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Pacific Blue Marlin

Makaira nigricans

Illustration of a pacific blue marlin

Also Known As

  • A‘u
  • Kajiki
  • Aguja azul

U.S. wild-caught Pacific blue marlin is a smart seafood choice because it is sustainably managed and responsibly harvested under U.S. regulations.

Population

Above target population levels.

Fishing Rate

At recommended level.

Habitat Impacts

Gear used to harvest blue marlin rarely contacts the ocean floor, so habitat impacts are minimal.

Bycatch

Regulations are in place to minimize bycatch in the tuna and swordfish fisheries, which incidentally catch the most commercially available blue marlin.

  • Availability

    From June through October.

  • Source

    U.S. wild-caught from waters around Hawaii, other U.S. Pacific Islands, and the high seas.

  • Taste

    Rich, full flavor.

  • Texture

    Firm and meaty, similar to swordfish.

  • Color

    Light golden-orange when raw, turns off-white when cooked.

  • Health Benefits

    Blue marlin is low in saturated fat and sodium, and is a good source of vitamin B12, vitamin B6, selenium, niacin, and protein.

The U.S. Fishery

Fishery Management

  • NOAA Fisheries and the Western Pacific Fishery Management Council manage the Pacific blue marlin fishery.
  • Managed under the Fishery Ecosystem Plan for Pacific Pelagic Fisheries of the Western Pacific Region:
    • Entry to this fishery is limited to a maximum of 164 vessels.
    • Permits and logbooks are required.
    • Observers are required on all Hawaii-based longline vessels.
    • NOAA Fisheries vessel monitoring system program requires longline boats to be equipped with a satellite transponder that provides real-time vessel position updates and tracks vessel movements.
    • Longlines are prohibited in certain areas to protect endangered Hawaiian monk seals and reduce the potential for gear conflicts and localized stock depletion.
    • Vessels operating under longline general permits must carry special gear to release incidentally hooked or entangled sea turtles.
    • Fishing gear requirements apply to all Hawaii longline limited access permitted vessels. The requirements may change depending on type of fishing trip, location of fishing, and how the gear is set. An overview of gear requirements can be found here.
  • Management of highly migratory species, like Pacific blue marlin, is complicated because the species migrate thousands of miles across international boundaries and are fished by many nations.
  • Effective conservation and management of this resource requires international cooperation as well as strong domestic management.
  • Two organizations, the Inter-American Tropical Tuna Commission (IATTC) and the Western and Central Pacific Fisheries Commission (WCPFC) manage this fishery internationally.

Harvest

  • Commercial fishery:
    • Marlin are primarily caught incidentally in pelagic longline commercial fisheries for tuna and swordfish. They are also a popular target fish for recreational fishermen.
    • In 2016, commercial landings of Pacific blue marlin from the waters around Hawaii totaled more than 1.5 million pounds and were valued at more than $2 million.
    • The Billfish Conservation Act, along with existing billfish regulations, prohibits the sale and commercial possession of billfish and billfish products. However, those that are caught in Hawaii and the Pacific Insular Areas (which includes American Samoa, Guam, and the Northern Mariana Islands) are exempt and can be sold.
  • Gear types, habitat impacts, and bycatch:
    • U.S. pelagic longline fishermen who target tuna and swordfish may incidentally catch blue marlin.
    • Fishing gear used to catch tuna and swordfish rarely contacts the seafloor so habitat impacts are minimal.
    • Restrictions on the type of fishing gear that can be used, and prohibitions on fishing in certain areas, minimize impacts on protected species.
    • Interactions with protected species such as sea turtles, marine mammals, and seabirds in these fisheries are rare and survival rates are estimated to be high for all gear types.
    • Longline fishermen are trained in safe handling and release techniques for sea turtles, seabirds, and marine mammals, and they carry and use specific equipment for handling and releasing these animals.
    • Scientists and managers continue to monitor bycatch in these fisheries through logbooks and fishery observer programs.
  • Recreational fishery:
    • Blue marlin are a favorite target for recreational fishermen, as the fish tend to put up an incredible fight when hooked.
      • Hawaii hosts one of the largest billfish tournaments in the United States. Most fish caught in recreational tournaments are tagged and released.
      • There is little bycatch associated with the recreational fishery.

    The Science

    Location

    • Blue marlin live throughout tropical and subtropical waters of the Indian, Pacific, and Atlantic Oceans.

    Habitat

    • Blue marlin prefer warm surface waters that are well mixed by surface winds and are uniform in temperature and salinity. They are considered the most tropical of all billfishes.
    • They spend all of their time in the water column, frequently moving between the surface and a depth of 100 meters. Depth distribution is limited by low water temperature and low oxygen levels.

    Physical Description

    • Blue marlin are deep cobalt blue on top and silvery white on the bottom.
    • They have a pronounced dorsal fin and a long, spear-shaped upper jaw (bill).

    Biology

    • Blue marlin may grow to be more than 12 feet long and may weigh up to 2,000 pounds.
    • Female blue marlin grow larger than males and may live 20 years.
    • Male blue marlin reach 7 feet in length and may live up to 10 years.
    • They grow fast and may reach 3 to 6 feet in the first 1 to 2 years of life.
    • Males mature around 2 years old, and females mature between 3 to 4 years old.
    • Blue marlin spawn between May and September.
    • They eat mostly tuna and other open water fishes.

    Research

    • Researchers at Stanford University and the International Game Fish Association are investigating the movements of marlin through what they call the Great Marlin Race.
    • The Global Tagging of Pelagic Predators program is an international collaborative effort that tracks the location of predators (such as marlin and sharks) in the ocean to better understand how to protect these pelagic animals.
    • Ageing the Grander Blue Marlin
    • Age validation of a Grander Blue Marlin using bomb-produced radiocarbon dating confirms previous estimates that these fish grow very rapidly and to great sizes.

    Last updated: 05/30/2018