BIOLOGICAL CHARACTERISTICS AND POPULATION DYNAMICS OF COMMERCIAL CATCHES CARP FISH (CYPRINOIDEI) IN THE CONTEXT OF MODERN ENVIRONMENTAL CHANGES IN THE SMALL ARAL SEA

Abstract

Since 2006, the restoration of the hydro-ecological conditions of the Small Aral Sea has increased the probability of survival for many fish species. The salinity of the water decreased to 10 ppm, leading to a gradual recovery of the food base. However, over the past decade, the hydrological situation in the sea has begun to deteriorate: the previously favorable water level of 42 mBS, covering an area of 330 thousand hectares, has decreased to 40.8 mBS, reducing the area to 285 thousand hectares.

Currently, carp fish (Cyprinoidei) dominate the ichthyofauna of the Small Aral Sea, with 12 out of the 22 recorded species belonging to this family. The distribution of carp species across the sea is uneven, as the water body is conditionally divided into three distinct biotopes: saline, feed-rich, and freshwater areas, each differing in chemical water composition and nutrient reserves.

In this study, biological parameters of carp fish species were analyzed using pond nets in various biotopes. The article examines the current state of carp fish species in the Small Aral Sea over recent years, focusing on their size-age structure and distribution across biotopes. Additionally, recommendations are provided for the further reproduction of carp species under favorable environmental conditions.