Cod and chips, please (but hold the cod: they've had their chips)

The terrible truth has finally dawned on Christopher Hirst, our man in the chippy. The fate of cod is not just a tragedy for the environment, it's a disaster for the great British stomach

It's as much a part of British life as warm beer and rain in July. But this summer, in Britain's fish and chip shops, non-brewed condiment is being shaken with tremulous hands. The reason for this unwonted nervousness among fans of the fishy fry-up is that news is sinking in that their favourite dish has been declared an "endangered species" by the World Wildlife Fund. Genial souls who have happily spent their entire lives innocently raising batter-encrusted chunks of Gadus morhua to their salivating jaws are suddenly burdened with qualms. Can it really be that cod is endangered, like the panda or the rhino? And, if so, does that turn a trip to the chippy into the moral equivalent of a tiger hunt?

It's as much a part of British life as warm beer and rain in July. But this summer, in Britain's fish and chip shops, non-brewed condiment is being shaken with tremulous hands. The reason for this unwonted nervousness among fans of the fishy fry-up is that news is sinking in that their favourite dish has been declared an "endangered species" by the World Wildlife Fund. Genial souls who have happily spent their entire lives innocently raising batter-encrusted chunks of Gadus morhua to their salivating jaws are suddenly burdened with qualms. Can it really be that cod is endangered, like the panda or the rhino? And, if so, does that turn a trip to the chippy into the moral equivalent of a tiger hunt?

Maybe it's quite not that bad, yet - and there are many who criticise the WWF's announcement as misleading: how, they ask, can a takeaway be called an "endangered species"? - but the writing has been on the wall for years. We tend to forget that the homely cod is in fact a wild animal. Fishing is hunting with nets. If we over-hunt a non-renewable resource, it will not magically return. In his supremely authoritative Oxford Companion to Food, Alan Davidson notes that an Atlantic cod was once recorded as reaching a weight of over 200lb and a length of 6ft. For anyone planning to lay down a jeroboam of Sarson's in order to anoint such a monster, Davidson adds his own dampener: "This seems almost incredible nowadays when the maximum weight is in the region of 25lbs and an average market specimen weighs only 10lbs."

The danger of what will certainly happen unless we control over-fishing was made plain in Mark Kurlansky's acclaimed 1997 book, Cod: A Biography of the Fish That Changed the World (how many other animal species have acquired a biography?), which opens with a gloomy account of the Newfoundland Banks. For almost 500 years, this cod-fishing ground was one of the world's greatest protein resources. Since 1992, however, it has been closed. Kurlansky reports on a rare fishing foray permitted for research purposes: "The catch [on one boat] was a disaster... Only 40 fish have been tagged. The biggest is just 30 inches. Ten years ago, this record fish would have been barely the average size." A hundred fish caught by another boat weighed a total of 375lb. According to the WWF, the same sparsity will soon be found on this side of the Atlantic.

It is no little irony that this threat to cod has arisen just as the fish has become poisson de choix on the menus of the UK's ritzier nosheries. Chef-patron Gordon Ramsay is a big fan, and not just because he speaks like a fishwife. "It is the lovely convex flakes of cod that are perfect," he writes admiringly in his book, Passion for Seafood, while warning: "Certainly the larger fish that once yielded chunky steaks are an increasing rarity." In Taste of the Sea, his fellow ichthyophile Rick Stein notes: "It is a source of great satisfaction to me that we can now sell cod at the restaurant as easily as bass or salmon." However, such elaborate concoctions as Ramsay's Fennel Soup with Pan-Roasted Cod or Stein's Roast Cod with Aioli and Butter Beans are not the items that spring to mind when British people think of cod.

Neither do we think of cod as it appears fresh from the trawler, a slack-jowled, rather shapeless bottom-dweller. (Its etymology adds little to the romance of the fish - in Middle English, the word "cod" meant "bag".) Instead, the image which invariably occurs is of a fat, batter-shrouded wedge, fresh trawled from a seething vat of bubbling fat. We have been chomping the magical combination of fish and chips since at least the 1860s, though, according to the droll Davidson, the two component parts existed separately for more than half a century before. "It would be a rash historian who would deny the possibility that they had joined forces, somewhere, somewhat sooner."

The number of fish and chip shops continued to swell until the Second World War, and they are still a feature of almost every UK high street. Even the lah-di-dah resort of Frinton has one (a pretty good one at that). Most chippies are family-owned, which is why (with the exception of Harry Ramsden's) there are no large-scale fish-and- chip-shop chains in this country.

Not everyone likes the combination of fish and chips. In one of his restaurant reviews, the writer Craig Brown likened the experience to "eating socks". But this lack of relish is rare. Most of us succumb on an occasional or regular basis - and once you've got the urge, it is impossible to resist. I have rarely endured salivary torture comparable with that of standing in the particulate-rich atmosphere of a fish-and- chip-shop queue. Having acquired your fresh-wrapped package, it should preferably be consumed in an extra-mural banquet - and with fingers, not those prissy plastic forks. What could be more reliable than this perfect gastronomic marriage?

Well, lots of things, to be honest. Whenever I've had fish and chips in London, I've been disappointed. The fish is rarely fresh enough and when it is, the batter is usually not cooked properly, containing a subcutaneous layer of uncooked batter below the crispy crust.

One place where fish and chips are trustworthy - indeed, obligatory if you happen to be there - is on England's east coast. I have had stupendous fish and chips at Aldeburgh in Suffolk and Whitby in North Yorkshire, and at many spots in between. But you have to pick and choose. A queue is usually a good sign, but popularity does not guarantee excellence. Despite a packed car park, the HQ of Harry Ramsden's, a vast roadhouse at Guiseley outside Bradford, served fish and chips that were tired and flaccid on my last visit. Its chandeliers of Bohemian cut-glass were scant recompense.

Usually, the fried fish on the Yorkshire coast is pretty good. Just occasionally, it can be out of this world. I remember sitting in my car on a ghastly, rain-lashed afternoon and opening the package (it was almost too hot to rest on my knee) that I had just acquired from one of Filey's prodigious number of chippies. The fish was so fresh that there was a thin cream between each of the flakes and the batter was wonderfully crisp and tempura-light. Despite the rain, my head was filled with sunshine. Not that the purchase of fish is de rigueur in Yorkshire fish and chip shops. While waiting in the same establishment (despite returning several times, I've never enjoyed quite the same transcendental excellence), I recently watched eight people being served. Of these, no fewer than six had exactly the same thing: chips and bits (or "scraps", as morsels of batter detritus are called in this part of Yorkshire) covered in a thick slurry of curry sauce. Depressing, but I suppose it's good for the cod stocks.

One reason that fish and chips are so good up there is that the frying medium is almost always dripping (rendered beef-fat). I don't suppose it's advocated by many nutritionists, but dripping imparts a richness of flavour unknown in southern chippies. Cooking potatoes in animal fat may sound bizarre, but in his pioneering volume, The Man Who Ate Everything, American food critic Jeffrey Steingarten notes that Alain Passard, whose Paris restaurant L'Arpege has three Michelin stars, "cooks his French fries only in horse fat". (Steingarten's attempt to reproduce these Elysian frites in his New York kitchen failed when the Austrian horse fat he imported went rancid in transit.)

The second reason why fish-and-chip addicts should make tracks for Yorkshire is that, in general, we tykes do not eat cod. Gordon Ramsay may fulminate and Rick Stein may politely demur, but cod is customarily scoffed at as "watery" in Yorkshire. We plump for the more aristocratic haddock. We are not alone in this view. As Davidson notes in his incomparable book North Atlantic Seafood: "The haddock is held by many, including the knowledgeable Icelander, to be superior to the cod."

However, this does not mean that haddock-fanciers can breezily ignore the WWF's warning. The haddock is a member of the cod family and subject to the same deprivations. For some of us, the loss of cod and haddock would have a greater impact than the beef crisis. But there would be this difference: once these astonishingly generous fish have gone, then they've gone for good. The WWF may be overstating its case, but the organisation is absolutely spot-on in its insistence that we must stop the wholesale plunder of Atlantic cod. Otherwise, we'll all have to develop a taste for chips and bits in curry sauce.