Levels of PCBs in the aquatic environment of the Gulf of Bothnia: Benthic species and sediments

Abstract

The congener-specific analysis of polychlorinated biphenyls (PCBs) by HRGC/LRMS as part of a multi-residue method is described. The results displayed SDs, in general <30%, for replicate samples from the same sampling location. Results for 68 PCB congeners, resolved on a PTE-5 or DB-5 column, in benthic fauna (amphipods ( Monoporeia affinis), isopods ( Saduria entomon) and fourhorn sculpins ( Oncocottus quadricornis)) and sediments are presented for three coastal locations in the Bothnian Sea and two in the Bothnian Bay. The benthic fauna is suitable for monitoring environmental contaminants since it is stationary and it provides the staple diet of many fish and other predators. Sediments also give the contaminant loads of particular matter. Total PCB levels in the Bothnian Sea increased from north to south for sediments (∼ 1600–8500 ng g −1 extractable organic material), amphipods (∼ 400–1000 ng g −1 lipids) and isopods (700–2400 ng g −1 lipids). The levels in the Bothnian Bay were higher than in the most northerly location in the Bothnian Sea for sediments, amphipods and isopods. The trend for the sculpin samples from the different locations was, however, not so evident. A chemometrical comparison of the distribution of the PCB congeners at the different sampling sites using principal component analysis (PCA), revealed that PCB congener patterns differ between the Bothnian Bay and the Bothnian Sea.