Map of shallow sea hydrothermal vents. (a) The hydrothermally active islands of Milos, Santorini, and Nisyros are located along the Hellenic Volcanic Arc. (b) Samples were collected in 2011 from shallow (~5 m water depth) submarine hydrothermal sites in Palaeochori Bay. The shaded areas represent the areal extent of hydrothermal activity (34 km2) observed around Milos . Figures modified from previous Milos studies ,.