The 2024 sargassum season in Mexico brought significantly less seaweed than predicted. Could this be a sign that 2025 might also be “good” for tourism?
Data collected over the last four weeks confirms that the unwelcome sargassum season in the Mexican Caribbean has officially ended, leaving considerable losses, particularly in the tourism and fishing industries, though the overall impact was less severe than in previous years.
Although this year saw a relatively mild season, previous years have left massive financial impacts, with clean-up expenses exceeding $120 million annually in Quintana Roo alone.
This week, the government determined that the state received 44,000 metric tons of algae—lower than forecast—according to Óscar Rébora, Secretary of Ecology and Environment (SEMA).
Does this suggest that the 2025 sargassum season will be equally good for tourists and hoteliers? Unfortunately, that’s impossible to tell.
The latest satellite images of the Optical Oceanography Laboratory at the University of South Florida (from October 14 – October 20) are already showing massive sargassum seaweed formation on the Atlantic Ocean but it’s too early to predict where it’s going to float in 2025.
Esteban Amaro Mauricio, hydrobiologist and Director of the Sargassum Monitoring Network, has repeatedly emphasized that nothing is certain: “Nature follows its own patterns, making it very difficult to predict its behavior.”
Therefore, factors such as changing sea currents, the number of hurricanes and tornadoes expected in the Atlantic Ocean in 2025, water temperature and other human-driving factors will play a key role in the amount of seaweed arriving in the region next year.
Due to this uncertainty, the local government is already preparing for the next season, treating this environmental phenomenon as a state priority because of its economic and social implications, Rébora stated.
In addition, 2025 will be a crucial year for developing businesses that can turn seaweed into profitable products.
For the time being, the most pressing concern regarding sargassum is the detection of high levels of heavy metals like arsenic, as well as microplastics, in Mexican waters at the beginning of October.
As soon as sargassum begins decomposing on beaches, it releases toxic gases like ammonia, hydrogen sulfide, carbon dioxide and carbon monoxide. “When the algae comes into contact with heavy metals, these gases turn the seaweed into hazardous waste,” Amaro stated a few days ago.
This issue isn’t exclusive to Mexican beaches. Last week, the Dominican Republic also released a report highlighting the threat posed by highly polluted sargassum washing ashore.
The study, conducted by INTEC University, concluded that current seaweed “cannot be repurposed for agricultural use due to its high concentration of toxic elements, which pose risks to both animals and humans.”
“The concentration of arsenic in the sargassum species arriving on the country’s beaches exceeds the international limits established for agricultural use and animal feed,” reads a paper published in the scientific journal Marine Pollution.
Amaro Mauricio has emphasized that the best strategy to minimize health risks is by collecting the algae while it’s still in the open sea.
Solving the sargassum issue requires a multi-pronged approach: continuous satellite monitoring, improving clean-up technologies that don’t erode beaches, promoting companies that convert seaweed into products like biofuels or fertilizers and addressing root causes like climate change and ocean eutrophication.
Regional cooperation among affected Caribbean nations is also key to achieving long-term, sustainable solutions.