AN HYPOTHESIS CONCERNING THE SPACE-TIME SUCCESSION OF CALANUS-FINMARCHICUS IN THE NORTHERN NORTH-SEA

An hypothesis which explains the space-time succession of Calanus finm archicus in northern European waters is presented. The hypothesis is b ased on observations of the regional abundance and behaviour of C. fin marchicus during its life cycle, and on knowledge of the water mass di stribution and general circulation of the North Sea and of the adjacen t continental slope margins. The basis for the hypothesis is supported by modelling of the general features of the continental slope dynamic s. An integral part of the hypothesis is the existence of a poleward-f lowing eastern boundary jet at the north-west European shelf edge and a counterflow at depth. The final conclusion is that the succession of C. finmarchicus can be explained by a series of space-time cycles alo ng the continental slope of the North Sea and the southern Norwegian S ea in which an intricate combination of hydrodynamics and the migratio n behaviour of this species play an important role.