| Autor: |
Amato ED; Centre for Environmental Contaminants Research, CSIRO Land and Water , Locked Bag 2007, Kirrawee, NSW 2232, Australia.; School of Chemistry, University of Wollongong , Wollongong, NSW 2522, Australia., Simpson SL; Centre for Environmental Contaminants Research, CSIRO Land and Water , Locked Bag 2007, Kirrawee, NSW 2232, Australia., Remaili TM; Centre for Environmental Contaminants Research, CSIRO Land and Water , Locked Bag 2007, Kirrawee, NSW 2232, Australia.; School of Chemistry, University of Wollongong , Wollongong, NSW 2522, Australia., Spadaro DA; Centre for Environmental Contaminants Research, CSIRO Land and Water , Locked Bag 2007, Kirrawee, NSW 2232, Australia., Jarolimek CV; Centre for Environmental Contaminants Research, CSIRO Land and Water , Locked Bag 2007, Kirrawee, NSW 2232, Australia., Jolley DF; School of Chemistry, University of Wollongong , Wollongong, NSW 2522, Australia. |
| Abstrakt: |
The burrowing and feeding activities of benthic organisms can alter metal speciation in sediments and affect an organisms' exposure to metals. Recently, the performance of the in situ technique of diffusive gradients in thin films (DGT) for predicting metal bioavailability has been investigated in response to the increasing demand of considering contaminant bioavailability in sediment quality assessments. In this study, we test the ability of the DGT technique for predicting the metal bioavailability in clean and contaminated sediments that are being subjected to varying degrees of sediments disturbance: low bioturbation (bivalve Tellina deltoidalis alone) and high bioturbation (bivalve and actively burrowing amphipod, Victoriopisa australiensis). Significant release of DGT-labile Cd, Ni, Pb, and Zn, but lower Cu and Fe, occurred in the pore and overlying waters of sediments exposed to high bioturbation conditions, resulting in higher bioaccumulation of zinc in bivalves. Strong relationships were found between bioaccumulation of Pb and Zn and time-integrated DGT-metal fluxes, whereas poor relationships were obtained using total or dilute-acid extractable metal concentrations. This results demonstrate that DGT is a useful tool for assessing metal bioavailability in sediments and can provide useful predictions of metal bioavailable to benthic organisms in dynamic sediment environments. |
