Bluefin Tuna: No Common Fish

Global Tuna ConservationThe bluefin tuna is one of the largest, fastest, and most streamlined animals on the planet—built for speed and endurance. It can weigh up to 1500 pounds and dive to 3000 feet. It is no common fish.

You won't find bluefin tuna in a can or in a tuna salad. Its deep red flesh is used in sushi dishes and at high-end restaurants. As demand in Japan (the primary import country), Europe, and North America has exploded, fishing and illegal fishing have dramatically expanded to meet that demand.

There are three species of bluefin tuna: Atlantic, Southern, and Pacific.

All are overfished throughout their ranges.

Atlantic bluefin tuna is caught along the eastern seaboard of the United States, in the Gulf of Mexico, in the Mediterranean Sea—and often in between Europe and North America. The Mediterranean bluefin tuna fishery has been under scrutiny for years, due to widespread illegal fishing and historically, quotas set far above what scientists recommend.Click here to learn about the Atlantic bluefin tuna.

Pew is helping to reverse the decline of the Atlantic bluefin tuna, encourage a sustainable fishing industry, and promote the recovery of this majestic species through three key areas:

What should you know about bluefin tuna?

  • There are three species of bluefin tuna: Atlantic, Southern, and Pacific.
  • There are two populations of Atlantic bluefin tuna: the eastern Atlantic and the western Atlantic.
  • Bluefin tuna are migratory—they cross the ocean in search of food and return to spawning grounds to reproduce.
  • Because tuna are highly migratory, fishing countries must jointly manage them. They do this through international organizations like ICCAT.
  • Atlantic bluefin spawn only in the Gulf of Mexico and the Mediterranean Sea.

How are bluefin tuna caught?

  • Purse seines are large, vertically floating nets (made of monofilament or plastic) which boats use to surround schools fish. Each net can be up to one mile long. Once fish are in the net, the base is drawn together, creating a purse. This method captures large volumes of target and non-target fish.
  • Pole-and-line fishing uses hand held or mechanically operated poles with baited hooks attached. This selective fishing method targets naturally schooling fish which are attracted to the surface through use of lights or scattering of bait.
  • The trap fishery, called tonnara in Italian, madrague in French, almadraba in Spanish, and armação in Portuguese, forms and elaborate maze of nets that capture and corral bluefin tuna during their spawning season. Traps have been used in the Mediterranean for thousands of years, but since the rise of industrial purse seine fishing, these traditional and artisanal methods have suffered.
  • Atlantic bluefin tuna are caught by harpoon in New England in the United States. This involves spotter planes helping boats to locate the fish, then the use of a large spear thrown by a single fisherman to capture the bluefin. The type of fishing is very selective.

Bluefin tuna are big business

The global Atlantic bluefin trade is big business—each year, thousands of tonnes of fish are caught, most of them destined for consumers in Japan. But it is not a simple journey from sea to sushi counter.

Young bluefin tuna caught in the Mediterranean are often sent to floating "ranches" where they are held and fattened for up to two years before they are killed, sold, and sent to the market.

During this time, they may be bought and sold multiple times before reaching consumers. Unfortunately, this complicated supply chain provides an opening for fraud and misreporting, and an opportunity for illegally caught fish to enter the supply chain.

Each bluefin that is caught and sold must be accompanied by a paper BCD, or bluefin catch document, that tracks the fish as it moves through the supply chain.

More advanced electronic catch documentation schemes are already in place for Patagonian toothfish (also known as Chilean seabass), an Antarctic fish, and some U.S. businesses use a system that assigns a unique barcode to each fish caught—a more foolproof way to track these valuable fish from vessel to plate.

Mediterranean countries must put in place a similar electronic system to reduce the burden on legitimate fishermen.

Media Contact: Dave Bard

Topics: Oceans, Environment

Project: Global Tuna Conservation