Різноманіття та екологічні характеристики водоростей водної товщі суббасейну крупних придунайських озер в осінньо-зимовий період (Україна)

Abstract

The paper deals with structural and functional components of diversity and ecological characteristics of algae in the water column of the large Danubian lakes Kahul, Kartal, Yalpuh, Kuhurluy, Katlabukh, and Kytay in the late autumn-winter of 2019–2020. The water column algae’s taxonomic diversity comprised 188 species, represented by 191 infraspecies taxa from 7 divisions, 14 classes, 30 orders, 61 families, and 108 genera. According to species diversity, the lakes can be put in the following order: the Yalpuh (78) > Kytay (76) > Kahul (75) > Kuhurluy (55) > Katlabukh (23) > Kartal (16 ist). Bacillariophyta, Chlorophyta and Cyanobacteria lead in species richness. According to habitat preference, planktonic forms made up 45%, benthic forms 24%, epiphytic forms 5%, littoral forms 15%, and eurytopic forms 11%. According to salinity preference indifferent species dominated, and according to pH preference alkaliphilic species prevailed. The Sorensen similarity index and Kendall rank correlation indices for leading families were rather low – 0.18–0.43 and 0.45–0.57 respectively, which is indicative of significant differences among the algal communities in the lakes under study. The algal cell count amounted to 2853–360325 thousand cells · dm–3, the biomass – 0.876–64.113 g · dm–3. According to the quantitative characteristics of planktonic algal communities and Cyanobacteria biomass, the Danubian lakes are eutrophic ecosystems.