Researchers Dive Over 30,000 Feet into Ocean Trench and Film Life
Researchers recently visited some of the deepest oceanic trenches on Earth and photographed an “unbelievable” amount of life in an extremely remote area.
The team descended over 31,000 feet (9.5 kilometers) to explore the Kuril–Kamchatka and Aleutian trenches in the northwest Pacific Ocean which lie between Russia and Alaska. The images they captured were from a high-definition video camera attached to the manned submersible called Fendouzhe.
They found that despite the extreme conditions of high pressure, low temperatures, and the absence of sunlight, there is a thriving ecosystem of larger marine organisms in some of the ocean’s deepest regions.
While it has long been understood that microscopic life can survive in these deep-sea environments, evidence of larger animals has been limited. The recent discovery of tubeworms and mollusks in these depths confirms earlier suspicions and highlights the scale of life in these remote areas, according to Julie Huber, a deep-sea microbiologist at the Woods Hole Oceanographic Institution.
“Look how many there are, look how deep they are,” Huber, who was not involved in the study, tells The Independent. “They don’t all look the same and they’re in a place that we haven’t had good access to before.”
Species identification, density, and spatial distribution were assessed through analysis of video footage captured by two high-definition cameras mounted on a human-occupied submersible.
For each dive, between three and ten screenshots were selected to represent the areas with the highest observed faunal density. The area captured in each image was estimated using the submersible’s laser scale, which projects two parallel laser points 10 cm apart onto the seafloor, providing a reference for spatial measurements.
In the absence of sunlight, organisms in deep-sea trenches cannot rely on photosynthesis. Many depend on organic material, including carbon, that sinks from the upper ocean. However, scientists believe that microbes in this newly discovered ecosystem may be using carbon that has collected in the trench over long periods, converting it into chemicals that seep through cracks in the ocean floor.
According to researchers, tubeworms and mollusks may feed on these microbes or live in symbiosis with them, benefiting from the byproducts of their chemical processes.
Future research will investigate how these animals have adapted to survive under such extreme conditions and the specific mechanisms they use to obtain energy from chemical reactions, according to study authors Mengran Du of the Chinese Academy of Sciences and Vladimir Mordukhovich of the Russian Academy of Sciences.
Their findings challenge “long-standing assumptions about life’s potential at extreme depths,” the researchers say in a joint statement. The work was published in Nature on Wednesday.
Image credits: Institute of Deep-sea Science and Engineering, Chinese Academy of Sciences
