This GM breakthrough could be the first of many

An American licence to permit the commercial development and sale of genetically modified salmon could open the door on a new era of GM animals designed for human consumption, although at present there are few signs they are wanted by either consumers or supermarkets.

The AquAdvantage salmon is an Atlantic salmon engineered with two extra genes – one from the Pacific Chinook salmon and one from an eel-like species called the ocean pout – which together boost the fish's growth hormones so it puts on weight all year round instead of seasonally.

AquaBounty Technologies of Maynard, Massachusetts, says its GM salmon grows twice as fast as conventional farmed fish.

It can also be reared on land-based fish farms, rather than in sea pens, which according to the company are less polluting as well as having smaller carbon footprints and lower transport costs because they can be sited nearer big cities.

If the US government gives approval to AquaBounty, which now looks increasingly likely, it could change the economics of salmon farming. This could put commercial pressure on producers in Britain and the rest of Europe to follow suit, even though they and their customers have little appetite for GM food.

The Scottish Salmon Producers' Organisation said it opposed the GM fish and envisaged no circumstances where it would become necessary to introduce them. However, this stance could change if other salmon producers can undercut them on costs and efficiency. If the AquAdvantage salmon is officially sanctioned in the US, other GM animals may not be far behind.

Earlier this year, scientists in New Zealand announced they had created a GM cow capable of producing milk which lacks a key protein which can trigger allergic reactions in children.

Scientists have also produced GM pigs which can digest phosphorus in their food more efficiently, cutting food costs as well as lowering levels of harmful pollutants in their manure.

Other researchers have created GM goats which produce milk with a protein that can reduce the risk of diarrhoea in children by improving the bacterial gut flora.

Meanwhile, scientists in Britain are working on GM chickens that are disease resistant.

However, few people see the need for such developments in food technology. The hostility in Britain and the rest of Europe to GM crops such as canola is likely to be dwarfed by the opposition to GM animals, which will be seen as an animal welfare issue as well as an unnecessary risk to human health and the environment.