Abstract
The epibenthic macrofauna of wooden pier-pilings at six sampling stations in the Tromsö area were investigated at 6–7 weeks interval between August 1979 and September 1980. The aim of the study was to determine if there were qualitative and quantitative differences between the fauna near the city of Tromsö and that closer to the open sea, and if any faunal differences could be related to sewage from the city.
The substrate and hydrographical environment (salinity, temperature, oxygen) were fairly similar at all sampling stations. The sampling stations furthest away (c. 15 km) from the main sewage outlets had more species, a higher diversity and a lower dominance than the other sampling stations. Although log-normal distribution and Czekanowski's index of similarity also suggested that the faunal differences between the most remote stations and those nearest the sewage outlets, were significant, they were small and it is concluded that the sewage from the city had fairly small effects on the fauna. This is due to the strong tidal water exchange and mixing around the island of Tromsö, especially in the sound between the island and the mainland.