Have you ever wondered what sound a shark makes?
Scientists at the University of Auckland in New Zealand believe they may have the first recording of a shark actively making noise.
In a study in the journal Royal Society Open Science, researchers found that the rig shark, native to New Zealand, occasionally makes a clicking sound.
"The discovery was purely accidental," lead researcher Carolin Nieder, who's a marine biologist at Woods Hole Oceanographic Institution, told Morning Edition.
The that the scientists were studying is a small shark, growing to just about 5 feet in length. Nieder said the noise it makes sounds a bit like a spark of electricity or a click, click, click.
Nieder's research had previously focused on how sharks hear, rather than their sound production.
"For me, coming from the field of fish bioacoustics, I didn't expect sharks to make sounds at all," Nieder said.
Then, one day, while observing rig sharks, she heard a clicking sound coming from one of the sharks.
"I was like, oh my God, I think they're making some sounds," Nieder said.
That initial discovery was in 2021 — when she and her team began observing rig sharks in tanks, with underwater recording equipment.
The researchers noticed that whenever a shark was held, it would start clicking – possibly, Nieder said, the sound of the sharks' teeth snapping together.
They also observed that the sharks did not make any noise when swimming, meaning that the clicking could be a stress response.
Even though she made the discovery nearly four years ago, Nieder and her team weren't able to publish their findings until last week. (Nieder first had to finish up her Ph.D.)
Nieder believes the study's findings add a layer of complexity to the already mysterious creatures.
"No one had really heard a shark making sounds before," Nieder said. "And then also, they don't have any specific structures that would stand out, that could make sounds."
Many fish, Nieder said, have a swim bladder, used for buoyancy, that can also make noise. But sharks don't have swim bladders.
For a long time, Nieder said, sharks have been viewed as silent – which to them getting kind of a bad rap.
From films like "Jaws," to "Deep Blue Sea," and even "Sharknado," sharks are often characterized as fearsome creatures. (The silence of the sharks in these movies can make them seem even more scary because their prey can't hear them coming.)
But Nieder emphasized: There are of sharks. And a lot of them are like the rig shark — smaller bottom-feeders, eaten by larger sharks and humans alike.
"I hope it will incite curiosity in people about sharks and sound — things that they hadn't considered before — and maybe prompt people to listen to sharks in the wild," Nieder said.
The radio story was edited by Ashley Westerman, and Majd Al-Waheidi edited the digital version.
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