The great white shark is perhaps the most feared animal in the ocean. They are terrifying hunters and can attack and kill just about anything in the water, including humans.

While they aren’t nearly as likely to attack a human as many people would believe, they are certainly an apex predator that has almost nothing to fear. Starting in August 2023, however, it seems that something is giving these sharks a headache, literally.

Scientists have found a total of nine sharks dead on beaches since then. While this happens sometimes, it is usually pretty easy to tell what killed them. It could be an injury from a fight, damage caused by boats, or any number of things. For many of these sharks, however, the cause of death was not at all clear.

Researchers had to perform necropsies on them to figure it out, according to a New York Times report. They first did this early on when there had only been five known deaths. Megan Jones is a veterinary pathologist at the Canadian Wildlife Health Cooperator (CWHC). In the report, she said:

“Three of these five seem to have the same potentially infectious disease affecting their brain. We need to know more about what that is.”

The remaining four known great whites that have died arrived at beaches in the United States, indicating that whatever is causing these deaths is pretty widespread.

The Necropsies found that most of the sharks had meningoencephalitis, which is a condition where the tissues in the brain become inflamed. When it gets severe, it can result in the brain being pushed against the skull, causing a variety of different issues, including losing the ability to swim.

This disease is not extremely rare, but the rest of the condition of the sharks does not match up with them dying from meningoencephalitis in a normal way. For example, many of the sharks had full stomachs. If it were just the meningoencephalitis, they wouldn’t have been able to catch prey for some time before they died.

Trying to get to the bottom of this spree of dead great whites is difficult because there isn’t a lot of funding for research on sharks, especially when it would need a lot of resources to ship the shark bodies internationally to get them all together.

As of now, researchers will have to keep their eyes out for more dead sharks and monitor those that are living to see if they can pinpoint the cause and, hopefully, help prevent future deaths if possible.

Thought that was fascinating? Here’s another story you might like: Why You’ll Never See A Great White Shark In An Aquarium