Article

In this paper are presented the researches of the fish populations qualitative composition in Lake Prespa, Lake Ohrid and Lake Skadar. In those three lakes as result of negative anthropogenic impact there are changes in fish biodiversity (with more presence of alochtonous species). In this way, unfortunately autochthones populations of fishes (which are rich by endemic and relict species) are endangered.

By reason of inserting news species, the fish populations are endangered, especially the populations of particular zoographically significant species. So, it is necessary to proceed the procedure to their inserting in the Red list of endangered species.

The abundance of the fish populations in the three biggest lakes in the Balkan Peninsula is in dependence from of their different altitudes, surfaces and depths. Also, the qualitative composition of the fish populations in those lakes depend from the different physic-chemical conditions, biological communities (phytoplankton, zooplankton, bottom fauna), and especially from the macrophyte vegetation.