Stimulated Organic Carbon Cycling and Microbial Community Shift Driven by a Simulated Cold-Seep Eruption

Abstract

In the ocean, almost all of the emission and consumption of deeply buried methane occurs in cold seeps; therefore, understanding the methane cycling in cold seeps is crucial to estimating the oceanic methane budget. Cold-seep eruptions often lead to the dramatic destruction of microbial ecosystems that drive methane cycling. Because of technical challenges, the direct monitoring of these communities as well as the activity shifts during eruptions has never been achieved. In this study, we took an alternative approach by simulating cold-seep eruptions and using genome-resolved metagenomics to interpret the dynamic changes in the microbial community. The results show that the periodical cold-seep eruptions intensify organic carbon cycling, undermine the direct oxidation of methane to carbon dioxide, and drive microbial community shifts. These results further suggest that a more sophisticated calculation of the methane budget in cold seeps that considers their eruption status is needed.