Mexico clears 100,000 tons of sargassum as seaweed crisis hits tourism

A massive amount of sargassum seaweed – 100,000 metric tons – has been cleared from Mexican beaches in 2026, according to local authorities. The seaweed crisis, which has hit the country's tourism industry, has been ongoing since 2011. Beaches in the Riviera Maya and Tulum are affected by the floating seaweed mats, which emit a foul smell when decomposing.

The Great Atlantic Sargassum Belt (GASB) stretches from West Africa to the Gulf of Mexico, covering about 5,000 miles. It has reached record levels in 2026, with satellite measurements showing 37.5 million metric tons of the seaweed across the Atlantic. USF researchers recorded 33.6 million metric tons in June. The quantity is expected to double roughly every five years.

Sargassum is a brown seaweed that forms floating mats in the North Atlantic. It provides habitat for marine animals and absorbs carbon dioxide. However, when it reaches coastlines in large quantities, it releases hydrogen sulfide, a toxic gas, and can damage coral reefs. Record amounts have reached the Caribbean coastlines. In the western Caribbean, around 1 million metric tons were already present in January, nearly 10 times the usual amount.

Mexico has been fighting the seaweed invasion with boats, barriers, and manual beach cleaning teams. The Mexican Navy has deployed 27 specialized ships since 2019 to contain the seaweed. Despite the efforts, sargassum has still reached many beaches in the Mexican Caribbean, causing a decline in tourism. Hotel occupancy rates have dropped to between 55% and 70%, compared to the 90% peak in previous years.