title: The impact of a high magnitude flood on metal pollution in a shallow subtropical estuarine embayment.
abstract: Drought-breaking floods pose a risk to coastal water quality as sediments, nutrients, and pollutants stored within catchments during periods of low flow are mobilized and delivered to coastal waters within a short period of time. Here we use subtidal surface sediment surveys and sediment cores to explore the effects of the 2011 Brisbane River flood on trace metals zinc (Zn), lead (Pb), copper (Cu), nickel (Ni), chromium (Cr), manganese (Mn), and phosphorus (P) deposition in Moreton Bay, a shallow subtropical bay in eastern Australia. Concentrations of Zn, Cu, and Pb in sediments in central Moreton Bay derived from the 2011 flood were the highest yet observed in the Bay. We suggest flushing of metal rich sediments which had accumulated on the Brisbane River floodplain and in its estuary during the preceding 10 to 40years of low flows to be the primary source of this increase. This highlights the importance of intermittent high magnitude floods in tidally influenced rivers in controlling metal transport to coastal waters in subtropical regions.
authors.affiliation: Australian Rivers Institute, Griffith University, Nathan, QLD 4103, Australia. Electronic address: jack.coatesmarnane@griffithuni.edu.au.
authors.forename: J
authors.initials: J
authors.lastname: Coates-Marnane
authors.affiliation: Australian Rivers Institute, Griffith University, Nathan, QLD 4103, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Olley
authors.affiliation: Chemistry Centre, Department of Science, Information Technology, and Innovation, Dutton Park, QLD 4102, Australia.
authors.forename: J
authors.initials: J
authors.lastname: Burton
authors.affiliation: School of Civil Engineering, The University of Queensland, St Lucia, QLD 4072, Australia.
authors.forename: A
authors.initials: A
authors.lastname: Grinham
mesh_terms: D000535:Aluminum / Q000032:analysis*; D061006:Bays / Q000032:analysis*; D004784:Environmental Monitoring; D055868:Floods; D019015:Geologic Sediments / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis*; D011793:Queensland; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical; D000535:Aluminum
keywords: Estuarine embayment; Estuarine processes; Flooding; Sediment transport; Subtropics; Trace metals