Why Sharks Attack Cage Divers | Shark Attack Files

It's a mystery. Great whites around the world have been attacking divers in cages. No one knows why this is frightening. Finally, Dr. Greg Scomo may have cracked the case. He thinks the sharks are chasing bait; they want to tease these sharks in tight to the cages. But that shark is going to be disoriented.

But there's a problem with Greg's theory; one case doesn't add up. What's going on here? It's clearly ignoring that first bait, and that first bait's actually pulled away from it. This great white seems to ignore the bait; it goes straight for the divers. No, you gotta understand, there's a lot of scent in the water.

So this shark is moving right around. Let me slow things down here. But look again, another clue: the shark goes to the back of the cages, and there you go right there. There's a bait box behind the cage, and the shark is checking out the bait box. This highlighted bait box is full of chum; it sends a powerful scent to the shark, but it's confused. It can't see any fish.

What's happened here is, as it accelerates toward that box, it realizes there's no room for it. The shark turns, but it's too late to avoid the cage. These are big animals. Yeah, they're fish that are incredibly agile in the water, but not when they're this size. You don't want to put the baits this close to where people are diving.

There's a way to test if Greg's theory is correct by seeing how sharks react to cage divers when they are drawn in by something other than bait. In Australia, marine biologist Melissa Marquez and boat operator Matt Waller will attempt to attract sharks using music. This experiment is a real opportunity for us to learn something new.

Melissa wants to see for herself if great whites will still attack a cage when drawn in by something other than bait. "Good to go!" As if there's other stimuli such as just vibrations and there's not food, they might act a little bit different.

"I'm gonna put her in the cage; we're gonna hand her our underwater speaker." [Music] Melissa thinks music with low frequencies will best pique the interest of the sharks, but will it also lead them to ram the cage? "What kind of frequencies are we talking?" "Around 40 hertz." [Music]

"Coming your way! Get ready to rock out!" [Music] A big great white comes in, not following its nose or its eyes. [Music] It travels four times faster underwater than it does through air, and great whites have ears to hear it. A small ear hole sits behind each eye.

They are able to [Music]. [Music] The shark comes in to check out the concert but shows no aggression at all. [Music] It's evidence that no bait means no risk of a cage attack. Acoustic attraction may offer the benefits of bait without the risks. [Music]

"Do you think we're crazy or we're actually onto something maybe different here? We're seeing results here. And like a lot of things with great white sharks, more research has got to be done."