Bigeye Tuna

Facts

  • Status
    Vulnerable
  • Scientific Name
    Thunnus obesus
  • Weight
    up to 460 pounds
  • Length
    up to 7.5 feet
  • Habitats
    Ocean
school of bigeye tuna

Bigeye tuna are generally the size of yellowfin, and smaller than bluefin. They are long and streamlined, have dark metallic blue on their backs and upper sides, and are nearly white on their lower sides and belly. They can live as long as 15 years. Bigeye are found in the subtropical and tropical areas of the Atlantic (but not in the Mediterranean), Indian and Pacific Oceans.

Why They Matter

  • Bigeye tuna are an important commercial fish, usually marketed as fresh or frozen. Although tuna do provide food and livelihoods for people, they are more than just seafood. Tuna are a top predator in the marine food chain, maintaining a balance in the ocean environment.

Threats

  • Extinction Risk Vulnerable
    1. EX
      Extinct

      No reasonable doubt that the last individual has died

    2. EW
      Extinct in the Wild

      Known only to survive in cultivation, in captivity or as a naturalised population

    3. CR
      Critically Endangered

      Facing an extremely high risk of extinction in the Wild

    4. EN
      Endangered

      Facing a high risk of extinction in the Wild

    5. VU
      Vulnerable

      Facing a high risk of extinction in the Wild

    6. NT
      Near Threatened

      Likely to qualify for a threatened category in the near future

    7. LC
      Least Concern

      Does not qualify for Critically Endangered, Endangered, Vulnerable, or Near Threatened

Bycatch

Juvenile bigeye tuna are increasingly caught as bycatch in skipjack tuna fisheries because they school with skipjack.

Overfishing

Bigeye tuna are prized in Asia for sashimi as well as frozen and fresh in other markets. As bluefin tuna populations shrink around the world, pressure on bigeye fisheries is increasing. According to information collected by the International Seafood Sustainability Foundation (ISSF) Scientific Advisory Committee, overfishing is occurring in Eastern and Western Pacific Oceans.

What WWF Is Doing

Tuna are integral parts of the entire marine ecosystem and our goal is for populations to be healthy and well-managed. We partner with governments and regional fisheries management organizations to advocate for stricter plans to recover depleted tuna stocks, combat pirate fishing and reduce bycatch.

WWF works with other organizations and the fishing industry to transform tuna fishing into a sustainable business, particularly through certification of tuna fisheries by the Marine Stewardship Council (MSC). WWF helps ensure that tuna are harvested responsibly and sustainably managed through work with the International Seafood Sustainability Foundation (ISSF). We encourage retailers to source from fisheries that are MSC-certified and work to raise consumer awareness about sustainably caught tuna.

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