Continuous plankton records - zooplankton and environment, northeast atlantic and north-sea, 1948-1975

Abstract

Principal components analyses are used to describe the major year-to-year changes in the abundance of the zooplankton of the North-East Atlantic and the North Sea for the period 1948 to 197 5.There is a marked degree of coherence both between species and between different parts of the area.The changes show persistence from year-to-year in the form oflong term trends.The main pattern of differentiation between the species is related to their geographical distributions.Interpretations of the year-to-year changes are presented, based on empirical associations with climatic factors, which suggest that changes in the North Atlantic current, and more localised wind-driven advection play a major role in determining the year-to-year changes.ltwould appear the variations in abundance are influenced primarily by densityindependcnt factors.