Florida, Caribbean Face Massive Seaweed Invasion

This summer, get ready for your beach vacation to be a little messier. Seaweed is predicted to build up along the Gulf coastline in the United States, particularly the Sargassum type known for its foul odor. As of April 2025, satellite data shows that this floating algae has reached unprecedented levels in the Atlantic Ocean, far exceeding historical averages.

The seaweed is choking beaches, repelling tourists, and triggering a scramble among scientists and coastal communities for solutions. 

A Record-Breaking Year in the Atlantic

According to marine researchers monitoring satellite imagery, Sargassum concentrations in April 2025 were higher than any previous April on record. The recorded amount of seaweed floating in the Atlantic was 200% higher than at any other point for this time of year.

Dr. Brian Barnes and his team at the University of South Florida’s Optical Oceanography Lab, home of the Sargassum Watch System, have been tracking the bloom closely. The lab uses data from NASA, NOAA, and other satellite networks to monitor Sargassum growth and movement in near real time. What they’re seeing is unprecedented. “There’s a vast mass of Sargassum still offshore,” Barnes noted, “and much of it is making its way toward Caribbean coastlines and the U.S. Southeast.”