Species point records from 1991 MNCR/UMBSM Norwegian fjords survey

Fjords in two areas of south-west Norway were surveyed to compare the benthic communities present with those found in Scottish sealochs. The results will assist in the evaluation of the nature conservation importance of habitats and communities in Scottish lochs. Forty four sublittoral sites were surveyed by diving to a maximum depth of 50m, and a number of shores were examined in a range of physiographically different fjords. Surface water temperatures, surface salinity reductions and water quality were all generally greater than in most Scottish lochs. The tidal range and strength of tidal currents were markedly reduced compared with western Scotland, and consequently the extent of oxygen depletion in enclosed basins was significantly higher. The variety, extent and richness of shore communities was very limited, due to the restricted tidal range (<0.6m) in the area and to reduced surface salinities throughout many of the fjords examined. The variety of sublittoral habitats present was limited, in comparison with areas of similar physiographic complexity in western Scotland, by the lack of tidal currents and the predominance of bedrock habitats in the upper 50m of the fjords examined. Prominant Scottish sealoch communities from current-swept habitats, such as beds of maerl, horse mussels and brittlestars, were either not found or were poorly developed in the fjords studied. The sublittoral rocky communities encountered in the fjords were broadly compatable with those known from the Scottish lochs, although there were notable variations in both species composition and zonation patterns. Circalittoral rock, especially vertical faces, was very well represented in the fjords. Sublittoral epibenthic sediment communities were poorly developed compared with similar sediment habitats in Scottish lochs. Bryozoans, fish, sponges and calcareous tube worms were better represented in the fjords, in terms of species numbers and/or abundance. In contrast, crustaceans, molluscs, hydroids and burrowing anenomes were less well represented. Over 460 taxa were recorded during the present fjord survey, of which about 95% have been recorded from recent surveys in Scottish lochs. Records currently considered sensitive have been removed from this dataset.