Image copyright Liz Carlson

"It was the worst night of my entire life." That's how Liz Carlson describes finding 145 whales beached and dying on a remote New Zealand beach.

The travel blogger from the US was on a five-day hike on the Rakiura or Stewart Island with a friend when they came across the tragic scene.

What would otherwise have a been a beautiful long stretch of deserted beach was the site of a desperate struggle for life.

Almost 150 pilot whales, beached in the low tide, were fighting in agony in the gentle surf.

Image copyright Liz Carlson

"It was one of these jaw dropping moments," she told the BBC. "We came to the beach around sunset and spotted something in the shallows.

"When we realised it was whales, we dropped everything and ran into the surf."

She'd seen whales in the wild before, she said, but "nothing can prepare you for this, it was just horrific".

'The futility was the worst'

The two immediately tried to find some way to help, to push the whales back into deeper water.

"But you quickly realise that there is nothing you can do. They are just too big.

"The futility was the worst," she said. "They are crying out to each other and are talking and clicking and there's no way to help them."

Image copyright Julian Ripoll

Unable to do anything themselves, they frantically thought of other ways to help.

Stewart Island is very remote, off the coast of New Zealand's South Island, and the beach they were hiking to is even more remote.

The pair hadn't seen any other hikers for the past two days but knew that about 15km (9 miles) away there was a hut where some conservation workers were based.

With no mobile phone reception, they hoped there might be a radio in the hut and Liz's friend, Julian Ripoll, set off running to get help.

'My heart completely broke'

This left her all by herself, amid the scores of dying whales on the vast beach.

"I'll never forget their cries, the way they watched me as I sat with them in the water, how they desperately tried to swim but their weight only dug them deeper into the sands," she wrote on Instagram.

"My heart completely broke."

Image copyright Liz Carlson

The 30-year-old spotted a young baby whale and tried to get it back into the water. While the adult whales were impossible to move at all, she did manage to move the young one.

"It took everything I had to get the baby into the water and then he just kept re-beaching himself," she told the BBC. "After Julian left, I just sat there with the baby.

"You can sense the fear in the animals, they are looking at you. They watch you and they have very human-like eyes."

Image copyright DOC

Over the next few hours, there was little to do other than wait.

"I knew they would inevitably die," Liz wrote on Instagram. "I sank to my knees in the sand screaming in frustration and crying, with the sound of dozens of dying whales behind me, utterly alone."

'Tears in their eyes'

A few hours later, Julian came back with a group of rangers. They were able to assess the situation but at night, it was clear that there was nothing that could be done.

At that time, most of the whales were still in the surf and the tide was still coming in. So Liz and Julian went to their campsite hoping that maybe overnight, the two whale pods would make it back to the ocean themselves.

Image copyright Julian Ripoll

The next morning, they woke to a situation even more dire.

It was low tide and the whales were on the dry sand. Some had already died and the others were lying on the beach in pain, getting baked in the sun.

"They had tears in their eyes," Liz says. "It looked like they are crying and they were making sad sounds."

It was clear that none of the whales could be saved.

Image copyright Julian Ripoll

It takes around five people to move one of the whales and the beach - and the island itself - are so remote that there was no hope of bringing in help in time. Only a few hundred people live on the entire island.

So the rangers had to make what they called the "heart-breaking" decision to euthanise the remaining whales.

The only alternative would have been to leave them to a slow and painful death over several days.

New Zealand's Department of Conservation (DOC) said it would leave the bodies where they are and let nature take its course.

The DOC said it's not clear why whales beach themselves. Solo strandings "are a relatively common occurrence on New Zealand shores" but mass events are rare.

It could be the pod becomes confused by the shallow incline of a beach so goes in too close to shore, or that they are affected by illness

Pilot whales are also highly social, so the DOC says it could be simply that "when one whale loses its way and strands, its pod mates may swim to its aid".

Media playback is unsupported on your device Media caption Almost 150 whales die in mass stranding

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