HR: 1340h
AN: B13A-0193    [Abstracts]
TI: RIDGE 2000 Integrated Studies: Patterns of Hydrothermal Ecosystem Variation Within Lau Basin
AU: * Shank, T M
EM: tshank@whoi.edu
AF: Biology Department, MS33 Redfield, Woods Hole, MA 02543 United States
AU: Yoerger, D R
EM: dyoerger@whoi.edu
AF: Applied Ocean Physics & Engineering Department, MS7 Blake, Woods Hole, MA 02543 United States
AU: Bradley, A
EM: abradley@whoi.edu
AF: Applied Ocean Physics & Engineering Department, MS7 Blake, Woods Hole, MA 02543 United States
AU: Fornari, D J
EM: dfornari@whoi.edu
AF: Geology and Geophysics Department, MS24 Clark, Woods Hole, MA 02543 United States
AB: The Lau Basin represents a contrast to other mid-ocean ridge systems because of its relative youth (<6 Ma), unique autotrophic ecology of (often gastropod-dominated) ecosystems, and potential for heterogeneous geochemical habitats. These settings provide fertile ground for numerous alternative hypotheses to understand larval transport, species interactions, community structure and succession, endemism, faunal speciation, and biogeographic convergences. These hypotheses require knowledge of the relational distribution of actively venting sites (for larval transport, gene flow, evolution), and individual communities/species (regional species pool for community succession and species interaction), and in some cases geochemical conditions and circulation patterns. While Lau Basin fauna have been taxonomically assessed and trophic (i.e., symbiotic) character of the dominant species revealed virtually nothing is known about the ecological settings and distribution of communities within the Basin - information critical to initiate detailed and efficient biological studies. Western Pacific sites like Manus, North Fiji, and Lau share some taxonomic similarities at specific, genetic and familial levels, but it is known that each site also supports what so far appear to be endemic species with dynamic evolutionary histories. In September 2004, we characterized patterns of species occurrence among Lau Basin vent sites via digital imaging and mosaic mapping using the Autonomous Benthic Explorer (ABE) AUV and the WHOI TOWCAM imaging system. These data were used to create microhabitat maps and quantitatively assess the distribution, abundance, spatial relationships, and variation in microhabitat structure of both sessile and mobile fauna, and to relate them to hydrothermal activity and geological features. Our studies provide a detailed photo-characterization of constituent communities to elucidate the distribution of venting activity, faunal habitats, and provide a comparison to other Western Pacific back-arc basins for future RIDGE 2000 integrated studies.
DE: 4804 Benthic processes/benthos
DE: 4815 Ecosystems, structure and dynamics
DE: 4832 Hydrothermal systems
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting