Description: Accurate congener-specific determination of chlorobiphenyl congeners (all 209 congeners) is finally possible with the use of multidimensional gas chromatography-electron-capture detection techniques. The effectiveness of this technique for environmental analyses is enhanced by ultraclean laboratory practices, non-destructive extraction and clean-up steps and the use of low-volume, high-efficiency HPLC separation for various classes of organic contaminants. In the light of these new developments conventional procedures for chlorobiphenyl analysis are evaluated.

Description: CO2 partial pressure in surface water was measured in the Northeast Atlantic and in the Hebride Shelf/North Sea area during a cruise with R.V. Poseidon in June 1991. A mean pCO2 of 303 μatm was found in the Atlantic between 50°N and 60°N. For an atmospheric CO2 content of 357.5 ppm(v) this corresponds to a partial pressure difference of −55 μatm. This supports the view that the subarctic Atlantic is a significant sink within the CO2 cycle between the ocean and the atmosphere. A comparison of our measurements with other data reveals that the pCO2 distribution changes significantly during May/June. This explained by seasonal warming, CO2 exchange with the atmosphere and biomass production. The contribution by each of these processes to the seasonal variations is calculated. It was found that during a plankton bloom the production of biomass is the dominating factor and may lower seawater pCO2 by almost 100 μatm. The shelf areas are charactrized by strong pCO2 gradients which are explained by water exchange with the Atlantic, temperature effects and biomass production.

Description: Concentrations of 23 individual chlorobiphenyls (CBs) and 6 polyaromatic hydrocarbons (PAHs) were determined in different water masses of the North Atlantic Ocean around Iceland. The study was carried out in the framework of the second Intergovernmental Oceanographic Commission (IOC) baseline studies of contaminants in the North Atlantic Ocean, involving trace organics and trace elements. Concentrations of individual CBs were extremely low. In solution, they varied between 〈2 and 126 fg dm−3 and in suspension between 〈2 and 1400 fg dm−3. The values for their sum (∑CB) were between 10 and 1048 in solution, and 286–11 241 fg dm−3 in suspension. ∑PAHs were present in the 〈5–65 pg dm−3 range, p,p′-DDE and hexachlorobenzene were 〈2 fg dm−3. The concentrations of CBs and PAHs decreased from the surface towards the bottom at each station. The lowest concentrations were found in Norwegian Sea Deep Water (∑CB 10 fg dm−3), concurrent with the lowest halocarbon concentrations found during the cruise. Values in near-surface waters were considerably lower than those determined at mid-latitudes of the North Atlantic. These findings reflect the mixing of water bodies with higher CB concentrations from the central North Atlantic with less contaminated waters from the Arctic Ocean. Concentrations in suspension exceeded those in solution in most samples, as a result of the relatively high suspended matter concentrations in the waters around Iceland. Particulate CB and PAH concentrations were positively correlated with particulate organic carbon concentrations. This suggests that suspended organic material is a carrier for these relatively apolar organic compounds in the water column. The data do not support the co-distillation concept suggested in the literature.

Description: The effect of the supply of chlorinated biphenyls by the river Oder into some adjacent areas of Baltic Sea was studied in nine sediment cores and in 10 suspended matter samples. Congener-specific analysis was carried out on 28 individual chlorobiphenyls (CBs). ∑CB concentrations in suspension ranged from 2.4 pg dm-3 in the southern Bornholm Basin to 986 pg dm-3 in the Achterwasser. ∑CB contents in surface sediment decreased with increasing distance from the river mouth. Highest contents were found in the Oderhaff (18 ng g-1 dw) decreasing to 2 ng g-1 dw in the Bornholm Basin. The ∑CB contents generally decreased more or less regularly with increasing depth. The compositions of the CB mixtures in surficial sediment and suspension samples were rather similar, suggesting a common source. Compositions of the CB mixtures in the sediment cores showed distinct differences. These may reflect variations in source strength over time. Mass balance considerations on the basis of the 28 CBs resulted in an estimation of a total storage of approximate 733±158 kg ∑CBs in the Oderhaff, Achterwasser, Greifswalder Bodden, Oder Rinne, Arkona Basin and Bornholm Basin in the past 65 years, covering the time period since CBs were first produced. Based on river data about 500 kg of ∑CBs were supplied during this time by river Oder, that may thus be the major source of these compounds for the southern Baltic Sea.

Description: Metabolism of chlorobiphenyls (CBs) was studied in harbour porpoise by comparing patterns of CB-X/CB-153 ratios in blood, brain, liver and blubber with the patterns in herring, the main food source. The CBs were classified in five groups, based on the presence/absence of vicinal H-atoms (vic. Hs) in meta,para (m,p) and/or ortho,meta (o,m) positions and the number of ortho-Cl-atoms (ortho-Cls). Plots of CB-X/CB-153 ratios in porpoise tissue vs the ratios in herring appeared to be linear for each CB group in all tissues. Slopes of these plots (metabolic slopes) were used as quantitative indicators of metabolic activity. In this way, activity of PB-type isozymes of the P450 monooxygenase system was apparent: in contrast to existing literature data, harbour porpoise appears to be able to metabolize congeners with m,p vic. Hs, even in the presence of more than 2 ortho-Cls. The presence of 3-MC-type (MC-type) isozymes was also detected. The metabolic slopes were also used as basis for risk assessment. Due to their metabolism the most toxic non-ortho CBs were not present in the tissues at detectable levels. We suggest a risk assessment approach which takes this into account. It is considered to be an alternative and more reliable basis for risk assessment than the use of toxic equivalent factors. The results support the model of equilibrium distribution of CBs in harbour porpoise and the role of blood as central transport medium. The model has been developed for persistent compounds; it appears to hold for metabolizable CB congeners as well.

Description: Individual chlorinated biphenyls (CBs) and chlorinated pesticides (p,p′-DDT and metabolites, HCHs and HCB) were determined in blubber samples of 40 harbour porpoises (Phocoena phocoena) of different age and sex from the North Sea, the Baltic Sea and Greenland coastal waters. Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were analysed in a selected group of animals. ΣCB concentrations (medians) in North Sea immature specimens were similar (14.9 μg/g lipid) to those from the Baltic Sea (17.0 μg/g lipid) and exceeding those in Greenland specimens by an order of magnitude (1.3 μg/g lipid). The median concentrations (μg/g lipid) of HCB, p,p′-DDE, p,p′-DDD and γ-HCH were in the order Greenland〈North Sea〈Baltic Sea. The highest concentrations of α-HCH (0.14 μg/g lipid) were found in the Greenland population, and p,p′-DDT was detected only in this group. The North Sea and Baltic Sea populations were identified as distinctly separate on the basis of levels and compositions of these contaminants. The ecological risk associated with dioxin-like toxicity was dominated by the CB congeners 118 and 170; the PCDD/Fs were playing only a minor role.

Description: Data on the carbonate system of the Northwestern Indian Ocean obtained on a cruise of F.S. Meteor during SW monsoon in July/August 1995 were compared with those of George et al. [George, M.D., Kumar, M.D., Naqvi, S.W.A., Banerjee, S., Narvekar, P.V., de Sousa, S.N., Jayakumar, D.A., 1994. A study of the carbon dioxide system in the northern Indian Ocean during premonsoon. Mar. Chem. 47, 243–254] collected during intermonsoon. In general, deep water values agreed well between the two expeditions. Surface waters, however, showed a substantial increase in dissolved inorganic carbon (CT) in the coastal regions due to strong upwelling in the SW monsoon. This was also accompanied by very high CO2 partial pressures in surface waters. The north–south gradients in vertical profiles of the measured parameters in the Arabian Sea are discussed by comparing profiles from the oligotrophic equatorial region with those from the highly productive central Arabian Sea. The effect of denitrification on regenerated CT and AT is minor, with contributions of 〈9 and 〈8 μmol kg−1, respectively, to the total amount regenerated also utilizing oxygen. The dissolution of biogenic carbonates is discussed; different approaches to define the depth, where the dissolution starts (lysocline(s), carbonate critical depth (CCrD)), are compared together with the calculation of saturation depth from carbonate concentrations. It is shown, that small differences in measured CT and AT (found between our data and those measured during GEOSECS) and different calculation approaches to the CO2 system (different dissociation constants for species involved and taking into account phosphate and silicate concentrations) can produce pronounced differences in the calculated saturation depths. However, CT and AT data suggest substantial dissolution of biogenic carbonate in the water column even above the calcite lysocline, irrespective of the procedures followed to calculate this horizon.

Description: Single and multidimensional GC-ECD techniques were applied to determine individual chlorobiphenyls (CBs) in solution and in suspended particles in the Baltic Sea (some data were also obtained for the adjacent German Bight in the North Sea). Large volumes (up to 1100 dm3) were analysed in transects in November 1988 and 1989 and in spring 1991. Salinity and temperature were measured continuously along the sampling tracks in all three cruises; nutrients and pH only in the latter two cruises. Concentrations of individual CBs in solution were in the sub- and low pg dm−3 range (detection limit being 0.05 pg dm−3), and of their sum between 2 and 237 pg dm−3. These concentrations are considerably lower than previously reported data. This is mainly the result of the elimination of contamination and interference problems in the sampling, clean-up and GC-ECD procedures. It may also partly reflect the reduction in the production and use of PCBs in the last decade. The highest concentrations in solution originated from local sources in the Belt Sea and the Gulf of Finland. Regional differences were found for the compositions of the CB mixtures in solution. The lowest concentrations of CBs in solution were found in areas and periods of plankton production (spring 1991), with ΣCB concentrations between 2 and 14 pg dm−3. The compositions of the CB mixtures showed regional differences in each cruise. These could be interpreted in terms of mixing between different water bodies. The classification of transects on the basis of these CB patterns agreed well with the distinction of water bodies on the basis of T-S diagrams and hydrochemical data. Concentrations of individual CBs in suspension were generally 0.1–0.5 pg dm−3, those of their sum (ΣCB) between 4 and 6 pg dm−3 during the autumn cruises. Extremely high values were found in the Belt Sea-Kattegat area in spring 1991 (up to 589 pg dm−3 for individual CBs and up to 2859 pg dm−3 for ΣCB). This probably reflects the uptake of CBs into particulates during a plankton bloom. Primary production may effectively remove CBs from the water column into the sediments. The amounts of chlorobiphenyls presently stored in the sediments of the Baltic Sea exceed the amounts in the water column by several orders of magnitude. The compositions of the CB mixtures differed considerably between solution and suspension. The relations between log K′d (apparent particle/water partition coefficient) and log Kow (octanol-water distribution coefficient) suggest the existence of (quasi-)equilibrium conditions in autumn. Deviations from this behaviour arise from biological activity in spring. The contribution of toxic congeners to the CB mixtures was dominated by the mono- and di-ortho-Cl substituted derivatives of the most toxic non-ortho-Cl CBs. The toxicity of the CB mixtures in solution was between 0.01 and 12fg dm−3 TEQs (TCDD toxic equivalents). CBs-77, -118, -105 and -156 had the largest contributions to TEQs.

Description: A coulometrically-based SOMMA system for the determination of total dissolved carbon dioxide (TCO2) in a continuous mode was designed and tested at sea. The new continuous technique approached the same high accuracy and reliability associated with prior discrete TCO2 measurements. During three cruises encompassing more than 19 weeks and 6000 continuous TCO2 measurements none of the three different systems tested exhibited any hardware-related failures. We found that coulometer cell lifetimes can greatly exceed prior expectations with many of the titration cells in the continuous mode remaining accurate for up to 72 h at carbon ages exceeding 50 mg C. We suggest a practical definition based on the CRM analyses for changing coulometer cells in the continuous mode. Systematic deviations of the SOMMA pipette volume from a theoretical temperature dependence were identified both from field data comparisons and pipette calibrations. Hence pipettes should be kept at constant temperature or they must be gravimetrically calibrated over the expected temperature range. Comparison of the continuous TCO2 data together with simultaneously measured additional CO2 system parameters showed that the refitted “Mehrbach” dissociation constants for carbonic acid best-represent fCO2 when calculated from TCO2 and alkalinity over a wide range of sea-surface temperatures and salinities. Some remaining systematic differences of calculated–measured fCO2 of up to 9 μatm likely reflect uncertainty in the temperature-dependence of the “Mehrbach” constants as well as possible uncertainty in the alkalinity–salinity relationship used to estimate alkalinity in the consistency checks.

Description: A seasonally-varying sedimentation pattern was observed for the alkenone flux measured with sediment traps in the northern North Atlantic. In the Norwegian Sea (traps were set at 500, 1000 and 3000 m) the alkenone flux varied between 0.1 and 7.1 μg m−2 d−1 and followed the seasonal pattern of the bulk parameters. Maximum fluxes occurred from mid-October until mid-November and were also high in May. A surprising result was that considerably higher particle fluxes were observed at 3000 m. For the alkenone flux, the highest additional input of 250% was observed during the period when sediment resuspension was greatest in summer. At the Barents Sea continental margin (traps at 1840 and 1950 m) the alkenone fluxes follow the sedimentation pattern of the bulk parameters, with a less visible signal of distinct seasonality observed in the 1950 m trap. The sedimentation of total alkenones varied between 0.8 and 144 μg m−2 d−1 at 1840 m and between 0.5 and 31.0 μg m−2 d−1 at 1950 m. Resuspension and lateral advection contributed significantly to measured fluxes in the two near-bottom traps. Alkenone concentrations were determined in faecal pellets of Appendicularia, ostracods and euphausids from selected samples at the Barents Sea site. The alkenone flux in pellets (4% to 24% of total) was 5 to 6 times higher at 1950 m depth than at 1840 m and the major part (77–78%) of the total flux of C37:3 reaching the near-bottom trap at 1950 m was associated with faecal pellets of the meso-zooplankton. Spatial and temporal variations of the U37k′ signals were observed, indicating that the imprint in the alkenone signal depends on the origin and transport pathway of the organic material. Strong deviations occur in areas where nepheloid layers contribute particles of long residence times to the primary flux.