Deep-sea explorers film massive animal drifting through darkness in South Atlantic Ocean

by isenews 4 February 2026 0 Comment

Scientists from the Schmidt Ocean Institute have uncovered an array of remarkable finds off the coast of Argentina, including the world’s largest known Bathelia candida coral reef, 28 new animal species and the country’s first deep-water whale fall – a whale carcass that sinks to the ocean floor.

Using a remotely operated vehicle known as ROV SuBastian, the team also stumbled upon a rare giant phantom jelly (Stygiomedusa gigantea). These titans of the deep ocean have four long arms that can grow up to 10 metres long – that’s as long as a school bus – while their bell can reach up to 1 metre in diameter.

“We were not expecting to see this level of biodiversity in the Argentine deep sea and are so excited to see it teeming with life,” says the expedition’s chief scientist, María Emilia Bravo.

“Seeing all the biodiversity, ecosystem functions, and connectivity unfolding together was incredible. We opened a window into our country’s biodiversity only to find there are so many more windows left to be opened.”

Whale fall recorded at a depth of 3,890 metres. These dead animals serve as temporary ecosystems and a food source for animals such as octopuses, sharks and crabs. Credit: ROV SuBastian | Schmidt Ocean Institute

The team’s research area spanned the length of Argentina’s coast, from Buenos Aires in the north to Tierra del Fuego in the south. Their main goal was to find cold seeps – deep-sea environments where methane and other chemicals are released from the seafloor.

Cold seeps provide energy for microbes, which in turn are a source of food and nutrition for animals such as tube worms, mussels and clams. The team located one huge seep, which was almost the size of the Vatican City.

Glass squid — ROV pilots filmed this glass squid at 1,725 metres while exploring the Colorado-Rawson submarine canyon off the coast of Argentina. Credit: ROV SuBastian | Schmidt Ocean Institute

Another notable find was a vast coral reef made up of a stony cold-water coral known as Bathelia candida, which provides important habitat for fish, crustaceans and octopuses. Bathelia has been recorded throughout the Southwestern Atlantic Ocean, however, the reefs found during this latest expedition extend its range 600 kilometres (373 miles) further south than was previously known.

At the bottom of the 3,000-metre-deep Malvinas Trough, off the coast of Tierra del Fuego, the researchers observed large sponges sheltering bubblegum coral gardens (Paragorgia arborea) – the branch tips of these ancient white, red or salmon-coloured corals are bulbous, giving them their bubblegum name.

Bubblegum corals filmed by ROV pilots at a depth of 500 metres on the southern flank of the Malvinas Trench. These corals grow at a rate of approximately 1 centimetre a year. As colonies exceed 1 metre in height, it indicates that they are likely to be hundreds of years old. Credit: ROV SuBastian | Schmidt Ocean Institute

“We collected an unprecedented number of chemical, physical and biological samples that will be used to understand connections in our waters for years to come,” says researcher Melisa Fernández Severini.

“These samples represent a unique opportunity to understand not only how extraordinary these extreme ecosystems are, but also how vulnerable they can be.”

Schmidt Ocean Institute’s executive director, Jyotika Virmani, says, “With every expedition to the deep sea, we find the ocean is full of life – as much as we see on land, and perhaps more because the ocean contains 98% of the living space on this planet.

“We have been privileged to work with outstanding scientists across three expeditions in Argentinian waters and look forward to seeing their research continue to unfold, unlocking new understanding and inspiration.”