Just three days after 145 pilot whales died following a mass stranding on a remote stretch of sand on Stewart Island, New Zealand, the Australian Associated Press reported that a humpback whale and 27 pilot whales beached on the shores of Croajingolong national park in Victoria, Australia, on Tuesday. As of yesterday afternoon, the majority of the marine mammals had already perished.

“We have flown in experienced staff including a wildlife expert by helicopter to conduct an initial assessment late this afternoon and they have found that unfortunately most of the whales have died, with the few remaining not expected to survive,” Michael Turner, an employee of the Victoria environment department, told the news outlet. Indeed, the animals died shortly after.

And in the third such tragic incident in one week, a pod of pygmy killer whales beached on New Zealand’s Ninety Mile Beach on Sunday. Currently, only one of the animals is still alive.

According to the New York Post, by the time Department of Conservation staff arrived at the beach – located near the tip of the nation’s North Island – two of the cetaceans were already too far gone for rescue attempts and died soon after. Meanwhile, officials and volunteers from the cetacean non-profit Project Jonah tried to keep the other eight animals alive, while a refloating plan was being formulated, by draping them with wet cloths and continually drenching them with seawater.

The next day, the remaining pygmy killer whales – which are actually a rare type of dolphin that marine scientists know little about – were transported across the peninsula by road on hay-lined trailers to Rarawa Beach, where the waters are calmer. When they arrived, the dolphins were once again kept cool and damp until the next high tide the following morning. Over 200 volunteers came to Rarawa to help refloat the mammals on Tuesday.

Sadly, two dolphins quickly re-stranded themselves, as often happens during these mysterious occurrences.

“They were calling to the other whales in the pod and they were coming back in,” Department of Conservation ranger Jamie Werner told the Post. “So we made a quick decision to euthanize them.

“It’s actually phenomenal to see how in tune they are with each other.”

Werner and his colleagues then stayed on the scene to monitor the six animals until they swam into deeper water. But by Wednesday, five of the six dolphins left alive had also re-stranded, per Newshub, forcing agency veterinarians to put them down as well.

The one remaining whale is believed to still be offshore. 

"I can confirm that the remaining pygmy killer whale has not been seen since Wednesday afternoon," Project Jonah general manager Daren Grover told IFLScience. 

"Regarding strandings, New Zealand has one of the highest stranding rates in the world but thanks to our organisation and well-trained members of the public, we also have one of the highest success rates," he continued. "Whales and dolphins can strand for many reasons, whether they may be old or sick, or in unfamiliar waters and caught our by some of our geography (gentle sloping beaches with a large tidal range that can catch out whales close to shore)."

"They might also be chased close to shore by other ocean predators or confused by underwater sounds including those made by humans. There are other human-caused (anthropogenic) reasons including; eating plastics in the ocean and becoming emaciated, increased pressures on food caused by over-fishing, increased ocean temperatures caused by climate change, and being caught and injured in fishing nets."