Derived concentration factors for caesium-137 in edible species of North Sea fish

Concentration factor (CF=Bq kg⁻¹ fillet/Bq kg⁻¹ filtered sea water) values for ¹³⁷Cs in fillets of cod (Gadus morhua), haddock (Merlanogrammus aeglefinus), plaice (Pleuronectes platessa) and whiting (Merlangius merlangius), were derived from fish and filtered seawater concentrations. Samples were collected in twelve sampling boxes in the North Sea over an eight-year period—1978–1985. The range of results with species, between species, and between surveys are discussed. Mean CF values of 92, 58, 39, and 150 were found in cod, haddock, plaice, and whiting respectively. These support the IAEA recommended CF value of 100 for fish in generalised dose assessments.     

DNA integrity as a biomarker of marine pollution: Strand breaks in seastar (Asterias rubens) and dab (Limanda limanda)

DNA strand breaks in seastars and dab were measured by the time-dependent partial alkaline unwinding of DNA followed by the determination of the double-stranded to total DNA ratio (F-value). Highest DNA integrity (0.75 < F < 0.85) was found in seastars from offshore reference sites, whereas lowest integrity (0.35 < F < 0.55) was identified in specimens from the coastal zone and certain expected uncontaminated offshore areas. A significant correlation existed between the fraction of double-stranded DNA and the concentration of low chlorinated biphenyl congeners and with H atoms substituted in the meta and para position of the biphenyl skeleton. Over 90% of double-stranded DNA was measured in dab obtained from pristine areas, with an average F-value in specimens from most sampling stations varying from 0.75 to 0.85, during August/September 1991. Samples taken in May/June 1992 showed significantly lower DNA integrity (0.55 < F < 0.70 in most stations). A significant decrease of the integrity was established with increase in concentration of the congeners (tri to hepta chloro substituted and with or without a H atom substituted in the meta and para position).     

Screening of Mercury and Persistent Organochlorine Pollutants in Long-Finned Pilot Whale (Globicephala melas) in the Faroe Islands

Results of mercury and organochlorine analyses in pooled muscle and blubber samples representing in all 417 long-finned pilot whales (Globicephala melas) sampled in 1997 in the Faroe Islands are presented. The 28 pooled muscle samples from (in all) 9 pods were analysed for total mercury and the same number of pooled blubber samples were analysed for PCB (IUPAC CBs no. 28, 52, 99, 101, 105, 118, 128, 138, 153, 170, 180, 183 and 187), p,p′-DDT and metabolites and o,p′-DDT and metabolites, cis () and trans (γ)-chlordane, cis- and trans-nonachlor, oxychlordane, mirex, hexachlorobenzene, β-HCH and toxaphene (Parlars no. 26 (T2), 32, 50 (T12), 62 (T20) and 69.     

Tissue distribution of mercury in normal and abnormal young Common Terns

Sixteen young Common Terns (Sterna hirundo) from colonies on the south shore of Long Island, New York, had fairly consistent levels and tissue distribution patterns of total mercury in blood, liver, kidney, muscle, brain and feathers. Levels were highest in liver, blood and feathers, and were lower in muscle and brain. The latter two tissues showed low variability across birds, suggesting that they are more static repositories for mercurial compounds. Only slight, non-significant increases were detected in chicks 10–30 days old compared with 1–9 day olds. Four chicks with abnormal feather loss had significantly higher mercury levels than 12 normal chicks. The average intercorrelation among tissues was highest for liver (mean r² = 0.40) and blood (mean r² = 0.38). Liver is probably the single best tissue to serve as a surrogate for all others, due to high correlation with other tissues, large size, and ready availability. Use of a single tissue allows one to focus a study in greater detail and at lower cost than if several tissues were assayed.     

Methyl mercury, total mercury, and selenium in snapper from two areas of the New South Wales coast, Australia

The muscle tissue of snapper (Chrysophrys auratus: Sparidae) from two areas of the New South Wales coast was analysed for methyl mercury, total mercury and selenium concentrations (134 samples from the Sydney area and 186 samples from the Nowra area, about 120 km to the south of Sydney).

The Sydney snapper ranged from 0.08 to 1.66 mg kg⁻¹ total mercury (mean 0.32 mg kg⁻¹), while the Nowra snapper ranged from 0.01 to 0.78 mg kg⁻¹ total Hg (mean 0.11 mg kg⁻¹). These latter results appear anomalously low relative to other studies in Australia and New Zealand.

Methyl mercury averaged 94.7% of the total mercury content of the Sydney snapper, and 91.3% for the Nowra snapper.

The concentrations of selenium in the muscle tissues of snapper from both areas were similar and did not increase with increasing mercury concentrations. The highest selenium concentration was 0.85 mg kg⁻¹.     

Distribution of cadmium,mercury, and lead in different body parts of Baltic herring (Clupea harengus) and perch (Perca fluviatilis): Implications for environmental status assessments

For heavy metals, quality standards indicating good environmental status are designed to evaluate concentrations in the whole fish body, whereas monitoring of metals is often conducted using muscle or liver tissue. As most metals accumulate at different rates in different parts of fish, data should be adjusted to reflect whole fish body concentrations; however, this requires knowledge on distribution of metal concentrations within fish. Here, concentrations of cadmium, mercury, and lead were analyzed in the liver, muscle and whole fish of herring and perch to create conversion factors for transformation of heavy metal concentrations between these tissues. Species-specific accumulation of metals between muscle, liver, and whole fish were observed. Relationships between different tissues were used to recalculate data from monitoring programs in the Baltic Sea region. Based on whole fish concentrations, environmental status for cadmium and mercury in herring improved compared to assessments based on muscle or liver concentrations alone.     

Esterases activities and lipid peroxidation levels in muscle tissue of the shanny Lipophrys pholis along several sites from the Portuguese Coast

This study is part of a project aiming to validate the use of the intertidal shanny Lipophorys pholis as a sentinel species in pollution monitoring in NW European marine ecosystems. To this end, a characterisation of acethylcholin (AChE), butyrylcholin (BChE) and propionylcholin (PrChE) esterases in L. pholis muscle was performed and the results indicated that AChE was predominant. Furthermore, the use of eserine sulphate and BW284c51 (0.64–800 μM), and iso-OMPA (0.08–16 mM), confirmed the measurement of true cholinesterases (ChEs) as well as the presence of pseudocholinesterases. The field application of these markers to L. pholis, sampled in seven locations along the Portuguese coast, revealed that fish were likely to be affected by neurotoxic compounds. This was indicated by the significant depletion of AChE (p < 0.05) in animals collected at urban and industrialised sites, compared with those from reference locations. The inclusion of a marker of effect, measured as lipid peroxidation levels in muscle tissue, also revealed the existence of site differences. Overall, the study further validates the utility of L. pholis in pollution monitoring studies.     

Zinc in Fish, Crabs, Oysters, and Mangrove Flora and Fauna from Cleveland Bay

Zinc in muscle tissue from 28 species of fish, three species of sharks and rays, two species of squid and cuttlefish, and three species of crustacea collected from Cleveland Bay, together with some measurements made on oysters and mangrove flora and fauna are reported. In the fish species the mean Zn concentration in muscle tissue was 4.83 ± 2.82 μg/g wet weight, slightly lower than zinc measurements (7 μg/g wet weight) made in 14 fish species collected from the bay in 1975. Zinc in sharks and rays ranged from 3.5 to 7.2 μg/g wet wt, in squid and cuttlefish 13–16 μg/g wet wt, and in crustacea levels ranged from 14 to 18 μg/g wet wt. Zinc levels in fish varied between species with concentrations well below the ANZECC Maximum Residue Limit of zinc in seafood (150 μg/g wet wt). Although lower zinc concentrations were found in oysters collected from the Townsville Harbour area (2080 μg/g wet wt), compared with previous measurements made 25 years ago at this site, these levels are still above the Maximum Residue Limit for zinc in oysters (1000 μg/g wet wt). Concentrations of zinc in oysters from Orpheus Island (2547 μg/g wet wt), about 74 km away from industrial and urban activity, are also above the safe guideline values. Horseshoe Bay oysters transplanted to Ross Creek accumulated zinc at a rate of about 100 μg/g of oyster tissue per week, suggesting that dissolved zinc levels at this site are elevated, and that oysters rapidly accumulate zinc. Highest concentrations of zinc in mangrove leaves (30–65 μg/g dry wt) occurred in Osbornia octodonta, Exocaria agalocha, and Aegialitus annulata, compared with Ceriops tagal, and Avicennia marina (5–10 μg/g dry wt). No significant difference in zinc concentration occurred between leaves and litter fall for most of these species, with the sole exception of Exocaria, which showed almost a twofold increase in concentration. In seven species of mangrove fauna levels of zinc were very uniform and close to 50 μg/g (dry wt) Telescopium telescopium from the mouth of the Ross Estuary was the exception with levels at 400 μg/g (dry wt).     

Accumulation of butyltins in muscle tissue of chinook salmon reared in sea pens treated with tri-n-butyltin

Muscle tissue of chinook salmon, Oncorhyncus tshawytscha, reared for 3 to 19 months in sea pens treated with an antifouling biocide, tri-n-butyltin (TBT), contained organotin concentrations of 0.28–0.90 μg g⁻¹ (as TBT). Organotins are present in some pen-reared salmon sold in the United States: eleven of 15 salmon advertised as aquaculture products and purchased from public markets contained organotin concentrations of 0.081–0.20 μg g⁻¹. Most common cooking practices do not effectively destroy or remove butyltins from salmon muscle tissue. We believe this is the first evidence of entry of organotins into the human diet in the United States.     

Physiological Responses of Five Seagrass Species to Trace Metals

Trace metal run-off associated with urban and industrial development poses potential threats to seagrasses in adjacent coastal ecosystems. Seagrass from the largest urban (Moreton Bay) and industrial (Port Curtis) coastal regions in Queensland, Australia were assessed for metal concentrations of iron (Fe), aluminium (Al), zinc (Zn), chromium (Cr) and copper (Cu). Trace metal concentrations in seagrass (Zostera capricorni) leaf and root-rhizome tissue had the following overall trend: [Fe] > [Al] > [Zn] > [Cr] > [Cu]. Rainfall events and anthropogenic disturbances appeared to influence metal concentrations in seagrasses with the exception of Al, which does not appear to bioaccumulate. In laboratory experiments, five seagrass species (Halophila ovalis, H. spinulosa, Halodule uninervis, Z. capricorni, Cymodocea serrulata) were incubated with iron (1 mg Fe l⁻¹) and copper (1 mg Cu l⁻¹) and responses assessed by changes in PSII photochemical efficiency (Fv/Fm), free amino acid content and leaf/root-rhizome metal accumulation. Iron addition experiments only affected Halophila spp, while copper additions affected other seagrass species as well. Trace metal contamination of seagrasses could have ramifications for associated trophic assemblages through metal transfer and seagrass loss. The use of photosystem II photochemical efficiency as well as amino acid concentrations and composition proved to be useful sublethal indicators of trace metal toxicity in seagrasses.     

Total and methylmercury residues in cartilaginous fish from Mediterranean Sea

Concentrations of mercury and methylmercury residues were determined in the muscle tissue of three cartilaginous fishes Chimaera monstrosa (ghostshark), Torpedo nobiliana (electric ray) and Myliobatis aquila (eagle ray) from the Mediterranean Sea. The highest mean levels of total mercury were detected in ghostshark (3.14 mg/kg wet weight), followed by electric ray (2.42 mg/kg wet weight), and eagle ray (0.83 mg/kg wet weight). Such a variability is influenced by quite a number of factors, among which size, fish ecology and feeding habits. The percentages of the methylated form to total mercury ranged from a minimum of 72% in eagle ray to a maximum of 83% in ghostshark. Relationship between specimen size and mercury and methylmercury concentrations were found in ghostshark species.     

Imposex in Morula Granulata as Bioindicator of Tributyltin (TBT) Contamination in the Dampier Archipelago, Western Australia

This study was undertaken to examine the use of imposex in the tropical neogastropod whelk Morula granulata as bioindicator of tributyltin (TBT) contamination. Samples were collected from sites throughout the Dampier Archipelago; both impact sites close to intensive shipping activity and remote control sites. TBT in this area originates mainly from commercial vessels using the Port of Dampier that are >25 m in length and exempt from legislation controlling the use of TBT in antifouling paints. A field survey was undertaken in July 1997; 100 M. granulata were taken at each of 18 sites with varying vessel activity, and examined for imposex. The level of TBT contamination in the Archipelago was low; ranging from <0.3 to 25 ng Sn l⁻¹ in water,<0.3 to 80 ng Sn g−¹ in oyster tissue (Saccostrea cuccullata – prey of M. granulata), and <0.3 to 33 ng Sn g⁻¹ in whelks. Percentage of imposex in M. granulata ranged from 0% to 57%, and was correlated with distance to vessel activity (r=0.646, p<0.05). The only significant relationship of imposex with butyltin concentrations was with TBT in oysters (r=0.826, p<0.05), and dibutyltin (DBT) in whelks (r=0.783, p<0.05). It is postulated that this is because of interspecies variation in ability to metabolize TBT to DBT and MBT (monobutyltin), as well as induction of imposex in earlier life stages, so that imposex in adults could be a reflection of prior contamination. M. granulata is a suitable bioindicator of TBT contamination in the Dampier Archipelago, which could be used throughout the Indo-Pacific given its abundance in the region.     

Mercury,organic-mercury and selenium in small cetaceans in Taiwanese waters

Total Hg (∑Hg), organic-Hg (O-Hg) and Se bioaccumulations in small cetaceans distributed in Taiwanese waters of the Taiwan Strait and the southwestern Pacific have been investigated for the first time. The results could represent the baseline metal concentrations of marine mammals in the southwestern Pacific, where volcanic activities are possibly the major source of mercury to the environments. Muscle samples of four species of small cetaceans were collected from animals accidentally caught by tuna-longline fisheries from 1994 through 1995. In total, 53 pantropical spotted dolphins, Stenella attenuata, nine spinner dolphins, S. longirostris, five bottlenose dolphins, Turiops truncatus and four Risso's dolphins, Grampus giseus were analyzed. In addition, two stranded pantropical spotted dolphins were investigated. Cold vapour AAS and ICP-MS were used in the analysis of Hg and Se, respectively. Significant species difference was found in the four species of small cetaceans. Among them, the pantropical spotted dolphin showed the highest mean concentration (mg/kg wet wt.) of both ∑Hg (3.64±2.19) and O-Hg (2.79±1.23), whereas the Risso's dolphin had the highest mean concentrations of Se (1.77±1.29). There was no significant sex difference with respect to metal bioaccumulation in the samples of S. attenuata. Significant correlations between body length (BL) and ∑Hg, as well as O-Hg concentrations were observed in pantropical spotted (Sa) and spinner dolphins (Sl). The linear relationships were Sa: ∑Hg=−8.290+0.066BL, r=0.421; Sl: ∑Hg=−2.735+0.025BL, r=0.875; Sa: O-Hg=−3.723+0.036BL, r=0.408; and Sl: O-Hg=−3.017+0.025BL, r=0.870. However, a demethylation phenomenon that decreasing the percentage of O-Hg coupled with increasing levels of Se was observed when the ∑Hg concentrations in the muscle tissues of dolphins reached 4 mg/kg wet wt.     

Composition and distribution of organochlorine pesticide residues in surface sediments from the Wu-Shi River Estuary,Taiwan

The contamination of organochlorine pesticides (OCPs) in sediments from the Wu-Shi River estuary was investigated to evaluate the pollution potentials and distribution of OCPs in central Taiwan. A total of 19 sediment samples were collected at five sampling stations along the River estuary. The concentrations of OCPs were in the range of 0.99–14.5 ng/g-dry weight (dw) for ΣHCH (-, β-, γ-, δ-HCH), 0.46–13.4 ng/g-dw for Σcyclodiene and 0.53–11.4 ng/g-dw for ΣDDT (p,p^′-DDD, p,p^′-DDE, p,p^′-DDT). The mean concentrations of ΣHCH, Σcyclodiene and ΣDDT were 3.79, 4.87 and 2.51 ng/g-dw, respectively. The total concentrations of OCPs correspond to 1.73–71.9 μg/g-OC when normalized to TOC contents. Among the organochlorine pesticides, endosulfan sulfate, β-HCH, and p,p^′-DDD were the most dominant compounds in the sediments with the average concentrations of 1.97, 3.43 and 2.08 ng/g, respectively. Also, different contamination patterns among sampling seasons were observed. The measured concentrations of OCPs collected in spring were higher than those in autumn and winter. A linear relationship between sediment characteristics and OCP residues was also demonstrated. The results obtained in this study show that there still exist a variety of organochlorine pesticide residues in the sediments from the near shore of central Taiwan.     

Chlorinated hydrocarbons in marine fish and shellfish of Nigeria

The concentration ranges of chlorinated hydrocarbons in marine fish were HCB (0.03–9.5 ppb), Lindane (0.02–5.3 ppb), Endosulphan (0.21–4.9 ppb), DDT (0.50–18.6 ppb), Aldrin (0.05–54.6 ppb) and PCB (4.78–225 ppb). Fish contained higher concentrations of Aldrin, Heptachlor, HCB and Lindane than shellfish, while a reverse trend was observed for DDT and PCBs. The concentrations of residues obtained were found to be lower than those reported in literature for industrialized countries. Predator fish species were found to concentrate more residues in muscle tissue than plankton feeders. The DDT/PCB values were less than 1 indicating a predominance of industrial activities over agricultural activities as the source of contamination of the marine environment. The fish Galeoides decadactylus is a potential bio-indicator for chlorinated hydrocarbons pollution monitoring in the study area.     

Esterase activities and lipid peroxidation levels in offshore commercial species of the NW Mediterranean Sea

There is a lack of information on monitoring neurotoxicity in offshore commercial species. To help fill this gap, we sampled hake (Merluccius merluccius) and Norway lobster (Nephrops norvegicus) in fishing grounds off the coast of l’Ametlla de Mar (NW Mediterranean) in June 2005 at a depth of 100 m and 400 m. Additionally, at 400 m depth, two other fish species, Micromesistius poutassou and Phycis blennoides were included. Neurotoxicity markers such as Colinesterases (ChEs), namely acethyl- (AChE), butyryl- (BChE), propionyl- (PrChE) and carboxilesterase (CbE) were measured in muscle. Lipid peroxidation (LP), a marker of oxidative damage, was also included. The results are discussed in relation to the animal’s sex, size and fishing depth. A comparison of esterases and LP levels between muscle and liver of hake and between muscle and hepatopancreas of Norway Lobster was made.

AChE was dominant in muscle and CbE in hepatopancreas. No differences between fish species were seen for AChE. However, N. norvegicus, presented lower levels of ChEs and LP. A size-dependence in ChEs was seen for M. merluccius, with larger animals showing significantly lower activities (p < 0.05). Sex-dependence was seen in N. norvegicus for most esterases, except AChE, with males displaying higher activities (p < 0.05). A sampling-depth effect was also seen in the crustacea, with animals from 100 m generally presenting lower esterase activities and higher LP levels.     

The ground-state conductivity profile of the core-mantle system of the Earth

The ground state of the core-mantle conductivity system is defined as a step function transition from the constant non-zero conductivity of the core to zero conductivity in the mantle. This ground state is reached by letting the thickness of a transition region Δ → 0, where Δ appears as a parameter in the model conductivity of the system. By a transformation of the equation governing the behavior of the electrostatic potential φ, it is shown that the function V(x) = (1/σ^1/2)(d²σ^1/2/dx²) acts as a potential barrier in the quantum mechanical sense, and that for certain conductivity profiles σ(x), where x is the usual Cartesian coordinate, the electrostatic potential is screened out in regions where σ(x) → 0 as Δ → 0. Consequently, E = −φ also vanishes in these regions. The results generalize to the time-dependent case. Conditions that the conductivity function σ(x) must satisfy to qualify as the ground-state conductivity are defined and an example is provided.     

Contamination by Persistent Organochlorines in Small Cetaceans from Hong Kong Coastal Waters

Blubber samples of 2 cetacean species, the Indo-Pacific hump-backed dolphin (Sousa chinensis) (n=11) and finless porpoise (Neophocaena phocaenoides) (n=9), collected from Hong Kong coastal waters were analysed for persistent organochlorines. Mean concentration in the blubber of DDTs was ranked first (46 μg/g wet wt.), followed by PCBs (24 μg/g wet wt.), HCHs (0.76 μg/g wet wt.), chlordane compounds (0.38 μg/g wet wt.) and HCB (0.07 μg/g wet wt.). The present cetacean species may potentially be faced with high risk due to the elevated level of DDTs and PCBs. Relatively high concentrations of PCBs and DDTs can be attributed to the continuous environmental input of these compounds in the Far East region including Hong Kong. Highly chlorinated PCBs such as IUPAC Nos. 138, 153, 180 were the prominent congeners, accounting for 39% of the total PCBs. Mean concentrations of 6 non- and mono-ortho coplanar congeners were 2.1 and 2.8 μg/g wet wt. in the hump-backed dolphin and finless porpoise, respectively. Among highly toxic coplanar PCBs, mono-ortho congener IUPAC No. 118 and non-ortho congener IUPAC No. 126 were estimated to have the greatest toxicity contribution. Tris(4-chlorophenyl) methane (TCPMe) and tris(4-chlorophenyl) methanol (TCPMeOH), which have been the most recently identified microcontaminants, were also detected with the highest concentration of 290 and 300 ng/g (wet wt. basis), respectively. The concentrations of TCPMe relative to TCPMeOH in cetaceans from Hong Kong coastal waters were significantly higher than those found in various seals collected from other parts of the world, suggesting the different metabolic system of these two compounds between seals and cetaceans. Correlations between the concentrations of tris-chlorophenyl compounds with other persistent organochlorines such as HCHs, CHLs, DDTs and PCBs were significant, suggesting their accumulation nature similar to these organochlorines.     

Profiles of Fecal Porphyrins in River Otters Following the Exxon Valdez Oil Spill

Median levels of Coproporphyrin III (Copro III) in fecal samples of river otters (Lontra canadensis) collected from an oiled area in Prince William Sound, Alaska, USA, during 1990 were significantly higher than in samples collected from the same oiled area during 1996 (p=0.011, one way analysis of variance), a nonoiled reference area in Prince William Sound during 1996 (p=0.002) and a reference area in southeast Alaska during 1998 (p=0.004). An overall test of significance that combined probabilities from the statistical analysis of this porphyrin study with those from other biomarker studies revealed a significant difference in physiological response of river otters between oiled and nonoiled areas of the Sound for 1990 (p < 0.01). We demonstrated that changes in levels of fecal porphyrins may serve as a biomarker that may contribute to a health assessment of wild river otters.     

Distribution and abundance of Daphnia pulicaria, a large Daphnia of the “pulex group”, in Lake Constance (Lower Lake)

The population dynamics and distribution of Daphnia pulicaria were studied in Lake Constance (Lower Lake). This Daphnia was absent in the year 2004, absent during most part of the year 2005 and absent in spring 2007 but present from November 2005 to July 2006. Abundance was high from January to late May of the year 2006; maximum abundance was 95,000 ind. m⁻² (30 May). Males and ephippial females were observed in January and late May. Ovigerous females constituted between 30% and 70% of adult females from November 2005 to April 2006; in June and July their percentage decreased to <20%. Mean number of eggs per egg-bearing female ranged between 2 (in November 2005) and 9.8 (in April 2006) and maximum egg number was 20. Birth and growth rates were low (generally <0.15); death rate was highest in June (0.275). Females of D. pulicaria were larger than females of Daphnia galeata/hyalina but carried somewhat fewer eggs. D. pulicaria generally preferred the deep cool water layers. The species was abundant in the northern parts of the Lower Lake (Gnadensee and Zeller See), rare in the southern parts (Rheinsee) and absent in the Upper Lake. We conclude that the life history and occurrence of large-bodied D. pulicaria in Lake Constance can be governed by fish predation pressure. This suggestion is supported by analyses of stomach contents from Coregonus lavaretus; stomachs contained high proportions of D. pulicaria in the first half of the year 2006. The disappearance of D. pulicaria in early summer and the comparatively low proportion of adults for most part of the investigation period also indicate that fish predation is involved in the dynamics of this Daphnia. The preference for deep cool water can be strategy to reduce predation risk. The low density of D. pulicaria in the southern basin of Lower Lake (Rheinsee) may be explained by the influence of the Rhine River which flows through this basin.