The world’s largest cetaceans of whales have been discovered at the bottom of the Indian Ocean by Chinese scientists, who have discovered that a large area of new and ancient carcasses supports large communities of deep-sea life.
It is the deepest and oldest known whale burial in the world, according to research published in the journal Nature on Wednesday, with some bones dating back 5.3 million years.
From a small underwater site, Chinese researchers have seen many unusual animals – many believed to be new to science – living on whale carcasses.
A new species of whale, albeit extinct, has been discovered among nearly 500 bones found up to 7,000 meters deep in a 1,200 kilometer long bone tunnel 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 findings became clear.
It was known that when whales die and sink to the bottom of the ocean, their dead bodies – called “whale falls” – provide a food source for deep sea creatures.
“But finding a necropolis of this scale was completely unexpected: the distribution size, depth and age range were more than we thought,” Xiaotong Peng said.
Global TRenD, IDSSE with AP
It is believed that the whales died in such high numbers in this area because it is a popular feeding ground — and it has a V-shaped channel that carries the carcasses to the bottom of the sea.
“A truly amazing experience”
With the discovery, the Fendouzhe submersible has made 32 dives in 2023 – although its findings were revealed in Nature on Wednesday.
The sub took up to three people to the depths, collecting sediment samples using robotic arms.
Study co-author Peng Zhou said seeing the whale graves was “truly unbelievable”.
“The living organisms we saw gave a completely different view of this dark and cold ocean.”
Among the animals they find living on dead bodies are jellyfish, brittle stars, bone-boring worms and molluscs called bivalves.
Most of the 485 fossils the scientists documented were from a variety of beaked whales.
In addition to the number of bones they found, scientists estimate that there may be more than 10 million bodies in the entire area, called the Diamantina Zone.
This study includes a map showing the distribution of whale fossils and whale falls in the Diamantina area and detailed illustrations of fossil crania.
Global TRenD, IDSSE with AP 
The soft tissue and lipids inside those many carcasses “translate to about 6.7 million tons of fixed carbon,” Xiaotong Peng said.
This provides a great 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 tropical and subtropical climates, suggesting that whale carcasses may help connect these deep-sea communities.
“The results support the hypothesis that deep-sea whale falls serve as evolutionary and biogeographic stepping stones for sulfide-dependent species in the deep sea,” the study authors wrote.
Although this is the largest burial found, fossils found during trawling suggest that “similar hidden histories may be widespread in the deep sea,” the study said.
“An Amazing Discovery”
Xikun Song, a biologist at the China Academy of Sciences’ Institute of Deep-sea Science and Engineering, told The Associated Press that the whale’s size and the unique chemistry of its bones are the key to creating these unique underwater habitats.
“At the same time, the deep ocean environment makes these areas very difficult for scientists to find,” said Song, who participated in the latest discovery, wrote in an email.
University of Hawaii oceanographer Craig Smith, who discovered the first whale crash in 1987 but was not involved in the new study, told AFP it was “very exciting.”
“The large number of fossil whale lands, including new species of beaked whales, is truly amazing and very important for understanding the evolution of whales and the distribution of whales in geologic time,” he said.
Whale fall researcher Amy Baco-Taylor at Florida State University told AFP that the “amazing discovery” will “provide a lot of new information.”
This includes animals living in these “chemosynthetic” communities, whose numbers are thought to have been greatly reduced by human whaling, he added.
American paleontologist Stephen Godfrey compared this “really unique discovery” to previous major underwater discoveries, such as when scientists first identified thermal vents teeming with sea life in 1977.
He called for future underwater expeditions to find other whale graves around the world.
The findings “reminded me of the first trailer for a series of superhero movies,” Godfrey said in a related Nature paper.
“I hope there will be many more of these to come,” Godfrey wrote.
The discovery was announced a few weeks after the Chinese Academy of Sciences reported that the world’s oldest known fish fossils were found in China – one was three centimeters long and the other was “the largest animal of its time,” researchers said.
