Sasko Lake, with surface area of 3.4 square km and depth of about 8 m, is situated is southwestern part of Montenegro (Serbia&Montenegro), within the hydrosystem of Skadarsko Lake. During 2002 and 2003, seasonal dynamics of main hydrographic, physical, chemical and biological parameters of this ecosystem was monitored. Reference measuring spots are defined, and in these places all future monitoring of system state will be accomplished. Also done are the preliminary batimetric measurements and maps of spaces suitable for development of breeding activities. In order to develop aquaculture as a strategic interest of Montenegro (Serbia&Montenegro), it is necessary to utilize these important potentials and place this important natural resource in full fuction. Included are the list of all fish species living in the lake, as well as the suggestion of species that could be suitable for commercial breeding.

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.

Every country must to concern the biodiversity of flora and fauna, especially in ecosystems rich with endemic and relict species. Such ecosystem is the Lake Ohrid.

In this paper, we present the results from both quantitative and qualitative composition of the Gastropod fauna from Lake Ohrid (profile HBZ-Radozda) with their vertical distribution in littoral and sublittoral region of the lake. The results of our investigations shows some changes in biodiversity and the density of gastropod communities that settle this profile, compared with the investigations made 30 years ago.

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.

In this paper is given the comparative review of investigation of the macrophytic vegetation and ichthyofauna in 4 localities (Grasnica, Gradiste, Veli Dab, and Cerava) from the littoral region of the Lake Ohrid. In the investigated localities are evidenced macrophytic species and fish species as bioindicators for saprobility. Based on the obtained results, it can be concluded that qualitative composition of macrophitic vegetation and ichthyofauna are different and depend from locatities where investigated made.