pdf35

Fisheries Science of Ukraine, 2026; 3(77): 69-91
DOI: https://doi.org/10.61976/fsu2026.03.069
UDC 574.5:597(282.247.32)

Received: 31.07.2026
Received in revised form: 05.09.206
Published: 30.09.2026

Current ecological conditions and the status of aquatic organisms in the reservoirs of the Ros and Molochna rivers of the middle Dnieper basin and the Inhulets and Saksahan rivers of the lower Dnieper basin

I. Mytiai, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0000-0001-6460-7002, National University of Life and Environmental Sciences of Ukraine, Kyiv
M. Ratushnyi, This email address is being protected from spambots. You need JavaScript enabled to view it. , ORCID ID 0009-0009-5850-4010, National University of Life and Environmental Sciences of Ukraine, Kyiv

Purpose. To conduct a comprehensive ecological assessment of the condition of the Ros and Molochna rivers in the Middle Dnieper basin and the Inhulets and Saksahan rivers in the Lower Dnieper basin in the context of their anthropogenic transformation into pond-lake-type water bodies.

Methodology. The study was conducted in the summer and fall of 2019–2023 at eight stations in the Kosiv, Halaykiv, Malooleksandrivka, and Makortiv reservoirs. At each station, two samples were collected for chemical water analysis, as well as for phytoplankton, zooplankton, and macrozoobenthos. Information on fish species composition was obtained through catching juvenile fish conducted by employees of specialized fish farms (STRG) and their fish catch reports.

Findings. A comprehensive study of the ecological conditions and the state of aquatic organisms in the reservoirs of the Ros, Inhulets, and Saksahan rivers in the basin was conducted in 2019–2023. The analysis showed that, in terms of the composition of major chemical elements, the water complies with maximum permissible concentrations (MPCs). At the same time, MPCs were exceeded in the Makortiv Reservoir by a factor of 2.0 for nitrites and 1.86 for phosphorus. The phytoplankton of the studied reservoirs consists of 47–67 species of algae from four phyla: Cryptophyta; Euglenophyta; Chlorophyta; and Bacillariophyta. In terms of abundance and biomass, green algae predominate (809–1,985 thousand cells/dmі, 0.666–1.34 mg/dmі) and diatoms (552–1,612 thousand cells/dmі, 0.046–3.23 mg/dmі). The zooplankton community comprises 26–43 species from three systematic groups: rotifers (Rotatoria), cladocerans (Cladocera), and copepods (Copepoda). According to our data, the macrozoobenthos consists of 6–9 species in the three reservoirs and 22 species in the Markotiv Reservoir, belonging to three systematic groups: oligochaetes (Oligocheta), chironomids (Chironomidae), midges (Ceratopogonidae), mollusks, and larvae of various insects. In total, 16 (Halaykiv), 19 (Makortiv), 26 (Kosiv), and 27 (Malooleksandrivka) species were recorded in the fish fauna. In addition, cultured fish species are present in the reservoirs: carps of the Far Eastern complex.

Originality. A modern comprehensive analysis was conducted of the ecological conditions and the status of aquatic organisms in the reservoirs of the upper Ros and Molochna rivers of the Middle Dnieper River basin, and the Inhulets and Saksahan Rivers of the Lower Dnieper River basin. The ecological structure was determined based on the species composition and abundance of phytoplankton, zooplankton, macrozoobenthos, and ichthyofauna communities. A close relationship was demonstrated between phosphate concentrations and the abundance and biomass of cyanobacteria.

Practical Value. The results obtained can be used in the development of measures to increase the fish productivity of these water bodies and in the development of operating regimes for mini-hydroelectric power plants.

Keywords: hydrochemistry, phytoplankton, zooplankton, macrozoobenthos, ichthyofauna.

REFERENCES

  1. Song, X., Li, Q., Long, Y., Zhang, J., Wang, H., Yang, B., & Xiao, J.  (2025). Impacts of Continuous Damming on Zooplankton Functional Diversity in Karst Rivers of Southwest China: Different Hydrological Periods and Implications for Karst Reservoir Management. Diversity, 17(7), Art. 478. https://doi.org/10.1051/KMAE/2017043
  2. Blabolil, P., Řнha, M., Ricard, D., Peterka, J., Prchalovб, M., Vaљek, M., Čech, M., Frouzovб, J., Jůza, T., Muљka, M., Tuљer, M., Draљtнk, V., Sajdlovб, Z., Љmejkal, M., Vejřнk, L., Matěna, J., Boukal, D. S., Ritterbusch, D., & Kubečka, J. (2017). A simple fish-based approach to assess the ecological quality of freshwater reservoirs in Central Europe. Knowledge and Management of Aquatic Ecosystems, 418, Art. 53. https://doi.org/10.1051/KMAE/2017043
  3. Jurik, Ľ., Hъska, D., Halбszovб, K., & Bandlerovб, A. (2015). Small water reservoirs – sources of water or problems? Journal of Ecological Engineering, 16, 22–28. https://doi.org/10.12911/22998993/59343 
  4. McCluney, K. E., Poff, N. L., Palmer, M. A., Thorp, J. H., Poole, G. C., Williams, B. S., Williams, M. R., & Baron, J. S. (2014).  Riverine macrosystems ecology: sensitivity, resistance, and resilience of whole river basins with human alterations. Frontiers in Ecology and the Environment, 12(1), 48–58. https://doi.org/10.1890/120367
  5. Agostinho, A. A., Gomes, L. C., & Santos, N. C. L., & Ortega, Jean C. G. (2016). Fish assemblages in neotropical reservoirs: colonization patterns, impacts and management. Fisheries Research, 173, 26–36. https://doi.org/10.1016/j.fishres.2015.04.006
  6. Baumgartner, M. T., Piana, P. A., & Baumgartner, G., & Gomes, L. C. (2020).  Storage or Run-of-river Reservoirs: Exploring the Ecological Effects of Dam Operation on Stability and Species Interactions of Fish Assemblages. Environmental Management, 65, 220–231. https://doi.org/10.1007/s00267-019-01243-x
  7. Chittora, D., Meena, M., & Barupal, T., & Swapnil, P. (2020). Cyanobacteria as a source of biofertilizers for sustainable agriculture. Biochemistry and Biophysics Reports, 22, Art. 100737. https://doi.org/10.1016/j.bbrep.2020.100737
  8. Belletti, B., Garcia de Leaniz, C., & Jones, J., et al. (2020). More than one million barriers fragment Europes rivers. Nature, 588, 436–441. https://doi.org/10.1016/j.jenvman.2020.110408
  9. Birnie-Gauvin, K., & Nielsen, J., Frandsen, S. B., Olsen, H.-M., & Aarestrup, K. (2020). Catchment-scale effects of river fragmentation: a case study on restoring connectivity. Journal of Environmental Management, 264, Art. 110408. https://doi.org/10.1016/j.jenvman.2020.110408
  10. Barbarossa, V., Schmitt, R. J. P., Huijbregts, M. A. J., Zarfl, C., King, H., & Schipper, A. M. (2020). Impacts of current and future large dams on the geographic range connectivity of freshwater fish worldwide. Proceedings of the National Academy of Sciences (PNAS), 117(7), 3648–3655. https://doi.org/10.1073/pnas.1912776117
  11. Bednarek, P., & Mołoniewicz, L. (2023). River fragmentation in the northern Sandomierz Basin (SE Poland). River Research and Applications, 39(8), 1497–1505. https://doi.org/10.1002/rra.4168
  12. Costa, F., & Vieira, A. (2023). Stream barrier removal: are new approaches possible in small rivers? The case of the Selho River (Northwestern Portugal). Hydrology, 10(8), Art. 163. https://doi.org/10.3390/hydrology10080163
  13. Albrecht E., Lukkarinen, J., Hakkarainen, M., & Soininen, N. (2023). Hydropowering sustainability transformation: policy frames on river use and restoration in Finland. Fennia - International Journal of Geography, 201(1), 47–64. https://doi.org/10.11143/fennia.120946
  14. Darre, E. (2024). Evaluating the readiness for river barrier removal: A scoping review under the EU nature restoration law. Science of The Total Environment, 959, 1–13. https://doi.org/10.1016/j.scitotenv.2024.178180
  15. European Parliament, & Council of the European Union. (2000). Directive 2000/60/EC of the European Parliament and of the Council of 23 October 2000 establishing a framework for Community action in the field of water policy. Official Journal of the European Communities, L 327, 1–73. http://data.europa.eu/eli/dir/2000/60/oj
  16. Hrebin, V. V., Khilchevskyi, V. K., & Stashuk, V. A., et al. (2014). Vodnyi fond Ukrainy. Shtuchni vodoimy. Vodoskhovyshcha i stavky: dovidnyk [Water Fund of Ukraine. Artificial Water Bodies. Reservoirs and Ponds: A Reference Guide]. Interpres LTD. http://elib.chdtu.edu.ua/e-books/4110
  17. Khilchevskyi, V. K. (2009). Hidroekolohichnyi stan baseinu richky Ros [Hydroecological state of the Ros River basin]. Nika-Tsentr.
  18. Khilchevskyi, V. K. (2021). Suchasna kharakterystyka poverkhnevykh vodnykh obiektiv Ukrainy: vodostoky ta vodoimy [Modern characteristics of Ukraine’s surface water bodies: watercourses and water bodies]. Hidrolohiia, hidrokhimiia i hidroekolohiia [Hydrology, hydrochemistry, and hydroecology], 1(59), 17–27.
  19. Khilchevskyi, V. K. (2020). Narys istorii hidrokhimii poverkhnevykh vod v Ukraini [An Outline of the History of Surface Water Hydrochemistry in Ukraine]. Hidrolohiia, hidrokhimiia i hidroekolohiia [Hydrology, hydrochemistry, and hydroecology], 2(57), 5–87.
  20. Kutsokon, Yu. K. (2004). Doslidzhennia rybnoho naselennia baseinu richky Ros [Study of the fish population of the Ros River basin]. Visnyk Kyivskoho natsionalnoho universytetu imeni Tarasa Shevchenka. Seriia: Biolohiia [Bulletin of Taras Shevchenko National University of Kyiv. Series: Biology], 42–43, 34–36.
  21. Kutsokon, Yu. K. (2008). Aboryhenna ikhtiofauna baseinu Dnipra pid zahrozoiu (na prykladi r. Ros) [Native ichthyofauna of the Dnieper basin under threat (case study: Ros River)]. In Dniprovskyi ekolohichnyi korydor [Dnieper ecological corridor]. Wetlands International Black Sea Program, 94–99.
  22. Kutsokon, Yu. K., Tsyba, A. O., Podobailo, A. V., & Pankov, A. V. (2016). Suchasnyi vydovyi sklad rybnoho naselennia livykh prytok Serednoho Dnipra: Supoiu ta Trubezha [Current species composition of fish populations in the left-bank tributaries of the Middle Dnieper: the Supiy and the Trubizh]. Naukovyi visnyk Chernivetskoho universytetu. Biolohichni systemy. Naukovyy visnyk Chernivetsʹkoho universytetu. Biolohichni systemy [Scientific Bulletin of Chernivtsi University. Biological Systems], 8(2), 228–232.
  23. Buzevych, I. Yu., & Symon, M. Yu. (2023). Strukturni pokaznyky ta dynamika promyslovykh uloviv ryb dniprovskykh vodoskhovyshch [ Structural parameters and dynamics of commercial fish catches of Dnieper reservoirs]. Fisheries Science of Ukraine, 4, 17–24. https://doi.org/10.61976/fsu2023.04.017
  24. Didenko, A., Volikov, Y., Gurbyk, A., Kruzhylina, S., Buzevych, I., & Bekh, V. (2024). Population dynamics and feeding ecology of the western tubenose goby (Proterorhinus semilunaris) in the Stugna River, Dnieper River basin, Ukraine. Oceanological and Hydrobiological Studies, 53(1), 61–70. https://doi.org/10.26881/oahs-2024.1.07
  25. Bielikova, O., Čiampor, F., Jr., Zaloilo, O., & Čiamporovб-Zaťovičovб, Z. (2024). Species identification of Rutilus genus in Ukrainian water bodies: Data from the analysis of cytochrome oxidase subunit I (COI) and cytochrome b (cyt b) mitochondrial DNA genes. In Proceedings of the 5th International Congress on Applied Ichthyology, Oceanography and Aquatic Environment (HydroMediT 2024) (pp. 503–507). University of the Aegean.
  26. Romanenko, V. D., & Medovnyk, D. V. (2017). Vydova ta ekolohichna kharakterystyka ikhtiofauny malykh richok urbanizovanykh terytorii [Species composition and ecological characteristics of the fish fauna of small rivers of urban territories]. Hidrobiolohichnyi zhurnal [Hydrobiological Journal], 53(4), 3–12.
  27. Romanenko, V. D., Zhukynskyi, V. M., & Oksiiuk O. P., et al. (2001). Metodyka vstanovlennia i vykorystannia ekolohichnykh normatyviv yakosti poverkhnevykh vod sushi ta estuariiv Ukrainy [Methodology for Establishing and Using Environmental Quality Standards for Inland Surface Waters and Estuaries of Ukraine].
  28. Marenkov, O., Kurchenko, V., Nesterenko, S., Chernyavska, A., & Hruzdieva, O. (2023). Assessment of the quality and ecological status of the Saksagan river in the context of drinking water and fishery purposes. Journal of Chemistry and Technologies, 31(4), 901–916.  https://doi.org/10.15421/jchemtech.v31i4.291632
  29. Kobiakov, D. O., & Novitskyi, R. O. (2025). Transformatsiia hidrolohichnoho rezhymu serednoi techii r. Bazavluk ta yii vplyv na rybne naselennia [Transformation of the hydrological regime of the middle reach of the Bazavluk River and its impact on its fish population]. Fisheries Science of Ukraine, 4, 105–128. https://doi.org/10.61976/fsu2025.04.129
  30. Mytiai, I., Khomych, V., Degtyarenko, E., Shevchenko, P. H., & Martiusheva, O. O. (2023). Impact of mini-hydropower on the chemical composition of water and phytoplankton of the reservoirs of the Forest-Steppe of Ukraine. IOP Conference Series: Earth and Environmental Science, 1254(1), 012001. https://doi.org/10.1088/1755-1315/1254/1/012020
  31. Khalturyn, M. B., Klymkovetskyi, A. A., & Shevchenko, P. H. (2022). Vydova riznomanitnist ikhtiofauny vodoim kompleksnoho pryznachennia lisostepovoi zony Ukrainy za baseinamy richok [Ichthyofauna species diversity in multipurpose water bodies of the forest-steppe zone of Ukraine by river basins]. Fisheries Science of Ukraine, 2, 3–15. https://doi.org/10.15407/fsu2022.02.003
  32. Klimkovetskyi, A., & Khalturyn, M. (2022). Ichthyofauna of the Bilotserkivskyi lower reservoir on the Ros river. Animal Science and Food Technology, 13(3), 20–27. https://doi.org/10.31548/animal.13(3).2022.20-27
  33. Arsan, O. M., Davydov, O. A., Diachenko, T. A., Yevtushenko, M. Yu., Zhukynski, V. M., Kyrpenko, N. I., & Yakushyn, V. M. (2006). Metody hidroekolohichnykh doslidzhen poverkhnevykh vod [Methods of hydroecological research on surface waters]. LOHOS.
  34. Aleksiienko, V. R., & Podobailo, A. V. (1998). Metodychni vkazivky do vyvchennia ikhtiolohii (rozdil: morfometrychnyi analiz ryb) [Methodological guidelines for the study of ichthyology (section: morphometric analysis of fish)]. Kyivskyi universytet.
  35. Roman, A. M. (2016). Metod zastosuvannia sachka yak znariaddia dlia zboru ikhtiolohichnoho materialu [Method of using a dip net as a tool for collecting ichthyological material]. In Suchasni problemy teoretychnoi i praktychnoi ikhtiolohii: materialy IX mizhnar. ikhtiol. nauk.-prakt. konf. (Odesa, 14–16 veres. 2016 r.) [Modern Problems of Theoretical and Practical Ichthyology: Proceedings of the IX International Scientific and Practical Conference on Ichthyology (Odesa, September 14–16, 2016)]. (pp. 228–229). TES.
  36. Kaltenbach, H. M. (2026). Statistical Design and Analysis of Biological Experiments. Springer. https://doi.org/10.1007/978-3-032-15065-3
  37. Welham, S. J., Gezan, S. A., Clark, S. I., & Mead, A.  (2024). Statistical Methods in Biology. Routledge / Taylor & Francis. https://doi.org/10.1201/b17336
Home2026№ 3/2026 (77)2026_03-069_091-Mytiai