Levels, trends and effects of hazardous substances in fjords and coastal waters – 2007

Sammendrag

This report is part of the Norwegian contribution to OSPAR’s Coordinated Environmental Monitoring Programme (CEMP). CEMP 2007 included the monitoring of contaminants in blue mussel (51), dogwhelk (9), cod (9) and flatfish (11) along the coast of Norway from Oslo to Varangerfjord. The results showed elevated, in a few cases up to severely contaminated, levels of contaminants in the inner Oslofjord (PCBs, mercury and lead in cod; PCBs in blue mussel), and Sørfjord and Hardangerfjord (DDT, lead, cadmium and mercury in blue mussel; mercury and DDT in cod). The results from the remaining stations showed low or moderate levels of contamination in 2007. Considering the whole monitoring period (1984-2007), a significant upward trend was found for mercury in cod from the inner Oslofjord. A significant downward trend was found for lead and cadmium in blue mussel from Sørfjord/Hardangerfjord. The “Pollution" index was between “marked” and “severe”. Contamination of organotin in blue mussel and imposex in dogwhelk were still apparent, however, most of the trends were downward indicating that regulatory action has lead to an improvement in the investigated areas. The results from studies using biological effects methods in cod, indicated reduced contaminant levels in the Sørfjord. Analyses of brominated flame retardents, perfluoralkyl compounds, and TBT in stored samples of cod liver from the Oslofjord indicated similar exposure in 1993 as in 2007. The sources of statistical variance is also discussed in respect to optimization of CEMP sampling strategies.