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Atlantic Bigeye Tuna

Thunnus obesus

Atlantic bigeye tuna

Also Known As

  • Tuna
  • Big eye
  • Ahi-b

U.S. wild-caught Atlantic bigeye tuna—while only a small percent (about 1%) of the total Atlantic-wide harvest—is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.

Measuring a bigeye tuna.Bigeye tuna catch.A fishery observer measuring a bigeye tuna.Bigeye tuna on ice.Bigeye tuna sushi.

Population

Significantly below target population level. The United States is working with other nations to develop an international rebuilding plan.

Fishing Rate

The United States is working with other nations to reduce harvest rates and end overfishing.

Habitat Impacts

Fishing gear used to catch bigeye tuna rarely contacts the seafloor so habitat impacts are minimal.

Bycatch

Regulations are in place to minimize bycatch.

  • Availability

    Year-round.

  • Source

    U.S. wild-caught from Massachusetts to Florida.

  • Taste

    Bigeye tuna has a mild, meaty flavor, with a higher fat content than yellowfin tuna. Sashimi lovers prefer it.

  • Texture

    Firm and moist with large flakes.

  • Color

    Bigeye tuna meat has a reddish-pink color.

  • Health Benefits

    Bigeye tuna is low in saturated fat and sodium and is rich in niacin, vitamins B6 and B12, selenium, and phosphorous.

The U.S. Fishery

Fishery Management

  • NOAA Fisheries and the Atlantic Highly Migratory Species Division manage the Atlantic bigeye tuna fishery in the United States.
  • Managed under the 2006 Consolidated Atlantic Highly Migratory Species Fishery Management Plan:
    • Commercial fishermen must have a permit to harvest bigeye tuna.
    • Gear restrictions.
    • Time/area closures.
    • Minimum size limit.
    • Federal management for Atlantic tunas applies to state waters as well, except in Maine, Connecticut, and Mississippi. NOAA Fisheries periodically reviews these states’ regulations to make sure they’re consistent with federal regulations.
  • Highly migratory species, such as bigeye tuna, have complicated management that requires international cooperation.
  • The United States participates in regional fisheries management organizations, such as the International Commission for the Conservation of Atlantic Tunas (ICCAT), to enhance tuna management worldwide and promote the rigorous stewardship standards followed by our own U.S. fishermen.
  • NOAA Fisheries sets regulations for the U.S. western Atlantic bigeye tuna fishery based on our science as well as conservation and management measures adopted by ICCAT. ICCAT conservation and management recommendations include:
    • An annual total allowable catch of 61,500 metric tons in 2021 allocated among major harvesters, sharing arrangements for member countries, minimum size limits, effort controls, time/area closures, trade tracking requirements, compliance measures, and monitoring and inspection programs.
    • ICCAT remains concerned about unreported catches and is actively working to improve statistics by working with tuna canneries in West Africa.
    • Since 2011, ICCAT has also instituted numerous requirements related to catch reporting and measures to manage the use of fishy aggregating devices.
    • The United States has strongly advocated for management measures at ICCAT to end overfishing and rebuild the stock.  NOAA Fisheries will continue to work with ICCAT to develop effective measures to end overfishing and to implement an international rebuilding program.
  • 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.

Harvest

  • Commercial fishery:
    • U.S. harvest of Atlantic bigeye tuna is usually only a small fraction (1 percent or less) of the global Atlantic bigeye harvest.
    • In 2020, U.S. commercial landings of Atlantic bigeye tuna totaled one million pounds, and were valued at more than $4.8 million, according to the NOAA Fisheries commercial fishing landings database. 
  • Gear types, habitat impacts, and bycatch:
    • U.S. commercial fishermen mainly harvest bigeye tuna using pelagic longlines. They sometimes use rod-and-reel gear.
    • Fishing gear used to catch bigeye tuna rarely contacts the seafloor so habitat impacts are minimal.
    • Commercial fishing gear can catch protected species such as marine mammals and sea turtles.
    • NOAA Fisheries has taken the following additional measures to reduce bycatch, bycatch mortality, and sustainably manage the pelagic longline fishery. Fishermen are:
      • Required to use large circle hooks and certain types of bait that limit gear interactions with sea turtles. Circle hooks are specifically designed to minimize the damage caused by hooking, giving animals that are captured and released a better chance at survival.
      • Trained to use special techniques to safely dehook and release any incidentally caught turtles.
      • Required to stop fishing and move 1 nautical mile if they encounter a protected species.
      • Required to protect pilot whales and Risso's dolphins when fishing in the Mid-Atlantic Bight by limiting the length of their lines to 20 nautical miles and posting marine mammal handling/release guidelines on their vessels. In addition, if fishing in the Cape Hatteras Special Research Area, pelagic longliners must contact NOAA Fisheries at least 48 hours prior to a trip and carry observers if requested.
      • Required to use weak hooks in the Gulf of Mexico to reduce incidental catch of bluefin tuna and prohibited from using live bait to reduce bycatch of billfish.
      • Restricted from certain areas of the Gulf of Mexico to reduce bycatch of multiple species.
      • Required to carry vessel monitoring systems onboard their boats to ensure compliance with these closures.
      • Required to carry at-sea fisheries observers upon request. NOAA Fisheries reviews observer data to monitor protected species interactions and takes appropriate action as necessary.
      • Required to install electronic monitoring (cameras) and submit camera hard drives to NOAA Fisheries to monitor bluefin tuna catch and discards.
  • Recreational fishery:
    • Recreational fishermen must have a permit to fish for bigeye tuna.
    • Minimum size limit.
    • Recreational fishing for highly migratory species such as bigeye tuna provides significant economic benefits to coastal communities through individual angler expenditures, recreational charters, tournaments, and the shoreside businesses that support those activities.

The Science

Population Status

  • According to the 2018 stock assessment, Atlantic bigeye tuna is overfished and subject to overfishing. Summary stock assessment information can be found on Stock SMART.
  • The International Commission for the Conservation of Atlantic Tunas (ICCAT) assesses the abundance of Atlantic bigeye tuna and evaluates the sustainability of current and proposed harvest practices. They use the scientific information from these assessments to make management recommendations.

Location

  • Bigeye tuna live in the tropical and warm temperate waters of the Atlantic, Pacific, and Indian Oceans.
  • In the western Atlantic, they can be found from Southern Nova Scotia to Brazil.

Habitat

  • Bigeye tuna are a highly migratory species, swimming long distances throughout the ocean.
  • They often swim in schools and live at or near the surface but dive into deeper waters (to about 800 feet, deeper than other tropical tunas) during the day.
  • Larvae are found in tropical waters, and as juvenile fish grow larger they tend to move into temperate waters.
  • As juveniles they often school with yellowfin and skipjack tunas at the surface, especially in warm waters.

Physical Description

  • Bigeye tuna are dark metallic blue on the back and upper sides and white on the lower sides and belly.
  • The first fin on their back is deep yellow, the second dorsal and anal fins are pale yellow, and the finlets are bright yellow with black edges.
  • Bigeye and yellowfin tuna look fairly similar. In fact, it’s hard to distinguish the two species without experience.
  • Among other characteristics, the bigeye’s eyes are larger than the yellowfin’s and their finlets have black edges.

Biology

  • Bigeye tuna grow fast and can reach about 5.5 feet in length.
  • They can live up to 9 years and are able to reproduce when they are 3.5 years old.
  • Bigeye tuna spawn throughout the year but most often in the summer.
  • They usually spawn two or more times a year.
  • Females release between 3 million and 6 million eggs each time they spawn.
  • Bigeye tuna feed near the top of the food chain, preying on fish, crustaceans, and squid.
  • They are prey for many top predators, including sharks, billfish, larger tunas, and toothed whales.

Research

  • Skipjack often school around floating objects, including fish aggregating devices (FADs) intentionally placed in the water to attract fish. Foreign purse seiners and baitboats have used FADs extensively in the Atlantic since the early 1990s to catch skipjack, primarily off the coast of West Africa. Researchers have found that the increasing use of FADs has changed the species composition of tuna catches, resulting in a higher capture rate of juvenile yellowfin and bigeye tuna for vessels targeting skipjack. The higher capture rate of juvenile bigeye tuna in purse seine fisheries associated with FADs has been demonstrated by ICCAT to reduce the overall maximum sustainable yield of the stock. The increased presence of FADs may also have an impact on the biology and ecology of skipjack, bigeye, and yellowfin tuna. Also, sea turtles and marine mammals can become entangled in nets, ropes, and lines that are used in the FADs. This research influenced ICAAT’s requirements related to the use of FADs in the bigeye tuna fishery (see management section).

Last updated: 08/27/2021