Restoring degraded salmon rivers improves the welfare of wild fish populations by providing adequate spawning habitat, clean water, and passage to breeding grounds.
Salmon habitat restoration is welfare work at scale — improving river conditions directly reduces the physiological stress, foraging difficulty, and reproductive failure experienced by individual fish in degraded environments. Fish attempting to spawn in poor-quality gravel have lower reproductive success and expend more energy on an already-demanding process. Fish ascending rivers with inadequate flow or obstructed by impassable barriers experience stress and sometimes die without spawning. Cool, well-oxygenated rivers with appropriate structure support fish welfare throughout their freshwater life. The accumulated evidence from restoration projects demonstrates that habitat recovery translates to population recovery, meaning welfare improvements and conservation outcomes are aligned in this context.