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Purpose. Analysis of obtained data and integration of previous hydroecological data and statistical information for the preparation of scientific and biological rationale and development of the regime for rational and environmentally sustainable fishery exploitation of the Khrystoforivske Reservoir. Methodology. Hydrochemical and hydrobiological methods of sampling, laboratory and statistical processing of the material were used in the water area of the Khrystoforivske reservoir of the Bokovenka river during comprehensive studies in the summer of 2022. We studied the hydrochemical parameters of the water body, species composition, quantitative parameters of the main groups of hydrobionts, including fish forage organisms (macrophytes, phytoplankton, zooplankton, zoobenthos), the biological productivity of the reservoir was measured based on the main groups of hydrobionts. To determine the state of the main groups of hydrobionts, two samples of phytoplankton, zooplankton and zoobenthos were collected. Macrophytes were studied, water samples were taken from different parts of the water body for hydrochemical analysis. The biomass of phytoplankton was calculated based on the biomass of standard volumes of algae, the biomass of zooplankton – by multiplying the quantity of organisms by their individual weights, zoobenthos – by weighing individual groups of hydrobionts on torsion scale and recalculating and summing up. The reservoir feeding capacity was assessed by the quantitative development of zooplankton according to known classifications. Findings. The main parameters of the chemical composition and properties of the water of the Khrystoforivske reservoir, which condition the bioproductivity and fish farming performance, were determined: pH, content of dissolved gases, organic substances, biochemical demand of O2, nutrients content, as well as general mineralization and hardness, concentration of the major ions. According to the hydrochemical classification, water is bicarbonate type II and is referred to fresh water. The degree of water saturation with easily-oxidizable organic matter has decreased over the past 15 years and is within standards for aquaculture. Considering all environmental and sanitary parameters, water of the Khrystoforivske reservoir is characterized by fair or average quality, it is eupolytrophic. The water characteristics indicate that the fishery exploitation at the reservoir during previous Special Commodity Fish Farming Regimes (SCFF) (1996–2021) has produced no adverse effects on the general ecological and sanitary condition of water. Aquatic phytocoenoses of the Khrystoforivske reservoir are represented by associations of submerged and aerial-aquatic plants, with a total area of 5.2 hectares. The total production of aquatic plants is 36.245 tons. The phytoplankton of the reservoir includes 51 species of algae (six groups). In terms of quantity, small-celled Cyanoprokaryota predominated (about 70%). Diatoms, green and euglenic algae dominated in biomass. In 2022, the average biomass of phytoplankton in the Khrystoforivske reservoir was up to 1.80 g/m3, the total annual production of phytoplankton reached 201.06 tons. In total, 16 species of organisms have been identified in the zooplankton of the reservoir: Rotatoria, Cladocera and Copepoda. The average abundance of zooplankton in the reservoir was 31,390 ind./m3, and its average biomass reached 0.41 g/m3. The value of primary production of zooplankton is 123.9 kg/ha, and the total stock in the reservoir is 7.687 tons. The fish food supply in terms of zooplankters in the Khrystoforivske reservoir are low. The reservoir itself, based on the group of zooplankton, can be referred to fishery class III (the lowest class). The bottom fauna is represented by 40 taxonomic groups of invertebrates. The Chironomidae and Oligochaeta assemblies are most developed in terms of density, but molluscs dominate in biomass. There is a general trend towards a decrease in the quantitative parameters of macrozoobenthos, in particular, Mysidacea. The average biomass of soft benthos (2.17 g/m2) and the average biomass of the entire zoobenthos (33.62 g/m2) indicate that the reservoir preserves its fishery potential due to macrozoobenthos. The primary production of zoobenthos of the Khrystoforivske reservoir is 130.2 kg/ha. The total stock of zoobenthos is up to 8.072 tons. The values of the fish food supply are quite high due to zoobenthos in the reservoir, the water body in terms of benthos biomass is referred to fishery class II (medium productive reservoirs). The obtained comprehensive data on the food supply of the Khrystoforivske reservoir indicate the availability of sufficient bioproduction potential for its continuous effective fish-farming on the basis of the special commodity fish farming regime. Originality. For the first time in the last 10 years, comprehensive data on the food supply of the Khrystoforivka reservoir, which is used in special commodity fish farming regime (SCFF), have been obtained and analysed. Practical value. The results obtained are of practical importance for the development of scientific and biological rationale for fish farming in the Khrystoforivske Reservoir.

Purpose. Assessment of the dynamics of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region. Methodology. The study on heavy metal contents in water, bottom sediments, and hydrobionts (fish) was conducted at various water bodies (Dnipro-Donbas hydraulic canal), fish ponds (ponds of PrJSC “AgroSoyuz”, PrJSC “Petrykivsky Rybhosp” and PE «Agrofirma «Nakhodka»), and multipurpose reservoirs (Dnipro reservoir, Sholokhivske reservoir) in Dnipropetrovsk region from 2015 to 2024. The determination of heavy metal concentrations (Pb, Cd, Mn, Cu, Fe, Ni, Zn) was carried out at the laboratory of the Research Center for Biosafety and Environmental Monitoring of Agricultural Resources of Dnipro State Agricultural and Economic University. The metal content was analyzed using atomic absorption spectrophotometry. The heavy metal contents were measured in four fish species (European perch, roach, Prussian carp, common carp). Sampling, data processing, and statistical analysis were conducted according to standard hydrochemical, hydrobiological, and ichthyological methods. The heavy metal contents were determined in fish muscles. Water quality was assessed according to general requirements and standards for fishery water bodies. Findings. The heavy metal contents in ecosystems of water bodies of different purposes was determined. In the sediment of ponds of PrJSC “AgroSoyuz” and PrJSC “Petrykivsky Rybhosp”, the heavy metal contents were significantly higher than in water or fish body: manganese within 41.24–68.43 mg/kg, cadmium – 0.32 mg/kg, lead 1.50–4.90 mg/kg (for ponds of PrJSC “AgroSoyuz”); manganese – 29.73 mg/kg, cadmium – 0.54 mg/kg, lead 5.72 mg/kg (for recreational pond of PrJSC “Petrykivsky Rybhosp”). For the water of these ponds, which is used for aquaculture, an excess of the content of some heavy metals – Mn, Zn, Cd - was recorded, and for the pond of PrJSC “AgroSoyuz” also Cu. Exceeding the normative heavy metal content for pond water of PE “Agrofirma “Nakhodka” was not noted. The content of some heavy metals in the water of the upper part of the Dnipro reservoir (Cu, Fe) did not meet the fishery norms. At the same time, the heavy metal contents in water and fish of these water bodies does not exceed the fishery standards for water used for fishery purposes. The heavy metal contents in the water of the upper part of the Dniprovske Reservoir (except for the Samara Bay) corresponded to fishery standards. The water in the Dnipro-Donbas hydrotechnical canal was characterized by high levels of heavy metals. Of the 6 investigated heavy metals, the maximum allowable concentrations were not exceeded only for lead (0.40 mg/dm3) The heavy metal contents in C. carpio muscles (juveniles and table fish) in different ponds of PrJSC “Petrykivskyi Rybhosp” (nursery and fattening) corresponded to fishery standards during the three years of the study (2011, 2015, 2016). In the Sholokhivske reservoir, the zinc content in C. gibelio muscles was 46.50 mg/kg, slightly exceeding the maximum allowable concentrations. Exceedances of copper and lead content were not noted. For fish from the Dnipro reservoir, the content of most heavy metals was elevated. In the meat of pelagic roach (R. rutilus), only copper content was within the normal limits (1.56 mg/kg), while all other 6 heavy metals exceeded the maximum allowable concentrations. In the meat of benthophagous Prussian carp (C. gibelio), elevated levels of accumulation of heavy metals were observed for manganese, iron, lead, and nickel, while zinc, copper, and cadmium content were within the standards. In the meat of European perch (P. fluviatilis), the highest content of heavy metals was observed for iron (80.54 mg/kg), with elevated levels observed for manganese, zinc, lead, and nickel. The obtained results indicate that the hydroecosystem of the Dniprovske reservoir, unlike other water bodies in the region, is significantly polluted with heavy metals. This is adequately reflected in the levels of heavy metal accumulation in the organisms of fish from different ecological groups - pelagic herbivores, benthophagous bottom-feeders, and predators. Originality. For the first time, the content of heavy metal accumulation in water, bottom sediments, and fish of water bodies of different purposes in Dnipropetrovsk region has been carried out over several years (2015–2024). Practical Value. The obtained results have theoretical and practical importance for the preparation of scientific-biological justifications for the fishery use of water bodies of various purposes in the region. Continuous monitoring of the heavy metal contents in hydrobionts is necessary to ensure food safety and the quality of raw materials and food fish products.

Purpose. Based on the author’s materials, to carry out a preliminary assessment of ecological and economic losses caused to the fisheries complex of the Kharkiv region as a result of military actions. Methodology. Field studies on water bodies of the Kharkiv Region, which were affected by military actions, were conducted. Public data of the State Agency of Land Reclamation and Fisheries of Ukraine in the Kharkiv Region (2021–2023) were used. The following research methods were used during the assessment of the ecological consequences and economic losses caused to the aquatic biological resources of water bodies of the Kharkiv region: analytical – collection of information from official sources of enterprises and institutions carrying out economic activities, control and monitoring of water bodies; geoinformation – assessment of the actual hydrological regime of water bodies; identification of the spatial location, measurement of quantitative and qualitative characteristics of water areas formed after the reservoirs drying-up; hydrobiological – determination of fish species and other hydrobiont composition; statistical – for qualitative and quantitative assessment of commercial ichthyofauna and the economic damage inflicted to the fishery; forecast –assessment of the potential transformation of the species biodiversity of the ecosystem in time under different conditions of further development of the water sector of Ukraine. Findings. The impact of military actions on the conditions of existence of aquatic biological resources in the Oskil and Pechenegi reservoirs, on the functioning of special commercial fish farms, the production of aquaculture products, and the development of industrial and recreational fishing in the region has been preliminarily assessed. The calculation of economic losses for aquatic bioresources of water bodies of the Kharkiv region was carried out. Originality. For the first time, a preliminary assessment of losses for the fisheries industry (including commercial, recreational fishing, aquaculture) of the Kharkiv region due to military actions was carried out. Practical value. The obtained results have important and multifaceted practical value, in particular they can be used for: assessment of environmental damage caused to Ukraine as a result of military actions; rational management of water and fisheries management due to restoration of water ecosystems exposed to military impact; development of recommendations on restoration of ecosystem services; spread of social awareness about the post-war environmental challenges of the future; making decisions about investments in natural resources and the use of ecosystem services.

Purpose. Based on authors’ materials, to develop an original method of collecting and processing information to determine the quantitative and qualitative characteristics of recreational fishing in water bodies of Ukraine. Methodology. The work is based on the quantitative and qualitative analysis of ichthyological material obtained from anglers’ catches in the Kakhovka, Dnipro (Zaporizhzhia), Kamianske, Pechenezhsky reservoirs and their tributaries in different seasons of 2003–2022. Data collection and processing were carried out according to generally accepted methods. The statistical material was processed using MS Excel. Findings. Based on the analysis of modern recreational fishing as a factor affecting the structural and functional characteristics of ichthyofauna, the main trends of studies for the development of measures for the regulation of this type of nature use have been determined. Methodological recommendations have been prepared for the collection of factual data on the parameters of recreational fishing in water bodies of Ukraine. An approach to determining the parameters characterizing the visitation of the reservoir by recreational fishermen, species composition and quantitative characteristics of catches has been proposed. Typical forms of information collection have been proposed. Originality. For the first time for Ukraine, an original method of collecting and processing information for the assessment of qualitative and quantitative parameters of recreational fishing has been developed. Practical value. The proposed methodological approaches will be used to record the quantitative and qualitative characteristics of recreational fishing in water bodies of Ukraine both by scientists and by bodies implementing the state policy in the field of protection and exploitation of aquatic biological resources.