"TULUM, Mexico - A record wave of brown, smelly seaweed is washing up on beaches along Mexico's Caribbean coast, forcing closures in top tourist destinations and inflicting mounting economic damage on hotels, restaurants and shops.
The unprecedented mass of sargassum – a brown seaweed that drifts across the Atlantic in vast mats and is pushed by ocean currents toward Caribbean shorelines in the springtime – has prompted the federal government to prepare an emergency plan to combat the issue.
In the eastern state of Quintana Roo, a tourist hot spot home to once-crystalline beaches including Cancun and Playa del Carmen, environmental officials project 119,000 tons of sargassum to wash up on the shore by year's end, surpassing last year's record of 96,000 tons.
"Warmer temperatures are going to give you more sargassum,” said Brian Barnes, a research assistant professor at the College of Marine Science at the University of South Florida who studies the phenomenon, adding that a combination of nutrients and long days of sunlight also plays a role."
Iñigo Alexander and Paola Chiomante report for Reuters July 28, 2026.
