Estimating the Biodiversity Level of the Pechora River Delta Freshwater Ecosystems by the Structure of Bottom Communities of Cladocera, Copepoda, and Oligoсhaeta

This study presents an analysis of the species richness and diversity of microcrustaceans (Cladocera, Cyclopoida, and Harpacticoida) and Oligochaeta from the zoobenthos of streams and waterbodies of the Pechora River delta, Korovinskaya Bay and the lakes of its islands, and an adjacent section of the continental Malozemelskaya tundra. We have identified 87 species and forms. It is shown that, due to the heterogeneity of habitats and environmental conditions, the delta is characterized by a specific composition of the fauna of these groups of invertebrates, as well as the specific structure of taxocenoses. According to the Shannon–Wiener (HN), Pielou (E), Simpson (DS), and Whittaker’s (βw) indexes, the highest diversity of the groups is recorded in the streams and waterbodies of the delta; the lowest is in the surveyed area of the Malozemelskaya tundra. Based on our analysis, it is concluded that benthic Cladocera, Cyclopoida, and Oligochaeta are the most effective biodiversity indicators in the Pechora basin in its lower course. This is demonstrated by the cross-taxon correlation data on the species richness of these groups per sample.