Dioxins and PCBs in Greenland shark (Somniosus microcephalus) from the North-East Atlantic

The Greenland shark (Somniosus microcephalus) is a high-trophic fish species present in Arctic waters. The present study aimed to determine concentrations of polychlorinated dibenzo-p-dioxins and furans (PCDDs/Fs), dioxin-like (DL) PCBs and six non-dioxin-like (NDL) PCBs in muscle and liver from 10 female Greenland sharks collected between 2001 and 2003 from Icelandic waters. The mean total concentrations of PCDDs/Fs were 13 and 530pg/g fat for muscle and liver, respectively, and show enrichment in the liver. Concentrations of DL-non-ortho PCBs were also higher in liver compared to muscle with mean concentrations of 7.8 and 0.36ng/g fat, respectively. No enrichment in the liver was found for DL-mono-ortho- and NDL-PCBs. No correlation was found between the size range studied and total concentrations of the compounds analyzed. Total WHO-TEQs (PCDDs/Fs and DL-PCBs) ranged between 7.1-70 and 54-1500pg/g fat in muscle and liver, respectively.     

Biomonitoring of organochlorine compounds and trace metals along the Eastern Adriatic coast (Croatia) using Mytilus galloprovincialis

The paper presents the results of monitoring trace organic contaminants (17 PCBs and 7 OCPs) and 6 trace metals (Cd, Cr, Cu, Hg, Pb and Zn) in the coastal waters of the eastern Adriatic in 2006 using Mytilus galloprovincialis as indicator species. OCPs were found in all samples (0.07-14.3 ng g⁻¹ d.wt.), while in positive samples concentrations of PCBs ranged between 0.16 and 20.5 ng g⁻¹ d.wt. The α-HCH/γ-HCH and DDE/DDT ratios indicated recent input of γ-HCH and DDT. Spatial distributions of HCB, PCBs, DDTs and Hg were significantly correlated with population density. Although elevated concentrations of all trace metals and organic contaminants were recorded in the densely populated and industrialized areas, overall data point to relatively low level of contamination of the eastern Adriatic coast. Evaluation of the risks to human health associated with consumption of the mussels suggested that there is no health risk for moderate shellfish consumers.     

Biomagnification of persistent chlorinated and brominated contaminants in food web components of the Yellow Sea

Concentrations of polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and polybrominated diphenyl ethers (PBDEs) were measured in 32 species inhabiting the Yellow Sea to assess their bioaccumulation potentials. The concentrations in these samples were lower than those reported for other countries or locations. Relatively high levels of BDE 209 in biota suggest an ongoing source of deca-BDE technical mixing within the Yellow Sea. The accumulation profiles of PCBs were uniform between species, but the concentrations of OCPs and PBDEs varied widely. Pelagic and benthic food-chain components were separated by their δ¹³C values. Significant positive correlations between δ¹⁵N and PCB 153, PCB 138, p,p′-DDE, oxy-chlordane, and trans-nonachlordane were found only for pelagic consumers, indicating that the pelagic food chain is an important bioaccumulation pathway for selected PCB and OCP compounds. The other compounds did not show any biomagnification through benthic and pelagic food chains, suggesting the lower bioaccumulation potentials of these contaminants.     

Persistent organochlorine residues and toxic evaluation of polychlorinated biphenyls in sharks from the Mediterranean Sea (Italy)

Persistent organochlorines such as polychlorinated biphenyls including coplanar congeners, DDT compounds and HCB were measured in different tissues (muscle, liver and eggs) of two Mediterranean shark species: namely Centrophorus granulosus and Squalus blainvillei. The concentrations of organochlorines in the tissues and organs of both species were in the order DDTs>PCBs>HCB. The highest values of DDTs, PCBs and HCB were found in liver followed by eggs and muscle. Among DDTs the compound found in greatest concentration was p,p^′-DDE. The PCB profiles were dominated by congeners 138, 153, and 180. The isomers with higher TEQs values were non- and mono-ortho congeners than di-ortho ones in muscle, liver and eggs of both species. Among the non-ortho, PCB 126 was the major contributing individual to the total TEQs in both species.     

Metal contaminants for modelling lobster (Homarus americanus) migration patterns in the Inner Bay of Fundy, Atlantic Canada

A method, which uses metal compositions in lobster digestive glands as natural environmental tags, has been developed to trace lobster movements. Lobsters were collected from three selected sites, Minas Channel, Minas Basin, and Cobequid Bay, Inner Bay of Fundy, New Brunswick, Canada, that were known to be contaminated with Cu. Five metal variables (Ag, Cd, Cu, Mn and Zn) were processed for principal component analysis (PCA). Metal concentration and burden models were investigated and PCA was able to differentiate lobsters from the respective catch sites. The method was applied to investigate the May and June lobsters collected at the three sites to determine the migration rate during this period of the fishing season. The results show a high level of mixing at Minas Basin and Cobequid Bay in June, and lobster movement inward toward the inner reaches of the bay, with very limited movement outward from the inner bay.     

Organohalogen contaminants in finless porpoises (Neophocaena phocaenoides) from Korean coastal waters: Contamination status, maternal transfer and ecotoxicological implications

Information on the occurrence of organochlorine compounds (OCs) and polybrominated diphenyl ethers (PBDEs) in marine mammals from Korea is scarce. In this study, OCs and PBDEs were determined in the blubber of 52 finless porpoises (Neophocaena phocaenoides) from Korean coastal waters. The highest contamination was found for DDTs, followed by PCBs, PBDEs, HCHs, CHLs and HCB. Concentrations of OCs in finless porpoises were lower than those reported worldwide, but PBDE contamination was comparable to other studies, due to ongoing use of PBDE products in Korea. Significant gender-specific differences were found for concentrations and accumulation profiles of OCs and PBDEs, due to maternal transfer and lactation of mature females. The BDEs 49 and 66 comprised 4-16% of total PBDEs in finless porpoises, which seems to be associated with debromination of higher BDEs. The DDT levels in Korean finless porpoises have almost reached the levels associated with immunosuppression in marine mammals.     

Organohalogen contaminants in striped dolphins (Stenella coeruleoalba) from Japan: Present contamination status, body distribution and temporal trends (1978-2003)

Organohalogen contaminants including PCBs, DDTs, CHLs, HCHs, HCB, PBDEs and HBCDs were determined in striped dolphins (Stenella coeruleoalba) found stranded at Gogo-shima (n = 6, 2003) and collected from Taiji (n = 15, 1978-1992) in Japan. All target compounds were significantly detected in all the specimens, indicating ubiquitous contamination of oceanic cetaceans in northwest Pacific Ocean. Examination of body distribution of organohalogens in the six specimens from Gogo-shima showed no significant difference in concentrations among the analyzed tissues, except for brain, which had lower levels possibly due to the existence of blood-brain barrier. For evaluating temporal trends, archived blubber samples of adult male stripped dolphins collected in 1978, 1979, 1986 and 1992 were analyzed. Concentrations of PCBs, DDTs and HCHs did not change significantly during 1978-2003. In contrast, remarkable increasing trends of PBDEs and HBCDs were observed, suggesting growing consumption in Japan and surrounding countries in recent years.     

Using blood samples to estimate persistent organic pollutants and metals in green sea turtles (Chelonia mydas)

Persistent organic pollutants (POPs) and heavy metals have been reported in a number of green turtle (Chelonia mydas) populations worldwide. However, due to ethical considerations, these studies have generally been on tissues from deceased and stranded animals. The purpose of this study was to investigate the use of blood samples to estimate the tissue contamination of live C. mydas populations. This study analysed 125 POP compounds and eight heavy metals in the blood, liver, kidney and muscle of 16 C. mydas from the Sea World Sea Turtle Rehabilitation Program, Gold Coast, Australia. Strong correlations were observed between blood and tissue concentrations for a number of POPs and metals. Furthermore, these correlations were observed over large ranges of turtle size, sex and condition. These results indicate that blood samples are a reliable non-lethal method for predicting chemical contamination in C. mydas.     

Early contamination of European flounder (Platichthys flesus) by PCDD/Fs and dioxin-like PCBs in European waters

Contamination levels and profiles of 7 polychlorinated-p-dioxins, 10 polychlorinated furans (PCDD/Fs) and 12 dioxin-like polychlorinated biphenyls (dl-PCBs) were investigated in juvenile European flounder (Platichthys flesus) captured in different nursery areas in the northeastern Atlantic coast across its geographical distribution range. The toxic equivalent concentrations (WHO-TEQ_fish) were also determined in order to evaluate which P. flesus population was more exposed to dioxin-like toxicity. Juveniles caught in the Sørfjord (Norway) showed the lowest WHO-TEQ_fish concentration (0.052 pg WHO-TEQ_fish g⁻¹ wet weight) whereas the highest value was observed in fish from the Wadden Sea (The Netherlands; 0.291 pg WHO-TEQ_fish g⁻¹ ww), mainly due to the greater contribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin, the most toxic congener. Nonetheless, when comparing the results with existent tissue residue-based toxicity benchmarks, no adverse effects resulting from PCDD/Fs and dl-PCBs are expected to occur in flounder from the studied systems.     

The discrepancy in concentration of metals (Cu,Pb and Zn) in oyster tissue (Saccostrea glomerata) and ambient bottom sediment (Sydney estuary,Australia)

The current study aimed to examine the relationship between metals in sediments and metal bioaccumulation in oyster tissue in a highly-modified estuary (Sydney estuary, Australia). While extensive metal contamination was observed in surficial sediments, suspended particulate matter and oyster tissue, a significant relationship between these media could not be established. No relationship was determined between sediment quality guidelines and oyster size or weight, nor with human consumption levels for metals in oyster tissue. Moreover, oyster tissue metal concentrations varied greatly at a single locality over temporal scales of years. Oyster tissue at all 19 study sites exceeded consumptions levels for Cu. Bioaccumulation of metals in oyster tissue is a useful dynamic indicator of anthropogenic influence within estuaries, however oysters cannot be used in Sydney estuary as a valid biomonitor due to overriding internal regulation (homoestasis) by the animal, or by external natural (sediment resuspension) and anthropogenic (sewer/stormwater discharges) pressures, or both.     

PCBs and organochlorine pesticides in Hector’s (Cephalorhynchus hectori hectori) and Maui’s (Cephalorhynchus hectori maui) dolphins

Polychlorinated biphenyls (PCBs) and organochlorine (OC) pesticide levels were determined in blubber samples collected from stranded and incidentally by-caught Hector’s (Cephalorhynchus hectori hectori) and Maui’s (Cephalorhynchus hectori maui) dolphins from New Zealand waters between 1997 and 2009. PCBs (45 congeners) and a range of OC pesticides including dieldrin, hexachlorocyclohexane (HCH) and dichlorodiphenyltrichloroethane (DDT), along with its metabolites DDE and DDD were determined. OC pesticides dieldrin, p,p′-DDE, p,p′-DDD and p,p′-DDT were present at the highest concentrations. Sum DDT concentrations ranged from 93.7 to 8210 (Mean = 1358, S.D = 1974) and 252.4 to 57,390 (Mean = 12,389, S.D = 18,161) μg/kg wet weight in females and males, respectively. Similarly, Σ45CB concentrations ranged from 45.5 to 981.3 (Mean = 333.2, S.D = 265.8) and 60.5 to 5574 (Mean = 1833, S.D = 1659) μg/kg wet weight in females and males, respectively. The transfer of ΣDDTs and summed PCBs (both as ΣICES7CBs and Σ45CBs) between a pregnant female and her unborn fetus was calculated at 5.7% and 4.3%, respectively. As the fetus was close to term, this likely represents the degree of placental transfer. Concentrations of OC pesticides determined in the present study are higher than those previously reported for Hector’s dolphins. Sum DDT and DDE/ΣDDT levels calculated reveal New Zealand’s legacy of DDT usage, particularly off the east coast of the South Island.     

Chlorobiphenyls in the blubber of harbour porpoises (Phocoena phocoena) from the UK: Levels and trends 1991-2005

Harbour porpoises sampled within the UK Cetacean Strandings Investigation Programme have been analysed for 25 chlorobiphenyl congeners. In all, 440 porpoises stranded or bycaught during the period 1991-2005 were studied. There are regional differences in the trend in summed congener concentrations over time but, despite controls on PCBs having been in place for decades, they are declining only slowly. Their toxic impacts in UK porpoises - increased susceptibility to infectious disease mortality in the most contaminated individuals - looks likely to continue for some time yet. Further efforts to limit or eliminate PCB discharges to the marine environment are still needed.     

A study of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in the livestock waste compost of Hong Kong, PR China

Composting is one of the waste disposal methods adopted for disposal of livestock waste in Hong Kong. The composting livestock waste normally undergoes 6–8 weeks fermentation, followed by 16–20 weeks maturation. The matured compost is sold as soil conditioner in the local market. In 2006, feedstock material and a time-series of compost samples were collected throughout the fermentation and maturation process from the Sha Ling Composting Plant in the New Territories. The feedstock material and compost samples were analyzed for contents of three unintentional persistent organic pollutants (POPs), i.e. dioxins/furans, dioxin-like PCBs and total PCBs. These POPs are unintentionally produced by-products of chemical industrial processes and combustion processes. Selected heavy metals were also analyzed, which served as conservative tracers to determine potential mass loss during the composting process. Levels of contamination by these POPs were found to be low in the matured compost for sale. The mean concentrations (lower–upper bound) of total dioxins/furans, total dioxin-like PCBs and total PCBs were 2.01–2.05 ng I-TEQ/kg dw, 0.04–0.05 ng WHO-TEQ/kg dw and 1.55–1.55 μg/kg dw, respectively. Progressively elevated levels of these POPs were observed in the compost samples during the fermentation process. Analysis of the congener profiles revealed that the heptaCDD and octaCDD were the main contributors to the observed increase in dioxin/furan content. The possible sources of dioxins/furans in the compost were discussed. The study results established a local dioxins/furans emission factor specific to the trade and provided a better estimate of the annual dioxins/furans emission for the livestock waste composting activity in Hong Kong.     

First record of sea snake (Hydrophis elegans, Hydrophiinae) entrapped in marine debris

Entanglement in derelict fishing gear and other marine debris is a major threat to the survival of large marine wildlife like cetaceans, seabirds and sea turtles. However, no previous reports of entanglement or entrapment have been recorded in sea snakes (Hydrophiinae). We report here on a sea snake (Hydrophis elegans) found with a ceramic washer encircling its body captured from the north-east coast of Queensland, Australia. The ring had constricted the body and over time caused extensive damage to the underlying tissues. A post-mortem examination showed the snake was severely emaciated as the ring restricted the passage of food to the stomach and intestine. This is the first record of mortality due to marine debris entrapment in sea snakes.     

Assessing the spatial variability,level and source of organic chemical contaminants in bivalve fishing grounds on the Galician coast (NW Spain)

Polychlorinated biphenyls, organochlorine pesticides, organotin compounds and triazines were quantified in sediments and bivalves collected in four areas on the Galician coast. One or several species were analysed at each site depending on their availability, including mussels (Mytilus galloprovincialis), cockles (Cerastoderma edule), clams (Venerupis pullastra and Ruditapes decussatus) and razor shells (Ensis siliqua). The general spatial distribution of contaminants was consistent in spite of the different sources of contamination. High inter-species variability was also observed. M. galloprovincialis and V. pullastra showed the highest levels of contaminants and intra-spatial variability, which highlights them as suitable species to be used as sentinel organisms. The area of O Burgo showed some worrisome results: PCB sediment concentrations were within the range that could cause biological effects. Also the level of heptachlor observed in V. pullastra was above limits accepted on edible seafood. Finally TBT concentration in mussels correlated with concentrations causing imposex in snails.     

Mercury bioaccumulation in the spotted dogfish (Scyliorhinus canicula) from the Atlantic Ocean

The annual and life-cycle mercury bioaccumulation pattern in selected tissues of the economically relevant Elasmobranchii species Scyliorhinus canicula was studied, and the risks associated with its consumption evaluated.Preferential mercury bioaccumulation occurred in muscle tissue, and followed the order muscle > heart > liver > gills > pancreas. Total mercury in muscle tissue ranged from 0.13 mg kg⁻¹ (wwt) in 1+ year old males to 0.8 mg kg⁻¹ (wwt) in 8+ year old mature females, with no significant differences found between genders, and no clear lifespan bioaccumulation pattern observed, except for mature females. Organic mercury in the muscle ranged from 0.05 mg kg⁻¹ (wwt) to 0.52 mg kg⁻¹ (wwt), corresponding to an average of 70% of total mercury content. In mature females, a significant correlation (R = 0.99, P = 0.01) was found between size and organic mercury fraction, suggesting reproduction as an important factor controlling organic mercury bioaccumulation in the spotted dogfish.     

Polychlorinated biphenyl (PCB) concentrations and congener composition in masu salmon from Japan: A study of all 209 PCB congeners by high-resolution gas chromatography/high-resolution mass spectrometry (HRGC/HRMS)

We collected two subspecies of masu salmon: Oncorhynchus masou masou from four localities (southern Sea of Japan northward to Hokkaido) and O. masou ishikawae from upstream from Ise Bay close to a heavy industrial area. All 209 PCB congeners were analyzed using HRGC/HRMS. PCA ordination of congener concentrations divided data into three groups: (i) ssp. masou from Hokkaido, (ii) ssp. masou from the other regions and (iii) ssp. ishikawae. The highest ∑ PCB concentration (40.39 ng/wet wt) was in ssp. ishikawae followed by ssp. masou from southern waters; however the TEQ_{dioxin-like PCBs} was highest in ssp. masou from southern water (1.96 pg-TEQ_{dioxin-like PCBs}/g wet wt.) due to the high proportion of congener #126 in its complement (#126 has the highest toxic equivalency factor among congeners). There is likely a contamination source offshore in the southern Sea of Japan and/or along the migratory route of ssp. masou.     

Distribution and sources of organochlorinated contaminants in sediments from Izmir Bay (Eastern Aegean Sea)

Eighteen surface sediment samples representative of the entire Izmir Bay were analyzed for organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs). This was in order to provide extensive information concerning the recent deposition of these compounds in this area, together with levels, distribution, possible sources and potential biological risk. Sites that were contaminated by high concentrations of organochlorine compounds were associated with dense population, such as the harbour and the Gediz River estuary. Relatively higher ΣDDT concentrations and high DDT/DDE + DDD ratios in the Gediz River estuary indicated DDT usage, probably linked to public health emergencies. According to the established guidelines for sediment quality, the risk of adverse biological effects from such levels of OCPs and PCBs as recorded at most of the study sites was insignificant. But the higher concentrations in Inner bay and in the Gediz River estuary could cause biological damage.