CHANGES IN THE ZOOPLANKTON COMMUNITY OFF THE COAST OF NORTHUMBERLAND BETWEEN 1969 AND 1988, WITH NOTES ON CHANGES IN THE PHYTOPLANKTON AND BENTHOS

Species abundance data for the holoplanktonic fraction of zooplankton samples taken monthly from 1969-1988 at a station off Northumberland o n the north-east coast of England (western North Sea) have been combin ed to give annual geometric mean abundances and subjected to multi-dim ensional scaling (MDS) ordination. The years are found to fall into tw o groups (1970s and 1980s) with a distinct transition in community str ucture between 1979 and 1980. The macrobenthos at a nearby benthic sta tion subject to long-term annual sampling also falls into two groups b ut with a transition in community structure occurring a year later bet ween 1980 and 198 1, and similar results have been reported for pelago s and benthos in the eastern North Sea. The monthly and mean annual ab undances of the more numerically important species of the zooplankton are examined to see if consistent patterns of change are discernible. The changes seen are found to be complex and varied, and not the resul t of changes in abundance of a few dominant species. The results are e xamined in the context of long-term climatic changes in the north-east Atlantic and changes in the phytoplankton off Northumberland.