Volunteers in New Zealand managed to refloat about 100 surviving pilot whales, hoping they will swim back out to sea after more than 400 of them swam aground at a remote beach on Farewell Spit at the tip of the South Island.

A new pod of 240 whales had swum aground at a remote New Zealand beach hours after volunteers refloated a different group following a mass stranding.

In total, more than 650 pilot whales have beached along a 5km (three mile) stretch of coastline over two days on Farewell Spit, at the tip of the South Island. About 335 of the whales are dead, 220 remain stranded and 100 are back at sea.

Volunteers were warned about the possibility of stingrays and sharks, after one of the dead whales appeared to have bite marks consistent with a shark, but worked on regardless.

Whales stranded

Officials will soon need to turn to the grim task of disposing of hundreds of carcasses.

New Zealand has one of the highest rates of whale strandings in the world, and Friday’s event was the nation’s third-biggest in recorded history. The largest was in 1918, when about 1,000 pilot whales came ashore on the Chatham Islands. In 1985, about 450 whales were stranded in Auckland.