‘Remarkable Discovery’ of Life Beneath Hydrodermal Vents Is Another Argument for Protecting the Deep Ocean

Scientists have discovered a new ecosystem beneath hydrothermal vents inside cavities of a well-explored undersea volcano. The volcano is located on the East Pacific Rise off the coast of Central America.

An international team of scientists from Slovenia, Costa Rica, France, Germany, the Netherlands and the United States, led by Dr. Monika Bright, an ecologist at the University of Vienna, took a month-long expedition on board Schmidt Ocean Institute (SOI)’s Falkor (too) research vessel, a press release from SOI said.

The research team used the ocean institute’s underwater remotely operated vehicle SuBastian to turn over chunks of volcanic crust to find cave systems housing snails, worms and chemosynthetic bacteria thriving in water that was 75 degrees Fahrenheit.

For the past 46 years, scientists have studied microbial life living in the subsurface, but had never searched for marine animals underneath the warm volcanic vents.

“The deeper you go, the warmer it goes, the less oxygen there is, the more toxic chemicals are in it,” Bright said, as The New York Times reported. “It’s very shallow, but it’s still below the Earth’s crust.”

The team found evidence that tubeworms — a foundational animal of hydrothermal vents — and other vent animals travel through vent fluid beneath the seafloor to colonize new habitats, the press release said. Not many tubeworm offspring were found in water above the vents, which led the researchers to think they might travel under the surface to create new populations.

“Our understanding of animal life at deep-sea hydrothermal vents has greatly expanded with this discovery,” Bright said in the press release. “Two dynamic vent habitats exist. Vent animals above and below the surface thrive together in unison, depending on vent fluid from below and oxygen in the seawater from above.”  

Hydrothermal vents flow like underwater hot springs through cracks made by tectonic activity. Ecosystems follow new hydrothermal vents, colonizing them within a few years. Scientists don’t yet know how the larvae discover new vent fields.

The team used the underwater robot to confirm that animals move through vent fluids. They did this by gluing mesh boxes on top of cracks in the crust. After several days, the boxes and crust were removed to reveal animals living underneath in hydrothermal cavities.

“On land we have long known of animals living in cavities underground, and in the ocean of animals living in sand and mud, but for the first time, scientists have looked for animals beneath hydrothermal vents,” said Dr. Jyotika Virmani, executive director of SOI, in the press release. “This truly remarkable discovery of a new ecosystem, hidden beneath another ecosystem, provides fresh evidence that life exists in incredible places. Schmidt Ocean Institute is proud to have provided a platform for Dr. Bright and her team to gather new insights into these systems that may be vulnerable to deep-sea mining.”

Los Angeles-based artist Max Hooper Schneider accompanied the research team on the expedition. Hooper Schneider made sculptures that were filmed on the vent systems, and will incorporate the artistic research into future exhibits.

“Lightless ecosystems of the deep ocean are imperative to understanding the extremophilic dawns of planet earth,” Hooper Schneider said in the press release.

Wendy Schmidt, president and co-founder of SOI, said the expedition’s discoveries show how important it is to explore the ocean’s depths to understand what life exists there.

“The discovery of new creatures, landscapes, and now, an entirely new ecosystem underscores just how much we have yet to discover about our Ocean — and how important it is to protect what we don’t yet know or understand,” Schmidt said in the press release.