Rehabilitation of fish fauna in the Pripyat hydroecological corridor from hydroecology positions

Ichthyecological criteria for assessing the status of river catchments of the Pripyat Hydroecological Corridor (HEC) are defined, their matrices are developed, as well as the limiting factors of impact on ecosystem functioning have been studied in order to find ways for rehabilitation of fish fauna of this significant natural object. The quantitative and qualitative status of fish fauna of the Pripyat HEC was assessed based on the cameral processing of the material collected in expeditions and interviews of recreational fishermen. The hydrological regime of the Pripyat HEC, using the yearbooks of the hydrometeorological services of the Polissya Region from 1922 to 2005, has been investigated. Processing of these data was performed with a mathematical program created in Delphi. The aquatic environment was considered as a black box with incoming and outgoing information, which was measured by 50 parameters according to a comprehensive environmental classification of water quality. It was proved that the rehabilitation of the Pripyat HEC is urgently needed. Changes in the ecosystem of the Pripyat HEC were assessed using a spatial biomarker; a sharp deterioration in the habitat and conditions of fish reproduction were noted. A spatial biomarker of the surface water state was developed and used to assess the conditions for the reproduction of native fish fauna in the Styr R. and Horyn R. within the Pripyat HEC. The presented formalized functioning scheme of the Pripyat HEC shows that its development was extremely irrational. A comparative analysis of the state of the river ecosystem ichthyocenosis in the Styr-Horyn fish-restoration complex relative to non-transformed catchments was made. A comprehensive index of the ecosystem state of the studied catchment was introduced and calculated by the ratio of its actual parameters to their optimal characteristics. The main trends of the rehabilitation of fish fauna in the Western Polissya area of the Pripyat HEC are formulated; the basic scheme of its implementation is presented. The effectiveness of using a spatial biomarker and a catchment approach has been demonstrated.