Observations of the state of chemical pollution of surface waters were carried out in 101 rivers, 15 reservoirs, 7 lakes, and 1 channel at 195 spots.
An analysis of the quality of surface waters shows that the content of heavy-metal compounds is still high in almost all basins, especially in the basins of the Danube, Dniester, Southern Bug, Dnieper, Siversky Donets rivers, as is the content of compounds of nitrogen, petroleum products and phenols ( Table 4.3) – in some basins. Almost all water bodies under observation are polluted, and some are highly polluted. The Mountain Crimea rivers are in a fairly good state, though in this basin high concentrations of ammonium nitrogen were observed in the Uskyut and Taraktash rivers in the course of 1998.
About 900 cases of severe pollution of surface waters by 14 ingredients were registered in 1998 in 80 water bodies (64% of those under observation).
There were 240 cases of severe pollution in the rivers of the Dnieper Basin (Dnieper, Goryn, Desna, Sula, Teteriv, Vorskla, Desna, Samara, Ingulets rivers); in the Siversky Donets Basin (Siversky Donets, Udy, Kazennyi Torets, Bakhmut, Lugan, Bilenka rivers) 205; in the Dniester Basin (Dniester, Tysmenytsia, Opir, Stryi rivers) 65; in the Azov area rivers (Kalmius, Kalchik, Bulavin, Molochna) 64; in the Western Bug Basin (Western Bug, Poltava, Luga rivers) 48; in the Danube Basin (Danube, Latorytsia, Vicha) 38; and in the Southern Bug river there were 30 cases.
In the cascade of the Dnieper reservoirs 197 cases of severe pollution were registered, 127 of these in the Kyiv and Kaniv water reservoirs. These rivers and water reservoirs are the most polluted ones. No essential improvement of the quality of surface water in hydrochemical figures were observed as compared with the previous years; however, there is a tendency towards a decrease of the pollution level. A certain decrease in the content of ammonium nitrogen and nitrite nitrogen was observed in the Danube and Dniester basins. The amount of copper compounds has been reduced in the water of the Dnieper reservoirs and the Western Bug Basin rivers.
At the same time an increase of the concentration of copper compounds was observed in the water of the Southern Bug Basin rivers, as was the case with zinc in the Dniester Basin rivers.
State of Hydrobiocenoses
The state of surface waters as to hydrobiological indicators was observed in 49 rivers and 10 reservoirs, one lake at 101 spots.
A complex assessment of the state of the ecosystems in terms of hydrobiological indicators has shown anthropogenic ecological stress in 71% of the water bodies being monitored; the rest of the water bodies were characterized by an ecological impact by elements of regression ( Table 4.4 ). Planktocenosis of the Stryi River was on the verge of regression, while the planctonic group in the Latorytsia River was in the state of regression.
An improvement of the state of the ecosystems was observed in recent years in separate water bodies. Development of blue-green algae in the reservoirs of the Dnieper cascade has considerably decreased, which evidences a decrease of biogenic substances entering the water bodies. As compared to 1997 the state of planktocenoses has improved in the Ingul, Mokra Moskovka and Kalmius rivers and in the Kremenchuk reservoir.
Deterioration of conditions for plankton cenoses was observed in the Kaniv, Dnieper and Kakhovka reservoirs and in the Mokra Plotva and Molochna rivers.