Metabarcoding data from microbial diversity survey at Axial Seamount aboard the R/V Thompson cruise TN420 in Jul 2022 and Jul 2023

Microorganisms are the ancestral forms of life on our planet and have been instrumental in shaping all of Earth's environments into what they are today. In the ocean, microbial prokaryotes and eukaryotes form the foundation of marine food webs through their activity and interactions. Single-celled microbial eukaryotes (or protists) are some of the most important species on the planet, yet our understanding of how their activities influence and regulate the ocean ecosystem is poorly constrained. At deep-sea hydrothermal vents in particular, our understanding of microbial food web dynamics is incomplete without including the role of microbial eukaryotes. In July 2023, we completed an ROV expedition to Axial Seamount (NE Pacific), where we used ROV Jason to collect low temperature diffuse vent fluid and surrounding plume and background seawater. These samples were filtered in situ or shipboard to collect the microbial communities. Data provided are the product of amplicon tag-sequencing using both 18S rRNA and 16S rRNA gene primers.