A fisherman’s routine shark-fishing trip off the coast of southern Australia turned into a scene from a marine thriller this morning when Trapman Bermagui — known online as Jason — hauled up the massive severed head of a mako shark weighing approximately 100kg.
The discovery has sparked intense speculation about what kind of predator is powerful enough to consume the body of such a formidable shark and leave only its head behind.
Jason, operating in waters near Bermagui, a coastal town in New South Wales, was targeting sharks when his line brought up the enormous mako head instead of a full catch. Posting on Facebook alongside an image of the head beside a young man for scale, he wrote: “So this was all we got back of this monster mako. Unfortunately we didn’t see what ate it but must of been impressive!! The head was about 100kg.”
He added: “It was a crazy morning of shark fishing. Hoping to catch smaller sharks but just hooked big sharks that got eaten by bigger sharks again.”
The Speed Demon of the Ocean
Mako sharks (Isurus oxyrinchus) are among the ocean’s most impressive predators. They can reach lengths of up to 3.8 metres (12 feet) and weights of 570kg (1,260 lbs). Renowned as the fastest sharks in the sea, they are capable of bursts of speed up to 46 mph (74 km/h), thanks to their streamlined bodies and powerful tails.
Jason posted this to his Facebook page about the unusual findingCredit: Facebook
Greg suspects it was more than one great white
Aaron agrees that more than one shark launched the attack
Shamus reckons it was a tiger shark
A mako of the size indicated by its 100kg head would represent a substantial meal — one that could only be taken by a significantly larger and more dominant predator.
Theories Emerge: Megalodon, Great Whites, or Orcas?
The find has naturally prompted questions about what creature could be responsible. While the extinct megalodon — a colossal shark that reached lengths of around 18 metres (58 feet) and dominated the oceans until roughly 3.6 million years ago — has been mentioned in excited speculation, most observers are focusing on currently existing species.
A large great white shark, which can grow to 6.1 metres (20 feet), stands out as a leading candidate. On Jason’s Facebook post, several commenters offered detailed analysis based on the bite marks visible on the head.
Greg Doble suggested the work of multiple great whites: “Great White more than one as well, you can see the smaller conveyor teeth outside major bite marks, not Orcas they tend to eat just the liver of large sharks and let the rest drop to the ocean floor.”
Aaron Smith concurred, writing: “Looks like it been hit by two sharks to me.”
Others proposed different culprits. Shamus Johnston believed a big tiger shark was responsible, while Damien leaned toward an orca, stating: “Doubt it was a shark that ate it, probably an orca.”
Orcas are known to hunt large sharks strategically, sometimes targeting nutrient-rich organs like the liver, though opinions differ on whether they would leave such a substantial head behind intact.
A Sign of Healthy — or Concerning — Waters?
While the incident highlights the brutal realities of the marine food chain, it also underscores the rich biodiversity off Australia’s southeastern coast. Encounters like this serve as dramatic reminders of the presence of apex predators and the complex interactions within the ocean ecosystem.
Jason and fellow fishermen continue to process the morning’s events, hoping for answers — or perhaps another encounter — on future trips. For now, the identity of the “monster” that devoured the mako remains a mystery lurking beneath the waves.
As one local observer noted, whatever was capable of taking down a large mako so cleanly must itself be an impressive force in these waters.
This story is developing as marine experts and the fishing community weigh in on the evidence.