Sargassum within the Atlantic has reached report ranges in 2025, with an estimated quantity of 31 million metric tons, in accordance with the Sargassum Watch System (SaWS), an initiative of the Faculty of Marine Science on the College of South Florida (USF). This marks a 40% improve over the earlier report set in June 2022.
Stretching over 5,500 nautical miles from the west coast of Africa to the Gulf of Mexico, this large belt of floating algae is affecting key areas of the Caribbean, in addition to the Florida shoreline, together with the Florida Keys, Key Biscayne, and different in style vacationer areas. Satellite tv for pc imagery launched by USF and NOAA Coral Reef Watch illustrates the huge extent of this bloom, which is predicted to proceed increasing within the coming months.
The proliferation of this marine macroalgae poses environmental, well being, and financial challenges, notably for tourism-dependent locations in Mexico, the United States, and the Caribbean islands. Researchers from each the U.S. and Mexico attribute the expansion of sargassum to a mixture of components, together with local weather change, extreme fertilizer use, and nutrient runoff from main river basins such because the Amazon and the Mississippi.
Unprecedented Quantity in 2025
The College of South Florida reported that in April 2025, the full quantity of sargassum within the central and western tropical Atlantic reached roughly 31 million metric tons. This knowledge, gathered by way of satellite tv for pc and processed by means of the SaWS system, represents the very best degree recorded since monitoring started in 2011.
In keeping with Brian LaPointe, a researcher on the Harbor Department Oceanographic Institute of Florida Atlantic College, this yr’s improve represents roughly 40% extra than the 2022 peak. In feedback reported by CNN, LaPointe famous that the expansion season remains to be ongoing, which means the quantity might proceed to rise.
The densest concentrations have been detected within the central and western Atlantic, drifting with ocean currents towards the Caribbean Sea, the Gulf of Mexico, and the jap coast of the US. Important patches have additionally been noticed off the coast of Brazil and alongside the Lesser Antilles.
Affect on Florida, Mexico, and the Japanese Caribbean
Current updates from NOAA Coral Reef Watch and native media shops akin to The Miami Herald point out that sargassum has already begun affecting Florida’s east coast, with seen buildups on seashores akin to Miami Seashore and harbors like Dinner Key Marina. Photographs taken on Could 8 present giant lots of algae surrounding boats and washing ashore.
In Mexico, the Secretariat of Ecology and Atmosphere (SEMA) of Quintana Roo has deployed greater than 9 kilometers of floating limitations off the coast of Playa del Carmen, Puerto Morelos, and Mahahual to restrict sargassum landfall. Governor Mara Lezama shared by way of social media that these efforts are being coordinated with the Mexican Navy (SEMAR), which can also be conducting offshore assortment operations.
Different impacted areas embrace jap Caribbean islands akin to Barbados, Guadeloupe, and Dominica, the place native tourism associations have reported a decline in lodge bookings as a result of presence of sargassum on seashores, in accordance with the Caribbean Alliance for Sustainable Tourism.
