Massive Shark-Eating Creature is Still at Large

Last week, I wrote about the mysterious creature off the coast of Australia that had gobbled up a nine-foot great white shark.

https://www.youtube.com/watch?v=Z_QyGANCUJI

The gruesome story of Shark Alpha will be told in the Smithsonian's upcoming Hunt for the Super Predator documentary, which will most likely conclude by suggesting that a larger great white shark could have done the deed. This prompted several national science blogs—which had gotten wind of the video and brought it to my attention—to declare the mystery solved. NBC News published an especially skeptical take on the story, which I'm inclined to sum up as "grumble grumble grumble, it was obviously a shark, why do you consider this newsworthy, you're not even scientists, grumble grumble grumble." And that's a perfectly valid point of view, especially if you believe science is something about which the general public should have little knowledge or interest.

But for those of you who believe "best explanation I've heard so far" and "only explanation I'm willing to entertain" are not necessarily the same thing, I'm pleased to report that my friend Bruce Morgan Jr., an independent scholar, contacted Dave Riggs—who collected this information in the first place—and discovered some interesting facts:

• The tag, though secure, was external. My previous belief that the predator couldn't have been a great white shark was based on what I believe to be an animation error from the clip shown above, which seemed to show a consistent 46°F pre-gobbling, regardless of depth. As it happens, the tag was not embedded in the shark's muscle tissue. Since 46°F was the actual water temperature, a 78°F belly temperature for a great white shark implies a 32°F difference between the predator's internal temperature and the water—more than the 25°F maximum most sources predict for a great white shark, but within the realm of possibility.
• There were "erratic temperature readings just prior to the tag's ingestion." This also didn't show up in the animation, and it might add layers to our story.
• There's a "known hydrocarbon seep" beneath Alpha Shark's final known location, with "an enormous aggregation of marine species" nearby. If you went looking for a location where a giant shark-eating critter might plausibly be, this would be on the list.

So was this very large great white shark eaten by an even larger great white shark? As far as some people are concerned, the answer is an easy yes. As far as I'm concerned, the jury's out; until I see a stronger case that the culprit was a great white shark (and the Smithsonian documentary may help provide one), I'm not inclined to compress this ellipse into a period.

Think this is an open-and-shut case? Have your own theories as to what might have eaten the shark? You can share your thoughts below.