IMPORTANCE OF SHALLOW AREAS OF THE UPPER PART OF THE KANIV RESERVOIR IN THE MAINTENANCE OF ITS ICHTHYOFAUNA

Purpose. Determination of the relative number of fish juveniles on biotopes of the upper part of the Kanev reservoir in the aspect of evaluation of these areas in general propagation of ichthyofauna. Methodology. The work is based on data of fish juvenile surveys conducted in the Kaniv reservoir during 2011?2013. Data collection and processing were performed according to generally accepted methods. Fish juveniles were caught using a beach seine made of mill gauze № 7, length 10 m, height 1 m. Relative number of fish juveniles on different sites has been calculated based on the areas of fish nursing biotopes under assumption of the constancy of catchability coefficients. Shannon-Weaver diversity index was used for comparing species diversity of the commercial ichthyofauna of different sites. Findings. The majority of the studied littoral sites of the upper part of the Kaniv reservoir were characterized by sufficiently high indices of biodiversity ― Shannon index values varied within 2,07?3,24 bit./ind. Twenty six species were recorded in the composition of the fish juvenile communities that was 80% of total number of species in the reservoir. It was found that despite a decrease of the relative number of the juveniles of valuable commercial species compared to previous years, the upper part of the reservoir remains the major site for recruitment of commercial fish stock ― 70% of bream, tench, pike, roach, and wels of the Kaniv reservoir are reproduced here. Taking into account the especial value of the upper part in formation of the spawning fund of the reservoir, any hydroenhancement works here should be limited exclusively by navigable channel. Originality. For the first time we quantitatively evaluated (in spatial aspect) the number of fish fauna recruitment in the Kanev reservoir under current state of spawning areas. Practical value. Results of the work will be used during development of a program of enhancement works on spawning grounds of the Kaniv reservoir and development of nature conservation measures when planning hydroenhancement works in littoral zone of the reservoir.