微塑料（microplastics, MPs）是人类社会的重要产物，对地球碳循环的影响作用日益显著。海面上漂浮的MPs与已进入海洋的MPs估值之间存在着巨大偏差，因此详细研究海洋MPs的沉积特性是必不可少的。冷泉是富含甲烷流体渗漏的典型地质现象，孕育典型的依赖甲烷生存的化能合成生态系统。本研究采集了冷泉沉积物进行实验研究，实验结果表明，在冷泉的沉积物中存在16种小粒径（<100 μm）MPs，且甲烷渗漏区域的表层沉积物的MPs丰度高于非渗漏区域，表明甲烷渗漏活动有利于MPs的富集、破碎、多样性变化和老化等作用。与此同时，粗糙的MPs表面可促进参与甲烷氧化的电子受体如铁元素的富集，而铁氧化物与甲烷的厌氧氧化（AOM）密切相关。AOM效率决定了海底渗出的甲烷（能否进入大气层，对全球甲烷循环产生至关重要的影响。因为甲烷在20年内的温室效应是CO2的83倍，且深海环境富含天然气水合物，是地球上最大的甲烷储存库。

Microplastics (MPs) are important exempla of the Anthropocene and are exerting an increasing impact on Earth’s carbon cycle. The huge imbalance between the MPs floating on the marine surface and those that are estimated to have been introduced into the ocean necessitates a detailed assessment of marine MP sinks. Here, we demonstrate that cold seep sediments, which are characterized by methane fluid seepage and a chemosynthetic ecosystem, effectively capture and accommodate small-scale (< 100 μm) MPs, with 16 types of MPs being detected. The abundance of MPs in the surface of the sediment is higher in methane-seepage locations than in non-seepage areas. Methane seepage is beneficial to the accumulation, fragmentation, increased diversity, and aging of MPs. In turn, the rough surfaces of MPs contribute to the sequestration of the electron acceptor ferric oxide, which is associated with the anaerobic oxidation of methane (AOM). The efficiency of the AOM determines whether the seeping methane (which has a greenhouse effect 83 times greater than that of CO₂ over a 20-year period) can enter the atmosphere, which is important to the global methane cycle, since the deep-sea environment is regarded as the largest methane reservoir associated with natural gas hydrates.