Net phytoplankton was studied in 10 stations situated west of Elephant Island along three transects located in the Scotia Front zone and in 2 stations situated in the eastern Bransfield Strait. Altogether 70 algal taxa were identified. Phytoplankton density and seston biomass were the highest in stations neighbouring the Scotia Front from the south. In the Scotia Front region Corethron criophilum was a dominant species. Phytoplankton community of the region is rather uniform, however the closer comparison of the phytoplankton species composition allowed to distinguish 4 stations groups. This division is concordant with the hydrological one. A different phytoplankton community was recorded in the eastern part of the Bransfield Strait.

Phytoplankton sampling from 13 stations situated in Admiralty Bay was carried out in March. April, May, October and November 1983. Wet settling volume of seston, its dry weight, number of cells under 1 m2 , and qualitative composition of phytoplankton were determined. It was found that amount of phytoplankton was decreasing in April and increasing again in November after the winter season. The share of benthic and periphyton species in the qualitative composition of phytoplankton was quite significant, whereas their quantitative share was rather small. 163 taxa of algae were identified in the net phytoplankton; among these 107 taxa were reported for the first time from the Admiralty Bay. Most abundantly met throughout the entire study period were: Corethron criophilum and Thalassiothrix antarctica.