The Freya gas hydrate deposits were discovered during the Ocean Census Arctic Deep EXTREME24 expedition, led by researchers from the Arctic University of Norway (UiT). Gas bubbles in the water column alerted scientists to unusual activity deep beneath their ship, prompting them to send a remotely operated vehicle (ROV) to investigate, Index reports.
At the bottom, they encountered exposed clumps of crystalline material known as gas hydrate – a frozen mixture of methane and water, held in a solid state by high pressure and low temperatures. The ROV collected samples of methane, crude oil and sediment that contained a surprising variety of marine life.
“This discovery is a game-changer for Arctic deep-sea ecosystems and carbon cycling,” said expedition co-leader Giuliana Panieri. “We found an ultra-deep system that is geologically dynamic and biologically rich, with implications for biodiversity, climate processes and future management of the High North.”
The deep-sea animals that inhabit the Freya clusters are not dependent on the Sun. Instead, they feed on chemotrophic microbes that turn chemicals like methane, sulfides, and other hydrocarbons into biofuel. It is precisely these substances that flow from the seabed in newly discovered locations.
Among the animals discovered are tube worms, prawn-like crustaceans, polychaetes and bivalves.
Scientists point out that this ecosystem is similar in composition to arctic hydrothermal springs at similar depths. Compounds found in the sediment suggest that the oil and gas came from flowering plants that grew in the once warm and forested Greenland during the Miocene, 23 to 5.3 million years ago.
Such carbon-rich deposits make Freya an ideal habitat for specialized organisms, but also a target of interest for the mining industry and some governments. Although deep-sea mining has so far focused on polymetallic nodules rich in rare minerals, gas hydrates represent a potential energy resource.
“Despite significant progress in understanding the distribution and concentration of gas hydrates, a major challenge remains the assessment of gas hydrates as an energy resource and their role in global climate change,” state the authors of the study published in the journal Nature Communications.
Scientists warn of the dangers that such activities represent for fragile and still insufficiently researched ecosystems.
“There are probably more very deep cold springs like Freya waiting to be discovered, and the marine life that thrives around them could be key to the biodiversity of the deep Arctic,” said marine ecologist Jon Copley of the University of Southampton, who took part in the expedition.
“The links we found between life at this source and hydrothermal vents in the Arctic indicate that these island-like habitats on the ocean floor will need to be protected from any future impacts of deep-sea mining in the region,” Copley concluded.
(Vijesti.ba)
