There are five species of tuna that are the main focus of international fisheries:
1. Bigeye (Thunnus obesus)
2. Yellowfin (Thunnus albacares)
3. Atlantic and South Pacific Bluefin (Thunnus thynnus)
4. Skipjack (Euhynnus pelamis)
5. Albacore (Thunnus alalunga)
Each of these species differs in where they are predominately located, their basic biology and their market value. The biological status of tuna fisheries and the extent to which a particular tuna stock may be overfished varies geographically. Tunas are highly migratory; moving across ocean basins and between the high seas and waters under the national jurisdiction of many nations.
With the goal of ensuring the sustainable use and long-term conservation of tuna stocks, nations have come together to negotiate and establish international organizations through which countries that fish for tuna resources can agree to a common set of measures to manage and conserve those stocks throughout their range within a region. These organizations are commonly referred to as Regional Fishery Management Organizations or RFMOs. Currently, five RFMOs have been established that deal specifically with tuna fisheries:
The United States is a party to three of these: ICCAT, IATTC, and WCPFC.
The National Oceanic and Atmospheric Administration (NOAA) Fisheries Service has the lead in managing U.S. tuna fisheries in the Atlantic and Pacific Oceans; the State Department works closely with NOAA fisheries to negotiate international measures through these RFMOs.
The State Department also oversees a treaty between the United States and 16 Pacific Island nations. This treaty is commonly referred to as the South Pacific Tuna Treaty and has been in force since 1987.