Study of Newly Exposed Sea Floor Reveals Flourishing Ecosystems
An international team on board Schmidt Ocean Institute’s R/V Falkor (too), working in the Bellingshausen Sea, rapidly pivoted their research plans to study an area that was, until last month, covered by ice, revealing flourishing ecosystems at depths as great as 1300 meters.On January 13, 2025, an iceberg the size of Chicago, named A-84, broke away from the George VI Ice Shelf, one of the massive floating glaciers attached to the Antarctic Peninsula ice sheet. The team reached the newly exposed seafloor on January 25 and became the first to investigate an area that had never before been accessible to humans.The expedition was the first detailed, comprehensive, and interdisciplinary study of the geology, physical oceanography, and biology beneath such a large area once covered by a floating ice shelf. The ice that calved was approximately 510 square kilometers (209 square miles), revealing an equivalent area of seafloor.Using Schmidt Ocean Institute’s remotely operated vehicle, ROV SuBastian, the team observed the deep seafloor for eight days and found flourishing ecosystems at depths as great as 1300 meters. Their observations include large corals and sponges supporting an array of animal life, including icefish, giant sea spiders, and octopus. The discovery offers new insights into how ecosystems function beneath floating sections of the Antarctic ice sheet.Discoveries made by ROV SuBastian reveal biodiversity on the seafloor, offering new insights into ecosystems below sheets of ice. Credit: Schmidt Ocean InstituteThe team was surprised by the significant biomass and biodiversity of the ecosystems and suspect they have discovered several new species.Deep-sea ecosystems typically rely on nutrients from the surface slowly raining down to the seafloor. However, these Antarctic ecosystems have been covered by 150-meter-thick (almost 500 feet) ice for centuries, completely cut off from surface nutrients. Ocean currents also move nutrients, and the team hypothesizes that currents are a possible mechanism for sustaining life beneath the ice sheet. The precise mechanism fueling these ecosystems is not yet understood.The newly exposed Antarctic seafloor also allowed the team to gather critical data on the past behavior of the larger Antarctic ice sheet. The ice sheet has been shrinking and losing mass over the last few decades due to climate change.In addition to collecting biological and geological samples, the team deployed autonomous gliders to study the impacts of glacial meltwater on the physical and chemical properties of the region. Preliminary data suggest high biological productivity and a strong meltwater flow from the George IV ice shelf.The expedition was part of Challenger 150, a global cooperative focused on deep-sea biological research and endorsed by the Intergovernmental Oceanographic Commission of UNESCO (IOC/UNESCO) as an Ocean Decade Action.
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