UK scientists to turn fish vegetarian

Farmed salmon, trout, haddock and cod are fed on smaller, wild fish.

And as they can consume up to five times their own weight, the industry is rapidly becoming unsustainable.

But now government scientists at the Centre for Environment, Fisheries and Agriculture Science in Lowestoft believe they have discovered a chemical to make farmed fish eat vegetable matter.

Dr Andy Moore told BBC News: "This will revolutionise fish farming worldwide."

Dr Moore and his colleagues have developed a synthetic version of the pheromone released by fish that makes them hungry.

And tests show fish start snapping at the water, looking for anything to eat, once they sense its presence.

Litmus test

The scientists say that since a certain amount of the pheromone is naturally produced in the water by the fish anyway, it is unlikely to adversely affect their health.

But although the industry has welcomed the discovery, concerns remain that consumers may be put off by what they will see as the unnatural altering of fish behaviour.

Don Staniford, of Friends of the Earth, told BBC News: "The fish may swallow the idea - but will consumers?

"That is really the litmus test at the end of the day.

"Will the public buy the end product?"