This paper presents the results of water quality analysis of the rivers Tamis, Plovni and Stari Begej, using the WQI method, for the time periods 1987-1991 and 1998-2002. It also show the trend of water quality of these water streams for two characteristic time periods, through trend of WQI index.

The sampling of Crnojevica river has been carried out, because of estimation the correlation between main water quality parameters and precipitation impacts, as well as adequate hydrological parameters. An appropriate dynamic sampling has been applied. Continuous pollution of river water has been confirmed, as well as source of the pollution. It is estimated strong correlation of water quality parameters from precipitation quantity and water level, especially for sanitary pollution. Change of quality parameters value is discrete and accidental.

The paper presents the results of investigation of benthic algae of the river Rasina. During April, 2001, it was determined 110 algal taxa from the divisions Cyanophyta, Bacillariophyta and Chlorophyta, which indicate the high biodiversity of algae in this river. With 97 algal taxa, Bacillariophyta is dominant. The community of benthic algae is typical for this kind of aquatic ecosystem during the spring period. Great number of algal bioindicators of highly polluted water indicates the presence of high concentration of organic compounds in this aquatic ecosystem.

Pilot screening of sediment quality on selected stretches of HS DTD and transboundary water bodies in Vojvodina Province (Serbia and Montenegro) was set as an objective of this paper. The results of sediment toxicity tests indicated the necessity for remedial activities of the following stretches: DTD Vrbas - Bezdan - sampling site Vrbas - Canal Banatska Palanka - Novi Becej - sampling site Kajtasovo and Begej - sampling sites Klek and Stajicevo.

Until recently, the wetlands have been destroyed as worthless areas due to the ignorance of their role in the processes that take place in the stream corridors. The paper presents an overview of their roles in the hydrologic cycle, biogeochemical cycling and supporting biodiversity. In addition, their significance in the stream corridor preservation, protection and restoration is discussed. Both, the knowledge of their role in and their significance for the stream corridors, is essential for preventing further imprudent destruction thereof, successful planning and preparation of the stream restoration projects, and the recognition of their possible usage in satisfying human needs.

The paper presents the results of the water quality studies of the Sava river in Belgrade region (Serbia and Montenegro). The investigations were performed in June and September, 2003. The sampling area covered five locations along the 61.5 km of the river course. Studies included the qualitative, quantitative and saprobiological investigations of plankton and macrozoobenthic communities. The bioindicator analysis points to the presence of mild organic pollution indicating thus 2nd and 3rd-2nd class of water quality.

In this paper we have presented the results of the investigations of phytoplankton carried out in the river Old Begey, from April 2003 till February 2004. The presence of 116 algal taxa of which 10 Cyanobacteria, 20 Euglenophyta, 50 Bacillariophyceae, 3 Chrysophyceae, 30 Chlorophyta and 3 Dinophyta was recorded. In the river Old Begey some rarer brackish species Entomoneis alata and Bacillaria paradoxa have also been found. The index of saprobity given on the basis of Pantle-Buck method indicated that the quality of water of the river Old begey belonged to beta-alfa-mesosaprobic category.

One of major direction of algology development in Serbia is completing data about bioindicating values for saprobic system based on the existing list of bioindicators. This work shows the results of several year's investigation of macroalgae in streams that belong to the Danube river watershed. Altogether, 72 taxa belonging to six divisions were found in the investigated streams. They were as follows: Cyanophyta (34 taxa), Rhodophyta (8), Xanthophyta (6), Chrysophyta (1), Chlorophyta (22) and Charophyta (1). Analysis of the list of species found in streams of highland regions of Serbia and the List of Indicatory Species reveals that 50% (36) of the species found have definite indicatory values. This work presents the data obtained for species that are not on the existing lists of indicators.