A team of rearchers lead by the Chinese Academy of Sciences have discovered the world’s deepest and largest collection of whale remains on the ocean floor.
A “whale fall” is when the carcass of a whale has sunk onto the ocean floor. These carcasses create rich, temporary habitats for deep-sea creatures, supporting everything from bone-eating worms to sea stars.
The site, located in the Diamantina Zone of the southeastern Indian Ocean at depths of up to 7,000 meters includes both ancient fossils and active whale-fall ecosystems. Using strontium isotope dating, the researchers confirmed that the fossils date back at least 5.3 million years to the Early Pliocene. This represents the deepest active whale-fall ecosystem ever recorded.
The scientists carried out 32 dives using a manned deep-sea submersible operating from the Chinese research vessel Tansuo-1. They explored a 1,200-kilometer stretch of the Diamantina Zone and found five active whale falls and 476 fossil sites, ranging from 4,616 to 7,001 meters deep.
The density of whale remains reached up to 759.5 individuals per square kilometer. If that number is extrapolated across the entire zone, it suggests there may be more than 10 million whale carcasses in the area. The research found that very low sedimentation rates at these depths kept the bones exposed on the seabed for long periods, helping to preserve them.
The scientists also calculated the carbon impact of the roughly 10 million carcasses could represent about 6.7 million tonnes of sequestered carbon. This suggests that whale falls are a major, previously overlooked source of carbon on the deep-ocean floor, capable of shaping the region’s food web and biodiversity.
Until now, most known whale falls were found at depths of less than 4,000 meters, with the deepest active site recorded at 4,204 meters. No active whale-fall ecosystem had ever been reported from hadal depths – which are those deeper than 6,000 meters.
The research was supported by several scientific programs, including the Global Hadal Exploration Program, a ten-year United Nations Ocean Decade initiative led by the Chinese Academy of Sciences (CAS) Institute of Deep-sea Science and Engineering (IDSSE). The Program is dedicated to exploring the deepest regions of the global ocean and addressing fundamental questions about deep-sea geology, life and environmental evolution.
The CAS study was conducted in collaboration with the University of Pisa in Italy and Earth Sciences New Zealand in Wellington, and has been published in the journal Nature.
Source: Edited from CGTN, June 11, 2026. https://news.cgtn.com/news/2026-06-11/5-3-million-year-old-whale-graveyard-hotspot-found-in-Indian-Ocean-1NTjI7Zr8qY/p.html
