Current state of the European grayling (Thymallus thymallus L.) in Ukraine and conservation strategy for population support. A review

This paper attempts to review the methods and experiences in preserving and restoring grayling stocks in water bodies, which this species currently inhabits or previously inhabited. The study includes a retrospective analysis of the status of grayling populations in their natural conditions as well as a review of current ecological and anthropogenic factors negatively impacting the survival and reproduction of the European grayling in Carpathians. The review includes both foreign and Ukrainian experiences in the creation of broodstocks, which could be used to restore grayling populations in Ukrainian waters in the future. We discuss the use of molecular methods for controlling and maintaining the optimal state of European grayling broodstocks at fish hatcheries as well as their application in supporting river restocking efforts to restore ichthyosis is also discussed. We highlight the state and contemporary problems for the existence of the European grayling in Ukraine. The review presents fundamental approaches using aquaculture and molecular methods that can be employed to address ongoing tasks and challenges in grayling stock recovery.