10 January – 13 February 2025#AntarcticClimateConnections
In austral summer, the Antarctic sea ice recedes, allowing scientists to map and study parts of the seafloor typically covered in ice. But the waters surrounding the Antarctic Peninsula in the Bellingshausen Sea in Antarctica have not been well mapped and studied. It’s not easy to get there, after all. Drs. Patricia Esquete from the University of Aveiro, Portugal, and Aleksandr Montelli from the University College London, UK, will travel to this remote region with an international team of scientists to create the first high-resolution maps of this region and study the animals that dwell here.
The science team will examine seafloor features carved by glaciers over time and study the intricate ecosystems living at the interface between ice and sea. Using these high-resolution maps along with ROV SuBastian, they will advance research on past ice-sheet dynamics, its impact on the Earth’s climate, and Antarctica’s biodiversity. This research will provide critical insights into the stability of the Antarctic ice sheet, affiliated deep-sea ecosystems, and how these systems will be impacted by climate change.
Antarctica, for peace and science
Antarctica belongs to humanity. No single country owns this territory. In 1959, world leaders signed the Antarctic Treaty, which reserved the continent for peace and science. Yet, its waters are remote and inaccessible. This expedition will explore places no humans have ever seen. With about ten percent of ocean life documented and described, understanding how animals reproduce, maintain genetic diversity, and survive is essential to effectively protecting and managing these extreme and fragile ecosystems in our global Ocean.
One of the primary goals of this expedition is to investigate seep and slope species and ecosystem connectivity and compare environments influenced by ice melting in the continent in two geographic areas with different productivity regimes. Scientists will compare the seafloor in nutrient-rich waters upwelling along the Chile Margin, influenced by water from channels and glaciers and Antarctic, where cold water distributes nutrients from the ice melting throughout the water column, and the rapid-moving Antarctic Circumpolar Current isolates animals from those living outside its boundaries. The current extends to depths of 4000 meters, or more than 2.5 miles, and is more than 120 miles wide, disconnecting Antarctic waters from surrounding ocean basins for the last 30 million years.
Understanding the lives of animals and organisms has important implications for conservation — when a population is isolated, the risk of extinction grows dramatically. Scientists must understand how ecosystems are connected or isolated from each other, as well as what ecosystems and species are unique to a place to inform conservation measures such as Marine Protected Areas.
Another science objective for this team is to create high-resolution maps of the polar seafloor. Submarine landforms produced by past ice sheets remain well preserved along the continental shelf here, allowing reconstructions of the past extent, flow, and stability of ice sheets. Over the coming century, the past behavior of the ice sheets will provide critical information for accurate climate and sea-level projections.
A deep-sea frontier
The science team will also study microbial and faunal communities at the sunless methane seep sites in this region. They will observe how these chemosynthetic microbes convert methane into energy and form carbonate rocks and the species adapted to live in these environments. These seeps are known as essential habitats, and the microbes consuming methane keep this greenhouse gas locked in the seafloor and out of our atmosphere. However, as ice sheets rapidly recede, changes in pressure cause the methane to be released, sometimes explosively. Scientists will use new, high-resolution maps to locate areas along the seafloor where retreating ice may have caused large methane expulsions that scarred the seafloor, leaving massive pockmarks in their wake.
In addition to R/V Falkor (too)’s toolbox of instruments for mapping and sample collection, the team will deploy multiple gliders, floats, and moorings to collect physical and chemical water column data. Baited landers with cameras will allow researchers to see how some animals, such as crustaceans called amphipods, move around for feeding and reproduction while also identifying the ones that don’t show up for a free meal. Such clues may help scientists tease out new understanding about biodiversity and connectivity in that area of the seafloor.
The team hopes to discover new species in this remote area. They are eager to characterize the various geo-habitats and physical environments and describe the role of benthic species in nutrient cycling in the area. New high-resolution data on ice-sheet behavior will help predict ice-sheet stability and its contribution to future global sea-level rise. As part of the Challenger 150 Ocean Decade Program, this cruise will contribute to a global effort to fill the gaps in knowledge of the deep ocean, and the expedition team anticipates exciting exploration along a seafloor frontier in this polar corner of our Ocean.
Team
