Fish Passage and Dam Removal for Welfare

How removing obsolete dams and improving fish passage restores natural migration routes and dramatically improves welfare and population outcomes for migratory fish.

Key Facts

There are estimated to be over 1 million obsolete or abandoned dams in Europe alone blocking fish migration
Dam removal has produced dramatic fish population recovery in numerous case studies across Europe and North America
The Elwha River dam removals in Washington State produced one of the most studied fish population recoveries on record
Modern fish passage structures including nature-like bypasses are significantly more effective than traditional ladders
Dam removal is often cheaper than expensive dam rehabilitation and produces greater ecological and welfare benefits

Welfare Considerations

Dam removal is one of the most impactful welfare and conservation interventions available for migratory fish. Individual fish blocked from migration routes experience massive energy expenditure attempting to pass, spawning failure, and death. Population-level welfare harms compound over time as migration barriers reduce population sizes and genetic diversity. Dam removal produces rapid, documented welfare and population recovery because it restores the evolved migration ecology rather than providing partial mitigation. The case for prioritising dam removal over expensive fish ladder construction is increasingly supported by evidence comparing the effectiveness of both approaches.

What You Can Do

Support dam removal campaigns in rivers where migratory fish would benefit from restored access
Advocate for obsolete and unsafe dam removal programs funded by government infrastructure budgets
Donate to river restoration organisations working on dam removal and fish passage improvement projects
Learn about fish passage science and engage with river management decisions in your watershed
Engage with hydropower licensing bodies about mandatory fish passage effectiveness standards