Table_2_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，由众多相关物种构成，形成了复杂的生态系统。当这些海藻筏大规模搁浅时，会导致一系列社会环境问题，包括污染物涌入和人类健康担忧。在本研究中，我们采用了元条形码技术，对两个小安的列斯群岛（瓜德罗普和马提尼克）上的海藻中存在的真核生物和原核生物相关群落进行了差异分析。我们发现，在登陆的海藻、周围海水以及内陆储存地海藻之间，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个原核生物操作分类单元（OTU）和17,679个真核生物OTU。在功能预测分析中，我们发现一些原核生物可能参与有机物分解、氮循环和气体产生，包括沿海登陆地的硫酸盐还原菌和内陆储存地的产甲烷古菌。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呈现出独特的或特定的丰富度和丰度模式。综上所述，这些微生物和中生动物群落分子鉴定为沿海和内陆储存地进一步研究营养相互作用、藻类有机物分解和营养传递提供了基础信息。