When people think about the world’s most threatened animals, it’s unlikely that Anguillid (freshwater) eels spring to mind. In Europe, freshwater eels are one of our least appreciated but most critically endangered species, having declined by around 95% since the 1980s. Unlike most people, as a freshwater ecologist, I spend a lot of time thinking about animals like the freshwater eel because globally, all freshwater species are facing considerable threats.