From the Colorado to the Mekong River, In Pursuit of Some Very Big Fish
By Zeb Hogan and Stefan Lovgren
The collaboration that led to our book—Chasing Giants: In Search of the World’s Largest Freshwater Fish—goes back almost two decades. We first met in 2006 in Cambodia to start a National Geographic story series on The Megafishes Project, which was Zeb’s quest to find, study, and protect the largest freshwater fish species around the world. These animals—from giant catfish to gargantuan gars—are among the most critically endangered creatures on the planet, but they have for the most part been poorly studied.
Photo by Zeb Hogan. Stefan and team on Tonie Sap lake in Cambodia.
Our research has been a global undertaking, involving travels to rivers and lakes on all continents except Antarctica. But the book also has a strong connection to Nevada and the American West. We are both faculty members at the University of Nevada, Reno, which has supported much of our research, and we both live in the state. Zeb also got his start as a fish biologist working on the Colorado River, which features heavily in the book. Many people don’t know that the Colorado River is home to one of the largest freshwater fish species in North America, the Colorado pikeminnow, which was one plentiful throughout the basin. Historical records show the pikeminnow can grow six feet long, but fish that size are unheard of these days.
With such a broad topic, it was important to have a clear narrative thread running through the book. A hook, if you will. So we constructed the story around the search for the world’s largest species, the identity of which has long remained somewhat of a mystery. But this is also the story of the environments in which these fish live, our rivers and lakes. Giant fish are like the canaries in the coal mine; their plight tells us our freshwater systems are in trouble, under increasing threat from planned dams, pollution, habitat loss, sand mining, and climate change. This is an urgent crisis that has not been well reported.
Photo courtesy of Zeb Hogan. The Wonders of the Mekong team at Angkor Wat in Cambodia.
We were clear from the beginning that our book must be well grounded in the science. At the same time, we wanted it to reach the broadest possible readership, not just scientists or experts with a specific interest in the subject. From working with National Geographic for many years—Zeb as a National Geographic Explorer and the host of the popular Monster Fish TV show, and Stefan as a long-time writing contributor—we have both adopted an approach of blending the science with captivating narratives. This, we believe, is what most readers look for in a story like this. It was also important to highlight the many positive developments that we see happening, from dam removals to sustainable fisheries, in order to leave the reader with a sense of hope that this is not a lost cause. The truth is there are many people around the world who are tirelessly working to protect the rivers, lakes, and wetlands that sustain so much of life on Earth.
Photo courtesy of Zeb Hogan. Zeb and a Cambodian colleague release a critically endangered Mekong giant catfish into the Tonle Sap River near Phnom Penh.
As for the mystery at the heart of the book—the question of what is the largest freshwater fish in the world—it proved much harder to solve than either of us had imagined. In fact, by the time the manuscript had been finalized, we still didn’t have an answer. But then one day, we got a call from some fishers on the Mekong River who had made a very big catch. Thankfully, there was still time to add an epilogue…
To learn more about Zeb Hogan, Stefan Lovgren, and their work with Nevada Humanities, take a look at this YouTube video from their 2023 Meet the Authors conversation (together with author Bonnie Kelso) in celebration of the National Book Festival and Nevada Center for the Book recognition for their book Chasing Giants: In Search of the World’s Largest Freshwater Fish. This book was selected as a Nevada Center for the Book Great Reads from Great Places 2023 book selection.
Dr. Zeb Hogan is a research biologist at the University of Nevada, Reno, the United Nations Convention on Migratory Species Scientific Councilor for Fish, and host of the National Geographic television series Monster Fish. Zeb's research focuses on fish ecology, aquatic biodiversity conservation, and fisheries management.
Photo courtesy of Zeb Hogan. Zeb Hogan with a wallago catfish in the Malaysian rainforest.
Stefan Lovgren is a research scientist at the University of Nevada, Reno, and a journalist with 25 years of international reporting experience. He is a frequent contributor to National Geographic, often writing about freshwater issues. Chasing Giants is his fourth book.
Photo by Elliot Lovgren. Stefan Lovgren at the Grand Canyon.