Pesticide, polycyclic aromatic hydrocarbon and metal contamination in the Fitzroy Estuary, Queensland, Australia

This publication describes results of the project funded by Coastal CRC which studied the presence of apro-industrial contaminants (i.e. pesticides, polycyclic aromatic hydrocarbons (PAHs) and metals) in the Fitzroy Estuary, Central Queensland. Significant concentrations of several herbicides (particularly Atrazine,Tebuthiuron, Diuron) and lower concentrations of several others were confirmed entering the estuary in flood flows from the basin. For atrazine, few concentrations detected exceeded the trigger value for protection of 99% of freshwater species, while for tebuthiuron all detections exceeded this value. Future monitoring should include further evaluation of these residues and their impacts on coastal and marine flora. PAHs concentrations in sediments from the Fitzroy Estuary were low and appeared to be predominantly of natural origin. For metals, levels of Nickel, Chromium and Antimony in sediments exceeded trigger values in several instances. Regression models for the ten metals regulated by ANZECC (2000) showed that levels of Antimony, Silver, Nickel and Mercury were enhanced in several samples, suggesting some historical accumulation. While geological sources for Nickel and Chromium in the Central Queensland region are known, the sources and potential impact on the ecosystem of the other elements warrant investigation and inclusion in a monitoring program.