Meet Jill Heinerth

Despite working at the outer edges of exploration, and in a field historically dominated by men, Heinerth has carved out a unique role. She moves between disciplines, collaborating closely with scientists while maintaining an independent voice rooted in exploration, communication, and conservation. And, she’s constantly on track to empower the next generation of women divers to expand on their skills and move into the technical realm. But now, her focus is turning toward a place she has always called home.

Today, Heinerth has turned her attention toward a hidden freshwater cave system tucked within the forests of Ontario’s Whitewater Region, where the Ottawa River disappears underground through a labyrinth of submerged passageways. The river moves through the landscape, stained brown by tannins released from surrounding trees. But beneath that darkened water lies an intricate network that few people have ever seen.

Heinerth’s current work comes at a time of growing concern over freshwater biodiversity loss and the long-term impacts of industrial development on river systems. The Ottawa River, which feeds into the St. Lawrence and eventually the Atlantic Ocean, remains one of the few relatively intact ecosystems in the region. Heinerth describes it as a place protected from human encroachment—especially when compared to nearby Lake Ontario. There, invasive species have dramatically altered the ecosystem but the water is noticeably clearer. “People see this kind of semi-clear water and assume it’s healthier,” she says. “But that’s not always the case. Not here, at least.”

In Lake Ontario, invasive zebra and quagga mussels have filtered the water so efficiently that it creates a clean illusion; while simultaneously collapsing native food webs. Native mussel populations have largely disappeared. By contrast, the Ottawa River still supports a diverse range of native species, including several types of freshwater mussels that play a critical role in filtering water and maintaining ecological balance. 

Heinerth held a critical, local Hickorynut mussel in her hand—plump, heavy—examining the difference between the invasive and native species. “It’s so hard to tell what belongs here and what does not,” said Jill. “This is why people are confused about what a healthy ecosystem looks like. And why I feel the need to play that educator role in my exploration work.”

Even for someone as experienced as her, the diving here in the Whitewater Region is technically challenging, and still only partially mapped. Even today, large sections remain unexplored. For Heinerth, that uncertainty is part of the appeal. “This is a lifetime project,” she says. “You don’t just show up and understand a place like this.” 

While Heinerth sounds like a scientist herself, she is not one by trade. Before becoming a full-time explorer, she worked in marketing and art. This unconventional path is what she says has shaped how she approaches her work. “I’ve always seen myself as a translator,” she said. “I take brutally tough scientific ideas and try to make them accessible.”

That role is central to her collaboration with Dr. André Martel who studies freshwater mussels. While Martel focuses on species identification and ecological analysis, Heinerth explores areas that are otherwise too difficult to document without her advanced diving skills. Underwater, she captures what she finds through video, photography, and detailed field notes, complete with impeccable sketches by her own hand. 

Together, they are building a deeper understanding of a system that has gone under the radar and unnoticed. That understanding is becoming increasingly urgent, especially with a proposed nuclear waste disposal facility on the community’s mind. Upstream from the cave system, the build of this facility is raising concerns about potential environmental impacts to these great waterways. Heinerth has been vocal about the need to better understand the ecosystem before major decisions are made. “You can’t protect what you don’t understand,” she says. “I know that’s been said by many others before me, but it’s still holding true to this day.” 

After more than 8,000 dives, Heinerth’s definition of exploration is constantly shifting, and her knowledge is still expanding. While her work has historically been about discovery, now, her work is equally focused on spreading a message about the human change needed. “Today, to be an explorer means to be a vehicle or a mouthpiece for conservation, protection, and restoration. I will always love going deeper and farther. But what I’m focused on now is looking closer,” said Heinerth. 

Finding thriving mussel populations and intact ecosystems offers both a warning and a possibility, according to Heinerth. “This is what a healthy system can look like,” she says. “We can see ecosystems rebound. I’ve seen it happen. It shows us what’s still possible, how resilient nature is. But only if we choose to protect what matters. Right now.”