Crumlin - From the food stalls and pie shops of Dickensian London to haute cuisine restaurants in Tokyo, the eel has a long and rich culinary history that transcends classes and national borders.But it is becoming an increasingly rare delicacy as stocks plummet and Europe's fishing industry shrinks to make itself sustainable.With an annual catch of about 600 tons, Europe's largest commercial eel fishery - and the United Kingdom's largest lake - is Lough Neagh in Northern Ireland.Those whose families have fished its shallow grey-green and nutrient rich waters for generations believe their traditional industry and way of life may be coming to an end."There will not be another generation of fishermen. More than half are of pension age. Whenever I finish that will be the end," said Shane O'Neill, a sprightly 70 year old from the nearby town of Crumlin who has worked the lake since 1960.According to legend, Ireland's patron Saint Patrick removed all its snakes, which represented the Devil, and many went into the water and became eels - one possible reason why they are not a popular dish in Ireland.So most of the lake's produce - protected under European law in the same way as champagne and parma ham and a delicacy in countries including Germany, Poland, China and Japan - gets sent abroad.Selling at around $9.7 for 450g or three times the price of other eels, Lough Neagh's catch is also exported across the Irish Sea to Britain.Londoners used to harvest eels from the Thames and they became a staple for the city's working class, whether jellied - chopped and boiled in a stock that cools and sets - or baked in a pie with mashed potato.But most of the capital's eel outlets have long since closed. This week the government, which says the fish is as closely linked to the city as its black cabs, put one that is still doing business, the L Manze Eel, Pie and Mash Shop, under special architectural protection.A dying breedThe decline of London's eel shops mirrors a sharp drop in Europe's stocks.The number of young eels reaching the continent's river systems, where the fish mature before returning to the Sargasso Sea in the Atlantic to breed, has fallen by up to 99% since the 1970s, according to the International Council for Exploration of the Seas group of scientists."It's gone from an extreme abundance to a massive drop of arrivals," said Andrew Kerr, chairperson of the Sustainable Eel Group conservation organisation. "It is a similar level of endangerment to the tiger or panda."There is no single explanation for the drop but possible causes other than overfishing include parasites, damming of rivers, pollution and changes to the course of the Gulf Stream. Scientists say it is very tricky to keep tabs on populations.The EU has plans to maintain numbers, including allowing 40% of adults to escape to the sea, and member countries are limiting fishing, making migration easier and restocking."There's pressure to shut down fisheries. It's a basic conservation measure to stop fishing them," said William O'Connor of the Ireland-based European Eel Consultancy.Around Lough Neagh, eel fishing supports some 300 families and contributes more than $4.8m a year to the local economy, but few young people are interested in working a demanding physical job for little reward.Fishermen work from 03.30 until 18:00 and a boat can bring in 360-400kg a week plus a bonus - but only for the summer season and running costs and taxes have to be paid from that.The co-operative business, founded by a Catholic priest, now has fewer than 60 boats on the lake from more than 200 when O'Neill started fishing. It already has to ship in eels from mainland Britain to maintain numbers.O'Neill believes there will soon be none left casting long lines, with hundreds of baited hooks attached, from the small wooden boats that work the often stormy lake."Most fishermen wouldn't want their sons to carry on fishing and some won't let them," O'Neill said. "They are better off on the dole [unemployment benefit]."