Seismic events as potential drivers of the microbial community structure and evolution in a paleo-ocean analog

Anthropogenic perturbations profoundly affect aquatic ecosystem microbiomes and associated ecological functions. Comparatively, the effects of geological stresses on microbiome composition and stability remain poorly explored. Here, we monitored the archaeal, bacterial and microeukaryotes community structure over an 8-years period in Lake Dziani Dzaha (Comoros archipelago), that experienced a major earthquake swarm mid-survey, providing a rare opportunity to investigate the aftermaths of seismo-volcanic events on microbiome. Our results revealed the sensitivity of the aquatic microbial community towards seismicity and associated environmental changes, that triggered a major shift in microbiome composition and abundance with persisting consequences on structure and richness of the microbial ecosystem. Our findings suggest that seismological perturbations could be major drivers of the microbial community structure in aquatic environments through cascading effects on environmental conditions. Over geological time scales, such events may have been significant yet underestimated forces driving diversification and evolution of microbial communities. An 8-year-long observational study of Lake Dziani Dzaha in Mayotte, an analog for the Proterozoic ocean, suggests seismo-volcanic events can perturb geochemical variables and trigger shifts in the composition and structure of the microbiome.