Huge blankets of seaweed are smothering coastlines from the Caribbean to Mexico

Vast quantities of sargassum seaweed are smothering beaches and coastlines from the Caribbean to the Gulf of Mexico, creating an environmental crisis that is killing marine life and spooking tourists in regions heavily reliant on the industry. Scientists have recorded a staggering 27 million metric tons of sargassum in the Atlantic, Caribbean, and Gulf of Mexico as of July. This year marks a significant shift, as the algae is now reproducing in large quantities within the region itself, rather than solely being carried by currents from Western Africa. This phenomenon, known as the Great Atlantic Sargassum Belt, has been growing since 2011, with experts pointing to factors like agricultural runoff, warming waters, and altered wind and current patterns. Brian Barnes, a marine scientist at the University of South Florida, described the situation as "not normal," noting that the massive bloom in 2025 was so large it never fully dissipated, allowing a new local bloom to begin. Sargassum levels in the Caribbean reached record highs in June, and the Gulf of Mexico saw 5 million metric tons in the same month, nearly double the previous year's record. The environmental threat is also an economic one. Mexico announced plans to invest $115 million to address the blooming algae, which can deposit up to 9,000 tons on its Caribbean coastline on the worst days. However, current resources allow the country to collect only about 1,200 tons daily. In Playa del Carmen, a popular tourist town, waiters like Alan Vázquez are experiencing the devastating impact firsthand. Vázquez closed his restaurant early one evening due to a lack of customers, lamenting the transformation of the once-vibrant turquoise waters into a black, decomposing mess. He fears for his livelihood, as four colleagues have already lost their jobs.

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None of this is normal. Every year is a little bit of a new story.