HR: 10:20h
AN: OS42A-01    [Abstracts]
TI: Microbial Communities at Non-Volcanic and Volcanic Sites of the Gakkel Ridge
AU: * Helmke, E
EM: ehelmke@awi-bremerhaven.de
AF: Alfred-Wegener-Institute, Am Handelshafen 12, Bremerhaven, 27570, Germany
AU: Juergens, J
EM: jjuergens@awi-bremerhaven.de
AF: Alfred-Wegener-Institute, Am Handelshafen 12, Bremerhaven, 27570, Germany
AU: Tausendfreund, M
EM: Maria.Tausendfreund@awi.de
AF: Alfred-Wegener-Institute, Am Handelshafen 12, Bremerhaven, 27570, Germany
AU: Wollenburg, J
EM: Jutta.Wollenburg@awi.de
AF: Alfred-Wegener-Institute, Am Handelshafen 12, Bremerhaven, 27570, Germany
AU: Shank, T
EM: tshank@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Rd., Woods Hole, MA 02543, United States
AU: Edmonds, H
EM: edmonds@utmsi.utexas.edu
AF: University of Texas at Austin, Marine Science Inst.750 Channel View Drive, Port Aransas, TX 78373-5015, United States
AU: Humphris, S
EM: shumphris@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Rd., Woods Hole, MA 02543, United States
AU: Nakamura, K
EM: koichi.nakamura@aist.go.jp
AF: Advanced Industrial Science and Technology, Marine Geology Department 1-1-13 Higashi, Tsukuba, Ibaraki, 305-8567, Japan
AU: Liljebladh, B
EM: beli@oce.gu.se
AF: Goeteborg University, Dept. Earth Scienc.-Ocean. P.O.Box 460, Goeteborg, SE-40530, Sweden
AU: Winsor, P
EM: pwinsor@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Rd., Woods Hole, MA 02543, United States
AU: Singh, H
EM: hsingh@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Rd., Woods Hole, MA 02543, United States
AU: Reves-Sohn, R A
EM: rsohn@whoi.edu
AF: Woods Hole Oceanographic Institution, 360 Woods Hole Rd., Woods Hole, MA 02543, United States
AB: The Gakkel Ridge in the eastern Arctic Ocean is the slowest spreading, deepest, and most isolated portion of the global mid-ocean ridge system and therefore predestined for comparative investigations on deep-sea vent communities. However, the perennial cover of thick sea ice has made this area largely inaccessible to science. The Arctic Gakkel Vents Expedition (AGAVE) utilized the icebreaker ODEN and newly developed vehicles for exploration and sampling in connection with a CTD/rosette equipped with different sensors and a high-resolution multi-beam bathymetry system. We focused our studies on the peridotite-hosted region at 85°N, 7°E and on the basaltic volcanism area at 85°N, 85°E. Water, sediment, and rock samples were taken to describe the microbial communities in different zones of these two sites. Sampling was guided by anomalies of backscattering, temperature, Eh, as well as by high-resolution seafloor imagery. Samples were preserved or processed on board immediately after sampling. Molecular analyses, cultural methods, total bacterial counts, and activity measurements were employed to describe the structure of the microbial communities, their phylogeny, potential adaptations, and possible role in biogeochemical cycles. The first molecular biological results of the bacterial communities of the 85°E site indicated atypical of deep- sea venting communities. These preliminary results were supported by the images of the under-ice vehicle "Camper" which showed thick yellow "fluffy" mats (often > 5cm thick) and orange "pebbly" material without any smell of H2S markedly different than the white, consolidated Beggiatoa mats often observable at deep venting sites. Foraminifera occurred regularly on top of basalt rocks as well as within the bacterial mats.
DE: 4840 Microbiology and microbial ecology (0465)
SC: Ocean Sciences [OS]
MN: 2007 Fall Meeting