Table_3_Sargassum Differentially Shapes the Microbiota Composition and Diversity at Coastal Tide Sites and Inland Storage Sites on Caribbean Islands.XLSX

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.

漂浮于大西洋的漂泊性海藻筏群构成了由众多相关物种组成的复杂生态系统。在发生大规模搁浅时，它们引发了包括污染物流入和人类健康担忧在内的多种社会环境问题。在本研究中，我们运用宏条形码技术，对存在于小安的列斯群岛的两个岛屿——瓜德罗普和马提尼克——的海藻中的真核生物和原核生物关联群落进行了差异分析。我们发现，在登陆海藻、周围海水以及内陆储存地点的海藻之间，微生物群落结构和组成存在显著差异。总计我们鉴定出了22,214个原核生物OTUs和17,679个真核生物OTUs。在功能预测分析中，我们发现了一些可能参与有机物分解、氮循环和气体生成的原核生物，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。此外，我们还发现，多细胞生物是海藻样本中最丰富的类群，其中线虫类群根据其海藻基质的差异展现出独有的或特定的丰富度和丰度模式。这些关于微生物和中生动物群落组成的分子清单，共同为沿海和内陆储存地点的营养相互作用、藻类有机物分解以及营养物质的迁移提供了基础信息。