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Recent environmental change and trace metal pollution in World Heritage Bathurst Harbour, southwest Tasmania, Australia

Saunders, Krystyna ; Harrison, Jennifer ; Butler, Edward ; Hodgson, Dominic ; McMinn, Andrew

In: Journal of Paleolimnology, 2013, vol. 50, no. 4, p. 471-485

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    Titre
    • Recent environmental change and trace metal pollution in World Heritage Bathurst Harbour, southwest Tasmania, Australia
    Auteur
    • Saunders, Krystyna. Institute of Geography and the Oeschger Centre for Climate Change Research, University of Bern, 3012, Bern, Switzerland
    • Harrison, Jennifer. Australian Nuclear Science and Technology Organisation, 2234, Lucas Heights, NSW, Australia
    • Butler, Edward. Australian Institute of Marine Science, 0811, Casuarina, NT, Australia
    • Hodgson, Dominic. British Antarctic Survey, Natural Environment Research Council, CB3 0ET, Cambridge, UK
    • McMinn, Andrew. Institute for Marine and Antarctic Studies, University of Tasmania, 7000, Hobart, TAS, Australia
    Type de document
    • Postprint
    Langue
    • Anglais
    Publié dans
    • Journal of Paleolimnology, 2013, vol. 50, no. 4, p. 471-485. Springer Netherlands
    Autre version électronique
    Identifiant OAI-PMH
    • oai:doc.rero.ch:317773
    Summary
    Bathurst Harbour in World Heritage southwest Tasmania, Australia, is one of the world's most pristine estuarine systems. At present there is a lack of data on pollution impacts or long-term natural variability in the harbor. A ca. 350-year-old 210Pb-dated sediment core was analysed for trace metals to track pollution impacts from local and long-range sources. Lead and antimony increased from AD 1870 onwards, which likely reflects remote (i.e. mainland Australian and global) atmospheric pollution sources. Variability in the concentrations of copper and zinc closely followed the history of mining activities in western Tasmania, which began in the AD 1880s. Tin was generally low throughout the core, except for a large peak in AD 1989±0.5years, which may be a consequence of input from a local small-scale alluvial tin mine. Changes in diatom assemblages were also investigated. The diatom flora was composed mostly of planktonic freshwater and benthic brackish-marine species, consistent with stratified estuarine conditions. Since mining began, however, an overall decrease in the proportion of planktonic to benthic taxa occurred, with the exception of two distinct peaks in the twentieth century that coincided with periods of high rainfall. Despite the region's remoteness, trace metal analyses revealed evidence of atmospheric pollution from Tasmanian and possibly longer-range mining activities. This, together with recent low rainfall, appears to have contributed to altering the diatom assemblages in one of the most pristine temperate estuaries in the world