Pacific Bluefin Tuna

Thunnus orientalis

ALSO KNOWN AS:

  • Northern bluefin tuna, Tuna, Bluefin tuna

SOURCE:

  • U.S. wild caught along the West Coast of North America
 

STATUS

  • POPULATION
  • FISHING RATE
  • HABITAT IMPACTS
  • BYCATCH
 

Click the icons to learn more about each criteria

 
 

OVERVIEW

School of bluefin tuna. Photo credit: NOAA Fisheries.

LAUNCH GALLERY

Three species of bluefin tuna are found around the world—Northern (or Atlantic) bluefin tuna (Thunnus thynnus), Southern bluefin tuna (Thunnus maccoyh) and Pacific bluefin tuna (Thunnus orientalis). Pacific bluefin tuna is managed as a single stock and is primarily found in the North Pacific Ocean, ranging from East Asia to the North American West Coast.

The Pacific bluefin tuna has a streamlined body and a high powered muscle system which makes it one of the fastest fish in the Pacific Ocean. Bluefin tunas are warm blooded, and unlike cold blooded fish, they can keep their body temperature higher than the surrounding water. This allows them to achieve great power and speeds, sometimes reaching sprint speeds of up to 60 miles per hour. Being warm blooded also means that their range is less limited by water temperatures and climate variability.

Commercial and recreational fisheries for Pacific bluefin tuna have existed for thousands of years. As sushi and sashimi markets developed in the 1970s and 1980s, the demand and prices for bluefin tuna soared.    

Today, tuna remain a commercially important species around the world. As fisheries expanded, fishing pressure increased dramatically, and many bluefin tuna populations are currently overfished. Since bluefin tuna are late to mature, slow-growing, and long lived, they are especially vulnerable to fishing pressure compared to faster growing, more productive species. Many nations harvest bluefin tuna and effective conservation and management of this resource and its fisheries requires strong international cooperation. In 2013, the Inter-American Tropical Tuna Commission (IATTC) developed conservation and management measures for bluefin tuna, including international catch limits. Other management organizations, like the Western Central Pacific Fisheries Commission (WCPFC) have also adopted conservation and management measures. U.S. fisheries generally harvest a small fraction of the total Pacific-wide bluefin harvest, and represent only two percent of the average annual landings from all fleets fishing in the Eastern Pacific Ocean.

Looking Ahead

In June 2013, the Inter-American Tropical Tuna Commission (IATTC) dislaimer met to consider the Pacific bluefin assessment and developed conservation and management measures dislaimer, including a commercial catch limit of 5,000 metric tons for 2014.

 

The Pacific Fishery Management Council met in June 2013 and in response to the overfished status of Pacific bluefin tuna, recommended that the U.S. government advocate for a higher level of protection for Pacific bluefin tuna in international fisheries. Read more in the June 2013 decision summary from the meeting.

 

In December 2013, the Western Central Pacific Fisheries Commission (WCPFC) dislaimer Northern Committee adopted a conservation and management measure specifying that total fishing effort by their vessels fishing for Pacific bluefin tuna in the area north of 20 degrees shall stay below the 2002-2004 annual average levels during 2014. Read more about the December 2013 decision dislaimer.

 
 
 

LOCATION & HABITAT

The Pacific bluefin tuna is primarily found in the North Pacific Ocean, ranging from East Asia (from Sakhalin Island in the southern Sea of Okhotsk south to the northern Philippines) to the North American West Coast (Gulf of Alaska to southern California and Baja California, Mexico). It is mainly an open water species found mostly in temperate ocean waters but also in the tropics and cooler coastal regions.

Larger adult bluefin rarely inhabit waters within the U.S. EEZ (exclusive economic zone), which stretches from 3-200 miles offshore. However, on occasion, catches of these larger fish occur in the vicinity of the Channel Islands off southern California and the central California coast.

Of the tunas, Pacific bluefin tuna have the largest geographic range. Tagging studies dislaimer, conducted with conventional and archival tags, have revealed a great deal of information about the life history of bluefin. While some bluefin spend their entire lives in the Western Pacific Ocean, others migrate to the Eastern Pacific Ocean, typically during their first and second years of life. Pacific bluefin spawn in the Western Pacific Ocean between central Japan and the northern Philippines from April through June. The larvae are carried by the Kuroshio Current north during the summer through winter of the first year. Fish ages 0-1 tend to migrate north along the Japanese and Korean coasts in the summer and migrate south in the winter. Some juvenile fish are carried east along the North Pacific Gyre and at 10-14 months arrive off the coast of southern Baja California. After 2-6 years in the Eastern Pacific, the bluefin return to the Western Pacific Ocean to spawn. Their trans-Pacific journey can take as few as 55 days.

 
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BIOLOGY

Pacific bluefin tunas reach maturity at approximately 5 years of age and can live up to 26 years, although the average lifespan of a bluefin is about 15 years. Adults are approximately 1.5 meters (4 feet 11 inches) long and weigh about 60 kilograms (130 pounds), but larger ones have been seen. 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, and other tunas. Occasionally they eat red crabs and krill.

 
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PHYSICAL DESCRIPTION

Pacific bluefin tuna have black or dark blue dorsal sides, with a greyish-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 also have relatively small eyes compared to other species of tuna.

 
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OVERVIEW

Because the stock occurs Pacific-wide, stock assessments are conducted by the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific Ocean (ISC) dislaimer. The ISC has formed working groups for Pacific bluefin tuna, North Pacific albacore, billfish (marlins and swordfish), and sharks. ISC annual Plenary Reports dislaimer provide stock status updates and conservation recommendations. NOAA Fisheries scientists from the Southwest Fisheries Science Center and the Pacific Islands Fisheries Science Center participate in the ISC assessments and contribute relevant U.S. fishery data. The Southwest Fisheries Science Center served as the NOAA Fisheries lead for the Pacific bluefin tuna assessment, which was completed in December 2014. NOAA Fisheries believes the 2014 stock assessment to be the best available scientific information for management purposes.

 
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POPULATION STATUS

The 2014 Pacific bluefin tuna stock assessment conducted by the ISC used data going back to 1952. The ISC concluded that the stock continues to be both overfished and subject to overfishing. In 2013 NOAA Fisheries listed the stock as overfished for the first time based on the 2012 assessment. The 2014 assessment estimated that the 2012 spawning stock biomass was at about 4 percent of the level it would be had the stock never been fished, and spawning stock biomass has been declining for more than a decade.

 
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Harvesting

Bluefin tuna are caught during every month of the year but mostly between May and October. In the United States, most bluefin tuna are caught using purse seines and hand gear (rod and reel, handline, harpoon) that target schools of tuna. These gear types are fairly selective. They rarely contact the ocean floor, have minimal impact on habitat, and allow for the live release of any unintentionally caught species.

Most of the U.S. catch is within about 100 nautical miles of the California coast. Ninety percent of the bluefin caught are between 60 and 100 centimeters in length, representing mostly fish one to three years of age.

The U.S. West Coast coastal purse seine fleet opportunistically targets bluefin tuna when they are available. Otherwise, the fleet primarily targets coastal pelagic species such as jack mackerel, market squid, northern anchovy, Pacific mackerel, and Pacific sardine. In 2004, NOAA Fisheries initiated a monitoring and a pilot observer program for the coastal purse seine fishery targeting coastal pelagic species off California.

Internationally, in the Western Pacific Ocean, and especially in the sea of Japan, fishermen catch bluefin tuna using traps, gillnets, and other gear. Small amounts of bluefin are caught by longline fishermen near the southeastern coast of Japan. The Chinese Taipei small-scale longline fishery, which has expanded since 1996, catches bluefin tuna more than 180 centimeters in length from late April to June, when they are aggregated for spawning in the waters east of the northern Philippines and Taiwan.

The high-seas purse seine and longline fisheries target mainly tropical tunas, albacore, and billfishes, but small amounts of Pacific bluefin are caught by these fisheries. Small amounts of bluefin are also caught by Japanese pole-and-line vessels on the high seas.

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Management

Who’s in charge? Management of highly migratory species, like the Pacific bluefin tuna, is complicated because the species migrate thousands of miles across international borders and are fished by many nations. Effective conservation and management of this resource requires international cooperation as well as strong domestic management.

Current management:

International: The U.S. is party to two international Regional Fishery Management Organizations in the Pacific: the Inter-American Tropical Tuna Commission (IATTC) dislaimer and the Western and Central Pacific Fisheries Commission (WCPFC) dislaimer. These Commissions rely on the scientific advice of their staff and the analyses of the International Scientific Committee for Tuna and Tuna like Species in the North Pacific (ISC) dislaimer to develop and adopt international resolutions for conservation and management measures. Working with the Department of State, NOAA Fisheries domestically implements these conservation and management measures under the authority of the Tuna Conventions Act.

The IATTC and the WCPFC adopted and the United States implemented conservation and management measures to address overfishing of Pacific bluefin. In 2013, IATTC adopted a catch limit of 5,000 metric tons for 2014 for Pacific bluefin harvested from the entire Eastern Pacific Ocean. Also in 2012, the WCPFC adopted effort controls on bluefin fishing in the western central Pacific Ocean to ensure that the current level of fishing mortality does not increase.

Domestic: West Coast: Highly migratory species fisheries management plans for the Pacific and Western Pacific Fishery Management Councils.

  • NOAA Fisheries works with the councils to provide recommendations to the Commissions and to 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 council’s interests are represented in international negotiations. Some of their current recommendations are to:
    • Increase public awareness about West Coast highly migratory species issues.
    • Facilitate greater public involvement in managing highly migratory species fisheries.
    • Garner congressional support for the study and management of highly migratory species.

Under the MSA, when overfishing is occurring (fishing mortality is above the maximum fishing mortality threshold) or the stock is overfished (biomass is less than the minimum stock size threshold), the councils will develop recommendations to the Secretary of State and Congress for international actions to end overfishing and rebuild the stock, taking into account the relative impact of vessels of other nations and the U.S. on the stock. In addition, the councils will develop recommendations for domestic regulations to address the relative impact on the stock by U.S. vessels. Both actions need to be completed within one year of the Secretary’s determination that overfishing is occurring.

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Annual Harvest

Catch data for Pacific bluefin tuna in the entire Pacific Ocean are obtained by the ISC and are reported by fishing nation or entity dislaimer, regardless of the area of the Pacific Ocean in which the fish were caught.

U.S. fisheries generally harvest a small fraction of the total Pacific-wide bluefin harvest. The average annual bluefin landings by U.S. vessels fishing in the Eastern Pacific Ocean from 2007 through 2011 represent only two percent of the average annual landings from all fleets fishing in the Eastern Pacific Ocean.

From 2000 through 2011, the U.S. West Coast vessels operating in the Eastern Pacific Ocean (all gear types) landed an average annual catch of 113 metric tons. The figure to the right, from the ISC Pacific Bluefin Tuna stock assessment report, shows historical annual catch of Pacific bluefin tuna by country from 1952 – 2012.

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Economy

The 2012 U.S. landings of Pacific bluefin tuna were worth more than $244,000.

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Recreational

Pacific bluefin tuna are a highly valued species by recreational anglers. Primary West Coast recreational fishing grounds include offshore waters of southern California and northern Baja, and have historically included waters as far north as the 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.

In addition to the commercial harvest, the U.S. recreational fishery caught 456 metric tons of Pacific bluefin in 2011.

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OVERVIEW

Bluefin tuna is the darkest and fattiest of any tuna. Because of its high fat content, bluefin tuna is especially prized for sushi and sashimi. A higher fat content in bluefin tuna is equated with a higher-quality product. Also, because of the high fat content, cooking is not advised as it produces a strong fish taste and odor when cooked.

 
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SEASONAL AVAILABILITY

Year-round, but most Pacific bluefin tuna are caught between May and October.

 
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NUTRITION

Servings 1
Serving Weight 100 g (raw)
Calories 144
Protein 23.33 g
Fat, total 4.9 g
Saturated fatty acids, total 1.257 g
Carbohydrate 0 g
Sugars, total 0 g
Fiber, total dietary 0 g
Cholesterol 38 mg
Selenium 36.5 mcg
Sodium 39 mg

Pacific Bluefin Tuna Table of Nutrition

 

 
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RECIPES

  • Coming soon...

 
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