Death series raises eyebrows: What's killing all the great white sharks?

USA/Canada - Great white sharks are considered the kings of the seas, apex predators without predators - the largest predatory fish in the world. Yet strange things are happening in the Atlantic: numerous specimens have died within a relatively short period of time. Researchers are in need of an explanation.

Within a few months, a handful of dead great white sharks have washed up in Canada.
Within a few months, a handful of dead great white sharks have washed up in Canada.  © dpa/Drone Fanatics SA | Christiaan Stopforth

Canadian wildlife authorities have not recorded a single dead great white shark in more than three decades! The cartilaginous fish, which are several meters long and weigh up to three and a half tons, can live for 40 (females) to 73 (males) years.

But in the course of just one year, five dead animals suddenly washed up on the Canadian coast, as the IFLScience portal reports. Four shark carcasses had also previously turned up in the USA. In all cases, the circumstances are mysterious.

The sharks were not killed, nor did they die because they starved to death. The only striking similarity? Meningoencephalitis! But the combined inflammation of the brain and meninges is actually just a symptom, not a disease in its own right.

The cause remains a mystery.

Great white sharks are dying of meningoencephalitis! But why?

This undated photo published by "Frontiers in Marine Science" shows a young great white shark.
This undated photo published by "Frontiers in Marine Science" shows a young great white shark.  © dpa/PA Media | Patrick Rex/California State Uni

"We know very little about what natural diseases affect wild sharks compared to other marine species," Harley Newton, chief scientist and veterinarian at OCEARCH, admits to IFLScience.

While it is worrying that several sharks of the "same size/age class/species" are showing signs of this specific inflammation, Newton also questions "how much of a concern this should be, as we don't understand how this fits into the overall picture of wild shark health."

Shark conservation researcher David Shiffman emphasizes in an interview with the portal that sharks are not doing particularly well overall. "They are one of the most endangered vertebrate groups in the world."

However, Newton explains that she does not expect the cause of the inflammation of the brain and meninges to be found in the near future.