It is a prestigious fish that can attract a high price in restaurants, as well as a staple of salads and sandwiches. For many, the versatile and healthy tuna is the king of culinary fish, particularly since the decline of cod. Now, tuna caught in British waters could be on sale in supermarkets for the first time next year.
Fishermen in Cornwall are to launch a study this autumn aimed at proving the theory that there are enough tuna in the waters off the south-west coast to make limited tuna fishing commercially viable.
Cornish tuna would be fresher and rarer than imported tuna – which is mainly from the Mediterranean and the Middle East – and command higher prices.
"One supermarket chain has told me they will buy everything I can land,'' said Robin Turner, a trawler owner and fish merchant in Newlyn, Cornwall's largest fish landing port. "Our aim is to produce a highly desirable, premier product that will demonstrate to people the diversity of fish available from Cornwall.''
Although Cornish tuna is not likely to be as widely available as seasonal foods such as Jersey Royal potatoes or Welsh spring lamb, it would have the same attraction over imported foods. It would also fit in with plans to promote food from Cornwall more strongly and to convince consumers that the county produces more than clotted cream and pasties.
Waitrose sells and advertises Cornish cauliflowers, and chefs including the seafood expert Rick Stein have repeatedly sung the praises of Cornish fish and other produce. Many other common but previously under-appreciated Cornish fish, such as gurnard, are now appearing on restaurant menus in the area. The region's lobsters and crabs are already snapped up by wholesalers for export to Europe or the London hotel market.
Mr Turner has obtained a £40,000 EU grant to pay for the study, which will happen in the autumn, traditionally the peak time for tuna migrating to British waters. The study, by a marine biologist working on Mr Turner's boats, will examine the movement of local fish such as sprats and mackerel, which are food for tuna. In addition, it will monitor the activity of seabirds and whales, which also feed on smaller fish.
If the study suggests a substantial presence of tuna, Mr Turner will seek permission for commercial fishing from the Department of the Environment, Food and Rural Affairs.
Mr Turner says there is evidence of high enough numbers of the fish off Cornwall. Before the Second World War, Spanish and French fishing boats regularly caught tuna in the region. Until relatively recently, big game fishing for tuna was also common. Today, tuna are sometimes landed accidentally by trawlers.
The proposed method for commercial fishing would be trolling – trailing long lines behind boats. The most likely tuna catches would be skipjack, albacore and bonito, which can fetch between £40 and £50 a fish. The mighty bluefin tuna, which is prized by gourmets, particularly for sushi in Japanese restaurants, can fetch £1,000 each, but because it is endangered boats are only permitted to land two per trip.
Establishing even a small tuna fishery would be a lifeline for some Cornish fishermen, who are under severe pressure from EU quotas, mostly on whitefish such as cod and haddock, and who have seen the size of their industry shrink dramatically in recent years. Stocks of pilchard, long ago the main catch, have been devastated by overfishing.
Mr Turner believes the answer to dwindling fish stocks is diversification. "Nobody is talking about tuna providing an income for more than a handful of boats but it is a sign of the way we have to move forward," he said. "There are more than 50 species of fish in these waters and we currently only eat a handful of them."