Abstract <p>The composition, diversity, and distribution of zooplankton were studied in Fram Strait and in the southern Barents Sea during the winter period. Multivariate analysis revealed a clear separation of the sampling stations based on oceanographic, bathymetric, and food conditions. Two types of zooplankton assemblages were delineated, and these corresponded to the two study regions. Copepods dominated by abundance and biomass. Generalized linear models showed a close relationship of the abundance of common zooplankton groups and diversity indices with mean water temperature, salinity, depth, and chlorophyll <i>a</i> concentration. An increase in the proportion of boreal species and in the total biomass suggested Atlantification of marine Arctic zooplankton communities as well as a positive impact of warming on the development of zooplankton.</p>