Pacific Bluefin Tuna

About the Species

Although Pacific-wide populations are well below target levels, U.S. wild-caught Pacific bluefin tuna is a smart seafood choice because it is sustainably managed under rebuilding measures that limit harvest by U.S. fishermen.

Status

• According to the 2018 stock assessment, Pacific bluefin tuna are overfished and subject to overfishing.
• NOAA Fisheries first determined the Pacific bluefin tuna stock to be overfished in 2013. The 2018 assessment completed by the International Scientific Committee for Tuna and Tuna-Like Species in the North Pacific Ocean found the stock is still overfished.
• That assessment estimated that in 2016 the spawning stock biomass was at 3.3 percent of the level it would be had the stock never been fished. That’s up from 3 percent in 2014.

Appearance

• Pacific bluefin tuna have black or dark blue dorsal sides, with a grayish-green iridescence.
• Their bellies are dotted with silver or gray spots or bands.
• They have a series of small yellow fins, edged in black, running from the second dorsal fin to the tail.
• A distinguishing characteristic of Pacific bluefin is that the tips of the pectoral fins do not reach the front of the second dorsal fin.
• They have relatively small eyes compared to other species of tuna.

Biology

• Pacific bluefin tunas reach maturity at approximately 5 years of age and can live up to 26 years, although the average lifespan is about 15 years.
• Adults are approximately 1.5 meters (4 feet 11 inches) long and weigh about 60 kilograms (130 pounds).
• The maximum reported length and weight for Pacific bluefin is 3 meters (9.8 feet) in length and 450 kilograms (990 pounds).
• Pacific bluefin tunas are predatory and mainly eat squids and fishes, such as sardines and anchovies, saury, herring, pompanos, mackerel, hake, other tunas, and occasionally red crabs and krill. 

Where They Live

• Most of the U.S. catch of Pacific bluefin tuna is within about 100 nautical miles of the California coast. 

Management

• Management of highly migratory species, such as Pacific bluefin tuna, is complicated because they migrate thousands of miles across oceans and international borders and are fished by many nations.
• Effective conservation and management of these resources requires international cooperation as well as strong domestic management. The U.S. continues to encourage reductions in harvest to end international overfishing and begin a long-term rebuilding of the population.
• Two international organizations, the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCPFC), manage this fishery internationally. Working with the U.S. Department of State, NOAA Fisheries domestically implements the IATTC and WCPFC conservation and management measures.
• NOAA Fisheries, the Pacific Fishery Management Council, and the Western Pacific Fishery Management Council manage this fishery on the West Coast and in the Pacific Islands.
• Managed under the Fishery Management Plan for U.S. West Coast Fisheries for Highly Migratory Species and the Fishery Ecosystem Plan for the Pelagic Fisheries of the Western Pacific:
  • NOAA Fisheries works with the councils to provide recommendations to the Commissions and implement domestic regulations under the authority of the Magnuson-Stevens Fishery Conservation and Management Act (MSA).
  • The councils provide advice to NOAA Fisheries and the Department of State, so that the councils’ interests are represented in international negotiations.
  • Councils will also develop recommendations for domestic regulations to address the relative impact on the stock by U.S. vessels.
• Under the South Pacific Tuna Treaty, U.S. purse seine vessels operating throughout the western and central Pacific Ocean must be registered and are monitored through logbooks, cannery landing receipts, national surveillance activities, observers, and port sampling.
• Purse seiners in the Eastern Pacific also operate under the International Dolphin Conservation Program, a multilateral agreement aimed at reducing and minimizing bycatch of dolphins and undersize tuna.
• In 2000, the United States established the Dolphin-Safe Tuna Tracking and Verification Program to monitor the domestic production and importation of all frozen and processed tuna products nationwide, and to authenticate any associated dolphin-safe claim.