth could be related to the input of nitrogen and phosphorus from large rivers such as the Amazon, the Congo or the Mississippi into the oceans, Brian Lapointe of Florida Atlantic University told the New York Times.