SARGASSUM ORIGINS

Sargassum inundation has caused major ecological, economical and societal damage in the Caribbean since 2011. The massive strandings are associated with the extensive occurrence of Sargassum aggregations in the Tropical North Atlantic. The Sargassum Origins project is an integrative framework designed to understand processes behind the expansion of holopelagic Sargassum populations in the Caribbean region. The first objective of this project is thus to clearly identify the Sargassum species growing in the North Atlantic and determine to what extent the species co-occur, with a particular focus on the species involved in inundations. The second objective is to study the connectivity of Sargassum at the Atlantic-scale, with a focus on the fluxes and exchanges that are occurring between the historical Sargasso Sea and the new area of proliferation. The hypothesis of a clonality of the pelagic species will be particularly studied. The role of the rivers (Amazonian rivers, African rivers) in the proliferation of the Sargassum is regularly argued, thus a third objective is to elucidate the origin of the nutrient inputs in the carbon and nitrogen Sargassum pathways.