An unexpected sight has challenged long-held scientific assumptions about marine life in Antarctica, after a substantial sleeper shark was filmed in the region’s frigid depths.
The creature, described as an “ungainly barrel” of a shark, was captured on video in January 2025, cruising languidly over a barren seabed far beyond the reach of sunlight.
Researcher Alan Jamieson revealed this week that many experts had previously believed sharks did not inhabit the icy Antarctic waters.
The specimen, estimated to measure between 3 and 4 metres (10 and 13 feet), represents a significant discovery, overturning prior understanding of the area’s biodiversity.
“We went down there not expecting to see sharks because there’s a general rule of thumb that you don’t get sharks in Antarctica,” Jamieson said.
“And it’s not even a little one either. It’s a hunk of a shark. These things are tanks,” he added.
The camera operated by the Minderoo-UWA Deep-Sea Research Centre, which investigates life in the deepest parts of the world’s oceans, was positioned off the South Shetland Islands near the Antarctic Peninsula. That is well inside the boundaries of the Antarctic Ocean, also known as the Southern Ocean, which is defined as below the 60-degree south latitude line.
The center on Wednesday gave The Associated Press permission to publish the images.
The shark was 490 meters (1,608 feet) deep where the water temperature was a near-freezing 1.27 degrees Celsius (34.29 degrees Fahrenheit).
A skate appears in frame motionless on the seabed and seemingly unperturbed by the passing shark. The skate, a shark relative that looks like a stingray, was no surprise since scientists already knew their range extended that far south.
Jamieson, who is the founding director of the University of Western Australia-based research center, said he could find no record of another shark found in the Antarctic Ocean.
Peter Kyne, a Charles Darwin University conservation biologist independent of the research center, agreed that a shark had never before been recorded so far south.
Climate change and warming oceans could potentially be driving sharks to the Southern Hemisphere’s colder waters, but there was limited data on range changes near Antarctica because of the region’s remoteness, Kyne said.
The slow-moving sleeper sharks could have long been in Antarctica without anyone noticing, he said.
“This is great. The shark was in the right place, the camera was in the right place and they got this great footage,” Kyne said. “It’s quite significant.”
The sleeper shark population in the Antarctic Ocean was likely sparse and difficult for humans to detect, Jamieson said.
The photographed shark was maintaining a depth of around 500 meters (1,640 feet) along a seabed that sloped into much deeper water. The shark maintained that depth because that was the warmest layer of several water layers stacked upon each other to the surface, Jamieson said.
The Antarctic Ocean is heavily layered, or stratified, to a depth of around 1,000 meters (3,280 feet) because of conflicting properties including colder, denser water from below not readily mixing with fresh water running off melting ice from above.
Jamieson expects other Antarctic sharks live at the same depth, feeding on the carcasses of whales, giant squids and other marine creatures that die and sink to the bottom.
There are few research cameras positioned at that specific depth in Antarctic waters. Those that are can only operate during the Southern Hemisphere summer months, from December through February.
“The other 75% of the year, no one’s looking at all. And so this is why, I think, we occasionally come across these surprises,” Jamieson said.
