Pacific Blue Marlin

About the Species

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

Status

• According to the 2016 stock assessment, Pacific blue marlin are not overfished and not subject to overfishing.
• Population assessments for Pacific blue marlin are conducted by the Billfish Working Group, a division of the International Scientific Committee for Tuna and Tuna-Like Species in the North Pacific Ocean (ISC). NOAA Fisheries scientists participate in the ISC assessment and contribute relevant U.S. fishery data.

Appearance

• 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.

Where They Live

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

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.
  • These Commissions rely on the scientific advice of their staff and the analyses of the International Scientific Committee for Tuna and Tuna-like Species in the North Pacific (ISC) to develop and adopt international resolutions for conservation and management measures.
  • Working with the U.S. Department of State, NOAA Fisheries domestically implements these conservation and management measures.