Deep‐Sea Hydrothermal Vents

Abstract Hydrothermal vents were first discovered on the Galapagos Rift in 1977, and in the intervening 4 decades we have learned a great deal about these unique oases of life in the cold, dark, high pressure environments of the deep seafloor. Found on mid‐ocean ridges, back‐arc basins, and seamounts around the world, they result from the interaction of cold seawater with oceanic crust that has been superheated by underlying volcanic activity. Hydrothermal fluids leave the seafloor and form sulfide chimneys. These fluids are highly reducing, and contain toxic materials such as hydrogen sulfide, which provides the necessary components of life for the chemoautotrophic organisms forming the base of the food web in these ecosystems. Animals living at these vents have adapted to the harsh conditions by relying on chemoautotrophic microorganisms, either directly as a source of food, or in symbiotic association. They use varied strategies to maintain their symbiotic associations and to thrive at hydrothermal vents. While many animals characterize vent communities, some specific examples including tubeworms, Pompeii worms, mollusks, and crustaceans are described in more detail here. As we learn more about these widely spaced communities biogeographical patterns emerge, increasing our understanding of the evolution of vent communities.