The present study provides a comparative analysis of the structure and quantitative characteristics of algae from different biotopes in the shore zone of Bolshye Koty Bay (interstitial waters in the splash zone, water at the shoreline and 100 m off). First data on the algal communities in the interstitial waters of the splash zone are presented. Sixty three micro-and macro algal species were encountered during 3-year long investigations. Benthic diatoms, as well as colonial and filamentous cyanoprokaryotes (blue-green algae) were identified as major primary producers among microalgae. Regardless of the presence of significant amounts of valve fragments and empty tests of planktonic and benthic diatoms (sometimes > 90 % of the total amount), we registered the highest biomass of algae in this habitat during summer time, since it was mainly composed of macroalgae thrown up by the waves onto the beach: Ulothrix zonata, Cladophora compacta, Tetraspora cylindricavar. bullosa and Didymosphenia geminatа. At the same time, U. zonata filaments, detached from substratum and floating, constituted the main part of the phytomass in the water at the shoreline, and a smaller part was made up by benthic microalgae genera: Hannaea Patrick, Gomphonema Ag., Cymbella Ag., Nitzschia Hassal. Only in late spring and autumn, substantial amounts of planktonic algae were encountered at this site. The composition of phytoplankton 100 m off the shore was similar to the pelagial phytoplankton with a small admixture of benthic forms.