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You might think that a volcano would not be the most hospitable place for living organisms. However, the Borealis mud volcano at a depth of 400 m is a haven for a number of marine species. The Borealis mud volcano, an underwater volcano in the Barents Sea, was first discovered in 2023 by researchers from the Arctic University of Norway UiT. The discovery attracted significant attention worldwide, thanks to the widespread dissemination of images of the volcano. Now, in collaboration with REV Ocean, UiT researchers have published the results of an interdisciplinary study that has shown that the Borealis mud volcano serves as a vital ecological refuge for various marine species in the Barents Sea.
Although some areas of the crater floor appear inhospitable to many organisms, carbonate crusts—minerals that have formed over millennia—provide a hard substrate that supports marine life. These crusts create a habitat for species such as anemones, serpulid worms, demosponges, and sparse colonies of octocorals.
"Important for biodiversity conservation"
In addition, carbonates offer both shelter and feeding opportunities, playing an important role in supporting local fish populations. Researchers observed large schools of commercially valuable species such as pollack and a variety of demersal species such as spotted wolffish, cod, four-bearded rockfish and redfish (Sebastes spp) congregating around the jagged carbonate formations.
"The perch, for example, is listed in the Red Book and we do not know what the consequences would be if it disappeared. The Borealis is an oasis where different species can grow and thrive. Therefore, the preservation of ecosystems such as the Borealis mud volcano is essential for maintaining biodiversity and understanding the interactions between geology, geochemistry and biology in the marine environment. We need this understanding, among other things, given that the Arctic seabed plays an important role in oil and gas production activities and the development of deep-sea mining," says Professor Giuliana Pagnieri, lead author of the study, recently published in Nature Communications..
Methane has been leaking, probably for thousands of years
Aboard the research vessel Kronprins Haakon in May 2024, researchers confirmed their previous findings. Using the remotely operated vehicle ROV Aurora, the research team was able to make a series of observations of the underwater volcano. Among other things, they saw that it was heating the surrounding environment to 11,5 degrees Celsius, while the seafloor is usually around 4 degrees Celsius.
The researchers also found sediments containing extinct microscopic marine organisms up to 2,5 million years old, and that small "mud cones" in the volcanic system are spewing energetic fluids rich in methane. The fact that the seafloor around the volcano is also characterized by large carbonate deposits suggests that the methane has likely been leaking for thousands of years.
«"The Borealis Mud Volcano is a unique geological and ecological phenomenon that provides a rare insight into the complex interactions between geological processes and marine ecosystems. It is important to preserve these unique habitats, which play a crucial role in supporting marine biodiversity," says Panieri.
She recalls that in the long term, Norway has committed to achieving the 30×30 target (protecting 30% of land and sea by 2030) for spatial conservation measures for representative marine ecosystems, including in the deep sea. Protecting large areas of the deep seabed along the Norwegian coast could result in seeping refugia acting as a source of populations for broader recolonization and restoration of benthic biological communities.
“The new discoveries show the power of international collaboration and how such collaboration can contribute to improving our understanding of the world’s oceans,” says Panieri.
