TEMPORAL AND REGIONAL VARIATION IN THE COPEPOD COMMUNITY IN THE CENTRAL BARENTS SEA DURING SPRING AND EARLY SUMMER 1988 AND 1989

In this study, we examined a 3000 km(2) area to the southeast of Bear Island in the central Barents Sea with respect to copepod abundance an d depth distribution at nine stations in March, April and May of 1988 and 1989. In order to describe the population dynamics of the most pro minent species in the area during the period of study, the annual asce nt and abundance of Calanus finmarchicus, Metridia longa and Calanus g lacialis are shown. Stage abundance, vertical distribution and cohort development did vary between species and years at one site. The number of species and the complexity of the data for the entire area studied have encouraged us to search for more significant and persistent patt erns by using a canonical correlation analysis (CCA). We included a to tal of 27 species and stage categories, latitude, salinity and sigma f rom the nine stations in 1989. We performed this analysis for 1989, si nce we only have environmental data (CTD) available from the same stat ions in that year. The species-environment relationship showed that th e zooplankton community could not be grouped according to area (latitu de) or environmental (sigma, salinity) conditions during March-May in 1989. This means that the differences in environmental conditions in t he area of study in 1989 do not mediate any consistent gradient in the zooplankton community. When comparing the copepod data for both years , the largest differences are associated with the depth and month vect ors. The largest interannual Variation is seen in the copepod communit y in the depth strata from 100 to 400 m, and is related to a lesser de gree of similarity among the species and stages found in this depth in terval throughout the study. Two species were particularly responsible for the interannual differences: Pseudocalanus acuspes CV and females , and C.glacialis CV and adults. Changes in these two species are clea rly related to major shifts in the hydrographic conditions between the 2 years, where 1988 was generally colder compared to 1989.