ABSTRACT
According to the results of field experiments with Chinook salmon spawners of various origins, i.e., those resulting from natural spawning (wild) and those resulting from artificial reproduction (hatchery), under conditions of joint spawning, a description of their spawning behavior and relative success in spawning is given. It is established that, at extremely high temperatures and low water levels in the region of investigation, as well as during the earlier introduction of hatchery fish to the spawning grounds, the hatchery females and the wild males had certain advantages in competing for spawning places and spawning mates. It is inferred from these observations, that, under optimum hydrological conditions and with the simultaneous introduction of fish of different origins to the spawning grounds, the wild spawners are more successful in spawning.