A huge great white shark that washed up on the South African coast had just shot a dolphin before a larger predator got them both.
Biologist Alison Towner shared photos on social media after the necropsy of the 4.5-metre shark, confirming that ‘orca predation’ was the cause of its demise.
Scientists were called to the scene after a resident came across the mutilated carcass at the mouth of the Nyara River on May 28.
The next day, veterinarians completed the examination of the corpse and extracted a common dolphin from its stomach, which had been neatly cut into four pieces.
The most telltale 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 pull out their livers through a clean incision in the shoulder
After a carcass was discovered on May 28, scientists determined that the shark had been killed by an orca due to teeth marks on its head and an even more telling clue: a missing liver.
The finding marked the 14th confirmed case of white shark predation by killer whales in South Africa since 2015 (Photo: A carcass washes up in Mossel Bay, South Africa in 2022)
The ‘significant’ discovery marked the fourteenth confirmed case of killer whale predation by white sharks in South Africa since 2015.
Scientists believe killer whales target sharks in the area for their livers, and a growing body of evidence suggests this behavior is becoming more common.
In 2017, five great whites washed up in Gansbaai without their livers. It wasn’t until May 2022 that drone footage captured two male orcas hunting the sharks and removing the vital organs with ‘surgical precision’.
The killer whales were called port and starboard because of their dorsal fins, which curve to the left and right, respectively.
Last February, 19 carcasses of seven gill sharks washed up near Towner’s home without their livers, causing her to immediately suspect the pair.
Biologist Alison Towner has been researching the bizarre hunting behavior for years
Her suspicions were confirmed in June, when Starboard was spotted hunting a great white shark near Seal Island, killing it within two minutes and turning up near a tourist boat with its liver in his mouth.
Orcas are highly social and often work together to capture large prey such as sea lions, whales and sharks.
However, mounting evidence of lone killings, such as in the case of Starboard, is shedding light on hunting possibilities previously unknown to researchers.
In most cases, the rest of the sharks’ organs were left intact, while their livers were pulled out through a clean incision in the shoulder.
One theory is that orcas evolved the behavior to protect their teeth from the coarse skin of sharks, as the liver alone is sufficient to provide a full meal.
Hunting behavior has been the subject of several research articles – and while it fascinates scientists, they also recognize its grim implications for the marine ecosystem.
As the populations of the great white shark and the sevengill, both top predators, are continually depleted or forced to migrate, this could have a dramatic effect along the South African coast.
One possibility is that prey species will experience an increase in numbers, disrupting the delicate natural balance.
There is also the potential for a phenomenon known as mesopredator release, in which populations of medium-sized predators increase rapidly once larger carnivores disappear.
The 4.5 meter long carcass washed up at the mouth of the Nyara River, revealing that the animal had eaten a dolphin shortly before its death
A pair of male killer whales, called port and starboard because of their left- and right-leaning dorsal fins, have been documented to engage in the strange hunting behavior
Towner and other experts continue to monitor orca hunting behavior and strive to better understand it.
Starboard’s lone victory over the great white was showcased in an article published in the African Journal of Marine Science in March.
Whale conservation expert Simon Elwen noted that orcascan quickly learn new hunting techniques independently or from others.’
Towner called the findings “groundbreaking.”
“The astonishing predation, off the coast of Mossel Bay, South Africa, represents unprecedented behavior that highlights the orca’s exceptional skill,” she said.