There are two stocks of albacore tuna (Thunnus alalunga) in the Pacific Ocean, one in the Northern hemisphere and the other in the Southern hemisphere. The North Pacific stock consists of all albacore tuna present in all waters in the Pacific Ocean North of the equator to 55°N (IATTC 2019).

The discreteness of these stocks is supported by fishery data, with lower catch rates in equatorial regions (Suzuki et al. 1977), tagging data (indicating there are no South Pacific Ocean recoveries of fish tagged in the North Pacific Ocean (Ramon 1996), ecological data (albacore larvae are rare in samples from equatorial waters (Ueyanagi 1969), and genetic data, with genetic differentiation between North and South Pacific albacore (Takagi 2001, Vaux et al. 2021). Thus, North Pacific albacore is assumed to be a discrete, reproductively isolated stock, with no internal sub-group structure within the stock (ISC 2020).

North Pacific Albacore fishery management is shared by the Western and Central Pacific Fisheries Commission (WCPFC) - Northern Committee (NC), and the Inter-American Tropical Tuna Commission (IATTC).