Freezing temperatures, desiccation and high levels of solar radiation make the surface of the Antarctic ice sheet one of Earth's harshest habitats. However, our study in the Vestfold Hills area of East Antarctica shows that favourable conditions for microbial production become established just beneath 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-type environment 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 most likely dominated by cyanobacteria and Chloroplastida. A heterotrophic bacterial community was also found 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). The majority 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 coldest ice sheet.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Microbiology
Research Field:	Microbial ecology
Objective Division:	Environmental Management
Objective Group:	Management of Antarctic and Southern Ocean environments
Objective Field:	Antarctic and Southern Ocean oceanic processes
UTAS Author:	Paterson, H (Dr Harriet Paterson)
UTAS Author:	Westwood, K ( Westwood)
ID Code:	89529
Year Published:	2013
Web of Science® Times Cited:	24
Deposited By:	IMAS Research and Education Centre
Deposited On:	2014-03-06
Last Modified:	2022-08-31
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