Significance of commercial return coefficients in fisheries research

Purpose of the study : determination of the area of applicability of commercial return coefficients in fisheries research using the example of whitefish of the Ob basin. Research methods : The calculated values of the coefficients for the period 1970-2015, as well as materials on artificial reproduction for 1986-2011, were used for the analysis. The number of fish was calculated using the restored stock method. The coefficients were checked according to the following criteria: the survival rate of juveniles; the return of producers from the number of larvae; the number of descendants of a pair of producers reaching puberty. Results : The analysis of various indicators confirmed the validity of replacing the previously valid coefficients with new ones. The relationship of coefficients with survival and the level of reserve utilization is shown. It is noted that this relationship is contained in the equation of the coefficient. Various aspects of the application of coefficients are considered. Special attention is paid to the analysis of changes in the intensity of fishing and natural reproduction, as well as the determination of the volume of IUU fishing. An increase in the level of use of generation by fishing has been established with a decrease in its number. Practical significance : The previously unused possibilities of using coefficients to determine the effectiveness of artificial reproduction, determine the volume of IUU fishing, predict the yield of generations and regulate fishing are disclosed.