1 gC m2 yr−1 (Carroll et al. 2008b). This may indicate that contaminants at this location are diluted by organic material associated with high rates of primary productivity in the region. Studies

of organic contaminants GSK2118436 clinical trial typically report on different congeners, making it difficult to compare results among different investigations. Thus, we adopt the strategy of Gustafsson et al. (2001) and evaluate CB52 alone as an indicator of site-to-site differences in contaminant supplies. The CB52 fluxes at our stations were 79–146 pg m−2 d−1 (station I), 62–304 pg m−2 d−1 (station IV), 138–853 pg m−2 d−1 (station III) and 33–341 pg m−2 d−1 (station VIII). In the Baltic Sea, CB52 fluxes were ~ 400 pg m−2 d−1, whereas in Baffin Bay, CB 52 fluxes were considerably lower, ranging from 19 to 56 pg m−2 d−1 (Savinov et al. 2000). Thus, CB 52 burial fluxes for the Barents Sea are generally higher than those at the Baffin Bay site in the Canadian Arctic and comparable to fluxes in the more heavily industrialized Baltic Sea area: this is quite an astonishing

feature, considering the long distance between Gefitinib industrial sources and the study area. HCB concentrations in surface sediments (stations III, IV and VIII only) were 0.5–2.0 ng g−1 d.w−1 (Table 2). Previous measurements of HCB levels in sediments from Guba Pechenga (northern Russia) and the southern Barents Sea shelf ranged from 0.3 to 1.8 ng g−1 d.w−1 (Savinov et al. 2003). These sediment concentrations are higher than those reported for the Bering and Chukchi Seas (0.04 to 0.08 ng g−1 d.w−1) (Iwata et al. 1994), while concentrations up to 6.7 ng g−1 d.w−1 have also been reported in some harbours of northern Norway (Dahle et al. 2000). At stations III and VIII the highest HCB burial fluxes (Figure 5) are observed at surface sediments and decrease down-core. Although the industrial, direct production of HCB in Europe and N. America ended in the early 1990s (no data from the former USSR is available), this

recent contamination may have originated from the production of other chlorinated P-type ATPase compounds, such as perchloroethylene, carbon tetrachloride and, to some extent, trichloroethylene, polychlorinated-p-dioxins and polychlorinated dibenzofurans (CEPA 1993). The pattern of HCB burial flux at station IV is constant and similar to the pattern observed for ∑7PCB (Figure 5), which again provides confirmation of the strong sediment mixing there (Zaborska et al. 2008). The dominant PCB congeners in the western Barents Sea are CB101, CB153 and CB138 (Figure 6). However, the southernmost station (I) has a lower total PCB concentration than the other stations. Moreover, these sediments exhibit no dominant PCB congener. In contrast, CB 101 dominates the composition at station IV, accounting for 23–28% ∑7 PCB. At station III CB 101 is predominant (22–41%), particularly in the deeper sediment layers. In addition, the congeners CB 153 and CB 138 are important at station III.