The analysis of the frequencies of chromosome breaks and gaps on the pike - Esox lucius L. individuals from different locations collected in two consecutive years, were showed the highest values that were above the level of spontaneous (under the level of 3%) changes. Frequences of changes in fish Esox lucius L. were higher than the level of the presumed critical zone (3.0-3.5%) at locality of Danube by Visnjica and within the zone by Grocka. In consecutice years in river Tamis by Pancevo, both obtained values of chromosomal changes in this fish also were above the critical zone. Physicochemical water analyses were shown high level of organic contamination and concentration of phenols above MDK values for the 1st, 2nd water categories which argued obtained cytogenetic results. The localities obviously has a risk of being permanent or periodical contaminated with genotoxic agents.

This work shows the effects of opening the Itebej sluice gate on the metals content of the water and sediment of the Begej canal. A deterioration in water quality resulted, in particular on the first day after opening of the sluice gate, when high concentrations of Zn, Cr, Cu and Pb were detected. The metals content of the surface sediments across the canal at Klek had significantly higher concentrations of Pb, Cr, Zn, Cu and Hg five days after the opening, whereas there were no obvious changes at Itebej. From the metals content of the suspended sediment it can be concluded that the increase in metals contents occurred one day after opening the sluice gate.

During field research of phytocenic characteristics of the river Moravica flow and the influence of anthropogenic pollution, the presence of the following hydro-phytic biocenoses has been established: Floating macrophytes ass. Lemnetum minoris Oberd. 1960 and submersed macrophytes Myriophyllo-Potametum Soo 1934. Based on physicochemical water analyses and ecological indexes, these biocenoses belong to transitional group of mesotrophic and eutrophic biocenoses which develop in water highly saturated with mineral substances (highly polluted waters). Biocenosis Lemnetum minoris with differentiating species Lemna minor matches - meso - saprogenic waters. These biocenoses grow in both mid and upper river flow.

Water quality conditions of the Tatarnica canal are considered in this paper. Tatarnica is also the main canal of Begec drainage system, which is situated about twenty kilometers from Novi Sad on the west. Water quality of this canal is important, beside others, because its inflow into Danube is near Begecka Jama, which is representative of natural garden with special ecological asset. Results of investigation on this locality during three years are analyzed and presented. According the most relevant water quality parameters from predominant number of samples, water belongs to required category. Sometimes, a bad water quality are recognized, usually when organic pollution was appear, which influence higher value of BOD5.

The results of sediment quality monitoring gathered during the period 2002-2008 were processed and shown in the current work to assess the overall sediment quality in Vojvodina watercourses regarding heavy metals content. Since Serbia does not have legislation for sediment quality, Canadian and Dutch sediment criteria were used for evaluation of sediment quality. The elevated concentrations of heavy metals in Vojvodina watercourses are a consequence of the discharge of untreated or partially treated industrial and municipal wastewaters, but also of the corosion of metal structures and constructions (Cu, Zn) as well as the influence of difussion sources, principally agriculture (Cd, Cr, Hg) and transport (Pb).