The otter population in Norfolk has ballooned to 'crisis proportions' and is stripping private lakes bare, warn fishery owners.

But conservationists claim the animals are attracted by the artificially high concentration of fish which acts as a 'fast food restaurant for otters'.

The animals declined dramatically in East Anglia in the 1960s as harmful agricultural chemicals made their way into the food chain. But a conservation campaign in recent years saw great success and numbers are now back to 1950s levels.

The Otter Trust conservation area was set up in Earsham on the River Waveney in 1971, but has since closed because the population in Norfolk has recovered so well.

This rise has been welcomed by naturalists but those who own fishing lakes in the region have complained otters are eating their way through expensive fish stocks.

John Wilson, the angler and television presenter who owns a lake in Great Witchingham, said: 'A lot of fishery owners have had problems.

'They're slowly munching their way through lakes where people have put a lot of hard work and spent a lot of money to make pleasure spots for anglers. I've had otters invade my lakes and take lots of fish in the last few years. It's got to crisis proportions.'

And he called for a change in their protected status so fishery owners could control them.

John Bailey, director of fisheries and conservation at Kingfisher Lakes and Apartments in Lyng, said: 'There are just too many otters in the county at the moment'.

He claimed that the decline in fish numbers was also having a knock-on effect on birds which feed on them.

David North, education manager at the Norfolk Wildlife Trust, said fishing lakes were like 'fast food joint for otters'.

'You can't really blame the creature when there's an easily available food source,' he said.

And he warned that otters were still a protected species.

'It would be illegal to trap them, shoot them or control them by any means,' he said.

matthew.sparkes@archant.co.uk