(Milan’s explanation that “Tuna” in NZ means fresh water eel.)
I am referring to fresh water eels. These particular eels are some 80 klm up river from the coast. As young elvers (baby eels) they traverse two water falls on their journey to get to the Hikurangi Swamp. They mature here for some 30 to 80 years old, then go on their migratory down river and out to sea for some 4,500 klm to the Tongan Trenches. They then return in the currents as larve type leaf, and form into elvers and head back up river to their chosen place to mature in our rivers and streams. They are not the same as salmon where they return to their place of birth. Elvers go wherever the current takes them. Maori (native peoples of NZ) refer to them as tuna, but yes to the European, they are fresh water eels ie. New Zealand Longfin eel (Anguilla dieffenbachii) and Shortfin (Anguilla australis)
They are prized here in NZ as kai (food delicacy) and are exported to Japan and Holland and much of Europe.