It’s a pitch-black morning off the coast of Manteo, North Carolina and researcher Sara Mirabilio is loading her gear into commercial fisherman Charlie Locke's boat. The day's mission? Find some sharks.
Mirabilio is working on a device that could prevent needless shark death, but to do that, she needs to test it on sharks in the dynamic Atlantic Ocean.
Finding sharks in North Carolina waters shouldn't be a challenge. This diverse coastline provides plenty of habitat choices, from sounds to estuaries to the open ocean. Species like Blacktip sharks, sandbar sharks and sand tiger sharks often pass through these waters or birth young in the sounds.
Conservation efforts in the 1970s and 80s has led to a recovery in some shark species. That's good news for ocean ecosystems, as sharks provide a valuable role as apex predators—they keep the food chain balanced. But it also means more interactions between sharks and humans.
"I get calls a lot about shark attacks and swimming. And is it safe to swim? Well, more vacationers, that trend's going up, shark's recovering, that's going up. So, it's just probability," said Mirabilio, a fisheries extension agent with North Carolina Sea Grant.
"So now you have more sharks out in the wild, which is a good thing, right? It means our conservation measures are doing what they're supposed to do, but it also means that now you have more interactions with fishing gear."
Accidentally catching and killing sharks —what's known as "bycatch"—is one of the main sources of shark death.
"Bycatch is the number one threat to sharks worldwide," said Mirabilio.
Not only that, but sharks can be especially stressful for fishers. Sharks and fishers often target the same prized catch, like grouper. So, if a shark sees a grouper hooked on a fishing line, it will steal it, costing the fisher the day's earnings and potentially getting caught on the line itself. Sharks often damage expensive fishing gear.
"They're trying to eat the fish out of the net," said commercial fisherman Charlie Locke. "And they just end up tearing up your net, and it's a $1,500 net, sometimes brand new. You put it in the water and I've had nets destroyed the first time I ever put it in the water."
"So it's really it's a lose-lose for everybody," said Mirabilio. "It's a lose-lose for the fisherman who want the prize catch and it's a lose-lose that we could kill sharks unintentionally that we don't want to kill."
That's why Mirabilio is testing out a device that could protect sharks and keep fishers from losing their hard-earned catch. It's a unit that when attached to a fishing line near a baited hook, creates a protective bubble around that hook. The device emits a random pattern of electrical pulses. Sharks are incredibly sensitive to electric fields. It's how the detect prey at close range.
"I equate it to a dog fence, an underground invisible fence for a dog, but not as shocking. It's like a tickle," said Mirabilio.
But now it's time to test the device. Locke runs a long line, with each hook bearing a single device. Half of the devices are turned on and half are turned off. After three hours, Locke reels in the hooks and Mirabilio collects data on how many sharks end up on hooks with the device turned off. That way she’ll have an idea of how well the devices worked.
And so far, so good. All the sharks Locke caught today ended up on hooks without the electrical pulse. Locke sells them to a local fishmonger at the end of the day so they don't go to waste.
"The results have been surprisingly positive," said Mirabilio.
Over the course of the study, hooks with a device turned on deterred sharks by more than 50 percent. Mirabilio is publishing her results and the next step is figuring out how to scale up production to make a viable product.
"It's still very much a beta version," said Mirabilio.
But for fishermen, a device like this could be a game-changer. It would allow them access to places they aren’t allowed to fish, without accidentally killing sharks we’re trying to protect.
"If it works, this would be a really important tool for fishermen to have," said Locke.
As some shark species recover, humans are having more interactions with them, from beachgoers to commercial fishermen. Catching a shark accidentally is a headache for fishermen: sharks tear up gear, they eat prized catch and they could get the fishermen in trouble legally if the species is protected.
Plus, sharks often die in the process. Bycatch is one of the leading causes of shark death worldwide. But researchers have come up with a way to save both sharks and protect gear.