Nat Geo Explorer Bertie Gregory Reveals Misconception About Hammerhead Sharks for ‘Up Close’ SharkFest Doc

National Geographic’s annual SharkFest swims back onto screens Sunday, July 5, kicking off a week of under-the-sea viewing with an exciting doc, Hammerhead Sharks Up Close With Bertie Gregory, from Emmy-winning Nat Geo explorer Bertie Gregory (that’s him above).

It’s the first of many fin-focused films and shows this week, but what makes this one particularly unforgettable is its focus on the distinct hammerhead shark in Mexico’s Baja Peninsula, where Gregory and his crew spent four weeks searching for the elusive sharks. “The Baja Peninsula used to be this stronghold for hammerheads, and in the 1990s when the shark fin trade ramped up, their population fell off a cliff — a 97% decline. Now, there’s this glimmer of hope that they might be making a comeback. So, I wanted to go find out what was up,” explains Gregory.

Because of the dwindling population, it took Gregory and his crew over a week during the month-long shoot to even locate their first hammerhead. “One of the big misconceptions [about hammerheads] is that they’re bold and brave. They’re proper scaredy sharks,” he laughs. “You have to work so hard to get close to them.” To accomplish that task, they used rebreathers, special stealthy scuba gear that recycles the air and doesn’t create bubbles. (“I describe it as wearing a Harry Potter invisibility cloak,” Gregory says with a laugh.)

The sharks have a good reason to fear humans, though, as Gregory also examines the legal shark fishing trade in the area, a major reason for their vulnerable status. “A handful of humans are killed by sharks every year,” he says. “We hear about every single one of those in the news. Yet we humans kill over 150 million sharks per year. So it really does make you question who should be scared of who.”

Still, Gregory is quick to note that it isn’t the area’s legal shark fishers that are the bad guys, but the system as a whole. “It’s the job of the whole system to come up with alternatives for [the fishers] and reduce the demand,” he says. “They’re not the ones making the money. It’s people up the chain. One of the things I love about this series is that as well as getting to shining light on animals, we can shine a light on people, too. Like Gabino, my guide, who used to be a shark fisherman and now he makes money and his livelihood from a non-extractive industry, from wildlife tourism and sharing his passion and love for the ocean. That was a bit of hope.”

Even more hope: Gregory recently launched his own wildlife conservation initiative called Act 4 Wildlife, which takes his wildlife journey beyond just storytelling into action. “I’ve always felt like I need to do more,” Gregory tells us. “I have seen firsthand how wildlife in general, not just in the sea, is in trouble. And we can do so much to help with that. Films are made in three acts, but when we finish those three acts, we get people excited and inspired, and then we move on to the next place and a new story, right? Well, now, Act 4 is the fourth act where I use my platform and the amazing contacts I’ve made and the team I have, to really make sure that we make big, quantifiable impacts for the wildlife we film.”

After Hammerhead Sharks, SharkFest will continue throughout the week with World’s Biggest Mako, Attack of the Samurai Sharks, Shark vs. Giant Crocs, Shark Island Showdown, Sharks Reef Rivals, Great White Gauntlet, and more. Nat Geo will also continue to expand its Secrets Of… franchise with Gregory again at the helm in Spring 2027 with Secrets of the Bears.

Hammerhead Sharks Up Close With Bertie Gregory, Sunday, July 5, 9/8c, National Geographic; Streaming, Disney+ and Hulu