Atlantic Yellowfin Tuna (Thunnus albacares)

• Atlantic yellowfin tuna is approaching an overfished condition.
• Atlantic yellowfin tuna are managed both domestically (by NMFS Highly Migratory Species Division) and internationally (by the International Commission for the Conservation of Atlantic Tunas and other organizations).
• Yellowfin is low in saturated fat and sodium and is a very good source of protein, thiamin, selenium, and vitamin B6. For more on nutrition, see Nutrition Facts. (USDA)
• About 25% of all yellowfin tuna sold in the U.S. comes from U.S. fisheries; the rest is imported.

Sustainability Status

Biomass: Atlantic yellowfin tuna is approaching an overfished condition. The biomass of the stock is 73% of the biomass needed to support maximum sustainable yield.
Overfishing: No
Overfished: No
Fishing and habitat: Atlantic yellowfin are caught with longlines, troll gear, pole-and-line, and purse seines. Habitat damage by highly migratory species fishing gear, other than bottom longlines, is minor in the open ocean environment.
Bycatch: Pelagic longlines can incidentally catch bluefin tuna, billfish, undersized target species, marine mammals, sea turtles, seabirds, non-target finfish, prohibited shark species, and large coastal shark species. NMFS has required logbook and observer reporting and implemented several time-area closures and gear modifications to monitor and reduce bycatch in this fishery. Pelagic longline fishermen fishing for HMS must use sea turtle release and disentanglement gear and comply with safe handling and release protocols. Troll-caught yellowfin tuna has very little bycatch.
Aquaculture: There is currently no commercial aquaculture of yellowfin tuna in the United States.

Science and Management

The U.S. fishery for yellowfin tuna in the Atlantic is managed by NMFS Highly Migratory Species Division through the 2006 Consolidated Atlantic Highly Migratory Species Fishery Management Plan. Because yellowfin is highly migratory and fished by many nations, the fishery is also managed internationally by the International Commission for the Conservation of Atlantic Tunas (ICCAT). Several management measures have been implemented in the United States, consistent with ICCAT advice to limit fishing effort and to prevent overfishing. In 1999, NMFS implemented limited access in the pelagic longline fishery for Atlantic tunas, as well as a recreational retention limit for yellowfin tuna. The United States has also maintained its minimum size limit for yellowfin of 27 inches, which is greater than the minimum size recommended by ICCAT (before the organization repealed their recommendation). Yellowfin tuna is listed as approaching an overfished condition by the United States.

Life History and Habitat

Life history, including information on the habitat, growth, feeding, and reproduction of a species, is important because it affects how a fishery is managed.

• Geographic range: In tropical and subtropical oceanic waters.
• Habitat: Juveniles form mixed schools with skipjack and juvenile bigeye tuna and are mainly limited to surface waters. Larger fish are found in surface and sub-surface waters.
• Life span: About 7 years.
• Food: Yellowfin tuna are opportunistic feeders, preying on a wide variety fishes and invertebrates associated with Sargassum, a floating algae.
• Growth rate: Variable with size - relatively slow initially and increasing by the time the fish leave the nursery grounds.
• Maximum size: Up to 400 pounds.
• Reaches reproductive maturity: Most yellowfin are capable of reproduction at the age of 2 or 3 years and around 39 inches in length.
• Reproduction: Female yellowfin are multiple spawners, with an average spawning frequency of 46 times or about one spawn every three days. Females have an average of 1 million to 4 million eggs.
• Spawning season: From May to August in the Gulf of Mexico and from January to April in the eastern Atlantic Ocean.
• Spawning grounds: The main spawning ground is the equatorial zone of the Gulf of Guinea (southwest of Africa). Spawning also occurs in the Gulf of Mexico, in the southeastern Caribbean Sea, and off Cape Verde (off the northwestern coast of Africa).
• Migrations: Yellowfin are highly migratory, moving from west to east across the Atlantic Ocean.
• Predator/prey interactions: Sharks and large bony fishes prey on yellowfin tuna.
• Commercial or recreational interest: Both
• Distinguishing characteristics: Yellowfin tuna are torpedo-shaped fish. They are metallic dark blue on the back and upper sides, changing from yellow to silver on the belly. True to the name yellowfin, their dorsal and anal fins, and finlets are bright yellow. Tuna species are difficult to distinguish. Bigeye, blackfin, albacore, and yellowfin are similar in shape and are often caught together. Characteristics that distinguish the yellowfin from other species are its elongated anal and dorsal fins on large fish, a moderately smooth, nonstriated ventral surface of the liver, and 26 to 34 gill rakers on the first arch.

Role in the Ecosystem

Yellowfin tuna fall into the fourth trophic level in the oceanic ecosystem, as they are carnivores that feed primarily on fish, cephalopods, and crustaceans.

Additional Information

Market name: Tuna
Vernacular name: Ahi

Biomass

Biomass refers to the amount of Atlantic yellowfin tuna in the ocean. Scientists cannot collect and weigh every single fish to determine biomass, so they use models to estimate it instead. These biomass estimates can help determine if a stock is being fished too heavily or if it may be able to tolerate more fishing pressure. Managers can then make appropriate changes in the regulations of the fishery.

A full stock assessment was conducted for yellowfin tuna in 2003. Yellowfin is approaching an overfished condition. The stock will be reassessed in July 2008.

Landings

Landings refer to the amount of catch that is brought to land. Yellowfin tuna is the principal species of tropical tuna landed by U.S. fisheries in the western North Atlantic. Total estimated landings were 6,437 metric tons in 2004, 5,562 metric tons in 2005, and 7,075 metric tons in 2006. A high proportion of these landings are due to rod and reel catches by recreational anglers.

Biomass and Landings

Are landings and biomass related? Landings are dependent on biomass, management measures in the fishery, and fishing effort.

Data sources:
Landings from NOAA Highly Migratory Species Division

Important Dates

Early 1900s – Sport fishery develops off New York and New Jersey
1950s-1960s – Rod and reel fishery expands rapidly along mid-Atlantic coast
1958 – Commercial purse seining for Atlantic tunas begins and expands during the early 1960s
1960s – Pelagic longline fishery for Atlantic tunas develops, comprised mainly of Japanese vessels fishing in the Gulf of Mexico
1972 – ICCAT passes recommendation that prohibited the landing of yellowfin less than 7 pounds due to concern of the high proportion of juvenile yellowfin that are landed
1993 – ICCAT recommends that there be no increase in the level of fishing effort over 1992 levels
1999 – NMFS publishes the Final Fishery management Plan for Atlantic Tunas, Swordfish, and Sharks, the first FMP for Atlantic tunas; measures include prohibition of pelagic driftnets for tunas, implementation of the ICCAT Rebuilding Program, recreational retention limit for yellowfin
2006 – Final Consolidated HMS FMP approved and implemented

Notes and Links

General Information:
Atlantic Tunas Description

International Commission for the Conservation of Atlantic Tunas

Introduction to NMFS Highly Migratory Species Management Division

Fishery Management:
Consolidated Atlantic Highly Migratory Species Fishery Management Plan

Stock Assessments:
2005 Stock Assessment and Fishery Evaluation Report for Atlantic Highly Migratory Species

2003 ICCAT Atlantic Yellowfin Tuna Stock Assessment Session