Community study of hydrotherma vent meiobenthos

Meiobenthos, animals and protists in the size range between 63 m and 1mm, are part of the hydrothermal vent community. One of the best-known midocean ridge areas, 950N, 104 17W East Pacific Rise, has been chosen by the U.S. scientific community and their RIDGE 2000 program as prime study area of a fast-spreading mid-ocean ridge system. This is based on the knowledge gained through 20 years of intense integral research covering all major aspects of geology, geophysics, biochemistry and biology. The macrofauna assemblages there provide microhabitat or refugee for meiobenthos, but at large, the latter composition, distribution and especially its ecological role are unknown. To our knowledge, for the first time in deep-sea hydrothermal vent research, we will characterize the meiofauna of a midocean ridge system. The central objective of this proposed work is to identify and quantify the metazoan and foraminiferan meiobenthic community at East Pacific Rise 950`N hydrothermal vents and the adjacent off-axis sediments so that the species diversity, abundance, biomass, and distribution are documented according to well-characterized habitats within this ecosystem. This study will include the identification of all metazoan and foraminiferan meiobenthic species, the description of new species and the characterization of any microbial symbioses that might be found. It will allow us to distinguish communities within the spreading center (between active and inactive sites, either hard substrate, sulfide precipitates, or soft sediments) and the off axis ridge areas. From these descriptive data, underlying evolutionary and historical processes may be invoked and hypothesis on the origin and evolution of vent meiobenthos can be developed. These data will also enable the estimating of meiobenthic biodiversity and biomass, to distinguish and characterize the meiobenthic communities and to estimate their ecological impact by integrating these data into a broader framework of biological and geochemical studies that are carried out in parallel. Within this framework, the proposed work will greatly increase the understanding of the entire hydrothermal vent community and of interactions therein.

Meiobenthos, animals and protists in the size range between 63 m and 1mm, are part of the hydrothermal vent community. One of the best-known midocean ridge areas, 950N, 104 17W East Pacific Rise, has been chosen by the U.S. scientific community and their RIDGE 2000 program as prime study area of a fast-spreading mid-ocean ridge system. This is based on the knowledge gained through 20 years of intense integral research covering all major aspects of geology, geophysics, biochemistry and biology. The macrofauna assemblages there provide microhabitat or refugee for meiobenthos, but at large, the latter composition, distribution and especially its ecological role are unknown. To our knowledge, for the first time in deep-sea hydrothermal vent research, we will characterize the meiofauna of a midocean ridge system. The central objective of this proposed work is to identify and quantify the metazoan and foraminiferan meiobenthic community at East Pacific Rise 950`N hydrothermal vents and the adjacent off-axis sediments so that the species diversity, abundance, biomass, and distribution are documented according to well-characterized habitats within this ecosystem. This study will include the identification of all metazoan and foraminiferan meiobenthic species, the description of new species and the characterization of any microbial symbioses that might be found. It will allow us to distinguish communities within the spreading center (between active and inactive sites, either hard substrate, sulfide precipitates, or soft sediments) and the off axis ridge areas. From these descriptive data, underlying evolutionary and historical processes may be invoked and hypothesis on the origin and evolution of vent meiobenthos can be developed. These data will also enable the estimating of meiobenthic biodiversity and biomass, to distinguish and characterize the meiobenthic communities and to estimate their ecological impact by integrating these data into a broader framework of biological and geochemical studies that are carried out in parallel. Within this framework, the proposed work will greatly increase the understanding of the entire hydrothermal vent community and of interactions therein.