Wild Migratory Fish Welfare: Salmon and Eel Passage through Dams

Dams block fish migration routes, preventing anadromous and catadromous species from completing life cycles essential to their biology and welfare. Fish passage infrastructure addresses this problem with variable success.

Key Facts

An estimated 60% of the world's large river systems are fragmented by dams
European eels (Anguilla anguilla) have declined over 95% largely due to migration barriers and overfishing
Atlantic salmon populations in many rivers are at 10% or less of historical levels
Fish ladders and bypass channels allow passage but have variable effectiveness by species
Dam removal is the most effective restoration measure — over 1,400 dams have been removed in the US since 2000

Welfare Considerations

Dam barriers cause welfare harm through two mechanisms: direct physical injury from turbines during downstream passage, and behavioral frustration of migratory motivation that may represent a form of suffering. Fish attempting to pass downstream turbines suffer injury rates of 5-30% per turbine encounter depending on design. Upstream migrants attempting to scale unpassable barriers exhibit persistent, energetically costly jumping behavior before abandoning attempts. Dam removal resolves both problems simultaneously, allowing natural migratory behavior and eliminating turbine mortality. Fish passage infrastructure is a partial solution — effectiveness varies by species, flow conditions, and design quality.

What You Can Do

Support dam removal advocacy in your region through river conservation organizations
Advocate for fish-friendly turbine design standards in hydropower licensing requirements
Donate to salmon and eel conservation organizations monitoring migration route restoration
Support sustainable fishing certifications that account for habitat and migration route integrity
Reduce electricity consumption to decrease demand for hydropower that may harm migratory fish