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Summer–winter transitions in Antarctic ponds: III. Chemical changes

Published online by Cambridge University Press:  25 October 2011

Jenny Webster-Brown ,
Ian Hawes ,
Karl Safi ,
Brian Sorrell  and
Nathaniel Wilson
Jenny Webster-Brown*
Affiliation:
University of Canterbury, Private Bag 4800, Christchurch, New Zealand
Ian Hawes
Affiliation:
University of Canterbury, Private Bag 4800, Christchurch, New Zealand
Karl Safi
Affiliation:
NIWA Ltd, PO Box 11-115, Hamilton, New Zealand
Brian Sorrell
Affiliation:
Dept Biological Sciences, Aarhus University, 8000 Aarhus 3, Denmark
Nathaniel Wilson
Affiliation:
University of Bayreuth, Bayreuth, Germany
*
[email protected]
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Abstract

Observations were made of water column chemistry in four Na-Cl dominated ponds on the McMurdo Ice Shelf from the end of January to early April in 2008. During that time the ponds went from ice-free to predominantly frozen, with only a small volume of residual hypoxic, saline liquid trapped at the base of each pond. Changes in the concentrations of inorganic solutes with time distinguished Na, Cl, Mg, K, SO4, As, U and Mn as ions and trace elements that behave mainly conservatively during freezing, from those which are affected by biological processes (removing HCO3) and the precipitation of mineral phases such as calcite (removing Ca and more HCO3). Dissolved Fe, Mo, Cu and Zn also show evidence of precipitation from the water column during freezing; geochemical speciation modelling predicts the formation of stable insoluble mineral phases such as Fe oxides and oxyhydroxides while conditions are oxic, and Fe-, Cu-, Mo- and Zn-sulphide minerals in the presence of H2S. Consequently, under winter conditions, residual liquid beneath the ice in such ponds is anticipated to be an anoxic Na-Cl brine with the capacity to develop high concentrations of toxic trace elements such as As and U.

Keywords

freeze concentrationmajor ionMcMurdo Ice ShelfPHREEQC modellingtrace element
Type
Biological Sciences
Information
Antarctic Science , Volume 24 , Issue 2 , 28 February 2012 , pp. 121 - 130
Copyright
Copyright © Antarctic Science Ltd 2011

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References

APHA. 1999. Standard methods for the examination of water and wastewater, 20th ed. Washington, DC: American Public Health Association, 1325 pp.Google Scholar
Dzombak, D.A.Morel, F.M.M. 1990. Surface complexation modelling - hydrous ferric oxide. London: Wiley Interscience, 393 pp.Google Scholar
Green, W.J., Canfield, D.E., Shengsong, Y., Chave, K.E., Ferdelman, T.G.Delanois, G. 1993. Metal transport and release processes in Lake Vanda: the role of oxide phases. Antarctic Research Series, 59, 145–163.Google Scholar
Hawes, I., Schwarz, A.-M., Smith, R.Howard-Williams, C. 1999. Environmental conditions during freezing, and response of microbial mats in ponds of the McMurdo Ice Shelf, Antarctica. Antarctic Science, 11, 198–208.CrossRefGoogle Scholar
Hawes, I., Safi, K., Webster-Brown, J., Sorrell, B.Arscott, D. 2010a. Summer–winter transitions in Antarctic ponds I: the physical environment. Antarctic Science, 23, 235–242.CrossRefGoogle Scholar
Hawes, I., Safi, K., Webster-Brown, J., Sorrell, B.Arscott, D. 2010b. Summer–winter transitions in Antarctic ponds II: biological responses. Antarctic Science, 23, 243–254.CrossRefGoogle Scholar
Healy, M., Webster-Brown, J.G., Brown, K.L.Lane, V. 2006. Chemistry and stratification of Antarctic meltwater ponds II: inland ponds in the McMurdo Dry Valleys, Victoria Land. Antarctic Science, 18, 525–533.Google Scholar
Howard-Williams, C.Hawes, I. 2007. Ecological processes in Antarctic inland waters: interactions between physical processes and the nitrogen cycle. Antarctic Science, 19, 205–217.CrossRefGoogle Scholar
Parkhurst, D.L.Appelo, C.A.J. 1999. PHREEQC (ver. 2) - a computer program for speciation, batch-reaction, one-dimensional transport, and inverse geochemical calculations. USGS Water Resources Investigations Report, No. 994259.Google Scholar
Schmidt, S.W., Moskal, W., De Mora, S.J., Howard-Williams, C.Vincent, W.F. 1991. Limnological properties of Antarctic ponds during winter freezing. Antarctic Science, 3, 379–388.CrossRefGoogle Scholar
Vincent, W.F.James, M.R. 1996. Biodiversity in extreme aquatic environments: lakes, ponds and streams of the Ross Sea sector, Antarctica. Biodiversity and Conservation, 5, 1451–1471.Google Scholar
Wait, B.R., Nokes, R.Webster-Brown, J.G. 2009. Freeze–thaw dynamics and the implications for stratification and brine geochemistry in meltwater ponds on the McMurdo Ice Shelf, Antarctica. Antarctic Science, 21, 243–254.CrossRefGoogle Scholar
Wait, B.R., Webster-Brown, J.G., Brown, K.R., Healy, M.Hawes, I. 2006. Chemistry and stratification of Antarctic meltwater ponds I: coastal ponds near Bratina Island, McMurdo Ice Shelf. Antarctic Science, 18, 515–524.CrossRefGoogle Scholar
Webster, J.G. 1994. Trace metal behaviour in oxic and anoxic Ca-Cl brines of the Wright Valley drainage, Antarctica. Chemical Geology, 112, 255–274.CrossRefGoogle Scholar
Webster, J.G., Brown, K.L.Vincent, W.F. 1994. Chemistry and nutrient content of meltwaters of the Victoria Valley, Antarctica. Hydrobiologia, 281, 171–186.CrossRefGoogle Scholar
Webster, J.G., Webster, K.S.Hawes, I. 1997. Trace metal transport and speciation in Lake Wilson, a comparison with Lake Vanda. In Lyons, B., Howard-Williams, C.&Hawes, I., eds. Ecosystems and processes in Antarctic ice-free landscapes. Rotterdam: Balkema, 221–230.Google Scholar
Webster-Brown, J.G.Webster, K.S. 2007. Trace metals in cyanobacterial mats, phytoplankton and sediments of the Lake Vanda region, Antarctica. Antarctic Science, 19, 311–319.CrossRefGoogle Scholar
Welch, K.A., Lyons, W.B., Graham, E., Neumann, K., Thomas, J.M.Mikesell, D. 1996. Determination of major element chemistry in terrestrial waters from Antarctica by ion chromatography. Journal of Chromatography, A739, 257–263.Google Scholar