In February of this year, 2023, a very strange incident occurred in South Africa. The residents of Cape Town were surprised to find 19 dead sharks.
What was astonishing was that their bodies showed no signs of being eaten.
The sharks were all Broadnose Sevengill sharks, and their bodies were completely intact except for one specific organ the liver.
Each shark appeared as if a skilled surgeon had precisely removed its liver, with no other missing organs.
However, the culprit was not a surgeon at all; it was an orca, the apex predator of the ocean and one of the most formidable hunters in the marine world.
The discovery of the culprit behind this incident was not an easy task for the general public.
However, for marine biologist Alison Towner, the answer was clear. Based on the distinct bite marks on the sharks, it was undoubtedly the work of orcas.
What puzzled her, however, was their precise targeting of the liver itself.
This behavior is not typical among orcas. All the sharks had precise incisions near the shoulder, resembling the work of a surgeon.
This indicates that the attack was not random but a deliberate targeting of a specific organ the liver.
orca size
The fact that orcas specifically target a particular part of the sharks' bodies without consuming them entirely is unusual.
This is especially surprising given that orcas can weigh up to 9 tons and require more than 200 kilograms of food daily to sustain themselves.
This incident was not the first of its kind, despite the high number of shark casualties. Since 2015, orcas have been observed hunting Broadnose Sevengill sharks.
At the time, it was known that these sharks gathered in specific areas of South African waters to avoid the great white shark, one of their largest and most formidable predators.
Even more astonishing is that the orcas did not stop at hunting Broadnose Sevengill sharks.
They also targeted the very predatory sharks that these sevengill sharks feared the great white sharks themselves.
orca vs great white
In 2017, orcas were observed targeting the largest sharks in South African waters this time, they were hunting great white sharks.
At the time, this event captured the attention of the media, journalists, and marine biologists, as it marked a significant shift in the marine predator hierarchy.
The great white shark, the largest predatory fish in the ocean, can weigh 2,200 kilograms (2.2 tons), grow up to 6 meters long, and possesses 300 razor-sharp teeth with a bite force capable of tearing 15 kilograms of flesh in a single bite.
Why does an orca whale hunt sharks just to eat their livers?
The secret behind the orca whale’s (Orcinus orca) targeted attacks on shark livers lies in their ability to detect the nutritional impact of their food.
Orcas benefit significantly from oil-rich diets, and there is no better source than shark liver oil especially from great white sharks.
The great white shark’s liver is packed with vitamins and hundreds of calories, all of which provide a significant energy boost for orcas.
Moreover, a shark’s liver makes up approximately one-third of its body weight, making it a nutritionally dense and sufficient meal, especially when the shark is large.
Orcas treat shark liver like an energy drink a quick, high-energy snack. Some researchers have even described their liver-hunting behavior as almost addictive.
Their intelligence is evident in their ability to precisely target this specific organ, ensuring they get the maximum energy boost with minimal effort.
The beginning of the phenomenon of shark liver eating in orcas
The first time scientists observed orcas hunting sharks in South Africa and specifically targeting their livers was through two male orcas known as Port and Starboard.
These two orcas were first sighted in the 1980s near the Canadian coast, and they became well-known due to their remarkable bond and constant companionship.
Although orca pods are known for their strong social bonds, the exceptionally close and long-lasting relationship between Port and Starboard was unusual.
Their connection stood out even more because they used unique vocalizations to communicate exclusively with each other.
Scientists found it easy to identify and track them due to their distinct communication patterns.
However, it wasn’t just their unique vocalizations that set them apart their dorsal fins were also visibly distinctive, making them easily recognizable.
Researchers believe that Port and Starboard’s strong bond may have helped them survive the dangers of the ocean.
This connection also highlighted their expertise in hunting and nutrition.
They were the first orcas ever observed feeding on shark livers, and over time, they became teachers for other orca pods.
Since then, this liver-hunting behavior has spread among different orca groups, making it a well-documented phenomenon.