Impact of a controlled freshwater discharge on zooplankton distribution in a Norwegian fjord

Stein Kaartvedt*, Eirik Nordby

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

11 Scopus citations


Investigations were carried out in a 20-km long fjord branch before and during a controlled freshwater discharge (230 m3·s-1) from a hydroelectric power plant located at the head of the fjord. Advection notably structured horizontal and/or vertical distributions of zooplankton during discharge. Brackish water species were mainly confined to the upper 2 m throughout the experimental period, and were swept out of the fjord with a surface current generated at onset of discharge. Marine species avoided the upper brackish meter; they were otherwise mainly concentrated in the upper layer, but mean depths descended slightly during discharge. Both net outward flushing with the surface current and net transport in with the compensation current were recorded among marine species. Acartia clausi behaviourally modified the effect of the advective process by performing diel vertical migrations between the outgoing surface current and incoming compensation current, and abundance in the fjord branch was not affected by the discharge.

Original languageEnglish (US)
Pages (from-to)279-293
Number of pages15
JournalJournal of Experimental Marine Biology and Ecology
Issue number2
StatePublished - Nov 2 1992
Externally publishedYes


  • Advection
  • Fjord
  • Hydroelectric
  • Retention

ASJC Scopus subject areas

  • Ecology, Evolution, Behavior and Systematics
  • Aquatic Science


Dive into the research topics of 'Impact of a controlled freshwater discharge on zooplankton distribution in a Norwegian fjord'. Together they form a unique fingerprint.

Cite this