Abstract— <p>The results of the study of annual variability in age composition, body size and growth rate of the Anadyr chum salmon <i>Oncorhynchus keta</i> in 2011–2023 revealed that the length and body weight of individuals of all age groups in 2016–2023 significantly decreased compared to the previous period, especially in fish aged 0.4. The proportion of fish of the younger age groups increased. Based on the calculated data, in 2012–2022, the growth rate of chum salmon decreased in the first to second years of life, and multidirectional trends were observed in the third to fourth years, with the lowest increase in the body length in 2016 and 2020. The decrease in the production characteristics of Anadyr chum salmon in the modern period occurred simultaneously with a decrease in the abundance of this salmon species throughout its entire marine range in the North Pacific and depended little on the abundance of other salmon species. The data obtained cast doubt on the leading role of the so-called density factor in determining the production characteristics of fish, which is expressed in food shortages due to an increase in the abundance of Pacific salmon. The abnormally high surface temperatures in the northeast Pacific Ocean over the past seven to eight years have had a marked negative impact on the growth of Anadyr chum salmon.</p>