Dataset: Accession numbers for metagenome-assembled genomes (MAGs) from samples collected in 2018 on R/V Thompson cruise TN350 at the Upper and Lower Cones, Upper Caldera Wall and NW Caldera, Brothers Volcano

Water samples and hydrothermal vent deposits were collected as described in Reysenbach & St. John et al., 2020. Samples were collected with remotely operated vehicle ROV Jason. Water samples were obtained using major water samplers. Hydrothermal deposits were placed in sealed bioboxes in the ROV sampling basket to restrict flushing of samples by surrounding seawater during the ascent. Once shipboard, 1L of water samples were filtered through a 0.2-μm Sterivex filter (Merck). For the hydrothermal deposits, the outer few millimeters (up to approximately 5 mm) was subsampled for DNA extraction. These exterior samples were homogenized and stored in cryovials at -80 degrees C for subsequent DNA extraction. For the water samples, the DNA was extracted from the sterivex filters as previously described by R. E. Anderson et al. (2017). The DNA was extracted from the homogenized hydrothermal depot samples using the DNeasy PowerSoil kit (Qiagen) All purified environmental DNA was stored at -80 degrees C. After DNA extraction and library preparation, metagenomes were sequenced using the Illumina HiSeq 3000.