About the fertility of pink salmon Iturup Island

Abstract

The purpose of the work is to present data for the last 15 years and analyze the fecundity of pink salmon at the present stage of its natural and hatchery reproduction on the island Iturup.The research material was based on the results of biological analysis of pink salmon breeders running to spawn in the basins of Prostor and Kurilsky bays (Iturup Island, Sakhalin region) in July-September 2008–2022. Methods used: standard methods of biological analysis, descriptive statistics methods.Results: it was established that over the past 15 years there has been a trend towards a decrease in the weight of female pink salmon. The value of absolute fecundity during this period varied from 289 to 3568 oocytes, and on average, with one exception, ranged from 1277 to 1640 oocytes. Fecundity was positively but weakly correlated with the length and weight of females within each of the annual samples, and the reliability of this relationship was achieved due to the volume of the samples. The relationship between the fecundity and weight was stronger than that between the fecundity and the length of fish. Average fecundity values were closely correlated with the average weight of females, and, therefore, as in the case of fish weight, in the period from 2008 to 2022 there was a trend toward a decrease in average fecundity values.Practical significance: we studied the fertility of female pink salmon from the only large commercial stock in Russia, formed through natural and hatchery reproduction.