Abstract
The extent of pollution in the marine environment near the city of Tromsö was investigated at seven selected localities from August 1979 to March 1981. Measurements of hydrographical factors (dissolved oxygen, salinity, temperature) and amounts of plant nutrients (orthophosphate, nitrate) did not indicate cronic marine pollution of the water masses near the city. This is probably due to strong tidal currents which spread sewage waste-water over large areas in a fairly short time.
Rates of sedimentation of organic matter were relatively high near Tromso compared to localities about 15 km from the city. In situ redox measurements suggested a decrease in organic enrichment of the soft-bottom sediments with distance from the centre of Tromsö. A similar decrease was also observed in the concentrations of heavy metals (mercury, cadmium, lead, zink) both in soft-bottom sediments and in sedimenting material. It is concluded that the exposure of soft-bottom sediments to urban pollution is very local near the centre of Tromso compared to the controls outside the city area, and that in general only the seabottom near the waste discharge-points is influenced by pollution from the city.