NEW DATA ON THE COMPOSITION OF CYANOBACTERIA AND ALGAE OF SOME WATERCOURSES OF THE KAMCHATKA PENINSULA

Abstract

The results of studying the biological diversity of the fl ora of freshwater algae in some streams of the Kamchatka Peninsula are presented, the structure of algal periphyton communities is revealed and the ecological characteristics of the studied algofl ora are given. The following rivers were surveyed: Kamchatka, Andrianovka, Plotnikova, Avacha, Paratunka, Gavanka, Kirpichnaya, Karymshina, Mutnushka and the Perviy stream. As a result of sample processing, 193 species, varieties and forms of cyanobacteria and algae from fi ve divisions were found: Cyanobacteria – 5 species, Bacillariophyta – 167 taxa (taking into account varieties and forms – 177), Ochrophyta – 2, Charophyta – 4, Chlorophyta – 5. In the algae communities of the surveyed water bodies, both in terms of abundance in fouling and species diversity, diatoms prevailed. The most common species, often growing on stones and dominating in fouling, were Encyonema minutum, E. silesiacum, Hannaea arcus, Gomphonema ventricosum, Ulnaria inaequalis, Cocconeis placentula, Fragilaria capucina, Nitzschia palea. Melosira varians, Meridion circulare, Planothidium lanceolatum, Gomphonella olivacea, species of the genera Staurosira, Diatoma, Cymbella, Fragilaria and some others were most often present as subdominants. In some cases, Rhoicosphenia abbreviata, Didymosphenia geminata, and Tabularia fasciculata took the fi rst places in terms of abundance. Of the Chlorophyta Ulothrix zonata and Cladophora glomerata were found. In a number of streams Hydrurus foetidus was encountered in mass. The division of Charophyta is represented by fi laments of Spirogyra and single specimens of the genera Closterium and Cosmarium. Cyanobacteria practically did not form mass fouling, except for the Tapinothrix genus. For each surveyed area, the species composition of algae was determined and complexes of dominant species were characterized. Giving a general ecological characteristic of the studied algofl ora, it should be noted that benthic and planktonic- benthic organisms predominate in periphyton communities, which are indiff erent to water salinity and prefer a slightly alkaline habitat.