Sediment microbial communities at CO2 seeps in Papua New Guinea

To understand how ocean acidification (OA) influences sediment microbial communities, naturally CO2-rich sites are increasingly being used as OA analogues. However, the characterization of these naturally CO2-rich sites is often limited to OA-related variables, neglecting additional environmental variables that may confound OA effects. Here, we used an extensive array of sediment and bottom water parameters to evaluate pH effects on sediment microbial communities at hydrothermal CO2 seeps in Papua New Guinea. The geochemical composition of the sediment pore water showed variations in the hydrothermal signature at seep sites with comparable pH, allowing the identification of sites that may better represent future OA scenarios. At these sites, we detected a 60% shift in the microbial community composition compared with reference sites, mostly related to increases in Chloroflexi sequences. pH was among the factors significantly, yet not mainly, explaining changes in microbial community composition. pH variation may therefore often not be the primary cause of microbial changes when sampling is done along complex environmental gradients. Thus, we recommend an ecosystem approach when assessing OA effects on sediment microbial communities under natural conditions. This will enable a more reliable quantification of OA effects via a reduction of potential confounding effects.
This pangaea entry contains the data on the microbial community structure and bottom water parameters.

为了解海洋酸化（Ocean Acidification, OA）如何影响沉积物微生物群落，富含天然CO₂的研究位点正日益被用作OA的模拟体系。然而，此类富含天然CO₂的研究位点的特征描述通常仅局限于与OA相关的环境变量，忽略了可能干扰OA效应解析的其他环境变量。本研究以巴布亚新几内亚的热液CO₂喷口区为研究对象，通过采集大量沉积物与底层水环境参数，评估pH对沉积物微生物群落的影响。沉积物孔隙水的地球化学组成分析显示，pH相近的喷口位点间存在热液信号差异，据此可筛选出更能代表未来OA情景的研究位点。在这类筛选出的位点中，我们检测到微生物群落组成相较于对照位点发生了60%的变化，该变化主要与绿弯菌门（Chloroflexi）序列丰度的提升相关。pH是显著影响微生物群落组成变化的因素之一，但并非主导因素。因此，当沿复杂环境梯度开展采样研究时，pH变化往往并非微生物群落改变的首要诱因。据此，我们建议在自然条件下评估OA对沉积物微生物群落的影响时，应采用生态系统研究范式，此举可通过降低潜在干扰效应的影响，实现对OA效应更可靠的定量分析。
本Pangaea数据集条目收录了微生物群落结构与底层水环境参数相关数据。