An International Plan for Antarctic Subglacial Lake Exploration

Abstract

Discovery of at least 100 subglacial lakes beneath the vast East Antarctic Ice Sheet has focused international attention on the challenges presented by the way we conduct science in such unique and inhospitable settings in an atmosphere of increasingly stringent environmental concerns. Exploration of subglacial environments will require careful and detailed planning, organization, and international cooperation. To this end, the Scientific Committee on Antarctic Research (SCAR) convened an international Group of Specialists (Subglacial Antarctic Lake Exploration Group of Specialists-SALEGOS) to develop a detailed assessment of the needs and critical milestones to be accomplished during the implementation of a subglacial exploration and research program. This paper surveys the progress and recommendations made by SALEGOS since its inception regarding the current state of knowledge of subglacial environments, technological needs and challenges, international management, the portfolio of scientific projects, and "clean" requirements for entry, observatory deployment, and sample retrieval.

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“…Metabolic and culture experiments demonstrated that a portion of the assemblage in the accretion ice is metabolically active when exposed to liquid water and organic electron donors (Karl et al 1999;Christner et al 2001). Molecular identification of microbes within the accretion ice (by culturing and small subunit rRNA gene amplification) show close agreement with present day surface microbiota that classify within the bacterial phyla Proteobacteria (a, b, and c), Firmicutes, Actinobacteria, and Bacteroidetes (Priscu et al 1999;Christner et al 2001;Bulat et al 2004). All of the studies described above focused on a limited number of accretion ice sections, most of which formed in the shallow western embayment, and therefore do not reveal the limnological nature of the system.…”

“…The difference in ice thickness produces a gradient in the pressure freezing point (Kapista et al 1996), which would drive water circulation (Wü est and Carmack 2000; Siegert et al 2003). The surface waters will be at the pressure melting point of 22.5 to 22.8uC (Wü est and Carmack 2000), and total dissolved solids have been predicted to range from ,1 to 40 mmol L 21 (Priscu et al 1999;Siegert et al 2003;Royston-Bishop et al unpubl. data).…”

“…Although these oxygen estimates assume no biogenic alteration within the lake, it has been hypothesized that aerobic conditions in the upper portion of the water column could support autotrophic and heterotrophic metabolic lifestyles, whereas deeper portions of the lake and sediment are likely to be anoxic if biotic and abiotic O 2 sinks exist (Siegert et al 2003). The heterotrophic potential of the lake is supported by measurable dissolved organic carbon concentrations in the accretion ice (Karl et al 1999;Priscu et al 1999), together with microbial respiration of organic substrate in melted ice samples (Karl et al 1999). …”

“…Microbiological and molecular-based studies of the accretion ice have shown low but detectable amounts of prokaryotic cells and deoxyribonucleic acid (DNA; Karl et al 1999;Priscu et al 1999;Christner et al 2001). Metabolic and culture experiments demonstrated that a portion of the assemblage in the accretion ice is metabolically active when exposed to liquid water and organic electron donors (Karl et al 1999;Christner et al 2001).…”

Microbiology: lessons from a first attempt at Lake Ellsworth

“…One of the key goals of Antarctic subglacial lake exploration has been to measure, analyse and understand life in these extreme environments [5]. Microbiological activity and function have already been shown to be present in such systems, albeit at the ice sheet margin [6].…”