Sargassum Blooms Threaten Atlantic Coast Beaches and Tourism

Massive blooms of the brown seaweed Sargassum have formed a continuous stretch across the Atlantic, dubbed the Great Atlantic Sargassum Belt. From April through September the floating mats wash ashore in large quantities, coating beaches in Mexico, the United States (Florida), the Caribbean and parts of West Africa.

The influx creates ecological and economic challenges for coastal communities that rely on tourism. Officials cite warming oceans, altered currents, nutrient runoff from agriculture and wastewater, and river discharge as drivers of the rapid expansion. While researchers are exploring ways to turn the seaweed into biomass fuel or fertilizer, viable commercial uses are not yet established.

Local authorities are scrambling to manage the odor and debris, which degrade visitor experiences and threaten revenue for hotels, restaurants and other tourism‑related businesses.