Orcas unmasked: DNA reveals killers of great white shark that died mysteriously in Australia

Orcas (Image: Canva)

More than a year after a massive great white shark washed ashore in southwestern Australia, scientists have uncovered its true killers. The shark, found with deep bite marks and missing internal organs, sparked speculation. Now, DNA analysis has revealed that orcas and broadnose sevengill sharks were involved in the attack.

Orcas Confirmed as Predators
Scientists collected swabs from the bite wounds and conducted genetic testing. The results confirmed the presence of killer whale DNA in the primary attack areas. Researchers stated this was a "true predation event," ruling out contamination. The study, published in Ecology and Evolution, also found genetic traces of broadnose sevengill sharks, likely scavengers after the initial attack.

The carcass was discovered in October 2023 near Cape Bridgewater, west of Portland. Its condition, with large bite marks and missing organs, led to various theories online. Researchers noted that the bite patterns matched previous orca attacks on white sharks near South Africa, where orcas are known to extract livers from their prey.

Orcas Expanding Their Hunting Tactics
Killer whales usually prey on fish, sea lions, and penguins. However, recent studies show they also hunt other apex predators. Research published in Frontiers in Marine Science found that orcas have started targeting whale sharks.

Between 2018 and 2024, footage showed orcas using high-speed strikes to wound whale sharks before flipping them over. This technique prevents the prey from diving to escape. Once the sharks bleed out, orcas consume their nutrient-rich livers.

Scientists say these findings highlight the evolving hunting strategies of killer whales. Their ability to take down top predators like great white sharks and whale sharks reshapes our understanding of marine food chains.