The influence of water exchange on zooplankton dynamics and species development in a south Norwegian fjord

• Published in: Journal of Plankton Research
• Main Authors: Krause, Michael, Kattner, Gerhard
• Format: Text
• Language: English
• Published: Oxford University Press 1989
• Subjects: Articles; Calanus finmarchicus; Copepods
• Online Access: http://plankt.oxfordjournals.org/cgi/content/short/11/1/85; https://doi.org/10.1093/plankt/11.1.85

During experiments in a south Norwegian fjord in March and April 1979, distribution and development of zooplankton were investigated in detail. Numbers of protozooplankton, meroplankton and holoplankton were determined as individual species. Strong water exchange caused a high variability in plankton composition and biomass. Changes in salinity and temperature as well as numbers of plankton individuals and in the percentage composition of the developmental stages of the spring spawning Calanus finmarchicus revealed that a wind-induced inflow of Skagerrak water along the southwest Norwegian coast also entered the Rosfjord. In contrast to the Atlantic water with low numbers of copepods from the hibernating generation, in the Skagerrak water the spring generation of C.finmarchicus had already developed up to the first and second copepodite stages. The Skagerrak water was already very rich in phyto- and zooplankton organisms. Here, an increase in biomass over time mainly resulted from the development of younger to older copepodite stages and from a considerable increase in numbers of the tintinnid, Leprotintinnus pellucidus . The vertical distribution of plankton organisms and fecal pellets was closely associated with the occurrence and the stratification of water masses coming into the Rosfjord.