Microalgae growing within brine channels (85 psu salinity) of the surface ice layers of Antarctic pack ice showed considerable photosynthetic tolerance to the extreme environmental condition. Brine microalgae exposed to temperatures above -5°C and at irradiances up to 350 μmol photons· m -2·s-1 showed no photosynthetic damage or limitations. Photosynthesis was limited (but not photoinhibited) when brine microalgae were exposed to -10°C, provided the irradiance remained under 50 μmol photons·m-2·s-1. The highest level of photosynthetic activity (maximum relative electron transport rate [rETR max]) in brine microalgae growing within the surface layer of sea ice was at approximately 18 μmol electrons·m-2·s -1, which occurred at -1.8° C. Effective quantum yield of PSII and rETRmax of the halotolerant brine microalgae exhibited a temperature-dependent pattern, where both parameters were higher at -1.8° C and lower at -10° C. Relative ETRmax at temperatures above -5°C were stable across a wide range of irradiance. © 2005 Phycological Society of America.

Item Type:	Refereed Article
Research Division:	Biological Sciences
Research Group:	Ecology
Research Field:	Marine and estuarine ecology (incl. marine ichthyology)
Objective Division:	Environmental Management
Objective Group:	Terrestrial systems and management
Objective Field:	Assessment and management of terrestrial ecosystems
UTAS Author:	McMinn, A (Professor Andrew McMinn)
UTAS Author:	Ashworth, CM (Mr Chris Ashworth)
ID Code:	38123
Year Published:	2005
Funding Support:	Australian Research Council (DP0344067)
Web of Science® Times Cited:	58
Deposited By:	IASOS
Deposited On:	2005-08-01
Last Modified:	2006-05-09
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