The arsenic geochemical data and microbial data from sediments in Hama cold seep

Arsenic is a globally significant toxic metalloid and accumulation in seafloor cold seeps, yet its biogeochemical mechanisms remain enigmatic. Through a combination of geochemical and metagenomic analyses, we demonstrate that anaerobic oxidation of methane and the enhanced 'metal particle shuttle effect' synergistically established cold seeps as significant arsenic sink. Notably, we identify key microbial taxa, particularly <i>Desulfobacterota</i>, play a central role in mediating the coupled processes of sulfate reduction, arsenate reduction, and AOM, thereby facilitating arsenic immobilization. Quantitatively, we preliminarily estimate that cold seeps may sequester 4.53-6.14 × 10⁶ kg of arsenic annually, a flux comparable to hydrothermal inputs. Our findings suggest that methane-driven arsenic sequestration in cold seeps may influence global arsenic cycling, particularly during large-scale methane release events.

砷是一种具有全球意义的有毒类金属（toxic metalloid），在海底冷泉中存在积累现象，但其生物地球化学机制（biogeochemical mechanisms）仍不明确。通过地球化学分析（geochemical analyses）与宏基因组分析（metagenomic analyses）相结合的方法，我们证实甲烷厌氧氧化（anaerobic oxidation of methane, AOM）与增强的"金属颗粒穿梭效应（metal particle shuttle effect）"协同作用，使冷泉成为重要的砷汇（arsenic sink）。值得注意的是，我们识别出关键微生物类群（microbial taxa），尤其是<i>Desulfobacterota</i>，在介导硫酸盐还原（sulfate reduction）、砷酸盐还原（arsenate reduction）及AOM的耦合过程中发挥核心作用，从而促进砷的固定。定量上，我们初步估计冷泉每年可能封存4.53-6.14×10⁶ kg砷，这一通量与热液输入相当。我们的研究结果表明，冷泉中甲烷驱动的砷封存可能影响全球砷循环（global arsenic cycling），尤其是在大规模甲烷释放事件期间。