The European eel is critically endangered and faces welfare threats from barriers to migration, pollution, and parasites throughout its complex lifecycle.
Eel welfare is affected by the welfare costs of migration barriers, injury from turbines, and parasite burden throughout their lengthy lives. Eels passing through hydroelectric turbines suffer blade strikes, pressure changes, and shear stress that cause significant physical injuries including internal bleeding and spinal trauma. Even eels that physically survive turbine passage may sustain injuries that impair their breeding migration. River barriers that cannot be bypassed cause behavioral frustration in migration-motivated eels. The cumulative welfare costs of multiple barriers and hazards across a migration route represent significant individual suffering alongside population-level conservation impact.