Dams and other barriers block the migration of wild salmon, affecting both population viability and individual welfare through exhaustion, injury, and reproductive failure.
Wild salmon welfare is inseparable from habitat quality and migration access. Salmon are anadromous fish that spend part of their lives in freshwater and part at sea, and the completion of their spawning migration is essential to reproductive success. Barriers that prevent or impede this migration cause both population-level harm and individual welfare costs — fish exhaust themselves attempting to pass obstacles, sustain injuries, and may die without spawning. Dam removal and improved fish passage design are the most effective conservation and welfare interventions available. The welfare dimension adds individual moral weight to what might otherwise be framed purely as a conservation issue, broadening the ethical case for river restoration and barrier removal.