Around 380 pilot whales stranded on the remote west coast of Tasmaniahave died, rescuers said Wednesday.

At least 30 of the stranded whales are still alive, and 50 have already been rescued, Nic Deka, Tasmania Parks and Wildlife Service manager, told reporters on Wednesday.

Around 270 whales became stranded in three locations near Macquarie Harbour on Monday. About a third had died by Monday evening. Many of the whales had become stuck on a sandbar. 

On Wednesday, another 200 beached whales were spotted by air less than 10 kilometers (6 miles) to the south.

"From the air, they didn't look to be in a condition that would warrant rescue,'' Deka said. "Most of them appeared to be dead.''

"We'll continue to work to free as many of the animals as we can,'' he said. "We'll continue working for as long as there are live animals," he added. 

Australia's largest mass-stranding 

Scientists have said the nearly 500 beached whales in Tasmania this week represents the largest mass-stranding ever recorded in Australia.

Australia's previous largest mass stranding event was in 1996 and involved 320 pilot whales off the coast of Western Australia near the town of Dunsborough.

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How were they stranded? 

It is unclear what caused the hundreds of whales to run aground. The pod may have moved close to the coast to feed, or have followed one or two whales on a misadventure, marine biologist Kris Carlyon told a press conference Tuesday.

"It's really likely this was one stranding event of a big group. This would have been one big group offshore,'' he said

wmr/rt (AP. dpa, AFP)