CHRIS BISHOP A freshwater cod which had its chips more than 30 years ago could be re-introduced to our rivers. The last burbot was caught in the Ouse at Denver Sluice, near Downham Market, in 1970.

CHRIS BISHOP

A freshwater cod which had its chips more than 30 years ago could be re-introduced to our rivers.

The last burbot was caught in the Ouse at Denver Sluice, near Downham Market, in 1970.

Since then the mysterious fish, which can grow to up to 30lbs, is believed to have become extinct.

Now scientists at Brooksby Melton College, in Leicestershire, have brought back 40 specimens caught by trappers on a river in Denmark.

And by creating conditions which mimic those found in Britain's rivers, they have encouraged the fish to breed.

More than 200 fry were successfully hatched and it is hoped that their descendants might one day be released into the Great Ouse system, to re-colonise the river catchment.

Fisheries scientist Ian Wellby, who is leading the project, said: “It's a feasibility study, to see if reintroduction is feasible. We need to breed fish first, to see if their eggs can survive.

“We need to prove that whatever caused them to go extinct is no longer relevant. Part of the project is to investigate why they became extinct, one theory is that rivers became warmer during that period.”

Burbot, which resemble a cross between an eel and a cod, were once common throughout East Anglia. They are now confined to eastern Europe and Scandinavia.

Scientists call them by their latin name, lota lota. Fen fisherfolk knew them as pout eel, while around the Theford area, they were known as coney fish, as they were believed to spend much of their time hiding in holes in the bank.

“It is olive green, marbled boldly with black and a conspicuous feature is the long, pointed, beard-like tag which hangs down beneath its chin,” the EDP's renowned nature columnist Ted Ellis wrote in 1958.

Burbot prefer deep, fast-flowing rivers. As well as the Ouse and its tributaries the Lark, Little Ouse and Cam, they once inhabited the Yare and Waveney, and the Trent.

Their eggs float and one theory is that oil deposits washed off roads into rivers, as car ownership became the norm in the 1950s and 60s, were what killed them off.

But while burbot were originally a river fish, legislation effectively now means they can only be re-introduced to lakes.

“The reintroduction of burbot in England would require a licence under the Import of Live Fish Act from Defra,” an EA spokesman said, adding: “We suggest that Mr Wellby discusses licensing for burbot with Defra.”