THE EFFECTS OF FLUCTUATIONS IN NORTH-SEA FLOWS ON ZOOPLANKTON ABUNDANCE

Time series of annual mean zooplankton abundance observed by the Conti nuous Plankton Recorder Survey in the North Sea during the last three decades are compared with transports from a depth averaged storm-surge model by means of multiple regression analysis. In the northern areas , more than half the variance of Calanus finmarchicus can be accounted for by the winter flows. There are no statistically significant relat ionships in other North Sea areas or by using the flows from other sea sons. This is consistent with the accepted view that this copepod over winters in the North Atlantic and enters the North Sea in the early sp ring. The model flows are strongly related to the strength of the Nort h Atlantic Oscillation (NAO), which may explain the recently reported association of C. finmarchicus with the NAG. Other species do not exhi bit statistically significant relationships with any of the model flow s.