The Entrapment of Pollutants in Norwegian Fjord Sediments—A Beneficial Situation for the North Sea
- S.-D. Nio,
- R. T. E. Shüttenhelm and
- Tj. C. E. Van Weering
Published Online: 29 JUN 2009
Copyright © 1981 The International Association of Sedimentologists
Holocene Marine Sedimentation in the North Sea Basin
How to Cite
Skei, J. (1981) The Entrapment of Pollutants in Norwegian Fjord Sediments—A Beneficial Situation for the North Sea, in Holocene Marine Sedimentation in the North Sea Basin (eds S.-D. Nio, R. T. E. Shüttenhelm and Tj. C. E. Van Weering), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444303759.ch32
- Published Online: 29 JUN 2009
- Published Print: 23 DEC 1981
Print ISBN: 9780632008582
Online ISBN: 9781444303759
- symptoms of eutrophication and increased primary production;
- efficient trapping of pollutants in fjord sediments;
- mobilization of sedimented pollutants;
- hexachlorobenzene (HCB);
- polycyclic aromatic hydrocarbons (PAH)
Fjords in Norway are frequently used as recipients of industrial and domestic wastes. Due to the estuarine circulation, multi-layered flow and long periods of stagnancy in the bottom water, effluents containing metals and organic micro-pollutants are to a large extent removed from the water and incorporated in the sediments. Some fjords show symptoms of eutrophication and the increased primary production enhances the settling of pollutants tied up with organic debris. Additionally, Norwegian fjords are often topographically confined, which also restricts the transport of pollutants to the North Sea and the Skagerrak.
Studies of the chemical composition of sediment cores in a number of polluted fjords in Norway suggest that metals and non-degradable organic compounds are fixed in the sediments close to the source. This is illustrated by steep horizontal gradients of pollutants (Hg, Zn, Pb, Cd, HCB, PAH) in the surface sediments.
Preliminary results indicates that discharge of pollutants to fjords causes local problems with elevated levels in biota, waters and sediments. The waste discharge often takes place below the seaward-flowing surface layer, i.e. in the compensating current, transporting the pollutants towards the head of fjords. The result is an efficient trapping of pollutants in the fjord sediments and the amount of waste being transported out of the fjords and into the open ocean is apparently small. This is not to say that the sediments act as a permanent sink for pollutants, but any pollutants reintroduced into the water are not likely to impose any threat to the environmental quality of the North Sea.