During more than 25 years studying a variety of fish, including sharks, James Sulikowski has had to solve all kinds of problems. Among the trickiest and most important: How do you gather data about pregnant sharks without first killing them?

[Michael Phelps to race a great white during ‘Shark Week’]

“The catch-22 is that you need the information to better manage them, but in order to get the information [you used to have to] kill them. You’re damned if you do, damned if you don’t,” Sulikowski, a professor at the University of New England in Biddeford, said. “So that’s where my sort of science came in. We treated sharks basically like pregnant females, like human beings. How are humans studied? Well, you take blood and you can look at that blood for circulating levels of hormones [to determine if the female is pregnant].”

[Reported sighting of great white shark clears Maine beach]

That idea morphed into taking special waterproof, veterinary-grade ultrasound equipment onto boats and examining sharks that later would be released alive.

That kind of newly available data on shark reproduction made Sulikowski and his colleagues rock stars in the shark world and drew the interest of the Discovery Channel.

When Discovery Channel’s popular “Shark Week” franchise returns for another wall-to-wall dose of toothy adventure in July, Sulikowski and his colleagues will be prominently featured. That episode, titled “Shark Vortex,” will air at 8 p.m. on July 24.

Sulikowski was tight-lipped about what viewers will see during the episode, which marks the second straight year his work will have been featured during “Shark Week.” In 2016, “Tiger Beach” kicked off Shark Week and drew between 6 million and 7 million viewers during three airings, according to Sulikowski.

“[‘Shark Vortex’] is top secret. I signed my life away for that,” Sulikowski said. “But I can tell you it’s a great story. It’s basically sharks of New England, in a sense. It’s gonna have white sharks, it’s gonna have makos, it’s gonna have porbeagles. The ones that really separate us from other places.”

A UNE press release was a little more forthcoming, though it may give pause to tourists preparing to dip their toes in the brisk Atlantic: “Each summer, the Gulf Stream pushes north into the waters of southern New England, bringing with it 30 species of shark,” according to the release. “Massachusetts shark biologist Greg Skomal and cinematographer Joe Romeiro study the annual spectacle, focusing on three sharks — makos, great whites and porbeagles — that can out-swim, out-think and out-compete all the others.”

On Monday, Sulikowski had a milestone day at sea, attaching the first-ever satellite tag to a pregnant porbeagle shark.

Sulikowski called catching the 8-foot shark “serendipitous,” because the fish needed help. It had been captured or nearly captured previously. A rope was wrapped around its tail, and it had been harpooned. Sulikowski couldn’t remove the harpoon but did take off the rope, allowing the shark to swim freely again. He estimated the shark had been previously handled or caught at least six months earlier.

Sulikowski has been working with Skomal and said Tuesday his UNE crew picked up some high-tech gear that will take advantage of some of Skomal’s work with great white sharks.

“We’re going to deploy it next week. When the [great white] sharks [that Skomal has attached radio tags to] swim up, we’re going to create a little gate, and when they pass that gate [into Maine waters], we’ll know,” Sulikowski said.

Yes, great white sharks — or simply “white sharks,” to shark biologists — are coming our way.

Sulikowski said he’s not sure the recent report of a great white shark off Wells Beach was really a white. A basking shark, which can sometimes reach lengths of 25 to 30 feet, is more likely, he said. But that’s not because whites don’t come to Maine. It’s because it’s just a bit too early to expect them here.

But a perfect storm is brewing in Maine waters, and Sulikowski expects more white sharks in the future.

“[White sharks] are looking for a food source, and there’s lots of seals on [Cape Cod, where the whites are swimming right now]. That’s why they hang out down there,” Sulikowski said. “And our seal population is exploding up here in Maine, so it’s only a matter of time before we’re going to see the same thing here that we have on the Cape. Which, for me, is going to be awesome, because it’ll give us lots to do.”

Not that swimmers should be overly alarmed, Sulikowski said.

“Sharks in general are misunderstood. Most people have this innate fear of sharks because of, you know, ‘Jaws’ and everything that we have grown up with,” he said. “But there is no doubt about it: In their environment, they are top predators. If they were killing machines, we would be in serious trouble.”

But that’s not the case, he said. Especially here.

“In Maine waters, it’s a great place to be,” Sulikowski said. “There’s never been an unprovoked shark attack in Maine. Our waters are pretty safe.”

But you’ve seen the movie. You’re still scared. Say you’re out there, swimming, and you see something that you’re absolutely sure is a big shark. What should you do?

“I would say, keep doing what you’re doing,” Sulikowski said. “Don’t freak out. That’s one of the worst things you can do. The shark, if it wanted to eat you, it already would have, probably. Just keep doing what you’re doing, leisurely making your way back to shore.”

And remember: There are plenty of more dangerous places you can be. The shark expert guarantees it.

“You have far more chance of being bitten by another human being on a subway in New York than you do getting bit by a shark,” he said with a chuckle.

John Holyoke has been enjoying himself in Maine's great outdoors since he was a kid. He spent 28 years working for the BDN, including 19 years as the paper's outdoors columnist or outdoors editor. While...