On the beaches of Quintana Roo, the tide brings more than tourists. In 2025, record waves of sargassum threaten to choke the coastline’s turquoise brand—but engineers and scientists here are betting it can be turned into energy, products, and profit.
A Forecast That Smells of Trouble
For over a decade, brown rafts of sargassum have floated ashore from Cancún to Tulum, transforming clear water into murky shallows and driving visitors away. This year’s forecast is alarming. The University of South Florida’s Optical Oceanography Lab predicts up to 400,000 tons could land on Mexico’s shores, with daily arrivals in some parts of Quintana Roo reaching 70 tons in May—double the average from last year.
The floating mass at sea is even more staggering: after peaking at 22 million metric tons in 2018, monitoring this spring showed 37.5 million tons in May and a projected 50 million by June, according to Esteban Amaro of the Quintana Roo Sargassum Monitoring Network, speaking to Wired.
Once on land, the seaweed quickly becomes toxic. Decomposing sargassum releases hydrogen sulfide, methane, and carbon dioxide, along with leaching heavy metals into the sand and nearshore waters. For tourism-driven towns, that means a health hazard, a stench that clears hotel zones, and a cleanup bill that runs into the millions during high season.
Fueling a Fix with Biogas
To some, the answer is obvious: stop treating sargassum as waste and start treating it as biomass. Miguel Ángel Aké Madera, founder of Nopalimex and a veteran of cactus-to-energy projects, told Wired that every ton of processed seaweed can yield a cubic meter of biogas—roughly the same energy as a liter of gasoline.
He’s done the math. Processing 500 tons a day could produce 20,000 cubic meters of biogas, matching the daily fuel sales of a standard Mexican gas station. And he says that’s just a start: “At 2,500 or 3,000 tons a day, you’d see a real difference within a year.”
Amaro agrees. With sargassum’s tendency to release heavy metals and greenhouse gases as it decays, he warns against turning it into consumer products that could pose health risks. “Sargassum’s vocation is to produce energy,” he said. In his view, biogas and biofuels offer the safest, most scalable way to turn a public nuisance into a renewable asset.
Panels, Credits, and a Circular Economy
Not all roads lead to gas. At UNAM’s Center for Applied Physics and Advanced Technology, researchers have developed Sargapanel, a building material made from 60 to 70 kilos of wet seaweed per panel. According to project lead Miriam Estévez González, the panels are stronger, more flexible, and naturally fire-resistant compared to conventional versions—and they can be recycled at the end of their life.
The benefits aren’t only structural. “Every five tons of wet sargassum equals one carbon credit, valued between 10 and 30 dollars,” Estévez González told Wired. By her estimate, processing 4,000 tons of dried sargassum could earn $80,000 to $240,000 a year in credits while removing the equivalent of 8,000 tons of CO₂ from the atmosphere—like taking 1,000 cars off the road.
Quintana Roo’s government is leaning in. In February, Governor Mara Lezama announced the creation of the Integrated Sargassum Sanitation and Circular Economy Center, aimed at producing biogas, organic fertilizers, and carbon credits. By preventing open-air decay, the center seeks to monetize avoided emissions and maintain clear local waters. In off-season months, when the tide thins, biogas plants could co-digest wastewater sludge to keep output steady.
EFE
Policy Shifts and the Push to Scale
Until recently, sargassum’s legal status was murky, tangled between the navy, environmental agencies, and state authorities. That changed in June, when Mexico’s fisheries research institute proposed classifying it as a fishery product—opening the way for regulated harvesting and sale.
Aké Madera believes that clarity could unlock investment. He’s already proved the concept at his Michoacán plant, hauling in 50 tons from Quintana Roo to test alongside tequila vinasse and cactus waste. “It’s an ideal biomass for biogas,” he said.
Elsewhere in the Caribbean—Dominican Republic, Jamaica, Guadeloupe, Martinique, Dominica—small biodigesters are being tested, but eyes are on Mexico to prove it can be done at scale. Interest is coming from Spain, the Netherlands, Germany, the United States, and France. Two sites near Cancún are under consideration while project plans are finalized.
The ocean’s mood will always be a variable. Could currents change, and the tide go slack? Estévez González says climate trends make that unlikely; warming seas are making sargassum blooms a fixture, not a fluke. And if supply dips, Aké Madera notes, plants could switch to other feedstocks—agave waste, avocado pits, livestock manure—until the next wave rolls in.
For Quintana Roo, the stakes are steep. The Inter-American Development Bank estimates sargassum affects more than 11 percent of the state’s GDP. Hotels spend over $130 million a year on cleanup. The choice isn’t whether the tide will come—it’s whether the system onshore can meet it with shovels or with something more lasting.
Also Read: Supercorals of the Galápagos Fight Back—And Could Save a Reef, a Coastline, and a Way of Life
If the new approach works, the brown tide could become a blue-water insurance policy: fueling buses, building walls, earning carbon credits, and keeping tourists in the water instead of away from it. That would turn a yearly crisis into a resource cycle—and prove that even the most unwelcome arrival can be part of the economy it once threatened.
