WELLINGTON: Volunteers in New Zealand were trying to save 40 stranded whales Monday evening by refloating them on the high tide.
Nine more whales had already died.
The pod of 49 long-finned pilot whales beached themselves on Farewell Spit, a remote beach on the South Island, the Department of Conservation reported.
The whales were first noticed by a tour operator on Monday morning, the department said.
About 65 conservation rangers and volunteers worked throughout the day to help the whales by keeping them cool and wet until the water was deep enough to refloat them.
The nonprofit whale rescue group Project Jonah was helping coordinate efforts.
Farewell Spit, a sliver of sand that arches like a hook into the Tasman Sea, has been the site of previous mass strandings.
Sometimes described as a whale trap, the spit's long coastline and gently sloping beaches seem to make it difficult for whales to navigate away from once they get close.
There are different theories as to why whales strand themselves, from chasing prey too far inshore to trying to protect a sick member of the group or escaping a predator.
Four years ago, more than 650 pilot whales beached themselves on Farewell Spit in two separate mass strandings.
More than 350 of the creatures died while about 300 were saved.
Pilot whales are relatively small but can grow to over 6 meters (20 feet).