Liashenko V. Diagnostic monitoring of river bodies ecological state in terms of zoobenthos and biotesting of bottom sediments

The dissertation is devoted to the complex analysis of river ecosystems surface water quality and establishment of their ecological condition. For the first time, long-term diagnostic monitoring of surface water quality was performed using biological indication and biological testing methods. The dissertation includes surface water quality assessment performed by studying benthic macroinvertebrate communities; carried out in conjunction with establishing the bottom sediments contamination by biological testing on plant and animal test organisms. The following widely used biotic indices were calculated: the Trent Biotic Index, the Belgian Biotic Index and the Biological Monitoring Working Partly Index. To assess the level of organic pollution, the Goodnight Whitley and the Zelinka Marvan saprobity indices were calculated. The species diversity on benthic invertebrates was assessed by the Shannon index, the similarity of species composition was assessed by the Jacquard index with further cluster analysis. To estimate the bottom sediments pollution level biological testing with the following test organisms was performed: Lactuca sativa L., Allium cepa L. and Daphnia magna Strauss. The study was conducted for four model river ecosystems Danube, Uday, Vorskla and Ros` rivers. The work represents result of fourteen year study. The dissertation is based on the material including 445 samples of benthic macroinvertebrates and 240 samples of bottom sediments taken during 2007-2019 at 22 observation stations. The total number of macrozoobenthos species identified during the study is 126. For the Danube River 89 species of benthic macroinvertebrates were registered with the total abundance from 16,600 to 38,000 specimens per square meter. For the Uday River 58 species of benthic macroinvertebrates were registered with the total abundance from 7330 to 13745 specimens per square meter. For the Vorskla River 26 species of benthic macroinvertebrates were registered with the total abundance from 29 to 70 specimens per square meter. For the Ros` River 22 species of benthic macroinvertebrates were registered with the total abundance from 13 to 266 specimens per square meter. Surface water quality assessment performed by biotic indicators of benthic macroinvertebrate communities indicates the predominance of "good" quality class among all studied river ecosystems. Estimation of the bottom sediments pollution level performed by biological testing on plant and animal test organisms indicates the predominance of "low" pollution level among all studied river ecosystems. It was shown for the first time that integrated using of surface water quality biological indication and bottom sediment pollution level biological testing is a promising area of modern environmental monitoring. Long-term gradual changes in surface water quality are registered with the help of biological indication by benthic macroinvertebrate communities on the example of Danube and Uday rivers. On the other hand short-term fluctuations in pollution level of water ecosystems are registered with the help of bottom sediment toxicity biological testing on plant and animal test organisms. The suitability of the established reference values from the Udai River benthic macroinvertebrate communities for determining the ecological state of other rivers of Ukraine was shown. Results of the dissertation can be used to find solution of the reference conditions determining problem for water bodies. This task is a necessary step for the implementation of surface waters monitoring Ukraine state programs.