Biodiversity and biogeography of hydrothermal vent species : thirty years of discovery and investigations

Author Posting. © Oceanography Society, 2007. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 20, 1 (2007): 30-41.The discovery of hydrothermal vents and the unique, often endemic fauna that inhabit them represents one of the most extraordinary scientific discoveries of the latter twentieth century. Not surprisingly, after just 30 years of study of these remarkable—and extremely remote—systems, advances in understanding the animals and microbial communities living around hydrothermal vents seem to occur with every fresh expedition to the seafloor. On average, two new species are described each month—a rate of discovery that has been sustained over the past 25–30 years. Furthermore, the physical, geological, and geochemical features of each part of the ridge system and its associated hydrothermal-vent structures appear to dictate which novel biological species can live where. Only 10 percent of the ridge system has been explored for hydrothermal activity to date (Baker and German, 2004), yet we find different diversity patterns in that small fraction. While it is well known that species composition varies along discrete segments of the global ridge system, this “biogeographic puzzle” has more pieces missing than pieces in place.E. Ramirez-Llodra is supported by the ChEss-Census of Marine Life program (A.P. Sloan Foundation), which is kindly acknowledged. C.R. German also acknowledges support from ChEss- Census of Marine Life and further support from the Natural Environment Research Council (UK) and from the US National Science Foundation (NSF) and National Oceanic and Atmospheric Administration (NOAA). T. Shank acknowledges support from NSF, the US National Aeronautic and Space Administration Astrobiology Program, NOAA-Ocean Exploration, and the Deep-Ocean Exploration Institute at the Woods Hole Oceanographic Institution