One of the subjects being explored by HERMES is mud volcanoes, and more specifically underwater mud volcanoes. Mud volcanoes are cone-shaped formations of sediment, of variable size. They are composed of a mixture of fluids (generally water and gases) and mud (undercompacted clay), which flow from one or more vent holes in the middle of the crater. During an eruption, mud volcanoes emit large amounts of methane. Mud volcanoes are found on land and underwater. The latter are the subject of this new report for television stations. Indeed, researchers are studying the impact on climate change of the gases emitted by these volcanoes. They have discovered that the immediate surroundings of these volcanoes are constituted of micro-organisms, of which 99% are still unidentified today, and some of which feed on methane, hydrogen sulphide and other gases, preventing them from being released into the sea and consequently rising to the surface. The royalty-free report, available to television stations at no cost, shows barren seabeds at depths of 1700 metres, dominated by underwater mud volcanoes. The report contains interviews with: Silvia Ceramicola, OGS, Italy Jean Mascle, G‰OSCIENCES-AZUR, France Antje Boetius, MAX PLANCK INSTITUTE FOR MARINE MICROBIOLOGY, Germany Riccardo Geletti, OGS, Italy Nigel WardelI, OGS, Italy Daniel Praeg, OGS, Italy