British endurance swimmer Lewis Pugh has completed a swim in the icy waters of the south Atlantic as part of efforts to secure protection for the area’s wildlife-rich seas.

Mr Pugh braved dangerous conditions including water temperatures of just 2C and the presence of huge elephant seals as he swam for 1km (0.6 miles) close to the coast of South Georgia.

Before taking to the water, the campaigner and UN Patron of the Oceans, who has swum in the Arctic and Antarctic and every ocean on Earth, said the “cocktail of cold and wildlife make it for me the most dangerous swim I’ve ever attempted”.

He undertook the swim to urge the Government to protect South Georgia and the South Sandwich Islands, a UK Overseas Territory in the southern Atlantic, which supports wildlife including seals, penguins, sea birds and blue whales.

Mr Pugh is warning that the area is already affected by “very rapid” climate change and industrial fishing fleets seeking new stocks to exploit, having overfished other seas, could soon move in.

He wants the UK to fully protect the area, starting with the creation of a no-take zone around the South Sandwich Islands to prevent fishing, and increased environmental protection around neighbouring South Georgia.

His call to protect the area comes as the Government is being urged to deliver on its pledge to create a “blue belt” of marine protected areas around UK overseas territories, focusing on Ascension Island, St Helena, Tristan da Cunha and the South Sandwich Islands, all in the southern Atlantic.

In taking the plunge – in just his swimwear – in King Edward Cove in South Georgia, Mr Pugh has become the first person to swim in the spot.

Lewis Pugh swimLewis Pugh, who has completed swims in the Arctic and Antarctic, says this is his most dangerous yet (PA)

His 19-minute swim took him past the Grytviken Whaling Station, ending near the grave of explorer Sir Ernest Shackleton.

Mr Pugh has previously used “Speedo diplomacy” to help create the world’s largest marine protected area in the Ross Sea, Antarctica, swimming in icy waters to raise awareness and heading to the US and Russia to help negotiate the final deal.

The latest swim is part of efforts to create a network of marine protected areas around the Antarctic.

Ahead of the swim, he said: “If you were only able to protect half a dozen places on the planet, you would designate the islands of South Georgia and South Sandwich.

“They are one of the most important biodiversity hotspots in the whole world, but only 2% of their waters is fully protected.

“I’m going to do this swim, and draw attention to this amazing place.”