Sargassum Tracker

USF OOL Long Term Outlook

Jul 31, 2025
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In August 2025, although total Sargassum amount decreased from July in each of the 5 regions, the absolute amount still exceeded the historical record for August. Yet the amount will continue to decrease in the next 2-3 months to reach the annual minimum.

Looking ahead: As in previous years, the momentum of Sargassum decline is likely to continue in the coming months, possibly reaching the annual minimum around October – November. However, because the absolute amount is still much higher than any previous August, Sargassum inundation of variable degree will continue to occur in most of the Caribbean nations and islands. However, whether a beach or small region receives large amount of Sargassum depends on local factors that are difficult to predict, including winds and ocean currents. One such example is the southeast coast of Florida: although total Sargassum in the Gulf of America exceeded the historical record for 3 consecutive months, Sargassum inundation was not as severe as in some of the previous years, due mainly to the specific positions of the Loop Current and its eddies. More info : Sargassum Watch System (SaWS).

SARGASSUM ABUNDANCE INTENSITY

Details

Since 2011, large amounts of Sargassum seaweed have appeared in the Caribbean Sea every summer except 2013, creating many environmental, ecological, and economic problems in many regions. The seaweed originated from the tropical Atlantic and is believed to be a result of climate variability and other natural and unnatural processes. Based on satellite observations and statistics of historical events, in early February 2018, the Optical Oceanography Lab developed the first 1-page Sargassum outlook bulletin for the Caribbean Sea. Since then, the bulletins have been generated and distributed to subscribers by the last day of the month. These monthly bulletins are also made available at the bottom of the SaWS page.

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Disclaimer

The information bulletin is meant to provide a general outlook of current bloom condition and future bloom probability for the Caribbean Sea. By no means should it be used for commercial purpose, or used for predicting bloom conditions for a specific location or beach. The authors of this bulletin, as well as Caricoos, USF and NASA, take no responsibility for improper use or interpretation of the bulletin. Any use of the image, data, or graph from this bulletin page in reports or publications should obtain permission from the USF OOL group.