Serial killer whales have been murdering sharks and eating their livers for 5 years

A killer whale killing spree is taking place off of South Africa.

At least eight great white sharks have been torn apart and eaten by a pair of male orcas since the beginning of the year. Some of the sharks were missing their hearts.

It's not unusual for orcas to kill everything from small fish to large sharks, sea lions and even blue whales. The authors of a new study say that the violent escapades of two individual whales had a direct impact on their habitat.

The area has seen a decrease in the number of great white sharks in the last five years. When the orcas are close to the coast, dozens of sharks have been avoiding certain areas. Sometimes tagged sharks disappear for weeks or months at a time, leaving behind territory that has been dominated by great whites.

In response to increased lion presence, a large-scale avoidance strategy has been seen by wild dogs in the Serengeti. The longer the great white sharks are away, the more frequent the orcas are.

East of Cape Town, is the location of Gansbaai. A year-round great white shark presence in the area has made Gansbaai a popular tourist destination.

Great whites are among the top predator in the water and can reach up to 16 feet in length. The sharks of Gansbaai met their match when two mature male orcas descended on the coast.

Like cartoon criminals, the orcas were easily identifiable by their scars, one of which had collapsed to the right, while the other was bent to the left. Local whale watchers named the orcas Port and Starboard. The great white shark that washed up on the beach was spotted by whale watchers.

Four of the white sharks that were found dead in the last two years had their bodies torn open. Live Science previously reported that sharks have a large, fattened liver which could give them a lot of energy and nutrition. Port and Starboard were seen in the area. More undiscovered shark carcasses may have been lost to the sea.

In the six months after the first shark's death, there was only one shark spotted every day. The detections of sharks with electronic transmitters dropped as well. Between three and eight tagged sharks were found in the area before the attacks. The number dropped to zero after a while. Within a few days of an orca attack, individual sharks swam hundreds of miles away. sharks stayed away for a long time before coming back

The mass shark migration has had effects on the local environment. The bronze whaler shark is a mid-level predator that has moved into the area. The bronze whaler has increased in number with the big guys gone. The team said that this shift could put pressure on the entire system.

Why is this killer whale spree happening? Scientists have observed a rare flat-toothed sub-species of killer whale in South Africa that seems to specialize in hunting sharks. It is possible that Port and Starboard are part of this group. The sudden appearance of orcas could be related to a decline in prey populations.

The ocean murder mystery requires further observations of whales and sharks.

It was originally published on Live Science