Document
2020 Highly Migratory Species Annual Report
This report focuses on work of SWFSC scientists on highly migratory fish species (HMS) and their…
Pacific Bluefin Tuna
Pacific Bluefin Tuna
Thunnus orientalis
Also Known As
Northern bluefin tuna, Tuna, Bluefin tuna
Quick Facts
Region
Pacific Islands,
West Coast
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.
Population
Significantly below target population levels. Rebuilding measures are in place for U.S. fishermen.
Fishing Rate
Reduced to end overfishing.
Habitat Impacts
Fishing gear used to catch bluefin tuna rarely contacts the seafloor so habitat impacts are minimal.
Bycatch
Regulations are in place to minimize bycatch.
Population Status
- According to the 2020 stock assessment, Pacific bluefin tuna are overfished and subject to overfishing. Summary stock assessment information can be found on Stock SMART.
- NOAA Fisheries first determined the Pacific bluefin tuna stock to be overfished in 2013. The 2020 assessment completed by the International Scientific Committee for Tuna and Tuna-Like Species in the North Pacific Ocean found the stock is still overfished.
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 tuna 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 tuna is 3 meters (9.8 feet) in length and 450 kilograms (990 pounds).
- Pacific bluefin tunas are predatory and mainly eat squids and fish, 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.
Fishery 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 United States continues to encourage harvest levels internationally that end overfishing and rebuild the population.
- Two international organizations, the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCPFC) coordinate management of this fishery across jurisdictions of member and cooperating nations. Working with the U.S. Department of State, NOAA Fisheries implements the IATTC and WCPFC conservation and management measures as regulations for U.S. fleets.
- NOAA Fisheries and the Pacific Fishery Management Council and the Western Pacific Fishery Management Council manage this fishery on the West Coast and in the Pacific Islands 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, respectively.
- 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.
Harvest
- Commercial fishery:
- The average annual bluefin landings by U.S. commercial vessels fishing in the eastern Pacific Ocean represent only 2 percent of the average annual landings from all fleets fishing there.
- U.S.-caught Pacific bluefin tuna are commonly landed in California by fishermen who sell to local restaurants.
- In 2019, U.S. commercial landings of Pacific bluefin tuna totaled approximately 603,000 pounds and were valued at more than $730,000, according to the NOAA Fisheries commercial fishing landings database.
- Gear types, habitat impacts, and bycatch:
- Purse seine, hook-and-line, and harpoon gear are used to catch Pacific bluefin tuna.
- Fishing gear used to catch bluefin tuna rarely contacts the seafloor so habitat impacts are minimal.
- These fishing methods are fairly selective and allow for the live release of unintentionally caught species.
- Recreational fishery:
- Pacific bluefin tuna are a highly valued species by recreational anglers.
- West Coast recreational fishing grounds primarily include offshore waters of southern California and northern Baja, and have historically included waters as far north as Monterey Bay.
- Commercial passenger fishing vessels and private boaters target Pacific bluefin tuna with recreational fishing gear using live bait (sardines or anchovy), casting jigs, and trolling jigs.
Featured News
Grilled tuna lemon with mayo. Credit: North Carolina Sea Grant/Vanda Lewis.