EU rules about dealing with fish that are over quota, too small or of the wrong sort).

Why is the CFP such a disaster?
Because the rules are made in a way that seems almost guaranteed to fail. Every year, ministers from around Europe meet and argue over how much fish can be caught. But under pressure to benefit their own fishing communities, they routinely trample over the recommendations of scientists. In 2007 biologists advised an annual catch of 15,000 tonnes of endangered bluefin tuna in the Mediterranean; ministers agreed a quota of 29,000 tonnes. In fact, studies have shown that the politicians systematically set quotas around 25 per cent higher than what scientists recommend.

Do some countries manage things better?
Yes. Iceland has a functioning, sustainable industry thanks to its individual transferable quota (ITQ) system. Each boat is given a quota based on scientific advice and that quota can be traded with other boats. Small or unwanted fish are included in the quota and can't be thrown overboard, so there's an incentive to avoid catching them. New Zealand and Alaska have similar systems. If such strict quotas could be applied to 70 per cent of the world's oceans, say the experts, and fishing be banned in the remaining 30 per cent, there is still some hope of saving the world's fish.

And do fish populations sometimes 'bounce back'?
On occasion. Fish stocks trebled in the North Sea in WWI. A Europe-wide moratorium saved the herring in 1977. But in some seas, the point of extinction may have passed. The collapse of cod in the Newfoundland Grand Banks, waters that once ran thick with them, is an example. To arrest the decline, cod fishing has been banned there since 1992, but there has been no recovery. In response, consumers are switching from cod to pollack, but as Clover points out, this just moves the problem down the oceanic chain to the next species. The fish now sold in supermarkets are of quite different species than those sold 15 years ago. More than 50 per cent of fish bought in British supermarkets are now farmed, a percentage likely to grow ever higher as wild stocks disappear.

So will there be anything left in the sea for us to eat?
Jellyfish. Scientists have found that, due to overfishing, the weight of jellyfish in the Benguela current off Namibia - once one of the world's most prolific fishing areas - now far exceeds that of its commercial fish stocks. Much the same has happened in the Black Sea, where plentiful fish stocks were over-fished and then overwhelmed by an Atlantic jellyfish species. Jellyfish compete for much the same food resources as the fish they displace, so preventing their recovery. Off the coast of Japan, vast armadas of slimy, six-foot Nomura jellyfish have been poisoning the native fish with their tentacles - local fish catches have fallen as much as 80 per cent as a result. But in one fishing town, enterprising locals now run cookery classes to teach people how to turn the jellyfish into sushi and other snacks. If we fail to conserve world fish stocks, jellyfishfingers could well be the food of the future.