The environmentally sound search for sushi alternatives

Sushi's main ingredient, the bluefin tuna, faces extinction. Alice Klein looks for a greener option

What did you have for lunch today? Was it a sandwich at your desk? A supermarket salad? Did you eat in the work canteen? Or were you one of the growing numbers of Britons who reached for the sushi?

What did you have for lunch today? Was it a sandwich at your desk? A supermarket salad? Did you eat in the work canteen? Or were you one of the growing numbers of Britons who reached for the sushi?

Over the past five years sushi consumption in Britain has exploded. Neatly packaged maki rolls are now almost as common a sight as sandwiches on the supermarket shelves, and almost all of our high-street sandwich outlets now offer customers a sushi selection - albeit a selection which as often as not contains "no raw fish".

Low in fat, sushi is popularly considered to be the healthy option when it comes to convenience food. But one fact about sushi remains rather unappetising: the prime ingredient, the bluefin tuna, is teetering close to extinction.

The growing popularity of sushi has precipitated a global crisis in stocks of the fish, so much so that less than 5 per cent of the original southern bluefin stock remains in the ocean. The species is now classified as "critically endangered" on the International Union for the Conservation of Nature list.

Loyal to the Japanese tradition, and often ignorant of the paucity of stocks, many British sushi restaurants use the belly of the bluefin for its rich texture and flavour. "We use bluefin tuna because it has a nice, bright colour and a good taste," says a spokesperson for the Japanese restaurant K10 in London. Other favourites in the capital, including Zuma, Sumosan, Miyabi and Satsuma, also say that they use bluefin tuna in their sushi and sashimi.

So, can the discerning sushi lover still have his maki and eat it? To an extent - as long as they are prepared to swap the prime bluefin for a slightly less endangered alternative. Many restaurants have already made the decision for us. Caroline Bennett, the managing director of the sushi chain Moshi Moshi, took bluefin tuna off the menu five years ago when routine inquiries into an irregular supplier led her to discover why the prized bluefin tuna were not materialising. "I started investigating it and, with the help of someone at Greenpeace, realised that bluefin tuna just wasn't there. Over-fishing had caused the catch to decrease from 800,000 tons in the 1950s to 40,000 tons today," she adds.

Similarly, the Yo Sushi chain has also made the exchange, but admits the decision was governed more by cost than ethics. "Bluefin is not used because it is a premium tuna, and therefore very expensive. If we bought bluefin, the higher price would be transferred to our consumer, and we have not raised the price of our sushi for seven years," says spokeswoman Maya Hart.

Elsewhere, high-street retailers such as Marks & Spencer and Tesco have turned to yellowfin tuna because it can be more consistently supplied.

But even yellowfin isn't a particularly environmentally friendly choice. The fish is already graded as four on the Marine Conservation Society's list of fish to avoid, where five represents the most endangered. What's more, Greenpeace estimates that fishing for yellowfin claims the lives of millions of sharks, dolphins, porpoises and turtles, which become caught up in nets and die every year. It's a fact that has led Greenpeace's Sarah Duffy to urge people to consider "whether you want to eat tuna at all".

Change will only really happen, argue environmentalists and restaurateurs, if and when the international community takes action. In the meantime, Caroline Bennett of Moshi Moshi suggests that "even if consumers just make a simple enquiry as to the type of tuna used in their sushi, that is a positive step for change to occur".

Otherwise, sushi fans should try options made with different ingredients such as salmon, crab or mackerel, which are all rated three or below on the Marine Conservation Society's list of fish to avoid. And finally, it might be time to consider the vegetarian versions, made with avocado, cucumber or pepper.