Aquatic Animals

Wild Migratory Fish Passage Requirements

Fish passage standards at dams and barriers determine whether migratory fish can complete their life cycles.

Key Facts

Fish ladders allow passage for salmon but are less effective for lamprey and eels
Modern bypass channels better replicate natural flow conditions
Over 1 million barriers fragment European rivers, blocking fish migration
Barrier removal is increasingly preferred over fish passage construction

Welfare Considerations

Migratory fish unable to complete their spawning migrations experience a welfare failure when physiological readiness cannot be expressed behaviorally. Fish blocked at barriers may attempt migration repeatedly, exhausting themselves, with behavioral and presumably subjective costs.

What You Can Do

Support river barrier removal campaigns in your region
Advocate for fish passage requirements in hydropower licensing
Back research into most effective passage designs for different species
Donate to river restoration organizations working on migration barrier removal