USF College of Marine Science

NASA

Sizing Up the Sargassum Belt

Sargassum, a type of brown floating algae, has shifted its range in recent decades, thinning out in the North Atlantic’s Sargasso Sea while proliferating in the tropical Atlantic. That trend, underway since 2011, continued in 2026 as the algae, commonly known as a type of seaweed, reached its annual peak in June across a stretch of ocean known as the Great Atlantic Sargassum Belt.…