Animal life beneath the seafloor
Scientists discover worms and snails in cavities and caves around hydrothermal vents
Scientists discovered significant numbers of animals living in cavities and caves below the deep-sea seafloor, some growing up to half a meter of length. The discovery, which underlines how many secrets still hide in the inaccessible deep sea and how important it is to protect this ecosystem, was aided by the support of data scientists André Luiz de Oliveira from the Max Planck Institute for Marine Microbiology.
Hydrothermal vents have long been known to be thriving with animal life, which is mostly based on the support of chemosynthetic symbiotic bacteria supplying the animals with what they need to live. On a cruise to the East Pacific Rise, scientists around Monika Bright from the University of Vienna, Austria, and Sabine Gollner from the Royal Netherlands Institute for Sea Research have discovered that animals of all sizes also live hidden beneath the bottom of the ocean: Underneath the seafloor around hydrothermal vents, they discovered cave systems teeming with worms, snails, and chemosynthetic bacteria.
“This is quite a revolutionary discovery”, says André Luiz de Oliveira from the Max Planck Institute for Marine Microbiology in Bremen, Germany, who joined the cruise on Schmidt Ocean Institute’s research vessel R/V Falkor (too) in July 2023. “Finding these large animals beneath the seafloor was not only super exciting, but it also shows that the inhabitants of the seafloor and the subseafloor are tightly connected. Moreover, it suggests that the larvae of these animals disperse through the subseafloor – which has been long suspected but never systematically investigated and proven.”
Data management
De Oliveira, a biologist who has long been working in bioinformatics, joined the cruise as a data scientist. The research was carried out with the help of the submersible ROV SuBastian from Schmidt Ocean Institute, which recorded each dive, took samples and carried out experiments. “Every planned dive – 18 dives in total – of the submersible generated up to four Terabytes of data in the form of videos, pictures, samples, tables, and so on. It was my job was to sort and organise all of this to facilitate the subsequent work of the scientists”, de Oliveira says. “I worked very closely with Monika, Sabine and the other researchers, as well as the marine technicians, to set up a customisable web interface.”
Gathering and organising all the collected information in a straightforward manner and connecting it to experiments and analyses onboard enabled the scientists to access the relevant data quickly and efficiently. “We were surrounded by water but drowning in data. My work made it relatively easier for the scientists to navigate in the sea of data that was produced every day and make sense of their experiments.”
Discovery opens up new questions
As the scientists state in their publication, “the discovery of animal life beneath the surface of the Earth’s crust raises questions concerning the extent of these ecosystems, which is larger than what can be seen on the seafloor surface. The study of the subseafloor biosphere for animal life has just begun.” The results now available will allow to better understand the functioning of these fascinating and complex ecosystems as well as their role in global biodiversity and geochemical cycling.
Thus, their publication also highlights the urgency for protection against potential future anthropogenic impact, the authors stress. “This discovery underlines how many secrets still hide in the inaccessible deep sea and how important it is to take good care of these ecosystems”, concludes de Oliveira.
