The kings of the sea have been killed one after another... How many mysteries are there in nature that need to be solved?

On February 9, 2017, a great white shark was found dead on a beach near Gansbaai, South Africa.

It was a 2.7-meter-long female shark with a scratch on its head, but its body remained intact. Marine biologists quickly rushed to the scene to check, but were unable to find out why the shark died.

The shark carcass was wrapped in a net and dragged away by researchers. This time, the great white shark, the king of the sea, became the victim | Marine Dynamics Shark & ​​Whale Tours

Even more confusing is that all the other great white sharks around have disappeared . This place used to be home to one of the largest populations of great white sharks on Earth, and tourists and researchers could easily spot sharks from boats - but this time, the great white sharks had not appeared for three weeks. They seemed to be afraid of something and fled the area overnight.

At that time, people did not know that a bloody ocean serial murder case was quietly unfolding.

The overlords of the sea were killed one after another

On May 3, 2017, researchers received another report: another dead great white shark appeared on the coast. This female shark was nearly 5 meters long and weighed more than 1 ton. Its death made the researchers feel particularly sorry.

At first glance, the shark looked normal—until the researchers flipped it over and saw a huge tear in its belly. Through the wound, the shark's internal organs were clearly visible, but the liver was missing .

The body of shark victim Khaleesi | Marine Dynamics/Dyer Island Conservation Trust

Then, the third dead shark appeared on May 4. Its abdomen was also ripped open and its liver was removed. In this male great white shark, researchers found important new clues: its pectoral fins were covered with scratches that looked like they were left by killer whale teeth .

Then, the bloodbath continued. By the end of June, people had found as many as six great white shark carcasses in different locations along the coast. Except for the first one, all of them were gutted in the same way and their livers were taken out.

The series of murders caused great panic among the great white shark group: human observations and acoustic tag tracking confirmed that after the murders, they collectively fled the waters and did not return for several months .

Shark carcasses continue to appear on the coast | AV Towner et al.

The killer combination emerges

Researchers have identified the suspects in this serial murder case: a pair of killer whales with a unique appearance.

The two "suspects" are both males, always traveling together. They both have collapsed dorsal fins, which are quite rare in wild killer whales , and one of them is fixed to the left, while the other is to the right - so people named them " Port" and "Starboard". Since 2015, they have been active here frequently.

Killer whales port and starboard | Kelly Baker/SharkWatch SA

People found that this pair appeared particularly frequently in 2017, and their appearance time was always closely related to the time when great white shark carcasses were washed ashore .

Although great white sharks are powerful predators, killer whales are superior in size and teamwork . Researchers speculate that this pair of killer whales (and possibly other killer whales) may have learned hunting skills against sharks , working together to kill them and eat their livers. As for the shark that remained intact at the beginning, it may have accidentally stranded and died while being chased by killer whales.

Diagram: Killer whales and great white sharks compared in size. This diagram assumes that the average killer whale is 6.5 meters long and the average shark is 4.6 meters long | The Nature Box / Wikipedia

Smart killer whales do not eat the whole shark, but only swallow the liver , because this is the most efficient way to obtain calories . The shark's liver is large and fat, sometimes accounting for 30% of the shark's body weight, of which the fat content can be as high as 80%.

The net of heaven is vast and the evidence of guilt is finally obtained

In the years that followed, people continued to see the port and starboard sharks from time to time. The killer whales may have eaten more great white sharks, but people have never directly observed their hunting process.

It wasn't until 2022 that this serial shark killing case finally saw a new turn: this time, people directly saw killer whales hunting great white sharks in the waters of South Africa and left a video record.

A killer whale cuts open the belly of a great white shark, and a cloud of blood spreads in the sea water | Christiaan Stopforth

The new hunting incident took place in Mossel Bay on May 16, 2022. A drone pilot and a sightseeing helicopter pilot captured some of the footage from different angles.

This time, there were five killer whales traveling together, one of which was the starboard with the collapsed dorsal fin. During the 71-minute hunt, at least two great white sharks were confirmed to have been killed .

Starboard! It's you! | Christiaan Stopforth

The video shows a killer whale following a great white shark closely. The shark did not run away immediately, but kept its eyes on the predator and dealt with it. If there was only one predator, this defense of monitoring and waiting for an opportunity to act could increase the chance of survival - but unfortunately, this strategy does not work for killer whales that are good at fighting in groups.

In addition to teamwork, the orcas also appear to have mastered the art of quickly subduing sharks. Before biting the shark, one orca attempts to roll the shark onto its belly — a position that triggers a reflex that temporarily freezes the shark.

Flipping sharks over can temporarily put them into a state of tonic immobility. Human researchers often use this method to tag and examine sharks, and killer whales appear to have mastered the same control technique | BlueWorldTV

The video also recorded the liver falling out of the shark carcass and floating on the sea surface, and the killer whale "starboard" gnawing on the liver .

The starboard side of a killer whale and a shark liver floating on the surface | Sea Search Research & Conservation

How many killer whales have joined the hunt for great white sharks? Is the local ecology changing as a result? Where did the port side that was not captured on video go? The serial murders are still going on , and researchers still have many questions to answer.

References

[1]https://www.tandfonline.com/doi/abs/10.2989/1814232X.2022.2066723

[2] https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecy.3875

[3] https://saveourseasmagazine.com/winter-is-coming/

[4] https://www.esa.org/blog/2022/10/03/video-footage-provides-first-detailed-observation-of-orcas-hunting-white-sharks-in-south-africa/

Author: Window Knocking Rain

Editor: Mai Mai

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