Next-generation sequencing data across a hydrothermal gradient; Okinawa Backarc Basin IODP 331 – subvent biosphere. RNA extractions were attempted from sediments at Sites C0014 and C0017 to selectively investigate the active microbial populations at these sites. This study was conducted to supplement the gene-based and metagenomic studies. However, the results from sequenced reverse transcribe 16S rRNA demonstrate the sensitivity of extraction and amplification to external nucleic acids and attest to the challenges in working with low biomass environmental samples. Inconsistencies between primersets and replicates make conclusions about the results of this RNA study extremely tenuous.