Wild salmon undertake extraordinary migrations but face multiple welfare challenges from dams blocking their passage, warming rivers, and fishing methods that cause injury and stress.
Wild salmon in rivers face multiple welfare threats during their upstream migration. Fish ladders at many dams are ineffective or absent, blocking migration and causing exhaustion in fish attempting to jump barriers. Warming rivers cause heat stress and thermal barriers. Predation at fish ladders concentrates predators. Catch-and-release angling in spawning rivers causes exhaustion, oxygen debt, and increased predation risk if not properly handled. Commercial gillnet fishing causes drowning in fish trapped in nets. Pacific salmon in terminal stages of spawning show physiological deterioration that may involve significant pain and suffering as their bodies break down. River restoration through dam removal and habitat improvement represents one of the most impactful salmon welfare and conservation interventions available.