The protection of the deep-sea ecosystems, the largest biome on the planet, is crucial for future generations and requires ambitious research projects. The deep ocean, covering more than 70% of the Earth’s surface, is a major source of oxygen and carbon dioxide absorption. It has attracted the attention of countries for its biodiversity and mineral resources, particularly in hydrothermal contexts. It is urgent to establish solid knowledge bases to manage these ecosystems within an interconnected framework.

Since 2011, the French West Indies have been confronted with mass strandings of holopelagic algae of the genus Sargassum. The ISABIO project aims to assess the impact of Sargassum mass strandings on the biodiversity of coastal marine ecosystems (coral reefs, seagrass beds, mangroves) and littoral ecosystems (beaches, backshore storage areas). Two sampling campaigns will be carried out at the proposed study sites. Biodiversity can thus be compared before and after the passage and beaching of Sargassum rafts on the coast.