Vast 'Whale Graveyard' Stretching 1,200 km Discovered at 7,000 m Depth in Indian Ocean Deep Sea

Research Team Discovers Whale Graveyard on Indian Ocean Seafloor
485 Sites with Whale Fossils and Whale Fall Traces, 5 Active Biological Communities
"A Fossil Repository for Tracing Animal Evolution"

It has been confirmed that a vast "whale graveyard," stretching from fossils dating back approximately 5.3 million years to the present, exists on the deep-sea floor at depths of 4,600 to 7,000 meters in the southeastern Indian Ocean. This is the deepest and most extensive whale carcass accumulation site known to date, providing new clues about deep-sea ecosystems and whale evolution.

Whale carcasses found at a deep-sea whale graveyard in the Indian Ocean. Nature

According to Yonhap News on June 11, an international research team from Italy and New Zealand, led by Dr. Feng Xiaotong of the Chinese Academy of Sciences, published their findings in the scientific journal "Nature" the previous day. They reported the discovery of a massive whale graveyard at depths of 4,616 to 7,000 meters on the seabed of the "Diamantina Zone" in the southeastern Indian Ocean. The newly discovered graveyard is believed to stretch more than 1,200 kilometers along the seafloor.

The deep sea is home to a variety of organisms that have adapted to extreme environments. One intriguing phenomenon is the "whale fall" ecosystem, which forms when a dead whale's carcass sinks to the sea floor. This is sometimes referred to as a "biodiversity oasis" of the deep sea, where numerous organisms gather to use whale bones and organic matter as energy sources. To date, about 70 such sites have been reported in various oceans and depth zones, but their distribution is regionally uneven and discoveries have been sporadic, so the actual ecology remains insufficiently understood.

In 2023, while exploring the Diamantina Zone with the research vessel Fundouzhe, the team first identified a whale fossil at a depth of 7,002 meters. Through 32 subsequent dives, they confirmed 485 sites containing whale fossils and traces of whale falls between 4,616 and 7,001 meters deep. Among these, five sites were found to host diverse biological communities.

Whale carcasses and surrounding ecosystems discovered at a deep-sea whale graveyard in the Indian Ocean. Nature

The deepest whale fall was a beaked whale carcass found at a depth of 6,789 meters, and the skeleton of a 5-meter-long Antarctic minke whale (Balaenoptera bonaerensis) was also identified. Unique biological communities were observed around the carcasses, including spider starfish, Osedax worms (which bore into bones), and bivalves that live in symbiosis with chemosynthetic bacteria. The research team stated, "The large invertebrates found belong to 35 taxonomic groups, and many of them are likely to be new species previously unreported in the scientific community."

Most of the fossils were of beaked whales specialized for deep-sea diving, including numerous fossils of living species such as Andrews' beaked whale (Mesoplodon bowdoini) and strap-toothed whale (Mesoplodon layardii). Alongside already known extinct species, a new extinct beaked whale species, "Pterocetus diamantinae," was also identified.

Isotope dating of 33 fossils showed the oldest to be about 5.26 million years old. This indicates that whale falls have continuously occurred in this area at least since the early Pliocene, 5.3 million years ago.

The research team commented, "This discovery extends the previously known depth range of whale fall ecosystems by more than 2,500 meters." They added, "It supports the hypothesis that whale falls serve as stepping-stone habitats that facilitate the evolution and dispersal of deep-sea chemosynthetic biological communities." Furthermore, they noted, "Some deep-sea seabeds also act as fossil repositories that can trace the evolution of cetaceans on a geological time scale."

This content was produced with the assistance of AI translation services.