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% 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.