A Possible Relation between the Production of Animal Plankton and the Current-System of the Sea

(1) The distribution of the two species Calanus finmarchicus and Calanus hyperboreus and the frequency of the species in different areas of the Norwegian coast waters during spring, has been found to depend upon the size of the winter stock in the deep waters of the fjords, and upon the currents carrying the individuals away from the winter areas after the yearly vertical migration of the species. (2) In the open oceans the more still-standing water masses, as first advanced by Helland-Hansen and Nansen (1909), appear to contain the stationary stock of plankton animals. From these waters the greater masses in the surrounding areas are renewed every spring. The water masses of the convection currents have been found to be characterized by an increasing deficiency of the species along their course, due to changes in ecological factors