ECOLOGICAL TRANSFORMATIONS OF RIVERINE HYDROECOSYSTEMS AND CURRENT PROBLEMS OF FISHERIES

Abstract

Purpose. To analyze permanent negative effect from transformation of riverine hydroecosystems on fish fauna of Azov-Black Sea Basin. Methodology. Materials on the abiotic parameters of hydro river, according to information received by the regional meteorological stations and their own observations. Industrial situation analyzed by official reports Statefishagency of Ukraine. Findings. The studies demonstrate that there is a gradual process of an increase of the number of components, which virtually exclude the significance of positive results of self-purification by natural way, in water mass of transformed riverine systems. Spontaneous fluctuation of water level, which is caused by volumes of daily discharges, often instantly changes water levels on spawning areas. Fertilized fish eggs is periodically flooded or periodically dried, aeration regime changes that results in mass fish kills at different stages and phases of embryogenesis. Ecological situation of transformed hydroecosystems demonstrates coupling of negative effect of hydrological regime autostaticity in time and space, deterioration of water chemical composition. There is a permanent trend of saturation of water with components, which are not natural that results in doubtfulness of effective reproduction puts in question the possibility of stable state of valuable commercial fish stocks. At the same time, transformed water areas of riverine hydroecosystems have high bioproductive potential, which having its own food resource, is ineffectively transformed into food base for valuable commercial fish species. Against the background of noted changes, the considered water areas lost their suitability of providing effective reproduction. As a consequence, primary valuable fish species form low-yield generations and this is reflected on qualitative indices of commercial fishing. There was found a permanent trend of sufficiently fast change of the ratio of valuable and low-valuable species in favor of low-valuable ones. Originality. Conducted systematic generalization of the impact construction on state fisheries natural reservoirs of Ukraine as an example of the Dnieper. Practical value. The results can be used to develop ways of rational use of Hydrobiological river systems of Ukraine in terms of the transformed flow.

Keywords

• hydroecosystems transformed
• spawning
• bioproduction potential fishing
• semi-anadromous
• communicating kinds of fish fodder resource ihtio-weight