A team of scientists from the area dissected all three of the sharks, and concluded that orcas were responsible for killing the great whites and removing their livers. (One also had its heart removed, likely by a hungry killer whale.) This organ has a high level of squalene, a hydrocarbon that’s an important for producing steroids and hormones.
“Obviously this is a very sad time for us all, nature can be so cruel and the dexterity these enormous animals are capable of is mind blowing, almost surgical precision as they remove the squalene rich liver of the white sharks and dump their carcass,” writes Alison Towner, a white shark biologist for the Dyer Island Conservation Trust who led the dissections, in the Marine Dynamics blog.
Orcas are very smart, and have different behaviors for hunting different animals around the world. It is possible that the creatures have now learned to go after killer whales. In 1997, whale watchers off the coast of San Francisco, near the Farallon Islands, filmed a killer whale attacking a great white, after flipping it over.
When turned upside down, many sharks become nearly comatose, and thus easy prey. Samuel Gruber, a researcher at the Bimini Biological Field Station in the Bahamas, said orcas could develop and spread new such hunting tricks. “Their learning abilities are so great, that if one of them happened to” flip over and stun a shark, “and see that [sharks freeze up] in this state, they could communicate it to the other ones,” Gruber says in a National Geographic film.
Full story: Newsweek