Monitoring of contaminants in Kristiansandsfjorden in 2013. Investigations of blue mussel.

Summary

Kristiansandsfjorden has previously received higher loads of pollutants than today. The fjord still remains partly contaminated, but is evolving towards a better environmental quality. This is partly due to emission reductions and the implementation of remedial measures. This report presents the results from environmental monitoring performed by NIVA in Kristiansandsfjorden in 2013. The work has been performed on contract from the County Governor of Vest-Agder and is a continuation of an annually monitoring programme that began in 2010. The purpose of the work was to monitor the levels of contaminants in blue mussel. Blue mussel was collected at seven stations (Figur 1, Figur 2) where Marvika (in Topdalsfjorden) represents the inner fjord area. Lagmannsholmen, Odderøy, Svensholmen, Voie/Kjosbukta and Bragdøy are all located in the central, urban fjord area (Vesterhavn and Fiskåbukta) and Flekkerøygapet/Kjeholmen is the reference station located in the outer fjord area. Blue mussel was collected in September and October 2013, except for Marvika and Lagmannsholmen where blue mussel was transplanted (deployed in September and retrieved in October). At Svensholmen, blue mussel was also sampled in May and July in order to detect possible seasonal trends. The mussel was analysed for mercury (Hg) and 13 other metals like silver (Ag), aluminium (Al), arsenic (As), calcium (Ca), cadmium (Cd), cobalt (Co), copper (Cu), chromium (Cr), iron (Fe), nickel (Ni), lead (Pb), silicon (Si) and zinc (Zn). Mussel was also analysed for organic tin compounds (TBT), polycyclic aromatic compounds (PAHs), polychlorinated biphenyls (PCBs), dioxins and dioxinlike (non-ortho) PCBs, hexachlorobenzene (HCB) and hexachlorobutadiene (HCBD).