The food supply of the pacific salmon of the genus Oncorhynchus in the northwestern pacific ocean. 1. The dynamics of the food spectra and feeding intensity

Abstract

Based on the data of 28 surveys that were carried out by the Pacific Fisheries Research Center in the Sea of Okhotsk, Bering Sea, and Pacific waters during 2001-2010, we analyzed the interannual variability of indirect indices of the food supply of the Pacific salmon (Oncorhynchus): the daily food ration, daily con� sumption rate, diel feeding chronology, diet overlap, trophic niche breadth, number of prey items, and the share of minor food. The years of the most pronounced changes in the diet composition and consumption rate of Pacific salmon were revealed. The variability of different trophic characteristics as indicators of the salmon food supply is discussed. Despite a significant increase in salmon abundance in the 2000s compared to previous years, no marked changes occurred in their feeding spectra and consumption rates.