By Douglas Broom

Endurance swimmer and UN Patron of the Oceans Lewis Pugh has completed a 1 kilometer swim under the East Antarctic ice shelf.

The feat was part of his campaign to secure a series of protected zones in the seas around the continent.

He chose the 200th anniversary of the discovery of Antarctica to make his epic swim.

It's been 200 years since Russian explorer Admiral Bellingshausen discovered Antarctica. It's a frozen wilderness, and the East of the continent is the coldest place on Earth — but scientists say they are starting to see signs of ice loss even there.

Lewis Pugh on Instagram: “Swimming under the Antarctic ice sheet is the most beautiful and terrifying swim I’ve ever done. Every shade of blue, and then nearly…” To draw attention to this plight, endurance swimmer and climate campaigner Lewis Pugh undertook a 1 kilometer swim under one of the region's glaciers. Braving freezing waters and a windchill factor of -15 C, he explored a river running through an ice tunnel formed as a result of the glacier melting. And the experience was eye-opening. "Antarctica is melting," he says. "Everywhere I looked, there was water rushing off the ice sheet, carving long ravines deep into the ice sheet, or pooling into supraglacial lakes." "This place needs protecting," he adds. "It needs protecting because all our futures depend on it."