Great Atlantic Sargassum Belt self-sustaining

Since 2011, massive blooms of pelagic sargassum seaweed have repeatedly inundated beaches across the Caribbean, Gulf of Mexico, and tropical Atlantic, forming the Great Atlantic Sargassum Belt. In 2025, the belt surpassed an estimated 37,500 million tons, with forecasts suggesting summer 2026 could break records. Researchers from Georgia Tech, including Xing Zhou, Annalisa Bracco, and Joseph Montoya, propose that the blooms have entered a self-sustaining cycle: the floating mats, which they call the 'sargassumsphere,' host a mobile ecosystem that recycles and concentrates nutrients, feeding subsequent blooms. Their mathematical model, validated against data from the United States — United States Virgin Islands, reproduced historical blooms and predicted 2023-2024 blooms, indicating the belt is likely here to stay. The seaweed clogs harbors, disrupts fishing and boating, harms marine life, and releases hydrogen sulfide, ammonia, and methane as it decomposes, raising public health and environmental concerns. In response, affected regions are exploring uses for sargassum as biofuel feedstock, fertilizer, and construction material. For example, Barbados is developing biofuel from sargassum and rum wastewater, and Mexico and Brazil are investigating sargassum-based building products, including panels from the National Autonomous University of Mexico and bricks by entrepreneur Omar Vazquez Sanchez.