Seasonal Changes in Feeding of Coho and Chinook (Spring) Salmon in Southern British Columbia Waters

Food study based on the stomach analyses of 551 chinook salmon (Oncorhynchus tshawytscha) and 659 coho salmon (O. kisutch) collected from the various localities along the southern British Columbia coast during the summer of 1957 revealed that herring followed by crustaceans formed the most important items of the diet of the two species. Coho salmon exhibited a more pelagic and varied diet than chinook salmon caught in the same area. Definite seasonal fluctuations in the composition of food and feeding intensity were noticed. Considerable amounts of Crustacea were taken in early summer months and after that fish assumed importance.Qualitative and quantitative differences in the feeding of these two species on the east and west coasts of Vancouver Island appear to warrant the establishment of two food type areas, Although herring constitute the major food item of both spring and coho salmon, evidences are presented in support of the hypothesis that a change in herring stock is not likely to affect salmon abundance in British Columbia coastal waters.