Half of seafood may be farmed by 2025

The agency estimates that at some point between 2015 and 2025, half of all fish consumed in the world will be farmed.

New molecular and biotechnology tools will be required to bring fish farming on a par with farming of other livestock, says Professor Zohar.

Whereas people have improved the genetics, health, nutrition and reproduction of other livestock through centuries of husbandry and science, time may be far shorter for improving seafood crops, he told the International Marine Biotechnology Conference in Queensland, Australia.

'Unproven science'

But environmental campaign group World Wide Fund for Nature, WWF, says GM fish are a distraction from the pressing issues that face our oceans today.

"GM fish may offer a solution to fish as a food resource, though the science is far from certain on this matter, but it will not address the unsustainable and catastrophic exploitation of our seas and oceans," said a spokesperson.

WWF says it is working on solutions that, in 20 years' time, will see wild fish stocks rising, bringing benefits to communities dependent on the marine environment.

"Now everyone can see the problems facing our seas it's a question of getting the political will to enact legislation providing the protection they need to ensure the recovery and improvement of fisheries," the spokesperson added.

GM salmon

The first genetically modified fish, salmon that grow up to 10 times faster than normal, could be cleared for human consumption within a year.

A US firm - AF Protein - is developing the GM fish on Prince Edward Island, Canada.

The Massachusetts-based company has inserted two sets of fish genes into Atlantic salmon.

The first are growth hormone genes and the second, from a different fish, activate them.