The restoration of spawning habitat for wild Atlantic and Pacific salmon is critical not only for conservation but for the welfare of individual fish that fail to complete their life cycle in degraded rivers.
Wild salmon undertaking spawning migrations that are blocked or frustrated by man-made barriers experience significant physiological stress. Fish that expend energy seeking passage that does not exist face exhaustion and increased vulnerability to predation and disease. Degraded spawning habitat results in high egg mortality. Welfare-sensitive river management includes maintaining fish passage at all barriers, controlling fine sediment inputs, and restoring riparian vegetation to regulate water temperature.