SOFT-BOTTOM MACRO INVERTEBRATE FAUNA OF NORTH NORWEGIAN COASTAL WATERS WITH PARTICULAR REFERENCE TO SILL-BASINS - PART ONE - BOTTOM TOPOGRAPHY AND SPECIES-DIVERSITY

The soft bottom macrofauna of three fjords in Northern Norway is prese nted and compared. One fjord is open, with gradually decreasing water depth from mouth to head, and two fjords possess shallow sills, splitt ing the fjords into two and three basins respectively. The most southe rly samples were collected from Rombaken in the innermost part of the Vestfjord, at approximately 68 degrees 23' N; 17 degrees 32' E, close to the city of Narvik. The northernmost samples were collected from Ak karfjord at 70 degrees 46' N; 23 degrees 25' E, near North Cape, Europ e's northernmost tip. The ten numerically most abundant taxa at each s tation are listed, together with a description of bottom topography, s ediment composition and the extent of anthropogenic impact on the fjor d. Data are presented on species diversity related to water depth, sed imentary TOC content and presence/absence of shallow sill(s). The domi nant faunal groups present are the Polychaeta and Mollusca. In sill ba sins echinoderms are absent or poorly presented. Species composition g enerally appears to be most influenced by bottom topography and sedime nt composition. Waste discharge appears to have only local effects on the faunal assemblages investigated. The TOC content of the bottom sed iments tends to increase from exposed, outer parts to the landward par ts near the head of the fjord basins. Faunal diversity decreased from open areas (mouth of fjords) towards the sill basins.