Comparison of the phytoplankton assemblages of the south-eastern Barents Sea and south-western Kara Sea: Phytogeographical status of the regions

A comparison of the taxonomic composition of the diatom and dinoflagellate assemblages has been carried out for the south-eastern Parents Sea (Pechora Sea) and the south-western Kara Sea. All available literature and original data have been used in making the floristic lists which have been correcte d for synonymy. The number of microphytoplankton species found in the south -western Kara Sea is somewhat higher than in the south-eastern Parents Sea (221 vs. 184 species respectively). The difference is most significant for the dinoflagellates (88 vs. 67 species). Diatoms formed a major part of the communities, accounting for 60% of the taxonomic composition in the Kara S ea, and 63% in the Parents Sea. In both regions, about 60% of the diatom as semblages are represented by centric diatoms, most of them being typical pl anktonic chain-forming species. A high similarity between the two areas was characteristic for most phytogeographical and ecological groups of the pel agic microalgae, and therefore we suggest that the plankton communities for m a floristic entity with the status of a phytogeographical province. We na me it the Novaya Zemlya Phytogeographical Province. The major reason for co nsidering these two areas a biogeographical unit, is the similarity in the microphytoplankton assemblages and the stable water exchange which exists b etween the areas.