Longfin eels can be found throughout New Zealand, they live mainly in rivers and inland lakes but can be found in almost all types of waters, usually well inland from the coast.
Eels are strong climbers and make their way inland through most river systems. Elvers (young eels) swimming up river will climb waterfalls and even dams by leaving the water and wriggling over damp areas. It is not unheard of for an eel to climb a waterfall of up to 20 metres.
Fishing has had a significant impact on the species. Habitat loss is also a concern for these genteel creatures; changes cause by hydro development, drainage and irrigation schemes and river diversions affect eels by reducing their habitat and the water available for aquatic life. Eel habitat is also impacted by pollution. Sewage and effluent from meat works and pulp and paper plants can remove large quantities of oxygen from the water. The result of this oxygen depletion is that the fish will either die or move away.