Mexico’s Sargassum Crisis: Will New Efforts Finally Work?

Mexico — The Mexican government has announced improved coordination to address the recurring sargassum seaweed influx along the Caribbean coast, though skepticism remains about whether this administration will achieve more than its predecessor.

A Persistent Ecological Challenge

In early 2019, Mexico faced an unprecedented sargassum influx, described as an “ecological disaster.” However, then-President Andrés Manuel López Obrador dismissed it as a minor issue, attributing it to previous administrations that had allegedly exaggerated the problem for financial gain. He tasked the Secretariat of the Navy (Semar) and an interinstitutional commission led by the Secretariat of Environment and Natural Resources (Semarnat) with managing the situation.

The issue faded from prominence in 2020 due to reduced seaweed arrivals and the onset of the COVID-19 pandemic. However, large quantities returned in 2021 and 2023, overwhelming local efforts to contain and remove the algae. Despite repeated failures to intercept sargassum at sea or dispose of it properly, López Obrador claimed 50 days before leaving office that his administration had resolved the problem—a statement unsupported by official reports from Semar or Semarnat.

Scientific Concerns and Regional Impact

The declaration surprised tourism stakeholders, the Quintana Roo state government, and scientists. A group of 44 researchers from 21 institutions, including the National Autonomous University of Mexico’s Institute of Marine Sciences and Limnology, the Center for Scientific Research and Higher Education in Ensenada (Cicese), and universities in Yucatán, Quintana Roo, Campeche, and Veracruz, have long studied solutions to mitigate sargassum’s impact.

Their findings, published in La Jornada Ecológica (August 2019 and March 2023), highlight that increased seaweed arrivals stem from ocean currents, climate change, and nutrient runoff from fertilizers entering the Sargasso Sea—now spanning 3.5 million square kilometers. Experts urge converting sargassum into usable products like biofuels, animal feed, fertilizers, or construction materials, but government support for such initiatives has been lacking.

Environmental and Health Risks

Decomposing sargassum releases hydrogen sulfide, posing health risks to humans and endangering coral reefs, wetlands, mangroves, and threatened species like sea turtles. The once-turquoise waters of the Mexican Caribbean have turned murky, while beaches remain buried under tons of algae.

The current administration inherited a record-breaking influx in 2025—over 100,000 tons—making containment nearly impossible along Quintana Roo’s coastline. Officials now claim improved coordination between Semarnat and the state government, along with plans to repurpose the seaweed. However, critics warn against repeating the previous administration’s cycle of optimistic promises without tangible results.