ECOLOGICAL ASPECTS OF TRIMATODOSE DISTRIBUTION OF THE ICHTHYOFAUNA OF THE MLYNIV RESERVE

Abstract

The article presents the results of the study of the ichthyofauna of the Mlyniv Reservoir for the presence of diplostomosis, postdiplostomosis and opisthorchiasis caused by helminths. After all, the presence of invasive diseases reduces the quality of fish products and can harm human health. Mlyniv Reservoir is located on the Ikva River at a distance of 52 km from the confluence with the Styr River in the Rivne region. Annual reports of the Rivne State Regional Laboratory of Veterinary Medicine in the Rivne Region for 2014–2020, as well as monitoring data of specialists from the Institute of Epizootology of the Ukrainian Academy of Sciences were used to analyze the dynamics of trematode dose in fish in the Mlyniv Reservoir. Methods of clinical and epizootological examination, laboratory methods and statistical data processing were used. During 2014–2020, 227 specimens of fish were treated for trematodes in Mlyniv Reservoir. Pathological and microscopic examinations were mainly performed. Positive results were found annually. The analysis of the acts of epizootological examinations of the Mlyniv Reservoir, which were systematically carried out by veterinary specialists of the region, showed that in 2017–2020 the disease of postdiplostomosis was registered annually. The dependence of the influence of climate change, and especially air temperature on the spread of trematodes was also obtained. Water quality assessment is performed according to the Methodology of water quality assessment according to the water pollution index (WPI). Nitrite nitrogen, BSC5 and ammonium nitrogen have the most negative effect on the rate of SLE. The highest multiplicity of exceeding the MPC of ammonium nitrogen was in 2016 (3 times), nitrite nitrogen in 2019 (15 times), and BSC5 in 2016 (5 times). Although in recent years, the MPC began to exceed phosphates (multiplicity exceeding 17.5). If we compare the quality of surface waters of the Mlyniv Reservoir and the number of positive results for the presence of helminths in the studied fish samples, we do not see a clear relationship.