Around half of the pilot whales stranded on Stewart Island were dead upon discovery; the remaining whales were euthanized due to poor health

One hundred and forty-five whale have died after stranding themselves on Stewart Island in New Zealand.

According to the Associated Press, the two pods of pilot whales were discovered in the remote area, also know as Rakiura, by a hiker on Saturday.

At the time of the discovery, about half of the whales were already dead. Conservationists made the difficult decision to euthanize the remaining marine mammals because of their failing health. The bodies of the whales will be blessed by Ng?i Tahu, the local M?ori tribe, and buried, reports The Guardian.

Ren Leppens, the Rakiura operations manager for the Department of Conservation, told AP that the beached whales were likely stuck on the sand for at least one day before they were found.

“You feel for the animals, it’s just a really sad event,” Leppens said. “It’s the kind of thing you don’t want to see. You wish you could understand the reasoning why the whales strand better, so you could intervene.”

Unfortunately, this isn’t the only mass stranding conservationist are handling: on Sunday, 10 pygmy killer whales beached themselves on another part of the island. Two of the animals have since died, and rescuers are hoping to refloat and save the others.

Incidents of whales stranding themselves are common for Stewart Island and New Zealand as a whole. According to The Guardian, there have been 5,000 recorded stranding incidents in New Zealand since 1840, with an average of 85 incidents each year. Last year saw the country’s largest mass beaching, when more than 400 pilot whales stranded themselves on New Zealand’s Golden Bay. Even with impressive rescue efforts, more than 300 of the whales died.

There is no one answer for why whales end up stranded on shore. Project Jonah, a whale rescue group based out of New Zealand, says it can be because the animals are old, sick, injured or confused.

Project Jonah general manager Daren? Grover told Stuff.co.nz that the set up of Mason Bay, the part of Stewart Island where the 145 pilot whales were found on Saturday, could have been confusing to the whales. The beach’s “gently shelving waters” could have distorted the whales’ echolocation, causing a navigational error for the pods.