15-foot shark with ‘distinctive bite wounds’ washed ashore. Now, DNA reveals killer

In October 2023, the mangled remains of a massive white shark washed ashore in southeastern Australia.

The 15-foot carcass was covered in bite wounds and stripped of its internal organs, leaving locals and scientists with the same question: What on Earth could have killed it?

Now — over a year later — DNA analysis has revealed how the mighty apex predator met its grisly fate, according to a study published on Jan. 27 in the journal Ecology and Evolution.

DNA reveals the killer

Using swabs, scientists gathered genetic material from the carcass’s “four distinctive bite wounds,” including one which measured about 20 inches across.

The swabs were then transported on ice to a laboratory, where the collected genetic material was extracted and analyzed.

This process uncovered the DNA of two animals: orcas, also known as killer whales, and broadnose sevengill sharks.

Orca DNA was linked to the largest bite wound, found in the center of the shark, which is “characteristic of liver extraction” — a technique orcas have been observed deploying.

The other three wounds were linked to broadnose sevengill sharks, which scientists believe scavenged from the white shark after it was killed.

The findings are unique because, while killer whales have been observed preying on white sharks off of South Africa and California, they have never been verifiably documented doing so off of Australia.

“These results provide confirmed evidence of killer whale predation on white sharks in Australia and the likely selective consumption of the liver, suggesting predations of this nature are more globally prevalent than currently assumed,” according to the study.

White sharks are found throughout the world’s temperate and subtropical waters, and they can grow up to 21 feet and live seven decades, according to the National Oceanic and Atmospheric Administration.

The study authors were: Isabella Reeves, Andrew Weeks, Alison Towner, Rachael Impey, Jessica Fish, Zach Clark, Paul Butcher, Lauren Meyer, David Donnelly, Charlie Huveneers, Nicky Hudson and Adam Miller.

This story was originally published January 30, 2025 at 12:40 PM with the headline "15-foot shark with ‘distinctive bite wounds’ washed ashore. Now, DNA reveals killer."