On board the manned submersible Fendouzhe, an international team explored the Northwest Pacific Ocean, reaching a depth of 9,533 meters. There, ecosystems of animals living in symbiosis with chemosynthetic bacteria were identified, capable of transforming methane and hydrogen sulfide into energy without the need for sunlight.
This type of metabolism, known as chemosynthesis, had been observed at shallower points, but never with such diversity or at such depth.
Marine trenches as epicenters of extreme biodiversity
The research, published in Nature and coordinated by the Institute of Deep-Sea Science and Engineering of the Chinese Academy of Sciences, focused on two seismically active regions:
- Kuril-Kamchatka Trench, recently hit by an 8.8 magnitude earthquake
- Aleutian Trench, with natural gas seepages from the subsurface
In both, tubeworms up to 30 cm long were found, ranging in color from white to deep red, and completely white clams exceeding 23 cm.
These species form organized structures, not isolated enclaves, suggesting a wider distribution of chemosynthetic life on the ocean floor.
Beyond the known: potential new species and unprecedented metabolism
According to marine biologist Xiaotong Peng, the conditions in these trenches combine extreme cold, absence of light, and high tectonic activity, creating a chemically active environment. Lead researcher Mengran Du highlighted that the revolutionary aspect is not only the achieved depth, but the abundance and diversity of life observed.
Some specimens could belong to new species for science, although genetic analyses are needed to confirm this.
Life based on organic remains: other species adapted to the abyss
In addition to chemosynthetic organisms, species feeding on descending organic detritus were identified, such as:
- Spoon worms
- Abyssal anemones
- Sea cucumbers adapted to extreme pressure
These creatures exhibit poorly understood physiologies, adapted to an environment where life seemed improbable.
Scientific and astrobiological implications of chemosynthetic ecosystems
This discovery expands the known limit for life based on chemosynthesis and reinforces the idea that the deep ocean floors still host unknown life forms, with the potential to redefine extreme biology.
According to the team, the next step will be to understand how these organisms process chemical compounds under extreme pressures, and what molecular mechanisms allow them to survive.
Exploration of the abyss not only reveals unprecedented biodiversity, but also raises new questions about life on other planets, where similar conditions could allow life forms independent of sunlight.
