A. Kelp Forest Belt
B. Pacific Seaweed Belt
C. Great Atlantic Sargassum Belt
D. Indian Ocean Algae Belt
The Great Atlantic Sargassum Belt reached near-record levels in June 2026. NASA satellite observations showed particularly high concentrations in the Caribbean Sea and the Gulf of America.
Sargassum is a type of floating brown seaweed that provides habitat for marine organisms. However, extremely large accumulations can create problems for coastal communities, tourism, and marine ecosystems when the seaweed reaches beaches and decomposes.