Chinese research team finds wonders in the deep

In a groundbreaking scientific discovery, Chinese researchers exploring the ocean's deepest realm have found thriving biodiversity despite of the harsh conditions of the deep.

The extraordinary findings were revealed at a news conference in Sanya, Hainan province, on Friday.

The cover of the journal Cell on Thursday showcased a commentary and three research papers delving into the ecological wonders of the hadal zone, where water depths exceed 6,000 meters. The revelations stem from the ongoing Mariana Trench environment and ecology research project, a collaborative effort initiated in 2021 by Shanghai Jiao Tong University, the Institute of Deep-sea Science and Engineering of the Chinese Academy of Sciences, BGI Group and other esteemed Chinese scientific institutions.

Despite the environmental challenges of immense pressures, utter darkness and limited resources, diverse life forms flourish — including microorganisms, amphipods and fish.

Through collaborative efforts, scientists have discovered unique adaptation strategies among these deep-sea organisms. The research team identified a specialized food chain and discovered distinct evolutionary traits that enable survival in the abyss. Notably, the hadal microbial community exhibited extraordinary diversity, with over 7,564 newly identified species-level genomes.

Among the discoveries was the genetic makeup of Hirondellea gigas, an amphipod species that thrives at extreme depths. The team unveiled the first genome of this deep-sea animal, which shed light on its ability to withstand the high water pressure. Additionally, genetic analyses of deep-sea fish species highlighted the ways they have adapted to survive, including unique genetic transformations for stable gene expression under extreme pressure.

But the work also revealed findings of concern — industrial pollutants in fish and in sediment samples from the Mariana Trench and the Philippine Trench — underscoring the human impact, even in such a remote environment.

The research significantly advances the world's understanding of life in the ocean's deepest parts and offers insights into the mechanics of biodiversity and evolutionary adaptations in these ecosystems. All genomic data generated by the research covering deep-sea microbes, amphipods and fish has been made openly accessible to the global scientific community.

Xu Xun, director of BGI-Research, emphasized the importance of the research in redefining human understanding of deep-sea life and the responsibility it entails. The studies unveil not only secrets of evolution but also provide critical insights for the sustainable stewardship of Earth's ecosystems.

"Our research offers valuable insights that could potentially inform our understanding of the possibility of alien life forms in other planetary ecosystems," Xu said.