The Dorsal Fin

The ITN News YouTube channel recently posted amateur video featuring a killer whale (Orcinus orca) attacking what appear to be broadnose sevengill sharks (Notorynchus cepedianus). The video was shot off the coast of New Zealand’s Blue Cliffs Beach, Tuatapere. One of the sharks beached itself, presumably to escape the orca.

Clinton Duffy, a marine scientist interviewed by ITN News, said that he expected that more orcas were present further from the shore and that the orca in the surf was likely trying to flush fish off shore for the other killer whales.

A recent study has found that orcas off of B.C. feed on Pacific sleeper sharks.

The Vancouver Sun is reporting that a new study shows through DNA evidence that offshore orcas (or killer whales) feed on Pacific sleeper sharks (Somniosus pacificus). The study was recently published in the journal of Aquatic Biology (Vol 11, No. 3).

According to the study, this is the first confirmed prey species of offshore killer whales, as well as the first record of Pacific sleeper sharks being prey items of orcas. Researchers believe that the abrasive skin of the Pacific sleeper shark is wearing the teeth of the orcas flat.

For more about the study, check out the full article at The Vancouver Sun.

Australian FX artist Greg McKee recently posted the above video to his YouTube channel, which features what appears to be a composite of “live-action” white shark footage and a computer-generated orca.

McKee work was featured in the animated film “Happy Feet,” in which he worked on the orca animation sequences. To check out more of his work head on over to Greg McKee’s website.

The video above from NatGeoTV.com presents a theory that a killer whale from the L.A. Pod of orcas might have used tonic immobility during a 1997 attack on a great white shark at the Farallones. The theory suggests that the orca (identified as “CA2″) potentially rammed the unsuspecting white shark, stunning it. While the shark was still disoriented the orca could have either grabbed the great white while it was on its back or flipped it over. The orca could have then held the shark upside down in its jaws, keeping it in a state of tonic immobility until the shark drowned.

While there is no hard evidence or clear-cut video footage of orcas inducing tonic on sharks in the NatGeo feature, the video does include video evidence of killer whales attacking stingrays in New Zealand using a similar technique. As seen in the footage, the killer whales approach the rays upside and grab them with their mouths, then right themselves, so that the rays are upside-down and effectively immobilized. Researchers hypothesize that if orcas have learned to use this technique on rays, then it’s not far-fetched to assume they could use a similar technique on sharks.

On a side note, some of the underwater footage of the “great white shark” in this clip features a shark that is clearly not a white shark. While I admittedly am not great at identifying certain species of sharks, I’m guessing the footage features either a lemon shark or a bull shark. Anybody care to enlighten me on the species seen at around 3 minutes in?

Thanks to DeepSeaNews.com for the video find.

Numerous media outlets are reporting that a female Sea World Orlando employee was fatally attacked by an orca today. Orlando’s Local 6 identifies the orca involved as Tillikum, a 12,300 lbs. male. Park manager, Dan Brown, identified the victim as being one of the park’s “most experienced trainers.” According to the Local 6 report, the victim slipped and fell into the orca’s tank and was subsequently attacked by the orca.

Unfortunately, it seems that orcas have become just as susceptible to media sensationalism as sharks. This ABC clip is a prime example…

The clip plays out more like a guy announcing a pro-wrestling match than it does a news story. This is an incredibly tragic story, as such, it needs to be handled objectively with journalistic integrity, instead of being covered like it was a monster truck rally.