Scientists uncover complex animal life beneath the ocean floor at a depth of 2500 metres, challenging long-held beliefs

In a groundbreaking study, scientists have discovered animal life thriving beneath the seafloor at an astonishing depth of 2,500 metres (approximately 8,250 feet). This revelation challenges long-held beliefs that only microorganisms inhabit these extreme underwater environments and opens the door to the possibility that more complex lifeforms exist deep within Earth’s crust.


A breakthrough discovery: Life found beneath the seafloor

The discovery was made close to deep hydrothermal vent systems, suggesting that the subseafloor region may harbour a variety of life forms previously unimagined. “Our discovery shows us that animal life in the ocean is not restricted to what we see on the seafloor surface, but that animal life extends into the shallow ocean’s crust,” said Sabine Gollner, a researcher at the Royal Netherlands Institute for Sea Research and co-author of the study published in Nature Communications. The findings enhance the understanding of life's resilience and adaptability, as they indicate that life can thrive even in the most inhospitable conditions. This revelation has sparked excitement among researchers and increased hopes of discovering life beyond Earth.


Methodology behind the discovery

The team conducted their investigation using the remotely operated vehicle (ROV) SuBastian, deployed from the research vessel Falkor (too). The exploration took place at a depth of 2,515 metres across the eastern Pacific Ocean floor. “The extent of the subseafloor cavities—horizontally and how deep they reach—is not known yet,” Gollner explained. “The subseafloor habitat could be very important for the succession at hydrothermal vents, as the seafloor and subseafloor habitats are connected.”



New insights into marine life : The significance of recent discoveries

Among the astonishing findings were various animal species, including tubeworms that were wriggling through cavities in the subseafloor. Notably, scientists identified species such as R. pachyptila, O. alvinae, and the mussels B. thermophilus, along with polychaete worms and limpets.

As stated in the research paper, “The study of the subseafloor biosphere for animal life has just begun. These efforts will lead to a better understanding of hydrothermal vent biogeochemistry, ecology, and evolution and its impact on global biodiversity and connectivity.”
This significant discovery not only broadens the understanding of marine ecosystems but also emphasises the importance of further exploration of the subseafloor biosphere. The findings could lead to better management practices for seafloor surfaces and crustal hydrothermal vents, highlighting the interconnectedness of various habitats within the ocean.

As scientists continue to investigate these uncharted territories, the potential for discovering even more complex lifeforms beneath the seafloor remains tantalisingly close, promising to deepen our understanding of life on Earth and beyond.