Migratory fish species including salmon, eels, and sturgeon face welfare challenges from dams, fishways, and habitat degradation along their migration routes.
Migratory fish welfare is invisible to most people because it occurs in rivers, lakes, and at sea where human observation is limited. Salmon attempting to ascend fish passes expend far more energy than natural migration — weakening animals before they reach spawning grounds. The physiological transformation of spawning salmon — organ deterioration, immune suppression — is natural but dam-induced obstacles make it more severe. Dam removal is the single most effective welfare and conservation intervention for migratory fish.