MARINE sanctuary staff were scratching their heads today over one of the most unusual cases they have ever come across - a seal with a phobia of fish.Five-week-old seal pup Heidi's fear of herrings is the first of its kind for Hunstanton Sea Life Sanctuary, who rescued Heidi from Heacham beach after she was separated from her mother.

MARINE sanctuary staff were scratching their heads today over one of the most unusual cases they have ever come across - a seal with a phobia of fish.

Five-week-old seal pup Heidi's fear of herrings is the first of its kind for Hunstanton Sea Life Sanctuary, who rescued Heidi from Heacham beach after she was separated from her mother.

Herring is the staple diet of all the rescued seals at the seafront centre and Heidi should have been gobbling down whole herring with relish, but the picky pup refused to swallow it for two weeks.

The animal care team at the sanctuary had to resort to blending herring smoothies for Heidi and feeding them to her by tube.

But there are hopeful signs now the orphaned seal has started to investigate fish with her flippers.

Matthew Fuller, an aquarist on the animal care team at the sanctuary, said: 'It's the first time we've come across a herring phobia and it's really quite unusual as all the seals get fed on herring.'

Mr Fuller has his own theory about Heidi, who lost her mother in bad weather and found by the sanctuary on January 21. She was about three weeks old, in good condition and weighed 13kgs.

He said: 'It is probably because it's quite stressful and confusing coming to the sanctuary and she was pining for her mummy. And herring really smells.'

The sanctuary is currently looking after seven seal pups and three resident seals. Once Heidi is at her target weight of 25kgs she will be released back into the wild.

'Her weight is OK now but she will probably be with us in the hospital for another month, and then we will put her in the main pool to learn how to socialise with the other seals,' said Mr Fuller.

'She's quite healthy now and a lovely seal.'

The sanctuary is currently looking after seven seal pups and three resident seals. Once Heidi is at her target weight of 25kgs she will be released back into the wild.

Keiran Copeland, displays supervisor who is also helping to look after Heidi, said: 'We've never encountered a pup more difficult to get food into.

'Hopefully it's just a phase and she'll start taking her meals without a fuss soon.'