The Ocean 'Was the Color of Chocolate.' Mexico Declares War on Seaweed.

Mexico is mounting a naval campaign against sargassum, a naturally occurring seaweed whose enormous blooms now blanket Caribbean shores. Satellite tracking, drones and converted ships with conveyor belts let crews collect the algae offshore before it reaches beaches. The effort expanded after a record season: nearly 23 million tons entered the western Caribbean this year, while the Navy collected about 25,000 tons at sea through September - more than twice last year’s total, but less than a third of what was later removed from shore. The government has committed $115 million to new vessels and smaller boats, hoping to shift most collection offshore.

The crisis is driven by currents and winds carrying sargassum beyond its traditional habitat, where warmer water, sunlight and nutrient runoff help it grow rapidly. Its spread is damaging tourism along Mexico’s Mayan Riviera: brown, foul-smelling beaches have deterred visitors, reduced excursions and sales, and strained workers and businesses. Decomposing seaweed can also release gases harmful to people. Mexico’s approach may offer a model for other affected countries, but it is uncertain whether collection can keep pace with continued growth. A parallel industry aims to turn the costly cleanup into a circular economy, making products such as fertilizer, construction materials and cosmetics from harvested seaweed. New processing facilities and international investment are emerging, though commercial opportunity does not remove the challenge of preventing vast blooms from reaching shore.