Marine & Aquatic

Wild Salmon Migration Barriers: Fish Passage and Welfare

Dams, weirs and culverts block Atlantic salmon migration, causing exhaustion and death. Fish passage infrastructure and barrier removal are critical welfare interventions.

Key Facts

Atlantic salmon must migrate hundreds of kilometres between freshwater and sea
Physical barriers cause exhaustion, injury and death during migration attempts
Fish ladders and passes vary enormously in their effectiveness for salmon
Culverts designed for water flow often prevent upstream fish passage
River restoration removing barriers has dramatic salmon population recovery effects
Climate change increases river temperatures making migration physically more demanding

Welfare Considerations

Migration barriers cause salmon significant suffering through exhaustion from repeated failed passage attempts, injury from turbine strikes and delayed spawning that reduces reproductive success. The cumulative welfare cost across millions of individual fish is substantial. Effective fish passage infrastructure and priority removal of the most impactful barriers represent high-value investments in both welfare and conservation.

What You Can Do

Support river restoration projects removing obsolete dams and weirs
Advocate for effective fish passage assessment before any new water infrastructure
Donate to organisations working on salmon habitat and passage restoration
Encourage local water authority engagement on fish passage improvement