MELBOURNE, Australia — An unexpected sight has emerged from the depths of the Antarctic Ocean: a sleeper shark, known for its sluggish movement, was filmed swimming over a lifeless seabed during a recent research expedition. Experts were surprised by this finding, given the prevailing notion that sharks are rarely found in the frigid waters surrounding Antarctica.
The shark, captured on video in January 2025, was estimated to measure between 3 and 4 meters (about 10 to 13 feet) in length. “We approached our research expecting not to encounter any sharks, as it is commonly believed that these species do not inhabit Antarctic waters,” said Alan Jamieson, the founding director of the University of Western Australia’s research center. “What we found was impressive; it’s a substantial animal—it’s quite literally a tank in the ocean.”
The camera used to document this sighting was deployed by the Minderoo-UWA Deep-Sea Research Centre, which focuses on exploring life in the ocean’s darkest depths. Positioned near the South Shetland Islands, the research team captured footage at a depth of 490 meters (1,608 feet), where the temperature hovered just above freezing at 1.27 degrees Celsius (34.29 degrees Fahrenheit).
Interestingly, a skate—an oceanic relative of the shark resembling a stingray—was recorded alongside the sleeper shark, contributing to the growing body of knowledge about marine life in this remote region. While the presence of the skate was anticipated, the sighting of the sleeper shark marked a potential re-evaluation of marine biodiversity in Antarctic waters.
Jamieson stated that he could not find any documented evidence of sharks previously spotted in these depths. Peter Kyne, a conservation biologist at Charles Darwin University, echoed this sentiment, noting that this sighting represented a significant breakthrough in understanding the geographic range of shark species.
Kyne suggested that climate change and rising sea temperatures could be altering the habitats available to sharks, pushing them further south into cooler waters. However, due to the region’s inaccessibility and the limited data available, further exploration is necessary to understand these shifts fully.
The slow-moving sleeper shark may have existed unnoticed in these waters for quite some time, according to Kyne. “It’s fortunate that we had the right timing and equipment to capture this footage,” he said. “This emphasizes the significance of our research efforts in such remote locations.”
Jamieson indicated that the sleeper shark appears to thrive at the depth where it was filmed. This layer, strategically positioned between colder, denser waters below and melting freshwater above, provides an environment conducive to the survival of such large marine creatures.
Despite being a notable discovery, researchers face challenges in studying these depths due to their harsh conditions. Research equipment often operates only during the Southern Hemisphere summer, from December to February. “For the other nine months of the year, there is a substantial gap in our monitoring efforts,” Jamieson noted. “This seems to result in occasional surprises in marine biology.”
As research continues, scientists hope to uncover more about the elusive sleeper shark population and the broader marine ecosystem in the Antarctic, paving the way for increased understanding of how species adapt to extreme environments.