Native oysters are still found off the Essex coast

Pollution, over-fishing, stormy winters and pests were blamed for a decline of oysters since the 1880s.

Nowadays the molluscs, which are rich in Omega 3, are only fished in pockets but could return in cleaner waters.

Government scientists at Weymouth in Dorset, Burnham-on-Crouch in Essex and Lowestoft in Suffolk are supporting the restoration of coastal oyster beds.

Scientists claim that oysters, called "food of the poor", are so high in nutrition and essential oils they accounted for an increase in the average height of 0.4ins (6mm) of Europeans in the early 20th Century.

They are still found off the coast of Essex where an annual oyster festival is held in Colchester.

Important species

Ian Laing, a senior scientist at the government's Centre for Environment, Fisheries & Aquaculture Science (Cefas), said: "Thanks to the Biodiversity Action Plan of Great Britain we are now sure oysters can be successfully reintroduced on a wider scale."

As they only reproduce sporadically, oyster numbers hit rock bottom in the 1980s and scientists feared the species would be unable to regenerate.

Mr Laing said: "The native oyster is still a commercially important species for many fishermen, and after decades of decline we believe there is now a programme in place to protect it.

"The solid return of the native oyster would be a benefit to UK coasts both in terms of economics and biodiversity and we are working to ensure it continues to thrive in the future."

Government fisheries research laboratories have carried out a feasibility study to evaluate all factors involved in restoring the oyster population using species found further afield.