Oil contamination of fish in the North Sea. Determination of levels and identification of sources

Abstract

Two fish species, cod and haddock have been sampled from five different regions in the Norwegian sector of the North Sea, the Haltenbanken and the Barents Sea. Three of the five sampling areas were located in regions with no local oil or gas production, while the remaining two areas represented regions with high density of oil and gas production fields. A total of 25 specimen of each of the two fish species were collected, and liver (all samples) and muscle (10 samples from each group) were analysed for the content of total hydrocarbons (THC), selected aromatic compounds (NPD and PAH) and bicyclic aliphatic decalines.

The present paper outlines the results of liver samples analyses from four of the sampled regions, the northern North Sea region and the three reference regions Egersundbanken, Haltenbanken and the Barents Sea. In general, no significant difference was observed between the hydrocarbon levels within the sampled regions. The only observed exception was a moderate, but significant increase in decaline levels in haddock liver from the Northern North Sea region. The qualitative interpretation of the results showed that the sources of hydrocarbon contamination varied within the total sampling area. This observation indicates that the local discharge sources in areas with high petroleum production activity are the sources of hydrocarbons in fish from such areas. However, it was not possible to identify single discharges as a contamination source from the present results.