Nearly 500 pilot whales died after getting beached in 2 stranding incidents in New Zealand over the past week

• At least 477 pilot whales got beached on two beaches in New Zealand last week.
• The whales died in two separate strandings on the Chatham Islands on October 7 and October 10.

Close to 500 pilot whales died on the beaches of New Zealand's Chatham Islands after washing up in mass strandings over the last week.

On Friday, a group of roughly 240 pilot whales got stuck on the northwest side of the Chatham Islands, per the New Zealand Department of Conservation. On Monday, another 240 pilot whales were beached at Waihere Bay on the remote Pitt Island, about 25 miles south of the first stranding.

Project Jonah, a local whale rescue organization, confirmed with officials at the conservation department that a total of 477 whales died in the strandings.

"In both stranding events there were some whales that were dead on arrival, with the remaining animals having to be euthanized, to minimize their suffering," the Department of Conservation wrote in a Facebook post on Wednesday. "Despite the events not being uncommon, any loss of life is saddening, especially when they are of this magnitude."

The Chatham Islands have seen bigger stranding incidents before: The conservation department estimated that 1,000 beached whales washed up at the Chatham Islands in 1918.

Dave Lundquist, an advisor at the Department of Conservation, said his department does not try to refloat beached whales because sharks might attack both the rescuers and the whales. As such, euthanizing the beached whales was the "kindest option," Lundquist said.

Lundquist added that the bodies of the dead whales will be left on the shore to decompose naturally.

Project Jonah wrote in a Facebook post on Tuesday that this week's whale strandings are one of the larger beachings the organization has seen.

"Strandings are a complex phenomena, often with multiple factors contributing. It's something that has been happening throughout recorded history and something that scientists are working to understand," the organization wrote on Facebook.

Project Jonah's general manager Daren Grove told CNN that rescuing the whales was very difficult because the beaches are so remote. The Chatham Islands are around 500 miles away from New Zealand's main islands and are home to only 660 people.

In a separate interview with the Associated Press, he called the mass deaths of 477 whales a "heartbreaking" loss.

Grover told the AP that whales might have been disoriented while feeding in the waters off the islands.

"They rely on their echolocation and yet it doesn't tell them that they are running out of water," Grover told the AP. "They come closer and closer to shore and become disoriented. The tide can then drop from below them and before they know it, they're stranded on the beach."

These whale strandings in New Zealand come weeks after a super pod of 200 whales was found beached in a mass-stranding event in Tasmania, Australia in September.