Pelagic Sargassum seaweed is a large brown alga floating at the ocean surface thanks to its gas-filled bladders. In the North Atlantic, this alga grows and stays at the sea surface during its entire lifetime, aggregating and forming mats carried by winds, waves and currents on very long distances. Massive stranding episodes have increased in periodicity and intensity in the Caribbean Sea, summer 2018 being the historical record so far.  Once on the beaches, the rafts rot and decompose, leading to dramatic consequences on the environment, tourism economy and human health. 

Monitoring those disastrous events is more and more important, but their forecasting is rather complex, due to its irregularity: mechanisms at stake in the apparition and arrival of the rafts on shores still need more studies. In situ observation – drones or boats – constitute key tools to quantify the algae amount available for stranding, but their coverage in space and time remains limited. With their high spatial and temporal resolution and coverage, ocean colour satellites belonging to the Copernicus programme can help filling in the gaps and offer a simple and powerful way of detecting Sargassum rafts. 

In this webinar, we will use the free and open data provided by the OLCI instrument on board the Sentinel-3 mission, and process them with the SNAP software to detect and map Sargassum rafts in the Caribbean Sea.

You can replay this webinar through our RUS Copernicus Training channel available on Youtube.

You can also retrieve the corresponding training support in the Train with RUS section of the RUS portal.


RUS Webinar – Sargassum mapping in the Caribbean using Sentinel-3 – 26 Aug. 2021