Four months after filmmaker Dave Riggs and a research team tagged a 9-foot (3-meter) female great white shark off Australia’s coast, the animal vanished. The tracking tag turned up— it recorded the animal’s position, depth in the water, and the ambient water temperature as if nothing had happened. Riggs found it two and a half miles from where the large female was first tagged, but without the shark attached. What happened to her? According to a recent documentary that premiered on the Smithsonian Channel last week, she was eaten.
The female great white disappeared in 2003, and in the intervening 11 years researchers have been speculating as to what could have eaten such a large ocean predator. The smoking gun evidence of predation was a peculiar temperature change that the tag recorded all those years ago. Data from the large female initially looked normal, with the shark descending and the tag recording the surrounding water temperature. Then, at around 2,000 feet (610 meters) below the surface, the recorded temperature increased dramatically from 46°F to 78°F (7°C to 25°C). A temperature at that depth could only come from the tag being inside another animal, an animal big enough to kill and eat a 9-foot great white shark.
In the Smithsonian documentary that aired on June 25th, Riggs and a team of researchers concluded that it was probably another great white that devoured their tagged female. “The internal temperature of the animal that ate the shark is a weird one. It appears to be too low for a killer whale and too high for another shark, unless it was massive,” Riggs explained. If it was another great white, Riggs speculates, it would have to be huge.
To be clear, the researchers don’t know for sure what caused the huge temperature shift their tag recorded, and an unusually massive great white is only one possible answer, not necessarily the correct one. Some researchers think it is more likely that an orca—orcas are known to kill and eat great whites—ingested chilled seawater along with the tag to produce the data that astounded Riggs. Additionally, cannibalism is common among great whites, but that predation most often occurs before birth in a shark-eat-shark womb war zone. Even so, as the majority of great white sharks recorded have been much larger than the disappeared female, the simplest answer could be a great white attack. The mystery of the vanished great white is still informed speculation at this point.
“The big shark scenario is the theory that is most widely accepted although I’ve noticed a lot of other creatures being suggested online–I don’t think that Godzilla is a possibility though!”
You can watch the viral teaser for the documentary below:
Kyle Hill is the Science Editor of Nerdist Industries. Follow the continued geekery on Twitter @Sci_Phile.