A team of deep-sea researchers captured video of a sleeper shark prowling nearly 500 meters below the surface near Antarctica’s South Shetland Islands in January 2025, marking the first time the elusive species has been filmed in the continent’s near-freezing depths. The shark, estimated at 3 to 4 meters long, was recorded in water chilled to 1.27 degrees Celsius by a baited camera system deployed by the Minderoo-UWA Deep-Sea Research Centre. The footage has forced marine biologists to reconsider long-held assumptions about which large predators can survive in these extreme polar waters, and it raises pressing questions about what other giant sharks or shark-like predators may be lurking in zones that remain almost entirely unexplored.
First Camera Proof From Antarctic Depths
For decades, scientists have suspected that sleeper sharks, close relatives of the Greenland shark, inhabit the deep Southern Ocean. But direct visual evidence from below the Antarctic Convergence has been vanishingly rare. That changed when researchers lowered a baited camera to roughly 490 m near the South Shetland Islands and recorded a large, slow-moving shark estimated at 3 to 4 meters, or about 10 to 13 feet, in length. The water temperature at that depth registered 1.27 degrees Celsius, cold enough to deter most large marine predators and well within the range that researchers had previously considered inhospitable for sharks of this size.
The Minderoo-UWA Deep-Sea Research Centre, a joint initiative between the Minderoo Foundation and the University of Western Australia, deployed the equipment. The same research group had already demonstrated its baited-camera methodology during a separate 2025 expedition to the Tonga Trench, where it also documented sleeper sharks at extreme depths. That prior work established the instrumentation protocols, including paired depth and temperature sensors, that made the Antarctic capture possible. The consistency of the method across two very different ocean environments lends weight to the reliability of the measurements recorded near the South Shetland Islands.
A Shark That May Not Be Its Own Species
The excitement around the footage runs into a taxonomic complication that most coverage has glossed over. A peer-reviewed study published in the Journal of Heredity used RADseq phylogenomic and population-genomics analyses to examine the genetic relationships among sleeper sharks in the subgenus Somniosus. The researchers found that two S. antarcticus samples were intermixed within the S. pacificus clade, meaning the DNA of the so-called Antarctic sleeper shark was indistinguishable from that of the Pacific sleeper shark at the genomic level. The study’s authors concluded that their results provided the strongest molecular support to date for treating S. antarcticus as a synonym of S. pacificus rather than a distinct species.
If that synonymy holds up under further sampling, the narrative shifts considerably. Rather than discovering a rare, range-restricted Antarctic predator, scientists may instead be documenting the southern reach of a species already known to range across the Pacific basin. That distinction matters for conservation planning. A species with a broad geographic footprint faces different population-level risks than one confined to a single polar region, and management bodies would have to consider genetic connectivity rather than isolated stocks. The limited sample size of just two S. antarcticus specimens in the genetic study means the question is not fully settled, but the direction of the evidence is clear. The shark filmed near the South Shetland Islands likely belongs to a far more widespread lineage than its name suggests.
Why Deep Antarctic Waters Stay So Poorly Mapped
The rarity of this footage reflects a broader gap in ocean science. Waters south of 60 degrees south latitude fall under the Antarctic Treaty System, which imposes strict environmental protocols on any research activity. Deploying heavy equipment like baited camera rigs requires logistical coordination that few institutions can manage, and the window for safe operations in the Southern Ocean is narrow, typically limited to the austral summer months of December through February. Ice coverage, extreme weather, and the sheer distance from supply ports all compress the time available for deep-water surveys and make repeat observations difficult.
As a result, the deep benthos around Antarctica is one of the least-observed marine environments on Earth. Most knowledge of what lives below 400 meters in these waters comes from incidental bycatch in fishing operations or from rare trawl surveys, not from direct observation. The Minderoo-UWA team’s success with baited cameras offers a replicable, relatively low-impact method for filling that gap, because stationary cameras can operate without the sweeping disturbance of a trawl net. But scaling it up would require sustained funding and repeated deployments across multiple seasons and regions, something no single expedition can accomplish. The January 2025 footage is a data point, not a baseline, and treating it as proof of a stable shark population in these depths would outrun the evidence that currently exists.
What a Warming Ocean Could Mean for Polar Predators
One hypothesis that the sighting invites, though the available data cannot yet confirm, is that warming currents may be expanding the habitable range for large deep-sea predators in Antarctic waters. The Southern Ocean is warming at measurable rates in many layers, and even small temperature shifts at depth can alter the distribution of prey species like squid and toothfish that sleeper sharks are known to feed on in other regions. If prey populations shift poleward or deeper in response to changing water masses, predators capable of tolerating near-freezing conditions could follow, potentially turning what was once a marginal habitat into a regular hunting ground.
That scenario carries real ecological stakes. Antarctic benthic ecosystems have evolved in relative isolation from intense shark predation, and many resident fishes and invertebrates are slow-growing and highly specialized. Introducing or increasing the presence of a top predator, even a slow-moving one like a sleeper shark, could alter food-web dynamics in ways that ripple through krill, fish, and invertebrate populations. The rare video from Antarctica has drawn global attention to this possibility, but the harder scientific work lies ahead (determining whether this shark was a transient visitor or part of a resident population, and whether its presence is new or simply newly detected). Without long-term monitoring arrays in place, that distinction will remain unresolved, and any link to climate-driven change will be speculative rather than demonstrated.
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*This article was researched with the help of AI, with human editors creating the final content.
