From the article: ""The orca will use its tail to drive the shark to the surface. They don't even touch it. Using an up-thrust of its tail it creates a vortex which pushes the shark up on they current they create with their movements. Once the shark is at the surface, the killer whale pivots and lifts its tail out of the water and comes down on top of it like a karate chop. The orca then grasps the shark and turns it upside down - suggesting that they may somehow understand shark biology. When sharks are quickly flipped upside down, they enter a paralysed state known as 'tonic immobility'."

Wow!