Archaeal communities at gas-venting shallow basins in the northern Gulf of California (Wagner and Consag basins)

Abstract

Deep-sea vents microorganisms have been well characterized with defined typical taxonomic groups, principally composed of archaea, while shallow hydrothermal vents are considered to host a different community with bacteria as predominant prokaryotes. This work focuses on two shallow basins in the northern Gulf of California: Wagner and Consag basins which show evidence of early stages of rifting processes and host numerous submarine vents with intense gas discharge. The exploratory study of archaea and bacteria in six sediment samples from the shallow vents in those basins (average depths of 100 m), demonstrate that similar archaea phyla inhabit these vents. The phylum Thermoproteota with Nitrosopumilus as the most abundant genera in five sites. However, in the sample with the highest temperature, the phylum Asgardarchaeota was predominant, and also the occurrence of archaeal lineages typical of deep sea vents like Nanoarchaeota, Thermoproteota, Euryarchaeota, and members from phylum Asgardarchaeota, were identified. This work is the first report of the presence of a typically deep vent community of archaea in this shallow vent environment.