Persistent organic pollutant (POPs) concentrations from great-winged petrels nesting in Western Australia

Marine animals that traverse coastal and offshore environments are potentially exposed to multiple sources of pollution. Baseline data of pollutant concentrations of these fauna are needed in remote areas as human populations grow and economic development increases because changes may affect local wildlife in unforeseen ways. Persistent organic pollutant (POPs) concentrations were quantified in an understudied seabird, the great-winged petrel (Pterodroma macroptera), that breeds in southern Western Australia. Organochlorine pesticides, polychlorinated biphenyls (PCBs), and novel brominated flame retardants (NBFRs) were measured in adults. Total POPs concentrations ranged 5.6-46.4 ng g^-1 ww. The most frequently detected POPs were the dichlorodiethyltrichloroethane (DDT) metabolite 4,4'DDE, the PCB CB-28, and the BFR polybrominated diphenyl ether BDE-99. These results contribute to the limited POPs data in marine fauna in this remote region, and the Southern Hemisphere, adding to the growing body of evidence that remote regions are affected by global trends of POPs distributions.

The use of biomimetic tools for water quality monitoring: passive samplers versus sentinel organisms

To evaluate the performance of artificial and biological integrative sampling strategies, dissolved concentrations of polychlorinated biphenyl (PCBs) and metals (Cu and Mn) were measured with passive sampler devices (PSD) enclosing hydrophobic and chelating phases, and Asiatic clams were transplanted to a polluted area in the Rio de la Plata. Water concentrations based on PSD were compared with spot water samples collected at 0, 15, 32, and 63 days of exposition. PCBs and metals displayed linear accumulation kinetics both in PSDs and bivalves, but with different slopes. PCBs slopes were 2-27 times higher in bivalves (0.3-7.9 vs. 0.1-2.6 ng g^-1 d^-1 in PSDs) reflecting active filtration and uptake from particles, colloids, and dissolved phase, whereas metal slopes were 2.5-11 times lower in bivalves (0.04-0.18 vs. 0.10-2.00 μg g^-1 d^-1 in PSDs) suggesting metal bioregulation. Truly dissolved PCB concentrations from PSD (4.0-6.9 ng.l^-1) represented average 13±4 % of PCB concentrations from filtered spot water samples reflecting the operational discrimination of the PSD diffusion membrane on competing dissolved and colloidal organic phases. In contrast, PSD dissolved Cu concentrations (2.3-8.2 μg l^-1) were equivalent to the spot water values (3.2-3.8 μg l^-1) suggesting that Cu speciation was adequately integrated by passive sampling. On the other hand, PSD-dissolved Mn concentrations (49±38 μg l^-1) were higher (p<0.05) than those from spot water samples (7±11μg l^-1) possibly due to phase changes of Mn distribution related to variable redox conditions in the water. Results evidenced that the PSDs are efficient accumulators of metals and organic compounds from the truly dissolved fraction.

Assessment of contaminant concentrations in sediments, fish and mussels sampled from the North Atlantic and European regional seas within the ICON project

Understanding the status of contaminants in the marine environment is a requirement of European Union Directives and the Regional Seas Conventions, so that measures to reduce pollution can be identified and their efficacy assessed. The international ICON workshop (Hylland et al., in this issue) was developed in order to test an integrated approach to assessing both contaminant concentrations and their effects. This paper describes and assesses the concentrations of trace metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls in sediments, mussels, and fish collected from estuarine, coastal and offshore waters from Iceland to the Mediterranean Sea. For organic contaminants, concentrations progressively increased from Iceland, to the offshore North Sea, to the coastal seas, and were highest in estuaries. Metals had a more complex distribution, reflecting local anthropogenic inputs, natural sources and hydrological conditions. Use of internationally recognised assessment criteria indicated that at no site were concentrations of all contaminants at background and that concentrations of some contaminants were of significant concern in all areas, except the central North Sea.

Occurrence and behavior of natural and anthropogenic (emerging and historical) halogenated compounds in marine biota from the Coast of Concepcion (Chile)

Fifty-five biota samples from the Coast of Concepcion (Chile) were analyzed for PBDEs, emerging brominated FRs, halogenated norbornenes and naturally-occurring MeO-PBDEs. PBDEs, MeO-PBDEs and halogenated norbornenes were detected at concentration levels ranging from 11 to 170, nd to 118 and nd to 5.8 ng/g lw, respectively. However, emerging brominated FRs such as decabromodiphenylethane (DBDPE), hexabromobenzene (HBB) and pentabromoethylbenzene (PBEB) were not detected in any sample. Bioaccumulation and bioconcentration processes were evaluated for the different families of compounds. Biomagnification factors (BMFs) were calculated, and some PBDE congeners (BDE-28, BDE-183 and BDE-209) as well as MeO-PBDEs presented BMF>1, being values of the naturally occurring MeO-PBDEs higher than those obtained for PBDEs. As regards halogenated norbornenes, BMF<1 were found.

Application of silicone rubber passive samplers to investigate the bioaccumulation of PAHs by Nereis virens from marine sediments

The availability of polycyclic aromatic hydrocarbons (PAHs) from marine sediments to the ragworm (Nereis virens) was studied. Concentrations of PAHs in pore waters were determined using silicone rubber passive samplers. Calculated bioconcentration factors confirmed that partitioning of PAHs between the lipid phase of the polychaetes and pore water is a passive process. Low biota-sediment accumulation factors (BSAF) calculated using total sediment concentration suggested a fraction of the total PAH burden in the sediment may be strongly sorbed to organic carbon and not available to the polychaete. Organic carbon normalised concentrations of the potentially exchangeable fractions of contaminants and freely dissolved concentrations (measured using silicone rubber samplers) provide a better description of the observed bioaccumulation by the ragworms. These data indicate that the concept of availability should be included in environmental risk assessments based upon equilibrium partitioning models, and that silicone rubber samplers can provide the necessary information for these models.

Persistent organic pollutants (PCB, DDT, HCH, HCB & BDE) in eels (Anguilla anguilla) in Scotland: current levels and temporal trends

Eels are an ideal biomonitor for persistent organic pollutants (POPs) because of their high lipid content, longevity and tendency to remain within a defined range during their freshwater life phase. This study investigated concentrations of POPs in eels (Anguilla anguilla) from 30 sites across Scotland, including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (BDEs), DDT (and metabolites), hexachlorocyclohexanes (alpha, beta, gamma-HCH), hexachlorobenzene (HCB), hexachlorobutadiene (HCBD) and pentachlorobenzene. Despite its EU-wide ban approximately 30 years ago, DDT and its derivatives were detected in almost all samples. PCB 153 and 138 were the most widely detected PCB congeners, while BDE 47 was the dominant BDE. Pentachlorobenzene was not detected, while HCBD was detected once only. alpha-HCH, beta-HCH and HCB concentrations were very low (generally <3 microg/kg or below detection). When compared with 1986 and 1995 data, the results revealed considerable decreases in p,p'-DDE concentrations. More drastic reductions were evident for gamma-HCH, reflecting the tightening restrictions on pesticide use imposed over the previous decades.

Hepatic gene expression in flounder chronically exposed to multiply polluted estuarine sediment: Absence of classical exposure 'biomarker' signals and induction of inflammatory, innate immune and apoptotic pathways

The effects of chronic long-term exposure to multiply polluted environments on fish are not well understood, but environmental surveys suggest that such exposure may cause a variety of pathologies, including cancers. Transcriptomic profiling has recently been used to assess gene expression in European flounder (Platichthys flesus) living in several polluted and clean estuaries. However, the gene expression changes detected were not unequivocally elicited by pollution, most likely due to the confounding effects of natural estuarine ecosystem variables. In this study flounder from an uncontaminated estuary were held on clean or polluted sediments in mesocosms, allowing control of variables such as salinity, temperature, and diet. After 7 months flounder were removed from each mesocosm and hepatocytes prepared from fish exposed to clean or polluted sediments. The hepatocytes were treated with benzo(a)pyrene (BAP), estradiol (E2), copper, a mixture of these three, or with the vehicle DMSO. A flounder cDNA microarray was then used to measure hepatocyte transcript abundance after each treatment. The results show that long-term chronic exposure to a multiply polluted sediment causes increases in the expression of mRNAs coding for proteins of the endogenous apoptotic programme, of innate immunity and inflammation. Contrary to expectation, the expression of mRNAs which are commonly used as biomarkers of environmental exposure to particular contaminants were not changed, or were changed contrary to expectation. However, acute treatment of hepatocytes from flounder from both clean and polluted sediments with BAP or E2 caused the expected changes in the expression of these biomarkers. Thus transcriptomic analysis of flounder exposed long-term to chronic pollution causes a different pattern of gene expression than in fish acutely treated with single chemicals, and reveals novel potential biomarkers of environmental contaminant exposure. These novel biomarkers include Diablo, a gene involved in apoptotic pathways and highly differentially regulated by both chronic and acute exposure to multiple pollutants.