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.

In the scope of complex physical-chemical and biological water examination of Bocac water reservoir, the river Vrbas and trbutaries Ugar and Crna Rijeka, examination of standard microbiological indexes of water quality (aerobic organotrophs at 22-26 deg C and 37 deg C, total colliforms and colliforms of fecal origin) was performed during 2002 (March-November). Number of examined microbiological parameters was mainly in the scope of the 2nd water category (beta-mesosaprobic water) with worse water quality in upstream part of the reservoir. Ugar tributary had the best water quality, while Crna Rijeka had the worst status with obvious anthropogenic influence.

The activities acid, neutral and alkaline phosphatases, as well as total phosphatases activities were estimated in the water of the Lake Ohrid tributaries Sateska, Koselska, Velgoska and Cherava. The same analyses were performed in the littoral zones where the tribitaries enter Lake Ohrid. The study covers the period from September 2000 to October 2001. The obtained results show that different types of phosphatase effect different extracellular activities, an observation which is probably the result of differences in the location within the cells and the way of intracellular synthesis.

There have been given research results of quantitative and qualitative indices of communal and industrial waste waters of Nis. The research was carried out by the Institute "Jaroslav Cerni" (group of authors) and JKP "Naissus" (4) with the goal of defining as reliable parameters as possible in order to draw up plans for a central wastewater cleansing plant in Nis, as well as several necessary treatments of the industrial waste waters. There have been presented quantities, load and expected load of the total waste water, basic characteristics of urban and natural recipient, waste water influence on the river Nisava and needed degree of cleansing.

In scope of complex physical-chemical and biological examination of water quality of the Bocac lake, the river Vrbas and tributaries Ugar and Crna Rijeka, examinations of phytoplankton and zooplankton were performed during 2002 (March-November). In qualitative structure of phytoplankton 7 division were registered, with 93 taxa from 49 genera in total. In warmer period extreme domination have fire algae (Pyrrophyta). In zooplankton structure (Rotatoria, Cladocera, Copepoda) 78 taxa were registered from 36 genera, with distinct domination of Rotatoria group. According to saprobiological analysis species of olligo- and beta-mesosaprobic character are prevailing.

Bacteriological examination have been carried out within the comprehensive hydrochemical and hydrobiological investigation of river Koselska during 2002. The aim of investigations is to confirm condition of bacteriological communities and water quality of river Koselska. The results of investigations shows pollution by organic matter. In order to prevent further eutrophication processes, certain measures of river water protection and conservation should be undertaken. Also, the regular monitoring of water quality should be established.

During the period February 1999 - February 2000 samples of water taken monthly from the area before the outflow of river Crn Drim from the Lake Ohrid, in purpose of qualitative and quantitative investigation of phytoplankton community. During the period of investigation, the phytoplankton community was characterized by forms of Cyanophyta, Bacillariophyta, Chlorophyta, Chrysophyta, Pyrrophyta and Euglenophyta. Qualitative analysis indicated that algae of the division Chlorophyta and Bacillariophyta are dominant in the phytoplankton, while the results of the qualitative analysis showed that forms of Bacillariophyta are dominant. Seasonal dynamics of phytoplankton is characterized by autumnal and winter domination of Bacillariophyta, spring maximum of Chrysophyta and summer domination of Pyrrophyta. The total number of algae varied between 1500-95,700 ind/l in August and February 2000, respectively.

The paper gives the contribute to analyses of the problem of Crnojevica river (Montenegro, Serbia&Montenegro) water pollution. The analyze surround measurement the next parameters: pH, conductivity, oxygen balance, sanitary parameters, content of different form of phosphorus. These measurements are carried out over five sampling series, at the seven stations, including underground flow rate in the Obod cave. Our estimations are confirmed the continuity of the Crnojevica river pollution, by municipality and strain water from Cetinje urban area. Nutrients, especially phosphates, from the pollution emission, attend conditions (together with many natural factors) for production biomass quantity. The opposite processes, the inhibition processes, exist. Phosphorus in the water attends increase level of the water pollution (over increase eutrophication degree), so the water is out of the legal class, because its usage is limited.

The results of the regular water quality monitoring in the river Moraca (Montenegro, Serbia&Montenegro), are presented in this paper. Thirty samples have been processed from six measuring station along the river's flow. The data relevant quality indicators (conductivity, dissolved oxygen, chemical oxygen demand, five days biochemical oxygen demand, ammonia, nitrites, nitrates, and phosphates) have been processed in the light of the existing regulations. It has been confirmed that the water quality, from the physical-chemical aspect, varies depending on the measuring location and the hydrological situation. The evaluated condition shows that the water quality gets worse, in the period of the five years, on the profiles of downstream places from Podgorica. The level of decrease gets to deviation from the requested A2CII class. It is particularly shown in the changes of the values for the nutrients and the relevant indicators of the organic pollution (dissolved oxygen, five days biochemical oxygen demand, chemical oxygen demand), which we presume can be consequence of the effect of the algaes during the period of the "low level water".

The river Crnojevica is a subject of lasting manny years physicochemical and microbiological investigations, which show worring pollutants presence into the water current. This work represent preliminary investigations of Crnojevica river water algal flora (phytoplankton and phytoperiphyton), carrying out over summer period of 2004. Aim of the investigation was to point, based on algal analysis, as reliable indicators of water quality and ecological status of an aquatorius, the need to protect the river from permanent communal and industrial waste water pollution. The hyperproduction of phytoplankton in the investigation period was stated, but it varys along the current, in accordance with efluent inflow. On the base of saprobiological analysis of phytoplankton, determinated water quality was in class 2, till the worse was noted at T2 measure place, on the inflow place of Rijeka Crnojevica settlements sewage.