RARE loggerhead turtles spotted near Swanage are at risk of stranding on beaches as the sea temperature drops.

The Marine Conservation Society is urging people out walking to be vigilant and look out for the endangered creatures, which they say will struggle to survive in cooling UK sea temperatures.

The UK’s leading marine charity was contacted by Sarah Fargher from Fuzzacker Guided Walks, based in the New Forest, after the group of walkers she was with spotted the turtles while walking along the coast path at Durlston Head.

“When one of our group said 'it looks like a turtle', I resorted to some pretty unsubtle persuasion in order to borrow the highest strength binoculars on the cliff," she said.

"As it swam towards us its ochre skin and brown shell became unmistakable; I was so excited when I realised it must be a loggerhead. I just hope it makes its way back to warmer waters,” said Sarah.

The group were amazed to see a second turtle at the same time. Sarah estimated the turtles to be about 50 metres from the shore, and says it could have been between two and three feet in length.

MCS head of biodiversity and fisheries, Dr Peter Richardson, says that of the seven species of marine turtle, loggerheads breed at the most northerly latitudes, with the nearest breeding populations to the UK found in the Mediterranean, the Cape Verde Islands and the south eastern USA.

“This is a fantastic record because live loggerhead turtles are rarely spotted in UK seas, but to see two together is incredibly lucky,” said Dr Richardson.

A Weymouth sailor spotted one in the waters off Portland Bill in August 2013.

Juvenile loggerheads spend their first few years swimming at the surface of the open ocean feeding on jellyfish and other creatures at the surface, before settling in inshore waters where they use their powerful beaks to eat crabs and other shellfish.

“South west inshore surface temperatures waters are about 15C at the moment. As the seas cool down these turtles will stop feeding, lose condition and suffer from acute hypothermia. If they are lucky, they may strand alive on a beach, and if found in time they can be rescued and rehabilitated back to health with specialist treatment," said Dr Richardson.

He said they should not be put back in the sea as they will certainly die. Anyone who sees a stranded turtle is urged to report it immediately to Marine Environmental Monitoring on 01239 683033.