By Stephen Dowling
BBC News Magazine
Bluefin tuna - the staple of sushi boxes the world over - is on the brink of extinction, with its plight highlighted in a new film. Sandwich seller Pret A Manger is changing its stance on tuna, but should the rest of us follow suit?
The bluefin tuna is one of the world's most impressive fish - a predatory cruiser of the open ocean that can zoom through the sea at the rate of 40mph and grow to the size of a small car.
The bluefin has become the unwitting star of the campaign to end overfishing. The End of the Line, a documentary based on a book by journalist Charles Clover, examines the mismanagement of bluefin fisheries as a microcosm of how we are hoovering the seas of their fish.
The bluefin is particularly prized in Japan. And the explosion in the market for sushi - which 25 years ago was a relative rarity outside Japan - has created a global market for the three species of bluefin, as has the taste for omega-3-rich tuna steaks to be pan-fried or thrown on a barbecue.
"Bluefin tuna has become the poster boy for the overfishing campaign. It's on the buffers - it's really on the slide down now," Clover says.
"There are no large tuna anymore. There were bluefins of 250lb in Japanese fish markets when I went there four years ago - there are none now. A third of the catch is undersize."
1. Fish shoals are encircled by a large "wall" of net
2. Net is closed off at base, like a purse
3. Fish captured along with a bycatch of non-target species, including bluefin and dolphins
The backlash against those selling bluefin has already begun - a raft of celebrities, including actress Charlize Theron and Sting, have barracked high-end fusion restaurant chain Nobu for still offering the critically endangered bluefin - some have likened it to offering a dish made of tiger or white rhino.
Let's be clear - bluefin is not the tuna you add to your jacket potato or rustle up a tuna pasta bake with. The tuna that finds its way into cans is usually the much more common skipjack variety.
But even the catching of skipjack impacts on the bluefin. Skipjacks are caught using purse-seine nets, which encircle an area before being pulled together in the shape of a purse.
Rod and line
"The trouble is," Clover says, "the skipjack run with all these other tuna species, like bigeye and bluefin. The skipjack are close to the surface and the bluefins swim further down, so there is often bluefin bycatch."
The solution may be to buy canned tuna which is caught by pole and line - fishing vessels with rods and lines. This method is much less wasteful, with fewer fish dying from bycatch - and underage fish can be returned to the sea.
Bluefin tuna - too valuable to ignore for fishermen
Clover's film, which had its premiere in the UK on Monday, has already had an effect on another high-street name, the Pret A Manger sandwich chain. Co-founder Julian Metcalfe was so incensed when he saw the film he made the chain change its policy on tuna.
Out went the yellowfin tuna from the sushi - less endangered than bluefin, but still overfished. The tuna and cucumber sandwiches are - from July - to use only supplies from a sustainable rod-and-line fishery from the Maldives, says the chain's head of sustainability, Nicki Fisher.
"Our skipjack was dolphin-friendly but was still caught by purse seine nets. The dolphins could get out of the nets, but the sharks, the turtles and the bluefin couldn't. Seeing the film has really galvanised us into action."
Other supermarkets have also been taking action.
Marks & Spencer made its big announcement on Tuesday, boasting it is the first of the supermarkets to switch to pole-and-line-caught tuna, not just with fresh and canned but also in sandwiches and salads. The retailer sells 20,000 tuna sandwiches per day.
Sainsburys switched a while back to using pole-and-line-caught for all own brand canned and fresh tuna, while Morrisons says all own brand fresh, and some canned, is pole-and-line. Waitrose is introducing an own brand pole-and-line canned range and Co-op has 60% of its own brand as pole-and-line, Greenpeace says.
Environmental groups have hit out at the mismanagement of the fishery
But the environmental campaign group has criticised the two big tuna suppliers Princes and John West for not making the switch.
"John West tuna is largely made of skipjack tuna caught using a combination of pole-and-line and purse seine fishing. Global stocks of skipjack are scientifically recognised as being healthy and are not overfished," says John West board member Adolfo Valsecchi.
Mr Valsecchi suggests the firm does its utmost to minimise bycatch and promote sustainability in both purse seine and pole-and-line fishing.
Moving to pole-and-line across the skipjack market would help eliminate the issue of bluefin killed because of bycatch, but it would not get rid of the wider problem.
Efforts to regulate the fishery in the Mediterranean - where the Atlantic population of bluefin migrates to spawn - have failed because the Sicilian and Neapolitan mafias have a stake in the fisheries, and have little compunction about putting profit ahead of sustainability. Illegal tuna worth more than $6bn (£3.2bn) is thought to have made its way to Japanese markets in the 20 years up to 2006.
Also, tuna spend their life on the move, and range over a number of territorial waters to and from spawning grounds, which has made the management of the fishery by the likes of the European Union so difficult.
Giles Bartlett, the fisheries officer for the Worldwide Fund for Nature (WWF), admits that while the WWF was able to make an icon of some endangered animals, like the panda, a fish may be a more difficult sell.
"That's the real challenge we face. What we try and do is link it to everything else in the sea, like turtles and whales and big sharks," he says. "It's not just about sustainable fishing, it's about how we look after the oceans as well."
What Mr Bartlett says will save the bluefin is a better fisheries management system - at the moment the Mediterranean fishery continues to fish thousands of tonnes more each year than even the International Commission for the Conservation of Atlantic Tunas (ICCAT) scientists say is allowable.
He says centralised management, with quotas revised once a year, will not work. Fishermen have to agree quotas, and have the flexibility to manage them over five or 10 years.
For the moment, though, sushi lovers cannot look forward to a guilt-free portion of bluefin.
Below is a selection of your comments.
The final line of the piece on bluefin tuna sums it up for me. Using the phrase for the moment suggest there is some hope for the bluefin tuna, and for me, as a fisheries scientist and someone who has worked with fisheries all over the world I can't see that happening. I don't believe there will ever be a time when guilt free bluefin will be available, certainly not in my lifetime. The problem is there is too many vested interests for the politicians in the EU making the decision. They don't police it because they want the votes or are scared to upset the fishermen (like the scenes from the cod closure). It seems that the lessons learned from the cod in Canada have not been learned.
Will it take the extinction of one of the most beautiful and perfectly evolved marine fish species before sensible fisheries management is implemented across the world? The fact that some scientists believe bluefin tuna has already collapsed and that the actual catch is almost 6 times what should really be taken suggests this species will be added to the list currently populated by the dodo, the great auk and other species man's greed has been responsible for making extinct.
Adam Payne, Oxford, UK
As a marine biologist, it is heartening to see major supermarket chains starting to take note of these issues and changing their approach to sourcing fish. I hope that the message also trickles through to those companies who still think it is acceptable to carry on serving and selling fish that are either endangered, or are part of an unsustainable fishery.
This movie, End of the Line, along with the award-winning Sharkwater, should be made compulsory viewing by the government at all schools across the UK. How difficult would that be? That's how we should get the message out there and the plight of the oceans into our children's consciousness.
Sophia Butler-Cowdry, London, UK
No, if you catch tuna with a pole and line you tend to snag sea birds, that's why albatross numbers are plummeting faster than a gannet after a mackerel. There is no easy, sustainable way of catching these fish, so stop it, we're not going to die of starvation.
Paul Braham, Ringwood UK
I have not yet seen the 'End of the Line' documentary, but having read this article and a few other similar items recently, I will be cutting bluefin and yellowfin tuna out and only eating pole and line caught skipjack tuna from now on. What really bothers me is that without the sort of media attention that this story and similar have had, people are not in a position to make an informed decision about whether or not to eat, buy or use a certain product. Scientific information of this sort should be available for all types of product that have an environmental impact of one kind or another, to enable consumers to make informed choices. The big chicken debate last year was a similar situation, albeit higher profile - without knowing what really goes on how can we be in a position to take steps as consumers to try and change it?
Duncan Paine, Cheshire, UK
Well we're back to the age old problem of too many human mouths to feed, fishermen being a bit over greedy maybe, but there again, human population drives the demand. Cuts in human population will create a better wildlife\human balance and therefore stories like this won't need to be written. There are something like 6 billion people on the planet which with today's technologies is about 2-3 billion too many. The numbers are unsustainable.
The only way to police our seas is to incorporate an international fish regulation policy. This must be backed by all governments or fishermen will not listen. We must learn from the Canadian cod lesson. Naval backing may even be necessary where rogue fishermen are concerned. Adhere to the regulations or face stern action.
It isn't really true to say that bluefin is a staple of sushi boxes. It has been a rarity for some time now, and only available at the most expensive sashimi restaurants. The tuna you get in most high street sushi restaurants is usually yellowfin, perhaps albacore. Regardless of what the cannery companies say, tuna is on its way out. You'll notice that it will gradually get more expensive until it is eventually given blanket protection. Sadly that will be after the fishery has collapsed.
Simon Rogerson, London
The basic problem is that there are too many of us, and the planet is simply not big enough to provide us all with what we need to eat. We are about to do an Easter Island, but on a much grander scale.
Nigel Dyer, Harpenden