A new study sheds light on the surprising ocean activity taking place off the coast of Cape Town, South Africa.
Over a decade ago, dive-boat operator Chris Fallows is believed to have been the first person to witness Cape fur seals chasing, killing and eating the internal organs of blue sharks.
In 2012, Fallows witnessed the same activity, and this time, he had an underwater camera to capture the action.
Fallows and his colleagues have published a study that seeks to explain the unusual behavior, according to New Scientist.
Seals and blue sharks are approximately the same size, and both tend to feed on smaller forms of marine life. While it is more likely that a shark would take on a seal or another sea creature of similar size, Cape fur seals apparently turn the tables on occasion.
It is not known how often seals attack sharks.
Researchers believe that the seals may attack sharks to reduce competition in the ocean for food. The seals also benefit from ingesting the energy-rich organs of sharks.