Phytoplankton and zooplankton in Subareas 48.1 and 48.2 in January–March 2020

Based on the results of RV Atlantida cruise in January - March 2020 in Subareas 48.1 and 48.2  data on the structure, quantitative indicators and spatial distribution of phytoplankton and zooplankton (species composition, abundance, biomass), primary production phytoplankton, chlorophyll concentration were obtained. Sampling stations were located above depths of 82 - 4300 m. Chlorophyll was studied at 180 stations, zooplankton and phytoplankton at 66 stations, and primary production at 66 stations. Phytoplankton during the summer period was represented by 120 identified species, mainly diatoms.  In the entire  study area, 4 phytoplankton communities were identified, which has different biotope conditions, spatial distribution and complex of the main structure-forming species. Zooplankton was represented by 53 species, mainly copepods. High correlations of surface concentration of chlorophyll a with the abundance and biomass of phytoplankton, primary production and chlorophyll content on average and integral for the photosynthesis zone have been obtained, which makes it possible to use remote satellite observations for assessments of abundance and productivity of phytoplankton as the basis of food chains, including krill, in the Atlantic sector of the Southern Ocean. Phytoplankton and zooplankton data are essential components for further analysis with the spatial distribution of environmental conditions and krill abundance to identify the relationships that determine ecosystem dynamics in the Antarctic sector of the Southern Ocean.