Startup Turns 20,000 Tons of Beach Seaweed Into Products

Every morning in Puerto Morelos, Mexico, crews haul away truckloads of stinky brown seaweed from beaches that were buried overnight. But one company sees treasure in what others treat as trash.

Sargassum seaweed has exploded across Caribbean beaches in recent years, reaching a record 38 million tons in July 2025. The invasive algae blankets Mexican shores in mats several feet deep, smelling of sulfur as it decays in the sun.

The economic damage is staggering. Hotels in Quintana Roo spent $150 million last year just clearing beaches, while total losses from major blooms top $275 million. Tourism locations hit by sargassum see a 10% GDP drop during blooms, threatening a region that generates over $16 billion annually from visitors.

For years, most collected sargassum ended up in landfills. Now that's changing as companies race to turn the problem into profit.

Carbonwave, a U.S. startup operating along Mexico's Riviera Maya, collected roughly 20,000 metric tons of sargassum last year. The company employs about 75 full-time workers and runs what may be the world's largest sargassum collection operation.

The company uses mechanical equipment, manual labor and floating barriers to gather seaweed from beaches between Playa del Carmen and Tulum. On average processing days, the facility handles around 20 tons, with record days hitting 60 tons or more from collection zones alone.

The company transforms the collected algae into usable products instead of sending it to dumps. On most days, virtually everything collected gets processed and sold rather than wasted.

Scientists are still puzzling out why sargassum keeps growing. A 2025 Nature Geoscience study pointed to deep ocean phosphorus upwelling as the main driver, with bacteria on the seaweed fixing nitrogen that accelerates growth. Climate changes may be slowing ocean currents that normally pull nutrients deep, potentially supercharging blooms through mid-century.

The season itself is expanding dramatically. Sargassum traditionally peaked from May to August, but this year collections started in January, pushing into prime tourist months.

The Ripple Effect

Carbonwave's 20,000 tons represents between an eighth and a half of what hits Quintana Roo's beaches annually, depending on estimates. While the company can't yet match the scale of the problem, it's proving the model works.

On record days when sargassum arrives faster than crews can process it, some still goes to landfills. But every ton transformed into products is one less contributing to the environmental burden.

Other companies are joining the race to turn seaweed into solutions, each one adding capacity to handle what's becoming one of the Caribbean's most visible climate challenges.

What started as an environmental crisis is slowly becoming an innovation opportunity, one truckload at a time.