A rare blue lobster has been found in the sea off the coast of Sheringham.

CA Seafoods, a fishmongers based in Station Road in the town, caught the crustacean on Sunday (June 26), before putting it back to the sea for conservation reasons.

"It's not very often you see a blue lobster," said a spokesperson for the fishmongers.

The blue colour is caused by a genetic mutation where they have too much of the protein crustacyanin, which makes their outer shell blue.

According to experts from the Lobster Institute at the University of Maine, in the USA, there is a one in two million chance of catching one.

This is an estimate, however, and more have been seen in UK waters recently.

Rob Spray, a diver with the Marine Conservation for Norfolk Action Group (MCNAG), said: "Like us, lobsters vary a lot and if they don't have much brown they will be appear more blue.

"So if there's no brown they'll be very blue, a bit like their version of albino is blue."

Mr Spray said that lobsters are blue because their blood chemistry uses copper - ours use iron - and that gives them their colour.

"The ones most people see are cooked, which changes their blood chemistry and turns them red," he said.

He added: "All lobsters are pretty amazing, they can live longer than us but don't age like we do so treat all of them with respect.

"They live around Britain's longest chalk reef so it's important we protect that for their future."

A similarly blue-coloured lobster was caught in the sea off Jersey in March this year.

The last time this newspaper reported such a catch was in 2009, when one was found at Sheringham, netted by friends Michael Wright, Peter Smith and Barry Moore.

Meanwhile, CA Seafoods has been busy in the community recently, and made a visit to Sheringham High School to give a fish preparation demonstration to year 10 pupils.

The students got to try filleting, butterflying, pinning and even cooked off some of the cuts they did.

A spokesperson from CA Seafood said: β€œIt was a pleasure to visit the school to show pupils who may not have worked with fish before to show them some basics.

"The pupils were very attentive and keen to get stuck in which was great to see.”