On the issue of preserving sturgeon fish populations in the boundary waters of the Amur River in the 21st century.

The aim: to assess the current state of sturgeon fish populations in the Russian part of the boundary waters of the Amur River. Methods: the work is based on the results of expeditionary work carried out in 2007, 2008, 2010, 2011, 2013, 2018-2025 by employees of the Khabarovsk branch of the Federal State Budgetary Scientific Institution «VNIRO» in the Russian-­ Chinese border waters of the Amur River. The work was carried out in the mode of scientific surveys and at stationary points. Bottom drift nets and a beam trawl were used as fishing gear. Novelty: this publication summarizes previously unpublished data on the state of sturgeon fish populations in the Russian part of the boundary waters of the Amur River. Results: Based on the results of almost twenty years of research, it was established that in the boundary waters of the middle and upper reaches of the river the Amur sturgeon populations are in an unsatisfactory condition. A multiple decrease in the number of Kaluga and Amur sturgeon and a deterioration in the qualitative structure of the populations have been noted. We assume that the main factor that negatively affected the state of the stocks of both sturgeon species here was their large-­ scale industrial catch in the waters of the PRC. The artificial reproduction of Kaluga and Amur sturgeon in China, which has been deployed over the past 20 years, has not led to an increase in their numbers in the middle and upper reaches of the Amur. To restore sturgeons in the border waters of the Amur, comprehensive joint measures by the Russian Federation and the PRC are needed, consisting of maintaining aggregate reproduction by creating the most favorable conditions for the natural reproduction of sturgeon fish and their artificial reproduction with the release of large-­ sized juveniles. Practical significance: the obtained data will be used in the work of the joint Russian-­ Chinese commission in the field of fisheries to develop unified approaches to preserving sturgeon stocks in the border waters of the Amur River.