Arctic deep-sea oasis with thriving life discovered 2.5 miles below surface

Nearly two and a half miles beneath the surface of the Arctic Ocean, where the pressure would crush most life and the temperature hovers just above freezing, an international team of researchers found something that should not exist: a thriving city of organisms living in absolute darkness, sustained not by sunlight but by the chemical energy of methane and oil seeping from the seafloor.

The discovery, led by Giuliana Panieri of UiT The Arctic University of Norway and Jonathan Copley of the University of Southampton, centers on what scientists call the Freya mounds—the deepest known methane hydrate ecosystem ever recorded. Located on the Molloy Ridge in the Greenland Sea, these conical formations of frozen methane and oil rise as much as six meters from the seabed, releasing streams of gas bubbles that climb more than three kilometers through the water column. The expedition took place in May 2024 using a remotely operated vehicle named Aurora, and the findings were published in Nature Communications in December 2025.

What Aurora's cameras revealed was an otherworldly landscape populated by more than twenty species. Dense forests of Sclerolinum tube worms crowd around the mounds alongside caridean red shrimp, amphipods, polychaete worms, and various crustaceans. These organisms have adapted to survive in an environment that previous scientific understanding suggested should be nearly barren. They depend entirely on chemosynthesis—bacteria in the ecosystem use methane and sulfide as energy sources, forming the foundation of a food web that sustains everything above it. The gas rising from the mounds contains not just methane but also ethane, propane, and butane, chemical signatures pointing to sources deep within the Earth's crust, some originating from ancient plant material millions of years old.

The scale of the discovery reshapes what scientists thought possible in the deep ocean. Previous methane seeps had been found only in waters shallower than two thousand meters. The Freya mounds sit at nearly four thousand meters, making them the deepest cold seeps ever documented in the Arctic. The methane plumes themselves rank among the tallest gas flares ever observed anywhere on Earth. Panieri described the moment of discovery with undisguised wonder: seeing several of these mounds simultaneously, each filled with gas hydrates and surrounded by dense clusters of organisms, felt almost unreal. "It was crazy," she told reporters. "At a water depth of almost 4,000 meters, you have these dense oases of organisms."

The timing of this discovery carries weight beyond pure science. In early 2024, Norway opened the Arctic seabed in this region to mineral exploration, a move that triggered immediate concern from conservation advocates and scientists. The potential extraction of valuable minerals from the deep ocean floor could devastate ecosystems like Freya before humanity even understands what lives there. Following public pressure and legal challenges, Norway agreed in late 2025 to pause issuing new mining licenses and suspend public funding for seabed mineral mapping through at least the end of 2029. But the pause is temporary—currently set to last only four years.

Copley and his colleagues argue that deep cold seeps require the same protective status already granted to hydrothermal vents in other parts of the world. "Research has already established that hydrothermal vents must be protected from deep-sea mining anywhere in the world, because of the unique colonies of species that live around them," Copley said. "Our study indicates that deep cold seeps in the Arctic will need similar protection." He noted that other deep bubble plumes have already been detected near the Freya mounds, suggesting more undiscovered ecosystems await exploration in the region.

The discovery also carries implications for understanding how carbon moves through Earth's systems. These methane seeps play a role in global carbon cycling, and the organisms that thrive around them represent a previously unknown piece of that puzzle. Panieri emphasized that the seafloor remains almost entirely unknown to science. "There is so much to be investigated," she said. "Every time that we have the possibility to see the seafloor, we discover something new." The question now is whether humanity will take time to understand what exists in these deep places before deciding to extract resources from them.