Redudance rivers are basic hydrographic problem in area of Radjevina. Their appearance to associate for most rivers in the confluence of Likorda river and have character of season. Using method of quantity index the rivers of this region are classified in special hydrological classes. On the basis of this typology the possible models for solution of this problem are given.

Water samples for chemical and microbiological analyses as well as material of the water community to be considered in the assessment of qualitative and quantitative composition of phyto- and zooplankton, and bottom fauna were take on 30 May 2001 at two profiles. Judging by the most of the analyzed chemical parameters, with the exception of BOD5 and oxygen saturation values indicating class 2, water of the Bovan lake accumulation belongs to the 1st class of water quality. According to the presence of heterotrophic bacteria, water was characterized as class 1-2 (after Kohl). Also, 6 groups of phyto- and 4 groups of zooplankton were recorded. Relative abundance and qualitative composition values of plankton show that saprobic index ranged from 1.54 to 1.98 pointing out oligo-beta, namely beta-mesosaprobic character of the accumulation. Saprobic index when oligochaetes were considered amounted up to 3.6 (alfa-mesosaprobic water).

Thermal waters represent an unused natural potential of Serbia. A possible way of utilizing this resource is to carry out the initiative that has been underway over the past several years to use certain thermal waters for the rearing of some allochthnous thermophilic fish species, the most famous among them being the group Tilapia (fam. Cichlidae), authochthonous in Africa and Asia. The analysis of basic physico-chemical properties of the Ovcar Banja (Ovcar Spa) thermal waters (the bed of the Zapadna Morava river, Western Serbia) indicates the possibility of their utilization for this purpose.

In this paper, there were discussed the results of ecological investigation of the Montenerin part of the Adriatic sea during the period 1996-2003. Evaluation of the sea-water quality was done in the coastal sea. The importance of multiannual ecological investigations was emphasized, too.

In the last few years, in Montenegro there were positive movements into fulfilling the principles of sustainable marine fishery, primarily throught introducing the Law on Marine Fishing and its rules. Institure of Marine Biology in Kotor, Montenegro, in cooperations with the Ministry for Agriculture, Forestry and Water Management of the Republic of Montenegro, works on undertaking of the measures that may ensure optimal regulation of fishing. These measures were based on scientific research, particularly on the estimates of parameters of population dynamics, biomass and maximum biologically sustainable utilization of economically important species on Montenegrin coast.