Scientists have documented the largest known reef built by the white hard coral Bathelia candida and nearly thirty previously unrecognized animals along Argentina’s deep Atlantic margin.
Those discoveries change what scientists thought they knew about this coastline and reveal deep-sea ecosystems far more complex than earlier surveys had shown.
Reefs off Argentina’s coast
High-definition video from the remotely operated vehicle SuBastian streamed back from the research vessel Falkor (too) as it explored Argentina’s continental slope, capturing dense coral structures and unfamiliar creatures across the seafloor.
Guiding the mission, Dr. Maria Emilia Bravo at the University of Buenos Aires chose dive targets as those images revealed the reef’s true scale and the breadth of life surrounding it.
Footage confirmed that the coral structure stretched farther and hosted more species than earlier surveys had recorded.
That visual record set the stage for closer examination of what this reef is, how far it extends, and why its reach matters.
A record coral reef
Across one stretch of seafloor, the coral reef covered at least 0.15 square miles, close to Vatican City in size.
Built by the stony coral Bathelia candida, the hard skeleton held in place animals that need shelter from currents.
Managers often treat such reefs as Vulnerable Marine Ecosystems, meaning slow growers recover poorly after heavy gear scrapes the bottom.
Farther south, pilots recorded similar reef patches about 373 miles beyond earlier maps, widening where protection rules may apply.
Cold seeps feed life
Chemical-rich cold seeps, deep seafloor leaks that fuel microbe-based food webs, were a main target during the voyage.
Methane and other compounds seep upward, and microbes turn that chemistry into food that clams and tube worms can eat.
A 2024 paper by Bravo and colleagues described Argentina’s first confirmed deep-sea seeps, showing mixed diets in nearby animals.
Finding one active seep spanning about 0.39 square miles raised new questions about how seep life links with nearby coral habitats.
A whale becomes habitat
At about 2.4 miles depth, the cameras filmed Argentina’s first deep-water whale fall, a whale body resting on the seafloor.
Scavengers strip soft tissue first, then microbes break down fats and release sulfide that feeds specialized bacteria.
A 2003 review laid out how whale remains can support changing communities for decades, even in food-poor basins.
Once most flesh is gone, the bones turn into hard real estate that small animals can use for years.
The ghost jelly appears
Near 820 feet underwater, the robot filmed a giant phantom jellyfish drifting past, with juvenile fish sheltering around its bell.
Instead of hunting with stinging tentacles, the animal sweeps four long mouth arms through the water and traps prey.
A profile from the Monterey Bay Aquarium Research Institute says those arms can reach about 33 feet.
That brief encounter also showed why cameras matter, since many deep-sea giants stay nearly invisible until robots pass by.
Samples link ecosystems
Back on deck, crew members stored jars of mud, coral fragments, and small animals from different depths along the shelf.
Chemical fingerprints in those samples can reveal whether food started as plankton from sunlight or microbes fed by seep gases.
Matching species and chemistry across sites helped UBA scientists test how larvae and nutrients traveled between reefs, seeps, and open water.
Those links can explain why one protected patch may not survive if nearby areas lose the connections that restock it.
Trash reaches the abyss
Plastic fishing nets, garbage bags, and even an old videotape turned up on the seafloor during several runs.
Cold, dark water slows decay, so plastics and lost gear can sit for years with little change.
A Korean sticker on the tape left the team unsure how far the trash had traveled before sinking.
Seeing human waste beside fragile habitats set a hard limit on what exploration can celebrate without also tracking pollution.
Rules lag behind reality
Maps of reefs and seeps land in a world of fishing quotas, shipping routes, and offshore drilling plans.
In their 2024 paper, Bravo’s UBA team noted that some seep areas overlap blocks offered for oil and gas exploration.
Clear evidence of dense animal communities gives regulators something concrete to avoid when they draw boundaries for industry and research.
Without those lines, slow-growing corals and seep species could take the hit long before anyone learns they exist.
Naming takes time
Finding a strange animal on camera does not automatically create a new species for science.
Taxonomists use taxonomy, the system for naming and classifying life, to compare specimens with every described relative.
Careful descriptions often require physical samples, since tiny differences in spines, shells, or genes can separate lookalikes.
Until experts publish those names, the animals stay hard to track, and protecting them becomes a guess.
Better maps of reefs, seeps, and food falls now give Argentina a clearer picture of what lives offshore.
As taxonomists and ecologists process the samples, these discoveries should guide where future gear, drilling, and science trips go.
Learn more about this mission and its discoveries here…
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