The dynamics of commercial catches, stocks and forecast values of walleye catch on the Dagestan coast of the Caspian Sea with the analysis of factors affecting the state of stocks for a long-term period is presented. Data on seasonal distribution, migration, reproduction, as well as age and size-weight composition of walleye populations in the study area are presented. The forecast of prospects for the use of walleye by fishing is given on the basis of the analysis of commercial stocks for a number of years of observations, taking into account the coefficient of total mortality, the influence of fishing load, the values of the commercial population replenishment with first-matured fish.

Aim. Estimation of the natural reproduction efficiency and patterns of formation of fish stocks.Material and Methods. Collection of material was carried out in 2010-2019 in inland water bodies in Dagestan and its shallow Caspian Sea coastal zone. Estimation of the number of juveniles in rivers and canals was carried out using ichthyoplankton cone seines. Fry seines were used to count juveniles of fish in water bodies and in the coastal area. 470 samples of juveniles were collected and 5640 juveniles were analysed. The collection and processing of materials were carried out according to generally accepted methods.Results. The main environmental factors determining the productivity of fish juveniles in the study area in the long-term have been identified. During the observation period, juvenile fish of 15 species were recorded in spawning grounds of inland water bodies. Roach, bream, carp, crucian carp, rudd and vimba bream dominate. In terms of numbers, roach juveniles predominate: their relative proportion being 31.02% with an increase from 27.1% in 2010 to 35.4% in 2018.The second place was occupied by bream juveniles, whose average relative proportion was 12.1%. The third place was occupied by carp juveniles with an average proportion of 9%. Juvenile zander, catfish, pike and kutum are relatively low in abundance from 2 to 4%. The yield of juvenile fish in 2010-2019 decreased 1.7 times compared to 1990-1995.Conclusion. It was established that a decrease in the number of juvenile fishes occurs under the influence of unfavorable environmental factors: decrease in sea level; reduction in spawning areas; the shallowing and silting of migration routes due to the lack of a stable water supply. Measures are proposed to improve the living conditions of aquatic biological resources, aimed at increasing the efficiency of their natural reproduction.

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The article is devoted to the study of the commercial and biological characteristics of the wild goldfish in the coastal sea waters of the Terek-Caspian fisheries subdistrict. The features of the formation of wild goldfish stocks under the influence of natural-climatic and anthropogenic factors in the long-term aspect are shown. It has been revealed that in recent years, the stocks of wild goldfish in the coastal part of the Terek-Caspian fisheries subdistrict are stable and range from 1,210 to 1,950 thousand tons having reached the maximum in 2020. Biological indicators of wild goldfish in the coastal part of the Caspian Sea have been stable in recent years and are not subject to significant fluctuations. The high rate of increase in number and commercial stocks, as well as the expansion of the range of wild goldfish in new areas of habitat in the Caspian basin, is probably due to its competitive advantages - the ability to adapt to adverse environmental conditions.