Joshua Stewart

Science. Conservation. Photography.

What I do
I'm a quantitative conservation ecologist, specializing in large marine vertebrates. I'm especially interested in finding better ways to protect mobile and migratory species, and supporting management decisions with quantitative science. I received my Ph.D. from Scripps Institution of Oceanography in San Diego, and have been an Associate Director of The Manta Trust since its inception in 2011. I'm currently a postdoctoral research fellow in NOAA's Cetacean Health and Life History Program, where I combine technology and quantitative approaches to improve our understanding of cetacean population dynamics.

Who I am
I grew up a city kid from New York, a world away from the tropical oceans where I now work. My escape was the American Museum of Natural History, where I would spend hours in the Hall of Ocean Life staring at frozen tiger sharks chasing sea turtles, or lying on the floor examining the throat pleats of a life-size blue whale suspended from the ceiling. The evidence of my obsession with the oceans started in elementary school, with drawings of nesting sea turtles and scuba divers surrounded by sharks. My connection with the oceans became more concrete as I took every available opportunity to volunteer on research and conservation projects, and went swimming, diving, sailing, kayaking—anything to get me in the water.

My third grade 'What I want to be when I grow up' drawing, and making my third grade self proud at Aliwal Shoal in 2010 (Photo credit: Paul Cowell)

When I started my undergraduate degree at Indiana University, it finally became clear that I could actually turn this obsession into a career. I enrolled in classes on fish biology and scientific diving, and volunteered for every field project I could find. The IU Office of Underwater Science focused heavily on underwater archaeology, so in between surveying fish biomass or coral recruitment on ‘submerged cultural resources’, I was helping excavate 17th century shipwrecks or search for the lost fleet of Christopher Columbus. I’m not sure how many hours I spent underwater over those four years, but it’s safe to say that salt water was coursing through my veins as I set out to start my career.

Photographing coral recruits on a cannon in the Dominican Republic with IU Underwater Science

My first year out of college I was lucky enough to spend a year as a Rolex Scholar through the Our World Underwater Scholarship Society. I traveled around the world learning about marine conservation priorities, and the many different approaches that dedicated experts are taking to improve the outlook of marine ecosystems. I spent time with conservation photographers, educators, and marine scientists. Of all of the systems or species I encountered, I was especially taken with manta rays after a month-long internship in the Maldives. These charismatic species are threatened globally by targeted fisheries and bycatch, and yet at the time we knew so little about their basic biology and ecology. Shortly after my first experience working with manta rays, I helped found The Manta Trust, and have since been working to improve our understanding of manta and mobula rays’ ecology and their conservation status. 

I did my PhD at Scripps Institution of Oceanography, which is what first brought me to sunny southern California. For my dissertation work I focused on filling knowledge gaps to improve the conservation and management of manta and devil rays. I was lucky to combine fieldwork in some pretty fantastic tropical locales with technology, lab analyses, and quantitative models to understand the spatial ecology, habitat use, and foraging ecology of these vulnerable critters. The work from my dissertation contributed to national protection for oceanic manta rays in Indonesia and Peru, and a significant increase in the size of a flagship marine protected area in Mexico. A variety of other projects on manta and devil rays grew out of my dissertation work, including ongoing projects on the movements and habitat use of juvenile manta rays in the Gulf of Mexico, population dynamics of oceanic manta rays in Pacific Mexico, and a collaborative project working to improve the post-release survivorship of manta and devil rays in tuna purse seine fisheries. 

In 2019 I made the jump from elasmobranchs to marine mammals and now focus on threatened populations of cetaceans (whales) for my position at NOAA. Despite a wide variety of protections enjoyed by whales in US waters, humans are still impacting their populations both directly and indirectly. I'm using a combination of fieldwork using cutting-edge drone technology and quantitative models to pinpoint exactly how certain impacts are affecting cetacean populations, provide early warning systems so we can respond to impacts before they get too severe, and determine what management solutions will have the greatest positive impact on population health. Right now I'm working on projects involving Southern Resident Killer Whales, Gray Whales, and North Atlantic Right Whales.​​​​​​​
I live in Solana Beach, California with my wife Madeline, who is an incredible graphic designer, science communicator, and all around great human being, and our incredible pup, Luna. I love the ocean and the outdoors, am an avid rock climber, and practice yoga when I have time or my back hurts. On this website you'll find more information about my research and conservation efforts, photography, and my full CV. Thanks for stopping by!

Family picture!

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