Salmon habitat restoration — removing dams, restoring riparian zones, improving water quality — directly improves welfare for millions of individual fish.
Habitat restoration is a high-leverage welfare intervention for wild fish because it improves conditions for entire populations rather than individuals. Salmon migrating through degraded rivers experience elevated water temperatures that cause physiological stress and increased disease susceptibility, physical exhaustion from passage around barriers, and reduced spawning success that affects the welfare calculation of the next generation. Dam removal enables fish to complete their life cycle without the extreme physiological cost of blocked migration. Water temperature reductions from riparian restoration reduce thermal stress during the most demanding periods of the salmon life cycle. These population-level welfare gains represent enormous cumulative benefit.