Dorado Outcrop marine sediment Metagenome

Low-temperature ridge-flank hydrothermal systems are a major source of crustal heat loss into the ocean. However, the effect of the elevated temperatures and altered vent fluids characteristic of this regime on the overlying sediment microbiome has not been studied. Dorado Outcrop is a site of focused low-temperature hydrothermal fluid venting from a 23-mya ridge-flank on the Cocos Plate. Previous community characterization indicates that conditions associated with this system drastically alter the microbial community composition relative to surrounding sediments. This suggests that metabolic potential differs as well, indicating a microbial role in biogeochemical cycling dissimilar to that in hydrothermally unaffected sediments. Objectives of this proposed study are to use metagenomic sequencing to: 1. Evaluate sediment community metabolic potential across Dorado Outcrop in two sites on the Dorado outcrop. 2. Compare this to surrounding microbial communities near Dorado Outcrop 3. Correlate these differences in heat and geochemical regimes associated with the low- temperature hydrothermal venting. PI Laura Zinke, University of Southern California