David Johnston is an Assistant Professor of the Practice of Marine Conservation & Ecology at the Nicholas School of the Environment at Duke University. As a kid, growing up miles from the ocean, he fell in love with the dazzling underwater photography brought into his living room by television. Today, he uses radio telemetry to get a more detailed image of the behavior of the ocean’s magnificent mammals.
Conservation Biology is the scientific study of the nature and status of Earth's biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction and erosion of biotic interactions.
When did you discover you wanted to be a Conservation Biologist?
I grew up in a small town called Erin in Ontario, Canada - in between Lake Erie, Ontario and Huron - but very far from the ocean. It may sound cliché, but it was Jacques Cousteau that really hooked me on the ocean. I wanted to get underwater to see that remarkable world for myself. I started diving in Lake Huron, where there are lots of shipwrecks close to shore. It was scary and cold, even in summer, but I loved it.
What did you study in school?
I took a circuitous route to get to be a marine ecologist. I started work after high school as a wine steward at a resort in the Muskoka region. Then I worked at a ski resort in the Northern Rockies. It was incredibly cool to work in such beautiful settings, but I realized there was no real career for me in that business. I enrolled in university in the Marine Biology Program at the University of Guelph — at the time it was one of the best marine programs in Canada. It was a very hands-on practical program. I got to work in aquariums. While doing that, I ended up staying for a Masters in Zoology, studying marine mammals. I studied the levels of heavy metals in harbor porpoises across their range. We found out that there were regional differences and that the levels of some heavy metals stored in their bodies were declining. That was good news!
I worked in the non-profit sector for about three years before heading to Duke University to get a Ph.D. I had grown deeply interested in studying the importance of the huge tides in the Bay of Fundy to marine animals. It turns out that the wake of the giant Fundy tide behind Grand Manan Island concentrates food of sea birds, whales, and porpoises like a giant buffet. This was an impressive system, even visible from space. No one had scientifically studied the relationship between the physical structure of this island wake and the ecology of the Bay. I published that research in 2005.
Where did your career take you?
I began my career as a conservation marine scientist working for non-profit conservation organizations where I studied the impact of noise pollution on harbor porpoises. We found that they were very sensitive to the noises generated by salmon farms and that these sounds drove the animals from important habitats. I also studied what impact climate change would have on harp seals, work that my students and I continue today (see here and here).
After I completed my Ph.D. at Duke, I left the Bay of Fundy in Nova Scotia and headed west to Monterey Bay in California. I took a post doc at NOAA’s Monterey Bay National Marine Sanctuary and Monterey Bay Aquarium Research Institute. That eventually led me to Hawaii to lead NOAA’s growing whale research program in the Pacific Islands. One of my tasks was to survey the cetacean populations in the Pacific U.S. Economic Exclusion Zones. This was a great job. I took lots of cool trips on big ships across huge pelagic ocean wildernesses to tropical coral atolls. We published cool studies on tropical dolphins and new breeding habitats of humpback whales. I also got married during this time, and we had our first daughter in Hawaii. Living in Hawaii was amazing but it was expensive and far from family. So when the opportunity to work at the Duke Marine Lab arose, I decided to come back to the Atlantic.
What do you like about your job today?
I like being a conservation biologist. I don’t just study the animals in their habitats, I study the way human activities shape the lives of marine vertebrates. How do our actions impact feeding and breeding of marine mammals? How does eco-tourism affect these animals we love to look at so much? How do animals recover from shifts in human behavior? The gray seal research we are doing flips those questions and asks how are humans responding to the recovery of the gray seal? Gray seals were essentially extinct in US waters by the end of the 1800s due to human hunting. Now their populations are recovering. People are confused by their return - they seem like invaders, they are loud and obnoxious, and they conflict with some human activities. These are hard problems to solve, requiring patience, open minds and new approaches. I would love to find the right tool for the right job and my students help drive this process. We’ve got access to really powerful research technology now. In the old days, it was binoculars. Now it’s telemetry devices glued to animals recording lots of data and communicating with us by cell phone.
Also, I embrace the use of new technologies for communicating science my students bring to my lab. Our lab has created an interactive timeline for the web on spinner dolphin science and conservation, and the second phase of this communication endeavor is an iPad app that actually tries to channel human behavior. It helps communicate the results of our science, and tells tourists where the more sustainable tourism ventures in Hawaii are located. I am really excited about the idea of using these new digital technologies, not just for understanding the animals, but also for shaping human decision-making.
- by Lucy Laffitte