Members of the Parties to the Nauru agreement are reaping large returns off fishing vessel licenses but the PNA says the windfall won't last forever.
The eight member countries of the PNA and Tokelau employ a vessel day scheme which charges foreign ships at least US$8,000 a day to fish in their waters.
High demand for the limited number of fishing days has sparked a bidding war between companies with some paying as much as US$16,000 per day.
The outgoing CEO of the PNA, Transform Aqorau, said the demand reveals the value that could be obtained from fisheries but it would not last forever.
"I think we're still climbing up because I'm seeing the demand for days continuing to grow. So the value for these days will increase, but I think there will come a time when they will peter off," he said.
Transform Aqorau said it would probably level off in the next two to three years and when that happens they would need to look at other options such as dealing directly with processing plants and brand holders.
Dr Aqorau also adds those who want to change the vessel day scheme should think carefully.
The PNA has been pressured in the past to change the scheme or lower the price.
But Dr Aqorau said people were ignoring how long it would take to put this into practice.
"You're essentially dealing with different governments and they don't work like companies or a single government where you can make a decision and things happen."
"There's a level of confidence that has to be built around these different systems, there's a level of comfort, there's a level of discipline and there's huge investment in time and commitment into building these systems," he said.
Transform Aqorau said people may not be entirely satisfied with what has been achieved.