An assessment unit is considered to exist in the Indian Ocean by the Indian Ocean Tuna Commission (IOTC 2019).

In Indonesia, yellowfin tuna distribution areas cover the waters of west and south of Sumatra, southern Java, Bali and Nusa Tenggara, Banda Sea and Mallucas island’s sea, Sulawesi sea and western waters of Papua. Their nature as a highly migratory species resulted in the possibility of mixing fish populations, especially for the territorial waters of Indonesia that have the characteristics of archipelagic waters directly adjacent to the ocean waters. Genetic data information of yellowfin tuna obtained can be relied upon in resource management (Akbar and Aris 2018). There is no difference in the structure of yellowfin tuna populations in FMA 572 and FMA 573 (LP2T 2016). The population structure of madidihang in the western and eastern Indian Ocean regions shows no significant results of subpopulation differences (Chow et al. 2000) (Nishida and Tanaka 2004).