What is all this chatter about??? When a Doctoral Candidate from the Woods Hole National Oceanic Institute has said it was most likely a Killer Whale.....well, I'm betting with him!!
Photograph by Fred Bavendam, Minden/Corbis
Published June 13, 2014
Speculation that a great white shark that went missing off Australia may have been devoured by another great white is making the Internet rounds this week, raising the question of whether it was an instance of shark cannibalism.
The shark that disappeared was wearing a research tag, which a beachcomber found 2.5 miles (four kilometers) away from where it had been affixed to the shark.
The tag, initially attached in November 2003 off southwestern Australia, was set to record ambient temperatures and depth. Its data showed that four months after it was attached, the female great white abruptly dove to a depth of 1,903 feet (580 meters). The ambient temperature surrounding the tag spiked from 46°F to 78°F (8°C to 26°C). The data suggested an attack.
Filmmaker David Riggs, who'd been hired to document the tagging project that involved the nine-foot-long female shark, couldn't believe the data at first.
Clearly something ate the shark, Riggs said in a YouTube clip uploaded by the Smithsonian Channel a couple of weeks ago. A reddit user posted the video on the popular site this week, and it quickly went viral. But "what could kill a three-meter great white?" Riggs asked. (See "Scientists Track a Great White Shark Across the Atlantic for the First Time.")
The search for the perpetrator is the subject of a Smithsonian Channel show airing later this month.
Cannibalism Is Common
Experts say that speculation that a great white devoured the missing female great white is not outside the realm of possibility.
"Cannibalism in sharks is quite common in both juveniles and adults," said Camrin Braun, a doctoral student at the Woods Hole Oceanographic Institution in Massachusetts who studies shark population and behavior. White sharks in particular have highly variable diets, he added in an email interview, and are likely opportunistic when it comes to finding food.
But a more likely explanation for the surprising tagging data, said Braun, is that the female great white got caught in the crosshairs of a killer whale.
"White shark stomach temperatures are thought to be on the order of 65 to 70°F," he explained. "Maybe even less at great depth in cold water." That's cooler than the temperature recorded on the tag.
The only other animal that could take on a small great white—and that has a warmer ambient internal temperature—is the killer whale, Braun said. Their internal temperatures run about 90°F (32°C), he explained. "Thus, it seems likely that a feeding killer whale that is ingesting cold seawater and food could easily have a stomach temperature of 78°F."
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So tired of all the killing....orcas and great whites should both be tried in the International Criminal Court for war crimes...
It seems that with the sudden change in depth, the shark was probably trying to escape a predator, theoretically after an attack. An orca would probably kill the shark quickly, but given that the shark had time to dive to 1903 feet below, I would make the case for cannabalism.
So, this means that the Orca - or whatever - swallowed the tag as well (The headline says "whole"). Then, as the old song goes, what swallowed the Orca?
It's what occurred to me when "a beachcomber" found the tag. Not that it is suspicious, but is it common for tags to wash up on beaches? I don't know that much about tagging.
My guess is orca. They do prey on sharks and are about the only animal that can easily kill a great white. There is video footage of an orca killing a great white shark by merely flipping it upside down and then killing it. Scientists know that flipping a shark can immobilize it for data gathering purposes and return to habitat when done. Orcas have learned this trick, too. By flipping the shark, it can be easily killed with no harm done to the orca. Their superior intelligence and power make them the apex animal of the oceans. A great white shark cannot compete.
I'm betting on a Colossus Squid as the prime suspect with Orca being second choice; I believe a sperm whale may also have eaten the shark except for the fact they usually dive to great depths in search of food.
The depth of the dive and size of the dead shark lead me to believe that what we're talking about here is a sperm whale.
When I first read the news, first thing that came to mind was killer whales. I've seen a footage of a pack of killer whales attacking and eating a great white before. But the ocean is too vast to conclude such theory. It could've been eaten by something scientist never encounter before.
The same comments here that I've seen elsewhere about this article and I'm shocked that Nat Geo would also decide that something must have eaten the shark wearing the tag...but there is so far no proof the shark was eaten, only that the tag it was wearing was.
Here is an off the wall thought;
I think it is generally accepted that the depths of the ocean are still very much an unknown and that there may be many species that we do not know about. Still very much an unknown frontier.
Being in the midst of an apparent global climate change and the effect that is having on the oceans' temperatures and saline content, who knows what may be coming closer to surface, at this time unbeknownst? May be another Alpha predator is emerging.
Just as the eco system and wildlife is changing above ground, I imagine that the same is happening below. The world in it's entirety may be changing as we have come to know it.
We tend to explain things using the rationale of things we know and certainly in this case it may be so, then again...............
A single Orca that specializes in great white shark eating is more than enough to take out a great white of any size, no "pack" required. They take advantage of the fact that if you flip a shark upside down it will likely go into tonic immobility.
Probably an orca. If those things can take down other whales bigger than themselves, they could certainly take down a great white. My guess is that they ganged up on it. I'm not sure if they fight over a carcass like other animals or not, but I assume the whale who ingested the tag just happened to get that "cut" of the shark. It probably didn't notice the tag, as it might have been rushing to get as much of the shark as it could before the other members of its pod came.
maybe the killer whale ate it but the shark gived a fight and hurted and almost killed the whale when it ate it and it died really soon. when an animal die they loses its temperature and its in the cold waters so I think it will happen more quicker.
when fishing off a pier locally, i see sharks eat baby sharks frequently. I don't see why Whites would be any different then the Tigers or Black Tips that we usually see.
What do you call a killer whale? Would it be an Orca? These are not whales but dolphins.Will you solve my doubts?
Really, a couple of days after the scientists who placed the tag on the shark explained this whole story, you post this article?
I'd lay bets on the Orca. Its already common knowledge that some Orca's prey almost exclusively on great whites...... But wouldnt it be awesome to find a whole new undiscovered species of gigantic killer lurking in the depths!!! I can only hope.
It's to bad that the tag didn't have the ability to take photo's during very active times. Even an ir image would have helped, Or if it had the ability to track the salinity of it's surroundings. With a combination of temp and salinity it could have solved the question. Just a thought for future tags maybe!
Since the whole article is highly speculative, I'll just point out that the tagged shark would have survived if only someone had strapped a frikkin laser onto its head. Or maybe the shark didn't like the tag and had a friend pull it off :-)
What is the likelihood that a Cookie Cutter Shark happened to take a bite at the location of the tag? Based on the speed with which they bite and flee, it seems like a distinct possibility. All we seem to really know is that the tag ended up in a warm place, not the entire shark itself.
Sorry, the increase in ambient temperature indicates the tag was surrounded by warm fluids, those do not exist at those depths unless in the gut of a warm blooded predator. Therefore the suggestion of an Orca or Sperm whale attack.
@Andrew Ramos Yep, I've seen video footage of orcas doing exactly that! They have learned that by flipping a shark, immobilizing it, they can easily kill it without injuring themselves. There is also footage of them teaching this to their young. Incredible how amazingly intelligent and powerful orcas are!!
@Andrew Ramos Orcas generally do hunt great whites solo, they do so by swimming from below the shark and spearing the stomach causing the shark to implode, then the whale feasts on the shark.
@Douglas Gertsch This was my thought too, the temp and the fact that it varies in depth say mammal, I think a pod of Killer whales is more than capable of doing it.
@Leslie Fazakerley How would you explain the spike in temperature, unless something mistook it for food and swallowed it.
@Maria Malu theres much debate going on in the name. In the scientific community, Killer whale is the preferred name as what distinguishes this species "culture" is usually a hunting behaviour and preference for prey (ei transient vs mammal eating). In the public eye, orca is preferred as it removes the negative association of the "killer"
@Maria Malu Killer whales or orcas belong to the order of the Cetacea, meaning whales, there to the suborder of Odontoceti, which means whales with teeth rather than baleen and finally to the family of Delphinidae, so both descriptions are correct.
@Anthony Twidale the body temperature is to low for a killer whale but its possible...
@Dwayne LaGrou that's actually really clever!
Can the tag transmit from t he inside ? Maybe it was deactivated by the stomach contents of the biting predator?
@Barbara Hensen The sudden spike of temperature and the immediate increase in depth points the finger at another Great White or even an Orca. Not finding a carcass also would indicate being swallowed as opposed to being a victim of a feeding frenzy.
@Barbara Hensen That is an amazing hypothesis. Definitely a possibility! :)
Thank You for the compliment. I also had an idea about extending the power capabilities of the tags by having a small spinner on the trailing end that could harvest the power of the water rushing by as they swim. I know that sometimes people that are outside of the normal circle of scientists they can often come up with some really off the wall ideas.
Just my way of trying to help.
Thanks Again, Dwayne
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