Yellowfin tuna (Thunnus albacares) is widely distributed in the tropical and subtropical waters of the Pacific Ocean and albeit it is considered a highly migratory species, the tagging studies done in the EPO region have indicated that yellowfin tuna move in restricted areas (Minte-Vera et al. 2020). While yellowfin tuna in the EPO may be composed of spatially disaggregated units there is no sufficient data to estimate movement rates or assist in delimitating these units (Minte-Vera et al. 2020). Here, it is assumed that there is a single stock of yellowfin tuna in the EPO.

Regular stock assessment is developed by the Inter-American Tropical Tuna Commission (IATTC), the same entity that sets conservation and management measures for this stock in this region.