With petroleum exploration and development expanding in the Arctic (AMAP, 2007) As expected, the bioconcentration factor (BCF) for B[a]P was higher than for phenanthrene in accordance with a higher octanol/water partition coefficient for B[a]P (log K ow = 6.04) compared to phenanthrene (log K ow = 4.53). However, for both compounds, log BCF was lower than log K ow that may indicate active biotransformation and excretion of the selected PAH compounds. These findings on the bio-uptake kinetics for petroleum hydrocarbons are essential for evaluating the potential consequences of an oil spill in the Arctic.
Copepods of the genus Calanus are keystone species in the transfer of energy from lower to higher trophic levels of the Arctic/sub-Arctic food web. We performed experimental tests on the reproduction and feeding of Calanus spp. exposed to the water-soluble fraction (WSF) of crude oil. Fecal pellet and egg production were examined for females of C. glacialis exposed to WSF (16 EPA) concentrations of 10.4 µg l -1 (high treatment; HT), 3.6 µg l -1 (low treatment; LT) and 0 µg l -1(control treatment; CT). We observed no significant difference in cumulative egg or fecal pellet production. Egg hatching success was examined for 2 d after transferring eggs from treatment solutions to uncontaminated seawater. Hatching success was significantly lower in the HT compared to the CT. In a second experiment, feeding of C. finmarchicus was examined after exposure for 11 and 18 d to 7.0 (HT), 3.4 (LT) or 0 (CT) µg l -1 of WSF (16-EPA). Using algae cell concentrations as a proxy for feeding success, feeding was inhibited for C. finmarchicus specimens exposed to the HT of WSF compared to the CT. Our findings indicate that adult females of C. glacialis may withstand some exposure to crude oil components but the survival of offspring is negatively affected. Reduced feeding efficiency in C. finmarchicus exposed to high concentrations of WSF provides evidence that adult specimens are sensitive to exposure to crude oil. The study expands on the limited body of knowledge of potential changes to key life history traits of Arctic Calanus species resulting from exposure to chemical compounds in crude oil.
In the Barents Sea region new petroleum fields are discovered yearly and extraction of petroleum products is expected to increase in the upcoming years. Despite enhanced technology and stricter governmental legislation, establishment of the petroleum industry in the Barents Sea may potentially introduce a new source of contamination to the area, as some discharges of produced water will be allowed. Whether the presence of produced water poses a risk to the Arctic marine life remains to be investigated. The aim of this study was to examine effects of exposure to several compounds found in produced water-a mixture of selected organic compounds (APW), radium-226 ((226)Ra), barium (Ba), and a scale inhibitor-on the copepod species Calanus finmarchicus. Experiments were performed using exposure concentrations at realistic levels based on those detected in the vicinity of known discharge points. The influence of lethal and sublethal effects on early life stages was determined and significantly lower survival in the APW exposure groups was found. In the Ba treatment the life stage development did not proceed to the same advanced stages as observed in the control (filtered sea water). The scale inhibitor and (226)Ra treatments showed no significant difference from control. In addition, adult females were exposed to APW, (226)Ra, and a mixture of the two. Both individual-level effects (egg production and feeding) and molecular-level effects (gene expression) were assessed. On the individual level endpoints, only treatments including APW produced an effect compared to control. However, on the molecular level the possibility that also (226)Ra induced toxicologically relevant effects cannot be ruled out.
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