One-centimeter slices of sediment sampled at 2-4 cm intervals were analyzed for diatom abundance, species richness, and species identification. Diatom abundance and taxon identification was performed using an Olympus BX-43 light microscope at 1000x. A total of 213 diatom species were found in 175 samples from the studied sediment. More than 300 diatom frustules were identified to the species level to obtain a special statistical distribution of the diatom assemblages. Sediment samples with very few diatom frustules were enriched using a heavy liquid technique to obtain the required statistical number of specimens. Diatom abundance expressed as the number of frustules per 1 g of dry sediment (fr./g); species richness as the number of species per sample (species/sample), and the percentages of each species in the diatom taxa assemblages were calculated.Diatom sea ice group includes species habituated directly in sea ice or ice surfaces and present typical sea ice species of the Artic and subarctic regions such as Fragilariopsis oceanica (Cleve) Hasle, Fragilariopsis cylindrus (Grunow) Kreiger, Thalassiosira hyalina (Grunow) Gran, Thalassiosira kryophila (Grunow) Jørgensen and Thalassiosira nordenskioeldii Cleve.Sea ice transported group includes allochthonous benthic and freshwater species, captured by sea ice on the shelf during winter ice formation, transported by surface water currents and dropped into bottom during ice melting. Benthic diatoms are represented by the genera Cocconeis, Delphineis, Diploneis, Navicula, etc. Freshwater diatoms are represented by the species Aulacoseira subborealis (Nygaard) Denus, Muylaert et Krammer and genera Amphora, Fragilaria, Pinnularia, Placoneis, Planctonella, Surirella, Cymbella, etc.