A pygmy blue whale more than 21 metres long has washed ashore at Carters Beach near Westport, drawing a steady stream of locals down to the sand and handing scientists a rare chance to study an animal New Zealanders almost never see up close.
The Department of Conservation said the whale was spotted floating in the surf on Monday and came ashore on Tuesday, a little over two kilometres down the beach south of the township. It measured 21.7 metres and DOC believes it weighed about 20 tonnes.
DOC’s acting operations manager for the Buller District, Kushla Tapper, said the whale had died recently and the cause of death was not known. Tissue samples have been taken for future research.
“A lot of locals have come down to see this beautiful creature. It’s unusual and impressive to have a whale of this size on the beach,” Tapper told RNZ.
Contractors with diggers were brought in to bury the body in the sand near the dunes. DOC staff spoke with local iwi, the tribal groups who hold authority over that part of the coast, about what should happen to the animal.
Tapper asked anyone visiting the site to keep well back, for practical reasons as much as legal ones.
“As well as being very hard to remove the oily smell from any contact with the whale or surrounding beach sand, it is an offence under the Marine Mammals Protection Act 1978 to interfere with any whale – dead or alive – without authority,” she said.
Westport resident Trace, who supplied photographs of the whale, drove out to the beach on Tuesday afternoon after hearing what had happened. She said the scale of the animal was hard to take in.
“Driving towards it was surreal because it just got bigger and bigger the closer you got to it, to be honest,” she told RNZ.
“The mouth was completely open and there was this mass and apparently it was the tongue and it was just absolutely huge.”
She said there was a trail of blood running from the front of the whale out to sea, and the smell at the tail end was overpowering. “Children were gagging from the smell, it was quite pungent,” she said. Plenty of people were fascinated by the sight, she said, but there was sadness in it too.
Strandings themselves are not unusual in New Zealand. DOC responds to an average of 85 stranding incidents a year, usually involving single animals, and more than 5,000 strandings of whales and dolphins have been recorded around the coast since 1840. Blue whales are almost never among them. Te Papa suggests part of the reason is that blue whales are solitary rather than social animals, so they do not come ashore in the groups that pilot whales are known for.
There are two blue whale subspecies in the southern hemisphere, the Antarctic blue whale and the slightly smaller pygmy blue whale. Even the smaller one is enormous. DOC puts the average length of mature southern hemisphere blue whales at about 25 metres for males and 26.5 metres for females, which makes the Westport animal a modest example of the largest creature that has ever lived.
What makes a dead blue whale on a West Coast beach scientifically valuable is how little is still known about the ones that live here. For decades blue whales seen in New Zealand waters were assumed to be passing through on their way somewhere else. That changed after Leigh Torres of Oregon State University’s Marine Mammal Institute put forward the idea in 2013 that there was an undocumented feeding ground in the South Taranaki Bight, the stretch of water between Taranaki, Whanganui and the top of the South Island.
Torres and her colleagues ran vessel surveys in the summers of 2014, 2016 and 2017 and left underwater microphones in the bight recording whale calls for two full years. Photographs of individual whales, genetic samples taken by biopsy dart and the acoustic record all pointed the same way. In a 2018 paper in the journal Endangered Species Research, the team documented a population of blue whales that is genetically distinct from other blue whales and present in New Zealand waters all year round, with a minimum abundance estimate of 718 animals.
Their main feeding ground also happens to sit in the most industrialised patch of ocean in the country, with oil and gas extraction, seismic surveying, heavy shipping traffic and a proposed seabed mine all in the same waters. The discovery led to calls for the bight to be declared a marine mammal sanctuary.
The Westport whale washed up on the other side of the South Island, so it is not known whether it belonged to that resident population or was one of the pygmy blue whales that pass New Zealand on longer migrations, some of them swimming through Cook Strait. Genetic work on the tissue samples DOC has collected is the sort of evidence that can answer that question, which is why samples are taken even when a carcass is buried within a day or two.
DOC classes blue whales in New Zealand as Nationally Vulnerable and puts the number in local waters somewhere between 1,000 and 5,000. The department lists three main threats, which are underwater noise, climate change and being struck by ships.
That last threat is on display in Wellington. The pygmy blue whale skeleton hanging in Te Papa’s Mountains to the Sea gallery is a 20.6 metre subadult male that was hit by a container ship off North Cape in 1994. It took two years of flensing, treating, bleaching and steam cleaning before the bones were reassembled in the museum in October 1996, and it has been the closest most New Zealanders get to a blue whale ever since.
For a few days this week, a small West Coast town had the real thing. DOC has asked anyone who spots a whale at sea to report it, because sighting records remain one of the simplest ways of building a picture of where these animals go and when.
Have you seen the whale at Carters Beach, or come across a stranding on your own local beach? Leave a comment below and tell us what you saw.
This article was written by AI, briefed to report the facts, hopefully without some of the bias people bring to the job 🙂
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