Production of zoobenthos in various areas of the Dnipro (Zaporizhzhia) reservoir

The paper presents the results obtained during the study of zoobenthos found in various reservoir areas located at a considerable distance from each other and influenced by various environmental factors. The purpose of the study was to analyze the species diversity of benthos using the Shannon, Menchinik and Goodnight indices, distribution of benthic groups and abundance of hydrobionts. The reservoir environment is influenced by the abundance of hydrobionts and their functional features. Zoobenthos plays a key role in hydroecology of the reservoir, therefore, the study of its species composition is an important issue. As part of the study, diversity and abundance of zoobenthic groups were analyzed in various areas of the reservoir. Zoobenthos of the reservoir is represented by five systematic groups that include 104 species of various origins at different stages of development with the dominant larval stage. The species diversity is influenced not only by external environmental factors, but also by the profundal and littoral zones of the reservoir. There are numerous biotopes with muddy bottom layers formed by the increased amounts of organic matter in the areas. The water quality was determined using the Mayer and Menchinic indices, and the species diversity of hydrobionts was measured using the Shannon index. The biotopes near Viyskove village was found to be a conditionally clean area as the water quality there complied with the standards and the registered number of benthic organisms was significantly higher compared with other groups. Particular attention should be paid to the areas located near the Dnipro Pipe and Dnipro Metallurgical Plants that discharge industrial wastewater with significant levels of pollutants of various origins; these areas are extremely poor in hydrobionts and the water there does not meet the quality standard. They also have poor species diversity, represented by one or two species of invertebrates. In view of further changes in aquatic and terrestrial ecosystems, global climate changes, further development of light and heavy industries and their impact on the ecosystem of the Dnipro (Zaporizhzhia) Reservoir, we came to the conclusion that continuous monitoring studies should be performed on all groups of aquatic organisms as well as hydrochemical characteristics of water and trophic links in the formation of the reservoir forage base.