资源环境科技发展态势分析平台

Cold seeps represent hot spots of seabed-derived methane emissions to the water column, where physical and biological barriers regulate transport of methane to the atmosphere. In our study, we used a methane point source in the North Sea to investigate water-column methane dynamics within the dispersing plumes. The study is based on methane concentration, distribution and activity of methane-oxidizing bacteria (MOB), and oceanographic observations. Our findings suggest the ejection of benthic MOB into the water column by sediment resuspension and gas-bubble-mediated transport. An applied particle-tracking model demonstrated that the ejection of 4.29 ± 1.9 x 10¹² MOB cells s⁻¹ from the seep site would produce the MOB abundance detected in the down-current water body. The benthic MOB inoculant accelerated methane oxidation rates by a factor of five. Our study highlights the importance of the bentho-pelagic transport of microorganisms at seep sites and their feedback on the pelagic methane sink.