A rare white harbour porpoise has been spotted off the coast of Morwenstow – only the sixth ever recorded in the UK and the first in England.

The animal was photographed by Henry Kirkwood on November 28 and marine conservation research charity Sea Watch Foundation is encouraging people to report any further sightings.

Sightings officer Kathy James said harbour porpoises are usually a brown to grey colour with lighter underparts.

“Henry’s photograph shows the typical view that an observer usually has of a harbour porpoise, with a broad-based, triangular dorsal fin showing in the centre of its back,” she said.

Another view of the porpoise, showing some darker colouration around its blowhole. Picture: Henry Kirkwood Another view of the porpoise, showing some darker colouration around its blowhole. Picture: Henry Kirkwood

“However, the big difference is that they are not usually white.”

Kathy said that many people might be tempted to refer to the porpoise as an albino, but the animal’s appearance was probably due to a phenomenon called leucism, whereby only some of the cells lose the ability to produce melanin.

Albinism is caused by a genetic mutation resulting in the animal being unable to produce melanin, the pigment which gives rise to colour.

Photographer Henry, from Derriton near Holsworthy, said he had spent much of the day photographing peregrine falcons from the cliff tops with his father Rupert.

It’s not often that one gets to glimpse the whole head of a harbour porpoise. Picture: Mick Baines/Sea Watch Foundation It’s not often that one gets to glimpse the whole head of a harbour porpoise. Picture: Mick Baines/Sea Watch Foundation

He said they saw several seals and a couple of conventionally-coloured harbour porpoises before spotting ‘a small white glint’ in the sea.

“Initially I thought that this might be the fin of a very pale Risso’s dolphin, but on closer inspection through binoculars I was amazed to see what looked like a completely white porpoise,” said Henry.

“The porpoise was completely white, apart maybe from some darker pigment around the blow hole. I had no idea quite how unusual this observation was, until I arrived home and trawled through the internet to learn that there has been only a handful of such sightings reported, and hardly any photographs.

“I went back the next day to try and get some better images knowing that porpoises tend to be quite sedentary, but with no luck.”

The more typical colour of a harbour porpoise. Picture: Mick Baines/Sea Watch Foundation The more typical colour of a harbour porpoise. Picture: Mick Baines/Sea Watch Foundation

People are urged to keep an eye out for the distinctive animal and to report any further sightings at www.seawatchfoundation.org.uk/sightingsform