Many people assume great white sharks dominate the aquatic food chain. It’s the largest and deadliest predatory shark in the world with hundreds of dagger-sharp teeth. So many people were shocked to witness a pod of killer whales attacking and killing at least two great white sharks off Mossel Bay in South Africa. Although researchers already knew that orcas occasionally hunt sharks, this behavior has only appeared in three previous studies. But this is the first time this attack was captured with drone and helicopter footage, revealing new behaviors for killer whales and great white sharks.
Killer Whales Hunting Great White Sharks
The researchers released a clip of the footage followed by a 2022 report published in the journal Ecology. [1] “This behavior has never been witnessed in detail before, and certainly never from the air,” said Alison Towner, a great white shark biologist at the Marine Dynamics Academy in South Africa and the lead author of the report. “It’s probably one of the most beautiful pieces of natural history ever filmed.” [2]
The great white shark population off the coast of South Africa has been declining in the past few years. Their only known predators are killer whales, apex predators who also eat fish, squid, seals, and whales bigger than themselves. Since 2017, eleven great white sharks have washed ashore. The carcasses lacked their livers and hearts, proof that orcas had killed them. One theory for the decline in sharks in that area is killer whale predation.
“Killer whales are highly intelligent and social animals,” Simon Elwen, a co-author of the study and a marine mammal specialist at Stellenbosch University in South Africa. “Their group hunting methods make them incredibly effective predators.” [3]
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Starboard and Port
And now, with this footage, scientists can learn more about this behavior. It depicts a pod of five orcas chasing sharks for over an hour. One clip shows two killer whales cornering a shark while the third attacks it from below, and one of the other orcas bites into the prey. Researchers believe that three more sharks could have been killed during this hunt off-camera. One of the orcas is called Starboard and has a reputation as a shark-hunter. Another orca has similar infamy, Port, although he’s not featured in the footage.
“I first saw Starboard in 2015 when he and his close-associated ‘Port’ were linked to killing seven gill sharks in False Bay. We saw them kill a bronze whaler [copper shark] in 2019 — but this new observation is really something else,” said David Hurwitz, a whale-watching operator from Simon’s Town Boat Company. [4]
However, the following report didn’t explain why orcas pursue great white sharks. But Towner hypothesized they are after the sharks’ “lipid-rich, nutrient-dense liver[s]” that could encompass a third of the creature’s weight. But if this predation behavior catches on to other orcas, it could massively impact shark populations. This may be the case, since Starboard had hunted with four new killer whales.
The Effect on Great White Sharks
Researchers were able to analyze great white shark’s defensive behaviors. In this case, they tried to evade their predators by circling them and keeping them in view, similar to how seals and sea turtles react to sharks. However, this technique failed most likely because orcas hunt with companions.
“We first observed the flight responses of seven gills [sharks] and white sharks to the presence of killer whales Port and Starboard in False Bay in 2015 and 2017. The sharks ultimately abandoned former key habitats, which has had significant knock-on effects for both the ecosystem and shark-related tourism,” said Dr. Alison Kock, South African National Parks’ shark expert and marine biologist. [5]
To date, researchers have documented 11 great white sharks killed by orcas. But Kock says the actual number is unknown since shark carcasses usually sink, not wash ashore. Researchers noticed that sharks’ absences from their usual grounds become longer after every orca attack. At one point, they left for over a year. The fewer sightings of sharks near the coast have been blamed on overfishing and illegal hunting. But predators may be the real reason.
Keep Reading: SeaWorld horror as killer whales attempts to drown trainer in resurfaced footage
Sources
- “Direct observation of killer whales preying on white sharks and evidence of a flight response.” ESA Journal. Alison V. Towner. October 3, 2022
- “Video Footage Captures Orcas Killing Great White Sharks.” Smithsonian Magazine. Will Sullivan. October 11, 2022
- “Detailed observation of orcas hunting white sharks in South Africa.” Science Daily. Ecological Society of America. October 4, 2022
- “Aerial footage provides proof of orcas killing great white sharks.” CBS News. October 6, 2022
- “Watch A Great White Become an Orca’s Lunch in World-First Footage.” Science Alert. Carly Cassella. October 5, 2022