HR: 1340h
AN: B13A-0216    [Abstracts]
TI: Microbial Colonization of Mineral Substrates on Loihi Seamount
AU: * Banning, E C
EM: ebanning@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Biology, McLean Lab, MS #8, Woods Hole, MA 02543 United States
AU: Rogers, D
EM: drogers@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Marine Chemistry and Geochemistry, McLean Lab, MS #8, Woods Hole, MA 02543 United States
AU: Edwards, K J
EM: katrina@whoi.edu
AF: Woods Hole Oceanographic Institution, Department of Marine Chemistry and Geochemistry, McLean Lab, MS #8, Woods Hole, MA 02543 United States
AB: Seafloor weathering involves the biologically influenced alteration of basaltic rocks during reaction with seawater. The dynamics of this process have implications for global climate by removing carbon dioxide from seawater and ocean chemistry via elemental exchange during weathering. Additionally, seafloor weathering communities may represent a significant fraction of the subsurface biosphere. To understand the ecology and geochemistry of seafloor weathering, it is important to understand the population dynamics and activities of the microbiological populations colonizing rock surfaces on the seafloor during weathering. Various naturally occurring substrates common to the seafloor (including basalt and pyrite) were incubated in situ for one year on the seafloor at different distances from hydrothermal vents on the Loihi seamount, the newest basaltic shield volcano in the Hawaiian arc. Before placement on the seafloor, the mineral samples were sterilized, well-characterized and mounted on slides. The slides were collected in sample baskets which were then delivered to the seafloor via submersible in December 2002 and retrieved in December 2003. We are using DAPI staining and fluorescent in-situ hybridizations (FISH) to characterize the microbial populations which colonizing these substrates. FISH is performed with domain-specific oligonucleotide probes (for bacteria [eub338] and archaea [arch915]) to determine the relative proportions of the two domains in the colonizing communities, as well as to assess total cell numbers, as functions of both substrate and conditions in situ. Our observations indicate that both mineralogy and local chemical/physical conditions significantly influence colonization and weathering of the substrates reacted.
DE: 4832 Hydrothermal systems
DE: 4840 Microbiology
DE: 4803 Bacteria
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting