Abstract:

According to comprehensive oceanographic survey zooplanktonic data were obtained in the Chukchi Sea (66°00′-75°25′N,153°36′-174°59′W) during the period from July to August 1999. The diversity of the species, ecological group and community construction were analyzed. The geographical locations, ecological characteristics and dominant species of the community habitats,the horizontal and vertical distribution of the total biomass and percentage of the major taxa of zooplankton in the zone in summer were described. The interrelation of the distribution characteristics with the environmental factors was discussed. A comparison of species diversity and biomass of this area with that of related sea areas was made. It shows that 4 ecological groups of 84 recorded zooplankton species coexisted in this area with quite different compositions, i.e. they formed 3 communities of different ecological properties in areas in the south and north of 70°N latitude and in deep waters in the northeast. The pattern of distribution is associated with the status of currents and water masses in the areas. It showed that total biomass was lower in the deep waters and higher in the shallow waters, particularly in the south end of the latter, by horizontal distribution. The vertical distribution of species richness showed lower in upper water layers and it increased downwards to the depth of 500m and slightly decreased in layers from 800 to 500m during the dust. The biomass appeared high in water layers in depth less than 200m, particularly in depth of 50-0m, and it decreased in depth beyond 200m. Zooplankton biomass with low value of species diversity was rather high in comparison with the biomass in water of the low and middle latitude. Besides, the vertical distribution of zooplankton diversity was quite different from that in the tropical region.