Pelagic Sargassum in the Gulf of Mexico driven by ocean currents and eddies, Harmful Algae

Pelagic Sargassum in the Gulf of Mexico plays an important role in ocean biology and ecology, yet our knowledge of its origins and transport pathways is limited. Here, using satellite observations of Sargassum areal density and ocean surface currents between 2000 and 2023, we show that large amounts of Sargassum in the Gulf can either originate from the northwestern Gulf or be a result of physical transport from the northwestern Caribbean Sea, both with specific transport pathways. Sargassum of the northwestern Gulf can be transported to the eastern Gulf by ocean currents and eddies, eventually entering the Sargasso Sea. Sargassum entering the Gulf from the northwestern Caribbean Sea can be transported in three different directions, with the northward and eastward transports governed by the Loop Current System and westward transport driven by the westward extension of the Loop Current System, the propagation or relaying of ocean eddies, the wind-driven westward currents on the Campeche Bank with or without eddies, and the westward currents with/without currents associated with eddies in the northern/central Gulf. Overall, the spatial distribution patterns of pelagic Sargassum in the Gulf of Mexico are strongly influenced by the Loop Current System and relevant eddies.

Yingjun Zhang, Chuanmin Hu, Dennis J. McGillicuddy, Brian B. Barnes, Yonggang Liu, Vassiliki H. Kourafalou, Shuai Zhang, Frank J. Hernandez. Pelagic Sargassum in the Gulf of Mexico driven by ocean currents and eddies, Harmful Algae, Volume 132, 2024, 102566. https://doi.org/10.1016/j.hal.2023.102566.

Last updated by Southeast Fisheries Science Center on 01/06/2025

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