Courtesy Will AllenThomas Leszkiewicz awarded August 2025 Sea Hero.
Thomas Leszkiewicz
Year Dive Certified: 2012
Dive Certification Level: Advanced Open Water Diver
Expertise: Shark Conservation
Social Media Handles: tomekk_12
Thomas Leszkiewicz is a shark conservationist and co-founding director of Sherwood Scuba Marine Conservation (SSMC), which supports scientists and conservation organizations with cutting-edge gear, as well as provides them access to the logistics, connections and outreach capabilities of a major scuba brand. Thomas has also helped establish a Marine Protected Area at Clipperton Atoll, filmed scalloped hammerhead sharks around Malpelo Island for a documentary, and worked with white sharks around the world.
Q: Tell us more about your work as a shark biologist
A: The best way to summarize my work in shark conservation is with a line from Robert Frost: “I have taken the road less traveled, and it has made all the difference.” I’ve been fortunate to contribute to marine conservation efforts around the world—from being part of a team that established a Marine Protected Area at Clipperton Atoll, over 1,000 kilometers off Mexico’s Pacific coast, to tagging a whale shark at Cocos Island, and filming scalloped hammerhead sharks in Malpelo Island for a documentary.
I’ve swum with oceanic manta rays at the Revillagigedo UNESCO site, and worked with white sharks in Guadalupe Island, South Africa and even back home in Quebec. And yet, I often find myself grappling with imposter syndrome.
Despite these experiences, shark conservation has never been my main source of income. But I take comfort in knowing I’m not alone. Close friends like Jeffrey Gallant, an English teacher and leading expert on Greenland sharks; Will Allen, a renowned filmmaker behind titles like Sharkwater who also owns bars and restaurants in Montreal; and Jason Borkland, who owns car body shops in Austin, Texas and still managed to produce an award-winning conservation documentary—serve as a reminder that meaningful impact comes from how we choose to show up for a cause.
Related Reading: How Do I Dive Safely With Sharks?
Q: What is Sherwood Scuba Marine Conservation?
A: In 2016, Sherwood Scuba Marine Conservation (SSMC) was officially launched. Our mission was simple but essential: support scientists and conservation organizations with cutting-edge gear, and provide them access to the logistics, connections and outreach capabilities of a major scuba brand. My biology background and internships helped bridge the gap between what researchers truly needed and what the dive industry could provide.
The idea behind SSMC was rooted in giving back to the oceans. Most people are drawn to diving to experience the wonder of marine life—whales, dolphins, turtles and sharks. A lifeless ocean simply wouldn't inspire the same passion. SSMC was created to support those who dedicate themselves to protecting the marine environment, equipping them with state-of-the-art gear to help further their vital work. With my scientific background, I was able to roll up my sleeves and work alongside them in the field. The goal is to contribute directly and hands-on to conservation efforts.
Q: How is SSMC supporting non-profits globally?
A: Our first official project was tagging bull sharks in Cabo Pulmo—a remarkable three to four-day expedition that opened the door to much more. Since then, SSMC has supported Fins Attached and its research vessel Sharkwater across countless expeditions and many other groups like the NGO Centro de Rescate Especies Marinas Amenazadas (CREMA) throughout the Eastern Tropical Pacific: Cocos, Socorro, San Benedicto, Guadalupe and more.
Beyond equipment and expeditions, SSMC has also flown scientists to cities like Toronto and Montreal to speak about our collaborative work. Outreach is vital—not only to raise awareness, but because you never know who you might inspire. This approach not only deepens your understanding of the challenges scientists face but also reveals how to better support both their work and the ocean creatures they're striving to protect.
Q: What do you want readers to know when it comes to misinformation about sharks and the issues the species is facing?
A: In my opinion, Jacques Cousteau was right when he said, “We only protect what we love, we only love what we understand, and we only understand what we are taught.” These words capture some of the core challenges facing not just sharks, but marine life as a whole. I'm still taken aback when I hear sharks described as mindless killers waiting to attack humans. At the same time, portraying them as entirely docile does them a disservice. Sharks should be approached with both respect and the caution we extend to any apex predator.
Ultimately, this brings me back to Cousteau’s quote. I believe the greatest threat facing sharks—and the ocean more broadly—is indifference. I’ve been extremely privileged to travel the world in the name of shark conservation. But I understand that for many, daily life is full of personal challenges: work, relationships, and responsibilities. And the pace of the world isn’t slowing down—it’s only accelerating.
So how do we make people care amid so much noise? The answer, I believe, lies in education and inspiration. I regularly give shark presentations to schools, always free of charge. You never know who you might inspire—or how far that inspiration might ripple.
Q: What's been your most satisfying moment?
A: My first collaboration with Dr. Mauricio Hoyos of Pelagios Kakunjá remains one of the most rewarding experiences of my career. In 2016, we launched the inaugural external tagging project for bull sharks at Cabo Pulmo National Park. It was also my first project with SSMC, and I felt a mix of excitement and nerves—we had limited time and an ambitious goal: to tag as many of these powerful predators as possible. What unfolded surpassed all expectations. Over the course of just three days, we successfully tagged 18 individuals. At one unforgettable moment, right after tagging a massive bull shark, we suddenly found ourselves surrounded by a swirling school of curious sharks. The intensity of that encounter was humbling and awe-inspiring, etching those days permanently into my memory.
Related Reading: Orgcas: The Women Uniting to Save Sharks
Q: What's been your most surprising moment?
A: One of my most surprising and unforgettable moments came during a St. Lawrence Shark Observatory (ORS) expedition in the Gulf of Saint Lawrence. Led by Jeffrey Gallant, this two-week scientific mission was aboard the tall ship EcoMaris. It was relentlessly battered by gale-force winds—and eventually took a direct hit from the tail end of Hurricane Fiona.
Yet amid the chaos, we were granted a narrow window of calm. In that brief lull between storms, we witnessed and recorded by drone a rare and dramatic event: a complete predation of a grey seal by a white shark in Canadian waters—captured on video in its entirety, from start to finish!
Q: Who are your "sea heroes"?
A: A personal inspiration of mine was the Canadian filmmaker, Rob Stewart. His documentary Sharkwater came out at a pivotal moment in my life, just as I was deciding between pursuing a degree in Biology or Engineering. I had always been passionate about sharks, but living through the cold, long winters of Montreal made me doubt whether a career working with them was even possible. Then along came Rob—a young Canadian who was doing exactly that—his journey became the spark that ignited my own commitment to shark conservation.
I’ve also been incredibly fortunate to work alongside and personally know some of my sea heroes—people like Randall Arauz, a conservationist whose grit and tenacity have made a lasting impact in Costa Rica.
But one individual stands out to me above all: Dr. Mauricio Hoyos. He’s not only a colleague and mentor, but also a close friend. His guidance in shark biology has played a major role in shaping the person and professional I am today, and for that, I’ll always be grateful. Mauricio has dedicated years to studying white sharks at the remote Guadalupe Island, and his relentless drive to protect these animals has set the bar high for me.
Q: Is there anything we did not ask that you would like readers to know? Tell us what's important to you!
A: Don’t give up, and don’t give in. Success isn’t a straight line, and chasing your dreams is rarely easy. The path may be challenging, but the journey is absolutely worth it. One of my favorite quotes is from Steve Jobs: “You can’t connect the dots looking forward; you can only connect them looking back.” Trust that things will fall into place. Along the way, you’ll meet like-minded people and form meaningful relationships. And sometimes, your greatest mentors aren’t even alive—you can become friends with the eminent dead and learn so much. Reading is my favorite hobby, and I avidly collect books. Through biographies, I gained invaluable insight and wisdom from figures like Abraham Lincoln, Jules Dumont d’Urville, Albert Einstein, and many others.
Success isn’t linear. Don’t give up. Don’t give in. And never stop learning.
Each month in Scuba Diving, we feature a Sea Hero who has been nominated by their community members for their commitment to the advancement of conservation, education, and exploration. In our December issue, judges select a Sea Hero of the Year. Nominate a Sea Hero at scubadiving.com/seaheroes.
