Sailing together: A review of the pelagic Sargassum microbiome

Pelagic Sargassum, denoting the two species S. natans and S. fluitans, has become a focal point of both scientific and public interest due to recent superbloom events. As a result, investigation into the dynamics of Sargassum-associated microbiota, which was previously quite limited, has regained momentum in the past five years. This review collates the current state of knowledge relating to the Sargassum microbiome as well as synthesizes relevant biogeochemical findings which may aid future efforts in this field. We explore microbiome composition and functional roles within this holobiont, specifically in terms of taxonomic diversity, macronutrient cycling, and the fate of Sargassum-derived organic matter. Despite progress, significant gaps remain in our understanding of the dynamic interactions within these microbial communities and their broader ecological significance. Future research directions are identified alongside recommendations for standardized protocols, emphasizing the need for more in-depth studies utilizing advanced molecular and biogeochemical techniques to unravel the full complexity of the Sargassum microbiome.