BRITISH endurance swimmer Lewis Pugh is to undertake seven swims in the Seven Seas to highlight the need for protected areas in oceans around the world.

He will be the first to undertake a long-distance swim in each of the classical Seven Seas, the Mediterranean, Adriatic, Aegean, Black Sea, Red Sea, Arabian Sea and the North Sea, ending with an 100km (62 miles) swim up the Thames to Parliament.

Mr Pugh, who will complete the seven swims this month, is backing calls by the United Nations for ten per cent of the world's seas - both around countries and on the high seas - to be declared marine protected areas by 2020 to safeguard fish and other wildlife.

Just three per cent of the world's marine areas are protected, compared to around 13 per cent of the world's land area.

Mr Pugh, who has previously undertaken swims at the North Pole and in a glacial lake in Everest to highlight rising global temperatures, said seas were threatened by pollution, overfishing and climate change.

"If we don't do something about it, we're going to be living in a world devoid of wonder and beauty, and frankly not sustainable. If we've achieved it on land, we can do it in the sea."