During spring of 2005, referent monitoring of the chemical quality of surface waters and sediments in some protected areas in Vojvodina (Serbia) was conducted as a supplement to the Regular monitoring program. The aim of the study was to establish the chemical quality of surface waters and sediments regarding nutrient content. It is shown that the water quality satisfies the criteria of the 1st/2nd class according to our legislation, with the exception of the Ludos location, which showed a contamination with nitrogen matter in water and sediments. With regard to the contamination of water with phosphorus, almost all locations may be considered as potentially problematic.

Within the pollutant analysis in sediments the total organic carbon (TOC) content is determined, as well as nutrients such as nitrogen and phosphorus. In addition to this form carbon may be present as elemental or inorganic ones, as the crucial issue for sample preparation. Total phosphorus content was determined after sample digestion with sulphuric and perchloric acid. Organic nitrogen values were determined according the Kjeldahl method. Concentrations of TC, TOC, TIC, total P, organic N and total N in river Tisza sediment samples from sites Martonos, Novi Becej and Titel during 2004 and 2005 were presented.

In the frame of the project Revitalization of the Big DTD Canal and preparation for introducing modern wastewater treatment plants for the towns and industry in the Backa region, an all-inclusive program has been prepared for monitoring quality and quantity of water in the Big Canal and pertaining lateral canals. The paper presents results obtained for contents of nutrients (N and P) that indicate a poor quality of the Canal water, especially in the segment from the triangle to the hydrological node Vrbas. In many cases, measured concentrations of nitrogen and phosphorus were several times higher than maximal tolerable levels, so that it is necessary to undertake urgent measures with the aim of preventing further degradation of the Canal water, and eventually its revitalization.

Nitrogen and phosphorus contents in water, sediment and shoots of Phragmites communis Trin, and Typha latifolia L., as possible indicators of trophic state were used in the area of the Bardaca fish-pond. The results of total nitrogen and phosphorus contents during growing season indicate the hypertrophic state of waters in all locations.