Data_Sheet_3_Sargassum Differentially Shapes the Microbiota Composition and Diversity at Coastal Tide Sites and Inland Storage Sites on Caribbean Islands.PDF

Rafts of drifting pelagic Sargassum that are circulating across the Atlantic Ocean are complex ecosystems composed of a large number of associated species. Upon massive stranding, they lead to various socio-environmental issues including the inflow of contaminants and human health concerns. In this study, we used metabarcoding approaches to examine the differences in both the eukaryotic- and prokaryotic-associated communities from Sargassum present in two islands of the Lesser Antilles, namely Guadeloupe and Martinique. We detected significant differences in microbial community structure and composition between landing Sargassum, the surrounding seawater, and Sargassum from inland storage sites. In total we identified 22,214 prokaryotic and 17,679 eukaryotic OTUs. Among them, functional prediction analyses revealed a number of prokaryotes that might contribute to organic matter decomposition, nitrogen cycling and gas production, including sulfate-reducing bacteria at coastal landing sites, and methanogenic archaea at inland storage sites. We also found that Metazoan was the most abundant group in Sargassum samples, with nematode clades that presented exclusive or specific richness and abundance patterns depending on their Sargassum substrate. Together, these molecular inventories of the micro- and meiofauna communities provide baseline information for further characterization of trophic interactions, algal organic matter decomposition and nutrient transfers at coastal and inland storage sites.

漂泊于大西洋的漂流海藻筏群构成复杂的生态系统，其中聚集了大量的相关物种。在大量搁浅的情况下，它们引发了诸多社会环境问题，包括污染物的涌入和对人类健康的担忧。在本研究中，我们采用了元条形码技术来分析来自小安的列斯群岛的两个岛屿——瓜德罗普和马提尼克——上存在的海藻中，真核生物和原核生物关联群之间的差异。我们在登陆的海藻、周围的海水和内陆储存地点的海藻之间检测到了微生物群落结构和组成的显著差异。总计我们鉴定出22,214个原核生物OTUs和17,679个真核生物OTUs。其中，功能预测分析揭示了若干可能参与有机物分解、氮循环和气体生产的原核生物，包括沿海登陆地点的硫酸盐还原菌和内陆储存地点的产甲烷古菌。我们还发现，在海洋藻类样品中，多细胞生物是数量最丰富的群体，其中线虫类群根据其海藻基质的种类呈现了独特或特定的丰富度和丰度模式。综上所述，这些微生物和 meiofauna 群落的分子清单为沿海和内陆储存地点的摄食相互作用、藻类有机物分解和营养物质的迁移提供了基础信息。