The European eel has declined by over 95% since the 1970s, facing threats across its entire life cycle from glass eel stage to spawning migration in the Sargasso Sea.
Eel welfare is shaped by accumulating threats across a life that spans decades and an ocean. Individual eels carry parasite burdens that reduce their swimming capacity, then face physical barriers during migration, then survive turbine strike to complete a 5,000 km journey to a spawning ground where they die. The welfare of individual eels - including the capacity for pain and stress that evidence increasingly supports in fish - interacts with their catastrophic population decline. Removing river barriers, controlling illegal glass eel trade, and reducing turbine mortality are simultaneously conservation and welfare interventions.