European eel populations have declined by over 90 percent since the 1980s, creating a welfare crisis for individual eels across their complex lifecycle in addition to a conservation emergency.
European eel welfare at the individual level includes the stress and mortality from glass eel fisheries, blocked migration routes that prevent adults from reaching suitable habitat, and the physiological demands of an extraordinary lifecycle that spans decades and multiple ocean crossings. Eels blocked by barriers and unable to migrate to freshwater feeding grounds expend energy in repeated failed passage attempts. Adult silver eels making the 5,000-kilometre return migration to the Sargasso Sea face gauntlets of fishing nets, hydropower turbines, and predators that kill significant proportions of migrating individuals. River barrier removal and effective eel passes represent the most direct welfare and conservation interventions currently available.