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Species-specific variations in the nutritional quality of southern ocean phytoplankton in response to elevated pCO2


Wynn-Edwards, C and King, R and Davidson, A and Wright, SW and Nichols, PD and Wotherspoon, SJ and Kawaguchi, S and Virtue, P, Species-specific variations in the nutritional quality of southern ocean phytoplankton in response to elevated pCO2, Water (Switzerland), 6, (6) pp. 1840-1859. ISSN 2073-4441 (2014) [Refereed Article]


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Licensed under Creative Commons Attribution 3.0 Unported (CC BY 3.0)

DOI: doi:10.3390/w6061840


Increased seawater pCO2 has the potential to alter phytoplankton biochemistry, which in turn may negatively affect the nutritional quality of phytoplankton as food for grazers. Our aim was to identify how Antarctic phytoplankton, Pyramimonas gelidicola, Phaeocystis antarctica, and Gymnodinium sp., respond to increased pCO2. Cultures were maintained in a continuous culture setup to ensure stable CO2 concentrations. Cells were subjected to a range of pCO2 from ambient to 993 μatm. We measured phytoplankton response in terms of cell size, cellular carbohydrate content, and elemental, pigment and fatty acid composition and content. We observed few changes in phytoplankton biochemistry with increasing CO2 concentration which were species-specific and predominantly included differences in the fatty acid composition. The C:N ratio was unaffected by CO2 concentration in the three species, while carbohydrate content decreased in Pyramimonas gelidicola, but increased in Phaeocystis antarctica. We found a significant reduction in the content of nutritionally important polyunsaturated fatty acids in Pyramimonas gelidicola cultures under high CO2 treatment, while cellular levels of the polyunsaturated fatty acid 20:5ω3, EPA, in Gymnodinium sp. increased. These changes in fatty acid profile could affect the nutritional quality of phytoplankton as food for grazers, however, further research is needed to identify the mechanisms for the observed species-specific changes and to improve our ability to extrapolate laboratory-based experiments on individual species to natural communities. © 2014 by the authors.

Item Details

Item Type:Refereed Article
Keywords:Southern Ocean Phytoplankton, seawater pCO2, phytoplankton biochemistry
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Biological oceanography
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Understanding climate change
Objective Field:Effects of climate change on Antarctic and sub-Antarctic environments (excl. social impacts)
UTAS Author:Wynn-Edwards, C (Dr Cathryn Wynn-Edwards)
UTAS Author:Davidson, A (Dr Andrew Davidson)
UTAS Author:Wright, SW (Dr Simon Wright)
UTAS Author:Nichols, PD (Dr Peter Nichols)
UTAS Author:Wotherspoon, SJ (Dr Simon Wotherspoon)
UTAS Author:Kawaguchi, S (Dr So Kawaguchi)
UTAS Author:Virtue, P (Associate Professor Patti Virtue)
ID Code:94448
Year Published:2014
Web of Science® Times Cited:22
Deposited By:CRC-Antarctic Climate & Ecosystems
Deposited On:2014-09-09
Last Modified:2017-11-01
Downloads:389 View Download Statistics

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