Ecological studies on the deep-water pelagic community of Korsfjorden, western Norway. The topography of the area and its hydrography in 1968–1972, with a summary of the sampling programmes

Abstract

Korsfjorden has a 690 m deep basin separated from the open sea by a sill at 180 m depth and by deeper sills from the inner fjord complex. Seasonal effects of temperature are apparent down to a depth of 300 m, below which temperatures show little variation. The salinity of the deep water is always greater than 35‰, characteristic of oceanic (Atlantic) water. The deep water oxygen content shows evidence in the early months of each year of renewal of the deep water by oceanic water originating, it is presumed, at the surface. Estimates of timing and duration each year are given, based on interpretation of TS diagrams and the oxygen data. The initial sampling programme, 1968–1970, consisted of monthly horizontal transects of the water column with pelagic trawls. The revised programme, 1971 onwards, consists of oblique divided and undivided hauls of the whole water column with a pelagic trawl (mesh size 1 mm) and a smaller net (mesh size 0.5 mm). Preliminary analysis of some copepods and a mysid indicates that samples taken with these two nets can be standardized to make them directly comparable and complementary.