A huge white shark that washed up off the coast of South Africa had just devoured a dolphin before a larger predator grabbed them both.
Biologist Alison Towner shared photos on social media after the necropsy of the 15-foot-long shark, confirming that “killer predation” was the cause of its disappearance.
Scientists were called to the scene after a resident stumbled upon the mangled body at the mouth of the Nyara River on May 28.
The next day, veterinarians finished an examination of her carcass and recovered a common dolphin from her stomach that was carefully cut into four pieces.
The most telling signs of an orca attack were teeth marks on the creature’s head, plus an even more pressing clue: a missing liver.
Scientists have documented a strange phenomenon in which killer whales kill sharks and tear out their livers through a clean incision in their shoulder.
After a carcass was discovered on May 28, scientists determined that the shark had been killed by an orca due to tooth marks on its head and an even more telling clue: It was missing a liver.
The discovery marked the 14th confirmed case of white shark predation by killer whales in South Africa since 2015 (pictured: a carcass washes up in Mossel Bay, South Africa in 2022).
The “significant” discovery marked the 14th confirmed case of white shark predation by killer whales in South Africa since 2015.
Scientists believe orcas target local sharks for their livers, and a growing body of evidence suggests the behavior is becoming increasingly common.
Five white sharks turned up in Gansbaai without their livers in 2017. It wasn’t until May 2022 that drone footage captured two male killer whales hunting sharks and removing vital organs with “surgical precision.”
The killer whales were nicknamed Port and Starboard for their dorsal fins, which bend to the left and right, respectively.
Last February, 19 carcasses of seven sharks turned up near Towner’s home without their livers, leading her to instantly suspect the pair.
Biologist Alison Towner has been studying this strange hunting behavior for years.
Their suspicions were confirmed in June, when Starboard was seen hunting a great white shark near Seal Island, killing it in less than two minutes and surfacing near a tour boat with the liver in its mouth.
Orcas are very social and often work together to catch large prey such as sea lions, whales and sharks.
However, growing evidence of solitary kills, such as in the case of Starboard, sheds light on hunting capabilities previously unknown to researchers.
In most cases, the rest of the sharks’ organs were left intact while the liver was removed through a clean incision in the shoulder.
One theory is that orcas have developed the behavior of protecting their teeth from the rough skin of sharks, as the liver alone is enough to provide a complete meal.
The hunting behavior has been the subject of several research papers, and while it fascinates scientists, they also recognize its grim implications for the marine ecosystem.
As the population of white and sevengill sharks, both apex predators, is continually depleted or forced to migrate, this can have a dramatic effect on the entire South African coast.
One possibility is that prey species experience an increase in their numbers, upsetting the delicate natural balance.
There is also the possibility of a phenomenon known as mesopredator release, in which populations of medium-sized predators increase rapidly once larger carnivores disappear.
The 15-foot-long carcass turned up at the mouth of the Nyara River, revealing that the animal had eaten a dolphin shortly before its disappearance.
A pair of male killer whales, named Port and Starboard because of their left- and right-tilted dorsal fins, have been documented engaging in this strange hunting behavior.
Towner and other experts continue to monitor orcas’ hunting behaviors and strive to better understand them.
Starboard’s Lone Shot Down of Great White Shark Featured in Article published in the African Journal of Marine Sciences in March.
Whale conservation expert Simon Elwen noted that orcas’They can quickly learn new hunting techniques by themselves or from others.’
Towner called the findings “groundbreaking.”
“The astonishing predation, off the coast of Mossel Bay, South Africa, represents unprecedented behavior that underlines the orca’s exceptional ability,” he said.
