According to the materials of 2019–2021, it is shown that there were no significant changes in the biological parameters of the individuals of the commercial stock of the least cisco in the Yana River of the Republic of Sakha (Yakutia) for three years. Some increase in the average values of fish length and weight in 2021 was due to a shift in their age structure towards an increase in the number of individuals of older age groups and alignment of the sex ratio. Analysis of the fishery status of the species for 2011–2021 showed two shifts in the dominant age groups of least cisco in the catches. In the first two years of the last decade, fishery was based on fish aged 4+ and 5+, then the main proportion in the fishery was made up of individuals aged 5+ and 6+. By the beginning of the current decade, the situation had returned to its original level. In general, the dynamics of the test cisco fishery in the Yana River is characterized by stability, the harvesting does not cause serious damage to the number of the species, the current state of stocks of which in the river is satisfactory. The results make it possible to predict an increase in the abundance of the studied population.
I.A. Petrov (Wed,) studied this question.