Browsing by Author "Chariton, AA"

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    Ecotoxicological effects of decommissioning offshore petroleum infrastructure: a systematic review
    (Taylor & Francis, 2021-05-07) MacIntosh, A; Dafforn, KA; Penrose, B; Chariton, AA; Cresswell, T
    Successful decommissioning of subsea oil and gas infrastructure requires a safe and effective approach to assess and manage waste products. These products, often present as scale on internals of pipelines, include naturally occurring radioactive materials (NORM) and trace metals. Understanding the potential effects of these contaminants on marine fauna is crucial to managing global decommissioning. This review is composed of two aspects: 1) a systematic review was conducted to synthesize literature on all contaminants associated with decommissioned offshore structures and the effects of NORM contaminants on marine organisms; 2) a critical review of current environmental regulations for decommissioning and characterization of petroleum scale and NORM components. Studies defining the chemical and radiological contaminants associated with decommissioned structures were very limited. The main source of contaminants was identified from offshore platforms, with none from subsea structures. Only three studies measured variable chemical effects of radium to organisms from scale materials in subsea oil and gas infrastructure. No studies measured effects on organisms from other NORM, such as lead-210 and polonium-210. Currently, there are no international regulations on subsea pipeline closure, with NORM being underreported and not addressed in environmental impact assessments. This review highlights research gaps from environmental monitoring and characterization of NORM associated with decommissioned structures. Key recommendations for future research include characterizing NORM scale and assessing effects of scale to marine organisms through direct organism exposure experiments. This review emphasizes the need to incorporate ecotoxicology into environmental risk assessment for offshore petroleum decommissioning. © 2021 The Author(s). Published with license by Taylor & Francis Group, LLC.
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    The effect of dissolved nickel and copper on the adult coral Acropora muricata and its microbiome
    (Elsevier, 2019-04-03) Gissi, F; Reichelt-Brushett, AJ; Chariton, AA; Stauber, JL; Greenfield, P; Humphrey, C; Salmon, M; Stephenson, SA; Cresswell, T; Jolley, DF
    The potential impacts of mining activities on tropical coastal ecosystems are poorly understood. In particular, limited information is available on the effects of metals on scleractinian corals which are foundation species that form vital structural habitats supporting other biota. This study investigated the effects of dissolved nickel and copper on the coral Acropora muricata and its associated microbiota. Corals collected from the Great Barrier Reef were exposed to dissolved nickel (45, 90, 470, 900 and 9050 μg Ni/L) or copper (4, 11, 32 and 65 μg Cu/L) in flow through chambers at the National Sea Simulator, Townsville, Qld, Australia. After a 96-h exposure DNA metabarcoding (16S rDNA and 18S rDNA) was undertaken on all samples to detect changes in the structure of the coral microbiome. The controls remained healthy throughout the study period. After 36 h, bleaching was only observed in corals exposed to 32 and 65 μg Cu/L and very high nickel concentrations (9050 μg Ni/L). At 96 h, significant discolouration of corals was only observed in 470 and 900 μg Ni/L treatments, the highest concentrations tested. While high concentrations of nickel caused bleaching, no changes in the composition of their microbiome communities were observed. In contrast, exposure to copper not only resulted in bleaching, but altered the composition of both the eukaryote and bacterial communities of the coral's microbiomes. Our findings showed that these effects were only evident at relatively high concentrations of nickel and copper, reflecting concentrations observed only in extremely polluted environments. Elevated metal concentrations have the capacity to alter the microbiomes which are inherently linked to coral health. Crown Copyright ©2019. Published by Elsevier Ltd.
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    History of metal contamination in Lake Illawarra, NSW, Australia
    (Elsevier, 2015-01-01) Schneider, L; Maher, W; Potts, J; Gruber, B; Batley, GE; Taylor, A; Chariton, AA; Krikowa, F; Zawadzki, AW; Heijnis, H
    Lake Illawarra has a long history of sediment contamination, particularly by metals, as a result of past and current industrial operations and land uses within the catchment. In this study, we examined the history of metal contamination in sediments using metal analysis and 210Pb and 137Cs dating. The distributions of copper, zinc, arsenic, selenium, cadmium and lead concentrations within sediment cores were in agreement with historical events in the lake, and indicated that metal contamination had been occurring since the start of industrial activities in Port Kembla in the late 1800s. Most metal contamination, however, has occurred since the 1960s. Sedimentation rates were found to be 0.2 cm year−1 in Griffins Bay and 0.3 cm year−1 in the centre of the lake. Inputs from creeks bringing metals from Port Kembla in the northeast of the lake and a copper slag emplacement from a former copper refinery on the Windang Peninsula were the main sources of metal inputs to Lake Illawarra. The metals of highest concern were zinc and copper, which exceeded the Australian and New Zealand sediment quality guideline values at some sites. Results showed that while historical contamination persists, current management practices have resulted in reduced metal concentrations in surface sediments in the depositional zones in the centre of the lake.© 2015, Elsevier Ltd.
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    Recent history of sediment metal contamination in Lake Macquarie, Australia, and an assessment of ash handling procedure effectiveness in mitigating metal contamination from coal-fired power stations
    (Elsevier, 2014-08-15) Schneider, L; Maher, W; Potts, J; Gruber, B; Batley, GE; Taylor, A; Chariton, AA; Krikowa, F; Zawadzki, AW; Heijnis, H
    This study assessed historical changes in metal concentrations in sediments of southern Lake Macquarie resulting from the activities of coal-fired power stations, using a multi-proxy approach which combines 210Pb, 137Cs and metal concentrations in sediment cores. Metal concentrations in the lake were on average, Zn: 67 mg/kg, Cu: 15 mg/kg, As: 8 mg/kg, Se: 2 mg/kg, Cd: 1.5 mg/kg, Pb: 8 mg/kg with a maximum of Zn: 280 mg/kg, Cu: 80 mg/kg, As: 21 mg/kg, Se: 5 mg/kg, Cd: 4 mg/kg, Pb: 48 mg/kg. The ratios of measured concentrations in sediment cores to their sediment guidelines were Cd 1.8, As 1.0, Cu 0.5, Pb 0.2 and Zn 0.2, with the highest concern being for cadmium. Of special interest was assessment of the effects of changes in ash handling procedures by the Vales Point power station on the metal concentrations in the sediments. Comparing sediment layers before and after ash handling procedures were implemented, zinc concentrations have decreased 10%, arsenic 37%, selenium 20%, cadmium 38% and lead 14%. An analysis of contaminant depth profiles showed that, after implementation of new ash handling procedures in 1995, selenium and cadmium, the main contaminants in Australian black coal had decreased significantly in this estuary. © 2014, Elsevier B.V.
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    The response of corals and the coral microbiome to metal exposure
    (Society of Environmental Toxicology and Chemistry, 2017-11-12) Gissi, F; Reichelt-Brushett, AJ; Chariton, AA; Stauber, JL; Stephenson, SA; Cresswell, T; Greenfield, P; Severati, A; Humphrey, C; Jolley, DF
    The mining and production of Ni is increasing in tropical regions. The potential impacts of these activities on the valuable coastal ecosystems are poorly understood. Specifically, there is little information available on the effects of Ni to corals. Scleractinian corals are keystone species for coral reefs forming vital structural habitats that support other species, resulting in habitats with high species richness and diversity. For these reasons, it is important that future research provides data which can inform the sustainable development of Ni operations in tropical regions. This study aimed to investigate the effect of dissolved Ni exposure to the scleractinian coral Acropora muricata. Utilising the facilities at the National Sea Simulator (SeaSim), flow through chambers (2.5L) were used to test the effects of Ni and Cu on adult corals and its associated microbiota. Copper was tested alongside Ni to allow for comparisons with past studies. Four replicate chambers were used for; control, 50, 100, 500, 1000, 10000 µg/L Ni and 5, 20, 50, 100 µg/L Cu. Each replicate chamber contained 3 coral fragments (5-8cm in length). After a 96-h exposure, 1 fragment from each chamber was sacrificed for 3 different analytical purposes. One replicate was air blasted to remove tissues which were flash frozen and later used for DNA and RNA sequencing of the microbiota to observe if the bacterial community structure changed in response to metal exposure. A second fragment was air blasted to remove tissues, which were then acid digested and analysed by ICP-MS to determine metal concentrations in the coral tissues. A third replicate was frozen for subsequent metal uptake and distribution analyses using elemental mapping techniques including CT scanning and XRF-ITRAX. Control treatments remained healthy throughout the exposure. After 36 h, bleaching was observed in corals exposed to 50 and 100 µg Cu/L and 10000 µg Ni/L. At 96 h significant discolouration of corals was observed in Ni treatments 500 and 1000 µg Ni/L. The effects of Cu and Ni on adult corals and associated microbiota will be discussed.
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    To leave or not to leave: a tiered assessment of the impacts of scale residue from decommissioned offshore oil and gas infrastructure in Australia
    (ICRP, 2025-11-06) MacIntosh, A; Cresswell, T; Koppel, DJ; Hirth, GA; Tinker, R; Dafforn, KA; Chariton, AA; Penrose, B; Langendam, AD
    There are a range of potential options for the decommissioning of offshore petroleum infrastructure, including: complete removal; removal of topside infrastructure with subsea infrastructure left in situ; or partial removal or modification of infrastructure. The current decommissioning liability in Australia is estimated to exceed US$40 billion over the next 50 years. This is founded on the base-case regulatory position of complete removal of all infrastructure, with over half the liability occurring in the next 10 years. In Australia, a recently updated decommissioning framework requires that the planning for decommissioning begins from the outset of the project, and plans are matured throughout the life of operations. Successful decommissioning of subsea oil and gas infrastructure requires an effective and safe approach for assessing and managing chemical and radiological residues. Naturally occurring radioactive materials (NORM) are ubiquitous in oil and gas reservoirs around the world and may form contamination products including scales and sludges in topside and subsea infrastructure. In situ decommissioning of infrastructure left in the marine environment has many ecological benefits including establishment of artificial reefs, economic benefits from associated fisheries, reduced costs and improved human safety outcomes. However, there may be ecological risks associated with leaving infrastructures in the marine environment that are not well understood. Following a scenario of in situ decommissioning of subsea petroleum infrastructure, marine organisms occupying the exteriors or interiors of production pipelines may have close contact with the scale (metal and radionuclide contaminants). Consequently, radio- and chemo-toxicological effects from the scale could occur respectively. This paper considers the current assessment process for NORM-contamination products in oil and gas systems, recent and emerging Australian research in marine radioecology. Here we demonstrate a tiered approach to assess the ecological impacts of pipeline scale related to decommissioning practices, and identifies key research priorities. This can further aid our understanding of the fate of NORM contaminates in subsea oil and gas systems and guide Australia-specific (expand to other petroleum operating countries) risk assessments for infrastructure decommissioning options. The creation of a tiered assessment will enable industry to optimise decommissioning solutions and allow regulators to set clearer expectations on the requirements for environmental protection.