Commercial-biological characteristics of bream (Abramis brama L.) in Volgograd reservoir

Biological indicators of bream (Abramis brama L.) – one of the most numerous species and the main object of fishing in the Volgograd reservoir have been studied. Data on the size-age composition and qualitative characteristics of bream in terms of fishing gear in different zones (areas) of the reservoir have been analyzed. According to the research of 2014–2018 the bream population is in a stable state. The catches are dominated by four to eight year olds. In the 1990s, the age structure was unstable and was characterized by a sawtooth population curve. According to earlier data from 1970–1998, the dominant age group was four to eight years old. Indicators of size and age characteristics are close to the average long-term values. The average age of the spawning part of the population is 6.3 years. Conditions for spawning and feeding grounds for juveniles in 2018 were unfavorable. From 2016 to the present, changes in the fishery after its reorganization can be observed. Restructuring consists in the distribution of fishing areas throughout the water area of the Volgograd reservoir. The growth of commercial catch from 371 to 472 t indicates a positive effect of the reorganization of the fishery. Analysis of the data showed that over the years, the age composition of the bream changed from an unstable state to a stable one. This is evidenced by the fact that the dominant age group has remained unchanged. The study of the impact of fishing on the abundance of bream in the Volgograd reservoir in the zonal aspect shows the maximum load on the population. According to the dynamics of the qualitative characteristics of bream caught by various fishing gear, fishing intensification is the limit.

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