Habitat and Features of Development of Plankton Communities in the Unique Round Lakes of the Nadym River Basin (Western Siberia, Russia)

This article discusses the morphometry, hydrochemistry, zooplankton, and macrophytes of three unique round lakes in the Nadym River basin (Western Siberia, Yamal-Nenets Autonomous Okrug (YNAO)). Their significant depths, weak lakeshore angularity, zero water color, and predominance of sulfates in the ionic composition are atypical for the northern taiga lakes of Western Siberia. Coastal aquatic vegetation is characterized by extremely low species richness with the dominance of Sparganium angustifolium, which is an indicator of highly transparent ultrafresh oligotrophic waters. Dominant complexes were formed in planktonic communities represented by 1–2 species with a high level of dominance. According to the level of development of total zooplankton biomass, the lakes are ultra- and oligotrophic.