Carla Botelho Machado1, Gina-Marie Maddix2, Patrice Francis2, Shanna-Lee Thomas3, Jodi-Ann Burton4, Swen Langer5, Tony R. Larson5, Robert Marsh6, Mona Webber2, Thierry Tonon1
1Centre for Novel Agricultural Products (CNAP), Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom.
2Centre for Marine Sciences, 1 Anguilla Close, University of the West Indies, Mona, Kingston 7, Jamaica.
3Discovery Bay Marine Laboratory, Queen’s Highway, Discovery Bay, Jamaica.
4Port Royal Marine Laboratory, Port Royal, Kingston 1, Jamaica.
5Metabolomics and Proteomics Lab, Bioscience Technology Facility, Department of Biology, University of York, Heslington, York YO10 5DD, United Kingdom.
6School of Ocean and Earth Science, University of Southampton Waterfront Campus, National Oceanography Centre, European Way, Southampton, SO14 3ZH, UK.
Pelagic sargassum have been known for centuries in the Sargasso Sea of the North Atlantic Ocean. In 2011, a new area concentrating high biomass of these brown algae started developing in the Tropical Atlantic Ocean. Since then, massive and recurrent sargassum influxes have been reported in the Caribbean and West Africa. These events negatively impact coastal ecosystems and nearshore marine life, and affect public health, coastal living, tourism, fisheries, and maritime transport. Despite recent advances in the forecasting of sargassum events and elucidation of the seaweed composition, many knowledge gaps remained, including morphotype abundance during sargassum events, drift of the seaweeds prior to stranding, and influence of sample processing on biomass composition. Analysis of samples harvested on the coasts of Jamaica in summer 2020 showed that S. fluitans III was the most abundant morphotype. No clear difference in the geographical origin of the sargassum mats was observed. The majority of sargassum backtracked from both north and south of Jamaica experienced ambient temperatures of around 27 °C and salinity in the range of 34-36 psu before stranding. Cheap (sun) compared to expensive (freeze) drying techniques influenced biomass biochemical composition. Sun-drying increased the proportion of phenolic compounds, but had a deleterious impact on fucoxanthin and monosaccharide content, except for mannitol. Effects on fucose containing sulfated polysaccharides content depended on their extraction method. Limited variation was observed in ash, protein, and fatty acid content. Such information is important for the storage and transport of the biomass in the context of its valorisation.