Yellowfin tuna is considered a single population in the western and central Pacific Ocean (WCPO) for stock assessment purposes (Vincent et al. 2020 and references cited therein), although there is still uncertainty about the stock structure along the Pacific Ocean.

The Parties to the Nauru Agreement (PNA) is an Oceania subregional agreement between the Federated States of Micronesia, Kiribati, Nauru, Palau, Papua New Guinea, Solomon Islands, Tuvatu, and the Marshall Islands. The PNA coordinates the implementation of management measures with a view to enhancing economic benefits from the fishery. Member countries of the PNA have adopted and implemented distinct Vessel Day Schemes for the longline and purse seine fisheries, whereby they allocate fishing days to a country which are sold to the highest bidder. The PNA unassociated (free school) fishery was MSC certified in 2011. All the PNA parties are Members of the WCPFC.

The Eastern Tuna and Billfish fishery targets yellowfin tuna, albacore, bigeye tuna, striped marlin and swordfish.

The primary gear used in this fishery is pelagic longlines (44 vessels), with handline, troll and rod and reel considered minor gears (7 vessels).

There is uncertainty as to the connectivity of yellowfin tuna in the ETBF to the broader western and central Pacific stock and it has been suggested it should be managed as a “relatively separate stock” (AFMA, 2012d). The map represents the distribution of the currently assumed single Western and Central Pacific stock.