He is a freshwater biologist who focuses on natural resource ecology and the conservation and invasion ecology of amphibians and reptiles. Before joining the University of Florida, he worked as the State Sea Turtle Program Coordinator in North Carolina, and as a research wildlife biologist with the U.S. Geological Survey. At the USGS, he coordinated efforts for the national Amphibian Research and Monitoring Initiative in the southeastern United States. Dr. Johnson's area of expertise is natural history and conservation of amphibians and reptiles, and he has worked extensively with imperiled species. He is a member of several professional societies, including the Society for Conservation Biology, Herpetologists League, and The Wildlife Society. He received his B.S. and M.S. in biology from the University of Central Florida, and his Ph.D. in wildlife ecology and conservation from the University of Florida.