Massively overfished

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 tonnes - way over the annual eastern bluefin tuna quota of 32,000 tonnes, 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 tonnes — 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 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. Turkish fleets, for example, recently began targeting bluefin tuna for the country’s new tuna farms. However under ICCAT regulations, Turkey does not yet have a quota for bluefin 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 tonnes, or 10% 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.

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”.