Publication Abstract

Long-term changes in zooplankton andthe climate of the North Atlantic

B. Planque and A.H. Taylor

Long-termvariations in zooplankton abundance in the north-east Atlantic, the North Sea, and infreshwater UK lakes are investigated by means of the Continuous Plankton Recorder surveyand the Windermere and Esthwaite lakes data. Inter-annual variability of planktonabundance in these data sets shows strong correlation with two modes of climaticvariability in the North Atlantic: the latitudinal shifts of the north wall of the GulfStream and the North Atlantic Oscillation. Detailed analyses reveal that the connectionbetween environmental forcing and plankton response depends on various mechanisms, i.e.,timing and intensity of the spring phytoplankton bloom resulting from changes instratification levels, changes in temperature, and, in the case of the copepod Calanusfinmarchicus, advection of the population into the North Sea at the end of the winterseason. Future attempts to predict changes in marine ecosystems on the basis of climatescenarios will require focusing major effort on biological-physical modelling andlarge-scale plankton population ecology. The maintenance of long-term monitoringprogrammes is also essential to determine whether the climate-plankton connectionsobserved during several decades will persist in the future or will be overruled by othermechanisms and principally human-induced perturbations.

Reference:

B. Planque and A.H. Taylor, 1998. Long-term changes in zooplankton and the climate of theNorth Atlantic. ICES Journal of Marine Science, 55: 644-654.