It's been a bad few weeks to be an Atlantic tuna with the predictions of species extinction within the next few decades. ICCAT, the International Commission for the Conservation of Atlantic Tunas has been meeting over the past fortnight to decide upon the quotas for the world's tuna fisheries and has been announcing large cuts to fishing quotas, cuts that are designed to give the tuna a 50% chance that their stocks will recover by 2023. It's a flip of the coin as to whether Atlantic tuna will be dead in the next decade and a half rather than a serious move to ensure the survival of this pelagic predator. Charles Clover in The Times questions the math:

Wouldn’t a 95% probability of recovery have been a better objective? Well, yes, but this is Iccat. The plan was clearly designed to ensure that its members could go on fishing. Dr Gerald Scott, Iccat’s chief scientist, revealed that achieving the recovery plan with any certainty would require the bluefin quota for next year to be set nearer to 8,500 tons than the 15,000 tons that many at the meeting thought they could get away with.

Some of the fishing nations — including Libya and even Japan, the biggest tuna-consuming nation — have begun to discuss whether it would be easier to stop fishing than try to enforce an 8,500 quota on 20 fishing nations that is open to fraud. A joint United States-Japanese proposal has emerged, testing the water for a total closure of the bluefin fishery.

The tuna fishery is a classic tragedy of the commons where individuals acting in their own rational self interest destroy a shared group resource. There has been some promising research into farming the species but there is still the underlying problem of feeding them.

Tuna are difficult (but thanks to some research from University of the Sunshine Coast in Queensland , not impossible) to breed in captivity. Currently, most tuna farms capture tuna from the wild, then fatten them up in offshore pens rather than breeding them. This may be set to change and a step in the right direction towards complete sustainability. But the problem with tuna is that they will never be as sustainable as other fish unless they can be conned into eating plant matter.

The feeding problem is simple - tuna eat other fish. Tuna aquaculture is a little like keeping a pen full of sea-going lions alive: you've got to pour in plenty of otherwise edible meat to grow a relatively small amount of luxury meat. (It is however socially unacceptable to farm lions for the purposes of eating or keep them in open water for extended periods). The small baitfish that get fed to tuna could be eaten by humans but poor grade sardines are just not as sexy or tasty as a fatty slab of tuna belly. Herein lies the cultural problem - should we forgo tuna and eat something less palatable to ensure their survival?