Migratory fish face extreme welfare challenges from dams, pollution, and habitat alteration that block or compromise their spawning migrations. The welfare dimensions of these barriers deserve attention alongside conservation concerns.
The welfare of migratory fish is largely invisible because it occurs in rivers and oceans rather than in settings where humans directly observe animal suffering. Yet the barriers migratory fish face — dams, pollution, degraded water quality — cause significant individual suffering alongside population collapse. Fish attempting to ascend fish ladders experience exhaustion, disorientation, and increased predation exposure. Fish stranded below impassable barriers may attempt passage repeatedly in conditions of declining physical condition. Juvenile fish descending past hydroelectric turbines face injury and mortality. The welfare and conservation cases for dam removal and passage improvement are aligned: removing barriers that cause individual fish suffering also allows population recovery. Few interventions offer such convergent benefits.