BIOLOGICAL INDICATORS OF STERLET (ACIPENSER RUTHENUS, LINNAEUS, 1758) IN THE IRTYSH RIVER

Abstract

The article examines the habitat and biological characteristics of sterlet (Acipenser ruthenus) inhabiting the Irtysh River in the Pavlodar and Abay regions. Data on population length, weight, and age structure revealing differences between regions are presented. An analysis of ecological conditions, including the impact of hydropower plants, water pollution, and changes in hydrological regimes, was conducted. Particular attention was paid to the influence of anthropogenic factors, such as dam construction and poaching, on population numbers and distribution. The research results demonstrate that sterlet in the Pavlodar region achieves maximum length, while in the Abay region, it reaches maximum weight. It was also revealed that the rate of weight growth significantly exceeds the rate of length growth at later stages of development. The obtained data allow for predicting changes in population numbers and developing recommendations for their restoration. The article emphasizes the importance of conserving rare fish species and suggests measures to stabilize their populations, including the creation of specialized breeding programs, monitoring of spawning grounds, and control of anthropogenic impact. This research is crucial for the sustainable management of Kazakhstan's aquatic bioresources and ensuring their preservation for future generations.