HR: 0800h
AN: B21A-1016    [Abstracts]
TI: Archaeal Diversity Associated with Deep Sea Whalefalls
AU: * Wilpiszeski, R
EM: reginaw@its.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Mail Code 100-23, Pasadena, CA 91125 United States
AU: Goffredi, S
EM: goffredi@caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Mail Code 100-23, Pasadena, CA 91125 United States
AU: Turk, K
EM: kat@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Mail Code 100-23, Pasadena, CA 91125 United States
AU: Vrijenhoek, R
EM: vrijen@mbari.org
AF: Monterey Bay Aquarium Research Institute, 7700 Sandholdt Road, Moss Landing, CA 95039 United States
AU: House, C H
EM: chouse@geosc.psu.edu
AF: Dept. Geosciences, Penn State University, 503 Deike Building, University Park, PA 16802 United States
AU: Orphan, V
EM: vorphan@gps.caltech.edu
AF: Division of Geological and Planetary Sciences, California Institute of Technology, Mail Code 100-23, Pasadena, CA 91125 United States
AB: Deep sea whale fall sites support a diverse population of organisms in an otherwise sparsely populated environment. While the macro- and megafauna of these ecosystems have been investigated in some detail, less is known about the nature of associated microbial populations. 16S rRNA gene surveys were used to evaluate the diversity of Archaea in the sediment below one such whale fall at 2800 m water depth and at a nearby control site. A variety of Archaea were identified, including diverse uncultured marine crenarchaeota, phylotypes related to hydrogenotrophic methanogens (Methanogenium spp.), and methylotrophic methanogens associated with the Methanococcoides. No methanogens were discovered at the control site, while hydrogenotrophic methanogens accounted for approximately 20% of the samples from surface sediments below the whale and 35% of the Archaea identified from 12.5 to 15 cm below the whale; the single methylotrophic methanogen was identified within the 12.5 to 15 cm depth sample. The presence of methanogenic phylotypes associated with the whale fall corroborates geochemical observations of elevated methane concentrations observed in the shallow sediments directly beneath the whale fall. This combined geochemical and microbiological evidence suggests that near surface organic matter remineralization is occurring via a methanogenic pathway within this deep sea whale fall habitat rather than the typical sulfidogenic dominated diagenesis commonly observed at other whale fall locations and within shallow marine sediments worldwide.
DE: 4840 Microbiology and microbial ecology (0465)
SC: Biogeosciences [B]
MN: Fall Meeting 2005