ASSESSMENT OF THE STATE OF FISH POPULATIONS ICHTHYOPHAGES AND METHODS OF MAINTENANCE OF THEIR RESOURCES ON THE EXAMPLE OF THE NATIONAL PARK “BRASLAV LAKES”

Abstract

On the example of four lakes of the Braslav Lakes National Park, the dynamics of the commercial fish catch, including large ichthyophages — pike and pike perch for the period from the moment of the formation of the park to the present is considered. It was found that during the specified period the resources of pike and pike perch, which by the time the park was created, tended to decrease in almost all water bodies, in subsequent years stabilized and slightly increased. The populations of pike and pike perch are characterized by medium or low abundance, a fairly high growth rate, and within the analyzed group of lakes, a relatively small fluctuation in the growth rate. It was found that the resources of pike are exploited more intensively, which does not give the possibility of their significant increase. The main reason is the selective impact of recreational fishing. The resources of pike perch are in a satisfactory condition and correspond to the production capabilities of the reservoirs. The effectiveness of the fish-breeding activities in terms of the growth of the stocks of the analyzed fish species is discussed. It is assumed that stocking is most effective in order to increase the resources of pike, while technical reclamation is most effective in order to increase the resources of both pike and pike perch.