Deterring Sharks With an Electric Field | Shark Attack Files
NARRATOR: 40 miles off the coast of South Australia, shark scientist Doctor Charlie Huveneers and PhD student Madeline Riley investigate the best way to fend off a shark attack. The answer may be to prevent it in the first place.
"And then we just need a few base ready. And you're good to go."
"All right, sounds good. Let's hope the sharks stick around. You first!"
NARRATOR: Their theory, that the sharks' ampullae of Lorenzini can be used against it. [music playing] They're testing a new shark deterrent that does just that.
"So sharks are capable of detecting minute electric fields. And the idea of this electric deterrent is to transmit a very strong electric field that will overwhelm that sense of the shark, so that as the shark gets too close, it's kind of nearly receiving a punch in the face. And the shark just basically deterred."
NARRATOR: There's a lot riding on this test. Most shark deterrents are designed to protect just one person. This one, which has been tested for two years, is much more ambitious.
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"If all goes well, it'll be powerful enough to keep sharks out of a section of the ocean 25 feet in diameter by 50 feet deep without harming any swimmers. That's bigger than most swimming pools."
"How it works is this big, white thing is a float. It just floats on top of the water. This black module is where the power comes from. And then underneath, we've got a 4-meter long electrode, which actually emits the electric field, which theoretically deters a shark."
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NARRATOR: The first thing they'll need to test the deterrent, sharks. Within moments, a 13-foot great white turns up.
"All right, we've got a shark coming in at the back."
NARRATOR: And seems curious about the device. A large piece of bait hangs near the electrode. If the shark's hungry, it'll have to fight through the electric field to get to it.
"The team will film the shark's reaction then analyze it after."
NARRATOR: The shark circles, clearly intrigued by the tasty morsel floating in the ocean.
"Coming back around."
NARRATOR: Scientists monitor the action as best they can from the deck. They know that the entire test is riding on this moment. Investigators wait to see if the great white will break through the constant electric current. The shark gets closer and closer with each pass but doesn't bite.
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NARRATOR: The team reviews the footage, looking for the telltale muscle spasm that signals that the electrical current affected the shark.
"Oh, did you see that? Oh, you can actually literally see the pectoral fin flicking down. Yeah."
NARRATOR: It's a subtle movement, but the slight flick of the shark's pectoral fin tells the research team the deterrent seems to work.
"That first flexing of the pectoral fin, that's a standard reaction to an electric field that we've seen in the past."
"Yeah. We're in the really early stages of this testing. But if we get more really good trials like we've had today, then we'll get a clearer understanding of how effective this deterrent actually is."
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