About 140 pilot whales that stranded themselves on a remote stretch of New Zealand beach have died.

But conservation workers and volunteers are hoping the remaining 60 or so stranded whales will survive after they managed to get them refloated Saturday night.

The geography of Farewell Spit on the South Island seems to work against whales, which regularly become stranded there. The stranding of 198 whales on Friday was one of the largest in recent years and prompted 80 workers and volunteers to help out.

Department of Conservation area manager Andrew Lamason said the stranding has been very sad because whales are such intelligent animals.

Pilot whales grow to about 6 meters (20 feet) in length.