the Buller River (which flows from Lake Rotora) is the sure bet to look for particularly large Long Finned Eels , some remote areas of the River have been measured between 25-35 mtrs in depth with deeper fissure cracks along the riverbed. Here are where these Denizens lurk , waiting for their diet to drift by.
In the gold rush era within this district , many a Gold Miner lost their lives…(drowning with alcahol probable cause?) , never to be recovered and most likely consumed by the opportunistic Eel.
Further reference available