NEW YORK — A recent underwater expedition has uncovered a vibrant ecosystem of organisms thriving within the depths of oceanic trenches. These environments are characterized by punishing pressure, limited food sources, and the absence of light, posing significant survival challenges. While scientists have long understood that tiny microbes are able to thrive in such harsh conditions, there has been less certainty about the existence of larger marine organisms.
On this mission, researchers explored the Kuril–Kamchatka and Aleutian trenches in the northwest Pacific Ocean using a submersible vehicle. Astonishingly, they discovered communities of tubeworms and mollusks flourishing at depths exceeding 31,000 feet (9.5 kilometers) beneath the surface, not far from the ocean’s deepest point at around 36,000 feet (11 kilometers).
These findings provide confirmation that larger organisms inhabit these extreme depths, expanding on previous assumptions and hypotheses. Julie Huber, a deep-sea microbiologist from Woods Hole Oceanographic Institution, noted that the abundance and diversity of these creatures present in such isolated and inaccessible locations were particularly intriguing. “Look how many there are, look how deep they are,” she exclaimed, highlighting the novelty of exploring such remote oceanic regions.
The researchers shared their findings in the scientific journal Nature. In the absence of sunlight to facilitate photosynthesis, these deep-sea organisms rely on carbon and other key elements that descend from the ocean’s upper layers. The scientific team suspects that microorganisms within this newly uncovered ecosystem may be utilizing accumulated carbon deposits in the trenches, metabolizing it to form chemicals that emerge through ocean floor fissures. The tubeworms and mollusks likely sustain themselves by feeding on these microorganisms or by forming symbiotic relationships and benefiting from their chemical production.
Future research endeavors aim to delve into the adaptations these deep-sea organisms have developed to endure such challenging environments. Study authors Mengran Du of the Chinese Academy of Sciences and Vladimir Mordukhovich of the Russian Academy of Sciences emphasized that this discovery questions prior assumptions regarding life’s capability to exist at such profound depths.