Data_Sheet_2_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.

漂泊于大西洋的浮游海藻筏构成了一种复杂的生态系统，其中包含了众多相互关联的物种。当这些海藻筏大规模搁浅时，引发了诸多社会环境问题，包括污染物的流入和人类健康担忧。在本研究中，我们运用元条形码技术，对两个小安的列斯群岛（瓜德罗普岛和马提尼克岛）上存在的海藻所关联的真菌界和原核界群落进行了差异分析。我们发现，登陆海藻、周边海水以及内陆储存地海藻的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（OTUs）和17,679个真菌界OTUs。在功能预测分析中，我们发现一些原核生物可能对有机物质分解、氮循环和气体产生有所贡献，包括沿海登陆点的硫酸盐还原菌和内陆储存地的产甲烷古菌。此外，我们还发现多细胞动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特或特定的丰富度和丰度模式。这些关于微生物和 meiofauna 群落的分子清单，为沿海和内陆储存地进一步的群落相互作用、藻类有机物质分解和营养物质的转移特征描述提供了基础信息。