101Kuybyshev Reservoir, the largest reconstructed water body of the basin of the Volga and Europe, is characterized by a rather complex morphology and heterogeneity of conditions of different parts. This cir cumstance manifests itself not only under different hydrological conditions of individual areas but also in the specifics of the anthropogenic impact (Kuiby shevskoe vodokhranilishche, 2008). With respect to ichthyofauna, it was shown that heterogeneity becomes a cause of different contributions of isolated parts of the water body to reproduction of the fish stock (Kuznetsov, 1978;Kuznetsov and Galanin, 2000). The late 1980s were marked by an increase in fish invasions in the Volga and Don basins that assumed a pattern of mass explosive expansion espe cially for representatives of the family Gobiidae (Slyn'ko et al., 2010). One should expect that the rate of bioinvasion processes in some areas of the reservoir will be different. The purpose of the paper is, on the basis of long term observations, to generalize the fact of catches of gobies of the genera Neogobius and Prot erorhinus dwelling near the shore of the Volga stretch of the Kuybyshev Reservoir and compare them with available data on other areas of the reservoir. MATERIALS AND METHODSThe material for the work comprised data on regis tration of gobies in the course of annual observations of the state of juvenile fish near the shore, results of control catches with gill nets (mesh of 16-65 mm), and episodic evidence on catches of gobies with hook and line gear for the period of 1993-2009 in the upper part of the Volga stretch of the Kuybyshev Reservoir. Observations of the state of juvenile fish near the shore were performed in July and September using fry drag seine (length of 12 m, mesh in the wings of 5 mm, mesh in the seine bag of 2.5 mm) and gas drag seines (length of 3 m, gas no. 10) at 18 stations of the littoral at two sections: in the lower reaches of Sviyaga Bay and in the Volga Sviyaga area. Besides this, data on other areas of the Kuybyshev Reservoir were used in the paper. For analysis, similar materials obtained in the course of work in different areas of the Kama stretch in the period of 2006-2007 were also used. The numbers of fish were assessed in specimens per one fishing effort. RESULTS AND DISCUSSIONAt the present stage, near the shore of the upper part of the Volga stretch of the Kuybyshev Reservoir, there are two representatives of the genus Neogobius and one of the genus Proterorhinus. Data of observa tions for the period of 1993-1999 reflect a complete absence of gobies in the composition of catches of juveniles in the littoral and gill nets. Round goby Neogobius melanostomus (Pallas, 1814) was the first to be found in this area (Fig. 1). The first three young of the current year gobies were caught in 2000. Near the shore, round goby is common on rocky grounds and also occurs less frequently in other habitats. Since rocky grounds in the littoral of the considered areas are not widespread, the total numbers of this species in rec...

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The current state of size and weight parameters and age structure of silver bream in the upper part of the Volga stretch of the Kuibyshev water reservoir show persistence of a negative trend at the beginning of the current century: a decrease in the size and weight parameters of the silver bream and an increase in the number of younger fish. The current situation can be considered as an indicator of the general negative state of fish resources in the study area.

The article describes the state of the White bream in the upper reaches of the Kuibyshev reservoir in the period from 2009 to 2019.

In recent years, the silver bream of the upper part of the Volga stretch of the Kuibyshev reservoir maintained a tendency to reduce the average size and weight indicators. Given the good availability of food and the fact that in the area under consideration, commercial fishing of this species has not been carried out in recent years, it can be assumed that changes in biological indicators are caused by a significant impact of anthropogenic impact in the form of individual and poaching fishing. It is necessary to strengthen control measures for such types of fishing.