Fish Passage and Migration Welfare

Dams and weirs that block fish migration routes cause mortality, energy depletion, and reproductive failure in migratory fish species, with welfare implications for billions of individual fish annually.

Key Facts

Over 60% of the world major river systems are fragmented by dams and other barriers
Migratory salmon attempting to pass impassable dams experience exhaustion and death below barriers
Fish ladders have variable effectiveness — poorly designed ones cause energy depletion without success
Dam removal is the most effective fish passage solution and has dramatic population recovery effects
Even partial passage improvements reduce energy cost and injury for migrating fish substantially

Welfare Considerations

Fish attempting to pass impassable barriers experience repeated exhaustion as they search for an upstream route that does not exist. The hormonal state of migratory fish — driven by breeding imperative — means they continue attempting passage until they die. Fish that successfully navigate poorly designed fish ladders expend enormous energy, arriving at upstream habitats depleted. Dam removal projects in the US and Europe have produced rapid, dramatic fish population recoveries, demonstrating the welfare and ecological benefit of reconnection.

What You Can Do

Support dam removal campaigns in rivers with migratory fish populations
Advocate for funding of effective fish passage improvements on existing dams
Donate to river restoration organizations working on fish connectivity
Raise awareness about dam fragmentation as a welfare issue for migratory fish
Engage with water management authorities about fish passage standards