Can sargassum be turned into ‘Caribbean gold’?

Juan Amauris Hernández, a diver for the sargassum-barrier maker AlgeaNova, setting anchors for a barrier in the coastal waters of Punta Cana, Dominican Republic. (Photo by Lautaro Isern)

Every year, vast quantities of sargassum seaweed wash up on the shores of the Caribbean Sea and Gulf of Mexico, threatening coastal communities’ economies and ecosystems. Comprising two free-floating species (Sargassum natans and Sargassum fluitans), the macroalgae is by no means new to the region. Until a decade and a half ago, its seasonal proliferations were limited for the most part to the calm waters of the Sargasso Sea, which lies between Bermuda and the Azores at the center of the great North Atlantic Subtropical Gyre. Back then, manageable quantities of the seaweed would drift each year into Caribbean and Gulf waters. Since 2011, however, annual sargassum blooms have covered a far larger area of the central Atlantic Ocean, their volumes estimated in some years to total over 20 million tons. What scientists call the Great Atlantic Sargassum Belt sometimes stretches from the Gulf of Mexico to West Africa... Read more →