Quantities of zooplankton and propagation of calanus finmarchius at permanent stations on the norwegian coast and at Spitsbergen, 1959-1962
Abstract
1. Zooplankton has been collected in vertical hauls from 1959 to 1962
at four permanent oceanographic stations along the coast of Norway
and one from Spitsbergen. The volumes have been measured and the
stage composition of Calanus finmarchicus determined.
2. A delay of occurrence of maxim volume with increasing latitude
for the spring maximum of volume is evident, but a similar trend for
the secondary maxima could not be demonstrated. The annual
richness of zooplankton on the southernmost station (Sognesjøen)
was considerably poorer than at the other four stations. At these the
amount of zooplankton was of the same order of magnitude. There
were large variations in amount of zooplankton from one year to
another at all stations, and a general conclusion about the relative
richness of the different years could not be made.
3. A significant delay in the time of spawning of Calanus finmarchicus
and decreasing number of spawnings with increasing latitude was
demonstrated.
4. Maximum of volume occurred about 1½ to 2 months later than the
spawning of Calanus finmarchicus when the copepodite stages III
and IV in southern Norway and IV and V in northern Norway
comprised more than 50% of the stages. A method for prediction
of biomass changes based on development-stage distribution of Calanus
is suggested.
Publisher
[Fiskeridirektoratets havforskningsinstitutt]Series
Fiskeridirektoratets skrifter, Serie Havundersøkelservol 13 no 8