Gavin Birch - Academia.edu (original) (raw)
Papers by Gavin Birch
Environment International, 2003
Page 1. 69 Pittock A, 2005. Climate change: turning up the heat , CSIR O Publishing, Collingwood,... more Page 1. 69 Pittock A, 2005. Climate change: turning up the heat , CSIR O Publishing, Collingwood, Victoria. Pindyck RS, 2006. 'Uncertainty in environmental economics', NBER Working Paper 12752 , National Bureau of Economic Research, Cambridge, M assachusetts. ...
Marine Pollution Bulletin, 2003
Concentrations of dissolved metals (Cd, Cu, Ni, Mn and Zn) were determined for summer and winter,... more Concentrations of dissolved metals (Cd, Cu, Ni, Mn and Zn) were determined for summer and winter, under low-flow conditions in Port Jackson, a microtidal, well-mixed estuary in southeast Australia. Mean concentrations of Cd (0.04 AE 0.02 lg/l), Ni (0.86 AE 0.40 lg/l), Mn (20.0 AE 25 lg/l) and Zn (6.47 AE 2.0 lg/l) were below water quality guidelines. Concentrations of Cu (1.68 AE 0.37 lg/l), however, slightly exceeded recommended values. Dissolved Ni and Mn behaved mostly conservatively, whereas Cd, Cu and Zn showed mid-estuarine maxima. Peaks in Cd, Cu and Zn concentrations were located in the upper estuary, independent of the salinity and suspended particulate matter loading, and were consistent with anthropogenic inputs of metals in the estuary. Concentrations of dissolved Cu were highest in summer, whereas concentrations of Cd, Ni and Mn were significantly lower in summer than winter (P 6 0:05). The increase in temperature and biological activity during summer explained the seasonal variation. The sequence of log K d values (20-30 salinity) was Mn > Zn > Cu > Ni. These results give unique information concerning the contemporaneous distribution of dissolved trace metals in the Port Jackson estuary and they provide a data set against which the long-term contamination may be assessed.
Science of The Total Environment, Nov 1, 2023
93rd American Meteorological Society Annual Meeting, Jan 7, 2013
Treatise on Geomorphology
Normalised-metal data provide key information regarding the “health“ of an estuarine system, for ... more Normalised-metal data provide key information regarding the “health“ of an estuarine system, for example, the pristine condition, the magnitude of human-induced change, history of anthropogenic influence, future trends, and time required to reach managerial targets in sediment quality. Total-sediment metal concentrations are used to assess increasing risk to sediment quality, i.e., the ability to support a healthy benthos. Sedimentary metals provide an inexpensive and easily acquired means of making an initial assessment of estuarine health and provide the framework for more detailed and expensive investigations. Sediments should be included in a batch of indicators in estuarine evaluation where key indicators are assessed in a weight-of-evidence matrix.
Piantadosi, J., Anderssen, R.S. and Boland J. (eds) MODSIM2013, 20th International Congress on Modelling and Simulation, 2013
The Sydney estuary (Port Jackson) is a highly modified waterway in which surficial sediments are ... more The Sydney estuary (Port Jackson) is a highly modified waterway in which surficial sediments are extensively contaminated by a suite of chemicals including trace metals. These surficial sediments undergo resuspension into the water column on a daily basis due to both natural and anthropogenic processes which includes tides, currents, bioturbation, shipping, and dredging. As a result, sediment resuspension significantly increases the risk of trace metal contaminant exposure to marine biota. The status of trace metal contamination in surficial sediments, suspended particulate matter, and aquatic organisms has been studied in detail, and in all three media high concentrations have been detected, particularly for Cu, Pb, and Zn. However, a significant relationship linking these processes together has yet to be made and the effect that sediment-bound trace metals inflict on local fauna has not been documented previously. The current study aims to identify the processes controlling bioaccumulation of trace metal contaminants in Sydney estuary using laboratory-based mesocosm experiments. The native Sydney rock oyster (Saccostrea glomerata) was used as a bioindicator species and was exposed to contaminated suspended sediment at a range of controlled concentrations and loads to mimic previously observed field conditions. The oysters were analysed for total bioaccumulated tissue metal concentrations, as well as changes in protein expression to identify probable early-onset bioindicators. The results from the laboratory experiments will be used to parameterise a biogeochemical model to help explain the different mechanisms of trace metal bioaccumulation in Sydney estuary.
Marine Phosphorites, 1980
Page 1. SEPM SPECIAL PUBLICATION No 29 P 79 100 NOVEMBER 1980 A MODEL OF PENECONTEMPORANEOUS PHOS... more Page 1. SEPM SPECIAL PUBLICATION No 29 P 79 100 NOVEMBER 1980 A MODEL OF PENECONTEMPORANEOUS PHOSPHATIZATION BY DIAGENETIC AND AUTHIGENIC MECHANISMS FROM THE WESTERN MARGIN OF SOUTHERN AFRICA ...
effect on floods and droughts in Australia', Climatic change, vol. 25, pp. 289–317. Wilby R L... more effect on floods and droughts in Australia', Climatic change, vol. 25, pp. 289–317. Wilby R L, 2005. 'Uncertainty in water resource model parameters used for climate change impact assessment', Hydrological Processes, vol. 19, pp. 3201–3219. Young P, 2003. 'Top-down and data-based mechanistic modelling of rainfall-flow dynamics at the catchment scale', Hydrological Processes, vol. 17, pp. 2195–2217. Young W, Brandis K & Kingsford R, 2006. 'Modelling monthly streamflows in two Australian dryland rivers: matching model complexity to spatial scale and data availability', Journal of Hydrology, vol. 331, pp. 242–256. Zhang L, Dawes W R & Walker G R, 2001. 'Response of mean annual evapotranspiration to vegetation changes a catchment scale', Water Resources Research, vol. 37, pp. 701–708. Zhang L, Walker G R & Fleming M, 2002. 'Surface water balance for recharge estimation', CSIRO publishing, Collingwood, Victoria.
Environmental Science and Pollution Research, 2020
Narrabeen Lagoon is recognized as an Intermittently Closed and Open Lake or Lagoon (ICOLL) and is... more Narrabeen Lagoon is recognized as an Intermittently Closed and Open Lake or Lagoon (ICOLL) and is the largest coastal lagoon (2.2 km 2) in the Sydney metropolitan region. The catchment (53 km 2) supports five major river systems, and land use comprises of 56% residential, 42% parkland and 2% light industry, commercial, hospital and education. An initial screening environmental assessment was undertaken using sedimentary metals to determine the magnitude of anthropogenic change and level of ecological risk posed by these contaminants. Results illustrated an unusual example of an estuary significantly influenced by humaninduced change, but exhibiting minimal ecological risk. This anomaly was due to high anthropogenic metal concentrations in the fine fraction of surficial sediment, which was considerably diluted by abundant metal-poor coarse material resulting in reduced adverse ecological impact for total sediment. Predictive modelling to 2020 suggested that Pb concentrations will decline and Cu and Zn levels will increase slightly. Modelling of river discharge and analyses of fluvial sedimentary metals suggested stormwater derived from the most urbanized catchments and a major roadway combined with poor flushing explained surficial sediment metal distributions in the lagoon.
Treatise on Estuarine and Coastal Science, 2011
A suite of indicators covering biological, chemical, and physical realms is required for effectiv... more A suite of indicators covering biological, chemical, and physical realms is required for effective management and to ensure sustainability of highly sensitive regional assets in the coastal environment. Indicators need to be easily and inexpensively measured, be free of anthropogenic temporal and spatial influence, and have low natural variance. Sediment chemistry provides the pristine condition, the magnitude of anthropogenic change, and the risk of biological stress due to contaminants in the ecosystem. This chapter describes techniques used in the unambiguous assessment of these parameters and provides examples to demonstrate approaches.
Piantadosi, J., Anderssen, R.S. and Boland J. (eds) MODSIM2013, 20th International Congress on Modelling and Simulation, Dec 1, 2013
Sediments in Sydney estuary (Australia) and soils of the catchment are highly enriched in copper ... more Sediments in Sydney estuary (Australia) and soils of the catchment are highly enriched in copper (Cu), lead (Pb) and zinc (Zn) and these metals are accumulating in tissue of estuarine fauna. To reduce contamination levels, especially in the tissue of bivalve filter-feeders, it is necessary to understand the processes linking source, fate and effects of metals in these environments. It was the aim of the current work to identify key mechanisms controlling bioaccumulation in shellfish inhabiting this estuary by combining the results of existing individual models and monitoring data (oyster soft-tissue concentrations) describing various parts of this system into a single source-fate-effects model. Of the existing models, an atmospheric model (TAPM) showed that vehicle emissions were the major contributor of metals to catchment soils while stormwater modelling indicated that the average annual discharge from Sydney estuary catchment ranged 215,300-372,000 ML with associated loadings of 60,400, 30.5, 49.0 and 89.2 tonnes for total suspended solids (TSS), Cu, Pb and Zn, respectively. A verified hydrodynamic model investigated estuarine response to catchment rainfall and showed that freshwater plumes generated during high-rainfall events broke down within the estuary and that minimal (<1%) associated contaminants exited the estuary to the ocean, whereas TSS and pollutants delivered during low-rainfall were deposited close to discharge points and were trapped within the estuary. Oyster (Saccostrea glomerata) tissue was highly enriched in these metals, however there was no significant relationship with bottom sediment metal concentrations. The integrated model used here comprised a process-based framework describing the water and sediment balance coupled to a chemical (Cu) speciation model and an oyster bioaccumulation model. This integrated model is not spatially explicit on the horizontal plan but consists of two vertical components (aqueous layer and sediment). Early results of the source-fate-effects modelling indicate that the increase in dissolved and particulate organic ligands associated with a stormwater event entering the system appears unable to compensate for the concomitant increase in aqueous Cu and that the excess may be associated with dissolved inorganic ligands after the organic complexation sites have been exhausted. Modelling provides evidence that mechanisms driving pollution in the estuary are sensitive to catchment loading rates, which may result in highly variable soft-tissue Cu concentration in oysters.
Marine Pollution Bulletin, 2020
The detection rates of pharmaceuticals (Ps), personal care products (PCPs), current-use pesticide... more The detection rates of pharmaceuticals (Ps), personal care products (PCPs), current-use pesticides (CUPs) and a food additive (FA) in Brisbane River estuary (Queensland), Sydney estuary (New South Wales) and the Yarra River estuary (Melbourne, Victoria
Marine Pollution Bulletin, 2019
The influence of sedimentary metals on the cockle A. trapezia tissue was examined using a strong ... more The influence of sedimentary metals on the cockle A. trapezia tissue was examined using a strong difference in sedimentary metal concentrations in an embayment (Hen and Chicken Bay) highly contaminated in Cu and an adjacent cove (Iron Cove), strongly enriched in Cd, Cu, Pb and Zn within the heavily-urbanised Sydney estuary catchment (Australia). Statistically significant differences were recorded for cockle tissue metal concentrations between the study locations reflecting differences in surficial sediment metal concentrations. Low metal uptake was apparent in A. trapezia tissue, which were considerably less than background sedimentary concentrations and was of low-risk for human consumption. Dissimilar bioconcentration of Cd, Cu, Pb and Zn was apparent in tissue of cockles (A. trapezia), prawns (Metapenaeus bennettae), mussels (Mytilus galloprovincialis) and oysters (Saccostrea glomerata), due possibly to different feeding patterns and biogeochemical conditions in bottom sediments.
Marine and Freshwater Research, 2000
Trace metal (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) concentrations in the fine fraction (<62.5 µm) of... more Trace metal (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) concentrations in the fine fraction (<62.5 µm) of surficial sediments adjacent to the major urban centres of Sydney, Newcastle and Wollongong on the central New South Wales (NSW) continental margin, Australia, are elevated above regional background. The nature of enrichment off these major urban centres is distinct. The fine fractions of sediments adjacent to Newcastle are enriched in Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn, associated with the disposal of dredged harbour spoil in an offshore dumpsite, whereas adjacent to Sydney, enrichment of Cu, Pb and Zn in the fine fraction of sediments results mainly from the disposal of large volumes of sewage effluent. The source and regional dispersion of trace metals on the central-NSW continental margin can only be established from analysis of the fine fraction of the sediment, because total sediment distributions of contaminants are confounded by a highly variable sediment texture. Generally, low ...
Marine and Freshwater Research, 2003
The present study compared the geochemistry of saline and freshwater percolating through columns ... more The present study compared the geochemistry of saline and freshwater percolating through columns containing soils sampled from reclaimed land adjoining Sydney Harbour, Australia. The investigation assessed the flux of contaminants from the soil and, hence, estimated the affect of reclaimed land (using construction waste or dredged sediment) on the adjoining aquatic environment. Leachate samples were collected weekly for 22 weeks and were monitored for pH, Eh (redox potential), electrical conductivity, dissolved oxygen, major elements and heavy metals. In the early stages of the experiment (until approximately Week 12), the concentrations of the major elements in water percolating from the two columns were similar. Differing pseudo-steady-state conditions were reached in the columns after approximately 14 weeks. Sodium and Cl are weakly sorbed onto surface sites of the material in the saline column. The exchange of Na with other cations results in an increase in the aqueous concentra...
Marine and Freshwater Research, 2003
Major ion and trace metal concentrations and physicochemical parameters were measured over a full... more Major ion and trace metal concentrations and physicochemical parameters were measured over a full tidal cycle in groundwater from reclaimed land adjacent to Rozelle Bay in Port Jackson, Sydney, Australia. Materials used for reclaiming the land (construction material waste or dredged marine sediment) predominantly influenced the ion and trace element compositions of the groundwater. The redox behaviour and composition of the soil profiles influenced the behaviour of redox-sensitive elements in the groundwater, for example Mn and Fe. When the water table recedes in drier periods, oxygen ingress can lead to biologically catalysed oxidation reactions resulting in a reduction in pH and an associated increase in the concentration of some trace elements. The dredged marine sediment contains a considerable fraction of shell fragments, leading to elevated bicarbonate levels in the groundwater, which in turn limits some trace element and major ion concentrations. The groundwaters contain high...
Water, Air, & Soil Pollution, 2004
Analyses of contaminant concentrations in soils are frequently carried out in urban regions becau... more Analyses of contaminant concentrations in soils are frequently carried out in urban regions because soils can act as both a sink and a secondary source of contaminants to the environment. Total soil concentration data are required to evaluate soil quality and the ability of soils to support life, however to determine the source and dispersion of contaminants and an accurate depiction of spatial distributions, normalised data are required. The effectiveness and economics of three normalisation methods for soils are tested in the current study. Size normalisation undertaken by physical separation of the fine fraction (<62.5 µm) provides consistent spatial information, but is time consuming and expensive and does not capture anthropogenic contributions associated with the coarse fraction of the soil, which is not generally analysed. Elemental normalisation only utilises a single analysis of the total soil, but requires that the normalising element acts conservatively, and as a proxy for the fine fraction, which are requirements not always met. A new post-extraction normalising procedure (PEN) also requires an analysis of the total soil only, but is not dependent on a normalising element and can be used to normalise any type of contaminant. In this approach, the residue after acid digestion is assumed to be the major diluent controlling the confounding effects of variable grain size. A strong relationship between the residue mass and soil size supports the use of this residue material as a normalising agent. Results indicate that the PEN method is equally efficient at reducing the confounding effects of variable grain size as elemental normalisation, but that size normalisation produces the most consistent spatial information and should be used in detailed studies of source and dispersion.
Environment International, 2003
Page 1. 69 Pittock A, 2005. Climate change: turning up the heat , CSIR O Publishing, Collingwood,... more Page 1. 69 Pittock A, 2005. Climate change: turning up the heat , CSIR O Publishing, Collingwood, Victoria. Pindyck RS, 2006. &#x27;Uncertainty in environmental economics&#x27;, NBER Working Paper 12752 , National Bureau of Economic Research, Cambridge, M assachusetts. ...
Marine Pollution Bulletin, 2003
Concentrations of dissolved metals (Cd, Cu, Ni, Mn and Zn) were determined for summer and winter,... more Concentrations of dissolved metals (Cd, Cu, Ni, Mn and Zn) were determined for summer and winter, under low-flow conditions in Port Jackson, a microtidal, well-mixed estuary in southeast Australia. Mean concentrations of Cd (0.04 AE 0.02 lg/l), Ni (0.86 AE 0.40 lg/l), Mn (20.0 AE 25 lg/l) and Zn (6.47 AE 2.0 lg/l) were below water quality guidelines. Concentrations of Cu (1.68 AE 0.37 lg/l), however, slightly exceeded recommended values. Dissolved Ni and Mn behaved mostly conservatively, whereas Cd, Cu and Zn showed mid-estuarine maxima. Peaks in Cd, Cu and Zn concentrations were located in the upper estuary, independent of the salinity and suspended particulate matter loading, and were consistent with anthropogenic inputs of metals in the estuary. Concentrations of dissolved Cu were highest in summer, whereas concentrations of Cd, Ni and Mn were significantly lower in summer than winter (P 6 0:05). The increase in temperature and biological activity during summer explained the seasonal variation. The sequence of log K d values (20-30 salinity) was Mn > Zn > Cu > Ni. These results give unique information concerning the contemporaneous distribution of dissolved trace metals in the Port Jackson estuary and they provide a data set against which the long-term contamination may be assessed.
Science of The Total Environment, Nov 1, 2023
93rd American Meteorological Society Annual Meeting, Jan 7, 2013
Treatise on Geomorphology
Normalised-metal data provide key information regarding the “health“ of an estuarine system, for ... more Normalised-metal data provide key information regarding the “health“ of an estuarine system, for example, the pristine condition, the magnitude of human-induced change, history of anthropogenic influence, future trends, and time required to reach managerial targets in sediment quality. Total-sediment metal concentrations are used to assess increasing risk to sediment quality, i.e., the ability to support a healthy benthos. Sedimentary metals provide an inexpensive and easily acquired means of making an initial assessment of estuarine health and provide the framework for more detailed and expensive investigations. Sediments should be included in a batch of indicators in estuarine evaluation where key indicators are assessed in a weight-of-evidence matrix.
Piantadosi, J., Anderssen, R.S. and Boland J. (eds) MODSIM2013, 20th International Congress on Modelling and Simulation, 2013
The Sydney estuary (Port Jackson) is a highly modified waterway in which surficial sediments are ... more The Sydney estuary (Port Jackson) is a highly modified waterway in which surficial sediments are extensively contaminated by a suite of chemicals including trace metals. These surficial sediments undergo resuspension into the water column on a daily basis due to both natural and anthropogenic processes which includes tides, currents, bioturbation, shipping, and dredging. As a result, sediment resuspension significantly increases the risk of trace metal contaminant exposure to marine biota. The status of trace metal contamination in surficial sediments, suspended particulate matter, and aquatic organisms has been studied in detail, and in all three media high concentrations have been detected, particularly for Cu, Pb, and Zn. However, a significant relationship linking these processes together has yet to be made and the effect that sediment-bound trace metals inflict on local fauna has not been documented previously. The current study aims to identify the processes controlling bioaccumulation of trace metal contaminants in Sydney estuary using laboratory-based mesocosm experiments. The native Sydney rock oyster (Saccostrea glomerata) was used as a bioindicator species and was exposed to contaminated suspended sediment at a range of controlled concentrations and loads to mimic previously observed field conditions. The oysters were analysed for total bioaccumulated tissue metal concentrations, as well as changes in protein expression to identify probable early-onset bioindicators. The results from the laboratory experiments will be used to parameterise a biogeochemical model to help explain the different mechanisms of trace metal bioaccumulation in Sydney estuary.
Marine Phosphorites, 1980
Page 1. SEPM SPECIAL PUBLICATION No 29 P 79 100 NOVEMBER 1980 A MODEL OF PENECONTEMPORANEOUS PHOS... more Page 1. SEPM SPECIAL PUBLICATION No 29 P 79 100 NOVEMBER 1980 A MODEL OF PENECONTEMPORANEOUS PHOSPHATIZATION BY DIAGENETIC AND AUTHIGENIC MECHANISMS FROM THE WESTERN MARGIN OF SOUTHERN AFRICA ...
effect on floods and droughts in Australia', Climatic change, vol. 25, pp. 289–317. Wilby R L... more effect on floods and droughts in Australia', Climatic change, vol. 25, pp. 289–317. Wilby R L, 2005. 'Uncertainty in water resource model parameters used for climate change impact assessment', Hydrological Processes, vol. 19, pp. 3201–3219. Young P, 2003. 'Top-down and data-based mechanistic modelling of rainfall-flow dynamics at the catchment scale', Hydrological Processes, vol. 17, pp. 2195–2217. Young W, Brandis K & Kingsford R, 2006. 'Modelling monthly streamflows in two Australian dryland rivers: matching model complexity to spatial scale and data availability', Journal of Hydrology, vol. 331, pp. 242–256. Zhang L, Dawes W R & Walker G R, 2001. 'Response of mean annual evapotranspiration to vegetation changes a catchment scale', Water Resources Research, vol. 37, pp. 701–708. Zhang L, Walker G R & Fleming M, 2002. 'Surface water balance for recharge estimation', CSIRO publishing, Collingwood, Victoria.
Environmental Science and Pollution Research, 2020
Narrabeen Lagoon is recognized as an Intermittently Closed and Open Lake or Lagoon (ICOLL) and is... more Narrabeen Lagoon is recognized as an Intermittently Closed and Open Lake or Lagoon (ICOLL) and is the largest coastal lagoon (2.2 km 2) in the Sydney metropolitan region. The catchment (53 km 2) supports five major river systems, and land use comprises of 56% residential, 42% parkland and 2% light industry, commercial, hospital and education. An initial screening environmental assessment was undertaken using sedimentary metals to determine the magnitude of anthropogenic change and level of ecological risk posed by these contaminants. Results illustrated an unusual example of an estuary significantly influenced by humaninduced change, but exhibiting minimal ecological risk. This anomaly was due to high anthropogenic metal concentrations in the fine fraction of surficial sediment, which was considerably diluted by abundant metal-poor coarse material resulting in reduced adverse ecological impact for total sediment. Predictive modelling to 2020 suggested that Pb concentrations will decline and Cu and Zn levels will increase slightly. Modelling of river discharge and analyses of fluvial sedimentary metals suggested stormwater derived from the most urbanized catchments and a major roadway combined with poor flushing explained surficial sediment metal distributions in the lagoon.
Treatise on Estuarine and Coastal Science, 2011
A suite of indicators covering biological, chemical, and physical realms is required for effectiv... more A suite of indicators covering biological, chemical, and physical realms is required for effective management and to ensure sustainability of highly sensitive regional assets in the coastal environment. Indicators need to be easily and inexpensively measured, be free of anthropogenic temporal and spatial influence, and have low natural variance. Sediment chemistry provides the pristine condition, the magnitude of anthropogenic change, and the risk of biological stress due to contaminants in the ecosystem. This chapter describes techniques used in the unambiguous assessment of these parameters and provides examples to demonstrate approaches.
Piantadosi, J., Anderssen, R.S. and Boland J. (eds) MODSIM2013, 20th International Congress on Modelling and Simulation, Dec 1, 2013
Sediments in Sydney estuary (Australia) and soils of the catchment are highly enriched in copper ... more Sediments in Sydney estuary (Australia) and soils of the catchment are highly enriched in copper (Cu), lead (Pb) and zinc (Zn) and these metals are accumulating in tissue of estuarine fauna. To reduce contamination levels, especially in the tissue of bivalve filter-feeders, it is necessary to understand the processes linking source, fate and effects of metals in these environments. It was the aim of the current work to identify key mechanisms controlling bioaccumulation in shellfish inhabiting this estuary by combining the results of existing individual models and monitoring data (oyster soft-tissue concentrations) describing various parts of this system into a single source-fate-effects model. Of the existing models, an atmospheric model (TAPM) showed that vehicle emissions were the major contributor of metals to catchment soils while stormwater modelling indicated that the average annual discharge from Sydney estuary catchment ranged 215,300-372,000 ML with associated loadings of 60,400, 30.5, 49.0 and 89.2 tonnes for total suspended solids (TSS), Cu, Pb and Zn, respectively. A verified hydrodynamic model investigated estuarine response to catchment rainfall and showed that freshwater plumes generated during high-rainfall events broke down within the estuary and that minimal (<1%) associated contaminants exited the estuary to the ocean, whereas TSS and pollutants delivered during low-rainfall were deposited close to discharge points and were trapped within the estuary. Oyster (Saccostrea glomerata) tissue was highly enriched in these metals, however there was no significant relationship with bottom sediment metal concentrations. The integrated model used here comprised a process-based framework describing the water and sediment balance coupled to a chemical (Cu) speciation model and an oyster bioaccumulation model. This integrated model is not spatially explicit on the horizontal plan but consists of two vertical components (aqueous layer and sediment). Early results of the source-fate-effects modelling indicate that the increase in dissolved and particulate organic ligands associated with a stormwater event entering the system appears unable to compensate for the concomitant increase in aqueous Cu and that the excess may be associated with dissolved inorganic ligands after the organic complexation sites have been exhausted. Modelling provides evidence that mechanisms driving pollution in the estuary are sensitive to catchment loading rates, which may result in highly variable soft-tissue Cu concentration in oysters.
Marine Pollution Bulletin, 2020
The detection rates of pharmaceuticals (Ps), personal care products (PCPs), current-use pesticide... more The detection rates of pharmaceuticals (Ps), personal care products (PCPs), current-use pesticides (CUPs) and a food additive (FA) in Brisbane River estuary (Queensland), Sydney estuary (New South Wales) and the Yarra River estuary (Melbourne, Victoria
Marine Pollution Bulletin, 2019
The influence of sedimentary metals on the cockle A. trapezia tissue was examined using a strong ... more The influence of sedimentary metals on the cockle A. trapezia tissue was examined using a strong difference in sedimentary metal concentrations in an embayment (Hen and Chicken Bay) highly contaminated in Cu and an adjacent cove (Iron Cove), strongly enriched in Cd, Cu, Pb and Zn within the heavily-urbanised Sydney estuary catchment (Australia). Statistically significant differences were recorded for cockle tissue metal concentrations between the study locations reflecting differences in surficial sediment metal concentrations. Low metal uptake was apparent in A. trapezia tissue, which were considerably less than background sedimentary concentrations and was of low-risk for human consumption. Dissimilar bioconcentration of Cd, Cu, Pb and Zn was apparent in tissue of cockles (A. trapezia), prawns (Metapenaeus bennettae), mussels (Mytilus galloprovincialis) and oysters (Saccostrea glomerata), due possibly to different feeding patterns and biogeochemical conditions in bottom sediments.
Marine and Freshwater Research, 2000
Trace metal (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) concentrations in the fine fraction (<62.5 µm) of... more Trace metal (Cd, Co, Cu, Fe, Mn, Ni, Pb, Zn) concentrations in the fine fraction (<62.5 µm) of surficial sediments adjacent to the major urban centres of Sydney, Newcastle and Wollongong on the central New South Wales (NSW) continental margin, Australia, are elevated above regional background. The nature of enrichment off these major urban centres is distinct. The fine fractions of sediments adjacent to Newcastle are enriched in Cd, Co, Cu, Fe, Mn, Ni, Pb and Zn, associated with the disposal of dredged harbour spoil in an offshore dumpsite, whereas adjacent to Sydney, enrichment of Cu, Pb and Zn in the fine fraction of sediments results mainly from the disposal of large volumes of sewage effluent. The source and regional dispersion of trace metals on the central-NSW continental margin can only be established from analysis of the fine fraction of the sediment, because total sediment distributions of contaminants are confounded by a highly variable sediment texture. Generally, low ...
Marine and Freshwater Research, 2003
The present study compared the geochemistry of saline and freshwater percolating through columns ... more The present study compared the geochemistry of saline and freshwater percolating through columns containing soils sampled from reclaimed land adjoining Sydney Harbour, Australia. The investigation assessed the flux of contaminants from the soil and, hence, estimated the affect of reclaimed land (using construction waste or dredged sediment) on the adjoining aquatic environment. Leachate samples were collected weekly for 22 weeks and were monitored for pH, Eh (redox potential), electrical conductivity, dissolved oxygen, major elements and heavy metals. In the early stages of the experiment (until approximately Week 12), the concentrations of the major elements in water percolating from the two columns were similar. Differing pseudo-steady-state conditions were reached in the columns after approximately 14 weeks. Sodium and Cl are weakly sorbed onto surface sites of the material in the saline column. The exchange of Na with other cations results in an increase in the aqueous concentra...
Marine and Freshwater Research, 2003
Major ion and trace metal concentrations and physicochemical parameters were measured over a full... more Major ion and trace metal concentrations and physicochemical parameters were measured over a full tidal cycle in groundwater from reclaimed land adjacent to Rozelle Bay in Port Jackson, Sydney, Australia. Materials used for reclaiming the land (construction material waste or dredged marine sediment) predominantly influenced the ion and trace element compositions of the groundwater. The redox behaviour and composition of the soil profiles influenced the behaviour of redox-sensitive elements in the groundwater, for example Mn and Fe. When the water table recedes in drier periods, oxygen ingress can lead to biologically catalysed oxidation reactions resulting in a reduction in pH and an associated increase in the concentration of some trace elements. The dredged marine sediment contains a considerable fraction of shell fragments, leading to elevated bicarbonate levels in the groundwater, which in turn limits some trace element and major ion concentrations. The groundwaters contain high...
Water, Air, & Soil Pollution, 2004
Analyses of contaminant concentrations in soils are frequently carried out in urban regions becau... more Analyses of contaminant concentrations in soils are frequently carried out in urban regions because soils can act as both a sink and a secondary source of contaminants to the environment. Total soil concentration data are required to evaluate soil quality and the ability of soils to support life, however to determine the source and dispersion of contaminants and an accurate depiction of spatial distributions, normalised data are required. The effectiveness and economics of three normalisation methods for soils are tested in the current study. Size normalisation undertaken by physical separation of the fine fraction (<62.5 µm) provides consistent spatial information, but is time consuming and expensive and does not capture anthropogenic contributions associated with the coarse fraction of the soil, which is not generally analysed. Elemental normalisation only utilises a single analysis of the total soil, but requires that the normalising element acts conservatively, and as a proxy for the fine fraction, which are requirements not always met. A new post-extraction normalising procedure (PEN) also requires an analysis of the total soil only, but is not dependent on a normalising element and can be used to normalise any type of contaminant. In this approach, the residue after acid digestion is assumed to be the major diluent controlling the confounding effects of variable grain size. A strong relationship between the residue mass and soil size supports the use of this residue material as a normalising agent. Results indicate that the PEN method is equally efficient at reducing the confounding effects of variable grain size as elemental normalisation, but that size normalisation produces the most consistent spatial information and should be used in detailed studies of source and dispersion.