Soft-bottom fauna, pollutants and metals in the sediments at Raudsand in Tingvollfjorden

Summary

Bergmesteren Raudsand AS plans to expand the industrial area at Raudsand in Tingvollfjorden, which includes, among other things, construction of a landfill (Deponi 2) and a rock fill and quay. In advance of the planned construction work, a survey has been carried out to assess the biological and chemical status in the fjord in accordance to the Norwegian Water Regulation (the national implementation of the Water Framework Directive). The survey was carried out in April 2019 at four stations (RU1, RU2, RU6 and RU7) in Tingvollfjorden. At each station soft-bottom fauna and sediments for analysis of metals and PCB7 were sampled. Ecological status was assessed by the biological quality element (BQE) soft-bottom fauna and the water region-specific substances copper (Cu), chromium (Cr), zinc (Zn) and PCB7 in the sediment. Soft-bottom fauna was classified as having "good" ecological status at all stations, however, the overall ecological status was downgraded from "good" to "moderate" due to high concentrations of copper, zinc and PCB7 in the sediments. Although the status of soft-bottom fauna was classified as "good" in accordance to the classifying system, it was clearly disturbed at several stations, having a low number of species and individuals. For the assessment of chemical status, the concentration of the priority substances (EU-priority pollutants) lead (Pb), cadmium (Cd) and nickel (Ni) were measured in the sediments. Both lead and cadmium showed "good" status at all stations. However, nickel concentrations exceeded the limit value (EQS), thus the overall chemical status was classified as "not good" at all stations.