Scientists Uncover Vast Whale Graveyard Deep in the Indian Ocean

An international team of scientists has reported one of the largest and deepest whale graveyards ever found, hidden in the southeastern Indian Ocean. The site stretches for about 1,200 kilometers and is estimated to contain more than 10 million whale remains and fossils, along with fresh carcasses that support an entire deep-sea ecosystem. The findings were published in Nature.

The discovery was made in the Diamantina Fracture Zone, a network of underwater ridges and trenches southwest of Australia that reaches depths of 5,000 to 7,000 meters. Working from the research vessel Tan Suo Yi Hao, the scientists carried out 32 targeted dives and documented 485 fossil deposits and five modern whale carcasses. In some areas, they counted about 760 skeletons per square kilometer, far above anything previously recorded.

Lead researcher Feng Zhu of the Institute of Deep-Sea Science and Engineering at the Chinese Academy of Sciences in Beijing said, “By our estimates, more than 10 million whale remains lie on the ocean floor in this trench. A huge amount of additional bones may be buried deeper under seabed sediments.” The team used the robotic arm of the Chinese submersible Fendouzhe to recover dozens of 5.3-million-year-old fossils, alongside living scavengers that feed on bones.

Among the key finds was part of the skull of a previously unknown extinct whale species, named Pterocetus diamantinae. Other fossils included Pterocetus benguelae, while modern remains belonged to small beaked whales, including Andrew’s beaked whale. Researchers said the trench likely acts as a natural funnel for carcasses, and that the unique V-shaped terrain helps explain why so many beaked whales are found there. Scientists also noted that beaked whales may die when they exceed safe diving depths of around 3,000 meters, likely from exhaustion or decompression sickness.