HR: 14:25h
AN: C33B-04 INVITED    [Abstracts]
TI: Ecological Investigations of the Subglacial Biome: Challenges and Potential
AU: * Mikucki, J A
EM: jmikucki@fas.harvard.edu
AF: Department of Earth and Planetary Sciences, 20 Oxford Street Harvard University, Cambridge, MA 02138, United States
AB: More than 80% of the Earth's biosphere is cold (<4°C) and over 10% of the Earth's surface is covered by ice. Cold icy environments are now known to support a surprising diversity of active microbial life. This talk will provide a brief background on the current understanding of life in icy environments and discuss methods being used by the subglacial community for life detection and in situ measurements as well as a "wish list" of desired biogeochemical observations. Despite new discoveries, there are considerable challenges to the exploration of icy environments. Research on subglacial ecosystems offer significant potential for insight into natural systems; they provide a unique "model" to study microbial communities in relative geological isolation. The long time-scale of entrapment relative to average lifetimes of a microbial cell provides an opportunity to explore questions ranging from the linkages between metabolic pathways, thermodynamics and substrate availability; to the potential for insight about fundamental rates of evolution and constraints on biodiversity. The subglacial environment is one of the most difficult portions of the cryosphere to access and only recently, in collaboration with large-scale drilling projects, are ecologists and biogeochemists beginning to explore the more remote reaches of the subglacial biome. The small sample sizes often retrieved from cold systems, which contain low cell densities and low metabolic activity, present significant challenges to measurements of phylogenetic and metabolic diversity and rates of metabolic activity. While the physical nature of most frozen environments makes in situ observations of the interaction between the natural biological assemblage and the surrounding ecosystem difficult at best. There is a growing urgency to understand the role of icy environments in the global system as well as a steady interest in exobiology, thus life detection in cold environments will continue to be an important scientific and engineering challenge with the potential for high reward.
DE: 0410 Biodiversity
DE: 0456 Life in extreme environments
DE: 0716 Cryobiology (0475)
DE: 0793 Biogeochemistry (0412, 0414, 1615, 4805, 4912)
SC: Cryosphere [C]
MN: 2007 Fall Meeting