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.

Due to drainage as a significant measure of land reclamation, large part of Vojvodina Province (Serbia) affected by excessive water could become an agricultural land. The stability of ecosystems could be decreased by degrading the biodiversity. Additionally, Vojvodina has cca 6% of sylvan landscape but according to documents of spatial arrangement planning that area should be 14%. In order to solve this problem the implementation of biological measure could increase drainage efficiency by improving biodiversity and increasing the area covered by sylvan landscape, which is likely to do using biological measures of drainage on low productivity areas and buffer strips along canal network.

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.

Jegricka water body is part of the Main Drainage Channel System. The whole length of Jegricka (65 km, catchment surface 60.380 ha) is located in south part of Backa, Vojvodina Province. This highly modified water flow has become protected area since 2005 due to its specific natural features - diversity and uniqueness of biotic features, especially for birds and plants. In July 2008 survey of freshwater macroinvertebrates was conducted in order to assess water quality and conservation potential according to biotic characteristics according to conservation criteria within SERCON (System for Evaluating Rivers for Conservation) method. The aim of this paper was to evaluate the importance of macroinvertebrates as indicators of conservation potential of Jegricka water using SERCON. Results of analyses of species composition of freshwater invertebrates fauna showed presence of 12 higher taxonomic groups. Within these groups, 23 families were present at eight RHS river sections along investigated part of Jegricka water body. Togheter with SERCON based conservation criteria for macroinvertebrate, two types of biotic indices Biological Monitoring Working Party (BMWP) and Average Score Per Taxon (ASPT) were calculated in order to assess water quality. Results of the survey showed that Jegricka water body belongs probably to moderately polluted water type according to biotic indices. Results of conservation criteria Naturaless showed that observed and expected faunas are similar. Low values of SERCON family richness criteria based on whole length of water body indicate that Jegricka has low conservation potential, and that adequate rehabilitation measures should be considered in the future.

The paper presents aquatic macroinvertebrate community composition at six investigated localities of the Veliki Rzav river (Serbia). Sampling were carried out during 2005. Characteristics of the macroinvertebrate community with field data were used to estimate the status of the river.

Water quality monitoring of surface waters encompasses the watercourses of the river basins of Una, Vrbas, Bosna, Drina, Ukrina and the direct Sava basin. Apart from comprehensive analyses which demand determinations of physical - chemical characteristics, as well as the ihtiofauna composition, special emphasis is given to the analysis of the macrozoobenthos. As a part of all water ecosystems, benthic invertebrate serve as a reliable indicator of the quality and changes of the environment, due to a series of advantages in relation to other communities. Most of the aquatic habitats, especially flowing waters of good quality of water and benthic state, enable various of benthic invertebrates communities with moderate formation of species within the overall number of the present individual species. This kind of communities react to possible changes in the community composition (abundance and macroinvertebrata composition).

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).

The allochthonous aquatic macroinvertebrates and fish species represent a potential danger to the autochthonous diversity. Hydrobiological research conducted during 2008 under the development of medium-term programmes for fishery improvement in Serbia, showed that some of the allochthonous aquatic macroinvertebrates and fish species have expanded their areals to a new water habitats. Artificial lakes (reservoirs) proved to be very suitable for the population of allochthonous species, where they become numerous most of the time. New habitats were found for allochthonous aquatic macroinvertebrates species: shells (Dreissena polymorpha, Sinanodonta woodiana) and American crab (Orconectes limosus), and for fish species for Micropterus salmoides. It was also determined that fish populating is a good way to inhabit and expand new habitats with allochthonous species of aquatic organisms.

The Bovan reservoir is built on the river Moravica, near Aleksinac (Serbia), primarily for the purpose of water supply. Investigations were carried out during the period of June 2005 to December 2006, with the aim to determine the quality of water, the composition, spatial and time dynamics of communities of microorganisms. The results showed that according to the total number of bacteria in the water reservoir Bovan fall into the category of clean water by Amrazena (1976). By Kohl (1975), water reservoir Bovan belongs to class 2. Summer-time give maximum water characteristics the 2nd-3rd class. Index T/H varies from category to category moderately contaminated clean water. Values heterotrophs percentage representation in the total number of bacteria indicating the great burden of water organic matter.

Sulfonamide antibiotics can enter agricultural soils by fertilisation with contaminated manure. While only rough estimations on the extent of such applications exist, this pathway results in trace level contamination of groundwater. Therefore, we studied the transport of three sulfonamides in leachates from field lysimeters after application of a sulfonamide-contaminated liquid manure. In a 3-year period, the sulfonamides were determined in 64% to 70% of all leachate samples at concentrations between 0.08 to 56.7 µg L−1. Furthermore, sulfonamides were determined in leachates up to 23 months after application, which indicated a medium- to long-term leaching risk. Extreme dry weather conditions resulted in highest dislocated amounts of sulfonamides in two of the three treatments. Furthermore, soil management such as tillage and cropping affected the time between application and breakthrough of sulfonamides and the intra-annual distribution of sulfonamide loads in leachates. Although the total sulfonamide leaching loads were low, the concentrations exceeded the limit value of the European Commission of 0.1 µg biocide L−1 in drinking water in more than 50% of all samples. Furthermore, the medium-term mean concentration of the sulfonamides ranged from 0.08 and 4.00 µg L−1, which was above the limit value of the European Commission in 91 out of 158 samples. Therefore, sulfonamides applied to soils in liquid manure under common agricultural practice may cause environmental and health risks which call for a setting up of more long-term studies on the fate of antibiotics.