Yellowfin tuna is available fresh, frozen, and canned. Canned yellowfin tuna is marketed as "light" tuna and is slightly darker than albacore. While yellowfin tuna quality is difficult to determine due to subjective criteria, number 2 quality is usually adequate for the U.S. market while Number 1 quality is primarily exported to Japan. Fresh and frozen yellowfin is sold to foodservice operators as loins and steaks. Early fall is a good time to buy fresh yellowfin tuna, as demand drops and landings are normally still quite good. Frozen yellowfin is commonly treated with carbon monoxide or tasteless smoke to prevent the red color of the fish from going brown. If abused, carbon monoxide can be used to enhance the color of lower grade yellowfin. However, fresh yellowfin loins and steaks are rarely treated with carbon monoxide to maintain color.
Key sustainability sourcing notes for yellowfin tuna based on landings data from 2014-2015 and the most recent 2014-2016 Seafood Watch assessments and 2011-2016 MSC certifications (four fisheries):
~10% of global yellowfin tuna landings are MSC-certified
~35% of global yellowfin tuna landings (non-FAD/floating object purse seine-caught from the W. Central Pacific and E. Pacific stocks ~85%) and ~85% of U.S. yellowfin tuna landings (Hawaii ~50%, Louisiana ~20%, Florida and North Carolina ~10% each) meet a Seafood Watch "Good Alternative (yellow)" rating
~40% of global yellowfin tuna landings meet a Seafood Watch "Avoid (red)" rating (FAD/floating object purse seine-caught from the Western Pacific and wild-caught from the Indian Ocean ~85%)
~25% of global yellowfin tuna landings are unknown/unrated (~50/50 from W. Pacific and Indian Ocean stocks)
% of landings of yellowfin tuna stocks is W. Central Pacific ~45%, Indian O. ~30%, E. Pacific ~20%, and Atlantic O. ~5% Estimated global landings of yellowfin tuna by gear type is ~25% purse seine - unassociated / free-schooling, ~25% purse seine - fish-aggregating device (FAD), ~20% unknown, ~15% longline, ~10% purse seine - dolphin-set, ~5% gillnet, and ~2% pole and troll
Global yellowfin tuna landings in 2015 were nearly identical to 2014 and U.S. landings decreased ~20% from 2012 to 2015
Yellowfin tuna are distinctive from other tunas by their long, bright yellow dorsal fin and yellow stripe down the side. They are also more slender than bluefin tuna and their torpedo-like shape allows them to reach speeds up to 50 miles per hour (80 km per hour). Tunas have hearts that are ten times larger for their body weight, pump three times more blood, and have blood pressure three times higher when compared to less active fish species. These factors allow them to maintain faster speeds for farther distances.
By folding their fins into special indentations, yellowfin tuna are able to streamline their bodies to swim faster. Their blood has a counter-current heat exchanging system, and high oxygen affinity and capacity for oxygen offloading, allowing yellowfin tuna to maintain a comfortable body temperature and a regulated metabolic rate in cold and oxygen deficient waters.
Yellowfin tuna grow quickly, and can reach up to seven feet in length (about two meters) and can weigh up to 400 pounds. However, tuna that are caught most often weigh around 80 pounds, with some weighing upwards of 200 pounds. They have a relatively short lifespan, living for about seven years. They reach maturity between ages two and three years, when they measure around three feet in length (about one meter).
Spawning season of this species occurs year-long - with a peak in the summer - over a wide area of tropical and subtropical oceans, as long as certain environmental conditions (i.e. water temperature and forage availability) are suitable. Females spawn every three days during peak spawning season, producing an average of one to four million eggs each time. As is believed with other tropical tuna species, environmental conditions are thought to greatly influence recruitments levels for yellowfin tuna.
Yellowfin tuna feed near the top of the food chain on fish, squid, and crustaceans. Fish, seabirds, and other animals eat juvenile and larval yellowfin tuna, while top predators, such as sharks, large fish, and marine mammals prey on adult tuna.
Yellowfin tuna are open-water pelagic and oceanic species. They are highly migratory and can swim across entire oceans. They are found in the subtropical and tropical areas of the Atlantic, Indian and Pacific Oceans. Yellowfin tuna have geographic limits from 45°- 50° N and South, although in the Pacific they occur mainly from 20° N and South. In the eastern Pacific, this species ranges from southern California and the southwest and central eastern parts of the Gulf of California to Peru, including all of the ocean islands. They are sensitive to low concentration of oxygen and are not usually found below a depth of 820 feet (250 meters) in the tropics. Yellowfin tuna prefer waters between the temperatures of 65℉ to 88℉ (18-31°C). Larval distribution is transoceanic, but seasonal changes can affect larval density in subtropical waters. It is believed that larvae occur only in warm water above the ocean’s thermocline. Schooling occurs more commonly in near-surface waters. Juvenile yellowfin tuna travel in schools with skipjack and juvenile bigeye tuna. The species forms adult schools (both free and associated) of similarly sized individuals. The free swimming schools tend to contain larger tunas and are generally mono-specific. Association with floating debris and other objects has also been observed. Some associated schools found in the eastern Pacific contain dolphin pods.
Science & Management
NOAA Fisheries scientists continue to research ways to improve the methods used to assess the yellowfin tuna population. Collaborative efforts with Texas A&M University help evaluate the species’ habitat use, and work with the International Commission for the Conservation of Atlantic Tunas (ICCAT) helps scientists to better understand the lifecycle and migration patterns of Atlantic and tropical tuna species. Started in 2015, ICCAT’s Atlantic Ocean Tropical Tuna Tagging Programme (AOTTP) will spend five years tagging important skipjack, bigeye, and yellowfin tuna stocks in tropical Atlantic waters. The data from this program will be used to improve stock assessment parameters, as well as contribute to food security and economic growth of the Atlantic coastal states internationally by ensuring sustainable management.
Scientists at NOAA’s Southwest and Pacific Islands Fisheries Science Centers contribute to research on Pacific tropical tunas by monitoring US fisheries, conducting stock assessments, and participating in international forums for the assessment of these species. NOAA’s Pacific Islands Fisheries Science Center initiated the Pacific Tuna Tagging Project (PTTP) in 2006 to tag and release skipjack, yellowfin, and bigeye tuna throughout the western and central Pacific Ocean. The goal of the PTTP is to improve stock assessments, and better understand the status of the stocks and tuna movements.
A 2010 study published by NOAA found that tuna and billfish populations are more vulnerable to fishing pressure because of shrinking habitat. An expanding hypoxic zone (an area of low oxygen) in the Atlantic Ocean is decreasing oxygen-abundant habitats, forcing the species into shallower waters where they are more vulnerable to predators and fishing. Hypoxic zones occur naturally in tropical and equatorial oceans; however, these zones will continue to expand and increase in number as sea temperatures rise. Higher water temperatures absorb less oxygen, and climate change will increase the expansion of hypoxic zones in the world’s oceans. Fish species such as yellowfin tuna that prefer oxygen rich habitats will move to shallower areas, increasing their catch rates, and giving the appearance of a greater abundance than what actually exists, thus affecting population and stock assessments.
Researchers at the Ocean Science Series of the PEW Environment Group found in 2011 that increasing the use of fish aggregating devices (FADs) changes the species composition of tuna catches. Vessels targeting skipjack tuna will also catch a large amount of juvenile yellowfin and bigeye tuna. This impacts the biology and ecology of skipjack, bigeye, and yellowfin tuna, as younger individuals are being caught and the population is not able to replenish itself.
In the United States, Atlantic tunas - bluefin, bigeye, albacore, and yellowfin - are managed by both the Magnuson Stevens Act and the Atlantic Tunas Convention Act (ATCA). ATCA authorizes the Secretary of Commerce to implement binding recommendations made by the International Commission for Conservation of Atlantic Tunas (ICCAT) - one of several regional fishery management organizations (RFMOs) charged with managing highly migratory species (HMS) by the United Nations Law of the Sea. The management authority for US Atlantic tuna fisheries belongs to the National Marine Fisheries Service’s HMS Management Division. Management measures put in place by the HMS division include quotas, permit programs, and size limits.
On the West Coast of the United States, the Pacific FIshery Management Council developed a Fisheries Management Plan (FMP) for HMS species, including yellowfin tuna. General management measures in this FMP include gear restrictions, fishery observer programs, and quotas and harvest guidelines. For Pacific yellowfin tuna on the high seas, the US is a member of the Inter-American Tropical Tuna Commission (IATTC) RFMO and carries out the recommendations for management measures put forth by the organization.
For yellowfin tuna fisheries on the high seas, stocks are differentiated into four distinct groups that are assessed and managed by RFMOs: Atlantic Ocean, Eastern Pacific, Western Pacific and Indian Ocean. The RFMOs that manage yellowfin tuna stocks on the high seas are ICCAT, IATTC, the Indian Ocean Tuna Commission (IOTC), and the Western and Central Pacific Fisheries Commission (WCPFC).
ICCAT has made several management recommendations to its members with regard to yellowfin, bigeye and skipjack tuna. The Atlantic Ocean Tropical Tuna Tagging Programme (AOTTP) was established in order to gather more information on stock structure, natural mortality and growth for yellowfin tuna and other tropical tuna - all of which is important for stock assessments. Members must also implement a multi-annual management and conservation program for vessels harvesting yellowfin and bigeye tuna. As part of this multi-annual program, a total allowable catch of 110,000 t for yellowfin tuna has been set which is to remain in place until a change is made by the commision based on scientific advice. Additionally, area/time closures meant to protect juvenile tuna have been put into place through this program. FAD use has also been limited to 500 FADs per purse seine vessel. ICCAT members must also submit management plans for their vessels that use FADs and vessels must collect and report information on all FADs they deploy. The commission has established and maintained records of all tropical tuna vessels authorized by ICCAT members - members must keep their lists up to date and report any changes to the commission. If IUU activity is detected, the commission will alert members accordingly, who then must investigate the situation and stop fishing activity, if appropriate. Recommendations have also been made to increase scientific observers onboard vessels fishing for tuna species and information collected from observer programs are compiled by ICCAT and made available at annual meetings.
In recent years, IATTC has established several management measures for tuna in the eastern Pacific Ocean. A measure was implemented to collect vessel information for all vessels harvesting HMS in the eastern Pacific Ocean (area under IATTC’s Convention). The register is meant to assist the IATTC in monitoring and compliance efforts and in 2002, was made the authoritative source of identified purse seine vessels qualified to fish for tuna in IATTC’s Convention Area. A bycatch reduction program for purse seine vessels was also initiated in 2004. Under this program, vessels were required to retain and land all tuna brought on board and to release non-tuna species such as sea turtles that get caught purse seine nets. The program was meant to push for the development of gear or techniques that will reduce the amount of low-value tuna, such as small yellowfin, brought on board so that vessels would not be economically disadvantaged by the full retention program. Member countries also require purse seine vessel operators to maintain logbooks of catch and efforts and must make them available to fishery officials for inspection. In 2016, IATTC adopted a harvest control rule (HCR) to prevent fishing mortality of tropical tunas from exceeding MSY levels. If fishing mortality or spawning biomass approaches a set limit, the HCR also triggers an initiation of additional management measures meant to further reduce fishing mortality to help rebuild the stock. The measures established by the HCR include an annual fishing closure for purse seine vessels with a carrying capacity of 182 tons or more. In addition, this measure calls for a 1) seasonal closure of a purse seine fishery in an area west of the Galapagos Islands known as “El Corralito” where catch rates of tuna are high, 2) a full retention requirement for all purse seine vessels, and 3) a total annual catch limit of the average level observed during 2013-2015 for yellowfin and bigeye tuna (combined).
In the Indian Ocean, yellowfin tuna is addressed in several management measures adopted by the Indian Ocean Tuna Commission (IOTC). A recent resolution passed by the IOTC focuses on rebuilding the Indian Ocean yellowfin tuna stock through the various catch limit requirements for purse seine, gillnet, and longline fisheries. In addition, this resolution also requires that IOTC members monitor yellowfin tuna catches from their vessels. The Compliance Committee will use this monitoring information to evaluate compliance with required fishing reduction levels. There is also currently a ban on discards of yellowfin, skipjack, and bigeye tuna caught by purse seine vessels in the IOTC’s area of competence. This retention requirement states that all tuna caught must be retained on board and landed in order to reduce the amount of species discarded by purse seine vessels. To also reduce the amount of juvenile yellowfin tuna mortalities caused by FAD fishing efforts, the IOTC has moved forward with limiting the number of FADs that can be used by vessels. Members are also required to submit FAD Use Management Plans to the Commission which should include initiatives or surveys to investigate and minimize the capture of yellowfin and bigeye tuna. The IOTC’s Working Party on Tropical Tuna (WPTT) has also made recommendations that catches of yellowfin in the Indian Ocean should not surpass 300,000 t in order to bring the stock biomass levels that could sustain catch at the MSY level in the long term.
The objective of management measures established by the WCPFC for yellowfin tuna is to ensure that rate of fishing mortality does not affect the tuna stock’s ability to achieve maximum sustainable yield. Currently, members of the commission (China, Indonesia, Japan, Republic of Korea, Taipei, and the USA) are encouraged to reduce fishing mortality on juvenile yellowfin tuna in their territorial seas. Members also must establish effort/catch limits for purse seine fisheries in their EEZs that reflect the distribution of yellowfin tuna. For purse seine fisheries, members agree not to increase catches of their vessels harvesting yellowfin tuna. In 2014, members were required to have develop management plans for use of FADs by their high seas vessels which were to include strategies to limit the capture of both bigeye and yellowfin. Members are required to promote research to identify ways to avoid capture of juvenile tuna species during FAD sets and results must be presented annually to the Commission.
Yellowfin tuna is widely distributed throughout tropical and subtropical oceans. They are highly fecund with a moderate lifespan, making them fairly resistant to fishing pressure. A Seafood Watch report from 2014 stated that there is uncertainty about yellowfin tuna populations in the Atlantic as well as some indication that they are overfished and unsustainably fished. Seafood Watch also reported that yellowfin tuna are overfished in the eastern Pacific Ocean but healthy in the western and central Pacific. In the Indian Ocean, yellowfin populations are healthy and fishing mortality rates are low.
Habitat impacts (Wild)
Yellowfin tuna are caught in fisheries that target other tuna species. Slightly more than half of all tuna landed worldwide, including yellowfin, is caught with purse seines that have minimal impacts on ocean habitats. However, anchored fish aggregating devices (FADs) could result in contact. The pelagic longlines, trolls and poles used to catch yellowfin tuna also present a low risk to the seabed and bottom habitats, according to Seafood Watch.
With the exception of the troll, pole and handline fisheries, bycatch in yellowfin fisheries is high. Unintended catch includes threatened and endangered marine mammals. Dolphins, sea turtles, sharks, other tuna, marlin, manta rays, wahoo, stingrays and juvenile tunas are among the bycatch, which is increased with the use of fish aggregating devices (FADs). Longline tuna vessels in the Atlantic are required to collect and report bycatch and discard information. They must have equipment for the safe handling, disentanglement and release of sea turtles, and the captain must be trained on correct techniques.
Starting in 2013, countries in the Atlantic that have not reported shortfin mako shark catch data are prohibited from catching them, according to a 2014 Seafood Watch report. Although fishermen back down purse seine nets for dolphins to escape in the eastern Pacific, the animals can still die from net canopy collapses and stress. The deaths are declining but dolphin populations haven’t yet recovered.
Yellowfin are managed by several fishery management organizations worldwide. The International Commission for the Conservation of Atlantic Tunas (ICCAT) manages them in the Atlantic. ICCAT’s tuna conservation and management program was amended in 2011 to include yellowfin but recovery plans have not been in place long enough to judge their success. Seafood Watch rated the Commission’s bycatch strategy “ineffective” because it doesn’t meet best practices. In addition, there are no bycatch cap or catch limits.
Yellowfin tuna are managed in the U.S. and Canadian longline fisheries by the National Marine Fisheries Service and Fisheries and Oceans Canada. While Seafood Watch rated most of the management strategies as moderately effective, the bycatch strategy was called ineffective in the Canadian North Atlantic longline fishery because it does not require best practices for reducing incidental shark capture. Observer coverage was also lacking.
In the Pacific, the Inter-American Tropical Tuna Commission (IATTC), the Western and Central Pacific Fisheries Commission (WCPFC), the Western Pacific Regional Fishery Management Council (WPRFMC) and the state of Hawaii all manage tuna. Management measures in the western and central Pacific Ocean longline fishery, including ones mitigating bycatch, were rated moderately to highly effective in a 2014 Seafood Watch report. However, management in the eastern Pacific longline fishery did not meet best practice requirements and scientific advice was not always followed, according to a separate report.
Seafood Watch rated the management in the western, central and north Pacific yellowfin purse seine fishery between ineffective and moderately effective. The WCPFC lacks limits on the number of FAD sets allowed annually.
The Indian Ocean Tuna Commission (IOTC) and the Sri Lankan Ministry of Fisheries and Aquatic Sciences manage tuna in those regions. The management was given a red score by Seafood Watch due to a lack of measures to improve monitoring, a lack of total allowable catch, lack of bycatch data as well as poor bycatch mitigation. Seafood Watch also pointed to IUU fishing issues in the Indian Ocean.