A study of zooplankton in tundra lakes of the pechora river delta (north-eastern european Russia)

Abstract

© 2020 International Multidisciplinary Scientific Geoconference. All rights reserved. For the Arctic region of Russia, an inventory of the biodiversity of aquatic ecosystems for the purpose of environmental monitoring is extremely urgent. Global warming for terrestrial ecosystems manifest as changes in the distribution of individual species and assemblages, in the timing of important life-cycle events, and in abundance and community structure. Zooplankton communities in the Northern lakes are highly diverse and thus perform a variety of ecosystem functions. The most important role of zooplankton is as the major grazers in the freshwaters, providing the principal pathway for energy from primary producers to consumers at higher trophic levels. We studied zooplankton communities of 11 small tundra lakes in the Pechora River delta. The samples were collected during the summer expedition in 2018 from the territory of the Nenets State Nature Reserve. A total of 50 zooplankton taxa were identified, of which the most frequently occurring ones were rotifers (Conochilus unicornis, Kellicottia longispina, and Keratella cochlearis), cladocerans (Bosmina (Eubosmina) longispina, Holopedium gibberum, and Chydorus sphaericus), and immature copepods. In zooplankton of the studied lakes, rotifers (22 species) and cladocerans (17 species) were dominant. The most diverse families by species composition were: Brachionidae, Trichocercidae, Chydoridae and Cyclopidae. The biomass of zooplankton was made up mainly by cladocerans. The abundance was formed by cladocerans and rotifers. According to the Pantle-Buck index modified by Sladecek, the studied tundra lakes can be characterized as oligosaprobic. The Shannon-Wiener species diversity index values (with an average of 1.89±0.16) vary from 0.08 to 3.15. This index classifies the waters as a β-mesotrophic type.