This paper presents results of measuring the contents of certain bio-indicators in samples of digestive gland and lung of mussels (Mytilus galloprovincialis). The results were obtained in the framework of the Program for monitoring ecological status in Montenegro during the 2009 and 2010 year. Biomonitoring program was conducted in accordance with the LBS Protocol (Protocol on the Protection of the Mediterranean Sea against pollution from land-based sources and land activities) and the criteria MED POL Programme (Mediterranean Pollution Control), which is compliant with the requirements of the European Environment Agency (EEA) and has established a system of reporting and data exchange with the EEA. The program includes the analysis of biomarkers in Mytilus galloprovincialis (Lamarc, 1819) (mussels), and dynamic sampling is 2 times a year (March and September). In order to assess the spatial distribution and temporal trends of pollution, followed by the response of various biomarkers presented at two positions in the coastal waters of Montenegro (Dobrota and Bijela) and three positions in Slovenia (bays Piran, Strunjan and Koper). Biomarker responses showed no difference between the positions of the different ecological status.

Concentration of lead (Pb), lame (Cr), copper (Cu) and cadmium (Cd) were detrmined in Cystoseira algae collected from the Montenegrin mediolittoroal, during the spring 2007. Samples of three species of Cystoseira algae (C. amentacea, C. barbata and C. compressa) were analyzed in order to have information on bioaccumulation of these elements and possibility to use these algae as biomonitors for heavy metal pollution. The data obtained for heavy metals were similar with other area of Mediterranean Sea, with exception for significantly higher concentration of copper, on Budva location.

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.

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.

Samples for phytoplankton investigations were collected in annual period (September 2003 - August 2004) in the Kotor and Risan Bay. Mean-values percentage contribution of the group diatoms (Bacillariophyceae) through the annnual period were from 79.70% to 86.50%. Species Skeletonema costatum, Pseudo-mitzschia delicatissima, Leptocylindrus minimus and Chaetoceros affinis, were the main edificators of diatom population. Densities of these species were from 10**5 to 10**6 cells/cubic dm. These values are characteristic of eutrophic and extreme eutrophic area. It is needed one permanent monitoring to protect this part of Boka Kotorska Bay negative consequences.

Researches of the Zelengora natural lakes during 2008 were performed in Orlovacko, Kotlanicko and the Lake Donje Bare. Water quality analysis of natural lakes of Zelengora were based on preliminary examination of basic physical and chemical parameters, as well as microbiological parameters. In the scope of biological examinations, phytoplankton, zooplankton and benthic fauna were determined. Due to the lack of data on biodiversity of examined natural lakes and whole area of National park Sutjeska results obtained in this research could only represent the first step toward further examinations, as well as the nature and biodiversity preservation in the Republic of Srpska.

In this paper the results of preliminary microbiological investigations of the canal Nadela water quality, done in order to determine level of pollution, are presented. Bacteriological analysis included the monitoring of quantitative composition of the organotrophs, presence of some physiological groups of bacteria and total number and fecal coliforms. Beside of that, level of water phosphatase activity and chlorophyll a concentration as important parameters of waterstate, were determined. Obtained results indicated low quality of the canal Nadela water and overload by organic matter, that cleary reflected negative influence of pollutants presents in that area.

There are some water reservoirs on the territory of Zajecar district area (Serbia). Their purpose and time of building are very different. It is also different the organic matter production in those reservoirs. Water reservoirs for supplying with drinking water are very specific because the increased of organic products makes some difficulties in process of refinement reservoir water to drinking water. In this paper we are trying to explain, taking the reservoir Grliste for the example, if the biomanipulation exerts on water quality in the reservoirs.