Population Structure of Lenok (Brachymystax savinovi) in Lake Markakol and Preliminary Strategies for Species Conservation and Population Recovery

The Markakol lenok, Brachymystax savinovi, is an endemic salmonid inhabiting Lake Markakol and its tributaries in eastern Kazakhstan. Over the past century, both abundance and population structure of this taxon have been influenced by natural and anthropogenic factors, highlighting the need for updated assessments of its conservation status. This study evaluated the current population condition, habitat characteristics, and conservation prospects during 2020–2024. Results indicated that Lake Markakol maintained favourable hydrochemical and hydrological conditions during 2020–2024, with no evidence of substantial ecological degradation. The Markakol lenok population was characterised by the predominance of intermediate age classes, positive allometric growth, satisfactory condition factors, and a substantial proportion of mature individuals, indicating relatively stable population status and preserved reproductive potential. In addition, broodstock and replacement populations established under aquaculture conditions showed high survival and successful adaptation to different rearing technologies, confirming the feasibility of artificial propagation programmes for the conservation and sustainable management of the species. Wild brood fish from the Uidene River were successfully adapted to captive conditions, enabling establishment of broodstock and production of viable offspring under controlled conditions. These findings provide a scientific basis for conservation and restoration measures.