The efficiency of artificially reproducing Starlet (Acipenser ruthenus) and Common Carp (Cyprinus carpio) in upper Volga reservoirs

This study is dedicated to evaluating the effectiveness of artificial reproduction of sterlet ( Acipenser ruthenus ) and common carp ( Cyprinus carpio ) in the Upper Volga reservoirs: Ivan’kovskoye and Uglichskoye. Based on long-term data (2012–2024), an analysis of the dynamics of juvenile release, survival rates, and the formation of commercial stocks was conducted. The results revealed low effectiveness of the measures: despite substantial stocking volumes (up to 858 thousand sterlet and 703 thousand common carp specimens annually), individuals in catches were encountered sporadically. The projected commercial stocks by 2031 are estimated at 85.99 t for sterlet and 407.07 t for common carp; however, based on the results of previous releases, the actual stocks are forecast to be significantly lower. Key issues identified include: the lack of an economic analysis on the cost-effectiveness of releasing juveniles of different size/weight classes, low values of the exploitation rate/recapture rate, and a deficiency in long-term monitoring. It is proposed that specialized studies be conducted to develop science-based measures for enhancing the effectiveness of artificial reproduction activities.