Biotesting in the Assessment of Environmental and Toxicological State of Water Bodies in Lower Don River Basin

The toxicity of river water in the Lower Don basin was studied using biotesting with different biological objects. Water taken from most examined reaches of the Don and its tributaries was shown to exert toxic effect on crustaceans, algae, protozoa, and Rotifera.     

Analysis of the effect of megalopolises on water quality in surface water bodies by ecological-toxicological characteristics

Data of long-term observations of Roshydromet and the studies of the authors’ studies of hydrochemical, hydrobiological, and bioassaying characteristics and appropriate publications in the areas of megalopolises—the cities of Rostov-on-Don and Novosibirsk are analyzed. Similar and distinctive characteristics of water quality by these ecological-toxicological characteristics are identified; trends in the long-term year-to-year variations in water quality are established, criteria and characteristics reflecting the effect of cities on water bodies in their territory are determined. The identity of some chemical-toxicological criteria and the characteristics of the influence of cities in southern Russia and Siberia on water bodies suggest that they can also be used in urban area in other regions. The Lower Don is used as an example to show that water pollution by metals is mostly due to wastewater discharge, while water pollution by petroleum products and sulfates has no direct relation to that.     

Tendencies of long-term changes in water quality of water bodies in the South of Russia

Based on analyzing long-term (1968–2010) national monitoring data from Rosgidromet and other agencies as well as on research results for the Lower-Don and Kuban’ river basins, we identified observation posts on water bodies with a stably high pollution level and gave a characterization of the spatiotemporal tendencies of its changes. Long-term changes in water quality are exemplified by an alternation of periods of increasing and declining pollution; its level showed a decrease from the period 1980–1990 to the end of the last decade.     

Present-day characteristics and trends of long-term changes in ecological and toxicological conditions of the Tsimlyansk Reservoir

The analysis of ecological and toxicological conditions of the Tsimlyansk Reservoir and of trends of long-term variations of hydrochemical, hydrobiological, and biotesting parameters is carried out on the basis of long-term data of Roshydromet regular observations (1984?C1991) and authors?? studies (1990, 2006?C2007). It is revealed that, according to the complex of chemical parameters, the water pollution level decreased by the end of the period and is relatively low at present, although the pollution is of stable nature and the toxic and carcinogenic compounds are discovered in the water and in bottom sediments. The most dangerous display of the reservoir eutrophication is a ??bloom?? of algae characterized by the prevalence of blue-green algae (Cyanophyta) amounting to 100% of the total biomass in some samples; the species being able to discharge the toxins to the water (Aphanisomenon flos-aquae, Microcystis aeruginosa, Anabaena flos-aquae) often prevail. During biotesting, the samples of water and bottom sediments in a number of cases exerted a toxic effect on the water organisms and, most likely, the toxicity increases with time. Although different parts of the reservoir differ considerably in ecological and toxicological parameters, an ecologically unfavorable situation emerged in the reservoir ecosystem due to the pollution, eutrophication, and toxicophication.     

Intra-waterbody processes in large reservoirs of southern Russia (pollution,eutrophication, toxification)

Long-term data from Rosgidromet and research results were used in comparing the chemistry condition of the southern reservoirs (Tsimlyansk, Proletarsk and Veselyi) to reveal that the ecologo-toxicological indices and characteristics of such intra-waterbody processes as pollution, eutrophication and toxification differ substantially. In the first place, the differences apply for the hydrochemical regime and mineralization as well as for individual biological indices. Common to the reservoirs are a stable (chronic) character of chemical contamination (in spite of its relatively low level), and a long-lasting presence of stable organochlorine pesticides in the composition of contamination, and a decline in biodiversity. The Tsimlyansk and Veselyi reservoirs show a similar seasonal dynamics of the phytoplankton, and a predominance of blue-green algae in the phytoplankton community. An unfavorable factor for the ecosystem of the Tsimlyansk reservoir is represented by annually recurring water bloom, with a large-scale occurrence of toxic species of algae, and by an increase in toxicity of natural water (toxification).     

The Role of Biotic and Abiotic Component of the Aquatic Ecosystems in the Formation of Ecological Trouble in Tsimlyansky and Manychsky Reservoirs

Water Resources - The relative importance of indicators of biotic and abiotic components of water ecosystems of the Tsimlyansky and the Manychsky (Proletarian and Veselovsky) reservoirs in the...