Ichthyofauna of the Bilotserkivskyi lower reservoir on the Ros river

Abstract

The composition of ichthyofauna of Ukraine is changing due to natural processes and the influence of anthropogenic factors in the internal water bodies. Systematic analysis of changes allows controlling these processes and maintaining the diversity of species at a constant level. The purpose of the study was to investigate changes in the composition of the ichthyofauna of the Bilotserkivskyi lower reservoir (Ros River) after the discharge of industrial waste of the Bilotserkivvoda enterprise in 2017 and 2020, which led to the mass death of fish and crayfish. The studies were conducted by catching fish with species identification and a survey of fishermen from November 2016 to October 2020. Additionally, the species composition of fish in this section of the Ros River was considered before the reservoir was created. According to the results of the conducted studies, 24 fish species were identified in 2016, 21 in 2017, and 19 in 2020. Analysing the number of ichthyofauna since the 1960s, it can be concluded that every 10 years the species composition of the ichthyofauna of the Bilotserkivskyi lower reservoir lost about 2-3 species of fish, which is conditioned by the influence of riverbed overlap, industrial activities, uncontrolled and unidentified discharges into the reservoir, etc. After a detailed analysis of the number of ichthyofauna, it was established that by 2016, the following species had disappeared: common dace Leuciscus leuciscus, Dnieper chub P. borysthenicus, ide I. idus, sunbleak Leucaspius delineatus, vimba bream Vimba vimba, crucian carp Carassius carassius, weatherfish Misgurnus fossilis, spined loach Cobitis taenia; in 2017 – species such as gudgeon Gobio gobio, round goby Neogobius melanostomus, tubenose goby Proterorhinus marmoratus; in 2020 – char, ruffe. Quantitative and qualitative restoration of ichthyofauna is possible at the expense of fish from the Protoka River (Rotok). To continue fishing use, it is necessary to settle fish in the reservoir. The practical significance of this study is to determine the species composition of the ichthyofauna for further use of the reservoir for environmental and fishery purposes