The scenes were captured on video by both helicopter and drone pilots off the coast of South Africa. It is the first direct evidence that orcas prey on the iconic fish particularly for their hearts and livers.
Alison Towner, a senior scientist at the Marine Dynamics Academy in Gansbaai, South Africa, was the lead author on a study cataloguing this behaviour.
She said: “This behaviour has never been witnessed in detail before, and certainly never from the air.”
The footage shows the giant fish being pursued, captured and incapacitated. Data from tags, drone surveys and shark tour boats also reveals terrorised great whites left the Mossel Bay region for several weeks.
Only two killer whales in South Africa have been previously linked to hunting white sharks, but had never been seen in action. Only one of that pair appears in the latest pictures along with four other orcas, suggesting the behaviour is spreading.
The study also sheds new light on sharks’ attempts to evade capture. On two occasions, orcas approached sharks closely and slowly. Their prey, instead of fleeing, stayed close, keeping the pursuers in view – a common strategy seals and turtles use to evade sharks.
However, orcas are social and hunt in groups, perhaps rendering the circling strategy ineffective for white sharks.
Co-author Dr Simon Elwen, of Stellenbosch University, said: “Killer whales are highly intelligent and social animals. Their group hunting methods make them incredibly effective predators.”
One infamous killer whale, locally known as ‘Starboard’, was part of the pod. It was seen eating a large piece of shark liver at the ocean surface.
David Hurwitz, a boat-based whale-watching operator from Simon’s Town Boat Company, said: “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 in 2019, but this new observation is really something else.”
An analysis of drone and cage dive boat survey data showed only a single white shark was seen in the 45 days after the predations.
Marine biologist Dr Alison Kock, a South African National Parks shark expert, said: “We first observed the flight responses of seven gills 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.”
Previous studies have documented how new behaviours spread among killer whales over time through cultural transmission.
The researchers suggest if more orcas adopt the practice of hunting white sharks, then the behaviour could have far wider impacts on shark populations.
Orcas are the iconic great white’s only predator apart from humans. The huge marine mammals can reach up to 30ft in length and weigh over six tons, feeding on fish, squid, seals and sea birds. Great whites are up to 22ft long and 2.5 tons.
The study, which used long-term sightings and tagging data, is published in Ecology. Over five-and-a-half years, 14 sharks were tracked fleeing the areas when the whales were present.
Visual sightings have dropped dramatically in certain Western Cape bays. Located 60 miles east of Cape Town, Gansbaai was world-renowned for seeing great whites.and tourists across the globe flocked to the site. Many took part in cage diving to see the legendary creatures up close in the wild.
The number of sharks in open oceans has fallen by more than 70 per cent in just 50 years. Three-quarters of species are threatened with extinction, including the great white because of climate change and overfishing.