Eleven years ago, a mystery sea creature devoured a 9-foot great white shark in Australia's Southern Ocean. Now researchers have returned to the scene of the incident to determine what killed the apex predator.
That's the subject of an upcoming documentary from the Smithsonian Channel, "The Hunt for the Super Predator," which was inspired by an earlier documentary from the Australian Broadcasting Corp. called "The Search for the Ocean's Super Predator,"Gizmodo reported.
Cinematographer David Riggs remembers the day the healthy female shark was tagged as part of a project to study the species' movement patterns along Australia's coastline.
"She came in with a real swagger," Riggs says in the documentary. The shark, nicknamed Shark Alpha, swam away "without any signs of distress."
Four months later, Shark Alphas's tag washed ashore. The tag was found by a beachgoer about two and half miles from where the device was attached, according to the video.
Data recorded on the tag revealed that Shark Alpha plunged to a depth of 1,900 feet right before the device showed a sudden temperature rise from 46 to 78 degrees Fahrenheit. It remained at that temperature for eight days before the tag came ashore.
Researchers believe that the rapid temperature shift could only happen if the tag was inside the stomach of another animal, indicating that the shark was attacked by a larger creature, possibly a bigger great white.
Researchers can't be sure what prompted the shark-on-shark attack but suggest that it could have been a territorial dispute or the larger shark was just really hungry.
There have been previous instances of great white shark cannibalism. In 2009, for example, a 20-foot-long shark took a bite out of a smaller great white shark along the Queensland coast.
"That cannibal thing is what great whites do. They'll eat anything, including their own kind," shark expert Hugh Edwards told Channel 7 News in Australia.
Watch a clip from the documentary, courtesy of the Smithsonian YouTube channel.
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