Atlantic Bluefin Tuna

Bluefin Tuna farm off Cartagena coast, Murcia Spain.
© Jorge SIERRA / WWF-Canon

Tuna “farms”

The farms are actually fattening pens for live-caught bluefin tuna, and supply a new market in Japan for cheaper bluefin tuna for sushi and sashimi. Suddenly, the prized bluefin was affordable for nearly all Japanese, not just the wealthy. Demand soared...and so did the fishing effort.

In 1996, the first tuna farms appeared in the Mediterranean, in the waters off Spain. By 2001, there were 12, in the waters off Spain, Italy, Malta, and Croatia. And by 2005 they had mushroomed to over 40, spreading to Turkey, Cyprus, Tunisia, and Libya.

The farms are now big business. In 2005, an estimated 28,450 tons of bluefin tuna went to the farms - nearly 90 percent of the total allowed annual quota for bluefin tuna for the entire Eastern Atlantic and Mediterranean.

In the Murcia region of Spain, where most farms are located, the value of tuna production increased dramatically from $4.5 million to $155 million in 2002. More than 90 percent of the fattened tuna goes to Japan, whose entire tuna imports were worth a mind-boggling $1.49 billion just from January-September 2005.

Subsidized farms

Fish prepared for bluefin tuna Farm. Port of Cartagena (Murcia - Spain)
© Jorge SIERRA / WWF-Canon

Attracted by the money to be made, private investments have poured into Mediterranean tuna farms. Perversely, the farms are also eligible for EU subsidies for aquaculture (underwater agriculture) development - even though they are not aquaculture, as the tuna are caught from the wild. WWF conservatively estimates that $30 million were distributed to different stages of the Mediterranean EU tuna farming industry between 1997 and 2004.

New boats

Various countries have also taken advantage of EU subsidies to modernize their tuna-catching fleets. Purse seine fleets from France and Spain, the largest suppliers of tuna for farms, have been intensely modernized over the last few years. Older vessels have even been replaced by highly efficient new units, thanks to the generous EU funds all paid for by the European taxpayer. As a result, the fleets’ catching capacity has increased dramatically.

Overfishing

A tuna catch
© WWF

The first concerns about overfishing of Atlantic bluefin tuna came in the late 1960s. But despite various management and conservation measures introduced by ICCAT (International Commission for the Conservation of Atlantic Tuna), overfishing has continued.

The main driver of overfishing of Atlantic bluefin tuna in the Mediterranean today is tuna farming. As of July 2006, the farms’ total capacity was 55,300 tons - way over the annual eastern bluefin tuna quota of 32,000 tons, and a clear incentive for overfishing.

It hardly seems surprising then that the actual catch in 2004 was estimated to be 45,000-50,000 tons — around 1.5 times higher than the quota. Catches in 2005 are thought to be similarly high.

Illegal fishing

Clearly, with catches vastly exceeding the quota, a large percentage of the bluefin tuna catch comes from illegal, unregulated and unreported (IUU) fishing

One problem is that vessels from, or flagged to, countries that are not members of ICCAT (International Commission for the Conservation of Atlantic Tuna) and therefore not bound by its recommendations are fishing for Atlantic tuna.

Illegal and unreported or under-reported catches are also made by ICCAT members. In 1999, the estimated unreported catch of Spain, Croatia, France, Italy, Portugal, and Morocco was 3,242 tons, or 10 percent of the total bluefin tuna quota for the Mediterranean and Eastern Atlantic. In the last two years, around 40% of the total eastern Atlantic bluefin tuna catch was thought to have come from new illegal fishing areas in the Eastern Mediterranean, inside the tuna’s last formerly undisturbed breeding grounds.

Overfishing by ICCAT members is aided by two features of tuna farming. One is that tuna farming is officially considered a post-harvesting practice. This means the farms avoid every regional and international rule set up to manage Atlantic bluefin tuna fisheries.

The second is the practice of transferring live tuna at sea to tug boats for transportation to the farms. This makes it extremely difficult to keep track of how many tuna were caught by who and where, and what size they were.

A school of Northern bluefin tuna (Thunnus thynnus) during their migration in the Mediterranean Sea.
© Brian J. Skerry / National Geographic Stock / WWF

Japan, which imports most of the bluefin tuna captured in the Mediterranean, has strict rules prohibiting IUU fish from entering the country. However, China and other Southeast Asian countries are less strict. Their ports would likely accept illegally caught bluefin tuna from the Mediterranean, and then ship it to Japan as a different product category, such as “ready-to-consume frozen sashimi tuna”.

Caught as youngsters

Adding to the overfishing problem is the extremely high catch of juvenile Atlantic bluefin tuna that have never had the chance to spawn.

Vast numbers were caught in the Western Atlantic for the canning industry in the 1960s. While capture of juveniles has now been drastically reduced in Western Atlantic fisheries, large numbers are still caught in the Eastern Atlantic and the Mediterranean.

According to ICCAT (International Commission for the Conservation of Atlantic Tuna), undersized Atlantic bluefin tuna (less than 6.4kg) have made up 50 percent of catches in the Eastern Atlantic and Mediterranean in recent years. ICCAT believes that large quantities of undersized fish continue to be caught in the Eastern Atlantic and Mediterranean today, including fish less than one year old.

The actual catch of juveniles is even higher. The minimum legal landing size may be 6.4kg (and, since 2004, 10kg in the Mediterranean), but Atlantic bluefin tuna don't reach spawning age until they are at least 30kg.

Juveniles are also caught as bycatch by longline fleets targeting bluefin tuna and swordfish, and in the Mediterranean albacore tuna fishery.