Vatican-Sized Coral Reef and Ghost Jellyfish — Schmidt Ocean Institute Reveals Argentina's Deep-Sea Biodiversity

From Vatican-Sized Coral Reefs to Ghost Jellyfish — The Wonders of Argentina's Deep Sea

Argentina's deep sea proved to be far richer in life than scientists had imagined. An Argentine-led research team aboard Schmidt Ocean Institute's R/V Falkor (too) explored the remote waters of the Argentine Basin, discovering ecosystems of astonishing diversity across four expedition legs.

Discovery of the World's Largest Bathelia Coral Reef

The Bathelia candida coral reef discovered on this expedition spans at least 0.4 square kilometers — roughly the size of Vatican City. Even more remarkably, this reef was found 600 km south of the species' previously known range, suggesting potential shifts in deep-sea coral distribution.

A Whale Graveyard at 3,890m Depth

On the Salado-Colorado Kilometer Escarpment in the Argentine Basin, the remains of a whale were found resting on the seafloor at 3,890 meters. This is the first whale fall ever recorded in Argentine waters — a 'deep-sea oasis' that sustains unique ecosystems for decades as lipids in the bones slowly decompose.

Giant Ghost Jellyfish and Cold Seep Ecosystems

At 250 meters depth, the rare giant phantom jellyfish (Stygiomedusa gigantea) was filmed. With an umbrella diameter up to 1 meter and four arms reaching up to 10 meters, it ranks among the largest jellyfish in the world.

A vast active cold seep spanning 1 square kilometer was also discovered. Large colonies of chemosynthetic clams (Archivesica and Calyptogena) thrive here, supported by chemical energy from methane and hydrogen sulfide seeping from the seafloor rather than sunlight.

Researcher's Perspective

We did not expect such biodiversity in Argentina's deep sea. Seeing it teeming with life was incredibly exciting.

— Dr. María Emilia Bravo (University of Buenos Aires / CONICET, Chief Scientist)

Every deep-sea expedition reveals that the ocean is full of life. As much as land, perhaps even more so — because the ocean represents 98% of Earth's habitable space.

— Dr. Jyotika Virmani (Executive Director, Schmidt Ocean Institute)

For more on cold seep ecosystems, see "38 New Species — JAMSTEC & Ocean Census."

What These Discoveries Mean

Coral range expansion 600km south — a climate change signal?

The discovery of Bathelia candida reefs 600 km south of their known range may reflect changes in ocean conditions. Shifts in deep-sea coral distribution could indicate changes in water temperature, chemistry, or current patterns driven by climate change.

Whale falls — recording the deep sea's first 'oasis'

Whale carcasses are oasis-like features in the deep-sea 'desert.' The lipids in bones decompose over decades, forming unique ecosystems around them. This first record from the Argentine Basin opens new research opportunities into these remarkable deep-sea communities.

Cold seep discovery — a treasure trove of chemosynthetic ecosystems

The discovery of a 1-square-kilometer cold seep reveals active geological processes beneath the Argentine seafloor. Ecosystems dependent on chemosynthesis — life sustained without sunlight — demonstrate the remarkable adaptability of deep-sea life.