Mark Hahn first visited Woods Hole in 1966 when his father, who worked for Eastman Kodak in Rochester, N.Y., spent a week at the Marine Biological Laboratory on business. Left to his own devices, the eight-year-old boy wandered around the docks and spent hours at the National Marine Fisheries Service aquarium, fascinated with the fish, seals, and turtles on display. This nascent interest in marine biology remained quiescent while he pursued a B.S. in biological sciences at Harpur College of SUNY Binghamton and then a Ph.D. in biochemical toxicology at the University of Rochester School of Medicine and Dentistry. Given the opportunity to rekindle his marine interests through a Surdna Foundation postdoctoral fellowship at WHOI in 1987, he turned a one-year fellowship into a thriving research program in comparative and molecular toxicology that involves a large group of talented colleagues. Hahn lives on Martha’s Vineyard with his wife, a kindergarten teacher, and son.