Hundreds of dead whales that washed up on a New Zealand beach will be left to decompose naturally on land.
Over the past week, two mass pilot whale strandings have occurred on two different areas in the Chatham Islands, an incredibly remote area off the eastern coast of New Zealand's South Island.
According to marine mammal rescue organization Project Jonah, 232 pilot whales stranded on Chatham island on October 7. On October 10, a further 245 whales were stranded on Pitt Island. This brings the total number of stranded whales to 477.
The Chatham Islands is a whale stranding hotspot, but the reason why remains a mystery to scientists.
Project Jonah said on a Facebook post that this was "one of the larger events for mass strandings in New Zealand."
While many pilot whales were already dead when rescuers arrived, some were still alive. But due to the remoteness of the area, rescue efforts remain incredibly difficult.
Re-floating whales is a challenge in itself—often they will become disoriented and beach themselves again and again. In these cases, the surviving whales were sadly euthanized.
The remoteness of the location does not just make rescue efforts difficult—it also means it is difficult to bury and remove the whale carcasses.
Project Jonah general manager Daren Grover, told the Washington Post that "nature is a great recycler," meaning leaving the bodies to decompose is the easiest option.
"All the energy stored within the bodies of all the whales will be returned to nature quite quickly," Grover said.
Culum Brown, professor at the School of Natural Sciences at Macquarie University told Newsweek that the decomposition process of this many whales will "definitely attract sharks and other scavengers to the area."
Great white sharks are known for surrounding this particular area—another factor making rescue efforts difficult.
"They will stick around for quite some time. Of course sea birds and perhaps even terrestrial animals will also have a go at the carcasses. It's going to be an absolute bonanza for invertebrates (worms, snails, crabs etc)," Brown said.
"Most of the decomposition will occur within weeks, but it may take up to a year or more for the animals to be stripped back to the bones. One thing is for sure, it will stink like nothing else!"
"In this case it's a pretty remote location and they simply haven't got the capacity to do much about it from a practical perspective. Also, the fact that there are so few people about means that no one will likely complain about the smell. So leaving them in place is the easiest option," he said.
While the overall cause remains a mystery, there could be several factors at play, including sickness and disorientation.
Scientists believe pilot whales' complex social bonds play a big part in why this species strands so often.
"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," Project Jonah said in a Facebook post.
"We do know that the tight social bonds of pilot whale pod in particular are one of the reasons why such large numbers of these animals stranding together."
Uncommon Knowledge
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
Newsweek is committed to challenging conventional wisdom and finding connections in the search for common ground.
About the writer
Robyn White is a Newsweek Nature Reporter based in London, UK. Her focus is reporting on wildlife, science and the ... Read more
