Seagrass soil archives reveal centennial-scale metal smelter contamination while acting as natural filters

• Published in: Science of The Total Environment
• Main Authors: Lafratta, A., Serrano, Oscar, Masqué, Pere, Mateo, Miguel Ángel, Fernandes, M., Gaylard, S., Lavery, Paul S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2019
• Subjects: Heavy metals; Lead isotopes; South Australia; Seagrass soil deposits; Holocene; Southern Ocean; Edith
• Online Access: http://hdl.handle.net/10261/178112

Este artículo contiene 12 páginas, 7 figuras, 1 tabla. The upper Spencer Gulf in South Australia hosts the world's largest single stream Pb-Zn smelter, which has caused environmental and health issues related to elevated metal concentrations in the surrounding environment. The area also has extensive seagrass meadows, occupying N4000 km2 . We reconstructed the fluxes of heavy metals over the last ~3000 years through a multi-parameter study of the soil archives formed by the seagrass Posidonia australis. Pb, Zn and Cd concentrations increased up to 9-fold following the onset of smelter operations in the 1880s, and the stable Pb isotopic signatures confirmed the smelter has been the main source of lead pollution in the seagrass soils until present. Preliminary estimates suggest that over the past 15 years seagrass meadows within 70 km2 of the smelter accumulated ~7–15% of the smelter emissions in their soils. Here we demonstrate that seagrass meadows act as pollution filters and sinks while their soils provide a record of environmental conditions, allowing baseline conditions to be identified and revealing the time-course of environmental change. This research was funded through by Edith Cowan University (ECU), the Environmental Protection Authority of South Australia and South Australia Water Corporation, through an ECU-Industry grant (G1001729). For part of the project OS was supported by an ARC DECRA (DE170101524), AL by Holsworth Wildlife Research Endowment – Equity Trustees Charitable Foundation and PM by the Australian Research Council (LE170100219). Peer reviewed