Nearly 400 whales are dead in mass stranding off coast of Australia

Nearly 400 pilot whales have died after they became stranded off the coast of Australia, wildlife officials announced Wednesday.

The whales began piling up off Macquarie Harbour on Tasmania's West Coast earlier this week, according to the Tasmania Parks and Wildlife Service. While marine biologists initially believed about 270 whales had been stranded in three different locations, a fourth location containing an additional 200 whales was found about 6 miles into the harbor at Fraser Flats.

Practically all of those whales were found dead. About 30 at that location remain alive, marine biologists determined.

Nearly 380 whales in total have died.

On Wednesday, rescue crews continued their attempt to save the whales by re-floating them, according to the wildlife service. So far, about 50 have been saved.

"That’s a success and we will continue to try and free as many of the remaining alive animals as we can," said Nic Deka, wildlife regional manager for the Tasmania Parks and Wildlife Service.

Many of the whales are in locations that are not easily accessible, Deka said. But the wet and cool weather -- as well as a higher tide in coming days -- is increasing the likelihood that some of the whales will survive, he noted.

"Whenever they are still alive and still in water there is certainly hope for them, but as time goes on, they do become more fatigued and their chance of survival reduces," Deka said. "We will continue working while there are still alive animals on site."

Strandings of pilot and sperm whales are not uncommon in Tasmania, Deka said on Monday, adding that Macquarie Harbor seems to be a "hot spot."

The location where the 200 whales were found dead was a farther distance than the other spots and "not necessarily a place that is obvious for a stranding," Deka told reporters on Wednesday.

The whales' navigation and false echoes may lure them into the harbor and wildlife biologist Dr. Kris Carlyon hypothesized that the "misadventure" of one or two whales while feeding off the coast could lead many others astray because of the social nature of the species.

“There is little we can do to prevent this occurring in the future," Carlyon said Wednesday.

Rescue crews will do a more extensive search now that more whales have been found, Deka said. Pilot whales often travel in pods of up to 1,000, so there may be more offshore, Carylon said.

ABC News' Tomek Rolski and Christine Theodorou contributed to this report.