Great White Sharks Bullied, Become Food for Killer Whales

Great White Sharks
Great white sharks have long dominated the seas, however killer whales, which are reportedly bullying the great beasts and sometimes eating them, may challenge their authority underwater. The research on this phenomenon is not very extensive, but is showing some promising progress in the realm of understanding why killer whales have started attacking great whites. Some researchers are taking advantage of the opportunity to explore how this new breakthrough can help deflect sharks from coastal areas and popular beaches where high numbers of surfers and beachgoers congregate.

The Farallon Islands, located off the San Francisco coast, are a critical base of research, where scientists monitor—among other things—13 different species of birds, five pinniped species, and great white sharks. The researchers studying the fierce predators arrive to the Farallon Islands in the summertime, when white sharks are known to frequent the area in order to feed on the abundant numbers of pinnipeds, or seals. This season is known to last through the fall months.

It all started back in the late 1990s when a group of researchers made the annual trek to the Farallon Islands to observe the great white feeding season. They recorded the presence of killer whales in the area, which also feed on the pinnipeds, and thereafter witnessed a killer whale bully a great white. The orca proceeded to kill the great white. Researchers also noted that great white sightings ceased following the event. It was still the height of the feeding season.

A 2014 report of predatory activity at the Farallon Islands mentions a similar happening in 2009. Following a “depredation event” on a great white shark by a killer whale, the remaining white sharks left earlier than normal, as if bullied out of the area. Researchers also observed a pod in the area this past fall, and wonder if that had anything to do with the lower-than-average number of shark predations on pinnipeds for the season.

The connection between great whites and orcas has attracted the attention of many marine researchers. In western Australia, documentary makers are looking to experiment with killer whale audio to see if it will deter sharks in the immediate area. Researchers have over three hours worth of audio to work with, so they hope that in observing shark responses they can isolate the specific killer whale sounds that are the most effective shark repellants.

Eyewitnesses have reported different killer whale bullying methods. In some cases the whale rams the great white shark, effectively “stunning” it by catching it off-guard. In other more elaborate scenarios, the killer whales engage in what has been dubbed by one researcher, Dr. Ingrid Visser, as the “karate chop.” In this case, the killer whale produces a vortex by way of an “up-thrust of its tail” in the open water, forcing the shark up to the water’s surface. At this point, the killer whale “pivots,” raises its caudal fin out of the water, and slams down with the entire force of its tail. The blow is reportedly devastating to the white shark.

Despite the initial difference in methodology, all killer whale attacks on sharks include one vital element: flipping the shark upside down. This apparently induces what is called “tonic immobility,” an unlearned reflex that induces a trance-like stupor. The killer whale continues to hold the shark down in this position causing it to suffocate, according to the reports.

There has been a great deal of speculation as to why the killer whales have engaged in this kind of deadly bullying behavior, and some researchers suggest that it is not necessarily “new” behavior so much as it is newly observed behavior. Others propose that it is a matter of resource competition. Killer whales and great white sharks are known to feast off of the same food sources. Regardless of the reason, some researchers are taking advantage of the opportunity to make beaches safer for beachgoers. Killer whale audio may prove to be a deterrent for great white sharks, although the effects and implications of faux whale calls on actual killer whales in the vicinity should be considered.

By Courtney Anderson

Sources:
Shark Trust
Point Blue
The West Australian Regional
The Telegraph
Marine Science Today

9 Responses to "Great White Sharks Bullied, Become Food for Killer Whales"

  1. Lee Winters   December 18, 2016 at 6:31 pm

    Some researchers believe orcas could have played a role in the extinction of megalodon.

    Reply
  2. luke   August 1, 2015 at 1:27 pm

    Bullcrap!! The orca in the video killed a huge white shark, about 16 ft long. An adult not a small baby white. Scientists now believe orcas see white sharks as food!

    Reply
  3. Steve   March 28, 2015 at 2:39 pm

    The vortex tail smashing wasn’t for a great white, it was observed that orcas did this to small mako sharks, much less sizeable than a great white. Great whites are way too big for orcas to engage in a tail smash. Generally orcas deter great whites by both their overall larger body size and the fact that they will attack the great white in groups. Orcas generally attack sharks species that are far smaller than them, and the rarity of predatory observations on great whites suggest that orcas understand they would be very dangerous prey to tackle, particularly a large full grown great white. The only known account of a one on one predation involved a juvenile shark of 10-12 feet long versus an adult orca about 16-20 feet long. Huge difference in size and experience.

    Reply
  4. Wayne   December 2, 2014 at 6:17 pm

    False facts. There was one documented attack on a GW in which the juvenile GW A) Wasn’t consumed. B) The shark went TOWARDS two KWs not away. Therefore one can deduce that GWs have no fear of KWs and KWs dispatched the shark to eliminate a threat. Gosh people are ignorant.

    Reply
  5. Franki Selby   November 23, 2014 at 12:39 am

    I don’t even know why killer whales attack great white sharks? Maybe it’s because they are aware of any humans swimming above them and just want to keep them protected. It’s the same with dolphins because sharks are afraid of them. When people are in trouble, dolphins are supposed to fight off sharks by using their high speed blows. I have to say that they are aware of the danger people are in because they think that we are on their team.

    Reply
  6. Penny Watkins   October 16, 2014 at 7:38 am

    What a stupid article. Yeah killer whales just like to flex their muscle in push whitey around. Killer whales don’t play with their food AND waste it. They eat whatever they “bully” around if it dies.

    Reply
  7. Al Raymond   August 29, 2014 at 2:05 pm

    Some experts deplore the slaughter of sharks on the ground that they are needed to keep an ecological balance in the oceans. But many shark species are man-eaters, whereas orcas—which hunt the same kinds of prey—are not. So why not declare “open season” on those sharks known to be man-eaters, while focusing our efforts on protecting orcas from man-made pollution?

    Reply
  8. No Bite   July 25, 2014 at 12:01 am

    killer whale calls do deter sharks. and you can now wear them on your wrist or ankle… kck.st/VYlq2N

    Reply
  9. Paul Lundgren   May 20, 2014 at 8:17 pm

    “resource competition” might better serve the Orca to be labeled as “survival behavior” rather than “bullying behavior.” The implications of the labels we choose to describe nature should be considered with reverence. I hate to see a report that serves as propaganda of one species against another. Killer whale?

    Reply

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