The impacts of intensive mining on terrestrial and aquatic ecosystems: a case study from cool temperate Tasmania, Australia
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Date
2019-07-30
Journal Title
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Publisher
International Union for Quaternary Research (INQUA)
Abstract
Mining has caused extensive damage to aquatic systems worldwide with acidification, heavy metal pollution, increased sediment loading and Ca decline of freshwaters. While some aquatic ecosystems are thought to be recovering from past mining, a long-term context is needed to determine if pre-impact conditions have been restored. Here we explore the palaeoenvironmental history of Owen Tarn, western Tasmania, to assess the impacts of mining from Mt. Lyell on aquatic ecosystems. Analysis of a new sediment core using radiometric dating, sediment geochemistry, pollen, and diatoms are used to examine the full extent of mining and heavy metal pollution on aquatic and terrestrial ecosystems pre- and post-mining in this region. Our analysis indicates four key phases of environmental change: (1) A pre-mining phase (550-1160 CE); (2) an early impact phase (British invasion) shows land clearance and vegetation removal by burning during mineral exploration; (3) an intense mining period (1950 CE) had severe negative impact on the diatom community in which sediment pollution from a lack of vegetation and heavy erosion, rather than acidification, was the main driver of change; and (4) a post-mining phase (2006 CE) in which vegetation on the landscape began to recover and aquatic productivity increased. Despite this apparent recovery of the system, the aquatic community continues to experience impacts from mining. The diatom community has not returned to its pre-impact state, but rather there is evidence of a secondary impact from declining Ca in the system. The relevance of these findings demonstrates the importance of well dated palaeoecological records to inform management and mitigate human impacts on the environment.
Description
Keywords
Mining, Aquatic ecosystems, Tasmania, Fresh water, Australia, Environment, Vegetation, Pollen, Geochemistry, Humans
Citation
Beck. L., Mariani, M., Fletcher, M.-S., Gadd, P., Heijnis, H., Saunders, K., & Zawadzki, A. (2019). The impacts of intensive mining on terrestrial and aquatic ecosystems: a case study from cool temperate Tasmania, Australia. Poster presented to the 20th INQUA Congress 25th - 31st July 2019, Dublin, Ireland. Retrieved from: https://virtual.oxfordabstracts.com/#/event/public/574/submission/1772