Polychlorinated dibenzodioxins/furans and dioxin-like polychlorinated biphenyls in fish and crustaceans of a recreationally fished estuary, following targeted remediation.

Polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) are a suite of harmful chemicals (hereafter collectively referred to as 'dioxins'), and their emission into aquatic habitats leads to persistent contamination of sediments, aquatic food-webs, and seafoods. Quantifying contaminant levels in seafood species is important for the ongoing management of exposure risk by fishers, particularly after any remediation actions. We present dioxin concentrations in four seafood species (Yellowfin Bream Acanthopagrus australis, Sea Mullet Mugil cephalus, Eastern School Prawn Metapenaeus macleayi, and Eastern King Prawn Penaeus plebejus) in a recreationally fished estuary, in relation to a contaminated site that has undergone a remediation process, partially removing contaminated sediments (Homebush Bay, Port Jackson, New South Wales, Australia). Dioxin concentrations in these species were measured before (2005/6) and after (2015/16) remediation at a range of locations in and around the remediated site. Dioxin concentrations and congener profiles differed substantially among taxa, and concentrations were frequently higher than Australian screening criteria. The two prawn species showed evidence of a decline in dioxin concentrations after remediation, but the fish species only showed a declining dioxin concentration with distance from the contaminated site (not between periods). There were some minor changes in the congener profile for some species following remediation. While there was evidence for greatly reduced dioxin concentrations in prawn species following remediation, the complex patterns for fish were likely affected by environmental changes, species-specific and temporal changes in lipid content, and animal movement patterns. Future monitoring may aid interpretation of the patterns and modelling of exposure risk associated with seafood consumption into the future.

Portable gas chromatography-mass spectrometry method for the in-field screening of organic pollutants in soil and water at pollution incidents.

Environmental pollution incidents generate an emergency response from regulatory agencies to ensure that the impact on the environment is minimised. Knowing what pollutants are present provides important intelligence to assist in determining how to respond to the incident. However, responders are limited in their in-field capabilities to identify the pollutants present. This research has developed an in-field, qualitative analytical approach to detect and identify organic pollutants that are commonly detected by regulatory environmental laboratories. A rapid, in-field extraction method was used for water and soil matrices. A coiled microextraction (CME) device was utilised for the introduction of the extracted samples into a portable gas chromatography-mass spectrometry (GC-MS) for analysis. The total combined extraction and analysis time was approximately 6.5 min per sample. Results demonstrated that the in-field extraction and analysis methods can screen for fifty-nine target organic contaminants, including polyaromatic hydrocarbons, monoaromatic hydrocarbons, phenols, phthalates, organophosphorus pesticides, and organochlorine pesticides. The method was also capable of tentatively identifying unknown compounds using library searches, significantly expanding the scope of the methods for the provision of intelligence at pollution incidents of an unknown nature, although a laboratory-based method was able to provide more information due to the higher sensitivity achievable. The methods were evaluated using authentic casework samples and were found to be fit-for-purpose for providing rapid in-field intelligence at pollution incidents. The fact that the in-field methods target the same compounds as the laboratory-based methods provides the added benefit that the in-field results can assist in sample triaging upon submission to the laboratory for quantitation and confirmatory analysis.

Levels of PCDD/Fs and dioxin-like PCBs in seafood from Sydney Harbour, Australia.

Sydney Harbour, Australia is contaminated with polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) due to a historical Union Carbide chemical manufacturing facility. We measured levels of PCDD/Fs and dl-PCBs in over 400 seafood samples (covering 20 species) collected throughout Sydney Harbour. Concentrations ranged from 0.1 to 193 pg total TEQ (WHO05)/g wet weight. These concentrations were above those considered safe for human consumption in many cases. Dioxin accumulation varied among species and was associated with life history traits. Mobile species had elevated concentrations throughout Sydney Harbour whereas accumulation in species likely to move less widely was dependent on the distance they were caught from the point source. This large scale study on multiple species of recreationally caught seafood resulted in the implementation of human consumption advisories for recreational fishing based on individual species and distance from point source. In addition, all forms of commercial fishing in Sydney Harbour were banned.

The freshwater bivalve Corbicula australis as a sentinel species for metal toxicity assessment: An in situ case study integrating chemical and biomarker analyses.

A weight of evidence approach in environmental assessment includes the use of biomonitor organisms to measure biologically available contaminant concentrations and lethal and sublethal responses in an exposure, dose, and response framework. Corbicula australis was assessed as a test species for metal toxicity using in situ river sediment exposures at 4 locations in the Molonglo River (New South Wales, Australia), which has a legacy of sediment metal contamination, following 8 decades of mining in its upper reaches. A sediment metal contamination gradient was evident from 12.5 km to 47 km downstream of the mine, as follows: zinc (851-130 mg/kg) > lead (104-7 mg/kg) > copper (31-5 mg/kg) > cadmium (2-0.3 mg/kg). Exposed C. australis accumulated the following metals in tissue: zinc (1358-236 µg/g) > copper (24-20 µg/g) > cadmium (4.7-0.7 µg/g) = lead (4.2-1.8 µg/g). Biomarker responses showed increased sublethal impairment with increased tissue metal concentrations. Total antioxidant capacity was mildly impaired, with corresponding increased lipid peroxidation and lysosomal membrane destabilization at the higher tissue metal concentrations. Corbicula australis proved to be an effective biomonitor organism for sediment metal assessment, as it is able to accumulate metals relative to sediment concentrations and showed a pattern of increased sublethal impairment with increased tissue metal concentration. It is recommended as a suitable species for incorporation into local freshwater monitoring and assessment programs. Environ Toxicol Chem 2017;36:709-719. © 2016 SETAC.

Sub-lethal effects of water-based drilling muds on the deep-water sponge Geodia barretti.

Offshore oil and gas activities can result in the discharge of large amounts of drilling muds. While these materials have generally been regarded as non-toxic to marine organisms, recent studies have demonstrated negative impacts to suspension feeding organisms. We exposed the arctic-boreal sponge Geodia barretti to the primary particulate components of two water-based drilling muds; barite and bentonite. Sponges were exposed to barite, bentonite and a natural reference sediment at a range of total suspended solid concentrations (TSS = 0, 10, 50 or 100 mg/L) for 12 h after which we measured a suite of biomarker responses (lysosomal membrane stability, lipid peroxidation and glutathione). In addition, we compared biomarker responses, organic energy content and metal accumulation in sponges, which had been continuously or intermittently exposed to suspended barite and natural sediment for 14 d at relevant concentrations (10 and 30 mg TSS/L). Lysosomal membrane stability was reduced in the sponges exposed to barite at 50 and 100 mg TSS/L after just 12 h and at 30 mg TSS/L for both continuous and intermittent exposures over 14 d. Evidence of compromised cellular viability was accompanied by barite analysis revealing concentrations of Cu and Pb well above reference sediments and Norwegian sediment quality guidelines. Metal bioaccumulation in sponge tissues was low and the total organic energy content (determined by the elemental composition of organic tissue) was not affected. Intermittent exposures to barite resulted in less toxicity than continuous exposure to barite. Short term exposures to bentonite did not alter any biomarker responses. This is the first time that these biomarkers have been used to indicate contaminant exposure in an arctic-boreal sponge. Our results illustrate the potential toxicity of barite and the importance of assessments that reflect the ways in which these contaminants are delivered under environmentally realistic conditions.

Resuspended contaminated sediments cause sublethal stress to oysters: A biomarker differentiates total suspended solids and contaminant effects.

Resuspended contaminated sediments represent an important route of contaminant exposure for aquatic organisms. During resuspension events, filter-feeding organisms are exposed to contaminants, in both the dissolved form (at the gills) and the particulate form (in the digestive system). In addition, these organisms must manage the physical stress associated with an increase in total suspended solids (TSS). To date, few studies have experimentally compared the contributions to biological stress of contaminated and clean suspended solids. The authors mixed field-collected sediments (<63 µm) from clean and contaminated field sites to create 4 treatments of increasing metal concentrations. Sydney rock oysters were then exposed to sediment treatments at different TSS concentrations for 4 d, and cellular biomarkers (lysosomal membrane stability, lipid peroxidation, and glutathione) were measured to evaluate sublethal toxicity. Lysosomal membrane stability was the most sensitive biomarker for distinguishing effects from resuspended contaminated sediments, as increasing amounts of contaminated TSS increased lysosomal membrane destabilization. The authors' results illustrate the importance of considering contaminant exposures from resuspended sediments when assessing the toxicity of contaminants to aquatic organisms.

A biomarker of contaminant exposure is effective in large scale assessment of ten estuaries.

Cost-effective and sensitive measures of anthropogenic stress are necessary tools in any environmental monitoring program. When implementing new monitoring tools in a region, rigorous laboratory and field studies are essential for characterizing the sensitivity and efficacy of the approach. We exposed the oyster Saccostrea glomerata to various individual contaminants through multiple exposure pathways (water- and food-borne) in the laboratory and measured two biomarker responses, lysosomal membrane stability (LMS) and lipid peroxidation (LPO). LMS was sensitive to both contaminant exposure pathways. We subsequently measured this biomarker in oysters which had been experimentally deployed at multiple sites in each of ten estuaries with varying levels of contamination associated with re-suspended sediments. There was a strong association between LMS and metal exposure, despite substantial natural variation in water quality parameters. Our results illustrate the potential use of LMS as a pragmatic indicator of biotic injury in environmental monitoring programs for re-suspended contaminated sediments.

Lifetime PCB 153 bioaccumulation and pharmacokinetics in pilot whales: Bayesian population PBPK modeling and Markov chain Monte Carlo simulations.

Physiologically based pharmacokinetic (PBPK) models for wild animal populations such as marine mammals typically have a high degree of model uncertainty and variability due to the scarcity of information and the embryonic nature of this field. Parameters values used in marine mammals models are usually taken from other mammalian species (e.g. rats or mice) and might not be entirely suitable to properly explain the kinetics of pollutants in marine mammals. Therefore, several parameters for a PBPK model for the bioaccumulation and pharmacokinetics of PCB 153 in long-finned pilot whales were estimated in the present study using the Bayesian approach executed with Markov chain Monte Carlo (MCMC) simulations. This method uses 'prior' information of the parameters, either from the literature or from previous model runs. The advantage is that this method uses such 'prior' parameters to calculate probability distributions to determine 'posterior' values that best explain the field observations. Those field observations or datasets were PCB 153 concentrations in blubber of long-finned pilot whales from Sandy Cape and Stanley, Tasmania, Australia. The model predictions showed an overall decrease in PCB 153 levels in blubber over the lifetime of the pilot whales. All parameters from the Sandy Cape model were updated using the Stanley dataset, except for the concentration of PCB 153 in the milk. The model presented here is a promising and preliminary start to PBPK modeling in long-finned pilot whales that would provide a basis for non-invasive studies in these protected marine mammals.

Assessing levels of halogenated organic compounds in mass-stranded long-finned pilot whales (Globicephala melas) from Australia.

Pollution is a threat to the health of marine mammals worldwide. Mass-strandings are poorly understood, but often involve pilot whales. However, there is limited information regarding pollution in long-finned pilot whales from Australia. Consequently, the profiles and levels of several pollutant classes were investigated in blubber of Tasmanian long-finned pilot whales. DDX levels were highest in all groups, followed by PCBs or MeO-PBDEs and lowest for PBDEs. The concentrations of all pollutants decreased with age in males. This is at least partly due to the growth dilution effect although it might also be caused by decreasing levels of PCBs, PBDEs, DDXs, HCB and CHLs in the environment. Fetus/mother ratios of higher chlorinated PCBs increased with the duration of pregnancy suggesting a preference for offloading via gestation rather than through lactation. Overall, the highest pollutant levels were found in the youngest animals.

Indicators of environmental stress: cellular biomarkers and reproductive responses in the Sydney rock oyster (Saccostrea glomerata).

We measured a suite of common biomarker responses for the first time in the Sydney rock oyster Saccostrea glomerata to evaluate their utility as biological effects measures for pollution monitoring. To examine the relationship between biomarker responses and population level effects, fertilisation and embryo development assays were also conducted. Adult oysters were deployed in two contaminated estuaries and a reference estuary in Sydney, Australia. The concentrations of various contaminants (metals and polycyclic aromatic hydrocarbon, PAHs) were quantified in oyster's tissue from each site and both metals and total PAHs were significantly elevated in contaminated estuaries relative to the reference estuary. Lysosomal membrane destabilisation, lipid peroxidation levels and glutathione (GSH) concentrations were measured in the digestive gland of oysters. Of all biomarkers measured, lysosomal membrane destabilisation proved to be the most useful indicator of oysters facing anthropogenic stress and we suggest this may be an especially useful biomarker for incorporation into local environmental monitoring programs. Moreover, lysosomal membrane destabilisation showed good correlations with fertilisation, normal embryo development and estuary status. GSH and lipid peroxidation were not as valuable for distinguishing between estuaries exposed to differing levels of anthropogenic stress, but did provide additional valuable information regarding overall health status of the oysters.

Perfluorinated alkyl acids in water, sediment and wildlife from Sydney Harbour and surroundings.

Perfluorinated alkyl compounds (PFCs) including perfluorooctane sulphonate (PFOS) and perfluorooctanoate (PFOA) were measured in environmental samples collected from around Homebush Bay, an urban/industrial area in the upper reaches of Sydney Harbour and Parramatta River estuary. Water, surface sediment, Sea Mullet (Mugil cephalus), Sydney Rock Oyster (Saccostrea commercialis) and eggs of two bird species; White Ibis (Threskiornis molucca), and Silver Gull (Larus novaehollandiae) were analysed. In most samples PFOS was the dominant PFC. Geometric mean PFOS concentrations were 33 ng/gww (wet weight) in gull eggs, 34 ng/gww in ibis eggs, and 1.8 ng/gww and 66 ng/gww in Sea Mullet muscle and liver, respectively. In sediment the PFOS geometric mean was 1.5 ng/g, in water average PFOS and PFOA concentrations ranged from 7.5 to 21 ng/L and 4.2 to 6.4 ng/L, respectively. In oysters perfluorododecanoic acid was most abundant, with a geometric mean of 2.5 ng/gww.