The process began last month, with scientific advice on the state of the stocks from a body called the International Council for the Exploration of the Seas (ICES). As usual the advice was gloomy, pointing out that several of the most commercially important species such as cod are at a dangerously low level.
The process will end in a long, frantic night of horse-trading in Brussels in just over a fortnight, when EU fisheries ministers sort out the final quotas. Based on past experience, they will bow to pressure from their fishing industries and allocate larger catches to their fleets than the scientists say is prudent.
And so, for another year, across the broad and shallow waters of Western Europe's continental shelf, fishermen risk a dramatic collapse in a species such as cod to the point where it no longer turns up in their nets. That would ruin tens of thousands of livelihoods, thousands of them in Britain.
The industry receives this warning each year. It is getting louder, because environmental groups now consider over- fishing in the North Sea a serious issue.
The fishermen know that they catch and kill many more fish than their quotas allow. Huge quantities are thrown back into the sea, dead, because they are illegally small or the wrong kind; having caught their quota of one species, the fishermen go for another, but find the first species in their nets.
Apart from discards, there is a substantial but completely unknown quantity of ``black fish'' - species which are over-quota or for which boats have no licence, which are landed in the dead of night at ports around Europe, some in Britain.
The industry also knows stock collapses are a reality. It happened to North Sea herring and mackerel in the 1970s, and by 1978 an annual herring catch which had stood at more than 700,000 tons eight years earlier had fallen to nothing. Herring stocks recovered in the North Sea; mackerel has not.
Yet the fishermen know their prey are still out there in large numbers, and question the scientists' advice. Some believe the experts exaggerate the threat, knowing that bargaining over the quotas will inevitably reduce the cuts they suggest.
The cod is generally thought to be most at risk. It does not reach sexual maturity until the age of four, but the great majority in the North Sea and Western Approaches are caught before then. The national fisheries scientists gathered under ICES say the number of mature cod - the adults which must breed to produce future generations - is just over half the "minimum biological acceptable level" - below which the risk of stock collapse starts to escalate.
``The stock is considered to be outside safe biological limits,'' says the ICES report. It recommends a 20 per cent cut in catches, which it judges would have a 95 per cent chance of bringing cod stocks back to a healthy level within a few years.
It points out that such a cut is unlikely to be achieved simply by reducing the cod quota, because large numbers of the threatened fish are caught by trawlermen pursuing ``mixed roundfish'' - mainly a mixture of haddock and whiting.
Stocks of North Sea haddock are also judged to be below the "minimum biological acceptable level", and so are several other species. They include the North Sea herring, which is once again in danger, having recovered from its spectacular collapse in the 1970s.
Ideally, what is needed for all these threatened stocks is a serious, sustained laying-off of fishing. That would allow the number of breeding adults to recover to a level where more fish could probably be caught each year than are taken now. EU governments seem highly unlikely to come up with the massive sums in compensation which fishermen would demand in return. And so the danger and the depletion continue.
Like his colleagues from other nations, the UK fisheries minister, Tony Baldry, is under pressure to reject any big quota cuts. ``The Government will be particularly concerned whenever possible to avoid excessive year- on-year changes in quotas in order to avoid unnecessary dislocation in the fishing industry,'' he said. But a collapse, if it comes, would be the ultimate dislocation for fish and man alike.
The endangered species
HADDOCK: A close relative of the cod and just as popular, battered up and wrapped in newspaper, in the nation's chippies. It, too, lives on the seabed where it eats crabs and invertebrates. Smaller than cod, it reaches sexual maturity at three years old. It can grow to up to 70 cm but rarely escapes trawler nets for long enough to do so.
PLAICE: Not the priciest of the flatfish, but the most abundant and commercially important. North Sea stocks have been declining through over-fishing, and are judged by scientists to be in danger of collapse - about 40 per cent are killed by fishing each year. The fish reaches sexual maturity at about three years, and in 15 years can grow to 75cm.
HERRING: A pelagic fish, swimming well above the sea bed and eating plankton. Grows to about 40cm in 10 years. Beloved by the British as kippers, hundreds of thousands of tonnes are caught each year in the North Sea to be made into oils and animal feeds. Stock collapsed spectacularly in the 1970s, and is in danger of doing so again.
MACKEREL: Another oily, pelagic fish which grows slightly larger than the herring. Huge quantities are caught for in an "industrial fishery" and processed in factories for oil and animal feed. Stocks in the North Sea collapsed in the 1970s and never recovered, but the quantities taken from waters further out to the west are rising.Reuse content