European Eel Migration Welfare and Conservation

European eels undertake one of the most extraordinary migrations in the animal kingdom, facing catastrophic population decline and multiple welfare threats.

Key Facts

European eels migrate from European rivers to the Sargasso Sea to spawn, a journey of 5,000+ km
The population has declined by 90-95% since the 1970s
Migration barriers including dams and weirs block 90% of eel habitat in some river systems
Parasitic swimbladder worm (Anguillicoloides crassus) introduced from Asia severely impairs migration capacity
Eels affected by the swimbladder worm cannot inflate their swim bladder properly, affecting their ability to migrate

Welfare Considerations

European eel welfare is affected throughout their complex life history. Juvenile eels blocked by dams experience physiological stress and inability to reach suitable habitat. Silver eels (migrating adults) infected with swimbladder parasites experience reduced swim bladder function and impaired migration, meaning many cannot complete the journey to spawning grounds. The catastrophic population decline means each individual eel's welfare and survival is a significant conservation as well as welfare concern. River restoration enabling migration and parasite reduction improve both individual welfare and population recovery simultaneously.

What You Can Do

Support river restoration and barrier removal enabling eel migration through river systems
Advocate for eel-specific passages at all river barriers in eel distribution range
Avoid consuming European eel until populations recover to sustainable levels
Support research into swimbladder parasite control as a welfare and conservation intervention