Predicting Calanus Finmarchicus Abundance from a Climatic Signal

Long-term fluctuations in the abundance of the copepod Calanus finmarchicus in the north-east Atlantic are compared to the North Atlantic Oscillation index over the period 1958–1995. The strong climate-plankton link previously observed is confirmed and a simple linear regression model is constructed with the aim of predicting the abundance of the species several months in advance. For the years 1993–1995 the model predictions are in accordance with observations, but not in 1996 when the abundance of C. finmarchicus fell, although the climatic scenario indicated that a sharp increase should have occurred. The potential causes of this discrepancy are discussed.