Threats to salmon and endangered fish species in Tysa river basin within trans Carpathian region (review)
Abstract
Establish ways of creating, thoroughly investigate the threats and their level of salmon and endangered fish species Tysa River Basin within Zakarpattia region. Rate of change, diversity, distribution, the proportion of individual species, to the distribution of geographic elements on the principle of zoning and depending on environmental conditions. The study of threats to salmon and endangered species of fish in the river Tysa carried tributaries and in areas watercourse Transcarpathian region using generalized results of hydrological, ichthyological and toxicological studies. Number of species status of populations, evaluated on the basis of documents, monitoring of rivers, ichthyological data during in 2008–2014 years of control catching specialists Department of the use, reproduction of water bio-resources and regulation of fisheries in the Transcarpathian region, the State Administration of Environmental Protection in Zakarpattya region, published and unpublished sources, a survey of local fishermen. Collection and processing of materials performed by conventional methods. Comparison of species composition of fish fauna of the Tysa River Basin within Zakarpattia region on the results of previous studies and the current state of evidence that it has changed significantly. Analysis of data for 1926–2015 years revealed the presence of 77 species, which is 41.5 percent more than the same period in 1926. However, should point to the increase in the number and activities of various threats to salmon and other valuable fish species in our region. Established prolonged human pressure, pollution reduced the number of new European grayling and Trout v 13.4 times. There were 16 species, including salmon, listed in the Red Book of Ukraine. Ceased to meet sturgeon passage. Study threats operation populations of salmon and endangered species gives reason to believe that the level of destruction of natural resources, environmental pollution, depletion of the gene pool is too narrow to study hydro. For the first time a comprehensive assessment of threats to salmon, valuable and endangered local fish Transcarpathia in terms of various specific human impact of their pressure from environmental factors in the past and now. A study of the action of environmental factors and implementation of scientifically based measures to restore fish in close to natural. The results can be used in developing preservation methods, quantitative growth of populations of salmon and endangered species not only in Zakarpattya but also in the Carpathian region, water protection planning activities.
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