Jules Verne had dreamed of it! A Chinese submersible discovered molluscs and verses living at almost 10,000 m under the seas, the colonies of the deepest organisms ever observed.
This discovery suggests that other organizations could prosper in the extreme conditions still largely unexplored on our planet, estimates the team of Chinese scientists in an article published Wednesday in Nature.
Most life forms on earth depend on sunlight, essential to photosynthesis. But in the total darkness of the bottom of the oceans, some living beings survive thanks to chemical substances, such as methane, which escapes cracks in the ocean floor. A process called chemosynthesis by scientists.
Last year, the Chinese submersible Fendouzhe (The battant) plunged 23 times in the Mariannes pit in the west of the Pacific Ocean with researchers on board, according to the study in Nature.
They discovered colonies of thousands of tubicoles (whose body is inside a tube) and molluscs called bivalves, to depths ranging from 2500 to 9533 m.
A video published with the study shows whole fields covered with worms, reaching 30 cm long, as well as clusters of molluscs and clams.
Thorny crustaceans, floating marine worms, sea cucumbers, sea lys (crinoids) and other animals have also been observed.
These are “communities based on the deepest and largest known chemosynthesis to date on earth,” said the study.
Since other ocean cavities have similar characteristics, such communities “could be more widespread than we thought before,” say the authors.
They say they have also found “convincing evidence” of methane production by microbes, the tubicoles that tend to regroup around microbial carpets resembling snow.
Gigantic pressure
The publication of the study comes when the controversial question of mining on the high seas is debated at the international level. China and the United States both have expressed interest in the extraction of coveted minerals in the abyss.
The oceanographers warn that the exploitation of a largely unexplored ocean floor – one of the last wild zones on the planet – could decimate fragile and still little understood ecosystems.
Despite recent talks, the International Marine Funds Authority (AIFM), which oversees mining in international waters, has still not adopted rules to supervise this industry.
Chinese media have already reported that the mission of the submersible Fendouzhe Also aimed at carrying out research on “deep waters” materials “.
Only a handful of people were able to visit the bottom of the Mariannes pit, the deepest underwater valley on our planet.
The first explorers reached the pit – a depression in the shape of a deeper crescent than the height of Everest – in 1960.
No other mission was carried out there, until the trip to the background alone, a first, of the American filmmaker James Cameron in 2012. The director ofAbyss had then described an “extraterrestrial” and “sorry” landscape.
The pressure at the bottom of the pit reached more than a ton per square centimeter, almost 1100 times that at sea level.