What’s new: Following the discovery of the underwater Borealis Mud Volcano on the Arctic seabed in 2023, researchers have now confirmed that the methane-spewing volcano is home to a diverse array of marine life thriving in the unique habitat.
What the study says:
- In 2023, scientists from UiT The Arctic University of Norway discovered the Borealis Mud Volcano in the Barents Sea, off the northern coast of Norway, at a depth of 400 meters (1,300 feet). Mud volcanoes, as their name suggests, eject mud and also gases and water from beneath Earth’s crust. At the time, the researchers had used a remotely operated vehicle (ROV) named Aurora to take videos and collect samples of sediments, gas and signs of life from the volcano’s multiple craters.
- By analyzing those videos and samples, the researchers have now confirmed that the seafloor within the mud volcano has extensive carbonate deposits. This, the researchers say, indicates that methane has been seeping out in the area, likely for thousands of years. The methane seeps have created “unique habitats” of low-oxygen conditions, the researchers found.
- Besides being a potent greenhouse gas, methane seepage is associated with carbonate crusts that serve as a hard substrate for organisms that are stationary and need to anchor themselves to a surface. The ROV imagery and samples showed there were anemones and tube-dwelling worms called serpudils anchored to the hard carbonate substrates around the volcano; colonies of small marine animals called hydroids on the crater slopes; nudibranchs or sea slugs; and sparse colonies of octocorals.
- Carbonate structures can also serve as natural shelter from bottom trawling and provide feeding opportunities for fish populations, the researchers write. For instance, they observed “large schools” of fish such as saithe (Pollachius virens), spotted wolffish (Anarhichas minor), and several species of redfish (Sebastes spp.) around the carbonate formations. One commonly observed fish is the Atlantic redfish (S. norvegicus), listed as endangered on the Norwegian Red List. The Atlantic redfish is overfished and subject to a fishing moratorium, the researchers write.
- The team also saw lost fishing gear abandoned by bottom trawlers, “snagged on the jagged carbonate rock around the perimeter of the craters.”
What this means:
“Borealis is an oasis where different species can thrive and flourish,” study lead author Giuliana Panieri, a professor at UiT The Arctic University of Norway, said in a statement.
In particular, the researchers call the Borealis Mud Volcano “a de facto sanctuary” for endangered species. So preserving this ecosystem “is essential for maintaining biodiversity and understanding the interactions between geology, geochemistry and biology in marine environments,” Panieri said.
The ecosystem is also important to understand as “the Arctic seabed plays an important role in oil and gas extraction activities and the emerging deep-sea mining industry,” she added.
Banner image of the underwater Borealis Mud Volcano, courtesy of Jørn Berger-Nyvoll/UiT.