European eels are critically endangered while being farmed in large numbers, with poorly understood welfare needs and complex life histories.
Eel welfare is complicated by their unusual biology and significant knowledge gaps. Stress during wild capture and transport causes high mortality. Farmed eels are held at extremely high densities and fed artificial diets. Scientific understanding of eel consciousness and pain processing is limited but growing evidence suggests significant capacity for stress responses. The collapse of wild populations means aquaculture pressure will only increase.