There are no Sharks in Antarctica! The Discovery that Rewrote Polar Ocean Science

In early 2025, scientists revealed one of the most surprising polar discoveries in recent decades: the first confirmed shark ever recorded in Antarctic waters. Captured on deep-sea camera footage nearly 500 metres below the surface, the sighting challenges long-held assumptions about life in the coldest ocean on Earth and highlights how little we still know about the deep Southern Ocean.

The shark was filmed near the South Shetland Islands, off the Antarctic Peninsula, by researchers from the Minderoo–University of Western Australia Deep-Sea Research Centre. The footage, recorded in January 2025 and released publicly this season, shows a large sleeper shark slowly cruising across the seabed in near-freezing water at around 1.27°C. The animal was estimated to be between three and four metres long, making it a formidable deep-sea predator in an environment once thought inhospitable to sharks.

For decades, marine biologists believed that the extreme cold, isolation, and oceanographic barriers of the Southern Ocean prevented sharks from inhabiting Antarctic waters. The discovery, therefore, overturns a long-standing rule of thumb in polar marine science.

The shark belongs to the sleeper shark family (Somniosidae), a group of slow-moving, deep-water sharks known for their resilience in cold environments. The exact species has not yet been confirmed, though researchers suspect it could be a Southern sleeper shark, a poorly understood species previously recorded only in sub-Antarctic waters. DNA analysis from water samples is expected to provide further clarity.

Sleeper sharks are among the ocean’s most enigmatic predators. Their relatives include the Greenland shark, one of the longest-lived vertebrates on Earth, with some individuals estimated to be centuries old. These sharks typically inhabit deep, dark waters and feed on a range of prey, including fish, squid, and carrion, making them important scavengers and predators in deep-sea ecosystems.

Antarctica is one of the coldest marine environments on the planet, with surface waters often below freezing and deep waters only slightly warmer. Until now, only a handful of shark species had been recorded in the wider Southern Ocean, and none within Antarctic waters themselves.

The discovery suggests that sharks may have been present all along but remained undetected due to the remoteness of the region and the limited deployment of deep-sea cameras. Researchers believe the shark was filmed in a layer of relatively warmer water, sandwiched between colder surface meltwater and deeper, denser layers, creating a narrow habitable zone in the Antarctic Ocean.

The sighting has raised an intriguing question: are sharks expanding their range as oceans warm, or have they always been part of the Antarctic ecosystem?

Scientists caution that it is too early to attribute the discovery to climate change. The rarity of deep-sea observations means many species could exist undetected. However, warming oceans and shifting currents could alter species distributions in the future, making continued monitoring essential.

Beyond the shark itself, the discovery underscores how unexplored the deep ocean remains. The deep sea is one of Earth’s least-studied environments, particularly in polar regions, where research windows are limited to a short summer season.

Each new camera deployment reveals unexpected species and behaviours, reshaping our understanding of marine ecosystems. The Antarctic sleeper shark is a reminder that, even in the 21st century, major discoveries still await in the planet’s most remote corners.

For polar scientists, the finding provides new insights into food webs, biodiversity, and ecosystem resilience in extreme environments. Sharks are apex or mesopredators, and their presence could indicate more complex Antarctic deep-sea ecosystems than previously recognised. That said, the greatest predator of all in Antarctic waters is the orca. 

For expedition travellers and the wider public, the story reinforces Antarctica’s reputation as the last great frontier. While iconic wildlife such as penguins and cetaceans capture attention, the hidden world beneath the ice is equally extraordinary, and still largely unknown.

Researchers plan further deep-sea surveys, genetic testing, and long-term monitoring to determine how widespread sleeper sharks are in Antarctic waters and what role they play in the ecosystem. The discovery may also inspire new technological innovations in deep-sea exploration, as scientists seek to observe life in one of the harshest environments on Earth.

The first confirmed shark in Antarctica is more than a curiosity; it is a scientific milestone that reshapes our understanding of polar oceans. It challenges assumptions, opens new research questions, and reminds us that even in a world of satellites and supercomputers, nature still holds profound secrets beneath the ice.