Abstract:
Historically, our understanding of bacterial ecology in the Indian Ocean has been limited to regional studies that place emphasis on community structure and function within oxygen minimum zones. Thus, bacterial community dynamics across the wider Indian Ocean are largely undescribed. As part of Bio-GO-SHIP, we sequenced the 16S rRNA gene from 465 samples collected on sections I07N and I09N. We found that (i) there were 23 distinct bioregions within the Indian Ocean, (ii) the southeastern gyre had the largest gradient in bacterial alpha-diversity, (iii) the Indian Ocean surface microbiome was primarily composed of a core set of taxa, and (iv) bioregions were characterized by transitions in physical and geochemical conditions. Overall, we showed that bacterial community structure spatially delineated the surface Indian Ocean and that these microbially-defined regions were reflective of subtle ocean physical and geochemical gradients. Therefore, incorporating metrics of in-situ microbial communities into marine ecological regions traditionally defined by remote sensing will improve our ability to delineate warm, oligotrophic regions.
摘要:
历史上,我们对印度洋细菌生态学的理解仅限于区域研究,这些研究着重于最小氧气区域内的群落结构和功能。因此,整个印度洋的细菌群落动态基本上没有描述。作为Bio-GO-SHIP的一部分,我们从I07N和I09N切片上收集的465个样品中对16SrRNA基因进行了测序。我们发现(i)印度洋内有23个不同的生物区域,(ii)东南环流的细菌α多样性梯度最大,(iii)印度洋表面微生物组主要由一组核心分类群组成,和(iv)生物区域的特征是物理和地球化学条件的转变。总的来说,我们表明,细菌群落结构在空间上描绘了印度洋表面,这些微生物定义的区域反映了微妙的海洋物理和地球化学梯度。因此,将原位微生物群落的指标纳入传统上由遥感定义的海洋生态区域将提高我们描绘温暖的能力,贫营养地区。