Sargassum Smothers Mexican Caribbean: Record 2025 Levels

Mexico City — The Mexican Caribbean is facing one of its worst ecological crises in recent years after the National Autonomous University of Mexico (UNAM) reported 37.5 million tons of sargassum floating in the region in May—the highest volume ever recorded.

The brown seaweed, belonging to the Sargassum genus and typically originating in the Sargasso Sea of the North Atlantic, has reached unprecedented levels along Mexico’s coastline, severely impacting tourism, fishing, and public health in Caribbean states.

Unprecedented Threat to Coastal Regions

Lorenzo Álvarez, a researcher at UNAM’s Institute of Marine Sciences and Limnology, warned that sargassum accumulation is expected to increase from June through August, with even greater impacts in areas like Tulum, Mahahual, Xcalak, Playa del Carmen, and Cozumel.

While living sargassum serves as a habitat for marine species, its decomposition on shorelines releases toxic gases that irritate eyes and respiratory systems, raising health concerns for residents and tourists alike.

Government Response and Operational Measures

Mexico’s Navy (Semar) reported collecting 4,236 tons of sargassum so far in 2025 across Quintana Roo’s seven major ports. Authorities have launched Operation Sargasso 2025, deploying 13 maritime units to remove the seaweed in open waters before it reaches the coast.

Climate Change and Pollution Blamed

Briggita Ine Van Tussenbroek, founder of UNAM’s Seagrass Laboratory, stated that the surge is directly linked to climate change, nutrient pollution, and shifting ocean currents. The alarming situation has prompted urgent calls from local officials, academics, and tourism businesses for coordinated, sustainable solutions to what is now considered an environmental emergency in the Mexican Caribbean.