Cristian Lagger is exploring some of the coldest, darkest places on the planet
Thousands of feet below the surface, the Antarctic seafloor is a time machine to another realm. Here’s how one scientist brings back lessons from the deep.
From its desolate, frozen crust, Antarctica seems like a place unsuited for life. But just offshore, the depths of the Southern Ocean tell a different story. Hundreds of feet below the surface, there are translucent icefish guarding their eggs, octopuses lolling in the undersea current, and alien-looking isopod crustaceans creeping among a colorful menagerie of sponges and sea stars. “It blows your mind,” says marine biologist and National Geographic Explorer Cristian Lagger. “At the bottom of the sea, Antarctica is a rich continent with many species, colors, textures, and shapes.”
During a recent expedition, Lagger peered into those frigid depths from the control room of the Schmidt Ocean Institute’s research vessel, Falkor (too), as live video from its remotely operated vehicle, SuBastian, streamed on a monitor. His research team had reached a previously undocumented patch of an ocean floor trench, where SuBastian explored a gently sloped area from a depth of more than 3,000 feet to about 1,000 feet. Lagger and his colleagues felt like astronauts exploring a new frontier.
The Southern Ocean plays an outsize role in the health of our planet by absorbing more human-caused carbon dioxide than any other ocean and regulating the climate through its currents and seasonal ice. But as a recent NASA-supported study notes, current carbon sink estimates are limited because “harsh conditions there make collecting good data difficult.” So, little of the seabed has been studied and much remains unknown. By probing its deep reaches, Lagger and his team, who are based at the National Scientific and Technical Research Council of Argentina, hope to discover new species and update carbon storage estimates.
The team members collected samples from seven dives to the seabed during a three-week voyage as part of the National Geographic and Rolex Perpetual Planet Ocean Expeditions, a project sending researchers to study the Earth’s oceans. They deployed SuBastian’s mechanical arms to gather filter feeders to help identify new species and core samples from the ocean floor to analyze how much carbon they absorb. The team also brought back video of the terrain.
Several of these dives reached depths of more than 2,000 feet, and one descended nearly 13,000 feet—one of the deepest ROV dives ever recorded in the Southern Ocean—offering a unique perspective into the ecology of the seafloor, or benthic zone. As shallower waters and the land are gripped by the effects of climate change, deeper environments have stayed relatively pristine, Lagger explains. There, temperatures have likely been stable for centuries, and the ocean bottom has been mostly undisturbed. It’s “like a time machine,” Lagger says, “as if we can see what [marine] communities were like hundreds of years ago.”
The dives provided a rare opportunity to create a baseline of deep-sea health, so scientists can detect early signs of change in the future. Today the team is processing samples and examining some 40 hours of video footage to gain a better understanding of ecosystems at various depths on the ocean floor.
Lagger, who is also a director of the conservation foundation Por el Mar, believes data from this expedition will strengthen the case for designating more marine protected areas around Antarctica. It “is not only about preserving unique and largely pristine ecosystems,” he explains, “but about safeguarding ... the health of the Southern Ocean and its role in Earth’s systems.” As he points out: “What happens at the frozen edge does not stay there.”
