The Xiamen Symposium on Marine Environmental Sciences (XMAS 2025)

Pelagic Sargassum, a brown macroalgae of significant ecological importance in the Atlantic Ocean, has increased in recent years, particularly in the Tropical Atlantic and the Intra-Americas Sea (including the Caribbean Sea and the Gulf of Mexico). While Sargassum provides numerous ecological benefits, large Sargassum beaching events have detrimental impacts on human health, local tourism, and coastal ecosystems.

Based on long-term (2000–2023) satellite altimetry and ocean color observations, this study reveals that the transport and spatial distribution patterns of pelagic Sargassum in the Gulf of Mexico are strongly influenced by the complex interplay of ocean eddies and surface currents. We further examine whether mesoscale eddies in the Tropical Atlantic and Caribbean Sea can entrain Sargassum and potentially contribute to its long-distance dispersal. Our analysis shows that cyclonic eddies are more effective at entraining Sargassum compared to anticyclonic eddies and eddy-free waters, with this influence varying by location. Additionally, larger and stronger eddies, such as North Brazil Current rings and eddies in the Caribbean Sea, demonstrate a greater capacity for Sargassum entrainment.

These findings not only contribute to our understanding of the interactions between mesoscale oceanographic processes and Sargassum distributions, but also offer valuable insights on how to mitigate the impacts of Sargassum inundations, for example through targeted physical removal.
 

mesoscale eddies, sargassum, Tropical North Atlantic Ocean