What Did Scientists Find in the Mar del Plata Submarine Canyon?

Forty Potential New Species in a Single Canyon Dive

During a live-streamed ROV expedition into the Mar del Plata submarine canyon off Argentina’s coast, scientists discovered approximately forty organisms that appear to be entirely unknown to science — including red soft corals and star-shaped animals found along the continental slope.

What Is the Mar del Plata Submarine Canyon?

The Mar del Plata submarine canyon is a deep underwater valley carved into Argentina’s continental shelf in the South Atlantic Ocean. Despite sitting off one of South America’s most populated coastlines, it remained largely unexplored by science before this expedition. The canyon descends into darkness along a stretch of continental slope where deep-sea life had never been systematically surveyed.

Why Is This Canyon So Biologically Rich?

The canyon sits at one of the most productive oceanographic collision zones in the entire South Atlantic. The cold Malvinas Current sweeps northward from Antarctic waters, while the warm Brazil Current pushes southward from the tropics. Where these two currents meet directly above the canyon, nutrients are churned upward and food particles are suspended in the water column — creating conditions that support an extraordinary density of deep-sea life. Scientists believe this current collision is directly responsible for the canyon’s unusual biodiversity.

What Species Were Found?

Among the candidate new species recorded during the expedition were red soft corals thriving in complete darkness and star-shaped animals clinging to the canyon’s rocky slope. Deep-sea soft corals require no sunlight — they feed entirely on organic particles carried by deep currents, surviving in cold, high-pressure environments that appear hostile but are in fact richly supplied with food. The star-shaped organisms, whose exact classification is still under review, add to a growing list of animals that defy expectations about where complex life can exist.

How Was the Discovery Broadcast Live?

The expedition was conducted by the Schmidt Ocean Institute, which streamed raw ROV footage in real time directly to the public on YouTube and Twitch. There was no editing, no delay, and no filter — viewers around the world watched the robot arm sweep past unnamed creatures at the same moment scientists did. This kind of live broadcast is rare in deep-sea science, and it allowed the public to witness the moment of discovery as it happened.

Why Does This Matter for Ocean Science?

Scientists estimate that more than ninety percent of deep-sea species worldwide have never been formally described by science. That figure makes the ocean floor — despite being Earth’s largest habitat — effectively invisible to biology as a discipline. The Mar del Plata canyon findings underscore how little exploration has occurred even in relatively accessible regions close to major population centers. Each new species found here adds pressure to accelerate deep-sea surveys before ocean warming, acidification, and potential deep-sea mining alter these ecosystems permanently.

What Happens After a Potential New Species Is Found?

Spotting an unfamiliar organism on ROV footage is only the first step. Specimens must be collected, preserved, and analyzed genetically and morphologically before a species can be formally described and named in a peer-reviewed journal. That process can take years. The forty organisms recorded in this expedition are considered candidate new species — meaning they appear to be new to science, but confirmation requires further study.