In order to determine the dynamic of biomass of stoneworts from Lake Ohrid as a function of the trophic state of the water, we collected samples from four different localities. The localities Sveti Stefan and Mazija, were characterized by oligotrophic state of the water, while the other two Grasnica and Daljan were characterized by eutrophic-mezotrophic water quality. The stoneworts samples were taken from 4-5 different depths from each investigated locality. The results of our investigations have shown that higher trophic level of the water from the littoral region of the localities Grasnica and Daljan (especially in the points of inflow of river Grasnica and Daljan) decreases the amount in stoneworts biomass compared with the biomass of stoneworts collected from the first two localities that characterizes oligotrophic character of the water.

In the period October 2001 through November 2002 in six series parallely with physico-chemical and hydrobiological analyses, the content of photosynthetic pigments was determined in algae in the region of flow-through reservoirs of "Djerdap 1" and "Djerdap 2" on the profiles of Smederevo, Ram, Veliko Gradista, Donji Milanovac, Tekija, Kladovo and Radujevac. The samples were taken by a pump from the river midstream at the depth of 1-0 m (composite sample), while in the vegetation period April, June and September, the samples were taken at the depth of 5 m. The peak concentration of chlorophyll-a, the biological indicator of trophic condition, was recorded in the month of April in the Smederevo profile (30.2 mg/cubic meter) at the depth of 1-0 m. The lowest values of chlorophyll-a in all studied cycles were recorded in the Radujevac profile (below the dams) with the mean annual value of 1.8 mg/cubic meter. Chlorophyll-c occurs as the subdominant photosynthetic pigment. Values of chlorophyll-c were higher than chlorophyll-a in the month of June on the Donji Milanovac profile in the analysed sample taken at the depth of 5 m. Higher values of chlorophyll-b were recorded in the course of the vegetation period in the month of June on the profiles of Smederevo, Ram, Veliko Gradiste and Donji Milanovac at the depth of 1-0 m.

Processes like QMS (Quality management systems) and EMS (Environmental management systems) consist of series of procedures/elements, among which are operative or working procedures. One of these procedures is control of waste waters from the Aluminium Plant in Podgorica, Montenegro (Serbia&Montenegro). This procedure controls the order of activities, the responsibility, the input and output documents, with the exclusive aim to measure the effects of protection of surface and underground waters and to review the EMS of the company for the waste waters.

In order to protect the water current of the river Tisza, the fermentation industry AD "Fermin" Senta, Serbia (Serbia&Montenegro) has built the biological waste water treatment plant for the waste water discharged from the yeasts producing factory, which started the production in 1982. So far the output of the plant can be definied as not equal to the designed capacity level. The results of four effect analyses have been shown in the tabelar survey as well as the technological block scheme of both the current and suggested solution projects. The suggested solution basically contains phase separation in anaerobic procedure and the intraduction of tertial treatment method (nitrification and denitrification). The paper presents a contribution to optimal technology of industrial waste water treatment.

According to Water Plan of the Republic of Serbia the area between Kovin and Dubovac was marked as a possible place for water source for regional water supply of towns and industry of South Backa Region (Serbia). Commencement of underwater coal exploitation was at the beginning of 1990's in the Danube riparian zone near Dubovacka Ada. Potential influence of long-term underwater coal exploitation from "Kovin" trial coal pit on Dubovacka Ada on quality and quantity of groundwater that will be extracted from regional water source is analysed in this article.

The fenced hunting area "Crni Lug" near Progar (Serbia, Serbia&Montenegro), included swamp tracts that have been drying. A natural environment of free game has changed over the last fifteen years. The unfavourable hydrological trend is explained by the antropogenic factor active in the hunting area and beyond it. The prevailing hydrogeological situation is interpreted and steps for rehabilitation of marshes are recommended. One of the emphsized goals is the supply of good water for animals throughout the year. Favourable hydrogeology and construction of adequate facilities in the hunting area will suffice for the revival of all activities related to water: flood control, agriculture, water supply, and hunting as a particularly profitable activity.

Available data on zooplakton research in Adriatic sea show that coastal and open waters of south Adriatic are the zone of most available and richest area in Adriatic sea. Shallow waters along the shore and the Boka Kotorska Bay are characterized by a monotony of faunistic content, while, by contrast, high values of biomass are caused by abundance of a small number of estuary-neritic species. Open waters of South Adriatic are characterized by holoplankton, while waters of Boka Kotorska Bay are characterized by meroplankton. Zooplankton of open sea shows a high diversity of fauna but a small biomass in part of open water above the geatest depths, and significantly high values of biomass in epipelagic waters above the continental shelf.

Comparative analysis of results obtained in hydrobiological research conducted to date indicates that relatively few water reservoirs in Serbia have been subjected to complex hydrobiological investigations. Apart from the fact that hydrobiological investigations are now performed on only a small number of water reservoirs in Serbia, they are moreover inadequately coordinated, which is especially evident in differences of procedural approaches employed. With adoption of the principles of modern limnology and wider use of new criteria for water classification (m WQI for instance), the current state of hydrobiological research constitutes a basic for the development of comprehensive program of planned continuous studies of water reservoirs in Serbia resulting in their rational and successful management.

The town Pozarevac water supply is endangered due to groundwater quality degradation on the only remaining water source Kljuc 1. Nitrate content presents critical parameter (MCL in potable water is 50 mg NO3/l) with values in cumulative samples up to 40-45 mg NO3/l, locally up to 70-100 mg NO3/l. Rapid water quality degradation on water source in the last few years is a consequence of the surrounding activities which have influenced on quality deterioration, excessive groundwater extraction, off-line of water source Meminac, unfavourable hydrologic conditions etc.

During 2001, water from river Cerava and from the littoral where the river flow into lake Ohrid, were examined. Bacteriological analysis included ecological and sanitary aspekt of water state. Heterotrophic, proteolytic, amylolytic and phosphomineralizing bacteria, most probable number of total coliforms (MPN) and presence of Escherichia coli and Clostridium perfringens were determined. The results of investigations shows organic and faecal pollution and permanent negative anthropogenic effects.