Close-up of the tentacles on a solitary hydroid, which was found 360 meters beneath the ocean’s surface.
Credit: ROV SuBastian/Schmidt Ocean Institute
A chunk of ice has split from its Antarctic ice shelf to reveal a bustling, never-before-seen ecosystem underneath. The seabed community, which consists of breathtaking corals, sea sponges, isopods, and more, is thought to have survived on ocean currents leading up to its exposure. Scientists are now working to identify the strange species living there.
The ice covering the newly discovered ecosystem belonged to the George VI Ice Shelf, a vast ice shelf “trapped” between the Antarctic Peninsula and Alexander Island. Earlier this year, a piece of ice calved from George VI, creating what NASA’s Earth Observatory refers to as a “potato-shaped [ice]berg” that has since spent the Antarctic summer ricocheting off of the continent’s coastline, driven by ocean currents.
This satellite image depicts the George VI Ice Shelf with the calving iceberg circled in orange.
Credit: NASA Earth Observatory
When the ice shelf calved, an international team of researchers was studying marine ice ecosystems aboard Falkor (Too), an oceanographic research vessel belonging to the Schmidt Ocean Institute (SOI). Patricia Esquete, a marine biologist at the University of Aveiro, said the team quickly “seized upon the moment” by changing their expedition plan and focusing instead on where the rogue iceberg had originated from.
“We didn’t expect to find such a beautiful, thriving ecosystem,” Esquete said in an SOI release. “Based on the size of the animals, the communities we observed have been there for decades, maybe even hundreds of years.”
Sea sponge and anemones clustered 230 meters below the ocean’s surface.
Credit: ROV SuBastian/Schmidt Ocean Institute
Esquete co-led her colleagues in using SOI’s ROV SuBastian to explore the newly exposed seafloor. Eight days of observation revealed an ecosystem that extended as deep as 1,300 meters (4,265 feet) below the ocean surface. In some areas, sponges, corals, and anemones clustered together; in others, icefish, giant sea spiders, and even octopi roved the region’s underwater gullies. The ecosystem could comprise the largest collection of potential new marine species since Falkor (Too)‘s groundbreaking discovery last winter.
Many sub-ice shelf marine communities—including this one—are shielded from sunlight and rain by ice up to 150 kilometers (93 miles) thick. Because of this, many are thought to subsist purely on currents, which move nutrients from place to place like an oceanic conveyor belt. As the researchers work to classify the animals they found under George VI, they’ll also uncover new paths toward the study of nutrient delivery systems responsible for keeping those same creatures alive.
A helmet jellyfish found during the Falkor (Too) expedition.
Credit: ROV SuBastian/Schmidt Ocean Institute
Scientists on the expedition also noted that the iceberg’s calving from George VI was part of a concerning trend. While aboard Falkor (Too), the team studied the Antarctic Ice Sheet, which covers a majority of the continent and has lost mass over the past few decades. Researchers think climate change is to blame—while calving is a natural part of the ice life cycle, the rate at which it occurs can change as Earth’s atmospheric and water temperatures rise.
“The ice loss from the Antarctic Ice Sheet is a major contributor to sea level rise worldwide,” said expedition co-chief scientist Sasha Montelli. “Our work is critical for providing longer-term context of these recent changes, improving our ability to make projections of future change—projections that can inform actionable policies. We will undoubtedly make new discoveries as we continue to analyze this vital data.”