Life Thrives in the Deepest Ocean: New Discoveries from the Mariana Trench

SHENZHEN, China, March 7, 2025 /PRNewswire/ -- The latest scientific research at the deepest part of the ocean has revealed something extraordinary - biodiversity is extensive and flourishing despite the extreme conditions.

On March 6, the scientific journal Cell, featured a cover story, systematically revealing the ecological characteristics of the hadal zone at water depths exceeding 6,000 meters. These findings mark the latest results from the Mariana Trench Environment and Ecology Research (MEER) Project, a collaboration launched in 2021 by Shanghai Jiao Tong University, the Institute of Deep-sea Science and Engineering (IDSSE) of the Chinese Academy of Sciences, BGI Group, and other Chinese scientific institutions.

"Our study not only redefines our understanding of the limits of deep-sea life but also unveils an 'extreme survival manual' written through hundreds of millions of years of evolution," explained Dr. Xun Xu, Director of BGI-Research, the scientific research arm of BGI Group.

The hadal zone, while covering just 1–2% of the ocean floor, accounts for the deepest 45% of the ocean's vertical depth. It is a realm of extreme conditions, where immense pressure, total darkness, limited food sources, and near-freezing temperatures create an environment that commonly considered inhabitable by only a few specialized organisms.

The findings uncovered an extraordinary diversity of hadal microorganisms, with over 7,564 newly identified species-level genomes, nearly 90% of which had never been documented in public databases.

The microorganisms have developed a unique set of evolutionary traits for energy intake and pressure resistance in order to survive at the deepest sea levels.

Beyond microorganisms, the research team made fascinating discoveries about an amphipoda species that thrives at depths of 6,800 to 11,000 meters - where pressure is equivalent to balancing an SUV on a fingertip.

The researchers also examined 11 species of deep-sea fish, uncovering remarkable genetic adaptations that allow them to survive in extreme depths.

One of the most surprising findings challenges a long-standing scientific assumption about deep-sea adaptation. Previous research suggested that trimethylamine-N-oxide (TMAO), a compound that stabilizes proteins under high pressure, increases in fish as depth increases. However, this study found no significant rise in TMAO levels in fish living below 6,000 meters.

All genomic data generated by this research has been made freely accessible to the global scientific community through online platforms.