Ecological studies on the phytoplankton of Korsfjorden, western Norway. The dynamics of a spring bloom seen in relation to hydrographical conditions and light regime

Publisher Website
Google Scholar
Abstract
The investigation was carried out at one station in Korsfjorden, a typical deep silled fjord of western Norway. During 14 cruises from 4 February to 30 June 1977 ATP, chlorophll a, phaeopigment a, and in situ 14C-assimilation were measured in the net (>30 μm), nano and ultraplankton (60% to the total primary production while net and nanoplankton dominated from 7 March to 13 April. The diatoms Skeletonema costatum, Chaetoceros compressits and C. debilis, and Rhizosolenia hebetata var. semispina made up the main part of the biomass on 21 March, 28 March and 4 April respectively. A shade adapted diatom society was located at the top of the nutricline in late June with S. costatum, Chaetoceros spp., and Thalassiosira spp. as the dominant species. The highest assimilation number of eight for the net plankton and four for the ultraplankton were found at the depth of 32% light intensity on 28 March and 24 May respectively. Linear relationships were found between chlorophyll a and ATP for the different size fractions with regression slopes ranging from 4.3 to 5.8. The total primary production for the period of investigation was calculated to 74 g C m−2. Light regime and water column stability were decisive factors for the outburst of the first diatom bloom in late March. Grazing on net plankton diatoms increased during late March-early April. Changes in the longshore wind-stress component were found to be essential for the understanding of the bloom dynamics.

This publication has 0 references indexed in Scilit: