A new licensing system for longline fishing vessels in the Pacific will go into effect at the beginning of next year.
The Parties to the Nauru Agreement, or PNA, will no longer sell licenses for individual longline vessels, which use hooks and lines to catch tuna.
Instead, PNA is shifting the boats to a so-called vessel day scheme by selling a limited number of days to fishing companies that are based on size and sophistication of vessels.
Longliners target bigeye tuna, a lucrative catch for Asia's sashimi markets but one that scientists warn is being heavily overfished.
The eight PNA island nations control waters where the bulk of the Pacific's three-billion US dollar annual tuna haul is caught.
Until recently, they have focused on the purse seine industry, the fishing vessels that use a massive net to catch skipjack tuna for canning.