A blue-ice ecosystem on the margins of the East Antarctic ice sheet
Freezing temperatures, desiccation and high levels of solar radiation make the surface ofthe Antarctic ice sheet one of Earth's harshest habitats. However, our study in the Vestfold Hills area ofEast Antarctica shows that favourable conditions for microbial production become established justben...
| Published in: | Journal of Glaciology |
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| Main Authors: | , , , , |
| Format: | Article in Journal/Newspaper |
| Language: | English |
| Published: |
Int Glaciol Soc
2013
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| Subjects: | |
| Online Access: | https://doi.org/10.3189/2013JoG12J052 http://ecite.utas.edu.au/89529 |
| Summary: | Freezing temperatures, desiccation and high levels of solar radiation make the surface ofthe Antarctic ice sheet one of Earth's harshest habitats. However, our study in the Vestfold Hills area ofEast Antarctica shows that favourable conditions for microbial production become established justbeneath the surface of blue-ice areas, which collectively cover about 2% of the ice-sheet periphery.Their translucent, wind-polished surface allows solar heating to create meltwater in a greenhouse-typeenvironment at depths of up to 1m. Melting is intensified around dark debris particles, or cryoconite,where we found microbiological activity to be greatest. Rates of photosynthesis (average 2060 ngC(g cryoconite)-1 d-1) were adapted to low light intensities (~10% of surface irradiance values) and mostlikely dominated by cyanobacteria and Chloroplastida. A heterotrophic bacterial community was alsofound to be active within the cryoconite, although average bacterial growth rates (5.7 ngC(g cryoconite)-1 d-1) were far lower than average community respiration (1870 ng C(g cryoconite)-1 d-1). Themajority of the respired carbon was most likely associated with the autotrophs and several protists.Therefore, blue-ice areas constitute oases for microbial life around the periphery of Earth's coldestice sheet. |
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