According to several articles I have read online, apparently new evidence of Orcas (Killer Whales) eating sharks has been reported. A study which was published in the journal of Aquatic Biology, examined tissue samples in various pods of whales, and found the offshore whales prey on large Pacific sleeper sharks, salmon sharks, blue sharks and spiny dogfish. For years and years scientists believed that sharks such as the Great White species, were at the very top of the marine food chain. Now we see that this is not the case and that it is a mammal, the Orcas (Killer Whale) which should be properly placed in this position.
One source of information for this blog post was:
The scientific study in which this evidence was presented is available to all of us for reading. The title of this research article is "Shark predation and tooth wear in a population of northeastern Pacific killer whales" and was published in the Volume 11 number 3 of the Journal of Aquatic Biology, which you can access by clicking on the following link:
Here is a video which discusses the fact that some people viewed a Killer whale hunting down and eating a shark: source of video:http://www.youtube.com/watch?v=SS6NjdGLVZs