Viruses are the most abundant biological entities on Earth. Metagenomic data indicates a higher viral abundance of viruses of unicellular eukaryotes in the polar regions, information still not matched by broad isolation efforts using samples collected in these regions. Here we describe a prospection effort using diverse samples collected above the Arctic circle, including freshwater and marine samples from urban areas, deep‐se...

To meet future demands, mineral resources found in deposits along mid-ocean ridges have triggered the interest of the deep-sea mining industry. Comprehensive environmental management regulations are being developed by the International Seabed Authority (ISA) to control the exploitation of seabed areas beyond national jurisdiction. Norway has recently opened its seabed to mining exploration, which may potentially lead to future...

Evidence of hydrothermal venting on the ultra-slow spreading Gakkel Ridge in the Central Arctic Ocean has been available since 2001, with first visual evidence of black smokers on the Aurora Vent Field obtained in 2014. But it was not until 2021 that the first ever remotely operated vehicle (ROV) dives to hydrothermal vents under permanent ice cover in the Arctic were conducted, enabling the collection of vent fluids, rocks, m...

Summary Little is known about how lithoautotrophic primary production is connected to microbial organotrophic consumption in hydrothermal systems. Using a multifaceted approach, we analysed the structure and metabolic capabilities within a biofilm growing on the surface of a black smoker chimney in the L oki's C astle vent field. Imaging revealed the presence of rod‐shaped B acteroidetes growing as ectobionts on long, sheathed...

Summary Deep‐sea hydrothermal vents are unique environments on E arth, as they host chemosynthetic ecosystems fuelled by geochemical energy with chemolithoautotrophic microorganisms at the basis of the food webs. Whereas discrete high‐temperature venting systems have been studied extensively, the microbiotas associated with low‐temperature diffuse venting are not well understood. We analysed the structure and functioning of mi...

Summary Sulfate‐reducing methanotrophy by anaerobic methanotrophic archaea (ANME) and sulfate‐reducing bacteria (SRB) is a major biological sink of methane in anoxic methane‐enriched marine sediments. The physiology of a microbial community dominated by free‐living ANME‐1 at 14–16 cm below the seafloor in the G11 pockmark at Nyegga was investigated by integrated metagenomic and metaproteomic approaches. Total DNA was subjected...