Wild salmon depend on free-flowing rivers for their life cycle. Habitat degradation and dam barriers cause population declines and individual welfare costs.
Wild salmon face a welfare challenge that is inseparable from their habitat and ecological context. The physiological demands of upstream migration are already extreme; salmon do not feed during this period and draw entirely on body reserves. Additional stressors including dam passage, elevated water temperatures, and degraded spawning habitat impose welfare costs that translate to reduced survival and reproductive success. At the individual level, fish that exhaust energy reserves before reaching spawning grounds experience physiological distress and failure. Dam removal is perhaps the most impactful single action for restoring conditions in which wild salmon can complete their life cycles successfully.