Significance and interspecific variability of accumulated trace metal concentrations in Antarctic benthic polychaetes.

Trace metals were analysed in polychaetes collected on Polarstern cruise ANT XXI/2 (2003/04) to the Weddell Sea. Pb concentrations were largely less than 1.3 mg kg(-1)DW in all samples analysed. Statistical results indicate that the accumulated Cd, Cu and Zn concentrations are related to the feeding guild to which the animals are belonging. Relatively low Cd and Cu concentrations are found in macrophagous carnivores and relatively high concentrations in microphagous detritus feeders. The relationship between Zn concentrations and the feeding guilds of polychaetes is reverse. Cd concentrations range from (median values and interquantile ranges in brackets) 2.6 (1.5-3.2) mg kg(-1)DW in the carnivorous Trypanosyllis gigantea to 133 (37-176) mg kg(-1) in the microphagous detritus feeder Lanicides bilobata; Cu concentrations from 16 (11-19) mg kg(-1) in the carnivorous Antarctinoe spicoides to 40 (23-68) mg kg(-1) in the microphagous detritus feeder Phyllocomus crocea and Zn from 89 (69-97) mg kg(-1) in the microphagous detritus feeder Isocirrus yungi to 396 (372-404) mg kg(-1) in the carnivorous Aglaophamus trissophyllus. Ni is ranging from 3.7 (1.8-6.0) mg kg(-1) in Polyeunoa laevis to 34 (20-41) mg kg(-1) in A. spicoides, but no significant differences are obvious regarding the feeding guilds. Since information on metals in Antarctic polychaetes is almost completely lacking, our results suggest further studies to clarify the role of feeding in the bioaccumulation of metals in this ecologically important taxonomic group.

Bioaccumulation of trace metals in the brown shrimp Crangon crangon (Linnaeus, 1758) from the German Wadden Sea.

The objective of the present study is to evaluate the suitability of the brown shrimp Crangon crangon (Linnaeus, 1758) from the German Wadden Sea as a biomonitor for the trace metals Cd, Pb, Cu, and Zn and to analyse whether the two-compartment model sensu OECD could be used as a predictive tool to assess environmental quality. The tested decapods accumulated Cd and Pb upon exposure and it was possible to estimate significant model parameters of two-compartment models, while they did not respond to waterborn Cu and Zn. Kinetic BCFs at theoretical equilibrium were 860 for Cd and 750 for Pb. A tentative estimation showed the following sensitivity of C. crangon to an increase of soluble metal exposure: 0.4 microg Cd l(-1) and 0.9 microg Pb l(-1). Available information can be used to quantify a measure of agreement or disagreement between bioaccumulation in various decapods. This can be regarded as an important step in the calibration of biomonitors, which is necessary to assess the potential for bioaccumulation on different temporal and geographical scales.

Trace metal concentrations in Antarctic sea spiders (Pycnogonida, Pantopoda).

Trace metals were analysed in sea spiders collected on two Polarstern cruises in the Weddell Sea. We found a substantial interspecific heterogeneity of Cd, Cu, Ni, and Zn, indicating varying accumulation strategies and metabolic demands for essential elements. Means and 95%-confidence intervals for all 44 samples analysed are 26+/-7 mg Cd kg(-1), 38+/-22 mg Cu kg(-1), 62+/-13 mg Ni kg(-1) and 990+/-130 mg Zn kg(-1) DW. Only for Pb do we find values less than 1.0 mg kg(-1) for most collectives analysed, in good agreement with other Antarctic arthropods such as crustaceans. Our study provides further evidence for the frequently reported "Cd anomaly" in many polar arthropods. While Cu concentrations in pantopods are within the reported range for Antarctic amphipods and decapods, Ni concentrations are exceptionally high and might be part of predation defence mechanisms. These possibilities should be investigated in more detail in future studies.

Heavy metals in zooplankton and decapod crustaceans from the Barents Sea.

Trace metals (Cd, Cu, Pb and Zn) were analysed in zooplankton samples and decapod crustaceans collected on cruises of "RV Walther Herwig III" to the Barents Sea (Summer 1991, 1994 and 2000). We found a substantial spatial heterogeneity in the decapod crustacean Pandalus borealis, with increasing Cd concentrations from the south (North Cape Bank; 0.7 mg kg(-1) DW) to the north (north of Svalbard; 4.7 mg kg(-1)), supporting the hypothesis that the frequently reported Cd-anomaly in polar crustaceans might be extended to the Barents Sea. Regarding various crustaceans and zooplankton collectives (2000) a distinct interspecific heterogeneity of metals was obvious, with lowest Cd concentrations in euphausiids and chaetognaths and highest ones in decapods and hyperiid amphipods; lowest Cu concentrations in chaetognaths and copepods and highest ones in euphausiids and decapods; and lowest Zn concentrations in euphausiids and decapods and highest ones in some copepods. For Pb many values were below or close to the limit of detection, suggesting that Pb concentrations about 0.4 mg kg(-1) might serve as a regional background value. Results for Cd, Cu and Zn in copepods of this study are largely within the reported range, but high Cd concentrations in copepods from summer in contrast to reported lower ones during winter/spring may be related either to changing accumulation strategies of the copepod species involved or to seasonally changing Cd absorption in copepods from food.

Assessment of two-compartment models as predictive tools for the bioaccumulation of trace metals in the amphipod Gammarus oceanicus Segerstråle, 1947 from Grunnfjord (Northern Norway).

The objective of the present study is to evaluate the suitability of the eulittoral gammaridean amphipod Gammarus oceanicus Segerstråle, 1947 from Grunnfjord (Northern Norway) as a biomonitor for trace metals Cd, Cr, Pb, Cu, Ni and Zn and to analyse whether the two-compartment model could be used as a predictive tool to assess environmental quality. The focus here is on the adjustment of this model to situations where a linear extrapolation of accumulated metals to increasing external metal exposures is not applicable. The amphipods tested accumulated metals upon exposure and it was possible to estimate significant model parameters of two-compartment models, with the sole exception of Zn. These could be used to predict accumulation of Cd, Cr and Pb in a concentration-dependent uptake study, for Cr directly and regarding simultaneous parameter estimation, for Cd and Pb after adjustment taking into account a non-linear relationship between bioconcentration factors (BCFs) and external metal exposures. The elements Cu and Ni need further evaluation, since linear predictions from the two-compartment models were not applicable, whilst a relationship between kinetic parameters and metal exposures could not be established. Kinetic BCFs at theoretical equilibrium were 80-202 for Cd, 80-112 for Cr, 306 for Cu, 251-520 for Pb and 23 for Ni. A tentative estimation showed the following sequence of sensitivity of G. oceanicus to an increase of soluble metal exposure: 0.6 microg Cdl(-1), 0.8 microg Pbl(-1), 2.5-2.9 microg Crl(-1), 8.5 microg Cul(-1) and 11 microg Nil(-1). Available information can be used to quantify a measure of agreement or disagreement between bioaccumulation in different amphipods. This can be regarded as an important step in the calibration of biomonitors, which is necessary to assess the potential for bioaccumulation on a large geographical scale.

Bioaccumulation of trace metals in the amphipod Chaetogammarus marinus (Leach, 1815) from the Avon and Tamar estuaries (UK): comparison of two-compartment and hyperbolic toxicokinetic models.

Bioaccumulation of Cd, Cr, Cu, Co, Pb, Ni and Zn was investigated in the eulittoral gammaridean amphipod Chaetogammarus marinus (Leach, 1815) from the Avon and Tamar estuaries (UK). The main goals were to provide information on accumulation strategies of the organisms tested and to verify toxicokinetic models as a predictive tool. The organisms accumulated metals upon exposure and it was possible to estimate significant model parameters of two-compartment and hyperbolic models, with the exception of Zn. Both types of models yielded significant model estimates in two independent toxicokinetic studies using gammarids from the Avon and Tamar estuaries, respectively. Kinetic BCFs at theoretical equilibrium were 58-102 for Cd, 95-215 for Cr, 400-963 for Cu, 38-59 for Co, 150-750 for Pb and 33-63 for Ni, and were in most cases distinctly lower than the range reported in the literature for other amphipods. To demonstrate the potential of toxicokinetic models as a predictive tool, attempts were made, further to verify time-dependent model data (Tamar) with independent experimental data (Avon). In this case only for Cd were both in good agreement, whilst for all other elements the models overestimated the measured values. The second approach was to verify time-dependent model data (Tamar) with measured values from an independent concentration-dependent uptake study (Tamar) or, alternatively, to estimate the model parameters simultaneously for both studies. A good agreement between observed and predicted values was obtained for all elements for the simultaneous two-compartment models. Only for Cd was a simultaneous estimation of the hyperbolic model more promising. A tentative estimation showed the following sequence of sensitivity of C. marinus to an increase of soluble metal exposure: 0.6 microg Cd l(-1), 1.7 microg Cr l(-1), 16 microg Cu l(-1), 3.5 microg Co l(-1), 0.8 microg Pb l(-1) and 7 microg Ni l(-1). Available information can be used to quantify a measure of agreement or disagreement between bioaccumulation in different amphipods. This can be regarded as an important step in the calibration of biomonitors which is necessary to assess the potential for bioaccumulation on a large geographical scale.

Bioaccumulation of trace metals in the Antarctic amphipod Paramoera walkeri (Stebbing, 1906): comparison of two-compartment and hyperbolic toxicokinetic models.

Bioaccumulation of Cd, Pb, Cu and Zn in the Antarctic gammaridean amphipod Paramoera walkeri (Stebbing, 1906) was investigated at Casey station (Australian Antarctic Territory). The main goals were to provide information on accumulation strategies of the organisms tested and to verify toxicokinetic models as a predictive tool. The organisms accumulated metals upon exposure and it was possible to estimate significant model parameters of two-compartment and hyperbolic models. These models were successfully verified in a second toxicokinetic study. However, the application of hyperbolic models appears to be more promising as a predictive tool for metals in amphipods compared to compartment models, which have failed to adequately predict metal accumulation in experiments with increasing external exposures in previous studies. The following kinetic bioconcentration factors (BCFs) for the theoretical equilibrium were determined: 150-630 (Cd), 1600-7000 (Pb), 1700-3800 (Cu) and 670-2400 (Zn). We find decreasing BCFs with increasing external metal dosing but similar results for treatments with and without natural UV radiation and for the combined effect of different exposure regimes (single versus multiple metal exposure) and/or the amphipod collective involved (Beall versus Denison Island). A tentative estimation showed the following sequence of sensitivity of P. walkeri to an increase of soluble metal exposure: 0.2-3.0 microg Cd l(-1), 0.12-0.25 microg Pb l(-1), 0.9-3.0 microg Cu l(-1) and 9-26 microg Zn l(-1). Thus, the amphipod investigated proved to be more sensitive as biomonitor compared to gammarids from German coastal waters (with the exception of Cd) and to copepods from the Weddell Sea inferred from literature data.

Heavy metals of inshore benthic invertebrates from the Barents Sea.

To assess metals in biota of the Barents Sea, information is presented on concentrations of Cu, Cd, Ni, Pb and Zn in the marine inshore benthic invertebrates Gammarus oceanicus, Littorina rudis, Nucella lapillus, Mytilus edulis and Arenicola marina collected in summer 1994. For geographical comparisons, the metal content to body size relationship was taken into account due to the different body sizes found at the localities investigated. In general, our data provide further evidence for the cadmium anomaly in invertebrates from polar waters which has been frequently discussed in the literature, with Cd concentrations reaching 1 mg x kg(-1) dry wt in G. oceanicus, 7 mg x kg(-1) in L. rudis and 24 mg x kg(-1) in N. lapillus. In contrast, our results obtained for Cd in M. edulis and A. marina are largely within a world-wide reported range (1-2 and 0.2-0.9 mg x kg(-1), respectively). Although some severe Ni emissions in the Kola region (Russia) mainly from nickel smelters have been reported, we do not find indications of an enhanced Ni availability in the marine biota studied compared to other areas

Bioaccumulation of trace metals in the Antarctic amphipod Orchomene plebs: evaluation of toxicokinetic models.

Bioaccumulation of Cd, Co, Cu, Ni, Pb and Zn in Antarctic gammaridean amphipod collectives, Orchomene plebs (Hurley, 1965), was investigated during a cruise of RV "Polarstern" to the Wedell Sea. With the sole exception of Cd the organisms accumulated metals during exposure and depurated them in uncontaminated seawater. Four independent toxicokinetic experiments and one field study were modelled simultaneously to calculate the following size-dependent bioconcentration factors for organisms with body length 10 mm (BCF(10 mm)): 130 (Co), 4030 (Cu), 190 (Ni), 2900 (Pb), and 5210 (Zn). On the time scale of our experiments the data suggest an increased metal uptake by previously exposed test organisms. The collectives investigated may be regarded as potentially suitable biomonitors for Co, Cu, Ni, Pb and Zn but not for Cd. An approach to evaluate the sensitivity of Orchomene plebs as a biomonitor of waterborne metals in the field indicates minimal increments of the ambient exposure concentrations of 0.01 microg Co l(-1), 0.2 microg Cu l(-1), 0.4 microg Ni l(-1), 0.6 microg Pb l(-1) and 0.3 microg Zn l(-1).

Trace metals in Antarctic copepods from the Weddell Sea (Antarctica).

The concentrations of Cd, Co, Cu, Ni, Pb and Zn were determined in the Antarctic copepods Rhincalanus gigas (Brady, 1883), Calanus propinquus (Brady, 1883), Calanoides acutus (Giesbrecht, 1902), Metridia curticauda (Giesbrecht, 1889) and Metridia gerlachei (Giesbrecht, 1902). Samples were taken at seven different stations between 18.01.1999 and 19.02.1999. Metal concentrations in biological tissue were determined by graphite furnace atomic absorption spectroscopy (GFAAS) with Zeeman background correction and by flame AAS (air-acetylene) with deuterium background correction. We found high mean Cd concentrations in the Metridia species of about 10 microg Cd g(-1) and 3-6 microg Cd g(-1) in the other copepods. Co and Pb concentrations were low in all species investigated (<0.1 microg Co g(-1) and <1 microg Pb g(-1)). Zn concentrations were high in M. gerlachei and R. gigas (518 and 430 microg Zn g(-1)). In comparison to copepods from Arctic Seas (Fram Strait, Greenland Sea) and the North Sea, Cd and Cu concentrations appear higher in Antarctic copepods, while Ni and Pb concentrations are similar in both polar regions and Pb concentrations are higher in the North Sea. Variability between species and different regions are discussed.

Bioaccumulation of trace metals in the calanoid copepod Metridia gerlachei from the Weddell Sea (Antarctica).

Bioaccumulation of Cd, Co, Cu, Ni, Pb and Zn in the Antarctic calanoid copepod Metridia gerlachei (Giesbrecht 1902) was investigated during a cruise of RV 'Polarstern' to the Weddell Sea, primarily to provide information on accumulation strategies for the metals tested. With the sole exception of Cd, the copepod accumulated metals during exposure and depurated them in uncontaminated seawater. The process of uptake and depuration was successfully described by a hyperbolic model, leading to significant estimations of the following experimental bioconcentration factors (BCFs): 210 (Co), 3430 (Cu), 3060 (Ni), 670 (Pb) and 2090 (Zn). Furthermore, we provide an approach to evaluate the sensitivity of Metridia gerlachei as a biomonitor of water-borne metals in the field; the results indicate minimal increments in ambient exposure concentrations of: 0.5 microg Cu l(-1), 0.8 microg Ni l(-1), 0.6 microg Pb l(-1) and 0.2 microg Zn l(-1), suggesting a high sensitivity of M. gerlachei for biomonitoring.

Bioaccumulation of trace metals in the copepod Calanoides acutus from the Weddell Sea (Antarctica): comparison of two-compartment and hyperbolic toxicokinetic models.

Bioaccumulation of Cd, Co, Cu, Ni, Pb and Zn in the Antarctic calanoid copepod Calanoides acutus (Giesbrecht, 1902) was investigated during a cruise of RV 'Polarstern' to the Weddell Sea. Main goals were to provide information on accumulation strategies of the organisms tested and to verify toxicokinetic models as a predictive tool. Except for Cd, the organisms accumulated metals upon exposure. It was possible to estimate significant model parameters of two-compartment and hyperbolic models. These models were successfully verified in a second toxicokinetic uptake study. The model verification was extended in a third uptake study with increasing external metal dosing. We found a linear increase of net uptake with external waterborne metal exposures up to 80 microg Pb l(-1), with excellent predictions of the two-compartment model. For Co both models give reasonable predictions up to 20 microg Co l(-1). Regarding Cu, Ni and Zn only hyperbolic model predictions were in good agreement with measured values up to 150 microg Cu l(-1), 80 microg Ni l(-1) and 290 microg Zn l(-1). Due to a decrease of Cd body burden in the experiments, only the hyperbolic model was applicable, leading to reliable predictions up to 20 microg Cd l(-1). These concentrations largely determine the range for which these models may serve as a predictive tool.

Heavy metals in fish from the Barents Sea (summer 1994).

To assess the significance of metals in biota of the Barents Sea, preliminary information is presented for the concentrations of Cd, Pb, Hg, Ni, Cu and Zn in liver and muscle tissues of 15 marine fish species collected in the summer of 1994. Lead and Ni concentrations are below limits of detection (< 0.3 and 1.0 mg kg-1 dry wt.) in all tissues, as is Cd in muscle (< 0.10 mg kg-1). Generally, most of our results are within the reported literature range for various Arctic marine systems, especially regarding some commercially important species like cod and redfish, indicating that metal levels are not elevated. However, the interspecific variability is substantial and some remarkably high Cd levels (2.4 and 8.1 mg kg-1 dry wt.) in livers of Anarhichas species (catfish) and Raja fyllae (round skate) point to the problem of a general 'cadmium-anomaly' in polar marine waters, previously inferred from reported results for various pelagic and benthic invertebrates.

Trace metals in field samples of zooplankton from the Fram Strait and the Greenland Sea.

Trace metals (Cd, Pb, Ni, Cu, Zn and Hg) were evaluated in 14 zooplankton taxa collected on cruise ARK IX/Ib of RV 'Polarstern' to the Fram Strait and the Greenland Sea in March and April 1993. We found a substantial interspecific heterogeneity, e.g. with rather low Cd concentrations in calanoid copepods (0.1-0.7 mg kg-1, dry wt.) but remarkably high levels in the decapod Hymenodora glacialis (7-9 mg kg-1) and in the amphipods Themisto abyssorum and T. libellula (24-34 kg-1). In general, Pb was low (< 1 mg kg-1), while some enhanced Ni concentrations were found in the ostracod Conchoecia borealis (66-86 mg kg-1). A comparison to world-wide reported data on marine crustaceans did not reveal any suggestions on increased metal availabilities in both areas investigated, although one might expect a transport of some metals from Siberian rivers across the pole by the Transpolar Ice Drift Stream. However, more information on accumulation strategies of zooplankton under winter and summer conditions is necessary before a full assessment of metals in Arctic waters will be possible.

Validation of estuarine gammarid collectives (Amphipoda: Crustacea) as biomonitors for cadmium in semi-controlled toxicokinetic flow-through experiments.

Concentrations of chemicals in organisms are regarded as being indicators of the bioavailable fraction of those substances in the environment. Three gammarid collectives (assemblages) from the Weser-estuary (NW Germany), showing different species compositions, were used as experimental units to evaluate their suitability as biomonitors. Uptake and clearance of cadmium was investigated in semi-controlled dynamic flow-through tests. Kinetic data obtained from two compartment models confirmed a net accumulation strategy of gammarids for Cd and resulted in similar bioconcentration factors (BCFs) within the same experimental treatments. Deviations in bioconcentration factors between two treatments (BCFs: 377-542 vs 947-1190, based on dry wt) obtained under similar exposures (17 +/- 2 and 23 +/- 2 microg Cd litre(-1)) could not be assigned to significant fluctuations of both Cd levels and particulate matter in the flow-through systems. The biological half-life of Cd in gammarids was 6 to 12 days. It is concluded that gammarid collectives of different species composition may be used as experimental units in biomonitoring studies. This conclusion was confirmed by homogeneous Cd concentrations in field samples of gammarids from the Weser-estuary (0.34 +/- 0.03 mg kg(-1) dry wt., mean +/- 95% confidence intervals, N = 58).

Kinetics of bioconcentration and clearance of 28 polychlorinated biphenyl congeners in zebrafish (Brachydanio rerio).

Bioconcentration experiments were performed on 28 polychlorinated biphenyl (PCB) congeners with NCl = 2 to NCl = 10, evaluating them simultaneously. Bioconcentration factors (BCFs) were calculated from the uptake rate constant (k1) and the clearance rate constant (k2) as BCF = k1/k2. BCFs on a wet weight basis ranged from 7710 to 940,000. They were correlated with octanol-water partition coefficients (P). The curvilinear relationship between log BCF and log P based upon data covering the log P range 5.06 to 8.18. About a log P of 7.38, a range of "optimal lipophilicity," results in highest BCFs for PCBs, above which the degree of bioconcentration decreases.

Kinetics of bioaccumulation and clearance of isomeric hexachlorocyclohexanes.

Bioaccumulation experiments were performed on the hexachlorocyclohexane isomers alpha-HCH, beta-HCH, gamma-HCH and delta-HCH, testing them simultaneously. Bioaccumulation factors (BCFs) were calculated from the uptake rate constant (k1) and the clearance rate constant (k2) as: BCF = k1/k2. The BCFs of alpha-HCH (1100 +/- 175) and gamma-HCH (920 +/- 131) were similar. The BCFs of beta-HCH (1520 +/- 276) and delta-HCH (1640 +/- 269), also similar, were significantly higher than those of the alpha- and gamma-isomers.