The mysterious disappearance of cod from the North Sea has forced many fishermen to scratch a living from whelks and shrimps instead.
Trawlermen who have spent 30 years searching netting cod are describing the season as the worst in living memory. Some are converting their trawlers into whelking vessels at a cost of up to £30,000 and others seeking jobs on land.
The fish and chip shops of Grimsby and Cleethorpes are buying their cod from trawlers sailing the coasts of Iceland.
Research undertaken by Ministry of Agriculture, Fisheries and Food's (MAFF) Centre for Environment, Fisheries and Aquaculture Science (CEFAS), and published in the journal Nature, has established a link between warm sea-surface temperatures - which are believed to be a result of global warming - and the decline of cod stocks.
While North Sea temperatures have risen in the past 10 years, the harvest has fallen from around 200,000 tons per year to a 1990-1998 average of 100,000 tons.
An apparently freak year in 1996, during which a huge stock of fish was spawned and materialised into a good 1998 harvest when it reached maturity, followed an unusually cold spring. Otherwise, the North Sea has encountered its warmest conditions in the 30 years CEFAS has studied it.
CEFAS believes over-exploitation of cod is another key factor in their disappearance. A high percentage of the fish caught are under four years old which mean few survive to reach sexual maturity. A 40 to 60 per cent reduction in catches is now being recommended.
"We don't know what is going to happen [to temperatures] next year and in the next 10 years," said Dr John Casey, of CEFAS. "But change in temperatures and a stock dominated by young [fish] means that fishery managers must take precautionary measures."
Some fishermen also blame the depleted cod stocks on the amount of seismic activity undertaken in the search for oil and gravel at sea. This also has the potential to disperse fish or alter their behaviour.
The National Federation of Fishermen's Organisations said yesterday that the situation was baffling.
"We've had huge concentrations one year and nothing the next. It's a mystery," a spokesman said.
Harvey Holbrook, a Bridlington trawlerman who spent £30,000 adapting one of his vessels into a whelking craft, said: "I've been on trawlers for 25 years and never seen it so bad. At the moment you can sail for five hours and not see a fish. Now I have just one trawler seeking cod and I'm hoping for a harsh winter next year."
Fred Normandale, a Scarborough trawlerman, said yesterday: "These warmer summers and the amount of seismic activity in the sea are killing the fish and I can't see us going back to cod any time in the coming months."
Some fishermen are scouring the Humber and the Lincolnshire coasts in search of cod - without success, while others are pushing into Scottish and Norwegian waters, where their licences allow.
The EU's decision to cut quotas by 39 per cent to protect fish stocks last year was met by an outcry from many fishing ports in the North-east. Ironically, though, many fishermen now seem unlikely to reach even those reduced levels.