Sediment depth impacts microbial community structure in methane seepage regions

Deep-sea methane seepage and associated microbial activities are a crucial part of balancing the global methane budget. However, there is a limited understanding of the various response mechanisms of prokaryotic microorganisms in methane seepage sediments from different depths, which hinders the accurate characterization of the cold seep methane budget. This study investigated the diversity, ecological clustering, and community assembly processes of microorganisms from different sediment depths in methane seepage sediments from the Haima Cold Seep. The results show that a significant correlation was observed between methane, sulfate, total inorganic carbon, total organic carbon, and depth in methane seepage environments (P < 0.05). We also determined that sediment depth affected the carbon, and sulfur cycling processes, particularly at 10 and 70 cm of the sediment. The methane leakage region was dominated by deterministic processes in the vertical profiles. The concentrations of methane, total inorganic carbon, and sulfate were key drivers in microbial community structure. This research provides novel insights into how microorganisms in deep-sea methane seepage environments adapt to their surroundings, establish communities, and patterns of coexistence in shared habitats. In methane seepage regions, sediment depth is correlated with methane, sulphate, and total inorganic carbon, all of which influence microbial community structure, according to analyses of sediment cores from the Haima cold seep.