By Daniel Lawler
The world’s largest whale graveyard has been discovered at the bottom of the Indian Ocean by Chinese scientists, who found that the vast expanse of young and ancient carcasses supports large communities of deep-sea life.
It is also the deepest and oldest known whale graveyard on Earth, according to research published in the journal Nature on Wednesday, with some fossils dating back 5.3 million years.
From inside a small submersible, Chinese researchers saw a variety of strange animals – many believed to be new to science – living off whale carcasses.
A new, albeit extinct, species of whale was also identified among nearly 500 skeletons found up to 7,000 meters deep along a 1,200 kilometer corridor of bones in the Indian Ocean west of Australia.
Lead study author Xiaotong Peng of the Chinese Academy of Sciences told AFP the researchers were “surprised” when the scale of their discovery became clear.
It was known that when whales die and fall to the bottom of the sea, their drowned bodies – called “whale droppings” – provide a food source for bottom-dwelling creatures.
“But the discovery of a necropolis of this scale was completely unexpected: the size of the distribution, the depth and the age range were far beyond anything we had imagined,” Peng said.
Researchers had several theories as to why so many whales died in this particular corridor, including that it is a popular foraging area and has a V-shaped trench that dumps the carcasses to the ocean floor.
‘Truly incredible experience’
For the discovery, diver Fendouzhe made 32 dives in 2023 – although what she found was only FOUND outdoors on Wednesday.
The submarine took up to three people on the dive, collecting fossil samples using robotic arms.
Study co-author Zhou Peng said witnessing the whale graveyard “was a truly incredible experience.”
“The living ecosystems we saw offered a completely different perspective on this otherwise dark and cold ocean floor.”
Among the animals they found living off the corpses were jellyfish, worms, snails, crustaceans, brittle stars and molluscs called bivalves.
Extrapolating from the number of bones they found, most of which were from beaked whales, the scientists estimated that there could be more than 10 million carcasses in the entire area called the Diamantina Zone.
The soft tissue and lipids inside those many corpses “translate to approximately 6.7 million tons of sequestered carbon,” Xiaotong Peng said.
This provides an incredible source of food for animals, similar to how hydrothermal vents create their own ecosystems on the ocean floor.
Some of the animals seen by scientists also live in hydrothermal vents and cold seeps, suggesting that whale carcasses may help connect these deep-sea communities to one another.
While this is by far the largest whale graveyard found so far, fossils found during the hunt suggest there may be others outside South Africa, the Iberian Peninsula and the Crozet Islands, according to the study.
‘More blockbusters to come’?
University of Hawaii oceanographer Craig Smith, who discovered the first whale fall in 1987 but was not involved in the new research, told AFP it was “extremely exciting”.
“The sheer number of documented whale fossils, including a new species of beaked whale, is truly amazing and of great importance to understanding the evolution of whales and the distribution of whales over geologic time,” he said.
Whale decline researcher Amy Baco-Taylor at Florida State University told AFP the “remarkable discovery” “is likely to provide a lot of new knowledge”.
“It seems very strange” that so many whales died in the area, Baco-Taylor admitted, adding that “we don’t know enough about whale consciousness.”
American paleontologist Stephen Godfrey compared the “truly unique discovery” to past major underwater finds, such as when scientists first identified life-filled hydrothermal vents on the ocean floor in 1977.
He called for future dive trips to find more whale cemeteries around the world.
This discovery “reminded me of a trailer for the first in a series of epic films,” Godfrey commented in a paper affiliated with Nature.
“I hope there will be many more of these blockbusters.”
