It would look to co-ordinate tuna (eel) policy, grow tuna numbers, relate to commercial fishers and monitor results.
Whanganui tuna expert Ben Potaka said he didn't want the eel-fishing industry to determine the fate of tuna.
"We as customary fishers are a Treaty partner. We are not some little NGO. We want to be above them and talk directly to the Crown."
He had earlier spoken about the state of the piharau (lamprey) fishery. Piharau used to be a key food for Whanganui iwi, in their season.
They are now a threatened species, with a disease called lamprey reddening syndrome (LRS).