Relatively dense network of irrigation channels in Vojvodina is exposed to various point and non-point pollutants impacts. Therefore, deposited channel sediments-sludges can be contaminated with high concentration of dangerous and harmful substances such as polycyclic aromatic hydrocarbons (PAH). These sediments could have long lasting harmful effects on environmental status, quality and usability of channel water, and especially on surrounding agricultural soil, where dredged sediments are deposited or scattered. In this paper above mentioned conclusions are illustrated by quality analysis of specific irrigation channels sediments in terms of PAH contents in them.

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.

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).

In the scope of complex water quality analysis of the Bocac reservoir, as well as rivers which flow into and out of the Bocac reservoir (Vrbas, Crna Rijeka) during the period from May to September 2008, the contents and the dynamics of the phyto and zooplankton were analyzed as biological parameters. The qualitative contents of the phytoplankton includes 5 divisions of total 27 taxa from 16 species; the tributaries contain 30 taxa from 19 genuses. The zooplankton (Rotatoria, Cladocera and Copepoda) contain 22 taxa from 16 genuses; the tributaries contain 32 taxa from 19 genuses with huge dominance of the Rotatoria species. By saprobiological analysis, species of oligo and beta mezosaprobiological character previal.

In the paper we presented the effort to collect the recent data clarifying eutrophication as one of the commonest problems of freshwater. The paper includes experience of researchers related to causes of onset and effects of eutrophicational processes on trophic level increase in reservoirs.

Environment is subject of changes in the presence of aquatic pollutants which increase synthesis of biotransformation enzymes and elicitate oxidative stress in aquatic organisms. Monitoring changes of quality of aquatic ecosystems could be based on watching certain biomarkers, like biochemical, molecular and physiological responses of aquatic organisms after exposure to organic toxicants.

Introduction of allochthonous species may have noticeable affects on populations communities of native species, ecosystem, but also could result in socio-economic consequences. Therefore, creating and applying risk assessment protocols of aquatic invasive species is a main step in supression of biological invasions. SBC index is used for estimation of biological contamination.

Content of arsenic in groundwater form south Banat which are used for water supply of local population was determined. 228 wells were analyzed, and for arsenic determination was used atomic apsorption spectrometry - graphite furnace technique (Perkin Elmer Analyst 700). Arsenic is detected in concentrations over 10 microgram/l in several locations: Pancevo (water supply Filter Stanica, Gradska Suma, OB, and in part of water supply Sibnica), Kovin, Dubovac, Idvor, Veliki Gaj, Glogonj, Sefkerin and part of Sakule. The lowest concentrations of arsenic are detected in the territory of Deliblatska Pescara and municipalities of Vrsac and Bela Crkva.